US2101862A - Gas-operated gun - Google Patents

Description

Dec. 14, 1937. s. H. M GREGOR GAS OPERATED GUN Filed April 22, 1956 \N mm mm mm KN MN Patented Dec. 14, 1937 UNITED STATES PATENT orrlce 3 Claims.

'(Granted under the Act of March 3, 1883, as amended April 30, 1928; 370 G. 757) The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to and is an improvement on gas-operated guns.

In guns of the gas-operated type, a piston movable by the gases of discharge is directly connected to an operating rod or actuator which by its movement unlocks the breech bolt. The sudden blow imparted to this type of rod or actuator may result in damage and breakage of the rod or actuator and of the bolt locking mechanism. Furthermore, at the moment of unlocking and opening of the breech the pressure therein is high.

Extraction of the cartridge case under high pressure may be difiicult, resulting inruptured cartridge cases or torn extracting grooves.

The purpose of this invention is to provide a delay action without loss of actuating power, and to apply the necessary power smoothly without violent or sudden contact of moving parts.

To these and other ends, the invention consists in the construction, arrangement andcombination of elements described hereinafter and pointed out in the claims forming a part of this specification.

A practical embodiment of the invention is illustrated in the accompanying drawing, wherein:

Fig. 1 is a view in side elevation of a gun.

Fig. 2 is an enlarged view partly in side elevation and partly in section and showing the parts in the normal action closed position.

Fig. 3 is a similar view showing the parts at 5 the start of the closing movement of the bolt from the full open position.

Fig. 4 is a transverse sectional view taken generally on the line 4--4 of Fig. 2 and showing the breech bolt in locked position.

Fig. 5 is a plan view of the front part of the breech bolt.

Fig. 6 is an enlarged view in side elevation of the handle piece of the breech-operating rod.

Fig. 7 is a sectional view on the line 11 of Fig. 6.

Referring to the drawing by characters of reference there is shown a gun barrel 5 threaded or otherwise secured in the front end of a receiver frame 6. A breech bolt reciprocally mounted in the receiver is formed with laterally extending wings, the left wing 8 having a pair of lugs 99 adapted, in breech-locking position, to enter recesses Ill-40 in the receiver and the right wing H, adapted, in breech-locking position, to enter 55 a slot l2 in the receiver, and having a cam memher l3 projecting beyond the side of the receiver. The bolt is unlocked by a rotary motion, and during reciprocation the lugs 9-4! ride a guide way l4 while the right wing ll rides over the upper edge of the corresponding side of the receiver. 5?

A cylinder l5 carried by the barrel 5 underneath its front part receives a portion of the gases of discharge through a port i 6 at the muzzle of the barrel. A hollow piston I! working in the cylinder has an open rear end for receiving the front 1 part of a hollow rod I 8 which in the normal position of rest of these elements has its front extremity spaced. a slight distance from a. plug 19 closing the front end of the piston. A helical spring 20 is confined between the plug 19 and a The piston llhas a collar 25 on its rear end for 20 engaging the rear edge of the cylinder l5 and limiting forward movement of the piston. The collar 25 is also arranged to engage a collar 25 on the rod. l8- when the piston moves rearwardly and takes-up'the distance between its plug l9 and the 25 front end of the rod l8. The rod I8 is held in place by a latch 21 during the initial and independent rearward movement of the piston. The latch is carried by a stationary element, such as the stock 28, and is held by a. spring 29 with its 30 end 30 normally in position to engage a lug 3! on the rod [8. The engagement between the latch end 30 and lug 3| is of a readily releasable type capable of being released when sufiicient force is applied to the rod l8 during manual retracting thereof.

An ofiset finger 32 on the rear end of the piston is arranged to trip the latch 21 when the collar 25 of the piston picks up the collar 26 of the rod. The rear end of the finger is provided with a lug 33 adapted to engage the rear face of the collar 26. This provision is made so that when retraction is to be accomplished by manually acting on the rod l 8 the piston will be carried along, (Fig. 2) and also for the purpose of limiting the independent counterrecoil movement of the piston under the influence of its spring 29.

An offset handle piece 34 on the rear end of the rod I8 is disposed alongside the receiver and has a stud 35 riding in a guide groove 36 in the receiver. The handle piece is formed with a. recess 3! having a front cam surface 38 and a rear cam surface 39. The projecting cam member E3 on the right wing of the breech bolt is disposed in the recess 31. When the rod I8 is moved rearwardly,

rod I8 under influence of its spring23.

The handle piece 34 is provided with a handle 48 whereby the rod I8 is manually retracted to initially load a cartridge into the'chamber of the gun barrel.

piston I'I move together by virtue'of the coupling between the lug 33 on the finger 32 of the'piston During this operation the rod I8 and and the collar 26 on the rod I8. The force applied to manually retract the rod, I8 causes the latch 2'! to be disengaged from the lug 3I.

When the gun is fired, a portion of the gases of discharge enters the cylinder I 5 and drives the piston I I rearwardly. Since therod I8 is held by the latch 21, the initial and independent movement of the piston compresses the spring 20. When the piston has moved about three quarters of an inch it disengages the latch 21 from the rod I8 and picks up the rod, which is driven rearwardly. The, initial movement of the rod I8 unlocks the bolt '1, after which it is'moVed-to the rear so that it may perform its usual functions as well understood in the art; The spring 23 which is energized during retraction'of the rod restores the parts into battery, the cam member I3 of the bolt limiting forward movement of the rod I8 while the piston continues forward under the influence of its spring. I

The piston takes the initial blow and insures a smooth movement of the rod I8 so that the parts will not be damaged or broken during the unlocking of the bolt I.

I claim:

receiver, a breech bolt reciprocable in the receiver, means whereby the bolt is locked to the With the bolt locked, the cam member I3 limits forward movement of the receiver", a cylinder fixed to the barrel, a gas pas"- sage between the barrel and cylinder, a piston in the cylinder, a collar on the rear end of the piston and engageable with the cylinder to limit forward movement of the piston, an offset finger extending rearwardlyrfrom the piston, a bolt-0perating rod having its front part slidable within the piston and adapted to be engaged and moved rearwardly by the piston, a spring seat in the rod, a driving spring for the rod, a spring between the spring seat of the rod and the front end of the pistoma collar fixed on the rod and movable between the end of the piston and the end of the finger 'of the piston, a latch releasably engaging .the rod.to hold it against rearward movement,

receiver, a breech bolt reciprocable in the receiver, means whereby the bolt is locked to the receiver, a cylinder fixed, to the barrel, a gas passage between the barrel and cylinder, a piston in the cylinder, a bolt-operating rod having its front part slidable within the piston, said piston and rod having a'small relative movement before the piston engages the rod to move it rearwardly, a spring seated on the rod and acting on the piston to hold it in advance of the rod, a driving spring for the rod, a latch releasably engaging the rod to hold it against rearward movement; and means whereby the piston controls the latch.

3. in a gun, a receiver, a barrel fixed to the receiver, a breech bolt reciprocable in the receiver, means whereby thebolt is locked to the'receiver, a cylinder fixed to the barrel, a gas passage between the barrel and cylinder, a piston in the cylinder, a bolt-operating rod having its front part slidable within the piston, said piston and rod having a small relative movement before the piston engages the rod to move it rearwardly, a spring seated on the rod and acting on the piston to hold it in advance of the rod, and a driving spring for the rod.

' STEPHEN H. MACGREGOR.

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