EP2896927B9 - Accessory mounting hand guard for firearm - Google Patents
Accessory mounting hand guard for firearm Download PDFInfo
- Publication number
- EP2896927B9 EP2896927B9 EP15150538.5A EP15150538A EP2896927B9 EP 2896927 B9 EP2896927 B9 EP 2896927B9 EP 15150538 A EP15150538 A EP 15150538A EP 2896927 B9 EP2896927 B9 EP 2896927B9
- Authority
- EP
- European Patent Office
- Prior art keywords
- barrel
- hand guard
- barrel nut
- housing
- flange
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F41—WEAPONS
- F41C—SMALLARMS, e.g. PISTOLS, RIFLES; ACCESSORIES THEREFOR
- F41C23/00—Butts; Butt plates; Stocks
- F41C23/16—Forestocks; Handgrips; Hand guards
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F41—WEAPONS
- F41G—WEAPON SIGHTS; AIMING
- F41G11/00—Details of sighting or aiming apparatus; Accessories
- F41G11/001—Means for mounting tubular or beam shaped sighting or aiming devices on firearms
- F41G11/003—Mountings with a dove tail element, e.g. "Picatinny rail systems"
Definitions
- This invention relates to firearms in general, and in particular, to hand guards for firearms that enable various accessories to be mounted thereon reliably and efficiently.
- Firearms such as the M16 and M4 rifles adopted for use by the U.S. military services, typically incorporate a hand guard made of a plastic or composite material, by which the shooter can effectively grasp a forward portion of the barrel of the weapon, e.g., for carrying, aiming and shooting the weapon effectively. Additionally, it is recognized that such firearms can often benefit from a variety of shooting accessories coupled to the weapon, such as lights for illuminating targets or sighting devices, e.g., laser targeting devices. Responsively, the prior art is replete with examples of devices, including hand guards adapted to replace the stock hand guard provided on the rifle, that are designed to enable one or more accessories to be coupled to the weapon.
- EP 2653823 describes a hand guard including an elongated tubular housing comprising an upper part, a lower part and a lumen configured to substantially surround an intermediate portion of a barrel of a firearm.
- Each of the lower and upper part being provided with at least one rail adapted to receive an accessory to be mounted thereon.
- the rail may be a reduced-height Picatinny rail provided by the lateral side wall of the housing.
- US 2011061281 describes a hand guard rail system fastened to a firearm having a barrel and a barrel nut, with the hand guard rail aligned to the top rail of the firearm.
- the hand guard rail system includes a hand guard and a sleeve fitted into the hand guard. The sleeve and the hand guard are fastened to the barrel nut, thereby aligning the hand guard to the firearm.
- WO 2009082520 describes installing a hand guard on a firearm.
- the firearm includes a barrel, a barrel nut, and a delta ring.
- the delta ring is retracted away from the barrel nut.
- a number of hand guard members are positioned about the barrel.
- An annular groove associated with each hand guard member is mated with a portion of a flange of the barrel nut.
- the flange is secured within the annular groove of at least one hand guard member.
- the delta ring is advanced over a portion of some or all the hand guard members.
- US2012/0324775 discloses a clamp assembly with clamp elements on the barrel nut
- hand guards that permit a variety of useful accessories to be mounted on firearms are provided, together with methods for mounting the hand guards on the firearms quickly, reliably and without adversely affecting their accuracy.
- the invention provides a hand guard according to claim 1 and a method according to claim 6. Preferred embodiments are set out in dependent claims.
- a hand guard for a firearm such as a rifle, includes an elongated tubular housing comprising an upper part, a lower part, opposite open ends, and an elongated lumen configured to receive an intermediate portion of a barrel of a firearm longitudinally therein.
- An expansion collar is disposed at one end of the housing.
- the expansion collar includes an expansion mechanism configured to adjustably compress the expansion collar and the lower part of the housing longitudinally between a pair of surfaces respectively disposed at opposite ends of the intermediate portion of the barrel.
- a method for using a hand guard with a firearm comprises providing an elongated tubular housing comprising an upper part, a lower part, opposite open ends, and a lumen configured to receive an intermediate portion of a barrel of the firearm longitudinally therein.
- An expansion collar is also provided.
- the collar has a longitudinally extending tongue and an expansion mechanism configured to adjustably compress the expansion collar and the lower part of the housing longitudinally between a pair of surfaces respectively disposed at opposite ends of the intermediate portion of the barrel.
- the tongue of the collar is inserted into an end of the housing to form an assembly, and the assembly is mounted onto a lower surface of the intermediate portion of the barrel and between the surfaces thereon.
- the expansion mechanism of the collar is then adjusted such that the assembly is held in compression between the surfaces.
- a hand guard in another example, includes an elongated housing.
- the elongated housing comprises a lumen configured to substantially surround an intermediate portion of a barrel of a firearm, a side wall, and a pair of elongated slots disposed on opposite sides of the side wall.
- Each of the elongated slots defines a corresponding angulated face of a rail adapted to receive an accessory to be mounted thereon.
- the rail may be a reduced-height Picatinny rail provided by the side wall of the housing.
- a method in another example, includes inserting at least a portion of an expansion collar into an end of a part of a housing to form an assembly; positioning the assembly over an intermediate portion of a barrel of a firearm and between opposing surfaces thereon; and adjusting an expansion mechanism of the expansion collar such that the assembly is held in compression between the opposing surfaces by advancing a plurality of longitudinally extending screws respectively received in corresponding ones of a plurality of bores contained in the expansion collar such that a distal end of each screw is disposed in abutment with a bottom end surface of a corresponding one of the bores and at least a portion of each screw is loaded in compression.
- a hand guard for a firearm in another example, includes an elongated tubular housing having a lumen extending between opposite ends thereof.
- a hand guard mounting assembly is coupled concentrically to a rear end portion of the housing.
- the mounting assembly includes a pair of opposing transverse surfaces respectively disposed on opposite sides of a transverse flange located on a front end of a barrel nut extending forwardly from a receiver of the firearm. At least one of the transverse surfaces is longitudinally moveable toward the other transverse surface.
- a mechanism adjustably urges the at least one transverse surface longitudinally toward the other transverse surface so as to clamp the flange firmly between the two transverse surfaces and such that the barrel of the firearm is disposed concentrically within the lumen of the housing.
- a hand guard for a firearm of a type that includes a barrel and a barrel nut extending longitudinally forward from a receiver of the firearm.
- the hand guard includes an elongated tubular housing having a lumen extending between opposite ends of the housing; a mounting assembly coupled concentrically to a rear end portion of the housing, the mounting assembly including a pair of opposing transverse surfaces respectively disposed on opposite sides of a transverse flange located on a front end of the barrel nut, at least one of the transverse surfaces being longitudinally moveable toward the other transverse surface so as to clamp the flange firmly between the two transverse surfaces and such that the barrel of the firearm is disposed concentrically within the lumen of the housing; and a mechanism for adjustably urging the at least one transverse surface longitudinally toward the other transverse surface.
- a method for attaching a hand guard to a firearm of a type that includes a barrel, a barrel nut, and a forwardly biased slip ring extending longitudinally forward from a receiver of the firearm.
- the method includes providing an elongated tubular housing having a lumen extending between opposite ends of the housing and defining at least one accessory mounting rail on an upper surface thereof; and coupling a hand guard mounting assembly to a rear end portion of the housing, the hand guard mounting assembly including: an annular barrel nut interface having a flange extending radially inward at a rear end thereof; the flange defining a forward facing surface comprising at least one tab extending radially inward and conforming in size, shape and location to at least one scallop extending radially inward into a flange located on a front end of the barrel nut; the forward facing surface of the at least one tab having at least one indentation configured to receive a tine extending radially outward from the flange longitudinally therein; and
- FIG 1A is left side elevation view of an example firearm, namely, an M-16 rifle 10, of a type with which embodiments of the novel hand guard of the present disclosure can be advantageously utilized.
- the M16 and a variant thereof, viz., the M4, has generally replaced the M14 and M1 carbine as the standard infantry rifles of the U.S. armed forces.
- the M16 is the most commonly manufactured 5.56x45 mm rifle in the world, and is in use by 15 NATO countries and more than 80 countries worldwide. Numerous companies in the United States, Canada, and China have, together, produced more than 8,000,000 M-16 rifles, in all of its many variants, of which approximately 90% are still in operation.
- the example rifle 10 includes a receiver 12 having a combined carrying handle and rear sight 14, a rear or shoulder stock 16 extending rearwardly from the receiver 12, a pistol-type hand grip 18, a trigger 20 for firing the rifle 10, a magazine 22 for holding ammunition, an elongated barrel 24 extending forwardly from the receiver 12, an upstanding front sight 26 mounted forwardly on the barrel 24, and a longitudinal axis 28 concentric with the barrel 24.
- a gas tube 30 Extending rearwardly from the front sight 26 to the receiver 12 is a gas tube 30 that conveys combustion gases from a port (not seen in Fig. 1A ) in the barrel 24 located below the front sight 26 to the receiver 12, which are used by components in the receiver for the automatic actuation of the rifle 10 when it is fired.
- the example rifle 10 also conventionally includes a hand guard, typically made of a plastic composite, that surrounds the gas tube 30 and an intermediate portion 32 of the barrel 24.
- a hand guard typically made of a plastic composite
- the conventional hand guard has been omitted for purposes of explication.
- the intermediate portion 32 of the barrel 24 includes a pair of front and rear radial surfaces 34 and 36 respectively disposed at opposite ends thereof.
- the front radial surface 34 comprises the rear surface of a hand guard forward support cap 38
- the rear radial surface 36 comprises the front surface of a threaded hand guard rear slip ring retainer 40 (also referred to as a barrel nut).
- the two radial surfaces 34 and 36 disposed at the opposite ends of the intermediate portion 32 of the barrel 24 can, in some embodiments, provide features that are advantageous for mounting a hand guard 100 in accordance with the present disclosure on the rifle 10.
- Fig. 1B is an upper, front, left side perspective view of the receiver 12 and barrel 24 of the rifle 10 of Fig. 1A , showing a first example embodiment of a hand guard 100 in accordance with the present disclosure mounted thereon.
- Figs. 2 and 3 are upper, front, left side perspective and exploded perspective views of the example hand guard 100, respectively.
- the example hand guard 100 comprises an elongated tubular housing 102 having an upper part 104, a lower part 106, opposite open ends 108 and 110, and a lumen 112 configured to receive the gas tube 30 and intermediate portion 32 of the barrel 24 of the firearm 10 longitudinally therein.
- the housing 102 can have a generally polygonal cross-section, and in the particular embodiment illustrated, the housing 102 has eight side walls, i.e ., is octagonal in cross-sectional shape. Other cross-sectional shapes, including round or annular, can also be used. At least one of the side walls of the housing 102 can comprise a longitudinal accessory mounting rail 113, such as specified in MIL-STD-1913 and commonly referred to as a "Picatinny" rail, or other type of rail. In the particular example embodiment illustrated in Fig.
- four such accessory mounting rails 113 are provided, disposed in alternating fashion around the circumfery of the housing 102, one comprising the top side wall of the upper part 104 of the housing 102, and three comprising the two lateral and one bottom side walls of the lower part 106 thereof.
- a top rail 113 on upper part 104 may be substantially level with another rail 170 (e.g., another longitudinal accessory mounting rail such as another Picatinny rail or other type of rail).
- another rail 170 e.g., another longitudinal accessory mounting rail such as another Picatinny rail or other type of rail.
- Such positioning of rails 113 and 170 may advantageously permit various accessories to be mounted substantially in line with each other on rails 113 and 170 and/or permit such accessories to be mounted across both rails 113 and 170 (e.g., using mounting locations of both rails 113 and 170).
- a lighting device 190 e.g., a SureFire Scout Light in one embodiment
- a rail clamp 192 such as a SureFire M93 Swing-Lever WeaponLight Rail Clamp in one embodiment and/or as identified in U.S. Patent No. 8,127,484 ).
- upper part 104 may include one or more protrusions 182 (e.g., one or more flanges or individual protruding members) configured to engage or contact receiver 12 (see Figs. 1B and 3 ).
- protrusion 182 may extend over, rest upon, and/or push against various external portions of retainer 40 and/or of rear sight 14.
- lower part 106 may include one or more protrusions 180 (e.g., implemented as one or more flanges or individual protruding members) configured to engage or contact receiver 12 (see Figs. 1B and 3 ).
- protrusions 180 may rest upon and/or push against retainer 40.
- protrusions 180 and/or flanged portion 182 may be used to further secure hand guard 100 to rifle 10.
- the example hand guard 100 further comprises an expansion collar 114 disposed at one end of the housing 102.
- the expansion collar 114 incorporates an expansion mechanism, described below, configured to adjustably compress the expansion collar 114 and the lower part 106 of the housing 102 longitudinally between the radial surfaces 34 and 36 located at opposite ends of the intermediate portion 32 of the barrel 24, as described above.
- the expansion collar 114 is shown disposed adjacent to the front end 108 of the housing 102, but as those of some skill in the art will appreciate, this arrangement can be reversed, such that the expansion collar 114 is disposed adjacent to the rear end 110 of the housing 102.
- the expansion collar 114 can include a longitudinal tongue 116 that can be slid into a complementary recess in the adjacent open ends 108 or 110 of the housing 102 to generally align the collar 114 concentrically with the housing 102 and the lumen 112 thereof.
- the expansion mechanism can comprise a plurality, e.g., two or more, of longitudinally extending screws 118 (e.g., also referred to as jack screws) respectively received in corresponding ones of a plurality of threaded apertures 120 contained in the expansion collar 114.
- Each screw 118 has a distal end 122 that can be urged into abutment with an adjacent end, 108 or 110 of the lower part 106 of the housing 102.
- the end 108 or 110 of the housing 102, against which the distal ends 122 of the screws 118 bear, can be protected against any resultant deformation and wear caused by abutment of the screw ends 122 by the provision of a corresponding plurality of wear pads 124 made of, e.g., a hard metal, disposed in corresponding, complementary recesses 126 in the adjacent end of the lower part 106 of the housing 102.
- the distal ends 112 of the screws 118 can then respectively bear on the pads 124 with virtually no resulting wear or deformation of the adjacent end of the lower part 106 of the housing.
- the longitudinal expansion of hand guard 100 may cause protrusions 180 to push against retainer 40 and thus tighten end 110 of hand guard 100 against rifle 10.
- the expansion mechanism can further include a plurality of elongated compression members 128 that extend longitudinally from an end of the expansion collar 114 opposite to the end of the housing 102 at which the expansion collar 114 is disposed.
- the compression members 128 can include a first end portion 130 that can comprise a material that may compress and expand (e.g., being at least partially deformable, compressible, and/or expandable) while still remaining relatively resilient, such as rubber or polyurethane, which is disposed in a corresponding bore 132 (see Fig. 7B ) in the expansion collar 114, and an opposite second end 134 comprising a relatively harder bearing material, e.g., a metal, such as steel.
- the example hand guard 100 can be mounted on an associated rifle 10 in accordance with the following example mounting method, in which it is assumed that the expansion collar 114 is mounted at the front end 108 of the housing 102 and disposed adjacent to the front radial surface 34, as illustrated in the example embodiment of Figs. 1A and 1B .
- the upper part of the housing 102 is removed from the lower part 106, which can be effected in a manner described in more detail below.
- the longitudinal tongue 116 of the expansion collar 114 is inserted into the front end 108 of the lower part 106 of the housing 102 to form a loose assembly therewith.
- the assembly of the expansion collar 114 and lower part 106 of the housing 102 is then mounted onto the lower surface of the intermediate portion 32 of the rifle barrel 24 and between the radial surfaces 34 and 36 disposed at the opposite ends thereof, i.e., with the compression members 128 of the expansion collar 114 disposed adjacent to the front radial surface 34 and the rear end 110 of the lower part 106 of the housing 102 disposed adjacent to the rear radial surface 36.
- the assembly of the expansion collar 114 and lower part 106 of the housing may be positioned around (e.g., without touching) the intermediate portion 32 of the rifle barrel 24 and rotated thereabout until the lower part 106 of the housing 102 is disposed beneath the rifle barrel 24.
- the screws 118 are then advanced in their respective threaded apertures 120 in the expansion collar 114 such that the distal end 122 of each screw 118 engages a corresponding pad 124 in the adjacent end of the lower part 106 of the housing 102.
- further advancement of the screws 118 causes the lower part 102 and expansion collar 114 to spread apart from each other, thereby loading the entire longitudinal assembly comprising the compression members 128, the expansion collar 114, and the lower part 106 of the housing 102, in compression between the two radial surfaces 34 and 36, thereby firmly coupling the longitudinal assembly firmly to the rifle 10.
- this compressive force results in a reactive longitudinal tensile force being applied to the barrel 24 of the rifle 10, which, unlike various prior hand guards, does not result in any twisting or local deformations of the barrel 24, and therefore does not adversely affect the accuracy of the rifle 10.
- Any differences in the respective forces exerted by the screws 118 are taken up by the plurality of compression members 128, which compress or expand locally (e.g., performed by the material of first end portion 130) to ensure that the force exerted by the screws 118 is substantially uniformly distributed among the compression members and on the adjacent end of the lower part 106 of the housing 102.
- first end portion 130 of compression members 1208 such material may be provided by any component of hand guard 100.
- such material may be provided as part of screws 118 and/or other components adapted to compress and expand between end 108 and surface 34.
- the upper part 104 of the housing 102 can be removed from the lower part 106 of the housing 102, e.g., to gain access to the gas tube 30 and/or the intermediate portion 32 of the barrel 24, without having to remove the lower part 106 and expansion collar 114 from the rifle 10. As illustrated in, e.g., Figs. 3 and 6 , this can be effected by the provision of a coupling mechanism for releasably coupling the upper part 104 of the housing 102 to the lower part 106 thereof. Moreover, the lower part 106 may remain tightly engaged with surfaces 34 and 36 (e.g., by longitudinal expansion) while the upper part 104 is removed.
- accessories installed onto lower part 106 may remain attached and in alignment while the upper part 104 is removed. Also, accessories installed onto upper part 104 may also remain attached and in alignment while the upper part 104 is removed. Therefore, if upper part 104 is subsequently attached to lower part 106, all accessories attached to hand guard 100 may be aligned and ready for use without requiring further adjustment by the user.
- upper part 104 and/or lower part 106 may be changed.
- the locations of upper part 104 and lower part 106 may be reversed such that upper part 104 is actually positioned below lower part 106 while hand guard 100 is installed on intermediate portion 32 of barrel 24.
- upper part 104 may be lowered downward from rifle 10 (e.g., lowered down on the trigger side of rifle 10) while lower part 106 remains installed (e.g., positioned on a top side of rifle 10 and straddling intermediate portion 32 of barrel 24).
- the upper part 104 of the housing 102 can include a pair of laterally spaced, downwardly extending side walls 138, each having a lower edge 140 and a generally planar exterior surface 142.
- the lower part 106 of the housing 102 can have a pair of laterally spaced, upwardly extending side walls 141, each of which has a generally planar interior surface 144, with a ledge 146 disposed at a lower edge thereof. As illustrated in Fig.
- the side walls 138 of the upper part 104 are positionable inside the side walls 141 of the lower part 106 such that respective ones of the planar exterior surfaces 142 of the side walls 138 of the upper part 104 are disposed in facing opposition to corresponding ones of the planar interior surfaces 144 of the side walls 141 of the lower part 102.
- Figs. As illustrated in, e.g., Figs.
- the coupling mechanism can comprise a plurality of threaded fasteners 148 respectively extending laterally through apertures 150 (e.g., openings) in corresponding ones of the side walls 141 of the lower part 106 of the housing 102 and into corresponding threaded apertures 152 disposed in corresponding ones of the side walls 138 of the upper part 104 of the housing 102, and arranged such that advancement of the fasteners 148 into the threaded apertures 152 acts to pull the planar surfaces 142 of the side walls 138 of the upper part 104 into engagement with corresponding ones of the planar surfaces 144 of the side walls 141 of the lower part 106.
- apertures 150 e.g., openings
- threaded apertures 152 may be provided by side walls 138 of the upper part 104 (e.g., integral therewith). In another embodiment, threaded apertures 152 may be provided by separate components (e.g., nuts or bushings) that are pressed, welded, and/or otherwise attached positioned into apertures 151 of the upper part 104 (e.g., positioned within lumen 112 when hand guard 100 is assembled).
- separate components e.g., nuts or bushings
- the threaded apertures 152 in the side walls 138 of the upper part 104 can be respectively disposed a first distance above the lower edge 140 of the corresponding side wall 138 of the upper part 104, and the apertures 150 in the side walls 141 of the lower part 106 can be respectively disposed a second distance above the ledge 146 of the corresponding side wall 141.
- the first distance can be made slightly greater than the second distance (e.g., greater by a distance of approximately 8 thousandths of an inch in one embodiment), such that advancement of the threaded fasteners 148 into the threaded apertures 152 further acts to pull the lower edges 140 of the side walls 138 of the upper part 104 into a tight engagement with the corresponding ledges 146 of the side walls 141 of the lower part 106, thus ensuring a tight coupling of the upper part 104 to the lower part 106.
- apertures 150 may be implemented with countersinks 155.
- countersinks 155 may be offset downward or otherwise (e.g., by approximately 8 thousandths of an inch in one embodiment) such that upper portions of heads 149 of threaded fasteners 148 contact rail 113 and/or the lower part 106 before threaded fasteners 148 are fully screwed into threaded apertures 152 and fully seated within countersinks 155. Such contact can provide compressive force to further secure upper part 104 and lower part 106 together.
- vent holes 154 serve to reduce the weight of the hand guard substantially, and can also serve both to cool the barrel 24 of the rifle 10 during extended firing thereof, thereby ensuring that the hand guard 100 remains cool to the touch, and also to mount certain types of accessories to the hand guard 100 (e.g., such as lighting device 190 in one embodiment).
- accessories may be mounted directly to vent holes 154 (e.g., without requiring rail clamp 192 or other mounting mechanisms).
- Fig. 10 is an upper left side perspective view of a receiver and barrel of an M4 rifle 10 (e.g., with rear sight 14 removed), showing a second example embodiment of a hand guard 200 in accordance with the present disclosure mounted thereon
- Fig. 11 is an upper, front, right side perspective view of the receiver, barrel and second example hand guard 200 of Fig. 10 , showing an example accessory mounting bracket 201 mounted on the right side thereof.
- the two example hand guards 100 and 200 differ in various ways such as, for example, the mechanisms used to spread the lower part of the hand guard and expansion collar apart from each other so as load the assembly of the expansion collar and the lower part of the housing of the hand guard in compression between the two radial surfaces 34 and 36 of the rifle 10, coupling mechanisms and engagement surfaces, features in the side walls of the hand guard housing that enable various accessory mounting brackets to be coupled to it efficiently and reliably, and other features further discussed herein.
- Figs. 12 and 13 are upper, front, left side perspective and exploded perspective views of the second example hand guard 200, respectively.
- the second example hand guard 200 can, like the first example embodiment 100 above, comprise an elongated tubular housing 202 having an upper part 204, a lower part 206, opposite open ends 208 and 210, and a longitudinal lumen 212 configured to accommodate the gas tube 30 and intermediate portion 32 of the barrel 24 of the rifle 10 longitudinally therein.
- the housing 202 can have a generally polygonal cross-section, and in the particular embodiment illustrated, the housing 202 has eight side walls, i.e., has a cross-sectional shape that is octagonal. Of course, other cross-sectional shapes, including round or annular, can also be used. At least one of the side walls of the housing 202 can comprise an integrally formed, longitudinal accessory mounting rail 213, such as specified in MIL-STD-1913 and commonly referred to as a "Picatinny" rail, or as discussed below, a variation thereof. In the particular example embodiment illustrated in Figs.
- two such integral accessory mounting rails 213 are provided, i.e., one disposed atop the top wall of the upper part 204 of the housing 202, and one disposed on the bottom wall of the lower part 206 thereof.
- a top rail 213 on the upper part 204 can be disposed substantially level with another rail 270 (e.g., another longitudinal accessory mounting rail, such as another Picatinny rail or other type of rail).
- another rail 270 e.g., another longitudinal accessory mounting rail, such as another Picatinny rail or other type of rail.
- Such positioning of the rails 213 and 270 can advantageously enable various accessories to be mounted substantially in line with each other on the rails 213 and 270 and/or enable such accessories to be mounted across both rails 213 and 270 (e.g., using the mounting locations of both rails 213 and 270).
- one or more accessories can be mounted on the rails 213 such as, for example, lighting devices, sighting devices, and/or other types of devices.
- the upper part 204 can include one or more protrusions 282 (e.g., one or more flanges or individual protruding members) configured to engage or overlie a front end portion of the receiver 12 (see, e.g., Figs. 10 - 12 ).
- the protrusion 282 can extend over, rest upon, and/or push against various external portions of the retainer 40.
- the lower part 206 can include one or more protrusions 280 (e.g., implemented as one or more flanges or individual protruding fingers) configured to engage or contact the retainer (e.g., barrel nut) 40 (see, e.g., Figs. 12 and 13 ).
- the protrusions 280 can rest upon and/or push against the retainer 40.
- the protrusions 280 and/or the flanged portion 282 can be used to further secure the hand guard 200 to the rifle 10.
- the second example hand guard 200 also comprises an expansion collar 214 disposed at one end of the housing 202.
- the expansion collar 214 incorporates an expansion mechanism, described in more detail below, that is configured to adjustably compress the expansion collar 214 and the lower part 206 of the housing 202 longitudinally between the radial surfaces 34 and 36 located at opposite ends of the intermediate portion 32 of the barrel 24, as described above.
- the expansion collar 214 is shown disposed adjacent to the front end 208 of the housing 202, but as those of some skill in this art will appreciate, this arrangement can be reversed, such that the expansion collar 214 is disposed adjacent to the rear end 210 of the housing 202.
- the expansion collar 214 can include a pair of longitudinal tongues 216 that can be slid into a complementary recess in the adjacent open ends 208 or 210 of the housing 202 to generally align the collar 214 concentrically with the housing 202 and the lumen 212 thereof.
- the expansion mechanism can comprise a pair of longitudinally extending screws 218 (also referred to herein as jack screws) respectively received in corresponding ones of a pair of threaded apertures 217 respectively contained in a corresponding pair of laterally opposing stanchions 219 respectively attached to the inner surfaces of the side walls 241 of the lower part 206.
- each of the two side wall stanchions 219 is attached to a corresponding side wall 241 of the lower part 206 by a pair of threaded fasteners 221 that extend through corresponding through-apertures in the adjacent side wall 241 and into corresponding threaded apertures in the stanchions 219.
- the stanchions 219 can be coupled or connected to the side walls 241 of the lower part 206 using other methods, such as brazing, welding, staking, riveting, adhesive bonding and so on.
- each of the longitudinal tongues 216 of the expansion collar 214 includes a longitudinal bore 220 having an open side and a bottom end surface 224.
- Each jack screw 218 has a distal end that can be urged into abutment with an corresponding one of the bottom end surfaces 224 of the longitudinal bores 220 by advancing the jack screw 218 in the threaded aperture 217 of the corresponding stanchion 219.
- the resulting longitudinal expansion of the hand guard 200 causes the protrusions 280 to push against the retainer 40 and thereby tighten the end 210 of the hand guard 200 against the forward facing surface 36 of the receiver 12 of the rifle 10.
- the expansion mechanism can further include a plurality of elongated compression members 228 that extend longitudinally from an end of the expansion collar 214 opposite to the end of the housing 202 at which the expansion collar 214 is disposed.
- the compression members 228 can include a first end portion 230 that can comprise a material that can compress and expand (e.g., being at least partially deformable, compressible, and/or expandable) while still remaining relatively resilient, such as a rubber or polyurethane, which is disposed in a corresponding bore 232 (see, e.g., Fig. 17B ) in the expansion collar 214, and an opposite second end 234 that can comprise a relatively harder bearing material, e.g., a metal, such as steel or aluminum.
- a relatively harder bearing material e.g., a metal, such as steel or aluminum.
- the second example hand guard 200 can be mounted on an associated rifle 10 in accordance with the following example mounting method, in which it is assumed that the expansion collar 214 is mounted at the front end 208 of the housing 202 and disposed adjacent to the front radial surface 34 of the rifle 10, as illustrated in the example embodiment of Figs. 10 and 11 . However, as discussed above, this orientation can be reversed, if desired.
- the upper part 204 of the housing 202 is removed from the lower part 206, which can be effected in a manner described in more detail below.
- the longitudinal tongues 216 of the expansion collar 214 are inserted into the front end 208 of the lower part 206 of the housing 202 to form a loose assembly therewith.
- the assembly of the expansion collar 214 and lower part 206 of the housing 202 is then mounted onto the lower surface of the intermediate portion 32 of the rifle barrel 24 and between the radial surfaces 34 and 36 disposed at the opposite ends thereof, i.e., with the compression members 228 of the expansion collar 214 disposed adjacent to the rear-facing front surface 34 and the rear end 210 of the lower part 206 of the housing 202 disposed adjacent to the front-facing rear surface 36.
- the assembly of the expansion collar 214 and lower part 206 of the housing 202 can be positioned around (e.g., without touching) the intermediate portion 32 of the rifle barrel 24 and rotated thereabout until the lower part 206 of the housing 202 is disposed below the rifle barrel 24.
- the screws 218 are then advanced in their respective threaded apertures 217 in the stanchions 219 such that the distal end of each screw 218 is disposed in abutment with corresponding one of the bottom end surfaces 224 of the longitudinal bores 220 in the tongues 216 of the expansion collar 214. As indicated by the arrows 236 in Figs.
- this compressive force results in a reactive longitudinal tensile force being applied to the barrel 24 of the rifle 10, which, unlike various prior hand guards, does not result in any twisting or local deformations of the rifle barrel 24, and therefore, does not adversely affect the accuracy of the rifle 10.
- Any differences in the respective forces exerted by the screws 218 are taken up by the plurality of compression members 228, which compress or expand locally (e.g., effected by the resilient material of first end portion 230) to ensure that the force exerted by the screws 218 is substantially uniformly distributed among the compression members 228 and on the adjacent end of the bottom part 206 of the housing 202.
- this function may be effected by, for example, a spring comprising a part of the jack screws 218 and/or other components adapted to compress and expand between the end 208 of the lower part 206 of the housing 202 and the rear-facing radial surface 34.
- the upper part 104 or 204 of the housing 102 or 202 can be removed from the lower part 106 or 206 of the housing 102 or 202, e.g., to gain access to the gas tube 30 and/or the intermediate portion 32 of the barrel 24, without having to remove the lower part 106 or 206 and the expansion collar 114 or 214 from the rifle 10.
- this can be effected in the case of the second example hand guard 200 by the provision of a coupling mechanism for releasably coupling the upper part 204 of the housing 202 to the lower part 206 thereof.
- the lower part 206 can remain tightly engaged with surfaces 34 and 36 (e.g., by longitudinal expansion) while the upper part 204 is removed.
- accessories installed on the lower part 206 can remain attached and in alignment with the rifle 10 while the upper part 204 is removed.
- any accessories installed onto the upper part 204 can also remain attached and in alignment with the upper part 204 when the upper part 204 is removed.
- all accessories attached to the hand guard 200, whether mounted on the upper part 204 or the lower part 206 will remain aligned and ready for use without requiring further adjustment by the user.
- the locations and/or configurations of the upper part 204 and/or lower part 206 can be changed.
- the locations of the upper part 204 and lower part 206 can be reversed such that upper part 204 is actually positioned below the lower part 206 while hand guard 200 is installed on intermediate portion 32 of barrel 24.
- the upper part 204 can be lowered downward from rifle 10 (e.g., lowered down to the trigger side of rifle 10) while lower part 206 remains installed (e.g., positioned on a top side of the rifle 10 and straddling the intermediate portion 32 of the barrel 24).
- upper part 104/204 may be omitted while lower part 106/206 is positioned on a bottom side of the rifle 10 (e.g., to permit installation of any desired apparatus in place of upper part 104/204 above barrel 24).
- upper part 104/204 may also permit the user to gain access to barrel 24, gas tube 30 (e.g., in some embodiments, gas tube 30 may not be accessible while upper part 104/204 is removed), and/or other portions of rifle 10 while lower part 106/206 remains installed in a position on a bottom side or top side of rifle 10.
- the upper part 204 of the housing 202 can include a pair of laterally spaced, downwardly extending lateral side walls 238, and inclined side walls 239 (e.g., inclined approximately 45 degrees relative to side walls 238).
- Each of side walls 238 include a generally planar exterior surface 242 and a flange 243 (e.g., a downwardly projecting engagement surface extending over lateral side walls 238).
- a flange 243 e.g., a downwardly projecting engagement surface extending over lateral side walls 238).
- the lower part 206 of the housing 202 can have a pair of laterally spaced, upwardly extending lateral side walls 241, and inclined side walls 247 (e.g., inclined approximately 45 degrees relative to side walls 241).
- Each of side walls 241 has a generally planar interior surface 244 and also an upper edge 245 (e.g., an upwardly projecting engagement surface at the intersection of angulated faces 255A-B).
- the side walls 238 of the upper part 204 are positionable inside the side walls 241 of the lower part 206 such that respective ones of the planar exterior surfaces 242 of the side walls 238 of the upper part 204 are disposed in facing opposition to corresponding ones of the planar interior surfaces 244 of the side walls 241 of the lower part 206.
- flange 243 of upper part 204 may be brought into contact with upper edge 245 of lower part 206.
- the coupling mechanism can comprise a plurality of threaded fasteners 248 respectively extending laterally through apertures 250 in corresponding ones of the side walls 241 of the lower part 206 of the housing 202 and into corresponding threaded apertures 252 disposed in corresponding ones of the side walls 238 of the upper part 204 of the housing 202, and arranged such that advancement of the fasteners 248 into the threaded apertures 252 acts to pull the planar surfaces 242 of the side walls 238 of the upper part 204 into engagement with corresponding ones of the planar surfaces 244 of the side walls 241 of the lower part 206.
- the threaded apertures 152 can be provided in the side walls 238 of the upper part 204 (e.g., integral therewith).
- the threaded apertures 252 can be provided by separate components (e.g., nuts or bushings) that are pressed, welded, and/or otherwise attached positioned into corresponding apertures in the upper part 204 (e.g., positioned within the lumen 212 when the hand guard 200 is assembled).
- the threaded apertures 252 in the side walls 238 of the upper part 204 can be disposed such that they are slightly higher (e.g., offset by a distance of 8 thousandths of an inch in one embodiment) than the apertures 250 in the side walls 241 of the lower part 206 when upper part 204 is inserted into lower part 206 (e.g., when flanges 243 of upper part 204 are in contact with upper edges 245 of lower part 206 but before upper part 204 and lower part 206 have been secured together).
- the offset between apertures 250 and 252 causes flanges 243 of the side walls 238 of the upper part 204 to be pulled into a tight engagement with the upper edges 245 of the side walls 241 of the lower part 206, thus ensuring a tight coupling of the upper part 204 to the lower part 206.
- the apertures 250 can be implemented with frustoconical countersinks.
- the countersinks can be offset downward or otherwise (e.g., by approximately 8 thousandths of an inch in one embodiment) such that the upper portions of the heads of the threaded fasteners 248 contact the rail 213 and/or the lower part 206 before the threaded fasteners 248 are fully screwed into the threaded apertures 252 and fully seated within the corresponding countersinks. Such contact can provide compressive force to further secure the upper part 204 and the lower part 206 together.
- selected ones or all of the side walls of the housing 102 can include a pattern of apertures 251 (e.g., in upper part 204) and 259 (e.g., in lower part 206). Apertures 251 and 259 reduce the weight of the second example hand guard 200 substantially, and also permit cooling of the barrel 24 of the rifle 10 during extended firing thereof, thereby ensuring that the hand guard 200 remains cool to the touch.
- apertures 251 and 259 may be used to implement elongated slots 254A-B to define rails 289 which may be used to mount accessories to the hand guard 200, e.g., such as, for example, rails 262 illustrated in Figs. 10 , 19A, and 19B , the accessory mounting bracket 201 illustrated in Fig. 11 , and/or other accessories.
- slots 254A may be defined by apertures 251 in inclined side walls 239 of upper part 204 and upper edge 245 of lower part 206.
- slots 254B may be defined entirely by apertures 259 in inclined side walls 247 of lower part 206.
- Figs. 19A - 19C are cross-sectional views of the second example hand guard 200, as seen along the lines of the section 16 - 16 taken in Fig. 12 , showing various accessory and accessory bracket mounting features.
- at least one of the side walls of the housing 202 can comprise an integral, longitudinal accessory mounting rail 213, such as specified in MIL-STD-1913 and commonly referred to as a "Picatinny" rail.
- the housing 202 includes two such integral accessory mounting rails 213, viz., one disposed atop the top wall of the upper part 204 of the housing 202, and one disposed on the bottom wall of the lower part 206 of the housing 202.
- each side of rails 213 include two angulated faces 253A-B (see Figs. 19A-C ) which subtend an angle ⁇ of about 90 degrees, and the width w between the respective intersection of the angulated faces 253A-B on either side of each rail 213 is about 0.835 inches.
- Additional side rails 289 may be provided with "Picatinny rail” features, but having a substantially reduced height relative to conventional Picatinny rails 213 (e.g., without the "neck” portion 256 of the conventional Picatinny rail 213).
- rails 289 include angulated faces 255A-B and 255C-D provided on opposite sides of lateral side walls 241 and proximate to slots 254A-B.
- Slots 254A (e.g., having perimeters defined by apertures 251 in inclined side walls 239 of upper part 204 and upper edge 245 of lower part 206 as discussed) define angulated faces 255A (e.g., interior facing angulated faces corresponding to portions of upper edge 245 of lower part 206).
- Slots 254B (e.g., having perimeters defined by apertures 259 in inclined side walls 247 of lower part 206 as discussed) define angulated faces 255C (e.g., interior facing angulated faces).
- External surfaces of lateral side walls 241 may provide angulated faces 255B and 255D (e.g., exterior facing angulated faces).
- Angulated faces 255A-B and 255C-D of rails 289 may exhibit the same angle ⁇ and the same width w as described for angulated faces 253A-B of rails 213.
- the respective outer surfaces 291 of rails 289 are generally coplanar with the respective outer surfaces of the side walls 241 of the lower part 206.
- the "neck" portion 256 of the conventional Picatinny rail 213 is eliminated in rails 289, resulting in a lighter, narrower, easier-to-grip hand guard 200 without any sacrifice in accessory mounting capabilities.
- Fig. 18A is an upper, front, left side perspective view of the example accessory mounting bracket 201 shown in Fig. 11
- Fig. 18B is an upper, front, right side perspective view thereof.
- the bracket 201 can be configured to mount, for example, a light 190 discussed above in connection with Fig. 3 .
- the mounting bracket 201 can comprise two pairs of fingers 258A and 258B configured to engage a Picatinny rail.
- the pair of fingers 258A can be fixed on the bracket 201 and the other pair of fingers 258B can be arranged to pivot toward and away from the fixed pair 258A, for example, by depressing the head of an actuating member 260 of the type illustrated in Fig. 18B .
- this arrangement enables the mounting bracket 201 to be clamped to a side wall (e.g., as fingers 258A-B extend through slots 254 and around side wall 241) of the housing 202 using the "reduced-height" Picatinny rail design discussed above.
- conventional Picatinny accessory mounting rails 262 can be mounted on the outer surfaces of the side walls of the upper and/or lower parts 204 and 206 of the hand guard housing 202 (e.g., mounted on rails 289, using apertures 251 of upper part 204, using apertures 259 of lower part 206, using apertures 261 in lateral side walls 241, and/or others). As illustrated in the figures, these can be mounted to corresponding ones of the side walls using, for example, threaded fasteners 264 (e.g., see Figs. 19B-C ), but it should be understood that they can also be mounted to the housing 202 using other fastening techniques, such as riveting, adhesive bonding and the like.
- FIG. 21 illustrates side walls 241 of lower part 206 .
- Recesses 207 may be used to position various types of accessories, such as clamp mounts and/or other devices, on hand guard 200.
- Fig. 21 illustrates a lighting device 290 (e.g., a SureFire Scout Light in one embodiment) attached to a clamp mount 292.
- Clamp mount 292 is more clearly shown in the assembled view of Fig. 22 and the exploded view of Fig. 23 .
- Clamp mount 292 may include a bolt 293, a first clamp member 294, a roll pin 295, a second clamp member 296, a washer 297, a split lock washer 298, and a nut 299.
- Clamp mount 292 may be installed on a side wall 241 using slots 254 in a similar manner as described with regard to mounting bracket 201. For example, rotation of nut 299 may cause first and second clamp members 294 and 296 to be pulled toward each other to cause at least a flange 296A of second clamp member 296 to extend around side wall 241.
- Recesses 207 in side walls 241 may be configured (e.g., having substantially scalloped and/or rounded interior surfaces complimentary to shank 293A) to receive shank 294A while clamp mount 292 is installed. Such engagement of a recess 207 with shank 294A permits clamp mount 292 to be conveniently and rapidly positioned at one or more predetermined positions along (e.g., relative to) side wall 241. Other configurations of recesses 207 and clamp mounts 292 may be used where appropriate.
- FIG. 24 A third example embodiment of a hand guard 300 and associated hand guard mounting assembly 302 in accordance with the present disclosure are illustrated in the upper, front and left side perspective view of Fig. 24 , wherein a receiver and rear stock of an associated firearm are omitted for purposes of illustration.
- Fig. 25 is an upper, front, left side perspective view of the third example hand guard 300 of Fig. 24 , in which the mounting assembly 302, the barrel 24 and slip ring 40/328 of the associated firearm, and an accessory mounting rail 304 coupled to a front end portion of a side wall of the hand guard 300 have been omitted for purposes of illustration.
- Figs. 26A - 26E are top plan, front end elevation, left side elevation, rear end elevation, and bottom plan views of the third example hand guard 300, respectively.
- the third example hand guard 300 includes many of the same features present in the first and second example hand guards 100 and 200 described above, in that it comprises an elongated tubular housing 306 having open front and rear ends 308 and 310, a central lumen extending between the two ends, and includes an upper surface that comprises an elongated accessory mounting rail 312.
- the mounting rail 312 can include a rearwardly extending "tail piece" or protrusion 314 that overlies a front portion the receiver (not illustrated) of the associated firearm and forms an continuation of a similar mounting rail disposed on the upper surface of the receiver, as illustrated in the example embodiment of, e.g., Fig. 10 .
- the tubular housing 306 can, in one embodiment, comprise a single piece that is fabricated, for example, as an extrusion of, e.g., an aluminum alloy, e.g., 6061, that is subsequently machined to form such accessory mounting features as transverse lands 316, grooves 318, and various through-apertures 320 of desired shapes and sizes. It can then, for example, be hard anodized otherwise finished or coated to provide robust corrosion protection.
- the tubular housing 306 can be polygonal in cross-section, e.g ., octagonal, so as to provide a plurality of generally flat side walls for the mounting of a variety of firearm accessories, or as illustrated in Fig. 24 , an accessory mounting rail 304, such as a Picatinny rail, upon which an accessory, e.g., a light, a telescopic sight, or the like can be mounted.
- the tubular housing 306 can comprise two or more components that are assembled together during manufacture (e.g., welded together), or assembled together with, e.g ., fasteners, to form the tubular structure 306, such as the first and second hand guards 100 and 200 discussed above and illustrated in, e.g., Figs. 6 and 16 , respectively.
- housing 306 includes various apertures 309 and 311 of differing sizes on 7 sides of the octagonal shape of housing 306, and further includes recesses 307 and rail 312.
- housing 306 includes various apertures 309 and 311 of differing sizes on 7 sides of the octagonal shape of housing 306, and further includes recesses 307 and rail 312.
- a variety of accessories and/or additional rails may be mounted to housing 306 using apertures 309, apertures 311, recesses 307, and/or rail 312 in many convenient and flexible orientations (e.g., around the entire perimeter of housing 306), for example, in accordance with the various techniques described herein.
- the third example hand guard 300 is coupled to the associated firearm in a manner that differs from the first and second hand guards 100 and 200 described above.
- hand guard 300 is mounted using the hand guard mounting assembly 302.
- the mounting assembly 302 couples to a rear end portion of the tubular housing 306 of the hand guard 300.
- the third example hand guard 300 is cantilevered forwardly from a front end of the receiver of the associated firearm (not illustrated) by the mounting assembly 302, and through the agency of a barrel nut 326 of the firearm discussed below, such that the barrel 24 of the firearm is disposed concentrically within the lumen of the tubular housing 306 and such that no contact is made between the housing 306 and the barrel 24.
- This type of mounting is particularly advantageous in that, since no contact of any kind is made between the barrel 24 and the tubular housing 306 of the hand guard 300, the hand guard 300 cannot exert any undesirable bending or torsional stresses on the barrel 24 which could adversely affect the accuracy of the firearm.
- the hand guard 300 is permitted to surround and "float" proximate to the barrel 24.
- the hand guard 300 receives external forces (e.g., when pushed upwardly at the front end while supported from the ground or a structure), such forces will not bias the barrel 24, and sighting accuracy can be maintained.
- thermal expansion of the firearm will not cause the hand guard 300 to shift, thus maintaining the accuracy of aiming devices attached to the hand guard 300.
- Fig. 27 is an enlarged partial cross-sectional view of the third example hand guard 300 and the mounting assembly 302 therefor in accordance with the present disclosure, as seen along the lines of the section 27 - 27 taken in Fig. 24 .
- the mounting assembly 302 comprises an annular barrel nut interface 322 and a wedge ring 324, which are both illustrated in more detail in Figs. 35A - 35D and 36A - 36D , respectively. Also seen in Fig.
- a barrel nut 326 and a slip ring 328 e.g., also referred to as a "D ring” or “Delta ring”, which in some embodiments may be similar to slip ring 40 discussed here
- the slip ring 328 is biased forwardly on the barrel nut 326 and relative to the receiver of the firearm by a slip-ring spring 330, which is disposed concentrically within the slip ring 328 and about the barrel nut 326 and retained in place by a snap ring 332, illustrated in Fig. 40 .
- the mounting assembly 302 couples concentrically to a rear end portion of the tubular housing 306, which is effected through a plurality of threaded fasteners 334, each of which extends radially inward through corresponding through-holes in the barrel nut interface 322 engages in corresponding threaded receptacles 336, e.g ., swage nuts, retained in the tubular housing 306.
- fasteners 334 reduces the likelihood of them becoming loose during repeated or sustained weapon fire (e.g., in contrast to certain prior longitudinally-secured hand guards which may be susceptible to loosening in response to repeated forward and rearward movement of the weapon during firing).
- three fasteners 334 and corresponding receptacles 336 are used to couple the mounting assembly to the tubular housing 306.
- the hand guard mounting assembly 302 may attach to the receiver of the host firearm first, and then the tubular housing 306 may attach to the mounting assembly 302, or alternatively, the mounting assembly 302 may attach to the tubular housing 306 first, then the mounting assembly 302 may attach to the receiver of the host firearm, whichever is more convenient.
- Fig. 37A is an upper and left side perspective view of the barrel nut 326 utilized in the host firearm and with which the example tubular housing 306 and hand guard mounting assembly 302 interface.
- Fig. 37B is a front end elevation view of the barrel nut 326
- Fig. 37C is a left side elevation view thereof
- Fig. 37D is a rear end elevation view thereof.
- the barrel nut 326 comprises an elongated, annular barrel portion 333, which is internally threaded to receive complementary external threads on the host firearm, and a flange 335 that extends radially outward disposed on a front end thereof.
- a flange 335 that extends radially outward disposed on a front end thereof.
- the flange 335 includes a front face 338, a rear face 340, a plurality of teeth (e.g., tines) 342 extending radially outward from it, and a plurality of arcuate scallops 344 (e.g., also referred to as key ways) extending radially into it and alternating with respective ones of the tines 342.
- a circumferential channel 346 within which the snap ring 332 that retains the slip ring spring 330 is installed.
- the radial tines 342 and scallops 344 are arranged in a rotationally symmetrical fashion about a centerline of the flange 335 and barrel nut 326, and hence about the centerline of the barrel 24.
- gas operated firearms of the types contemplated herein employ a gas tube 30 (shown in dashed outline in, e.g., Figs. 30, 31 ) that conveys combustion gases from a port in the barrel 24 located in a distal portion of the barrel 24 to the receiver of the firearm, which are used by components in the receiver for the automatic actuation of the firearm when it is fired.
- the gas tube 30, like the barrel 24 and barrel nut 326, extends forwardly from the center of the receiver at a 12 o'clock position, i.e., disposed above the centerline of barrel of the firearm.
- the scallops 344 in the flange 335 of the barrel nut 326 are semicircular and have a diameter about the same as the gas tube 30.
- the gas tube 30 can be used as an "index" to orient the rotational position of the barrel nut 326 and the barrel 24 of the firearm relative to its receiver by installing the barrel nut 326 such that the gas tube 30 nests radially within one of the scallops 344 of the flange 335.
- a vertical or sagittal plane 348 through the centerline of the barrel 24 bisects the gas tube 30, the barrel 24, the barrel nut interface 322, the wedge nut 324, the barrel nut 326, and the tubular housing 306. Additionally, it should be noted that each of the foregoing structures are disposed concentric to the centerline of the barrel 24 in some embodiments.
- Fig. 35A is an upper and left side perspective view of a barrel nut interface 322 of the example hand guard mounting assembly 302.
- Fig. 35B is a front end elevation view of the barrel nut interface 322
- Fig. 35C is a left side elevation view thereof
- Fig. 35D is a rear end elevation view thereof.
- the barrel nut interface 322 comprises a generally annular structure having a flange 350 extending radially inward at a rear end 352 thereof.
- the internal flange 350 of the barrel nut interface 322 defines a forward facing transverse surface comprising a plurality of substantially semicircular tabs 354 extending radially inward and substantially conforming in size, shape, and location to the scallops 344 of the barrel nut 326.
- selected ones of these tabs 354 include indentations 356 formed in the forward facing surface of the tabs 354.
- the indentations 356 are configured to receive a corresponding one of the tines 342 on the flange 335 of the barrel nut 326 longitudinally, i.e., in a front-to-rear direction, in a manner described in more detail below.
- the number of indentations 356 and/or the number of tabs 354 can be varied, including up to one indentation 356 per tab 354.
- the flange 350 at the rear of the barrel nut interface 322 includes a cutout 358 configured to clear the gas tube 30 extending forwardly from the receiver at the 12 o'clock position thereon. Additionally, as can be seen in, e.g., Figs.
- the barrel nut interface 322 includes four circumferentially distributed, radially extending threaded receptacles 360, each of which is configured to receive a corresponding one of four set screws 374, which, as described in more detail below, are used both to retain the wedge ring 324 concentrically within the barrel nut interface 322 and to advance the wedge nut 324 longitudinally toward the forward facing surface of the flange 350 of the barrel nut interface 322. Similar to fasteners 334, the radial orientation of set screws 374 reduces the likelihood of them becoming loose during repeated or sustained weapon fire.
- Fig. 36A is an upper and left side perspective view of the wedge ring 324 of the example mounting assembly 302.
- Fig. 36B is a front end elevation view of the example wedge ring 324
- Fig. 36C is a left side elevation view thereof
- Fig. 36D is a rear end elevation view thereof.
- the wedge ring 324 comprises a generally annular structure that includes a central bore through which the barrel 24 of the host firearm extends and an arcuate space 362 in its circumfery that, like the cutout 358 in the flange 350 of the barrel nut interface 322, is adapted to clear the gas tube 30 when the wedge ring 324 is disposed in its operating position.
- the wedge ring 324 includes a rearward facing transverse surface 364 having a plurality of rearwardly extending lands 366 disposed thereon, each substantially conforming in size, shape and location to one of the scallops 344 in the flange 335 of the barrel nut 326.
- lands 366 there are four rearwardly extending lands 366 disposed in a bilaterally symmetrical relationship relative to a sagittal plane of the wedge ring 324, but as in the case of the indentations 356 in the flange 350 of the barrel nut interface 322, the number and angular positions of the lands 366 can be varied within limits, such that they substantially align with a corresponding one of the scallops 344 in the flange 335 of the barrel nut 326 when the wedge ring 324 is disposed in its clamping position described below.
- the wedge ring 324 includes a plurality, e.g., four, L-shaped mounting and clamping adjustment features 368 extending forwardly from a front surface thereof.
- Each L-shaped feature 368 comprises a plane 370 that is inclined relative to both the longitudinal and radial directions and a radially extending leg 372 disposed forwardly of the inclined plane 370. As illustrated in, e.g., Fig.
- the inclined plane 370 and radial leg 372 act in cooperation with a corresponding set screw 374 extending in a radial direction through a corresponding one of the four threaded receptacles 360 in the sides of the barrel nut interface 322 described above to: retain the wedge ring 324 concentrically within the barrel nut interface 322 and; when the set screws 374 are advanced radially inward against corresponding ones of the inclined planes 370, to urge the rearward facing transverse surface 364 of the wedge ring 324 rearwardly, in the direction of the arrow 377 in Fig.
- the set screws 374 in the barrel nut interface 322 can be backed out of their receptacles 360 until the body of the wedge ring 324 and the tops of the radial legs 372 clear the ends of the set screws 374.
- the wedge ring 324 can then be inserted longitudinally forward in the barrel nut interface 322 such that the wedge ring 324 is disposed generally concentrically within the barrel nut interface 322, the arcuate space 362 in the circumfery of the wedge ring 324 is generally aligned with cutout 358 the gas tube 30 in the rear end of the barrel nut interface 322 and each of the inclined planes 370 is disposed below a corresponding one of the set screws 374.
- the set screws 374 can then be advanced radially within their respective receptacles 360 in the barrel nut interface 322 until their ends contact a corresponding one of the inclined planes 370, at which point the wedge ring 324 is retained concentrically within the barrel nut interface 322 and the hand guard mounting assembly 302 is prepared for assembly to the host firearm.
- a slip ring 328 of a type employed on the host firearms contemplated herein is illustrated in the upper and left side perspective view of Fig. 38A.
- Fig. 38B is a front end elevation view of the slip ring 328
- Fig. 38C is a left side elevation view thereof
- Fig. 38D is a rear end elevation view thereof.
- the slip ring 328 comprises an annular, generally frusto-conical structure having a stepped circumferential surface. As can be seen in, e.g., Figs.
- the slip ring 328 includes a notch 329 similar to the cutout 358 in the rear end of the barrel nut interface 322 and the arcuate space 362 in the circumfery of the wedge ring 324 that is configured to clear the gas tube 30 (shown in dashed outline) extending forwardly from the receiver of the host firearm.
- the slip ring spring 330 used to bias the slip ring 328 forwardly on the barrel nut 326 is illustrated in the upper and left front perspective, left side elevation, rear end views thereof of Figs. 39A - 39C , respectively, and Fig. 40 is a front end elevation view of a snap ring 332 used to retain the slip ring spring 330 on the barrel nut 326 and behind a flange at the front end of the slip ring 328.
- the hand guard mounting assembly 302 is coupled to a rear end portion of the housing 306, using, e.g., a plurality of radially extending fasteners 334 (e.g., extending radially inward toward the barrel 24 of the firearm) of the type described herein.
- a distal end of the barrel 24 of the firearm is then inserted through the rear end of the mounting assembly 302 and into the lumen of the tubular housing 306 such that the rear end 352 of the barrel nut interface 322 is disposed in flush abutment with a front end of the slip ring 328 of the firearm (see Figs. 27 and 33 ), the barrel 24 is disposed concentrically within the lumen of the housing 303, and the gas tube 30 of the firearm is disposed within the cutout 358 in the rear end 352 of the barrel nut interface 322 and the arcuate space 362 in the circumfery of the wedge nut 324.
- the mounting assembly 302 is then advanced longitudinally rearward against the slip ring 328 and the bias of the slip ring spring 330 such that the tabs 354 of the barrel nut interface 322 pass through respective ones of the scallops 344 of the flange 335 of the barrel nut 326, the rear face 340 of the flange 335 on the barrel nut 326 is disposed forward of the forward facing surface of the tabs 354 on the barrel nut interface 322, and the front face 338 of the flange 335 is disposed rearward of the rearward facing surface 364 of the wedge ring 324.
- the mounting assembly 302 is the rotated circumferentially relative to the receiver of the firearm (e.g., rotated around the barrel 24) until the accessory mounting rail 312 on the upper surface of the tubular housing 306 is aligned substantially perpendicular to a sagittal plane 348 extending through a centerline of the barrel 24 of the firearm, the tines 342 on the flange 335 of the barrel nut 326 are aligned radially with corresponding ones of the indentations 356 in the forward facing surfaces of the tabs 354 of the barrel nut interface 322, and lands 366 on the rearwardly facing surface 364 of the wedge ring 324 are aligned radially with corresponding ones of the scallops 344 in the flange 335 of the barrel nut 326.
- Fig. 34 illustrates barrel nut interface 322, wedge ring 324, and barrel nut 326 in a locked position.
- the set screws 374 in the barrel nut interface 322 can then be tightened in a radially inward direction and against corresponding ones of the inclined planes 370 of the wedge ring 324, thereby clamping the flange 335 of the barrel nut 326 firmly between the rearward facing surface 364 of the wedge ring and the forward facing surfaces of tabs 354 of the barrel nut interface 322.
- the hand guard 300 is cantilevered forwardly from the front of the receiver of the firearm, with the barrel 24 disposed concentrically within the lumen of the tubular housing 306, and as discussed above, is prevented from moving, either longitudinally or rotationally relative to the barrel 24 or receiver.
- the tubular housing 306 can provide one or more generally flat side walls for the mounting of a variety of firearm accessories, or as illustrated in Fig. 24 , an accessory mounting rail 304, such as a Picatinny rail, upon which a firearm accessory, e.g., a light, a telescopic sight, or the like can be mounted.
- Fig. 41 is a partial top plan view of accessory mounting rail 304 shown mounted to the example hand guard 306 of Fig. 24 in accordance with the present disclosure, as seen along the lines of the section 41 - 41 taken therein.
- Fig. 42A is a top plan view of the example accessory mounting rail 304
- Fig. 42B is a left side elevation view thereof
- Fig. 42C is a bottom plan view thereof
- Fig. 42D is a right side elevation view thereof.
- the example accessory mounting rail 304 comprises an elongated body 381, which in one embodiment, can comprise an extrusion, that is coupled to the associated tubular housing 306 by means of a pair of fasteners 382 (e.g., quarter turn or half turn fasteners in some embodiments) that extend into corresponding apertures 320 in the housing 306.
- a pair of fasteners 382 e.g., quarter turn or half turn fasteners in some embodiments
- Fig. 43A is a cross-sectional view of the accessory mounting rail 304 and an example fastener 382 used to fasten it to the example hand guard 300, as seen along the lines of the section 43 -43 taken in Fig. 42C .
- Fig. 43B is a cross-sectional view of the accessory mounting rail 304 and the example fastener 382, as seen along the lines of the section 43 -43 taken in Fig. 42C while the accessory mounting rail is attached to the housing 306 of hand guard 300.
- Fig. 44A is a top plan view of the fastener 382
- Fig. 44B is a left side elevation view thereof
- Fig. 44C is a bottom plan view thereof.
- the fastener 382 comprises a shaft 383 rotatably retained within a bore extending through the body 381 of the accessory mounting rail 304. As illustrated in Figs. 42D and 43 , each shaft 383 can be rotatably retained in the body 381 of the rail 304 by a set screw 384 having a ball bearing 385 rollably disposed at an internal end thereof to permit easy rotation of the shaft 383 within its associated bore.
- the fastener 382 is provided with a head 386 formed at a proximal end of the shaft 383, and the head 386 includes a recess 387 configured to receive a tool for turning the shaft 383.
- the recess 387 comprises a narrow slot having an arcuate bottom that is adapted to receive the edge of a coin, such as a dime, penny, nickel, and/or quarter, and/or a screwdriver.
- An oval shaped foot 388 is fixed against rotation relative to the shaft 383 at a proximal end thereof by, e.g., a roll pin 390.
- the installation of the rail 380 on the tubular housing 306 of the hand guard 300 involves aligning the long dimension of the heads 386 and the oval feet 388 of the fasteners 382 along the long dimension of the body 381.
- the rail 304 is placed at the desired longitudinal position on a flat surface of the tubular housing 306 and respective ones of the oval feet 388 of the fasteners 382 are inserted through corresponding apertures 320 in the housing 306.
- the heads 386 of the fasteners 382 are then turned until the heads 382, and hence the oval feet 388 of the fasteners are disposed perpendicular to the long axis of the body 381, and the upper surfaces of the oval feet 388 are engaged with the inner wall surfaces of the housing 306.
- a Belleville disk spring 391 may be provided to bias the fastener 382 outward (e.g., by pushing head 386 downward against an inside surface 305 of housing 306 in Fig. 43B ), to clamp on to housing 306.
- Fig. 45 is an upper, front, left side perspective view of another example hand guard 400 of a type similar to that of Fig. 24 , in accordance with the present disclosure.
- the example hand guard 400 includes many of the same features and mounting capabilities as the third example hand guard 300 described above, except that it has a housing 406 that is shorter in length than housing 306, and therefore adapted to firearms having shorter barrels 24, e.g., an M4 carbine rifle.
- the various hand guards of the present disclosure may be modified as appropriate for use with various types and lengths of weapons.
- any of the various features set forth in the present disclosure (e.g., with regard to the various hand guards and mounting hardware) may be combined with each other, in whole or in part, as may be desired for various applications.
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- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Aiming, Guidance, Guns With A Light Source, Armor, Camouflage, And Targets (AREA)
Description
- This invention relates to firearms in general, and in particular, to hand guards for firearms that enable various accessories to be mounted thereon reliably and efficiently.
- Firearms, such as the M16 and M4 rifles adopted for use by the U.S. military services, typically incorporate a hand guard made of a plastic or composite material, by which the shooter can effectively grasp a forward portion of the barrel of the weapon, e.g., for carrying, aiming and shooting the weapon effectively. Additionally, it is recognized that such firearms can often benefit from a variety of shooting accessories coupled to the weapon, such as lights for illuminating targets or sighting devices, e.g., laser targeting devices. Responsively, the prior art is replete with examples of devices, including hand guards adapted to replace the stock hand guard provided on the rifle, that are designed to enable one or more accessories to be coupled to the weapon.
- However, these prior art devices and hand guards are not free of problems. For example, some rely on complicated mechanisms for coupling the hand guards to the rifle that can result in an unreliable mounting of the hand guard on the rifle, typically accompanied by a lengthy amount of time needed to mount the hand guard on the weapon. In other instances in which the hand guard mounts on the barrel of the rifle, the forces applied to the barrel in mounting the hand guard to it can twist or deform the barrel such that the accuracy of the rifle is adversely affected.
- Accordingly, a need exists for hand guard designs that enable a variety of useful accessories to be mounted on a firearm, together with methods for mounting the hand guards on the firearm quickly, reliably and without adversely affecting their accuracy.
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EP 2653823 describes a hand guard including an elongated tubular housing comprising an upper part, a lower part and a lumen configured to substantially surround an intermediate portion of a barrel of a firearm. Each of the lower and upper part being provided with at least one rail adapted to receive an accessory to be mounted thereon. The rail may be a reduced-height Picatinny rail provided by the lateral side wall of the housing. -
US 2011061281 describes a hand guard rail system fastened to a firearm having a barrel and a barrel nut, with the hand guard rail aligned to the top rail of the firearm. The hand guard rail system includes a hand guard and a sleeve fitted into the hand guard. The sleeve and the hand guard are fastened to the barrel nut, thereby aligning the hand guard to the firearm. -
WO 2009082520 describes installing a hand guard on a firearm. The firearm includes a barrel, a barrel nut, and a delta ring. The delta ring is retracted away from the barrel nut. A number of hand guard members are positioned about the barrel. An annular groove associated with each hand guard member is mated with a portion of a flange of the barrel nut. The flange is secured within the annular groove of at least one hand guard member. The delta ring is advanced over a portion of some or all the hand guard members. -
US2012/0324775 discloses a clamp assembly with clamp elements on the barrel nut - In accordance with various embodiments described herein, hand guards that permit a variety of useful accessories to be mounted on firearms are provided, together with methods for mounting the hand guards on the firearms quickly, reliably and without adversely affecting their accuracy.
- The invention provides a hand guard according to claim 1 and a method according to
claim 6. Preferred embodiments are set out in dependent claims. - Some examples are described which assist in understanding the invention.
- In one example, a hand guard for a firearm, such as a rifle, includes an elongated tubular housing comprising an upper part, a lower part, opposite open ends, and an elongated lumen configured to receive an intermediate portion of a barrel of a firearm longitudinally therein. An expansion collar is disposed at one end of the housing. The expansion collar includes an expansion mechanism configured to adjustably compress the expansion collar and the lower part of the housing longitudinally between a pair of surfaces respectively disposed at opposite ends of the intermediate portion of the barrel.
- In another example, a method for using a hand guard with a firearm comprises providing an elongated tubular housing comprising an upper part, a lower part, opposite open ends, and a lumen configured to receive an intermediate portion of a barrel of the firearm longitudinally therein. An expansion collar is also provided. The collar has a longitudinally extending tongue and an expansion mechanism configured to adjustably compress the expansion collar and the lower part of the housing longitudinally between a pair of surfaces respectively disposed at opposite ends of the intermediate portion of the barrel. The tongue of the collar is inserted into an end of the housing to form an assembly, and the assembly is mounted onto a lower surface of the intermediate portion of the barrel and between the surfaces thereon. The expansion mechanism of the collar is then adjusted such that the assembly is held in compression between the surfaces.
- In another example, a hand guard includes an elongated housing. The elongated housing comprises a lumen configured to substantially surround an intermediate portion of a barrel of a firearm, a side wall, and a pair of elongated slots disposed on opposite sides of the side wall. Each of the elongated slots defines a corresponding angulated face of a rail adapted to receive an accessory to be mounted thereon. For example, the rail may be a reduced-height Picatinny rail provided by the side wall of the housing.
- In another example, a method includes inserting at least a portion of an expansion collar into an end of a part of a housing to form an assembly; positioning the assembly over an intermediate portion of a barrel of a firearm and between opposing surfaces thereon; and adjusting an expansion mechanism of the expansion collar such that the assembly is held in compression between the opposing surfaces by advancing a plurality of longitudinally extending screws respectively received in corresponding ones of a plurality of bores contained in the expansion collar such that a distal end of each screw is disposed in abutment with a bottom end surface of a corresponding one of the bores and at least a portion of each screw is loaded in compression.
- In another example, a hand guard for a firearm includes an elongated tubular housing having a lumen extending between opposite ends thereof. A hand guard mounting assembly is coupled concentrically to a rear end portion of the housing. The mounting assembly includes a pair of opposing transverse surfaces respectively disposed on opposite sides of a transverse flange located on a front end of a barrel nut extending forwardly from a receiver of the firearm. At least one of the transverse surfaces is longitudinally moveable toward the other transverse surface. A mechanism adjustably urges the at least one transverse surface longitudinally toward the other transverse surface so as to clamp the flange firmly between the two transverse surfaces and such that the barrel of the firearm is disposed concentrically within the lumen of the housing.
- In another example, a hand guard is provided for a firearm of a type that includes a barrel and a barrel nut extending longitudinally forward from a receiver of the firearm. The hand guard includes an elongated tubular housing having a lumen extending between opposite ends of the housing; a mounting assembly coupled concentrically to a rear end portion of the housing, the mounting assembly including a pair of opposing transverse surfaces respectively disposed on opposite sides of a transverse flange located on a front end of the barrel nut, at least one of the transverse surfaces being longitudinally moveable toward the other transverse surface so as to clamp the flange firmly between the two transverse surfaces and such that the barrel of the firearm is disposed concentrically within the lumen of the housing; and a mechanism for adjustably urging the at least one transverse surface longitudinally toward the other transverse surface.
- In another example, a method is provided for attaching a hand guard to a firearm of a type that includes a barrel, a barrel nut, and a forwardly biased slip ring extending longitudinally forward from a receiver of the firearm. The method includes providing an elongated tubular housing having a lumen extending between opposite ends of the housing and defining at least one accessory mounting rail on an upper surface thereof; and coupling a hand guard mounting assembly to a rear end portion of the housing, the hand guard mounting assembly including: an annular barrel nut interface having a flange extending radially inward at a rear end thereof; the flange defining a forward facing surface comprising at least one tab extending radially inward and conforming in size, shape and location to at least one scallop extending radially inward into a flange located on a front end of the barrel nut; the forward facing surface of the at least one tab having at least one indentation configured to receive a tine extending radially outward from the flange longitudinally therein; and a wedge ring disposed concentrically within the barrel nut interface, the wedge ring defining a rearward facing surface having at least one rearwardly extending land disposed thereon, the at least one land conforming in size, shape and location to the at least one scallop of the flange, and at least one inclined plane disposed on the wedge ring in front of the rearward facing surface and below at least one radially extending set screw disposed in the barrel nut interface.
- The scope of the invention is defined by the claims, which are incorporated into this section by reference. A more complete understanding of embodiments of the invention will be afforded to those skilled in the art, as well as a realization of additional advantages thereof, by a consideration of the following detailed description of one or more embodiments. Reference will be made to the appended sheets of drawings that will first be described briefly.
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Fig. 1A is left side elevation view of an example firearm, namely, an M-16 rifle, of a type to which various hand guards of the present disclosure may be advantageously applied, in which a conventional hand guard has been omitted to reveal a gas tube and an intermediate portion of a barrel thereof, in accordance with an embodiment of the disclosure; -
Fig. 1B is an upper, front, left side perspective view of the receiver and barrel of the rifle ofFig. 1A , showing a first example embodiment of a hand guard in accordance with the present disclosure mounted thereon; -
Fig. 2 is an upper, front, left side perspective view of the first example hand guard ofFig. 1B ; -
Fig. 3 is an upper, front, left side exploded perspective view of the first example hand guard, showing an upper part, a lower part, and an expansion collar thereof; -
Fig. 4A is top plan view of the lower part of the first example hand guard; -
Fig. 4B is a left side elevation view of the lower part; -
Fig. 4C is a rear end elevation view of the lower part; -
Fig. 4D is a right side elevation view of the lower part; -
Fig. 4E is a front end elevation view of the lower part; -
Fig. 4F is a bottom plan view of the lower part; -
Fig. 5A is a top plan view of the upper part of the first example hand guard; -
Fig. 5B is a left side elevation view of the upper part; -
Fig. 5C is a rear end elevation view of the upper part; -
Fig. 5D is a right side elevation view of the upper part; -
Fig. 5E is a front end elevation view of the upper part; -
Fig. 5F is a lower plan view of the upper part; -
Fig. 6 is a cross-sectional view through the first example hand guard, as seen along the lines of the section 6 - 6 taken inFig. 2 ; -
Fig. 7A is a top plan view of the expansion collar part of the first example hand guard; -
Fig. 7B is a front end elevation view of the expansion collar; -
Fig. 7C is a left side elevation view of the expansion collar; -
Fig. 7D is a rear end elevation view of the expansion collar; -
Fig. 7E is a bottom plan view of the expansion collar; -
Fig. 8 is a partial cross-sectional view through the expansion collar, screws, and a front end of the first example hand guard, as seen along the lines of the section 8 - 8 taken inFig. 2 ; -
Fig. 9 is a partial cross-sectional view through the expansion collar, compression members, and a front end of the first example hand guard, as seen along the lines of the section 9 - 9 taken inFig. 2 ; -
Fig. 10 is an upper left side perspective view of a receiver and barrel of an M4 rifle, showing a second example embodiment of a hand guard in accordance with the present disclosure mounted thereon; -
Fig. 11 is an upper, front, right side perspective view of the receiver, barrel and second example hand guard ofFig. 10 , showing an example accessory mounting bracket mounted thereon; -
Fig. 12 is an upper, front, left side perspective view of the second example hand guard ofFigs. 10 and11 ; -
Fig. 13 is an upper, front, left side exploded perspective view of the second example hand guard, showing an upper part, a lower part, and an expansion collar thereof; -
Fig. 14A is top plan view of the lower part of the second example hand guard; -
Fig. 14B is a left side elevation view of the lower part; -
Fig. 14C is a rear end elevation view of the lower part; -
Fig. 14D is a right side elevation view of the lower part; -
Fig. 14E is a front end elevation view of the lower part; -
Fig. 14F is a bottom plan view of the lower part; -
Fig. 15A is a top plan view of the upper part of the second example hand guard; -
Fig. 15B is a left side elevation view of the upper part; -
Fig. 15C is a rear end elevation view of the upper part; -
Fig. 15D is a right side elevation view of the upper part; -
Fig. 15E is a front end elevation view of the upper part; -
Fig. 15F is a lower plan view of the upper part; -
Fig. 16 is a cross-sectional view through the second example hand guard, as seen along the lines of the section 16 - 16 taken inFig. 12 ; -
Fig. 17A is a top plan view of the expansion collar of the second example hand guard; -
Fig. 17B is a front end elevation view of the expansion collar; -
Fig. 17C is a left side elevation view of the expansion collar; -
Fig. 17D is a rear end elevation view of the expansion collar; -
Fig. 17E is a bottom plan view of the expansion collar; -
Fig. 18A is an upper, front, left side perspective view of the example accessory mounting bracket ofFig. 11 ; -
Fig. 18B is an upper, front, right side perspective view of the mounting bracket; -
Figs. 19A - 19C are cross-sectional views of the second example hand guard, as seen along the lines of the section 16 - 16 taken inFig. 12 , showing various accessory and accessory bracket mounting features; -
Fig. 20A is a partial cross-sectional view through the expansion collar, jack screws, and a front end of the second example hand guard, as seen along the lines of thesection 20A - 20A taken inFig. 12 ; -
Fig. 20B is a partial cross-sectional view through the expansion collar, compression members, and the front end of the second example hand guard, as seen along the lines of thesection 20B - 20B taken inFig. 12 ; -
Fig. 21 illustrates a lighting device attached to a clamp mount that may be attached to a lateral side wall of the second example hand guard; -
Fig. 22 illustrates the clamp mount ofFig. 21 ; and -
Fig. 23 illustrates an exploded view of the clamp mount ofFig. 21 . -
Fig. 24 is an upper left side perspective view of portion of an M4 rifle, showing a third example embodiment of a hand guard with a hand guard mounting assembly in accordance with the present disclosure mounted thereon; -
Fig. 25 is an upper, front, left side perspective view of the third example hand guard ofFig. 24 ; -
Fig. 26A is top plan view of the third example hand guard; -
Fig. 26B is a front end elevation view of the third example hand guard; -
Fig. 26C is a left side elevation view of the third example hand guard; -
Fig. 26D is a rear end elevation view of the third example hand guard; -
Fig. 26E is a bottom plan view of the third example hand guard; -
Fig. 27 is a partial cross-sectional view of the third example hand guard and an example embodiment of a hand guard mounting assembly therefor in accordance with the present disclosure, as seen along the lines of the section 27 - 27 taken inFig. 24 ; -
Fig. 28 is an upper left side perspective view of the example hand guard mounting assembly of the third example hand guard ofFig. 27 , wherein the hand guard is omitted for purposes of illustration; -
Fig. 29 is a cross-sectional view of the example hand guard mounting assembly, as seen along the lines of the section 29 - 29 taken inFig. 28 ; -
Fig. 30 is a cross-sectional view of the hand guard mounting assembly, as seen along the lines of the section 30 - 30 taken inFig. 29 ; -
Fig. 31 is a cross-sectional view of the hand guard mounting assembly, as seen along the lines of the section 31 - 31 taken inFig. 29 ; -
Fig. 32 is a cross-sectional view of the of the hand guard mounting assembly, as seen along the lines of the section 32 -32 taken inFig. 28 , wherein a slip ring of the host rifle is omitted for purposes of illustration; -
Fig. 33 is a partial perspective view of the example hand guard and mounting assembly therefore, showing a rear end of the mounting assembly disposed in a flush abutment with a front end of the slip ring of the host rifle; -
Fig. 34 is an upper left side perspective view of the example hand guard mounting assembly, wherein a portion thereof is rendered transparent to reveal internal components therein, including a wedge ring and a barrel ring of the host rifle; -
Fig. 35A is an upper and left side perspective view of a barrel nut interface of the example hand guard mounting assembly; -
Fig. 35B is a front end elevation view of the barrel nut interface; -
Fig. 35C is a left side elevation view thereof; -
Fig. 35D is a rear end elevation view thereof; -
Fig. 36A is an upper and left side perspective view of a wedge ring of the example mounting assembly; -
Fig. 36B is a front end elevation view of the example wedge ring; -
Fig. 36C is a left side elevation view thereof; -
Fig. 36D is a rear end elevation view thereof; -
Fig. 37A is an upper and left side perspective view of a barrel nut of a type utilized in a host rifle, with which the example hand guard and hand guard mounting assembly of the present invention interface; -
Fig. 37B is a front end elevation view of the barrel nut; -
Fig. 37C is a left side elevation view thereof; -
Fig. 37D is a rear end elevation view thereof; -
Fig. 38A is an upper and left side perspective view of a slip ring of a type utilized in a host rifle; -
Fig. 38B is a front end elevation view of the slip ring; -
Fig. 38C is a left side elevation view thereof; -
Fig. 38D is a rear end elevation view thereof; -
Fig. 39A is a upper and left front perspective view of a slip-ring spring of a type utilized in conjunction with the slip ring ofFigs. 38A - 38D ; -
Fig. 39B is a left side elevation view of the slip-ring spring; -
Fig. 39C is a rear end view of the slip-ring spring; -
Fig. 40 is a front end elevation view of a snap ring of a type utilized in conjunction with the slip ring ofFigs. 38A - 38D ; -
Fig. 41 is a partial top plan view of an example accessory mounting rail shown mounted to the example hand guard ofFig. 24 in accordance with the present disclosure, as seen along the lines of the section 41 - 41 taken therein; -
Fig. 42A is a top plan view of the accessory mounting rail; -
Fig. 42B is a left side elevation view thereof; -
Fig. 42C is a bottom plan view thereof; -
Fig. 42D is a right side elevation view thereof; -
Fig. 43A is a cross-sectional view of the accessory mounting rail and an example fastener used to fasten it to the example hand guard, as seen along the lines of the section 43 -43 taken inFig. 42C ; -
Fig. 43B is a cross-sectional view of the accessory mounting rail and the example fastener, as seen along the lines of the section 43 -43 taken inFig. 42C while the accessory mounting rail is attached to the hand guard; -
Fig. 44A is a top plan view of the fastener ofFig. 43A ; -
Fig. 44B is a left side elevation view of the fastener; -
Fig. 44C is a bottom plan view thereof; and -
Fig. 45 is an upper, front, left side perspective view of another example hand guard of a type similar to that ofFig. 24 , in accordance with the present disclosure. - Embodiments of the invention and their advantages are best understood by referring to the detailed description that follows. It should be appreciated that like reference numerals are used to identify like elements illustrated in one or more of the figures.
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Figure 1A is left side elevation view of an example firearm, namely, an M-16rifle 10, of a type with which embodiments of the novel hand guard of the present disclosure can be advantageously utilized. The M16, and a variant thereof, viz., the M4, has generally replaced the M14 and M1 carbine as the standard infantry rifles of the U.S. armed forces. Currently, the M16 is the most commonly manufactured 5.56x45 mm rifle in the world, and is in use by 15 NATO countries and more than 80 countries worldwide. Numerous companies in the United States, Canada, and China have, together, produced more than 8,000,000 M-16 rifles, in all of its many variants, of which approximately 90% are still in operation. - As can be seen in
Fig. 1A , theexample rifle 10 includes areceiver 12 having a combined carrying handle andrear sight 14, a rear orshoulder stock 16 extending rearwardly from thereceiver 12, a pistol-type hand grip 18, atrigger 20 for firing therifle 10, amagazine 22 for holding ammunition, anelongated barrel 24 extending forwardly from thereceiver 12, anupstanding front sight 26 mounted forwardly on thebarrel 24, and alongitudinal axis 28 concentric with thebarrel 24. Extending rearwardly from thefront sight 26 to thereceiver 12 is agas tube 30 that conveys combustion gases from a port (not seen inFig. 1A ) in thebarrel 24 located below thefront sight 26 to thereceiver 12, which are used by components in the receiver for the automatic actuation of therifle 10 when it is fired. - The
example rifle 10 also conventionally includes a hand guard, typically made of a plastic composite, that surrounds thegas tube 30 and anintermediate portion 32 of thebarrel 24. However, inFig. 1A , the conventional hand guard has been omitted for purposes of explication. As illustrated inFig. 1A , theintermediate portion 32 of thebarrel 24 includes a pair of front and rear radial surfaces 34 and 36 respectively disposed at opposite ends thereof. The frontradial surface 34 comprises the rear surface of a hand guardforward support cap 38, and the rearradial surface 36 comprises the front surface of a threaded hand guard rear slip ring retainer 40 (also referred to as a barrel nut). As discussed in more detail below, the tworadial surfaces intermediate portion 32 of thebarrel 24 can, in some embodiments, provide features that are advantageous for mounting ahand guard 100 in accordance with the present disclosure on therifle 10. -
Fig. 1B is an upper, front, left side perspective view of thereceiver 12 andbarrel 24 of therifle 10 ofFig. 1A , showing a first example embodiment of ahand guard 100 in accordance with the present disclosure mounted thereon.Figs. 2 and3 are upper, front, left side perspective and exploded perspective views of theexample hand guard 100, respectively. As illustrated inFigs. 2 and3 , theexample hand guard 100 comprises an elongatedtubular housing 102 having anupper part 104, alower part 106, opposite open ends 108 and 110, and alumen 112 configured to receive thegas tube 30 andintermediate portion 32 of thebarrel 24 of thefirearm 10 longitudinally therein. - As illustrated in the cross-sectional view of the
housing 102 inFig. 6 , thehousing 102 can have a generally polygonal cross-section, and in the particular embodiment illustrated, thehousing 102 has eight side walls, i.e., is octagonal in cross-sectional shape. Other cross-sectional shapes, including round or annular, can also be used. At least one of the side walls of thehousing 102 can comprise a longitudinalaccessory mounting rail 113, such as specified in MIL-STD-1913 and commonly referred to as a "Picatinny" rail, or other type of rail. In the particular example embodiment illustrated inFig. 6 , four suchaccessory mounting rails 113 are provided, disposed in alternating fashion around the circumfery of thehousing 102, one comprising the top side wall of theupper part 104 of thehousing 102, and three comprising the two lateral and one bottom side walls of thelower part 106 thereof. - As shown in
Fig. 1B , whenhand guard 100 is installed onreceiver 12, atop rail 113 onupper part 104 may be substantially level with another rail 170 (e.g., another longitudinal accessory mounting rail such as another Picatinny rail or other type of rail). Such positioning ofrails rails rails 113 and 170 (e.g., using mounting locations of bothrails 113 and 170). - One or more accessories many be mounted on
rails 113 such as, for example, lighting devices, sighting devices, and/or others. For example, as identified inFig. 3 , a lighting device 190 (e.g., a SureFire Scout Light in one embodiment) may be provided to be mounted on rails 113 (e.g., directly and/or with arail clamp 192, such as a SureFire M93 Swing-Lever WeaponLight Rail Clamp in one embodiment and/or as identified inU.S. Patent No. 8,127,484 ). - In some embodiments,
upper part 104 may include one or more protrusions 182 (e.g., one or more flanges or individual protruding members) configured to engage or contact receiver 12 (seeFigs. 1B and3 ). For example,protrusion 182 may extend over, rest upon, and/or push against various external portions ofretainer 40 and/or ofrear sight 14. In some embodiments,lower part 106 may include one or more protrusions 180 (e.g., implemented as one or more flanges or individual protruding members) configured to engage or contact receiver 12 (seeFigs. 1B and3 ). For example, protrusions 180 may rest upon and/or push againstretainer 40. In various embodiments, protrusions 180 and/orflanged portion 182 may be used to furthersecure hand guard 100 to rifle 10. - As illustrated in
Figs. 2 ,3 ,8, and 9 , theexample hand guard 100 further comprises anexpansion collar 114 disposed at one end of thehousing 102. Theexpansion collar 114 incorporates an expansion mechanism, described below, configured to adjustably compress theexpansion collar 114 and thelower part 106 of thehousing 102 longitudinally between theradial surfaces intermediate portion 32 of thebarrel 24, as described above. In the particular embodiment illustrated in the figures, theexpansion collar 114 is shown disposed adjacent to thefront end 108 of thehousing 102, but as those of some skill in the art will appreciate, this arrangement can be reversed, such that theexpansion collar 114 is disposed adjacent to therear end 110 of thehousing 102. - Additionally, as illustrated in, e.g.,
Figs. 2 ,3 ,7A, 7C, and 7D , theexpansion collar 114 can include alongitudinal tongue 116 that can be slid into a complementary recess in the adjacent open ends 108 or 110 of thehousing 102 to generally align thecollar 114 concentrically with thehousing 102 and thelumen 112 thereof. - As illustrated in, e.g.,
Figs. 2 ,3 and8 , in one embodiment, the expansion mechanism can comprise a plurality, e.g., two or more, of longitudinally extending screws 118 (e.g., also referred to as jack screws) respectively received in corresponding ones of a plurality of threadedapertures 120 contained in theexpansion collar 114. Eachscrew 118 has adistal end 122 that can be urged into abutment with an adjacent end, 108 or 110 of thelower part 106 of thehousing 102. In some embodiments, theend housing 102, against which the distal ends 122 of thescrews 118 bear, can be protected against any resultant deformation and wear caused by abutment of the screw ends 122 by the provision of a corresponding plurality ofwear pads 124 made of, e.g., a hard metal, disposed in corresponding,complementary recesses 126 in the adjacent end of thelower part 106 of thehousing 102. The distal ends 112 of thescrews 118 can then respectively bear on thepads 124 with virtually no resulting wear or deformation of the adjacent end of thelower part 106 of the housing. In addition, asscrews 118 are tightened, the longitudinal expansion ofhand guard 100 may cause protrusions 180 to push againstretainer 40 and thus tightenend 110 ofhand guard 100 againstrifle 10. - As illustrated in, e.g.,
Figs. 3 and9 , in some embodiments, the expansion mechanism can further include a plurality ofelongated compression members 128 that extend longitudinally from an end of theexpansion collar 114 opposite to the end of thehousing 102 at which theexpansion collar 114 is disposed. As illustrated inFig. 9 , thecompression members 128 can include afirst end portion 130 that can comprise a material that may compress and expand (e.g., being at least partially deformable, compressible, and/or expandable) while still remaining relatively resilient, such as rubber or polyurethane, which is disposed in a corresponding bore 132 (seeFig. 7B ) in theexpansion collar 114, and an oppositesecond end 134 comprising a relatively harder bearing material, e.g., a metal, such as steel. - In some embodiments, the
example hand guard 100 can be mounted on an associatedrifle 10 in accordance with the following example mounting method, in which it is assumed that theexpansion collar 114 is mounted at thefront end 108 of thehousing 102 and disposed adjacent to the frontradial surface 34, as illustrated in the example embodiment ofFigs. 1A and 1B . - First, the upper part of the
housing 102 is removed from thelower part 106, which can be effected in a manner described in more detail below. Thelongitudinal tongue 116 of theexpansion collar 114 is inserted into thefront end 108 of thelower part 106 of thehousing 102 to form a loose assembly therewith. The assembly of theexpansion collar 114 andlower part 106 of thehousing 102 is then mounted onto the lower surface of theintermediate portion 32 of therifle barrel 24 and between theradial surfaces compression members 128 of theexpansion collar 114 disposed adjacent to the frontradial surface 34 and therear end 110 of thelower part 106 of thehousing 102 disposed adjacent to the rearradial surface 36. In one embodiment, the assembly of theexpansion collar 114 andlower part 106 of the housing may be positioned around (e.g., without touching) theintermediate portion 32 of therifle barrel 24 and rotated thereabout until thelower part 106 of thehousing 102 is disposed beneath therifle barrel 24. - As illustrated in
Fig. 8 , thescrews 118 are then advanced in their respective threadedapertures 120 in theexpansion collar 114 such that thedistal end 122 of eachscrew 118 engages acorresponding pad 124 in the adjacent end of thelower part 106 of thehousing 102. As indicated by thearrows 136 inFigs. 8 and 9 , further advancement of thescrews 118 causes thelower part 102 andexpansion collar 114 to spread apart from each other, thereby loading the entire longitudinal assembly comprising thecompression members 128, theexpansion collar 114, and thelower part 106 of thehousing 102, in compression between the tworadial surfaces rifle 10. - As those of some skill will appreciate, this compressive force results in a reactive longitudinal tensile force being applied to the
barrel 24 of therifle 10, which, unlike various prior hand guards, does not result in any twisting or local deformations of thebarrel 24, and therefore does not adversely affect the accuracy of therifle 10. Any differences in the respective forces exerted by thescrews 118 are taken up by the plurality ofcompression members 128, which compress or expand locally (e.g., performed by the material of first end portion 130) to ensure that the force exerted by thescrews 118 is substantially uniformly distributed among the compression members and on the adjacent end of thelower part 106 of thehousing 102. although such compression and expansion is described as being performed by the material offirst end portion 130 ofcompression members 128, such material may be provided by any component ofhand guard 100. For example, in one embodiment, such material may be provided as part ofscrews 118 and/or other components adapted to compress and expand betweenend 108 andsurface 34. - One of the many advantages provided by embodiments of the first
example hand guard 100 of the present disclosure is that theupper part 104 of thehousing 102 can be removed from thelower part 106 of thehousing 102, e.g., to gain access to thegas tube 30 and/or theintermediate portion 32 of thebarrel 24, without having to remove thelower part 106 andexpansion collar 114 from therifle 10. As illustrated in, e.g.,Figs. 3 and6 , this can be effected by the provision of a coupling mechanism for releasably coupling theupper part 104 of thehousing 102 to thelower part 106 thereof. Moreover, thelower part 106 may remain tightly engaged withsurfaces 34 and 36 (e.g., by longitudinal expansion) while theupper part 104 is removed. As a result, accessories installed ontolower part 106 may remain attached and in alignment while theupper part 104 is removed. Also, accessories installed ontoupper part 104 may also remain attached and in alignment while theupper part 104 is removed. Therefore, ifupper part 104 is subsequently attached tolower part 106, all accessories attached tohand guard 100 may be aligned and ready for use without requiring further adjustment by the user. - In other embodiments, the locations and/or configurations of
upper part 104 and/orlower part 106 may be changed. For example, in one embodiment, the locations ofupper part 104 andlower part 106 may be reversed such thatupper part 104 is actually positioned belowlower part 106 whilehand guard 100 is installed onintermediate portion 32 ofbarrel 24. In such an embodiment,upper part 104 may be lowered downward from rifle 10 (e.g., lowered down on the trigger side of rifle 10) whilelower part 106 remains installed (e.g., positioned on a top side ofrifle 10 and straddlingintermediate portion 32 of barrel 24). - As illustrated in, e.g.,
Figs. 3 ,5C , and5E , theupper part 104 of thehousing 102 can include a pair of laterally spaced, downwardly extendingside walls 138, each having alower edge 140 and a generally planarexterior surface 142. As illustrated in, e.g.,Figs. 3 and6 , thelower part 106 of thehousing 102 can have a pair of laterally spaced, upwardly extendingside walls 141, each of which has a generally planarinterior surface 144, with aledge 146 disposed at a lower edge thereof. As illustrated inFig. 6 , theside walls 138 of theupper part 104 are positionable inside theside walls 141 of thelower part 106 such that respective ones of the planar exterior surfaces 142 of theside walls 138 of theupper part 104 are disposed in facing opposition to corresponding ones of the planarinterior surfaces 144 of theside walls 141 of thelower part 102. As illustrated in, e.g.,Figs. 3 ,4B ,4D and6 , the coupling mechanism can comprise a plurality of threadedfasteners 148 respectively extending laterally through apertures 150 (e.g., openings) in corresponding ones of theside walls 141 of thelower part 106 of thehousing 102 and into corresponding threadedapertures 152 disposed in corresponding ones of theside walls 138 of theupper part 104 of thehousing 102, and arranged such that advancement of thefasteners 148 into the threadedapertures 152 acts to pull theplanar surfaces 142 of theside walls 138 of theupper part 104 into engagement with corresponding ones of theplanar surfaces 144 of theside walls 141 of thelower part 106. In one embodiment, threadedapertures 152 may be provided byside walls 138 of the upper part 104 (e.g., integral therewith). In another embodiment, threadedapertures 152 may be provided by separate components (e.g., nuts or bushings) that are pressed, welded, and/or otherwise attached positioned intoapertures 151 of the upper part 104 (e.g., positioned withinlumen 112 whenhand guard 100 is assembled). - Additionally, in some embodiments, the threaded
apertures 152 in theside walls 138 of theupper part 104 can be respectively disposed a first distance above thelower edge 140 of thecorresponding side wall 138 of theupper part 104, and theapertures 150 in theside walls 141 of thelower part 106 can be respectively disposed a second distance above theledge 146 of thecorresponding side wall 141. The first distance can be made slightly greater than the second distance (e.g., greater by a distance of approximately 8 thousandths of an inch in one embodiment), such that advancement of the threadedfasteners 148 into the threadedapertures 152 further acts to pull thelower edges 140 of theside walls 138 of theupper part 104 into a tight engagement with the correspondingledges 146 of theside walls 141 of thelower part 106, thus ensuring a tight coupling of theupper part 104 to thelower part 106. - In some embodiments, as shown in
Fig. 3 ,apertures 150 may be implemented withcountersinks 155. In one embodiment, countersinks 155 may be offset downward or otherwise (e.g., by approximately 8 thousandths of an inch in one embodiment) such that upper portions ofheads 149 of threadedfasteners 148contact rail 113 and/or thelower part 106 before threadedfasteners 148 are fully screwed into threadedapertures 152 and fully seated withincountersinks 155. Such contact can provide compressive force to further secureupper part 104 andlower part 106 together. - As illustrated in, e.g.,
Figs. 2 and3 , selected ones or all of the side walls of thehousing 102 can include a pattern of vent holes 154 extending therethrough. The vent holes 154 serve to reduce the weight of the hand guard substantially, and can also serve both to cool thebarrel 24 of therifle 10 during extended firing thereof, thereby ensuring that thehand guard 100 remains cool to the touch, and also to mount certain types of accessories to the hand guard 100 (e.g., such aslighting device 190 in one embodiment). In various embodiments, accessories may be mounted directly to vent holes 154 (e.g., without requiringrail clamp 192 or other mounting mechanisms). -
Fig. 10 is an upper left side perspective view of a receiver and barrel of an M4 rifle 10 (e.g., withrear sight 14 removed), showing a second example embodiment of ahand guard 200 in accordance with the present disclosure mounted thereon, andFig. 11 is an upper, front, right side perspective view of the receiver, barrel and secondexample hand guard 200 ofFig. 10 , showing an exampleaccessory mounting bracket 201 mounted on the right side thereof. - As can be seen from a comparison of the figures respectively illustrating the first and second
example hand guards example hand guards radial surfaces rifle 10, coupling mechanisms and engagement surfaces, features in the side walls of the hand guard housing that enable various accessory mounting brackets to be coupled to it efficiently and reliably, and other features further discussed herein. -
Figs. 12 and13 are upper, front, left side perspective and exploded perspective views of the secondexample hand guard 200, respectively. As illustrated inFigs. 12 and13 , the secondexample hand guard 200 can, like thefirst example embodiment 100 above, comprise an elongatedtubular housing 202 having anupper part 204, alower part 206, opposite open ends 208 and 210, and alongitudinal lumen 212 configured to accommodate thegas tube 30 andintermediate portion 32 of thebarrel 24 of therifle 10 longitudinally therein. - As illustrated in the cross-sectional view of the
housing 202 inFigs. 16 and19A - 19C , thehousing 202 can have a generally polygonal cross-section, and in the particular embodiment illustrated, thehousing 202 has eight side walls, i.e., has a cross-sectional shape that is octagonal. Of course, other cross-sectional shapes, including round or annular, can also be used. At least one of the side walls of thehousing 202 can comprise an integrally formed, longitudinalaccessory mounting rail 213, such as specified in MIL-STD-1913 and commonly referred to as a "Picatinny" rail, or as discussed below, a variation thereof. In the particular example embodiment illustrated inFigs. 16 and19A - 19C , two such integralaccessory mounting rails 213 are provided, i.e., one disposed atop the top wall of theupper part 204 of thehousing 202, and one disposed on the bottom wall of thelower part 206 thereof. - As illustrated in
Figs. 10 and11 , when the secondexample hand guard 200 is installed on thereceiver 12 of therifle 10, atop rail 213 on theupper part 204 can be disposed substantially level with another rail 270 (e.g., another longitudinal accessory mounting rail, such as another Picatinny rail or other type of rail). Such positioning of therails rails rails 213 and 270 (e.g., using the mounting locations of bothrails 213 and 270). As discussed above in connection with thefirst example embodiment 100, one or more accessories can be mounted on therails 213 such as, for example, lighting devices, sighting devices, and/or other types of devices. - In some embodiments, the
upper part 204 can include one or more protrusions 282 (e.g., one or more flanges or individual protruding members) configured to engage or overlie a front end portion of the receiver 12 (see, e.g.,Figs. 10 - 12 ). For example, theprotrusion 282 can extend over, rest upon, and/or push against various external portions of theretainer 40. In some embodiments, thelower part 206 can include one or more protrusions 280 (e.g., implemented as one or more flanges or individual protruding fingers) configured to engage or contact the retainer (e.g., barrel nut) 40 (see, e.g.,Figs. 12 and13 ). For example, theprotrusions 280 can rest upon and/or push against theretainer 40. In various embodiments, theprotrusions 280 and/or theflanged portion 282 can be used to further secure thehand guard 200 to therifle 10. - As illustrated in, e.g.,
Figs. 12 ,13 ,17A - 17E ,20A and 20B , the secondexample hand guard 200 also comprises anexpansion collar 214 disposed at one end of the housing 202.Theexpansion collar 214 incorporates an expansion mechanism, described in more detail below, that is configured to adjustably compress theexpansion collar 214 and thelower part 206 of thehousing 202 longitudinally between theradial surfaces intermediate portion 32 of thebarrel 24, as described above. In the particular embodiment illustrated in the figures, theexpansion collar 214 is shown disposed adjacent to thefront end 208 of thehousing 202, but as those of some skill in this art will appreciate, this arrangement can be reversed, such that theexpansion collar 214 is disposed adjacent to therear end 210 of thehousing 202. - Additionally, as illustrated in, e.g.,
Figs. 13 and17A - 17E , theexpansion collar 214 can include a pair oflongitudinal tongues 216 that can be slid into a complementary recess in the adjacent open ends 208 or 210 of thehousing 202 to generally align thecollar 214 concentrically with thehousing 202 and thelumen 212 thereof. - As illustrated in, e.g.,
Figs. 13 and20A , in one embodiment, the expansion mechanism can comprise a pair of longitudinally extending screws 218 (also referred to herein as jack screws) respectively received in corresponding ones of a pair of threadedapertures 217 respectively contained in a corresponding pair of laterally opposingstanchions 219 respectively attached to the inner surfaces of theside walls 241 of thelower part 206. In the particular example embodiment illustrated in the figures, each of the two side wall stanchions 219 is attached to acorresponding side wall 241 of thelower part 206 by a pair of threadedfasteners 221 that extend through corresponding through-apertures in theadjacent side wall 241 and into corresponding threaded apertures in thestanchions 219. However, as those of some skill will understand, thestanchions 219 can be coupled or connected to theside walls 241 of thelower part 206 using other methods, such as brazing, welding, staking, riveting, adhesive bonding and so on. - As illustrated in
Figs. 17D and20A , each of thelongitudinal tongues 216 of theexpansion collar 214 includes alongitudinal bore 220 having an open side and abottom end surface 224. Eachjack screw 218 has a distal end that can be urged into abutment with an corresponding one of the bottom end surfaces 224 of thelongitudinal bores 220 by advancing thejack screw 218 in the threadedaperture 217 of thecorresponding stanchion 219. Thus, as thescrews 218 are advanced within the threadedapertures 217 of the stanchions 219 (e.g., in an opposite direction asscrews 118 of hand guard 100), the resulting longitudinal expansion of thehand guard 200 causes theprotrusions 280 to push against theretainer 40 and thereby tighten theend 210 of thehand guard 200 against the forward facingsurface 36 of thereceiver 12 of therifle 10. - As illustrated in, e.g.,
Figs. 13 and20B , in some embodiments, the expansion mechanism can further include a plurality ofelongated compression members 228 that extend longitudinally from an end of theexpansion collar 214 opposite to the end of thehousing 202 at which theexpansion collar 214 is disposed. As illustrated inFig. 20B , thecompression members 228 can include afirst end portion 230 that can comprise a material that can compress and expand (e.g., being at least partially deformable, compressible, and/or expandable) while still remaining relatively resilient, such as a rubber or polyurethane, which is disposed in a corresponding bore 232 (see, e.g.,Fig. 17B ) in theexpansion collar 214, and an oppositesecond end 234 that can comprise a relatively harder bearing material, e.g., a metal, such as steel or aluminum. - In some embodiments, the second
example hand guard 200 can be mounted on an associatedrifle 10 in accordance with the following example mounting method, in which it is assumed that theexpansion collar 214 is mounted at thefront end 208 of thehousing 202 and disposed adjacent to the frontradial surface 34 of therifle 10, as illustrated in the example embodiment ofFigs. 10 and11 . However, as discussed above, this orientation can be reversed, if desired. - First, the
upper part 204 of thehousing 202 is removed from thelower part 206, which can be effected in a manner described in more detail below. Thelongitudinal tongues 216 of theexpansion collar 214 are inserted into thefront end 208 of thelower part 206 of thehousing 202 to form a loose assembly therewith. The assembly of theexpansion collar 214 andlower part 206 of thehousing 202 is then mounted onto the lower surface of theintermediate portion 32 of therifle barrel 24 and between theradial surfaces compression members 228 of theexpansion collar 214 disposed adjacent to the rear-facingfront surface 34 and therear end 210 of thelower part 206 of thehousing 202 disposed adjacent to the front-facingrear surface 36. In one embodiment, the assembly of theexpansion collar 214 andlower part 206 of thehousing 202 can be positioned around (e.g., without touching) theintermediate portion 32 of therifle barrel 24 and rotated thereabout until thelower part 206 of thehousing 202 is disposed below therifle barrel 24. - As illustrated in
Figs. 20A and 20B , thescrews 218 are then advanced in their respective threadedapertures 217 in thestanchions 219 such that the distal end of eachscrew 218 is disposed in abutment with corresponding one of the bottom end surfaces 224 of thelongitudinal bores 220 in thetongues 216 of theexpansion collar 214. As indicated by thearrows 236 inFigs. 20A and 20B , further advancement of thescrews 218 causes thelower part 206 and theexpansion collar 214 to spread apart from each other longitudinally, thereby loading the entire longitudinal assembly comprising thecompression members 228, theexpansion collar 214, and thelower part 206 of thehousing 202, in compression between the tworadial surfaces rifle 10. - As those of some skill will appreciate, this compressive force results in a reactive longitudinal tensile force being applied to the
barrel 24 of therifle 10, which, unlike various prior hand guards, does not result in any twisting or local deformations of therifle barrel 24, and therefore, does not adversely affect the accuracy of therifle 10. Any differences in the respective forces exerted by thescrews 218 are taken up by the plurality ofcompression members 228, which compress or expand locally (e.g., effected by the resilient material of first end portion 230) to ensure that the force exerted by thescrews 218 is substantially uniformly distributed among thecompression members 228 and on the adjacent end of thebottom part 206 of thehousing 202. Although such compression and expansion is described as being effected by the material of thefirst end portions 230 ofcompression members 228, such operation can also be provided by any component of thehand guard 200. For example, in one embodiment, this function may be effected by, for example, a spring comprising a part of thejack screws 218 and/or other components adapted to compress and expand between theend 208 of thelower part 206 of thehousing 202 and the rear-facingradial surface 34. - One of the many advantages provided by the embodiments of the
hand guard upper part housing lower part housing gas tube 30 and/or theintermediate portion 32 of thebarrel 24, without having to remove thelower part expansion collar rifle 10. As illustrated in, e.g.,Figs. 13 and16 , this can be effected in the case of the secondexample hand guard 200 by the provision of a coupling mechanism for releasably coupling theupper part 204 of thehousing 202 to thelower part 206 thereof. Moreover, thelower part 206 can remain tightly engaged withsurfaces 34 and 36 (e.g., by longitudinal expansion) while theupper part 204 is removed. As a result, accessories installed on thelower part 206 can remain attached and in alignment with therifle 10 while theupper part 204 is removed. Also, any accessories installed onto theupper part 204 can also remain attached and in alignment with theupper part 204 when theupper part 204 is removed. Thus, if theupper part 204 is subsequently re-attached to thelower part 206, all accessories attached to thehand guard 200, whether mounted on theupper part 204 or thelower part 206 will remain aligned and ready for use without requiring further adjustment by the user. - In other embodiments, the locations and/or configurations of the
upper part 204 and/orlower part 206 can be changed. For example, in one embodiment, the locations of theupper part 204 andlower part 206 can be reversed such thatupper part 204 is actually positioned below thelower part 206 whilehand guard 200 is installed onintermediate portion 32 ofbarrel 24. In such an embodiment, theupper part 204 can be lowered downward from rifle 10 (e.g., lowered down to the trigger side of rifle 10) whilelower part 206 remains installed (e.g., positioned on a top side of therifle 10 and straddling theintermediate portion 32 of the barrel 24). Indeed, in this embodiment (and applicable tohand guard 100 and 200), it is possible to omit theupper part 104/204 entirely and install, for example, a grenade launcher or other component in its place below thebarrel 24 of therifle 10. In other embodiments,upper part 104/204 may be omitted whilelower part 106/206 is positioned on a bottom side of the rifle 10 (e.g., to permit installation of any desired apparatus in place ofupper part 104/204 above barrel 24). In any case, omission ofupper part 104/204 may also permit the user to gain access tobarrel 24, gas tube 30 (e.g., in some embodiments,gas tube 30 may not be accessible whileupper part 104/204 is removed), and/or other portions ofrifle 10 whilelower part 106/206 remains installed in a position on a bottom side or top side ofrifle 10. - As illustrated in, e.g.,
Figs. 13 ,15B ,15C , and15E , theupper part 204 of thehousing 202 can include a pair of laterally spaced, downwardly extendinglateral side walls 238, and inclined side walls 239 (e.g., inclined approximately 45 degrees relative to side walls 238). Each ofside walls 238 include a generally planarexterior surface 242 and a flange 243 (e.g., a downwardly projecting engagement surface extending over lateral side walls 238). As illustrated in, e.g.,Figs. 13 ,14C , and16 , thelower part 206 of thehousing 202 can have a pair of laterally spaced, upwardly extendinglateral side walls 241, and inclined side walls 247 (e.g., inclined approximately 45 degrees relative to side walls 241). Each ofside walls 241 has a generally planarinterior surface 244 and also an upper edge 245 (e.g., an upwardly projecting engagement surface at the intersection of angulated faces 255A-B). As illustrated inFigs.16 and19A - 19C , theside walls 238 of theupper part 204 are positionable inside theside walls 241 of thelower part 206 such that respective ones of the planar exterior surfaces 242 of theside walls 238 of theupper part 204 are disposed in facing opposition to corresponding ones of the planarinterior surfaces 244 of theside walls 241 of thelower part 206. Moreover,flange 243 ofupper part 204 may be brought into contact withupper edge 245 oflower part 206. - As illustrated in, e.g.,
Figs. 12 and13 , the coupling mechanism can comprise a plurality of threadedfasteners 248 respectively extending laterally throughapertures 250 in corresponding ones of theside walls 241 of thelower part 206 of thehousing 202 and into corresponding threadedapertures 252 disposed in corresponding ones of theside walls 238 of theupper part 204 of thehousing 202, and arranged such that advancement of thefasteners 248 into the threadedapertures 252 acts to pull theplanar surfaces 242 of theside walls 238 of theupper part 204 into engagement with corresponding ones of theplanar surfaces 244 of theside walls 241 of thelower part 206. In one embodiment, the threadedapertures 152 can be provided in theside walls 238 of the upper part 204 (e.g., integral therewith). In another embodiment, the threadedapertures 252 can be provided by separate components (e.g., nuts or bushings) that are pressed, welded, and/or otherwise attached positioned into corresponding apertures in the upper part 204 (e.g., positioned within thelumen 212 when thehand guard 200 is assembled). - Additionally, in some embodiments, the threaded
apertures 252 in theside walls 238 of theupper part 204 can be disposed such that they are slightly higher (e.g., offset by a distance of 8 thousandths of an inch in one embodiment) than theapertures 250 in theside walls 241 of thelower part 206 whenupper part 204 is inserted into lower part 206 (e.g., whenflanges 243 ofupper part 204 are in contact withupper edges 245 oflower part 206 but beforeupper part 204 andlower part 206 have been secured together). As threadedfasteners 248 are advanced into the threadedapertures 252, the offset betweenapertures causes flanges 243 of theside walls 238 of theupper part 204 to be pulled into a tight engagement with theupper edges 245 of theside walls 241 of thelower part 206, thus ensuring a tight coupling of theupper part 204 to thelower part 206. - As illustrated in
Fig. 13 , in some embodiments, theapertures 250 can be implemented with frustoconical countersinks. In one embodiment, the countersinks can be offset downward or otherwise (e.g., by approximately 8 thousandths of an inch in one embodiment) such that the upper portions of the heads of the threadedfasteners 248 contact therail 213 and/or thelower part 206 before the threadedfasteners 248 are fully screwed into the threadedapertures 252 and fully seated within the corresponding countersinks. Such contact can provide compressive force to further secure theupper part 204 and thelower part 206 together. - As illustrated in, e.g.,
Figs. 12 and13 , selected ones or all of the side walls of thehousing 102 can include a pattern of apertures 251 (e.g., in upper part 204) and 259 (e.g., in lower part 206).Apertures example hand guard 200 substantially, and also permit cooling of thebarrel 24 of therifle 10 during extended firing thereof, thereby ensuring that thehand guard 200 remains cool to the touch. - Additionally, as discussed below,
apertures elongated slots 254A-B to definerails 289 which may be used to mount accessories to thehand guard 200, e.g., such as, for example, rails 262 illustrated inFigs. 10 ,19A, and 19B , theaccessory mounting bracket 201 illustrated inFig. 11 , and/or other accessories. In some embodiments,slots 254A may be defined byapertures 251 ininclined side walls 239 ofupper part 204 andupper edge 245 oflower part 206. In some embodiments,slots 254B may be defined entirely byapertures 259 ininclined side walls 247 oflower part 206. -
Figs. 19A - 19C are cross-sectional views of the secondexample hand guard 200, as seen along the lines of the section 16 - 16 taken inFig. 12 , showing various accessory and accessory bracket mounting features. As discussed above and illustrated inFigs. 19A - 19C , at least one of the side walls of thehousing 202 can comprise an integral, longitudinalaccessory mounting rail 213, such as specified in MIL-STD-1913 and commonly referred to as a "Picatinny" rail. In the particular example embodiment illustrated in the figures, thehousing 202 includes two such integralaccessory mounting rails 213, viz., one disposed atop the top wall of theupper part 204 of thehousing 202, and one disposed on the bottom wall of thelower part 206 of thehousing 202. In this regard, each side ofrails 213 include two angulated faces 253A-B (seeFigs. 19A-C ) which subtend an angle θ of about 90 degrees, and the width w between the respective intersection of the angulated faces 253A-B on either side of eachrail 213 is about 0.835 inches. - Additional side rails 289 may be provided with "Picatinny rail" features, but having a substantially reduced height relative to conventional Picatinny rails 213 (e.g., without the "neck"
portion 256 of the conventional Picatinny rail 213). In this regard, rails 289 include angulated faces 255A-B and 255C-D provided on opposite sides oflateral side walls 241 and proximate toslots 254A-B. Slots 254A (e.g., having perimeters defined byapertures 251 ininclined side walls 239 ofupper part 204 andupper edge 245 oflower part 206 as discussed) define angulated faces 255A (e.g., interior facing angulated faces corresponding to portions ofupper edge 245 of lower part 206).Slots 254B (e.g., having perimeters defined byapertures 259 ininclined side walls 247 oflower part 206 as discussed) define angulated faces 255C (e.g., interior facing angulated faces). External surfaces oflateral side walls 241 may provide angulated faces 255B and 255D (e.g., exterior facing angulated faces). - Angulated faces 255A-B and 255C-D of
rails 289 may exhibit the same angle θ and the same width w as described for angulated faces 253A-B ofrails 213. However, as can be seen inFigs. 19A-C , the respectiveouter surfaces 291 ofrails 289 are generally coplanar with the respective outer surfaces of theside walls 241 of thelower part 206. Thus, the "neck"portion 256 of theconventional Picatinny rail 213 is eliminated inrails 289, resulting in a lighter, narrower, easier-to-grip hand guard 200 without any sacrifice in accessory mounting capabilities. -
Fig. 18A is an upper, front, left side perspective view of the exampleaccessory mounting bracket 201 shown inFig. 11 , andFig. 18B is an upper, front, right side perspective view thereof. Thebracket 201 can be configured to mount, for example, a light 190 discussed above in connection withFig. 3 . As illustrated inFig. 18A , in some embodiments, the mountingbracket 201 can comprise two pairs offingers fingers 258A can be fixed on thebracket 201 and the other pair offingers 258B can be arranged to pivot toward and away from the fixedpair 258A, for example, by depressing the head of an actuatingmember 260 of the type illustrated inFig. 18B . As illustrated inFig. 19C , this arrangement enables the mountingbracket 201 to be clamped to a side wall (e.g., asfingers 258A-B extend through slots 254 and around side wall 241) of thehousing 202 using the "reduced-height" Picatinny rail design discussed above. - If desired, conventional Picatinny
accessory mounting rails 262 can be mounted on the outer surfaces of the side walls of the upper and/orlower parts rails 289, usingapertures 251 ofupper part 204, usingapertures 259 oflower part 206, usingapertures 261 inlateral side walls 241, and/or others). As illustrated in the figures, these can be mounted to corresponding ones of the side walls using, for example, threaded fasteners 264 (e.g., seeFigs. 19B-C ), but it should be understood that they can also be mounted to thehousing 202 using other fastening techniques, such as riveting, adhesive bonding and the like. - As shown in
Fig. 21 ,side walls 241 oflower part 206 includerecesses 207.Recesses 207 may be used to position various types of accessories, such as clamp mounts and/or other devices, onhand guard 200. For example,Fig. 21 illustrates a lighting device 290 (e.g., a SureFire Scout Light in one embodiment) attached to aclamp mount 292.Clamp mount 292 is more clearly shown in the assembled view ofFig. 22 and the exploded view ofFig. 23 . -
Clamp mount 292 may include abolt 293, afirst clamp member 294, aroll pin 295, asecond clamp member 296, awasher 297, asplit lock washer 298, and anut 299.Clamp mount 292 may be installed on aside wall 241 using slots 254 in a similar manner as described with regard to mountingbracket 201. For example, rotation ofnut 299 may cause first andsecond clamp members flange 296A ofsecond clamp member 296 to extend aroundside wall 241. - As shown in
Fig. 22 , whenclamp mount 292 is assembled, ashank 293A ofbolt 293 is exposed.Recesses 207 inside walls 241 may be configured (e.g., having substantially scalloped and/or rounded interior surfaces complimentary toshank 293A) to receive shank 294A whileclamp mount 292 is installed. Such engagement of arecess 207 with shank 294A permits clampmount 292 to be conveniently and rapidly positioned at one or more predetermined positions along (e.g., relative to)side wall 241. Other configurations ofrecesses 207 and clamp mounts 292 may be used where appropriate. - A third example embodiment of a
hand guard 300 and associated handguard mounting assembly 302 in accordance with the present disclosure are illustrated in the upper, front and left side perspective view ofFig. 24 , wherein a receiver and rear stock of an associated firearm are omitted for purposes of illustration.Fig. 25 is an upper, front, left side perspective view of the thirdexample hand guard 300 ofFig. 24 , in which the mountingassembly 302, thebarrel 24 andslip ring 40/328 of the associated firearm, and anaccessory mounting rail 304 coupled to a front end portion of a side wall of thehand guard 300 have been omitted for purposes of illustration.Figs. 26A - 26E are top plan, front end elevation, left side elevation, rear end elevation, and bottom plan views of the thirdexample hand guard 300, respectively. - As can be seen in these figures, the third
example hand guard 300 includes many of the same features present in the first and secondexample hand guards tubular housing 306 having open front andrear ends accessory mounting rail 312. As in the above embodiments, the mountingrail 312 can include a rearwardly extending "tail piece" orprotrusion 314 that overlies a front portion the receiver (not illustrated) of the associated firearm and forms an continuation of a similar mounting rail disposed on the upper surface of the receiver, as illustrated in the example embodiment of, e.g.,Fig. 10 . - In the particular example embodiment illustrated, the
tubular housing 306 can, in one embodiment, comprise a single piece that is fabricated, for example, as an extrusion of, e.g., an aluminum alloy, e.g., 6061, that is subsequently machined to form such accessory mounting features astransverse lands 316,grooves 318, and various through-apertures 320 of desired shapes and sizes. It can then, for example, be hard anodized otherwise finished or coated to provide robust corrosion protection. In some embodiments, thetubular housing 306 can be polygonal in cross-section, e.g., octagonal, so as to provide a plurality of generally flat side walls for the mounting of a variety of firearm accessories, or as illustrated inFig. 24 , anaccessory mounting rail 304, such as a Picatinny rail, upon which an accessory, e.g., a light, a telescopic sight, or the like can be mounted. - Alternatively, the
tubular housing 306 can comprise two or more components that are assembled together during manufacture (e.g., welded together), or assembled together with, e.g., fasteners, to form thetubular structure 306, such as the first andsecond hand guards Figs. 6 and16 , respectively. - Advantageously,
housing 306 includesvarious apertures housing 306, and further includesrecesses 307 andrail 312. As a result, a variety of accessories and/or additional rails may be mounted tohousing 306 usingapertures 309,apertures 311, recesses 307, and/orrail 312 in many convenient and flexible orientations (e.g., around the entire perimeter of housing 306), for example, in accordance with the various techniques described herein. - The third
example hand guard 300 is coupled to the associated firearm in a manner that differs from the first andsecond hand guards hand guard 300 is mounted using the handguard mounting assembly 302. As illustrated in, e.g.,Fig. 24 , the mountingassembly 302 couples to a rear end portion of thetubular housing 306 of thehand guard 300. In particular, as will be seen from the discussion below, the thirdexample hand guard 300 is cantilevered forwardly from a front end of the receiver of the associated firearm (not illustrated) by the mountingassembly 302, and through the agency of abarrel nut 326 of the firearm discussed below, such that thebarrel 24 of the firearm is disposed concentrically within the lumen of thetubular housing 306 and such that no contact is made between thehousing 306 and thebarrel 24. - This type of mounting is particularly advantageous in that, since no contact of any kind is made between the
barrel 24 and thetubular housing 306 of thehand guard 300, thehand guard 300 cannot exert any undesirable bending or torsional stresses on thebarrel 24 which could adversely affect the accuracy of the firearm. In this regard, thehand guard 300 is permitted to surround and "float" proximate to thebarrel 24. As a result, even if thehand guard 300 receives external forces (e.g., when pushed upwardly at the front end while supported from the ground or a structure), such forces will not bias thebarrel 24, and sighting accuracy can be maintained. As another example, thermal expansion of the firearm will not cause thehand guard 300 to shift, thus maintaining the accuracy of aiming devices attached to thehand guard 300. -
Fig. 27 is an enlarged partial cross-sectional view of the thirdexample hand guard 300 and the mountingassembly 302 therefor in accordance with the present disclosure, as seen along the lines of the section 27 - 27 taken inFig. 24 . In the particular example embodiment ofFig. 27 , the mountingassembly 302 comprises an annularbarrel nut interface 322 and awedge ring 324, which are both illustrated in more detail inFigs. 35A - 35D and 36A - 36D , respectively. Also seen inFig. 27 are various features with which the mountingassembly 302 interfaces, viz., abarrel nut 326 and a slip ring 328 (e.g., also referred to as a "D ring" or "Delta ring", which in some embodiments may be similar toslip ring 40 discussed here), which are illustrated in more detail inFigs. 37A - 37D and38A - 38D , respectively. Theslip ring 328 is biased forwardly on thebarrel nut 326 and relative to the receiver of the firearm by a slip-ring spring 330, which is disposed concentrically within theslip ring 328 and about thebarrel nut 326 and retained in place by asnap ring 332, illustrated inFig. 40 . - As can be seen in, e.g.,
Fig. 27 , the mountingassembly 302 couples concentrically to a rear end portion of thetubular housing 306, which is effected through a plurality of threadedfasteners 334, each of which extends radially inward through corresponding through-holes in thebarrel nut interface 322 engages in corresponding threadedreceptacles 336, e.g., swage nuts, retained in thetubular housing 306. Advantageously, such radial orientation offasteners 334 reduces the likelihood of them becoming loose during repeated or sustained weapon fire (e.g., in contrast to certain prior longitudinally-secured hand guards which may be susceptible to loosening in response to repeated forward and rearward movement of the weapon during firing). - In the particular embodiment illustrated, three
fasteners 334 andcorresponding receptacles 336, respectively located on the two lateral sides and the bottom side of thetubular housing 306, are used to couple the mounting assembly to thetubular housing 306. In various embodiments, the handguard mounting assembly 302 may attach to the receiver of the host firearm first, and then thetubular housing 306 may attach to the mountingassembly 302, or alternatively, the mountingassembly 302 may attach to thetubular housing 306 first, then the mountingassembly 302 may attach to the receiver of the host firearm, whichever is more convenient. -
Fig. 37A is an upper and left side perspective view of thebarrel nut 326 utilized in the host firearm and with which the exampletubular housing 306 and handguard mounting assembly 302 interface.Fig. 37B is a front end elevation view of thebarrel nut 326,Fig. 37C is a left side elevation view thereof, andFig. 37D is a rear end elevation view thereof. As may be seen in these figures, thebarrel nut 326 comprises an elongated,annular barrel portion 333, which is internally threaded to receive complementary external threads on the host firearm, and aflange 335 that extends radially outward disposed on a front end thereof. As can be seen in, e.g.,Figs. 37A - 37D , theflange 335 includes afront face 338, arear face 340, a plurality of teeth (e.g., tines) 342 extending radially outward from it, and a plurality of arcuate scallops 344 (e.g., also referred to as key ways) extending radially into it and alternating with respective ones of thetines 342. Also seen in, e.g.,Figs. 37A and 37C is acircumferential channel 346 within which thesnap ring 332 that retains theslip ring spring 330 is installed. Theradial tines 342 andscallops 344 are arranged in a rotationally symmetrical fashion about a centerline of theflange 335 andbarrel nut 326, and hence about the centerline of thebarrel 24. - As discussed above in connection with
Fig. 1A , gas operated firearms of the types contemplated herein employ a gas tube 30 (shown in dashed outline in, e.g.,Figs. 30, 31 ) that conveys combustion gases from a port in thebarrel 24 located in a distal portion of thebarrel 24 to the receiver of the firearm, which are used by components in the receiver for the automatic actuation of the firearm when it is fired. Thegas tube 30, like thebarrel 24 andbarrel nut 326, extends forwardly from the center of the receiver at a 12 o'clock position, i.e., disposed above the centerline of barrel of the firearm. Thescallops 344 in theflange 335 of thebarrel nut 326 are semicircular and have a diameter about the same as thegas tube 30. Thus, as seen in, e.g.,Figs. 37B and 37D , thegas tube 30 can be used as an "index" to orient the rotational position of thebarrel nut 326 and thebarrel 24 of the firearm relative to its receiver by installing thebarrel nut 326 such that thegas tube 30 nests radially within one of thescallops 344 of theflange 335. In this arrangement, a vertical orsagittal plane 348 through the centerline of thebarrel 24 bisects thegas tube 30, thebarrel 24, thebarrel nut interface 322, thewedge nut 324, thebarrel nut 326, and thetubular housing 306. Additionally, it should be noted that each of the foregoing structures are disposed concentric to the centerline of thebarrel 24 in some embodiments. -
Fig. 35A is an upper and left side perspective view of abarrel nut interface 322 of the example handguard mounting assembly 302.Fig. 35B is a front end elevation view of thebarrel nut interface 322,Fig. 35C is a left side elevation view thereof, andFig. 35D is a rear end elevation view thereof. As can be seen in these figures, thebarrel nut interface 322 comprises a generally annular structure having aflange 350 extending radially inward at arear end 352 thereof. Theinternal flange 350 of thebarrel nut interface 322 defines a forward facing transverse surface comprising a plurality of substantiallysemicircular tabs 354 extending radially inward and substantially conforming in size, shape, and location to thescallops 344 of thebarrel nut 326. - As may be seen in, e.g.,
Fig. 35B , selected ones of thesetabs 354 includeindentations 356 formed in the forward facing surface of thetabs 354. Theindentations 356 are configured to receive a corresponding one of thetines 342 on theflange 335 of thebarrel nut 326 longitudinally, i.e., in a front-to-rear direction, in a manner described in more detail below. In the particular embodiment illustrated inFigs. 30 and35B , there are four suchlongitudinal indentations 356, each formed in a respective one of thetabs 354. In some embodiments, the number ofindentations 356 and/or the number oftabs 354 can be varied, including up to oneindentation 356 pertab 354. - Also, as may be noted in
Figs. 35B and 35D , theflange 350 at the rear of thebarrel nut interface 322 includes acutout 358 configured to clear thegas tube 30 extending forwardly from the receiver at the 12 o'clock position thereon. Additionally, as can be seen in, e.g.,Figs. 35A and 35C , thebarrel nut interface 322 includes four circumferentially distributed, radially extending threadedreceptacles 360, each of which is configured to receive a corresponding one of four setscrews 374, which, as described in more detail below, are used both to retain thewedge ring 324 concentrically within thebarrel nut interface 322 and to advance thewedge nut 324 longitudinally toward the forward facing surface of theflange 350 of thebarrel nut interface 322. Similar tofasteners 334, the radial orientation ofset screws 374 reduces the likelihood of them becoming loose during repeated or sustained weapon fire. -
Fig. 36A is an upper and left side perspective view of thewedge ring 324 of theexample mounting assembly 302.Fig. 36B is a front end elevation view of theexample wedge ring 324,Fig. 36C is a left side elevation view thereof, andFig. 36D is a rear end elevation view thereof. Thewedge ring 324 comprises a generally annular structure that includes a central bore through which thebarrel 24 of the host firearm extends and anarcuate space 362 in its circumfery that, like thecutout 358 in theflange 350 of thebarrel nut interface 322, is adapted to clear thegas tube 30 when thewedge ring 324 is disposed in its operating position. - As can be seen in
Figs 36C and 36D , thewedge ring 324 includes a rearward facingtransverse surface 364 having a plurality of rearwardly extendinglands 366 disposed thereon, each substantially conforming in size, shape and location to one of thescallops 344 in theflange 335 of thebarrel nut 326. In the particular example embodiment illustrated, there are four rearwardly extendinglands 366 disposed in a bilaterally symmetrical relationship relative to a sagittal plane of thewedge ring 324, but as in the case of theindentations 356 in theflange 350 of thebarrel nut interface 322, the number and angular positions of thelands 366 can be varied within limits, such that they substantially align with a corresponding one of thescallops 344 in theflange 335 of thebarrel nut 326 when thewedge ring 324 is disposed in its clamping position described below. - Additionally, the
wedge ring 324 includes a plurality, e.g., four, L-shaped mounting and clamping adjustment features 368 extending forwardly from a front surface thereof. Each L-shapedfeature 368 comprises aplane 370 that is inclined relative to both the longitudinal and radial directions and aradially extending leg 372 disposed forwardly of theinclined plane 370. As illustrated in, e.g.,Fig. 32 , theinclined plane 370 andradial leg 372 act in cooperation with acorresponding set screw 374 extending in a radial direction through a corresponding one of the four threadedreceptacles 360 in the sides of thebarrel nut interface 322 described above to: retain thewedge ring 324 concentrically within thebarrel nut interface 322 and; when theset screws 374 are advanced radially inward against corresponding ones of theinclined planes 370, to urge the rearward facingtransverse surface 364 of thewedge ring 324 rearwardly, in the direction of thearrow 377 inFig. 32 , and against thefront face 338 of theflange 335 of thebarrel nut 326 so as to clamp theflange 335 firmly between the rearward facingsurface 364 of thewedge ring 324 and the forward facing surfaces of thetabs 354 of thebarrel nut interface 322. - Thus, in one embodiment, the
set screws 374 in thebarrel nut interface 322 can be backed out of theirreceptacles 360 until the body of thewedge ring 324 and the tops of theradial legs 372 clear the ends of the set screws 374. Thewedge ring 324 can then be inserted longitudinally forward in thebarrel nut interface 322 such that thewedge ring 324 is disposed generally concentrically within thebarrel nut interface 322, thearcuate space 362 in the circumfery of thewedge ring 324 is generally aligned withcutout 358 thegas tube 30 in the rear end of thebarrel nut interface 322 and each of theinclined planes 370 is disposed below a corresponding one of the set screws 374. Theset screws 374 can then be advanced radially within theirrespective receptacles 360 in thebarrel nut interface 322 until their ends contact a corresponding one of theinclined planes 370, at which point thewedge ring 324 is retained concentrically within thebarrel nut interface 322 and the handguard mounting assembly 302 is prepared for assembly to the host firearm. - A
slip ring 328 of a type employed on the host firearms contemplated herein is illustrated in the upper and left side perspective view ofFig. 38A. Fig. 38B is a front end elevation view of theslip ring 328,Fig. 38C is a left side elevation view thereof, andFig. 38D is a rear end elevation view thereof. As can be seen in the figures, theslip ring 328 comprises an annular, generally frusto-conical structure having a stepped circumferential surface. As can be seen in, e.g.,Figs. 38B and 38D , theslip ring 328 includes anotch 329 similar to thecutout 358 in the rear end of thebarrel nut interface 322 and thearcuate space 362 in the circumfery of thewedge ring 324 that is configured to clear the gas tube 30 (shown in dashed outline) extending forwardly from the receiver of the host firearm. - The
slip ring spring 330 used to bias theslip ring 328 forwardly on thebarrel nut 326 is illustrated in the upper and left front perspective, left side elevation, rear end views thereof ofFigs. 39A - 39C , respectively, andFig. 40 is a front end elevation view of asnap ring 332 used to retain theslip ring spring 330 on thebarrel nut 326 and behind a flange at the front end of theslip ring 328. - Following is a description of an example method for attaching the
hand guard 300 to a host firearm using the example handguard mounting assembly 302. In this example, it is assumed that abarrel 24,barrel nut 326, andslip ring 328 extend longitudinally forward from a receiver of the host firearm. In this regard, thehand guard 300 may be attached to the firearm without requiring removal ofslip ring 328. - An elongated
tubular housing 306 having a lumen extending between opposite ends of the housing of the type described above and illustrated in, e.g.,Figs. 26A - 26E , is provided. As discussed, in some embodiments, the handguard mounting assembly 302 is coupled to a rear end portion of thehousing 306, using, e.g., a plurality of radially extending fasteners 334 (e.g., extending radially inward toward thebarrel 24 of the firearm) of the type described herein. - A distal end of the
barrel 24 of the firearm is then inserted through the rear end of the mountingassembly 302 and into the lumen of thetubular housing 306 such that therear end 352 of thebarrel nut interface 322 is disposed in flush abutment with a front end of theslip ring 328 of the firearm (seeFigs. 27 and33 ), thebarrel 24 is disposed concentrically within the lumen of the housing 303, and thegas tube 30 of the firearm is disposed within thecutout 358 in therear end 352 of thebarrel nut interface 322 and thearcuate space 362 in the circumfery of thewedge nut 324. - The mounting
assembly 302 is then advanced longitudinally rearward against theslip ring 328 and the bias of theslip ring spring 330 such that thetabs 354 of thebarrel nut interface 322 pass through respective ones of thescallops 344 of theflange 335 of thebarrel nut 326, therear face 340 of theflange 335 on thebarrel nut 326 is disposed forward of the forward facing surface of thetabs 354 on thebarrel nut interface 322, and thefront face 338 of theflange 335 is disposed rearward of the rearward facingsurface 364 of thewedge ring 324. - The mounting
assembly 302 is the rotated circumferentially relative to the receiver of the firearm (e.g., rotated around the barrel 24) until theaccessory mounting rail 312 on the upper surface of thetubular housing 306 is aligned substantially perpendicular to asagittal plane 348 extending through a centerline of thebarrel 24 of the firearm, thetines 342 on theflange 335 of thebarrel nut 326 are aligned radially with corresponding ones of theindentations 356 in the forward facing surfaces of thetabs 354 of thebarrel nut interface 322, and lands 366 on therearwardly facing surface 364 of thewedge ring 324 are aligned radially with corresponding ones of thescallops 344 in theflange 335 of thebarrel nut 326. - At this point, the rearward force applied to mounting
assembly 302 against theslip ring 328 can be relaxed so as to allow the bias of theslip ring spring 330 to urge the mountingassembly 302 longitudinally forward untiltines 342 on theflange 335 of thebarrel nut 326 are received within corresponding ones of theindentations 356 in the forward facing surfaces of thetabs 354 of thebarrel nut interface 322, and lands 366 on therearwardly facing surface 364 of thewedge ring 324 are received longitudinally within corresponding ones of thescallops 344 in theflange 335 of thebarrel nut 326, thereby locking the mountingassembly 302 andtubular housing 306 against any further, undesirable rotation relative to thebarrel 24 and/or the receiver of the firearm. For example,Fig. 34 illustratesbarrel nut interface 322,wedge ring 324, andbarrel nut 326 in a locked position. - The
set screws 374 in thebarrel nut interface 322 can then be tightened in a radially inward direction and against corresponding ones of theinclined planes 370 of thewedge ring 324, thereby clamping theflange 335 of thebarrel nut 326 firmly between the rearward facingsurface 364 of the wedge ring and the forward facing surfaces oftabs 354 of thebarrel nut interface 322. As discussed above, when theflange 335 of the barrel nut has been firmly clamped between the opposing surfaces of thewedge ring 324 and thebarrel nut interface 322, thehand guard 300 is cantilevered forwardly from the front of the receiver of the firearm, with thebarrel 24 disposed concentrically within the lumen of thetubular housing 306, and as discussed above, is prevented from moving, either longitudinally or rotationally relative to thebarrel 24 or receiver. - As discussed above, in some embodiments, the
tubular housing 306 can provide one or more generally flat side walls for the mounting of a variety of firearm accessories, or as illustrated inFig. 24 , anaccessory mounting rail 304, such as a Picatinny rail, upon which a firearm accessory, e.g., a light, a telescopic sight, or the like can be mounted.Fig. 41 is a partial top plan view ofaccessory mounting rail 304 shown mounted to theexample hand guard 306 ofFig. 24 in accordance with the present disclosure, as seen along the lines of the section 41 - 41 taken therein.Fig. 42A is a top plan view of the exampleaccessory mounting rail 304,Fig. 42B is a left side elevation view thereof,Fig. 42C is a bottom plan view thereof, andFig. 42D is a right side elevation view thereof. - As can be seen in these figures, the example
accessory mounting rail 304 comprises anelongated body 381, which in one embodiment, can comprise an extrusion, that is coupled to the associatedtubular housing 306 by means of a pair of fasteners 382 (e.g., quarter turn or half turn fasteners in some embodiments) that extend intocorresponding apertures 320 in thehousing 306. -
Fig. 43A is a cross-sectional view of theaccessory mounting rail 304 and anexample fastener 382 used to fasten it to theexample hand guard 300, as seen along the lines of the section 43 -43 taken inFig. 42C .Fig. 43B is a cross-sectional view of theaccessory mounting rail 304 and theexample fastener 382, as seen along the lines of the section 43 -43 taken inFig. 42C while the accessory mounting rail is attached to thehousing 306 ofhand guard 300.Fig. 44A is a top plan view of thefastener 382,Fig. 44B is a left side elevation view thereof, andFig. 44C is a bottom plan view thereof. - As can be seen in these figures, the
fastener 382 comprises ashaft 383 rotatably retained within a bore extending through thebody 381 of theaccessory mounting rail 304. As illustrated inFigs. 42D and43 , eachshaft 383 can be rotatably retained in thebody 381 of therail 304 by aset screw 384 having aball bearing 385 rollably disposed at an internal end thereof to permit easy rotation of theshaft 383 within its associated bore. Thefastener 382 is provided with ahead 386 formed at a proximal end of theshaft 383, and thehead 386 includes arecess 387 configured to receive a tool for turning theshaft 383. In the particular embodiment illustrated in the figures, therecess 387 comprises a narrow slot having an arcuate bottom that is adapted to receive the edge of a coin, such as a dime, penny, nickel, and/or quarter, and/or a screwdriver. An oval shapedfoot 388 is fixed against rotation relative to theshaft 383 at a proximal end thereof by, e.g., aroll pin 390. - In some embodiments, the installation of the rail 380 on the
tubular housing 306 of thehand guard 300 involves aligning the long dimension of theheads 386 and theoval feet 388 of thefasteners 382 along the long dimension of thebody 381. In this configuration, therail 304 is placed at the desired longitudinal position on a flat surface of thetubular housing 306 and respective ones of theoval feet 388 of thefasteners 382 are inserted throughcorresponding apertures 320 in thehousing 306. Theheads 386 of thefasteners 382 are then turned until theheads 382, and hence theoval feet 388 of the fasteners are disposed perpendicular to the long axis of thebody 381, and the upper surfaces of theoval feet 388 are engaged with the inner wall surfaces of thehousing 306. As shown inFigs. 43A-B , in some embodiments, aBelleville disk spring 391 may be provided to bias thefastener 382 outward (e.g., by pushinghead 386 downward against aninside surface 305 ofhousing 306 inFig. 43B ), to clamp on tohousing 306. -
Fig. 45 is an upper, front, left side perspective view of anotherexample hand guard 400 of a type similar to that ofFig. 24 , in accordance with the present disclosure. As may be seen inFig. 45 , theexample hand guard 400 includes many of the same features and mounting capabilities as the thirdexample hand guard 300 described above, except that it has ahousing 406 that is shorter in length thanhousing 306, and therefore adapted to firearms havingshorter barrels 24, e.g., an M4 carbine rifle. Accordingly, the various hand guards of the present disclosure may be modified as appropriate for use with various types and lengths of weapons. Moreover, any of the various features set forth in the present disclosure (e.g., with regard to the various hand guards and mounting hardware) may be combined with each other, in whole or in part, as may be desired for various applications. - The foregoing description is presented so as to enable any person skilled in the art to make and use the invention. For purposes of explication, specific nomenclature has been set forth to provide a thorough understanding of the disclosure. However, it should be understood that the descriptions of specific embodiments or applications provided herein are provided only by way of some example embodiments of the invention, and not by way of any limitations thereof. Indeed, various modifications to the embodiments will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other embodiments and applications without departing from the scope of the invention. Thus, the present invention should not be limited to the particular embodiments illustrated and described herein, but rather, should be accorded the widest possible scope consistent with the claims.
Claims (14)
- A hand guard (100) for a firearm (10) of a type that includes a barrel (24) and a barrel nut (326) extending longitudinally forward from a receiver (12) of the firearm (10), the hand guard (100) comprising:an elongated tubular housing (102) having a lumen (112) extending between opposite ends of the housing (102);a mounting assembly (302) coupled concentrically to a rear end portion of the housing (102), the mounting assembly (302) including a pair of opposing transverse surfaces (364) respectively disposed on opposite sides of a transverse flange (243) located on a front end of the barrel nut (326), at least one of the transverse surfaces being longitudinally moveable toward the other transverse surface so as to clamp the flange (243) firmly between the two transverse surfaces and such that the barrel (24) of the firearm (10) is disposed concentrically within the lumen (112) of the housing (102);a mechanism for adjustably urging the at least one transverse surface longitudinally toward the other transverse surface; andwherein:the flange (335) of the barrel nut (326) includes at least one tine (342) extending radially outward from it, characterised in that a forward facing one of the transverse surfaces comprises a barrel nut interface (322) and includes at least one indentation configured to receive the at least one tine (342) longitudinally therein, orthe flange (335) of the barrel nut (326) includes at least one scallop (344) extending radially into it, and a rearward facing one of the transverse surfaces comprises a wedge ring (324) and includes at least one rearwardly extending land (316) configured to engage longitudinally within the at least one scallop (344).
- The hand guard (100) of claim 1, wherein the urging mechanism comprises:an inclined plane disposed in front of a rearward facing one of the transverse surfaces; anda radially extending set screw (374) disposed above the inclined plane and arranged to urge the rearward facing transverse surface longitudinally toward the other transverse surface when an end of the set screw (374) is radially advanced against the inclined plane.
- The hand guard (100) of claim 1, wherein the tubular housing (102) comprises an extrusion, and/or comprises an aluminum alloy, and/or includes at least one side wall defining a firearm accessory mounting rail (113), and/or is polygonal in cross-section.
- The hand guard of claim 3, wherein the tubular housing (102) has a generally octagonal cross-section.
- The hand guard of claim 1, whereinthe tubular housing (102) includes at least one radially extending threaded aperture (120) disposed in the rear end portion thereof, andthe mounting assembly (302) is coupled to the tubular housing (102) by at least one threaded fastener extending radially through the mounting assembly (302) and into the at least one threaded aperture (120).
- A method for attaching a hand guard (100) to a firearm (10) of a type that includes a barrel (24) and a barrel nut (326) extending longitudinally forward from a receiver (12) of the firearm (10), the method comprising:providing an elongated tubular housing (102) having a lumen (112) extending between opposite ends of the housing (102); andcoupling a hand guard mounting assembly (302) to a rear end portion of the housing (102), the hand guard mounting assembly (302) including:an annular barrel nut interface (322) having a flange (354) extending radially inward at a rear end thereof;the flange (354) defining a forward facing surface comprising at least one tab (354) extending radially inward and conforming in size, shape and location to at least one scallop (344) extending radially inward into a flange (335) located on a front end of the barrel nut (326);the forward facing surface of the at least one tab (354) having at least one indentation configured to receive a tine (342) extending radially outward from the flange longitudinally therein; anda wedge ring (324) disposed concentrically within the barrel nut interface (322), the wedge ring (324) defining a rearward facing surface having at least one rearwardly extending land (316) disposed thereon, the at least one land conforming in size, shape and location to the at least one scallop (344) of the flange, and at least one inclined plane disposed on the wedge ring (324) in front of the rearward facing surface and below at least one radially extending set screw (374) disposed in the barrel nut interface (322).
- The method of claim 6, further comprising:inserting a distal end of the barrel (24) of the firearm (10) through a rear end of the mounting assembly (302) and into the lumen (112) of the tubular housing (102) such that the rear end of the barrel nut interface (322) is disposed in abutment with a front end of a slip ring (328) of the firearm (10) and the barrel (24) is disposed concentrically within the lumen (112);advancing the mounting assembly (302) longitudinally rearward against the bias of the slip ring (328) such that the at least one tab (354) of the barrel nut interface (322) passes through the at least one scallop (344) of the flange of the barrel nut (326), a rear face of the flange of the barrel nut (326) is disposed forward of the forward facing surface of the tabs of the barrel nut interface (322), and a front face of the flange is disposed rearward of the rearward facing surface of the wedge ring (324);rotating the mounting assembly (302) circumferentially relative to the receiver (12) of the firearm (10) until an accessory mounting rail (304) on an upper surface of the tubular housing (102) is aligned substantially perpendicular to a sagittal plane extending through a centerline of the barrel (24) of the firearm (10), the at least one tine (342) on the flange (335) of the barrel nut (326) is aligned radially with the at least one indentation in the forward facing surface of the at least one tab (354) of the barrel nut interface (322), and the at least one land (316) on the rearwardly facing surface of the wedge ring (324) is aligned radially with the at least one scallop (344) of the flange (335) of the barrel nut (326); andallowing the bias of the slip ring (328) to urge the mounting assembly (302) longitudinally forward until the at least one tine (342) is received longitudinally within the at least one indentation, and the at least one land (316) is received longitudinally within the at least one scallop (344).
- The method of claim 7, further comprising advancing the at least one set screw (374) in the barrel nut interface (322) in a radially inward direction and against the at least one inclined plane of the wedge ring (324) and thereby clamping the flange (335) of the barrel nut (326) firmly between the rearward facing surface of the wedge ring (324) and the forward facing surface of the barrel nut interface (322).
- The method of claim 6, wherein the coupling comprises:providing at least one receptacle (336) for a fastener (334) in a rear end portion of the tubular housing (102); andadvancing at least one fastener (334) through an aperture in the barrel nut interface (322) and into the at least one fastener receptacle (336) of the tubular housing (102).
- The method of claim 6, further comprising coupling an accessory mounting rail (304) to a longitudinal surface of the tubular housing (102).
- The method of claim 10, wherein the accessory mounting rail (304) comprises a Picatinny rail.
- The method of claim 10, wherein the coupling comprises using at least one a quarter turn fastener.
- The method of claim 12, wherein the at least one quarter turn fastener comprises:a shaft (383) rotatably retained within a bore through the accessory mounting rail (304);a generally planar head formed at a proximal end of the shaft (383), the head including an indentation (356) configured to receive a tool for turning the shaft (383); andan oval shaped foot fixed against rotation at a proximal end of the shaft (383).
- The method of claim 13, wherein the indentation (356) is configured to receive the edge of a coin.
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US201461925924P | 2014-01-10 | 2014-01-10 | |
US14/578,229 US9476672B2 (en) | 2012-04-20 | 2014-12-19 | Accessory mounting hand guard for firearm |
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EP2896927A1 EP2896927A1 (en) | 2015-07-22 |
EP2896927B1 EP2896927B1 (en) | 2016-12-14 |
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USD923129S1 (en) | 2017-06-08 | 2021-06-22 | Springfield, Inc. | Free floating handguard anchoring system |
US10401122B2 (en) | 2017-06-08 | 2019-09-03 | Springfield, Inc. | Free floating handguard anchoring system |
US10724825B2 (en) * | 2017-11-29 | 2020-07-28 | Occam Defense Solutions Inc. | Handguard system for firearms |
DE102022110346B4 (en) | 2022-04-28 | 2024-06-13 | C. G. Haenel GmbH | Firearm and arrangement for attaching a handguard |
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US6895708B2 (en) * | 2003-05-29 | 2005-05-24 | Surefire, Llc | Accessory mounts for firearms |
US8069604B2 (en) * | 2004-07-29 | 2011-12-06 | Larue Mark C | Hand-guard / barrel nut clamp assembly for tactical firearm |
US8336243B2 (en) * | 2007-04-09 | 2012-12-25 | Colt Defense Llc | Firearm having a removable hand guard |
US7716865B2 (en) * | 2006-05-24 | 2010-05-18 | Daniel Defense, Inc. | Systems and methods for providing a hand guard and accessory mounting device for a firearm |
US7712242B2 (en) | 2006-12-27 | 2010-05-11 | Surefire, Llc | Rail clamp mount |
EP2191224B1 (en) * | 2007-09-20 | 2015-05-20 | Daniel Defense, Inc. | Systems and methods for installing a hand guard on a firearm |
US8276303B2 (en) * | 2009-04-30 | 2012-10-02 | Smith & Wesson Corp. | Firearm hand guard rail system |
US8578642B2 (en) * | 2011-05-09 | 2013-11-12 | Troy Industries, Inc. | Drop-in handguard system |
US9127906B2 (en) * | 2012-04-20 | 2015-09-08 | Surefire, Llc | Accessory mounting hand guard for firearm |
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