US2604088A - Air gun - Google Patents

Description

W. S. WELLS July 2.2, 1952 AIR GUN 2 Sl-IEETS--SEIEET l Filed Jan. l2, 1949 fami/Kyi w. s. WELLS 2,604,088

AIR GUN z SHEETS- SHEET 2 INVENTOR. v/f//f'dm 6T w/e/Zf.

/77 @HWK/' v MN www QJ July 22, 1952 Filed Jan. 12, 1949 ASQ 33.53

E .HW H

Patented July 22, A1952 UNITED STATES s accross NT OFFICE AIR GUN l y William S. Wells, Palo Alto, Calif., assignor to Daisy Manufacturing Company,

Plymouth,

Mich., a corporation of Michigan Application January 12, 1949, Serial No. '70,528

This invention relates to airLA guns and more particularly to anv air gun ,construction Which will permit a projectile to be propelled therefrom in a much more eincient and simple manner than has been heretofore known.l

At the present time there are twogeneral'types of air guns, namely, spring type guns and compressed air type guns. In the conventional spring type air gun, a coil spring, having a plunger connected therewith, is compressed, and when the spring is released theplung'er moves so as to simultaneously compress 'a charge Aof air in a chamber and force the air out of the chamber and into the gun barrel, giving velocity to a projectile in the barrel and propelling'the projectile out of the muzzle end thereof. This type of gun is very inefcient,

as the spring must necessarily have a rather long movement, such as two and a half or three inches,

and its Working force, when released, is therefore far from constant. Due to this long movement, a large expenditure of effort is required to compress the spring, and when the spring is released the force exert'edthereby materially decreases as the spring expands. Furthermore, as

. the air chamber is at all times in open communiber, a large amount, of Work must be expended by the user, thus making it a real chore to obtain an air charge of substantial pressure which will in turn impart a high velocity tothe projectile propelled from the barrel. When the trigger of this type of gun is pulled, the air chamber iscommunicated With the barrel and compressed air flows from the chamber. into the barrel, behind the projectile, so` as to propel the latter through the barrel. The air pressure behind the projectile materially decreases as it propels the projectile through the barrel, due to the increase of volume, so that the initial chamber pressure is not maintained. In any air gun one of the main factors regulating the velocity of the projectile is the mean effective air pressure exerted on the projectile during its passage vthrough the barrel. Therefore, asthe pressure of the compressed air flowing through thebarrelrapidly decreases, it

' will be appreciated that the Velocity of the pro- 7 Claims. (C1. 12e-15) jectile will be determined bythe mean pressure vof the compressed air betweenthe initial -hi'gh pressure in the chamber and the relatively low pressure in the `barrel at the time the pellet reaches the muzzle end thereof. The ordinary compressed air gun is therefore extremely inefficient, due primarily lto the fact thatjthe initial compressed air pressure continually'drops during the movement of the projectile through the barrel, thus vWasting a great amount of energy.

The primary object of this invention is to provide an air gun which may be of either the high or low velocity type, or ofthe single shot or repeater type, and in which as higha projectile velccityas possible is obtained with the'expendi'- ture of the least amount oi energy; that isthe `provision of an air gun construction which is as efcient as possible and in which the initial pressure ofa4 compressed air chargeis'siiblstantiallyA maintained for at least a predetermined eik-tent of the movement of the projectile through gthe barrel, after the charge is releasedirom its chamber and flows through the-'gun barrel vthereby eliminating the Waste of energywhich occursin all known air gunsm 1 j It is a still further' objectof thisl'i'nvejntion to provide Aan `air gun of the aforementioned type,

Yin which if the capacity of the compressed'air charge the same or larger` than thev capacity of the barrel, theA initial pressure of lthe compressed air charge will be substantially maintained, even after the charge is released from its chamber and flows into the gun barrel.

It isa further object of this invention to provide an airgun, of the aforementioned type, in which a relatively high projectile' velocity can be `attained with the expenditure of a Aminin n'im amount of work on the 'part of theus'er.

It is a further objectof this invention toprovide, in an air gunof the*afo'rementioned'type, simple, inexpensive and Vnovel means 1for substantially maintaining'the initialpressure of Han air charge after the' charge is-released and moves through the barrel of the gun to discharge the projectile forat least a predetermined extent of the movement of the projectile through the barrel. i' v Itis a still further object of this invention to provide, infa'n air gun of the aforementionedtype, a, novel floating plunger arrangement for'maintaining the aforementioned substantiallyvconstant air charge pressurein-thebarrel, behind the projectile, s ol as to compensate for projectile 4`and ,bar-rel variancea; and any-other ,smally leaks thecompressed airsystemv during operation.

It is a still further object of this invention to provide in an air gun, a chamber in which a charge of air may be compressed, incorporating novel, yieldable means whereby the volume of the chamber will be varied in accordance with the pressure of the air charge, and which chamber may be wholly or partially evacuated into the gun barrel behind a projectile therein, by means of a suitable valve, so that the pressure in the chamber will be substantially maintained in the barrel for at least a predetermined extent of the movement of the projectile through the barrel while the valve is open.

It is a still further object of this invention to Y provide a novel chamber construction and arrangement of the aforementioned type which may be employed in either an air gun of the single shot or repeater type.

It is a still further object of this invention to provide an air gun of the aforementioned type which is relatively inexpensive to manufacture, simple in construction, highly'efficient in operation, easy to use and operate, and durable in construction.

These and other objects of this invention will become apparent from the following detailed description, taken in conjunction with the "accompanying drawings, in which:

Figure 1 is a side elevational View of an air gun of this invention;

Fig. 2 is an enlarged, fragmentary, longitudinal sectional View of the structure illustrated in Fig. 1, illustrating the position of the parts when the gun is ready to be red;

Fig. 3 is a sectional view of the structure illustrated in Fig. 2, taken along the line 3-3 thereof;

Fig. 4 is a fragmentary, sectional view, similar to Fig. 2, illustrating the position of the parts of the gun after it has been fired; l

Fig. 5 is a fragmentary sectional view of the structure illustrated in Fig. 4, taken along the line 5--5 thereof; Y

Fig. 6 is a sectional View of the structure illustrated in Fig. 4, taken along the line 6 6 thereof; and Y Fig. 7 is a fragmentary sectional view, partly in diagrammatical form, of a further embodiment of the invention. 1

`In its broader aspects the air gun of this invention may be of any suitable type and includes a gun barrel through which a projectile may be propelled and a chamber in which a charge of air Vmay be compressed by any suitable means. The

chamber is connected with the gun barrel through suitable Valve means so that upon actuation of the trigger mechanism of the gun the chamber ill without recharging the air chamber. While an air rie is illustrated in the drawings, it will be understood that this invention is equally applicable to other types of weapons and mechanisms such as air pistols or the like.

The air rifle illustrated in Figs. 1-6, includesa stock 1, barrel 9 and trigger guard and housing II, all interconnected vina suitable or conventional manner. A longitudinally extending tubular member or cylinder I5 is disposed below the barrel 9, and the rear portion thereof extends into the stock 1, while the intermediate and forward portions thereof are connected to the barrel, by any( suitable means. A tubular cage member I1 is slidably mounted in cylinder I5 and has one end of link I9, of a scissors type pump mechanism 2|, connected to the forward end thereof. The other end of link I9 is connected to an intermediate portion of a second link 23, which has its forward end pivotally connected to the cylinder I5, adjacent the front end thereof, and which carriesa handle on the rear end thereof. 'I'he handle 25,y as canbe seen in Fig. 1, is normally Vdisposed in an abutting relationship` with the under side of the cylinder I5, but is movable downwardly and forwardly, as shown in dot dash lines, so as to move the cage member I1 forwardly in the cylinder I 5.

A plunger or piston 21 is slidably disposed in the cylinder I5 rearwardly of the cage member i1. The plunger 21 includes a seal 29, a nut 3i having a recess 32 in the front face thereof, and a rigid head 33. One end of al rod like member 35 is threaded into the plunger 21 and secured thereto in any suitable manner so as to properly retain-the seal 29 betweenthe head 33 and the nut 3I. The opposite end of the rod 35 slidably extends through an aperture 31 in an abutment member 39 in the cage I1, and is adjustably conmay be wholly or partially evacuated into the barrel behind the projectile. The chamber incorporates novel, yieldable means whereby the volume of the chamber. will be varied in accordance with the pressure of the air charge therein and which means are so constructed and arranged as to substantially maintain the chamber air pressure in the barrel, when the valve is openffor at least a predetermined extent of the movement of the projectile through the barrel. In the event that the capacity of the air charge evacuated from the chamber into the barrel is the same as or greater than the capacity of the barrel, then the initial chamber compressedair pressure will be substantially maintained in theV barrel until the projectile is discharged therefrom. lIt will thus be appreciated that the air gun of this invention may be of either the single shot or repeater type, that is, the type in which a plurality of projectiles may be rcd from the gun nected thereto by means of a nut 4I. A coil spring 43 surrounds the rod 35 and extends between thecage abutment member 39 and the plunger head 33. The spring 43 is normally set or preloaded, for reasons-which will hereinafter appear, by tightening the nut v4I against the abutment member 39 so as to compress the spring the desired amount. It will thus be appreciated that a yieldable lost motion connection is provided between the plunger 21 and the cage I1; that is when theV cage I1 is moved forwardly in the cylinder I5 by the scissors pump mechanism 2|,

the plunger 21 will be carried therewith, but the plunger 21 is movable relative to the cage I1 either against or under the-action of the spring 43, as will hereinafter appear.

A valve body or plug 45 is disposed in the cylinder I5, rearwardly of the plunger 21. The

plug or valve body 45 is rigidly connected to the innerr wall of the cylinder I5 by any suitable means, such as soldering, soV as to provide an air tight connection. The valve body 45 has a longitudinally extending passageway 41 therein which extends rearwardly from the front face thereof and which communicates with a vertically extending passageway 49, adjacent the rear of the valve body. A valveV element 5I is slidably mounted in the valve body 45 and has its stein portion 53, which is of a smaller diameter than the passageway 41, extending rearwardly through the passageway 41 and slidably through an opening or bore 55, rearwardly of the vertical passageway 49. The valve element 5I has a head 51 formed on the forward end thereof, which norr2,604,088 Y y yexterior portion of the valve stem 53. rearwardly beyondl the valve body 45, andone end of the spring abuts the rearface ofthe valvegbody 45 .threaded on the rear end of the valve stem.A The spring 6| normally holds A`the valve head 5.1 in sealing engagement'with the valve body .seal 59 so as to close offthe valve against the flow of air therethrough. A tapered tube v|55 is tightly fitted into the upper end of the valve body vertical passageway 49 and has its upper end extending through an aperture E9' in the cylinder |5 and the barrel 9. Y The tube 65 is soldered into the aperture 69, soas to prevent any leakage of air therearound. The valve body longitudinal passageway 41 is therefore in .unrestricted communication with the rear portion of the barrel at all times.

A bolt is slidably` mounted in the rear porf tion of the-barrel '9 and has an outwardly 'projecting, rotatable boltA handle 11 connected thereto at'16. The boltfhandle 11 projects outwardly through an L-shaped'slot 19 in the barrel 9, and through a short Vertical slot 18, in a sleeve-like member 80, which is slidably mounted on the rear portion of the barrel and connected to the rear portion of the bolt by pin 82. A pin |i| is oonnected to an intermediate portion of thebolt and extends downwardly through the sleeve B0 and a slot 83 in the barrel 9 and the cylinder I5 for cooking the gun hammer 84 in a manner which will be hereinafter described. The barrel 9 is provided, rearwardly of the valve body tube G5, with an elongated slot or notch 85, into which s. pellet or shot member 01 may be dropped after the bolt 15 and sleeve 89 have been pulled rearwardly, as shown in dotted lines in Fig. 2. vAfter ,the pellet 81 lhas been placed in the barrel slot y in a manner which will be described.

A plug member 9| is secured in the extreme rear end of the cylinder I5 and is provided vwith a recess 93 in the front face thereof, in which one end of a coil spring 95 is received.- The plug member 9| is also provided with an aperture or bore 91, rearwardly of the recess 93, in which the rear end of an elongated cylindrical pin member 99 is secured. The yhammer 94 is slidably supported on the pin 99, and the rear portion of the hammer slidably ts the bore of the cylinder I5, while the front portion thereofis reduced in diameter so as to provide an annular hammer shoulder |03. The back face of the hammer 84 is recessed at |95 to receive the forward end of the spring 95. The pin 99 vsupports and guides the hammer 84 for forward movement into engagement with the valve stem 53 in the valve body 45.

W'hen the bolt 15 is pulled rearwardly, the bolt pin 8| engages the shoulder |03 of the hammer 34, so as to slide the hammer rearwardly to its cocked position, and compress spring 95. The hammer is held in its cocked position by means of a sear |01 which is supported on a pin |09 in the trigger guard and housing II. The sear |91 is of the hair pin type and one leg thereof extends through a slot |08, in the underside of the cylinder I5 so as to engage the hammer shoulder |03, while the other leg thereof engages a nose portion I of a trigger I I3, which is mounted'in'th'etrigger guard and housingj I jby means of pivot pin I l5. vThe trigger ||3 Vis normally held in a cocked position for Vactuation by suitable means suoh asa spring I|1. When the trigger ispulled, it rotates the sear `Iii'i so as to release the hammer for forward movement under the action of the spring 95.

In order to operate the gun, thescissors handle 25 is pulled downwardly by ythe user so that the cage |1r and plunger 21 are moved 'forwardly in the cylinder I5 until the plungerZT-passes beyond an air inlet opening I2I'in the'underside of the cylinder, as shown indot and dash lines in Fig. 2. The soissorshandle 25 is then pulled upwardly and will move the cage I1 and plunger 21 to the rear so as to' compress the air in the cylinder |5 between the plunger and the valve body 45. As the plunger `21moves `rearwardly the pressure of the air in thecylinder chamber between the plunger and valve body will beincreased.

Due to the fact that the Vspring 43 between the cage and plunger has been preloadedV or set a forwardly in the cylinder', relative'to the cage Il,

and will compress the spring 43. It will thus he appreciated that after thescissors handle 29 is back in its normal position the sprir'igr 43 will have been compressed until the forces exerted-cn each side of the plungerv by the compressed air and the spring are equal. f

Preferably, for single shot guns, such as the one illustrated, the capacity or'volume of the cylinder chamber, in `which the air is compressed,

is relatively small, and the amount of compresv y.

sion of the spring 43, caused by the compressed air force, is relatively small, 'due to the fact that the spring was initially preloaded.vv That is, the spring is constructed so as'to be capable of exerting a force equal' tothat exerted by the compressed air, irrespective of the size of ther chamber, by being operatively compressed only a relatively small amount, and Without bottoming. It

will of course, be appreciated that the volume or the cylinder chamber and the value of the spring may be varied in order to obtain various firing conditions, as well as for different types and sizes of guns.

After the scissors pump` mechanism has been actuated so as to charge the gun, the bolt 15 and sleeve are pulled rearwardly, so as to cock the hammer 84, as previously described, and a pellet is placed in the barrel slot or notch S5. When the bolt and sleeve are moved forwardly,.the bolt positions the pellet just' ahead of the valve body 7 Y 9 just rearwardly of the pellet -81 so as' to move the pellet 81 forwardly through' the'bo're of the vbarreland out of the muzzle end thereof. As soon as the valve element has been opened the volume ofthe compressed air will begin to increase, which would normally tend to decrease the pressure of the air. l However, the initial pressure of the air is substantially maintained with the construction of this invention due to vtheV fact that as soon as the volume increases,: and the pressure tends to decrease, the spring 43 starts to expand and use its stored up energy to move Ythe plunger 21 rearwardly so as to reduce the volume in the cylinder chamber, between the valve body 45 and plunger 21, and maintain a substantially constant air pressure in the cylinder chamber and barrel 9, behind the pellet 81. Due to the precompression of the spring and the relatively small expansive movement of the spring, there will be only a very small or infinitesimal drop in the air pressure, due to the loss of energy in the spring as it expands. A sub--` stantially constant tension or forceis thereforeY Therefore, if the capacity of the compressed air chamber, between the plunger 21 and valve 45, is the same as or larger than the capacity ofthe barrel 9, the pellet will be propelled through the barrel and out of the muzzle end thereof by a pressure of air which is substantially the same as the initial pressure in the chamber. Therefore, practically all of the compressed air is used, without any drop in the initial pressure, and with only a very slight loss of energy. The floating plunger arrangement also permits the substantial maintenance of the initial cylinder chamber pressure, even though there are small leaks in the compressed air system, during the .firing operation. That is, the spring 43 will move the plunger rearwardly so as to compensate for any Y drop in air pressure caused by ,barrely orrpellet variances, or any otherA small leak in the gun. After the pellet has been discharged from the muzzle end of the barrel, the plunger 21 and operating parts of the mechanism will bedisposed in the position illustrated in Fig. 4. If the capacity of the compressed air chamber: is less than the capacity of the barrel, the initial compressed air pressure will be maintained in the barrel for only a predetermined extent of the movement of the projectile therethrough. Even under this latter circumstance the eiciency of the gun of this invention is extremely high, as can be readily appreciated and is Ymuch higher than any now known in the art.

While the gun illustrated in the drawings is of the single shot type, it will be appreciated that it may be modified for use as a repeater type without deviating from the invention hereof.

The work applied by a user to compress the air Y in the cylinder, so as to attain a desired projectile velocity, is relatively small as compared to conventional compressed air guns, thus vmaking this gun one that can be easily operatedanld one in which several strokes of the scissors pump are not necessary in order to build up a satisfactory air charge to properly propel the pellet from the barrel. This results from the fact that the main factor regulating the velocity of the pellet is the mean eifective air pressure exerted on it during its passage through the barrel, and therefore this gun can attain a pellet velocity equal to that of a conventional compressed air gun without the compression'of air in the cylinder chamber to as high a pressure as in a compressed fective mean pressure edual to the initial pres-` sur'e vof the air charge in thegun of this invention,in order to obtainv substantially the same pellet-velocity.

It will also be understood that the velocity and pressure characteristics of this gun could be altered by varying such factors as the K factor of the spring, the length of barrel bore, the capacity of the chamber in which the air is compressed, the weight of the shot or pellet and the pressure to which the air is to be charged. By properly co-ordinating all of these elements, various muzzle velocities can be attained, but in all cases the initial-pressure of the vair charge will be substantially maintained, as previously pointed'out. f "Y, 'In the embodiment illustrated in Fig. 7, an air compressing piston or'plun'ger |25 is disposed in the forward portion of theI ycylinderV |5 and has its rod'portion |21 connected toa pump mechanismvof any suitable type suchfasthe scissors mechanism previously'described. rAcheck valve |29 of any suitable type is disposed inthe cylinder l5 rearwardly of the plunger |25 and forwardly of conduit means |3|, which connects the rear portion of the cylinder I5' with the barrel 9', behind a projectile 81 disposed therein. A plunger 21', similar to the plunger 21 previously described, is slidably disposed in the cylinder 'I5' rearwardly of the check valve |29. Spring 43 surrounds the rod 35' of the plunger 21' and the rear end of the spring 43 engages any suitable cylinder abutment such as thewall portion |33. The plunger rod 35 extends through the abutment |33 so that the plunger'21 can move toward and away from the check valve |291 Suitable firing valve means |35 is provided for normally closing the conduit |3|`against the flow of air from the cylinder I5' to the barrel 9. means |35 may be of any suitable type and may be actuated yin any desired manner, when the trigger of the gun is pulled, such asis shown in the previous embodiment or as shown in the applicants co-pending application for Mechanism for MaintainingA Substantially Uniform Muzzle Velocity for Pneumatic Guns, Serial No. 762,391, led July 21, 1947, and now abandoned, so that the chamber between the check valve |29 and the plunger 21vfmay be either partially or completely evacuated each time the trigger is pulled, in accordance with whetherthe gun is of the single shot orrepeater type.

In operation the chamber between the check valve |29 and plunger 21 is charged by operating the pump mechanism so as to cause the air compressing plunger |25 Vto compress air in the chamber between the check valve |29 and the plunger |25. When the'air-is compressed in this latter chamber to a suitable pressure the check valve |29 is opened to permit the air charge to flow into the chamber between the check valve 29 and the plunger 21'- By operating the pump mechanism and air compressing plunger |25 one or more strokes, an air charge of a relatively large pressure can be built up in the cylinder chamber between the check valve and the plunger 21. When the force exerted by the air charge in this chamber exceeds the force exerted 'against the The valve plunger*2'l'jb'y` the spring' 43',v the ,plunger 21 will move rearwardly inthe cylinder in the same manner as previouslyjdescri'bed until a balanced conditionis obtained between the spring and air charge. When the trigger is pulled so as to open the valve 135, to either evacuate a portion of the air charge in the chamber or all of the air charge, in accordance with the valve and ring arrangement used, the compressed airwill flow from the cylinder chamber through the conduit ISI, and intoy the barrel 'Q behind the projectile 81', to propel the projectile fromthe barrel as Vpreviously described.l As soon `asjthe ,vaive |35 is opened so' that the volume ofthe chamberisincreased andthepressure'of the air charge tends to decrease the plunger 2l will move forwardly, under the action of the spring 113l to'reduce the volume of the chamber ras previouslyA described in the embodiment shown in Figs. l-5. In this way, as long rasthe valve |35 is open, the plunger'i21 will be moved by the spring 43 to maintain the initial cylinder chamber air pressure in the barrel behindthe projectile for at least a predetermined extent of the movementof the projectile through the barrel.v As has been previously pointed out, this extent will depend upon the relative capacities of the barrel rand the charge of air which is evacuated from the chamber and iiows into the barrel. y It the capacity of the air charge is less than the barrel, the initial air pressure will not be maintained throughout the entire extent of the movement of the projectile in the barrel, but if the capacity of the air charge is greater than the barrel capacity, then the initial cylinder com pressed air pressure will be substantially maine tained until the projectile is discharged from the barrel;

It will thus be appreciated that with the gun of this embodiment, the efliciency and substantial maintenance of the'cylinder compressed air pres-y sure will'be maintained in the saine manner as previously described, but in this embodiment a separate air compressing plunger orv piston is employed for compressing the air in the chamber,

vwhich may be more'advantageou's in repeater type guns, although it will be readily appreciated that either embodiment may be used as either a single Vshot or a repeater vtype* gun.

What is claimed is: y

1.,An air gun including a barrel adapted to re-' ceivc a projectile, a chamber for the receptionof a charge of compressed air, normally closed valve means connected with said chamber andfbarrel and adapted to be actuated so as to communicate said chamber with a portion of" said barrel be'- hind a projectile disposed therein,A an element slidably connected withv said chamber for movement toward and away from said valve means, movable plunger means disposed in said chamber, means providing a lost motion connection between said slidable element and said plunger means, means for moving said slidable element toward and away from said valve means sovv that said plunger means will move with-said element away from said valve'fmeans,` andH so that said plunger means can move relative-to said element when said element is moved toward said valve means, resilient means acting against the opposite side of said plunger meanslfrom the charge of 'compressedl air and adapted to' be compressed byffmovement of said plunger' means caused by force exerted on said plunger vmeans by the compressed air so as to equalize Athe force applied against said plunger means bythe compressed air, and means for actuating'sa'id valve means so" as to permtthscompr'essed air saidV chamber to iow` into said barrel portion, whereby said plunger and' resilient "means will substantially maintain the initial chamber compressed air pressure' inV said .barrel for at least a vpredetermined extent of the'rriovement of the 'projectile tlirugl th .'ba'lt i v 2. An air gun including a barrel adapted te rceive a projectile. a cylinder, normally closed valve means in said cylinder adapted to be actuated' so as to communicate a portion of said cylinder ron one side of said Valve means with a pcrtion'of seid berm behind a projectile disposed therein, means for compressing air in said cylinder on said one side of said valve means, including mcvabiefiiiuriger means, element siidaiiiy connected with said' cylinder vfor movement towar'd `and away ironisaid valve means. means providing 'a lost motion connection betweensaid siidabie eiement 'and `said mutiger means, means for moving said `slic'ialfile eleinnt toward and away from Asaid valve means so that said plunger means will move With said element away from said valve means and so that said plunger means can move relative to said element when said ,element is moved tCi'vvady Said Valve means, resilient means acting against the opposite side of said plungerY means from said Compressed air, said fslient means being preloaded or set so as to exert apredetermine'd force` against said plunger means, said resilient means being' adapted tobe compressed by movement of said plunger' caused by force exerted. onsaid plunger bys'aid compressed air" so as to equalize the force appliedagainst said plunger by the yc(impressed air, and means iii-f cluding a. trigger element actuating saidilif means so as to permit the compressedaii between said plunger and valve means to iiow int said barrel portion, whereby said plunger and resilient means Will silbstarltiallyihaintai th initial cylinder cofiipresdv air. pressure in Said barrel for atleastv a predetermined extent of the movement o-f the projectile through the barrel.

3. lAn air gun including a barrel adapted to r'e' ceive a projectile, a cylinder, normally closed valve means in said cylinder adapted to be' ac`- tuatedv so as to permit a flow of air from cile side of` said. valve means toA said barrel behind a pro jectile 'thereiri, cage means slidably disposed in said cylinder on the one side of saidv valve means'. a plunger slidably mounted in said cylinder be# tween said cage means and. valve means. means providing a lostrmoti'onconnection between said cagev means and plunger, a vspring disposed between` said plunger and cageV means, means' forv moving said cagemeans towardand away' from said valve meansso das to compress air between said plungerv andi valve means, said springv b arrangedv and. constructed se as to bcOmpre sible by the movement ofr said plunger'after the' air compressed between said valve means and plungerl has reached' a''predeterminedv pressure) whereby to A equaliae the f'orces' acting onea'ch side of.A said plunger, and means. foriV actuating Said Val-Ve lrealls' Sofs tol-iili't tli Ci'ipiSSe'd air betWee-said'plngei and` yvalve means to' flow' into said barrel' and" 'preset the projectile' there: from,4 whereby as the" compress'ed'` air" saidf Cylinder moves into Saidbalrfel', s'lid'v'plllnger'will be moved toward lsaid'valve means by said come pressed spring, so as to maintain the' air' pres`v sure 'in said barrellsubstantially equal" to" `the initial' compressed'air pressure in' said' cylinder fori at least: a predetermined Vextent-offtiiej ment of the projectile througli the barrel'.

aco/ross 11 4. An air gunni1-icludingl a barreLa cylinder adjacent l"saidv Ybarrel, .normally closed Vvalve means "irrsa'id cylinder adaptedv to be actuated so as to'j'acommunicate' aiportionof said cylinder alieadioif'lsaid valve means with a rear portion of saidjloar'rel,Vv cage Ymeans `slidably disposed in said cylinder ahead of said valve means and movable toward Vand away from said valve means, a plunger "slidably mounted in said cylinder between said valve means and' said cage means, means including a resilient element between said plunger` andY Icage means providing a yieldable lost Vmotion `connection between said plunger and said cagemeans so that said plunger will move with said cage means when the latter is movedpgaway from said valve means "and so that said plunger can move relative 'to said cage means against or under the action of said resilient element, means ,connected with said cage means for moving the same in saidV cylinder, whereby when`v saidplnger ismoved toward said valve means the air therebetween will be compressed and when the pressure ofthe compressed air exceeds the force normally exertedV by the resilient element onv the plunger; theplunger will move toward the cage means and will compress said resilient element until an equal force is exerted on each side of the plunger by the'compressed resilient element and the compressed air, means 'including a trigger adapted to be actuated after the air is compressed between the plunger and valve means so as to actuate said valve means and permit the compressed' air to flow into said barrel portion, and means for cooking said gun and positioning a projectile in said barrel for propulsion by said compressed air, whereby when a projectile is in said barrel the flow of compressed airinto the latter will cause the projectile to move through said barrel toward the muzzle end thereof and whereby as the pressure of the compressed air in the cylinder between the valve means and plunger tends to decrease due to the llow of air into the barrel, the vresilient element will move the plunger toward said valve means so as to substantially maintain the initial compressed air pressure in the cylinder and barrel for at least a predetermined extent of the movement of theprojectile through the barrel.

' 5. Ina iiuid operated device, a cylinder, normally closed valve means in said cylinder adapted to be actuatedso as to permit fluid to iiow therethrough, cage means slidably disposed in said cylinder on one side of said valve means, a plunger slidably mounted insaid cylinder between said cage means and valve means, means providing a lost mostion connection between said cage means and plunger s that when said cage means is moved away from said valve means said plunger will be carried thereby and so that said plunger can move relative to said cage means, a spring disposed between saidl plunger and cage means, and means for moving said cage means and plunger toward and away from said valve means so as to compress fluid between said plunger and valve means, said spring being arranged and constructed so as to be compressiblc by the movement of said plunger after the air compressed between said valve means and plunger has reached a predetermined pressure, whereby to equalize the forces acting on each side of said plunger.

6. In a fluid operated device a cylinder, normally closed valve means in said cylinder adapted to be actuated so as to permit a flow of fluid therethrough, cage means slidably disposed in` 12 saidcylinder on one side of said valve means, a plunger slidably mountedlin said cylinder between said cage means rand valve'means, means providing a Vlost motion connection between said cage means and plunger, va springdis'posed between said plunger and cage means, means for compressing fluid between said plunger and valve means, said spring being preloaded or set between said plunger and cage means by said lost motion connection means soV as to be compressible by the movement of said plunger caused by the force exerted thereon by said compressed air only after said compressed air force has exceeded a predetermined value, whereby to equalize the forces acting on each side of said plunger. 7. An air gun including a barrel adapted to receive av projectile, a cylinder, normallyy closed valve means in said cylinder adapted to be actuated so as to permit a i'low of iluid from one side of said valve means to'said barrel behind a projectile therein, cage means slidably disposed in said cylinder on the one side of said -valve means, a plunger slidably mounted in said cylinder between said cage means and valve means, rod means having one end connected to said plunger and the opposite end connected with said cage means so as to provide a lost motion connection between said cage means and plunger, whereby when said cage means is moved away from said valve means said plunger will be carried thereby and whereby said plunger can move relative to said cage means, a coil spring disposed between said plunger and cage means, means for moving said cage means toward and away from said valve means so as to compress air between said plunger and valve means, adjustable means connecting said rod with said cage means so as to preload or set said spring. whereby said springY is compressible by movement of said plunger caused byforce exerted thereon by air compressed between said valve means and plunger only Vafter said force has reached a predetermined value, so as-to equalize the forces acting on each side of said plunger, and means including a trigger element and hammer means for actuating said valve means so as to permit the compressed air between said plunger and valve means to flow into said barrel WILLAM s. WELLS.

REFERENCES CITED' The following references are of record in the le of this patent: f VUNITED STATES PATENT Number Name Date 558,841 Raymond Apr. 21, 18916 1,214,398 Welch Jan. 30, 1917 1,441,975 Edelin Jan. 9. 1923 1,478,597 Bebler Dec. 25, 1923 1,512,993 McLean Oct. 28, 1924 1,539,769 Poillon May 26, 1'925 2,283,300 Vincent May 19, 1942 2,450,029 .Wel1s, v Sept. 28, 1948

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