US2818056A - Compressed gas-operated propelling mechanism - Google Patents

Description

Dec. 31, 1957 R. s. MARTIN coMPREssED GAS-OPERATE'D PROPELLING MECHANISM Filed Feb. 28, 1955 2 Sheets-Sheet 1 Dec. 31, 1957 R. s. MARTIN 2,818,056

COMPRESSED GAS-OPERATED PROPELLING MECHANISM Filed Feb. 28, 1955 El o gl 10 104 2a 24 5 11 a2 114 2 Sheets-Sheet 2 4 56 f i 3 E? f 2404/?9/415/ 2f )f1/6) 06 j `.IN1/EN TOR. af/er 6.1444671 United States Patent COMPRESSED GAS-PERATED PROPELLING NECHANISM Robert S. Martin, Los Angeles, Calif.

Application February 28, 1955, Serial No. 490,778

4 Claims. (Cl. 124-11) This invention relates generally to a compressed gas operated propelling mechanism and will be particularly described and illustrated herein as embodied in a weapon for firing projectiles such as -a pistol, although it is to be understood that the invention is not limited to such uses. For example it may be applicable to machines for periodically propelling any of a wide variety of objects in a predetermined direction, as will be seen as the description progresses.

This invention is an improvement over that shown in my United States Patent No. 2,688,321.

in the presently preferred embodiment herein shown and described, a pistol includes a frame having a grip portion provided with a cavity for housing a container of pressure gas such as, for example, a cartridge of caroon dioxide. The frame also includes a bore and means for supporting a tubular barrel slidable relative to the frame. Spaced relatively movable bushing members or sleeves hermetically seal with the bore and barrel thereby forming a variable volume compression chamber. Pressure gas from the container is continuously fed into the chamber, and gas from the chamber is periodically admitted into the barrel for firing during the cycle of operation through one or more ports formed in the barrel wall. A feeding magazine containing a plurality of projectiles or pellets projects into the barrel from the rear and is adapted to release one such pellet at a predetermined point in the cycle, by camming interengagement between the inner end of the magazine and cooperative means carried by the barrel.

Suitable trigger mechanism is provided for retaining the barrel in inoperative or rearward position and for releasing the barrel for forward movement and firing when the trigger mechanism is manually actuated. The trigger mechanism is conventional and may assume any of various forms including, if desired, suitable safety lock means well known in the art by which actuation of the trigger is prevented until the safety lock is moved to tiring position. Since the present invention is not directed to the details of a trigger mechanism, such mechanism is herein shown and described in stylized form only in order not to detract by complexity from an understanding of the present invention proper. The weapon is adapted for either semiautomatic or full automatic operation.

A principal object of the invention is therefore to disclose a novel weapon for operation by compressed gas.

Another object is to disclose a gas operated weapon constituting an improvement in certain respects over my earlier invention shown in United States Patent No. 2,688,321.

A further object is to disclose a gas operated Weapon including means forming a variable volume compression chamber in periodic communication with the interior of av reciprocable barrel.

Another object is to provide, in a gas operated weapon magazine means for holding a plurality of projectiles and for releasing'one such projectile for ring at the proper point in the cycle of operation.

Patented Dec. 31, 1957 Still another object is to provide in a weapon having the above characteristics, resilient cumulator means by which to maintain propelling gas pressure at a relatively high value throughout the travel of a projectile through the barrel,

These and other and allied objects and purposes will be understood from a study of the following description of a preferred embodiment of the invention taken in connection with the accompanying drawings in which:

Fig. l is a longitudinal sectional view of a gas operated pistol embodying the present invention.

Fig. 2 is a fragmentary sectional view, on an enlarged scale, showing the rear portion of the barrel and the front portion of the feeding magazine therein, together with associated parts, the weapon being cocked` Fig. 3 is a sectional view similar to Fig. 2 but showing the parts after the trigger has been pulled, the barrel has moved forwardly and a projectile has been released from the feeding magazine and has moved partially through the barrel.

Fig. 4 is a sectional view similar to Figs. 2 and 3 but showing the parts at a later point in the cycle of operation with the barrel, under the force of the recoil spring, commencing its rearward movement back toward cocked position.

Fig. 5 is a fragmentary sectional View on a larger scale than that of Figs. 2, 3 and 4 and showing the projectile entering the forward section of the barrel, the parts being in their positions a moment earlier than that shown in Fig. 3. f

Referring now in detail to the drawing and first to Figs. l and 2 thereof, the weapon there shown includes a housing frame indicated generally at lll provided with a forwardly projecting barrel support sleeve 12 securely lixed to the front end portion 14 of the frame ll) as by transverse drift pin i3. Conventional sighting means are provided including rear sight l5 and front sight 16. Formed within frame l@ is a longitudinal bore 18 and barrel support means are provided within the bore 18. The barrel support means are here shown as including a rear bushing indicated generally at Ztl and a front bushing indicated generally at 22. The bushings are provided with coaxial longitudinal bores therethrough indicated at 24 and 26 respectively. The rear bushing 2t) includes means hermetically sealing with the internal wall of the bore 18 such as an O-ring 28, and the' rear bushing remains stationary relative to the frame 10 when the parts are assembled, being in abutting relation with the shoulder 30 of the frame. Except for convenience in assembly of the parts, rear bushing 2i) could be made integral with frame 10. Rearwardly of the shoulder 3@ the bushing 2li includes a portion of reduced diameter 3l.

The front bushing 22 includes means hermetically ysealing with the wall of the bore 18 such as -O-riug 32, and

is arranged Ito be longitudinally movable within the bore 18 of the frame relative to the rear bushing 2l?. The front bushing also includes a forwardly extending, preferably integral sleeve 34 of reduced diameter. Resilient means are provided for urging the front bushing 22 rearwardly relative to the frame 10, and such means are here shown as including a helical spring 36 bearing at its front end against Athe rear annular end 37 of the barrel support sleeve l2 and bearing at its rear end against the enlarged portion of the bushing 22.

The pistol includes a barrel indicated generally at 40, the barrel being longitudinally movable or reciprocable relative to the frame 1t) and its forward extension or barrel support sleeve 12. The forward portion of the barrel is slidably carried by the barrel` support sleeve 12 and the barrel is supported rearwardly by the coaxial bores 24 and 26 within the bushings 20 and 22 previously referred to. The outer cylindrical surface of the barrel 3 is provided with means hermetically sealing with the bore 24 of the rear bushing 20, these means being here shown as an O-ring 42. Rearwardly of this O-ring is a second hermetic seal between the rear bushing `and barrel indicated at 44 and also consisting `of an O-ring or equivalent sealing device. The front .bushing 22 is provided with means hcrnietically sealing with the barrel in the 4form of O-ring 46. Forwardly of the front bushing 22 the barrel includes an annular ring or collar 48 received in a recessed groove in the outer surface of the barrel and extending outwardly beyond the groove, and the front bushing 22 is in abutting contact with the collar 48 from the rear by means of sleeve 34 when the parts are in the positions seen in Figs. l and 2 of the drawings.

Means are provided for resiliently urging the barrel 40 rearwardly relative to the frame 10, such means being here shown as including a recoil spring 50 helically disposed about the barrel 40. The recoil spring S0, at its front end, bears against an annular shoulder 52 formed in the barrel support sleeve 12 and at its rear end bears against the outwardly turned lip S4 of a spacing collar 56. This collar 56 is slidably mounted in the barrel 40 and at its rear end is abuttable against the ring 48 extending annularly from the barrel 40.

At the rear end of the barrel 40 there is a barrel extension fixed to the barrel and of larger diameter. The barrel extension is indicated generally at 60 and includes the enlarged cylindrical member 62 and a forwardly projecting preferably integral tube or sleeve 64 fitting within the rear section 65 of barrel 40. It will be noted that the rear section 65 of the barrel is of considerably larger inside diameter than the inside diameter of the forward part of barrel 40 including the firing tube 66. The barrel extension 60 is fixed to the rear section of the barrel 40 and could be formed integrally therewith if desired.`

A suitable trigger assembly is included in the present weapon and may assume any of many forms well known in the art. Illustratively, the trigger assembly may include the trigger proper mounted for pivotal rotation on the frame about the pin 72. The trigger is provided with a rearwardly projecting arm 74 which, at its rear end, abuts upwardly against an arm 76 of a linkage member indicated generally at 78 pivotally mounted on the frame for rotation about the axis 80. The linkage member 78 includes a rearwardly extending arm 82 terminating in an upwardly extending sear member 84 which, when the weapon is cocked, abuts the annular front surface of the enlarged portion 62 of the barrel extension 60. The trigger linkage mechanism herein typified includes resilient spring members 86 and 88 urging the parts ofthe trigger linkage into the positions seen in Figs. 1 and 2.

Means are provided for supplying pressure gas to propel a projectile through the barrel 40 during tiring. Such means are here shown as including a container `ot compressed gas indicated generally at 90 and housed within a suitable recess formed in the grip portion 92 of the pistol. The pressure gas container 90 may be replaced when desired by removal of a suitable closure member indicated generally at 94 which normally retains the gas container 90 in the position shown. A passageway indicated generally at 96 extends between the gas container 90 and the bore 18 formed in the frame 10, and the passageway 96 terminates upwardly at a port or orifice 98 located just forwardly of the front annular face 99 of the rear bushing 20. The passageway 96, at its lower end, is provided with a suitable piercing member 100 adapted to perforate the upper end wall of the pressure gas container 90 when such container is inserted into the housing recess formed in the grip 92 and the retainer plug means 94 is tightened thereon.

Means .are .provided for supplying projectiles or pellets intothe rear portion of the barrel of the present weapon. In .the present illustrative embodiment of the invention such loading or feeding means include an elongated tube indicated generally at which is threadedly connected at 112 with the rear portion of the frame, being assembled therein from the front of the frame. The tube 110 includes an enlarged llange 114 abutting a shoulder formed within the frame of the weapon and forwardly of the ange 114 the tubular member 10 is of a smaller diameter as indicated at 116 and lits within sleeve 64 of barrel extension 60. The front end portion of the tube 116 is provided with a plurality of vforwardly projecting resilient arms 11S (see Fig. 5) separated by longitudinal slits 120 therebetween. The arms 118 are resilient and tend `to move outwardly from the center of the tube 116. Toward their front end the arms 118 incline outwardly to offset portions 122 and at the extreme front end the arms incline inwardly and terminate in directed fingers 124.

A number of projectiles 126 may be inserted and carried within the tubular member 110 in tandem, there being six such `projectiles shown in Fig. l. Resilient means :are .provided for urging the projectiles 126 forwardly .within the `tube and into abutment against the inturned fingers 124 of the tube. These resilient means include a relatively weak spring member 130 extending longitudinally `within a sleeve 132, and the sleeve 132 terminates at its rear end in a loading cap 134. The sleeve `and cap .are threadedly connected at 136 to the rear end ot the loading tube 110. The forward end of the spring `130 abuts a follower tip 14() which in turn is in abutting .contact with the rearmost one ofthe projectiles 126 .and .continuously urges the train of projectiles forwardly when the parts are assembled. The cap 134 may be desirably knurled at its outer surface to facilitate manual removal of it and its integral sleeve 132 containing the spring 130, and when so removed additional pellets or projectiles may be introduced through the then open rear .end of the loading tube 110. Thus the parts just described constitute a spring loaded magazine for continuously supplying projectiles to the forward end of the tube 116, at which point the projectiles are restrained from further forward movement by the inturned lingers 124 until the appropriate moment in the cycle of operation of the weapon as will be described in detail here. inafter.

The barrel 40 is of virtually uniform outside diameter throughout Aits length; the forward section of the barrel has an inner diameter 66 throughout the tiring tube proper, while the rear section of the barrel has an inner diameter 144 :considerably greater than that of the forward section. As best appears in Fig. 5, the two sections are connected by an internal rearwardly directed inclined annular shoulder 146 smoothly joining the two inner bores of different diameter. Adjacent the in clined annular shoulder 146 the rear section of the barrel 40 Aincludes on or more ports 148 through the wall `ot the barrel. As will be later understood, these ports 148 periodically admit `pressure gas from outside the barrel into the ,interior of the rear section thereof, the pressure gas constituting the `propellant for the projectile 126.

The .cycle of operation of the present weapon will be best understood by considering Figs. 2, 3 and 4 showing the parts in their respective positions at successive stages in `the c ycle. It may be noted at this point that the fragmentar-y view in Fig. 5 shows the parts a moment earlier than that shown in Fig. 3. With reference first to Fig. 2, pressure gas is admitted into the chamber 102 through the passageway 96 and the inlet port 98. The pressure within chamber 1 02 is exerted forwardly against the annular face 104 -of the front bushing member 22 and its force is .thereby applied to the barrel by reason of the abutting contact between the front `annular shoulder of .the .sleeve 2.6.01 bushing 22 and the ring collar 48 carried by the barrel. This force resulting from the gas pressure fin chamber 102 is more than sutiicient to overcome the rearward force upon the bushing 22 caused by cumulator spring 36 and also the rearward force exerted upon the ring collar 48 through the spacer member 56 by the recoil spring 50. Thus the resultant force on the barrel is forwardly, and the barrel is restrained from actual forward movement by abutment of the sear 84 against the forward annular shoulder of the barrel extension 60. It will be seen that pressure gas existing within the chamber 102 is prevented from escaping therefrom by reason of the hermetic sealing members or O- rings 32, 46, 28 and 42.

At this time forward movement of the projectiles 126 under the influence of the weak follower spring 130 is prevented because the fingers 124 of resilient arms 118 are cammed into their inner positions blocking the front'projectile 126 by reason of the caming action of the internal annular shoulder 146 against the offset portions 122 of the arms.

The parts move into the position seen in Fig. and thence into the position seen in Fig. 3 when the trigger is actuated and the sear 84 is drawn downwardly by such actuation. With reference iirst to Fig. 5, forward movement of the barrel 40 relative to the rear bushing 20 permits the oifset portions 122 of the arms 118 to spring outwardly because of ktheir sliding or camming engagement with the annular shoulder 146 on the interior of the barrel. arms 118 and their lingers 124 releases the front projectile 126 and permits forward movement of such projectile. At the same time the forward movement of the barrel permits pressure gas to enter the ports 148 in the barrel since the O-n'ng 42 is moved forwardly out of its former sealing engagement with the inner bore 24 of the rear bushing 20. Sincer the front projectile 126 is no longer restrained by the lingers 124, and since gas pressure exists behind it, the projectile moves forward into the position seen in Fig. 5, where it is just entering the tube 66 of the front section of the barrel 40. The strength of the spring 130 urging the projectiles 126 forwardly is relatively weak and hence the second projectile is not immediately moved forwardly when gas pressure behind the first projectile moves the latter into its position of Fig. 5.

Continued forward movement of the barrel 40 from the position of Fig. 5 brings the parts into the position seen in Fig. 3. The forwardly extending arms 11S of the tubular member 116 are now cammed back into their inner positions by reason of slidably contacting the forwardly extending sleeve 64 of the barrel extension 60. Thus the projectiles 126 which are still within the tube 116 are to a certain degree restrained from forward movement under the influence of the magazine spring 130 by reason of frictional engagement between the cylindrical side wall 127 of the projectile and the inner surfaces of the resilient arms 118. The forward movement of the barrel has by this moment also completely uncovered the ports 148 formed in the side wall of the barrel, thus permitting free entrance into the barrel of pressure gas within the chamber 102. The front bushing member 22, further compresses cumulator spring 36, under the force of the gas pressure within the chamber 102 exerted against the rearward annular face 104 of the bushing member, since the annular collar ring 48 moves forward with the barrel. The recoil spring 50 is also compressed by the forward movement of the barrel.

A moment following the point in the cycle shown in Fig. 3 the pressure of the gas within the chamber 102 commences to decrease. This is because of the fact that the gas within chamber 102 is being permitted to escape through the ports 148 formed in the barrel, and gas is being resupplied to the chamber 102 from the container 90 only through the relatively small orifice or port 93. It may be here noted that no gas escapes rearwardly, since O-ring 117 engaging tube 116 prevents this and the threaded engagement 136 of cap 134 is virtually gas This outward movement of the 4, as soon as gas pressure within the chamber 102 suffi-l ciently decreases, the front bushing 22 is forced rearwardly by the cumulator spring 36 to decrease the volume of the chamber 102 and thus to tend to maintain the gas pressure high within that chamber and, via ports 148, also within the barrel. In Fig. 4 this situation is shown and it is especially to be observed that the sleeve portion 26 of the front bushing 22 is no longer in abutting contact with the ring collar` 48 carried by the barrel. Nevertheless, the barrel 40 does not immediately move rearwardly even though the force of the recoil spring 50 urges it rearwardly. This is for the reason that the momentum of the forwardly moving barrel 40 and barrel extension 60, in view of the high speed at which the actions described herein take place, is sufficient to momentarily resist the rearward forceof the recoil spring 50. It will be seen, however, from` a consideration of Fig. 4 that eventually the recoil spring 50 will absorb the force resulting from the momentum of the forward movement of the barrel and barrel extension, and will return those parts to their rear positions. This is accomplished in the present mechanism by reason of the fact that only a small gas pressure can build up withinchamber 102 so long as the barrel 40 is substantially forward of its rearinost position and hence permits escape of pressure gas from chamber 102 through the ports 148 and thence outwardly through the barrel 40. The last portion of thek rearward movement of the barrel 40 serves to reestablish the hermetic seal existing between the sealing means 42 and the inner bore 24 of the rear bushing member 20, and the parts then come to rest in thc position of Fig. 2. It will be understood that during the rearward movement of the barrel from the position ot' Fig. 4 back to the position of Fig. 2, the arms 11i? of the feeding magazine are permitted to momentarily spring outwardly (when the parts pass through the position seen in Fig. 5) and thus to permit forward movement of the front projectile 126 into abutting contact with the inturned fingers 124 of the resilient arms, in position to be next red. e

Accordingly, it will be seen that there is here provided a gas-operated weapon for ring projectiles through a barrel and including resiliently biased pressure cumulator means for maintaining gas pressure at a high valuc throughout the movement of the projectile in the barrel and magazine feed means for introducing a projectile to tiring position at the appropriate point in the cycle. lt will be readily understood that the invention may be ap plied to a weapon other than a pistol if desired. lt will be further understood that auxiliary devices and equipment normally associated with a hand-operated weapon may be changed substantially from the illustrative forms typically shown herein without departing from the essence of the present invention as defined in the appended claims.

Those skilled in the art will recognize that the .above actions take place at high speed. T e cyclic rate of re of the present weapon is somewhat variable depending upon the gas pressure within container 90, the physical constants of the component parts and other factors. The cyclic rate ranges between about two hundred and four hundred rounds per minute under normal conditions.

I claim:

l. In a gas operated gun: a frame provided with a longitudinal chamber therein and a forwardly projecting tubular extension aligned with said chamber; a rear bushing in said chamber hermetically sealed with the frame and provided with a cylindrical bore therethrough and a forwardly directed annular face; a front bushing slidable within the frame and hermetically sealing therewith and provided with a cylindrical bore therethrough in coaxial alignment with said first named bore and having a rearwardly 4directed annular face; a 4barrel rslida'bly mounted for longitudinal movement -in said bores 'and hermetically sealing therewith; resilient means urging saidfront bushing rearwardly ytoward said rear bushing; the `outer surface 'of the barrel, the inner wall of the frame rand said `annular faces forming a variable volume compression chamber; means carried by the barrelfor positively limiting forward movement of the front bushing relative 'to the lbarrel; means for 'introducing gas under pressure into said compression chamber; said barrel including a front section and a `rear section, the rear section having a 'larger inside diameter than the front section and merging therewith in a rearwardly directed inclined annular shoulder, said rear section being provided with a port through the wall of the barrel yadjacent said shoulder; a loading tube lfixed relative to `the frame and projecting forwardly into and slidable within said rear section adapted to hold a plurality of projectiles, `the tube including forwardly projecting fingers having inturned tips, the fingers being resiliently biased outwardly and being cammed inwardly by sliding engagement with said shoulder; and resilient means urging the barrel rearwardly relative to the frame.

2. ln a gas operated pistol: a frame having a forwardly projecting support bearing; a barrel supported by said frame and bearing and longitudinally movable relative thereto between forward and rear positions, -said barrel having a front section provided with a longitudinal bore therein and a rear section provided with a second bore s coaxial with and of larger vdiameter than the first-named bore, said sections being joined by an internal annular inclined shoulder, the barrel being provided with a gas inlet port formed in the wall of the rear section; means for supplying pressure gas to the outer end of said port when the barrel is in its forward position; means urging the barrel forwardly relative to the frame; a feeding tube selectively stationarily attachable to the frame and including a front portion projecting into Vand sealing with the rear section of the barrel, said front portion including fingers resiliently biased outwardly and in slidable contact with the inner wall of said first-named bore when the barrel is in rear position, the tip portions of the `fingers being directed inwardly; means for latching the barrel in rear position; and selectively operable means for releasing said latching means.

3. In a gas operated weapon, in combination: a tubular barrel having a front section and a rear section, the rear section having a larger inside diameter than the front section and merging therewith in an inclined internal annular shoulder, the rear section being provided ywith a port through its -wall adjacent said shoulder; a rear bushing having a forwardly directed annular face and a cylindrical bore hermetically and slidably encircling the barrel; a front bushing `having a rearwardly directed annular face and a cylindrical bore lhermetically and slidably encircling the barrel; housing means hermetically Vsealing `with and encircling said bushings and forming therewith and with the barrel a compression chamber, the housing means being provided with an inlet port communicating with the chamber for supplying pressure Igas thereto; and a feeding tube Xed relative to the housing means 4and projecting forwardly into the rear section of the barrel, the feeding tube being adapted to contain a plurality of projectiles and resilient means for urging the projectiles forwardly, the feeding tube `including outwardly biased, inwardly directed movable retaining means cooperating with the iuternal `shoulder ofthe barrel for holding projectiles in the tube when the barrel is in rearmost position relative tothe housing means.

4. In a gas operated object propelling mechanism: a tubular barrel having a front object emitting end and a rear end and a radially disposed gas inlet port intermediate the `ends; a feeder magazine extending forwardly into the barrel from the rear end thereof and longitudinally slidable therein, the magazine being adapted to contain a plurality of propellable objects and including means for urging said objects forwardly and forwardly disposed outwardly biased, radially movable means for releasing an object upon outward movement thereof; the barrel being formed Awith 'an enlargement therein forwardly of said port for permitting outward movement of said outwardly biased means upon forward longitudinal movement of the barrel relative to the magazine; and means for introducing pres sure gas through said port rearwardly of the frontmost object upon outward movement of said outwardly biased ll'leallS.

References Cited in the le of this patent UNITED STATES PATENTS 2,048,061 Donato July 21, 1936 2,673,557 Shermanret al Mar. 30, 1954 2,688,321 Martin Sept. 7, 1954l

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