US2390738A - Grenade launcher - Google Patents

Description

Dec. 11, 1945. P. B. RUTHERFORD ET AL. 2,390,738

GRENADE LAUNCHER Filed June 25, 1943 5 Sheets-Sheet l Dec. 1l, 1945. P. B, RUTHl-:RFORD ETAL 2,390,738

GRENADE LAUNCHER Filed June. 25, 1943 3 Sheets-Sheet 2 l., Il ,l Il 11'/ /A/VEA/TORS 7o/VAL@ f?. 0575/? PETER .BHUTHERFORD AGENT Dec. 1l, 1945. P. B. RUTHERFORD ET Al. 2,396,738

GRENADE LAUNCHER Filed June 25, 1943 3 Sheets-Sheet 3 Patented Dec. 11, 1945 NITED STATES TENT OFFICE GRENADE LAUNCHER tion of Delaware Application June 25, 1943, Serial No. 492,254

(Cl. L12-1) 6 Claims.

This invention relates, in general, to firearms, and, in particular, to a grenade launcher adapted to be used on an automatic gas operated rifle of the type illustrated in the Garand patent, No. 2,287,032.

An object of the invention is to launch a grenade from the rifle barrel using the pressure of powder gases transmitted entirely through the barrel. A further object is to provide an automatic gas operated riile with a grenade launcher which is secured to the end of the rifle barrel by clamping the launcher to the rear edge of the front sight mounting. A still further object is to adapt an automatic gas operated firearm for launching grenades by providing the gas cylinder with a gas valve which is automatically held open by the grenade launcher when the latter is secured on the end of the rie barrel.

Other objects, features and advantages of the invention will be more fully described in the following specification which is descriptive of an exemplary embodiment of the invention. It will be understood, however, that the invention may be modified Within the scope of the appended claims for use with firearms of other types than that shown in the drawings.

In the drawings:

Fig. 1 is a side elevation partly in section of the grenade launcher of this invention secured on the end of a rifle barrel.

Fig. 2 is a plan view in section of the launcher shown in Fig. 1.

Fig. 3 is a plan View in section of the launcher showing a grenade supported thereon.

Fig. 4 is an end elevation of the launcher on line 4-4 of Fig. 1 showing the clamp in elevated position.

Fig. 5 is a sectional plan View of the gas valve and adapter on line 5 5 of Fig. 1.

Fig. 6 is a perspective View of one of the straps having the clamp thereon.

Fig. 7 is a sectional side elevation of the friction. cup of the launcher.

Fig. 8 is an end view ofk a gas cylinder valve screw for use in the gas cylinder of a rearm mounting the launcher.

Fig. 9 is a side elevation in section of the valve screw shown in Fig. 8.

Fig. 10 is an end View of a modification of the gas valve shown in Fig. 8.

Fig. 11 is a side elevation in section of the modied gas valve screw.

Fig. 12 is a perspective view of a modified form of grenade launcher.

Fig. 13 is a plan view of a modified type of strap for connecting the launcher to the rear edge of the front sight.

Referring to Fig. 1, the grenade launcher of this invention is shown mounted on the barrel I5 of a rearm which, for the purposes of illustration, is of the type described in the above identied Garand patent and comprises a gas cylinder i6 provided with an integral rear band I'I and a front band I8, whereby the cylinder is supported on the underside of the barrel. A suitable retaining member I9 is shown threadedly secured on the front or muzzle end of the barrel and is adapted to abut the front edge of the band I8 of the gas cylinder so as to hold the band in place on the barrel. The band I8 is located adjacent a gas port 2U of the barrel and is provided with a gas inlet 22 which is in alignment with the gas port 29. Normally, a standard gas cylinder lock screw (not shown) is mounted through an aperture 23 of the retaining member I9 and is threaded in the front end of the gas cylinder to form both a removable closure therefor and a coupling for connecting the end of the cylinder to the retaining member I9.

In the present invention, however, the lock screw is not used and a suitable gas cylinder valve screw is substituted therefor which serves both as a coupling for the gas cylinder and retaining member and as means for enabling the escape of gas from the barrel in the manner and for the purposes hereinafter described.

The front band I8 constitutes a mounting for a front sight, indicated generally at 24, the latter being secured to the band I8 by a dove-tail connection comprising a transversely disposed dovetail tongue 25 and slot 26 adapted to receive complementary parts of the front sight.

The improved grenade launcher, indicated generally at 21, is adapted to be readily mounted without the use of tools on the muzzle end of the barrel I5 for supporting a grenade. As shown generally in Figs. 1 and 3, the grenade is typical of a new type developed by the Ordnance Department and comprises a hollow cylindrical tail 28 attached at one end to the container 29 of the explosive charge and having suitable guide vanes 3d at its opposite end.

It will be understood that, when a bullet is shot from the barrel, the gas pressure behind the bullet does not escape into the gas port t act on .the auto slide mechanism until the gas port has been uncovered by the bullet and then covers the barrel muzzle,l and, consequently, the

powder gases which are developed in the barrel prior to discharge of the grenade escape through the gas port and act for a relatively long period of time on the slide actuating mechanism. It has been found that subjecting the slide action mechanism to these hot gases for the longer periods Y eiect greater wear and strain on the mechanismV and` is hazardous. The grenade launcher 21 of this invention provides lmeans for overcomingV these malfunctions.

Referringto Fig. 2, the improved launcher comprises a relatively heavy. Ywalled cylindrical tube 33, the internal diameter of which corresponds to or may be slightly'greater than the boreiofthe barrel l5 and which has a counterbore 34 in'its rear end of a diameter to receive the muzzle of the rifle; and shoulder 35 adapted to abut the end of the muzzle as hereinafter described. l t

The exterior surface of the tube is provided adjacent its rear end with a relatively low annulai' shoulder 33' formed by turning or grinding a'relati'vely narrow bandl 31 ofV slightly less diameter than the original diameter of the tube. This band 31 terminates forwardly in a second annular shoulder 38 which is formed by further reducingthe diameter of the tube throughout the remainder of itslength. The external diameter of the reduced portion 39 thus formed is comparable to the diameter of the rifle barrel and is 'provided adjacent its forward end with an annular shoulder 40 and corresponding neck portion 42 of reducedk diameter.` groove 43 4is cut orY otherwise form-ed in the neck 42V at vthe eXtreme forward end of the tube.

Mounted to make a smooth longitudinally sliding t on the tube 33 is a cylindrical sleeve 44. To this end, the internal diameter of the sleeve 44,"at' its rear en'd, is substantially. equal to the exterior diameter ofthe 'corresponding portion of the tube 33. Moreover, the internal diameter of the sleeve remains the same form the rear endof the sleeve forwardly to a point therein which is 'normally substantially opposite the center of the annular band 31 of the tube 33. At this "point, the internal diameter of the sleeve is decreased by an amount corresponding substantially to the depth of the band 31 so as to form an internal shoulder 45 in theV sleeve whichv is normally located' forwardly'of the shoulder 36 of the tube 33 to enable theY sleeve to move rearwardly relative to the tube, but which is adapted to abut the shoulder 36 to limit the relative movement of the sleeve and tube as hereinafter described. From the shoulder 45, the internal diameterrofv the sleeve remains constant throughout a major portion of its length, but terminates ad- A circumferential jacent the forward end of the sleeve in a shoulder 46 substantially equal in height to the height of the shoulder 38 of the tube 33. The shoulder 45 is formed by an annular restriction 41 of the sleeve adapted to slidingly engage the adjacent reduced portion 39 of the tube 33. As shown in Fig. 2, there is thus formed an annular closed space GS having end Walls defined by the annular shoulders 33 and 45 of the tube and sleeve respectively.

The sleeve and tube are adapted to be maintained in normal relationship by means of a coil spring 49 which is supported on the tube 33 within the annular space 48 and abuts at its opposite ends the shoulders 38 and 46 of the tube and sleeve respectively to hold the respective shoulders 36 and 45 in normal spaced relationship, as shown in Fig. 2. It will be clear, however, that, due to the clearance space between theshoulders 35 and 45, the sleeve may be moved rearwardly on the tube 33 a distance corresponding substantially to the width ofthe annular space between these shoulders. v

The rear end of the sleeve e4 is formed integrally with a yoke member 52 which comprises a substantially rectangular relatively thick plate having rectangular recesess 53 cut in each side to provide bearing elements 54 of a hinge joint. A hole 55 is drilled vertically through each pair of bearing elements to receive a -hinge pintle 56. Mounted -in each recess 53 between the bearing elements 54 is the eye portion 51 of a strap 58 which is pivotally secured to the yoke by a hinge pintle 56.

Each strap comprises a flat strip of metal sub'- `stantia1ly U-shaped in cross section provided .at its rear end with a block 59 which is welded or otherwise fastened in the channel portion of the strap and has a longitudinally disposed semicylindrical-surface 6l) on its inner face conforming substantially to and adapted to embrace the side ofthe-rifle barrel.

The forward edge 62 of each block is suitably bevelled, as shown in Fig. 2, toengage the rear edge of the front sight base or mounting I8 when the straps 58 are closed, as shown in Figs. 2 and 4. Each strap is provided on its upper surface immediately above its barrel embracing block 55 with a substantially flat laterally extending lip Y 63 and 33 respectively, the lip 63 being adapted to overlie and frictionally engage the lip 63' when the straps are closed, see Fig. 4. The for- Ward edges 630 and 630', respectively, of' each lip constitutes, in effect, a cam surface which is 'adapted to cammingly engage behindV the'rear edge of the front sight mounting so as to draw the straps 58 and yoke 52 rearwardly 'with respect to` Vthe barrel, thereby fastening the launcher 21 onto the muzzle end of the gun and taking up any tolerance between the end of the muzzle and the rear edge of the front sight as hereafter described.

Suitable means for locking the straps 38 in closed position is shown in Fig. 6 and comprises a clip 34 which is pivotally secured at one end to one of the straps 58 and is formed at its opposite end with'a U-shaped clasp B5 Vadapted to be swung down over the hook-shaped ends or lips of the closed straps to' hold them securely together. g Y

From the foregoing description, it will .be 'clear that the launcher 21 is mounted` on the gun Ybarrel by inserting the muzzleend of thebarrel I5 into the counterbore 34 of the tube 33 and thereafter swinging the straps '58 together, asv

shown .in Fig. 2, to cammingly engage the front edges 630 .and 630 thereof with the rear edge of the front sight mounting.

`As the straps are squeezed together, the camming action resulting from engagement of the camming surfaces 639 and 630', with the rear edge lof the front sight, draws the yoke 52 and its sleeve 44 rearwardly relative to the tube 33 against the compression force of the coil spring 49. Means are thus provided for drawing the shoulder 35 of the tube 33 tightly into contact with the muzzle end of the barrel. This is an important feature inasmuch as when launching grenades the gas pressure acting on the front of the launcher tends to drive it rearwardly against the end of the barrel; moreover, when Y fir-ing bullets through"thewlauncher, theY recoil force tends to pull the launcher forward against the rear edge of the front sight mounting. By providing the above described resilient mounting, each launcher can thus be securely fastened to a gun muzzle despite tolerances between the end of the muzzle and the rear edge of the front sight. The hook portions 63 and 63 of the straps 58 are locked together behind the rear edge of the front sight mounting as above described, the recoil load being taken by engagement of the front edges B2 of the blocks 59 with the rear edges of the front sight.

Suitable means is provided on the front end of the launcher for releasably retaining the grenade on the sleeve 44 for all elevations of the barrel and comprises a friction cup 96 which, as shown in Fig. 7, is apertured as at 61 to form a sliding t on the reduced portion 39 of the tube 33 adjacent the shoulder 49 and is provided at its rear end with resilient circumferentially spaced fingers 68, four being shown in the present embodiment, which are sprung outwardly slightly so as to frictionally engage the sleeve 28 of the grenade. The friction cup is adapted to abut the shoulder formed by the end 4 of the sleeve 44. A retaining ring 69 is carried on the reduced portion 42 of the tube 33 and abuts the shoulder 4l! thereof, being locked in position by a snap ring which is engaged in the groove 43 of the tube within a counterbore 12 in the front end of the ring 69. Since the outside diameter of the ring 69 is substantially equal to the diameter of the sleeve, the gas pressure developed in the barrel when projecting grenades is transmitted by the ring 69 to the tube 33 and hence to the end of the rifle barrel and substantially none of the gas pressure is enabled to act against the shoulder 44 of the sleeve 44.

Suitably secured to the yoke 52 is a means constructed and arranged to engage and open a valve screw of the type hereinafter described when the launcher is fastened onto the end of the barrel. The valve screw opening means comprises a cylindrical stem 13, see Fig. 5, having a drive t in a centrally located aperture 'I4 of the yoke 52 and provided with an enlarged rearwardly extending head 15.

Secured to the yoke by the stem 13 is an adapter T6. The latter provides means for preventing the shooter from attaching the launcher to a firearm from which the standard gas cylinder lock screw has not been removed and comprises a substantially rectangular block, the longitudinal axis of which is substantially transverse to the longitudinal axis of the barrel and parallel to the horizontal plane of the barrel. The front face of the adapter abuts the rear face of the yoke and is held in engagement therewith by a shoulder l1 of the stem 13 which engages the bottom 18 of a recess 19 formed in the rear face of the adapter.

The recess 19 is substantially rectangular except that its right and left sides 8i) and 82, see Fig. 4, are concave arcs of a circle, the diameter of which is greater than the height of the block and substantially equal to the outside diameter of the gas cylinder valve screw hereinafter described. Moreover, the recess 'I9 is counterbored as at 83 to provide a means for guiding the adapter 'I6 into place.

The gas cylinder valve screw is, as shown in Figs. 5, 8 and 9, adapted to be provided as standard equipment or substituted for the standard lock screw used Yon the above identified rifle when equipping the gun with the grenade launcher. Further, it should be pointed out that, when the gun is equipped with the gas cylinder valve screw, the launcher of this invention may be quickly mounted for firing a grenade or removed and the gun used in the ordinary manner for firing projectiles without making any other alterations in the gun. Moreover, the bayonet may be mounted on the gun even though the gas cylinder valve screw is in place. The valve screw comprises a bushing 84 suitably dimensioned to fit in the lock screw aperture 23 of the retaining member I 9 and is threaded at its rear end to engage in the internally threaded aperture of the front sight mounting I 8. The bushing is provided with a rim 85, the diameter of which corresponds to the diameter of the recess 19 of the adapter 'i6 so as to make a nice t therein when the launcher is secured to the barrel. By making the diameters of the recess 19 and rim 85 slightly less than the outside diameter of the standard type of lock screw, it will be clear that the launcher cannot be mounted on a rifle which is equipped with the usual type of lock screw.

The bushing 84 is provided with a longitudinally drilled bore having a plurality of circumferentially spaced longitudinally extending grooves 8S. four being shown in the present embodiment, which form lands 8l. The grooves 86 constitute gas escape apertures and are in direct communication with a valve seat 88 which is formed on the rear end of the bushing and provided with an annular relief recess 89. The bore i-s counterbored from the front or rim end of the bushing rearwardly a predetermined distance to form shoulders 9E on the four lands 8l. Further, the lands are provided with a second counterbore which terminates in a bevelled shoulder 9| on each land for the purpose hereinafter described.

Slidingly supported on the lands in the rear part of the bushing is a valve member comprising a cylindrical valve stem 92 having a circumferential groove 93 in its front end and a valve head 94 at its opposite end, the latter having a bevelled surface 95 adapted to make a gas tight t on the Valve seat 88 of the bushing. As shown, 5 the valve seat 88 is relieved by the recess 89 so that, in the event carbon is deposited on the surfaces, it will not keep the valve member from seating correctly. Likewise, the counterbcred portions Of the bore provide relief surfaces for the valve stem 92.

Suitable means for retaining the valve member in the bushing comprises an annular snap ring 96 which is sprung into the groove 93 cf the valve stem and is adapted to frictionally engage the counterbored lands 8l and their respective shoulders 9U and 9|. One end 9'! of the ring is adapted to project into one'of the grooves 86 of the bushl ing,r as shown in Fig. 8, to prevent rotation of the ring.

When the valve is closed, as shown in Fig. 9, the snapring S expands into a irictional contact with the bevelled shoulders 9| and thus eiectively holds the valve from jarring open, for it Will be evident that any force tending to move the valve stem rearwardly so as to open the valve will be resisted by the force necessary to compress the snap ring as it rides up the bevelled shoulders 9i of the lands. In accordance with this construction, the valve will be held on its seat at all times unless vpositively opened which occurs when the valve stem is engaged by the above described valve opening stem 'I3 of the launcher. Further, coinplete removal of the valve from the bushing is 4evenmore strongly resisted by engagement of the snap ring with the square shoulders 95 of the lands. Y In the normal use'of the gun, no forces are developed on the valve stem suilcient to project the valve Imember from its bushing.

A modication of the valve screw is shown in Figs.V and 11 and comprises a bushing 98 substantially identical to the bushing 84, but provided with a-bore having a single counterbore forming square shoulders 99 on the lands IGI?. rl'he valve stem .IGI of the valve member is shown provided at its forward end with a small lip or annular square shoulder IZ which is slightly larger in diameter than the diameter of the lands I rearwardly of the shoulders 9S. The valve is assembled by forcing the stem through the smaller end of the bushing until the shoulder IGZ of the stem passes beyond the square shoulder 99 ci the lands. Thereupon the shoulder IGZ expands or recovers slightly suilciently to engage the shoulders 9d to prevent the valve member from dropping out of the bushing.

.It will be evident, from the above description. that whenthe launcher is mounted on the rifle barrelv in the manner described above, the head 'I5 of the valve opening stem I3 engages the stem 92 of the valve and moves it rearwardly in its bushing thereby holding the valve head 01T of its seat '88. The tolerance between the end of the barrel and the valve stem will, of course, be taken up by the resilient mounting of the sleeve i4 on the tube 33. Y

Fig. 12 shows a modified form of strap whichY may be used with the launcher. The modified straps H33 are rcharacterized by clamping blocks IM having trunnions H35 at one end pivotally engaged in hook-shaped bearing surfaces ISS formed at the rear ends of the straps. Thus, as the straps are brought together, the forward edges of the blocks engage the rear edges of the front sight mounting and thereby provide means for drawing the sleeve rearwardly relative to the tube and simultaneously opening the gas valve. Y

A modication of the launcher is shown in Fig. 13. As shown, the device comprises a substantially rectangular block II!) having a closed rectangular loop I II at its rear end and a depending rectangular boss H2 at its iront end. A threaded hole I I3 is formed in the forward end of the block and immediately below the threaded hole I I3 and parallel thereto is a second threaded hole II 4 of considerably smaller diameter than the hole H3 formed in the boss H2. A tubular member H5 is threadedly secured in the hole I I3 and constitutes a grenade holder while a relatively long threaded stud H6 is secured in the hole IIL! parallel to the tubular member H5. 1

In use, the cylindrical member I I5 and threaded stud H5 are backed off suicientlyto enable the loop II I to be mounted over the front sight,

the rear edge of the loop engaging'the rear edgev of the front sight' 'Ihe tubular member H5'is then turned up so Vthat its rear endis brought into tight abutting engagement with the muzzle of the rifle barrel. The threaded stud is then turned up suiiiciently so that its end engages the valve. stem and lifts it off its seat. Althoughno means are shown on the cylindrical member H5 for frictionally securing a grenade thereto, it will be understood that a friction ring of the type shown and described above or an equivalent type may be suitably mounted thereon.

What is claimed is:

1. A device for launching projectiles from a rearm comprising a tube; a sleeve slidable thereon; resilient means on said tube constructed and arranged to resist sliding movement of said sleeve on said tube; and means on said sleeve for fastening said tube to said barrel by sliding said sleeve on said tube against the resisting force of said.

resilient means.

2. A device for launching projectiles from a rearm comprising a tube having an external shoulder; a'sleeve slidable on said tube and having an internal shoulder, the shoulders oiY said Vtube and-sleeve being adapted to form an annular recess between said tube and sleeve; a coil spring in said annular recess engageable with the respective shoulders of said tube and sleeve to resist relative sliding movement thereof ;V and straps on said sleeve for fastening said tube to said barrel by sliding said sleeve relative to said tube. Y I 3. yIn a firearm, the combination with a barrel having a front sight mounting; of a projectilelaunching means mounted on said barrel; means for fastening said launching means to said barrel comprising a pair of straps pivoted on opposite sides of said launching means, each strap having a hook-shaped end adapted to engage behind the front sight mounting; and a clip pivotally secured to one strap adapted to lock said straps in engagement with said front sight mounting.

4. The combination with an automatic rearm.

comprising a barrel having a frontV sight mount. ing; of a projectile launching device mounted on said barrel for supporting projectiles to be launched; and means on said launching device engageable with the front sight mounting to secure said launching device on said barrel, said engageable'means comprising a pair of members pivot? ally secured on opposite sides of said launching device and having laterally extending lips arranged to overlie each other in frictionally engaged relationship and in said relationship to cammingly engage the rear edge oi said front sight mounting. Y

5. The combination with an automatic firearm comprising a barrel having a iront sight mounting; of a projectile launching device mounted on said barrel for supporting "projectiles to be launched; means on said-launching device en- -gageable with the front sight mounting to secure said launching devicel on said barrel, lsaid engageable means comprising a pair of members pivotally secured on opposite sides of said launching device, said members having laterally extend-A ing lips arranged to overlie each other in frictionally engaged relationship and in said relationship to cammingly engage the rear edge of said front sight mounting; and a locking device mounted on one only of said members arranged to' clasp 'saidv pivoted members and lock the lips thereof in the aforesaid frictionally engaged relationship.

6. The combination with an automatic firearm comprising a barrel; of a projectile launching device for supporting a projectile to be launched by gas pressure generated in said barrel, comprising a tube mounted on the muzzle of said barrel, a sleeve slidably mounted on said tube, means including said sleeve to resiliently secure said tube to said barrel, and a friction ring on said launching device to releasably retain a. projectile thereon, said friction ring being mounted on said sleeve and slidable on said tube to allow for movement of said sleeve relative to said tube by said resilient means.

PETER B. RUTHERFORD. DONALD R. LUSTER.

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