US2296834A - Pneumatic gun, bellows type - Google Patents

Description

Sept. 29, 1942. A. BoYNToN 2,296,834

PNEUMATIC GUN BELLows TYPE Filed May 18, 1959 3 Sheets-Sheet l mm l BY X ATTURNEYS.

Sept. 29, 1942. A. BOYNTON 2,296,834

PNEUMATIC GUN BELLOWS TYPE Filed May 18, 19.]39 3 Sheets-Sheet 2 35 ALEXANDER BOYNTON INVENTR,

15b m gg BY Wf@ Cw@ ATTORNEYS.

Sept. 29, 1942. A. BoYNToN 2,296,834

PNEUMATIC GUN BELLOWS TYPE Filed May 18, 1959 3 sheets-sheet s ALEXANDER BOYN TON, INVENTORY A TTORNEYS,

Patented Sept.. 29, i942 UNITED STATES PATENT OFFICE 2,296,834 PNEUMATIC GUN, BELLoWs TYPE Alexander Boynton, San Antonio, Tex.

Application May 18, 1939, Serial No. 274,365

6 Claims.

My invention relates to guns using compressed air or other gas or gas forming liquids or semiliquids as the expulsion means for discharging bullets, explosive cartridges, or bombs which may be filled with picric acid, ammonium nitrate, ammonal, or any other suitable explosive.

An object of this invention is to provide a means in warfare for accurately and rapidly throwing explosive cartridges for considerable distances without serious danger of projectiles being prematurely detonated within the gun.

Another object of this invention is to provide means for driving tunnels into rock without necessity for the usual slow and laborious method of drilling holes for explosives, and for doing the preliminary blasting for roads up mountain sides by firing explosives from aeroplanes.

In carrying out this invention, I employ a. metallic bellows hermetically sealed at both ends, one end being anchored and the other end free. Upon the free end of the bellows, I mount a valve that controls the discharge port of the chamber that houses the bellows assembly. Upon the free end of the bellows is also mounted, by means of suitable connections, a sleeve to which is attached a valve that controls the intake port of the chamber that houses the bellows assembly. These valves move in unison; one opening as the other closes, and vice versa. The bellows is partially lled with a liquid to protect it from being damaged by excessive external pressure. This liquid is also used to lubricate a latch and other moving parts within the bellows assembly. The latch is employed to make the valve action snappy.

A tubular magazine is provided to contain the projectiles, which are moved by a coiled spring and ratcheted shaft to successively contact a flexible member of restricted diameter at the breach, one projectile being forced through this exible member and out of the gun barrel by each blast of compressed air released by the discharge valve. This occurs as often as a predetermined external pressure is exerted upon the bellows by compressed air or other gas from an external source admitted into the chamber surrounding the bellows. The rate of gun lire is regulated by the rate at which this pressure is admitted. The force of the projectiles is determined by value of the pressure iluid employed to expel them and by the force required to expand the ilexible member.

Other objects and purposes will appear from the following description and specification of the mechanism illustrated in the accompanying drawings in which:

Fig. 1 is a plan view oi.' a gun embodying the invention.

Fig. 2 is a rear end View of the gun as shown in Fig. 3, except the mounting is omitted.

Fig. 3 is a side view of the gun showing it mounted and with an air connection attached.

Fig. 4 is a front end view of the gun shown in Fig. 3, except the mounting is omitted.

Fig. 5 is a broken longitudinal section of the rear portion of the gun with an air connection attached.

Fig. 6 is a broken longitudinal section of the front portion oi the gun, completing the view shown in Fig. 5.

Fig. 7 is a cross section on the line 1 1, Fig. 5.

Fig. 8 is a transverse section on the line 8-8, Fig. 5.

Fig. 9 is a cross section on the line 9 9, Fig. 6.

Fig. lo is a cross section on the line |0|0, Fig. 5.

Fig. 11 is a transverse section on the line Il-I l, Fig. 5.

Fig. 12 is a transverse section on the line |2-l2, Fig. 5.

Fig. 13 is a view partly outside and partly in longitudinal section of the arc ring member of the latch assembly.

Fig. 14 is a view partly outside and partly in longitudinal section of the pawl holder and associated parts, on the line "-44, Fig. l1.

Similar characters refer to similar parts throughout the several views. Different portions of the same part are referred to by adding a, b, c, and so on (small letters) to the number employed to designate the part as a whole. 'A portion of a portion is referred to by adding a numeral to the letter following the characters designating the larger portion. Duplicate portions of any part are designated by priming the last letter of reference for the duplication.

Referring to Figs. 5 and 6, the case l is closed at its rear end by threadedly connected plug 3 closing upon packing 4. A valve seat 3a is formed around the forward end oi' passage 3b the rear end of which communicates with an opening through an internally threaded boss 3c to which may be joined connection B of exible air hose C. The forward end of case I is threadedly joined to boss 27 of front end member 2, the joinder being secured by lock ring 39 closing upon packing 40.

Plug 3 has a forward extension formed by two semicircular projections 3d separated by two longitudinal slots 3e which provide space for the travel of arms Mb. The forward ends of projections 3d are internally threaded to engage bellows base holder 5, the circularly beveled lip a overlapping the oppositely beveled forward ends 3f of projections 3d, thus to prevent the arms from spreading as the threaded engagementis tightened between them and member 5 into the forward end 5c of which arc ring member 6 is pressed and held by bellows rear end connection 1 The segmental portions 6a of the arc ring member are rmly held upon the shoulder 5b by the member 1 having its anchor foot 1a soldered or welded to the bellows at 1b. In this manner the arc ring 6e is positioned and held central of and axially aligned with the members 5 and 1. The bellows 8 is soldered at 1b to the member 1 and is soldered to the forward end connection 9 at 9b the anchor foot 9a being to securely engage the solder.

Air valve carrier I Il has a rear extension lIlc threadedly connected to the member 9 locked upon packing 63 and further secured by solder or weld 9d. Valve Il is threadedly engaged with extension IUb locking internal circular flange I2a of valve stroke adjusting plug I2 between members ID and II. It will be noted that valve II normally lands upon a seat 2b immediately forward of the ports 2d of extension 2c within which the valve has a working fit.

The front end of the valve assembly is supported and guided by the tubular portion 2c of the member 2 from which the discharge valve II is not completely withdrawn when the intake valve I5 is seated.

Plug I2 is threadedly engaged within the forward end of valve carrier sleeve I3 which sleeve has two slots I3a in its rearward end into which the arms Idb of intake valve carrier bar I4 are welded at I4c, see Fig. 12. The threaded extension I5a of intake valve I5 is centrally engaged with the circular central portion Ida to support valve I5 directly forward of its seat. Pin I5b of the intake valve I5 has a close fit within port 3b to insure a sufficient closure of this valve in case of wear or a temporary lodgement of a foreign substance upon the seat 3a.

Interior of the bellows B and its forward connections 9 and I0, the upper tubular end I1 of latch shaft has threaded engagement with the internal threads of latch anchor plug I6 which, in turny is threadedly engaged with the rear internal threads of member 9. The tubular end I1 is internally threaded at its rear end to engage the threaded front end of latch shaft I8. Over the rear end I8b of this shaft, ball roof 2!! has a close fit and is urged against shoulder I8a by the force of spring 23 urging latch balls 22 and ball floor 2I forwardy the latter member having an easy working t over the shaft portion Ib upon the rear end of which nut 24 and lock nut 25 have threaded engagement for the purpose of regulating and securing proper compression of spring 23. The thin and slightly yieldable flanged portion 25a causes the locking engagement between nuts 24 and 25 to be more secure.

A guide pipe 26 preferably polished inside and outside has an easy working fit within the bellows and over spring 21. A cap 26a has its rear portion of slightly reduced diameter pressed into the upper forward end of guide pipe 26 to which it may be further secured by welding as shown at 26C. The forward end of the cap rests upon the plug I6 and the rear end of the guide pipe has a working fit over the spring shoe support 30 the 75 foot 30a of which lands upon an internal annular shoulder 1d of the member 1. The forward end of member 30 supports the spring rear shoe 29 the outside diameter of which is somewhat smaller than the inside diameter of guide pipe 25, the forward spring shoe 28 being supported by cap 26a.

The purpose of the bellows 'is to provide a resilient pressure responsive means, stationary at one end and movable at the other end, for operating the valves by varying the external prcssure upon the bellows. The spring 21, always installed under some compression, is to afford proper resistance to the longitudinal compression of the bellows in order to cause it to shorten a certain distance under a given force, and may be adjusted to actuate the valves at any desired pressure, opening valve II and simultaneously closing valve I5 at one pressure exterior of the bellows; and then at a predetermined lower pressure to simultaneously close valve II and open valve I5 by aid of the latch as will be explained. The guide pipe 26, polished inside and out, affords a barrier between the spring and bellows thereby preventing the coils of the spring from engaging with corrugations of the bellows as the assembly alternately expands and contracts in operation.

It will be noted that the rear end of the guide pipe 26 extends behind the bellows and spring 21 in order that the end of this pipe may likewise not engage with the spring coils within or the bellows corrugations without. When the valves are adjusted care must be taken that there is left enough room between the rear end of the spring shoe support 30 and the foot 30a thereof to allow valve I5 to seat. Strengthening spring 21 will increase this distance, and vice versa, at any particular opening pressure of valve II.

The purpose of valve carrier sleeve I3 is to transmit movement from the upper end of the bellows to valve I5. The purpose of the latch is to afford snappy action of the valves in either or both directions, that valve movement once begun will be instantly completed. The latch converts delayed valve action into quick action. Spring shoes 28 and 29 over` respective extensions of which spring 21 fits tightly, add to the smoothness and sensitiveness of the latch action by providing bearings to accommodate the slight axial movement of the spring as it contracts or elongates.

Latch shaft I8 should be so adjusted by means of the threads on tubular end I1 engaging within the threads of plug I6 and lock nut I9 that the latch balls 22 will roll slightly over and engage upon the forward arcuate end 6c of the arc ring 6 when valve II is closed and valve I5 is open as shown in Fig. 5. The latch balls should roll slightly over and engage upon the rear arcuate end 6d of the arc ring when valve II is open and the other valve is closed.

It will be noted that the length of arc ring 6c is such as will allow the latch balls to roll slight- 1y over the curved surfaces 6c and 6d as the valves alternately assume extreme forward and backward positions respectively. Manifestly the further the latch balls roll outward upon the forward curved surface 6c the more resistance will be offered by the latch to the opening of forward valve II and the closing of the rear valve I5; and likewise the further the latch balls roll outward over the rear curved surface 6d the more resistance will be offered by the latch to the closing of valve I I and the opening of valve I5.

The latch should be so adjusted as to afford snappy valve action in both directions, it being desired that both valves should close with a slam. Increasing the compression of adjusting spring 23 causes the latch to holdwith greater force at a given travel of latch balls over the surfaces 6c and 6d, and vice versa.

The latch balls are urged outwardly by the oppositely inclined surfaces 20a and 2Ia of the ball roof and floor respectively, the extreme outward movement of the balls being limited by the concaved lips 20h and 2lb of the roof and floor respectively. Manifestly if the pitch toward the axis of the latch shaft of the inclined surfaces contacting the balls be increased, the outward thrust upon the balls will be increased, and vice versa. In rolling over the forward arcuate surface 6c the latch balls will hold the valve II resiliently closed against an opening force that would open this valve except for the latch; and in rolling outwardly over the arcuate surface 6d the latch balls urge the valve I I to remain resiliently open against a closing force that would close this valve except for the latch.

At any given expansive force exerted by the latch spring 23 the further the latch balls roll outward upon either arcuate surface the more resistance to valve movement in the direction of the other 'arcuate surface is offered by the latch, and vice versa.

It will be understood that the chamber interior of the bellows and its forward and backward extensions is hermetically sealed by solder or welds 3Ia, 1c, 1b, 9d, packing rings 63 and 33, and by plugs 3| and 32. It is necessary that the bellows be hermetically sealed in order that the bellows will be and remain responsive to external pressures.

The bellows chamber should be partially lled with a lubricant such as oil r glycerine. An air pocket or partial vacuum of sufficient length must be provided in the chamber above the lubricant to allow the bellows to contract enough to seat valve I at a predetermined external pressure upon the bellows. The space above the lubricant it being assumed for convenience of illustration that the gun is pointed upward) should allow valve I5 to close'before the roof of chamber Illa would impinge upon the lubricant. This provides that the remainder of this space above the lubricant will be closed upon by the outward compression of the bellows corrugations as the folds are forced together by external pressure. In this manner, the external and internal pressures are kept equal except for the force required to compress spring 21 and the bellows.

The bellows will, therefore, never be ruptured by an external force no matter how great so long as the force required to compress spring 21 is less than the force necessary to rupture the bellows. Longitudinal passage I1a and horizontal openings I1b of latch shaft sub I1, slots I8c of latch shaft I 6, perforations 3012 of the spring shoe support 30, slots 26b of the guide pipe 26, and openings 6b 0f the latch ring member 6 provide for the free circulation of the latch lubricant without which provision the latch operation would be impeded.

In this connection it should be recalled that both valves are secured to valve carrier sleeve I3; the forward valve being secured to this sleeve by ange I2a locked between the valve II and its connection member IIJ, and the rear valve being secured to central enlarged portion Ila of valve carrier bar I4 which, in turn, is secured to the rear end of sleeve I3. It should further be borne in mind that the bellows is held stationary at its rear end -by means of the threaded engagement between bellows base holder 5 and projections 3d as may be .seen in Fig. 5. This xed position of the bellows at one end while the other end ls free causes all the bellows movement to take place at the free end which controls the valve movement, Iboth valves being mounted uponl parts secured to valve carrier sleeve I3 as before stated, and as appears in Figs. 5 and 6.

The valve stroke may be increased by screwing the case I outward on boss 27'. and vice versa. The valve stroke may also be increased by screwing adjusting plug I2 in the direction of valve I 5 within sleeve I 3, and vice versa.

The first means of increasing the valve travel lessens the pressure required to open valve II while the second means causes no change in this pressure. Whether the valve travel rbe adjusted in one way or the other, it will be necessary to adjust the position of the latch balls accordingly by screwing shaft sub I1 up or down as the case may require if the same latch adjustment is desired.

The relation between the volume of lubricant and the volume of air space within the latch chamber and the pressure within the air pocket is important in determining the value of the external Apressure required to open valve II. If this air pocket is large little building up of pressure within the pocket will result from the bellows compression necessary to seat valve I5. The latch action holding valve II closed with enough force to slam valve I5 closed when valve I I opens will, therefore, be less if this space is large than if the space be small. If valve I5 is to slam closed when valve I I opens it is apparent that the latch must hold valve I I resiliently closed with enough force to overcome the build up of pressure within the air pocket in the latch chamber plus the force required to compress the bellows and bellows spring the full distance of the valve travel.

It will now be apparent that a partial vacuum instead of a compressed air pocket within the latch chamber will lessen the pressure build up during the opening of valve II and the closing of .valve I5. For thev purpose of varying the pressure within the latch chamber valve 62 is provided. Air or other gas may be `pumped in and the latch chamber sealed by use of valve 62, plug 32, and packing 33, or the latch lubricant may through the same openings be increased or diminished. If a partial vacuum is desired, remove plug 32, hold valve 62 open, and compress the4 bellows until the air in the pocket within the latch chamber is diminished to the desired volume or wholly expelled, screw plug 32 down rmly upon packing 33 and allow the bellowsto expand. A partial vacuum will result within the latch chamber the degree of vacuum depending, of course, upon the expansive force of the bellows and spring 21. I

A barrel 34 having a central bore 34C of very slightly larger diameter than the diameter of the cartridges in magazine 5I is supported upon flanged front end 2k of the forward end of bracket 2n and transverse rib ZnI to which flanged front end it is clamped by upper bracket half 66, the clamp being secured by belts 6l and nuts 65. The barrel is locked against rotation by key 61 tted within slot 34d. It will be noted that slot 34d is of sufficient length to allow yieldable member 35 to be compressed or allowed to expand by screwing resistance adjuster 36 in or out. This feature of the present disclosure constitutes a feature of novelty in my copending application for Pneumatic gun, Serial No. 267,194, filed April 10, 1939.

The rear end of the barrel is secured rwithin externally threaded boss 2f 4by flanged cap resistance ring adjuster 36 adapted to engage upon boss 34a so as to compress resilient resistance ring 35, which may be of rubber or any other tough and resilient substance, between the annular inclined surfaces 2r and 34h until the central passage through it is reduced thereby to a diameter appreciably less than the diameter of the cartridges. By this means the forward cartridge 52 in bore 2e registering with the bore 34e is restrained from further forward movement in the position shown in Fig. 6 until a predetermined force sufilcient to overcome the resistance offered by ring 35 is exerted behind this cartridge.

Magazine welded at 2g into the bore 2m and again welded at 38d into a bore through the upper portion of mounting band member 35 carries cartridges 52, 52', I52", etc., within its smooth bore of only slightly greater diameter than the diameter of the cartridges. The cartridges are aligned by pins 52h fitting into circular openings 52a. An expanded front end 53a of spring housing nipple `53 slips snugly over the rear end of magazine 5|, the rear end of nipple 53 having threaded engagement within spring retainer cap 55 over the rear end of which cap the forward end of Octagon portion 56a| of cap 55a has threaded connection, the rear end of cap 55a being welded at 55e to ratchet housing 55.

Sleeve 56h is pressed over the rear end of housing 56 to which it is welded at 55e'. Clamp 48 secured upon shell by ibolt 49 engaging upon flange 48d and nut 50 engaging upon flange 43d' has an extension 48h through which a bore provides a working iit for sleeve 55h. The two halves 4| and 42 of another clamp (Figs. 5 and are secured together by bolts 45 and nuts 41 as is apparent. The clearance 42a provides that the clamps 4| and 42 will securely engage upon case I.

A portion of the member 4| has integral with it two posts 4|a and 4|b. Hinged upon post Ila by means of lock lever stud 44 is a lock lever 43 having a handle extension 43a, the hinge being formed by bushing 45 clamped by stud 44 engaging within a threaded opening in the enlarged end 4|d of post 4Ia. This lever has two forks 43h and 43e which engage upon the sloping circular surface 56112 (Fig. 5) which engagement urges the annular internal shoulder 53h against the rear end of magazine 5I. This engagement should occur when the lock lever 43 is approximately horizontal as shown in Fig. 10. The locking effect is produced by the friction engagement between the lever forks 43h and 43e and the sloping surface 56a2, the lever being guided and supported by post 4Ia as appears in Figs. 9, 10, and 11. The Octagon portion 5$a| rests in and is held from turning by the Octagon trough 4Ic. The lock thus produced secures the spring housing 53 and the ratchet housing 56 in the position shown in Figs. 1, 3, and 5, this being the position in which the gun is ready to begin firing as will be explained. The spring 54 has its forward end engaged upon a head 51a of the forward portion 51h of the ratchet member 51 and its rear end engaged within the flanged portion of pawl housing cap 56a.

This spring is installed under enough compression to urge the rearmost cartridge 52" to engage expansible ring 35 after all the other cartridges have been expelled as will be explained.

The rear end of ratch I1 has a longitudinal slot 51! into which fits the rectangular end lla of ratchet handle Il and into which it is secured by rivets 51g. A longitudinal slot 55! in one side of ratchet housing 55 affords a free sliding fit for rectangular portion 55a of the ratchet handle 5l. 'I'his slot is of such length that the ratch may follow the cartridges until the last one has been discharged from the magazine 5|. Within the chamber "al, having a slot "a4, is positioned a ratch holder or pawl composed of upper half 5l, 4lower half Il and spring 5I. The halves 55 and 55 are fulcrumed, one upon the other, by male bearing 55a resting within female bearing 50a. The blades 59h and IIb are urged toward each other by circular spring 5| the opposite ends of which nt into depressions 59e and 60e respectively, the spring being held axially of the pawl assembly by the slots 59d and 50d. It will be noted that the transverse slot 55a4 is long enough and of such shape as will allow the pawl handles 59e and 50e to be compressed together close enough to cause the blades IIb and 50h to part far enough to allow the ratch portion of member `51 to pass .between the blades, the chamber 55a3 being large enough to allow for the necessary expansion of circular spring 8| as it enlarges when the blades 55h and "b are forced apart.

It will be further noted that the blades conform in shape to the interdental spaces 51e of the ratched portion 51c. The ratch may, therefore be forced forward through the ratchet housing 55 but the ratch can not be forced backward unless the handles 53e and 55e of the pa-wl be pressed together far enough to force the blades 59h and 50h completely out of engagement within the interdental spalces 51e of the ratcheted .por tion 51e.

The spring 54 is strong enough and will -elongate far enough to pull the ratch forward through the rpawl as the cartridges are successively discharged from the barrel.

'I'he gun may be mounted upon a tripod as shown in Fig. 3, by attaching the connection 2h by means of bolts or pins through the openings 2q in mounting extension 2h and IIb in arms 38e. The mounting, drawn to a scale smaller than the gun, is indicated generally at M. This mounting, which will be recognized and understood by those skilled in the art, is no part of the invention. Front sight 31 and rear sight 35a provide means for aiming the gun, the direction being controlled by handles 45a and 43a' proximate the rear end.

The gun, shown loaded in Figs. 5 and 6 and mounted as in Fig. 3, is ready to -be fired. Compressed air or gas of proper value (depending upon the bellows and latch adjustment) is turned into flexible hose C by a valve not shown. It will be assumed that the bellows and latch a'ssembly is adjusted to open valve Il and close valve I5 at 500 lbs. pressure per sq. in. upon the bellows and that valve l5 will open closing valve Ii at 400 lbs. per sq. in. Pressure within the chamber 2p interior of case quickly builds up to 500 lbs. Valve opens with an instantaneous movement and valve 5 slams shut. The recession of valve Il opens ports 2d. The air under 500 lbs. pressure expands with explosive force into passage 2a and engages between cartridges 52 and 52' forcing cartridge 52 to stretch the expansible member 35 and be driven through the bore 34C, cartridge 52' being at the same V time held in the position shown by force of the 500 lbs. -pressure seeking escape backward through the magazine I and spring housing nipple 53. The force which drives cartridge 52 forward out of the barrel, acts with equal force tending to drive the other cartridges backward in the magazine, such backward movement -being prevented, however, by the ratchet. When the cartridge 52 passes out ont the barrel the air under 500 lbs. pressure instantly follows, and the pressure drops to 400 lbs. within the case I at which time the discharge valve II again closes while cartridge 52 moves up to the position from which cartridge 52 was expelled. All other cartridges within the magazine follow as a unit, due to the expansive force of spring 54 acting upon head 51a which causes the ratchet shaft 51 to move forward the length of a cartridge each time a cartridge is expelled. The cycle above described automatically repeats until all the cartridges have been expelled from the magazine or until the compressed air supply is cut olf.

The quick valve action as previously explained is caused by the latch which should in the present assumption of 100 lbs. diierential be set to engage somewhat more than one-half of the differential, say 70 lbs., in the forward position and 30 lbs. in the backward position. The reason for adjusting the latch to hold more than half of the 100 lbs. di'erential against the opening of valve I I is that valve I5 must close against the pressure in supply hose C as well as against the expansive force of spring 21. Less latch force should be employed against the opening of valve I5 because valve iI is sided in closing by both of said forces which resist the closing of valve I5.

To reload assuming the gun to -be held horizontally with the barrel above the member 2, press together the pawl handles 59e and 60e. Then pull backward the ratchet handle 58 closing space A until the rear end 51d strikes the closure 56g. Then turn the handle 58 to vertical position in transverse slot 55d and release it in upper slot 56e. Now raise lock lever 43 and turn the pawl handles 59e and 60e to vertical position and move the ratchet assembly backward until sleeve 56h is out of its holder 48h, at which time the enlarged end 53a has disengaged the rear end of magazine 5I. The ratchet assembly is then free to be removed, the slot 48e being somewhat wider than the outside diameter of the ratchet housing 56. The magazine 5I may now be refilled with cartridges. When this is done and the ratchet assembly is replaced, draw the handle 53 back out of upper slot 56e and rotate it 90 to its normal horizontal position in line with slot 561 and release it. This completes the reloading operation. The gun is ready to be iired again by opening the air valve on hose C as was explained.

The rate of fire may be increased by decreasing the difference between the pressures at which the valves will open and close, the latch assembly being a large factor in making such adjustments.

In rapid fire the resistance ring 35 will not be destroyed by heat due to the friction caused by the balls in rapidly iiexing this member because of the frigid temperatures produced by the rapidly expanding air at that point.

A lubricant, such as powdered graphite or a mixture of graphite and a liquid, that will not disintegrate the resistance ring 35 may be placed in the magazine 5I with the cartridges or broughtl ring 35 by a cup attachment or any other suitable lubrication means of which many are known.

Attention is called to the fact that resistance ring adjuster 35 is very accessible and may be screwed in or out by hand to easily and quickly regulate the projectile force. Holes 35a are provided, however, that a nail or rod may also be used for that purpose.

It is understood that the detailsl of construction and arrangement of parts are subject to many obvious variations and minor changes without departing from the scope and purpose of my invention as dened by the appended claims.

What is claimed is:

1. A pneumatic gun comprising a barrel, al magazine, means for feeding projectiles from the magazine to the breech of the barrel, a source of pressure iiuid, a case having a chamber with an inlet connected to said source and an outlet communicating with the breech, opposed valve seats one in each said inlet and outlet, a Valve assembly within said chamber, said assembly including opposed valve members adapted to be moved into engagement with either of said seats, and pressure responsive means within the valve assembly for moving the assembly between the seats whereby the projectiles which are fed successively to the barrel by said first mentioned means are forcibly ejected therefrom.

2. A pneumatic gun comprising a barrel, a magazine, means for feeding projectiles from the magazine to the breech of the barrel, a source of pressure fluid, a case having a chamber with an inlet connected to said source and an outlet communicating with the breech, opposed valve seats one in each said inlet and outlet, a valve assembly within said chamber, said assembly including opposed valve members adapted to be moved into engagement with either of said seats, pressure responsive means within the Valve assembly for moving the assembly between the seats whereby the projectiles which are fed successively to the barrel said first mentioned means are forcibly ejected therefrom, said last mentioned means comprising a xed member and a snap action mechanism connecting said member to the assembly said snap action mechanism being so constructed and arranged that the valve members are moved alternately by snap action into engagement with their respective valve seats.

3. In a pneumatic gun the combination of a barrel having a bore through which projectiles are to be discharged, a magazine, means for feeding projectiles in succession from the magazine to the breech of the barrel, a source of pressure iluid, means for applying an impulse of said pressure fluid to the projectile in the breech of the barrel, said last mentioned means comprising a case having a chamber, there being a rst passage between said chamber and said source and a second passage between the chamber and the breech of the barrel, and pressure responsive valve means within the chambe;` for alternately opening and closing each of said passages to iirst admit pressure fluid to the interior of said chamber and to thereafter close the first passage and open the second passage to admit, the entrapped pressure iluid to the projectile in the breech of the barrel.

4. In a pneumatic gun the combination of a barrel having a bore through which projectiles are to be discharged, a magazine, means for feeding projectiles in succession from the magazine to the breech of the barrel, a source of pressure uid, means for applying an impulse of said pressure iiuid to the projectile in the breech of the barrel, said last mentioned means. comprising a case having a chamber. there being a first passage between said chamber and said source and a second'passage betweenv the chamber and the breech of the barrel, pressure responsive valve means within the chamber for alternately opening and closing each of said passages to first admit pressure fluid to the interior of said chamber and to thereafter close the first passage and open the second pasage to admit the entrapped pressure fluid to the projectile in the breech of the barrel, and latch means for restraining the valve means from movement until a predetermined force is exerted thereon.

5. A pneumatic gun. comprising a barrel for discharging projectiles, a yieldable resistance ring at the rear end of said barrel to offer resistance to the passage of said projectiles therethrough, a magazine for projectiles secured on the rear end of and aligned with said barrel, means for feeding the projectiles successively to the breach of said barrel, said means being aligned with said barrel and comprising said magazine, a ratch and a spring, said ratch being urged forward by force of said spring, a shell secured upon said barrel and said feeding means, a connection having a passage between said shell and magazine at the forward end of each, said passage having one terminus proximate the forward end of said magazine and the other terminus formed into a seat within said shell, a plate across the other end of said shell, said Plate having an opening for pressure fluid axial of said shell, a pressure fluid conduit connected to said plate and adapted toA discharge pressure fluid through said opening, a valve seat surrounding the forward end of said opening, a pressure responsive assembly in said shell, said assembly being secured at one end to a forward extension of said plate and being free within said shell at CTI the other end, a tube surrounding said assembly and connected to said free end, an intake valve upon the other end of said tube, said valve being normally in spaced relation to said last seat but adapted to engage said seat and close said opening when the pressure responsive assembly is actuated, a discharge valve movable with the forward end of said tube, said valve being adapted to normally close said passage by engaging said first mentioned seat and to recede therefrom to open said passage when said pressure responsive assembly is compressed by fluid from said conduit, a latch in said assembly to resist the opening and closing of each of said valves and to cause same to alternately open and close quickly in response ao the varying force of pressure iiuid upon said pressure responsive assembly for the purpose of discharging pressure fluid between the two foremost projectiles in said magazine to expel from the gun the foremost projectile and to restrain from forward movement the succeeding projectile until such expulsion is completed, and means for thereafter moving the next projectile forward into contact with said resistance ring.

6. In a pneumatic gun, the combination of a barrel, a yieldable resistance ring surrounding the bore proximate the rear end of the barrel, a magazine for projectiles, means for feeding projectiles successively from the magazine to the reistance ring, a pressure responsive element, means operable by said element for admitting intermittent blasts of pressure uid to the breech of the barrel to expel the forward of said projectiles first and the others in succession, together with means for adjusting said resistance ring to vary the force for expulsion of the projectile therethrough, and means for adjusting the pressure responsive element so as to cause the same to be compressible by variable pressures and to be expansible under variable less pressures.

' ALEXANDER BOYNTON.

Images