US3255669A - Gas-operated firearm - Google Patents

Description

June 14, 1966 s. M. oLoFssoN GAS-OPERATED FIREARM 2 Sheets-Sheet;

Filed March 5, 1965 June 14, 1966 s. M. oLoFssoN 3,255,669

GAS-OPERATED FIREARM Filed March 5, 1965 2 Sheets-Sheet 2 United States Patent O 3,255,669 GAS-OPERATED FIREARM Sigfrid Marenus Olofsson, P.0. Box 5880, Munkedal, Sweden Filed Mar. 5, 1965, Ser. No. 437,480 7 Claims. (Cl. 89-7) This application is a continuation-in-part of my application for firearm for shooting practice, Serial No. 293,395, filed July 8, 1963, now abandoned.

The present invention relates to a firearm, in which explosive gas is compressed and ignited to impel the bullet from the barrel by the explosion and expansion of such gas.

In common with my said pending application the object of the present invention is to provide a firearm which is inexpensive in manufacture and operation and easy to manipulate.

Another object is to provide a firearm having a detonation chamber for compressed gas which by means of `a valve is separated from the barrel until the shot is fired so that a predetermined pressure will be maintained 'in said chamber.

Still another object is to provide a dosing mechanism so that a predetermined amount of gas will be obtainedin the detonation'chamber -in order to secure uniform charge.

Further objects will be apparent from the following description and claims, the description being supplemented by the accompanying drawing which forms part of this specification and in which:

FIGS. la and lb are longitudinal sections through the firearm, and FIG. 2 is a longitudinal section through part of the firearm showing the Ibreech block retracted.

The firearm comprises a barrel casing 1 which surrounds a grooved barrel 2. The barrel 2 is screwed into the breech case 3 of the mechanism. Slidably mounted in the breech case 3 is a breech block 4 having an ignition mechanism and a valve member to be described later on. Housed in the stock 5 of the firearm is -a gas container 6. A receptacle 7 for calcium carbide is insertable into the container 6 through a normally covered opening 8 in the rear plate 9 of the stock 5. A filler valve 10 for water extends through the rear plate 9 and is connected to the receptacle 7 by means of a hose 11. If water is supplied into the recep-tacle 7 containing calcium barbide 12 acetylene gas will be generated and flow into the container 6 through apertures 13.

Located in the container 6 is a dosing chamber 14 at one end provided with a tube 15 having a valve seat for a valve member 16 and supporting a gas filter 17, said valve member 16 ibeing connected -to a rod 18 extending through said dosing chamber 14 in its longitudinal direction and at the other end thereof connected to a diaphragm 19 forming a movable end wall of said chamber. A tube 20 having a non-return valve 21 extends from the dosing .chamber 14 to a valve body 22 inserted into a housing 23 beneath the breech case 3 and formi-ng a part thereof. To said housing a pump cylinder 24 is screwed and extends beneath the barrel 2 in its longitudinal direction. Into the pump cylinder 24 a plunger 25 is movable and connected to a hand grip 26 by means of a plunger rod 27. Near the outer end of the pump cylinder 24 apertures 28 are provided for the inlet of air into the pump cylinder when the plunger is in its outermost position and said apertures 28 are uncovered.

The Valve body 22 has a radial duct 29 at one end connected to the tube 20 and at the other end connected to a second longitudinal and central duct 30 which at one end is open into the pump cylinder 2 4 and at the other end leading into a chamber in the housing 23. The mouth of the duct 30 in said chamber is covered by 3,255,669 Patented June 14, 1966 ICC means of a cup-shaped valve member 31 forced to closing position by a spring 32 i-n which position the flange of the valve memlber 31 closes a duct 33 between said chamber and a detonation chamber 34 surrounding the end of the barrel 2 in the breech ease 3.

Mounted in the breech-case 3 is a retractable breechblock 4 consisting of a cylindrical bolt having a central passage for a-guide member 35 with capacity of reciprocation. The forward end of said guide member 35 is provided with a central bottom hole for the guidance of a sleeve 36 at the forward end supporting a valve member in which a packing disk 37 and the ignitor stone 38 of a rub ignitor are mounted. Said member and the sleeve are yieldingly mounted in the guide member 35 by means of a coil spri-ng 39 which at one end is fastened to the bottom of the bottom hole and at the other end to said valve member. In the 'breech-block 4 a saw-toothed bar 40 is mounted for cooperation with the ignitor stone 38. When the breech-block 4 is locked in the position shown in FIG. l the detonation chamber 34 is separated from the barrel by means of the packing disk 37 forced against the inner end of the barrel 2 by means of the spring 39. The spring 39 is loaded by a cocking piece 41 at the rear end of the breech-block 4 and the guide member 35 is provided with a cooking shoulder adapted to be engaged by a detent 42 on an arm 43 pivotally mounted in the breech-block 4. A spring 44 between said arm 43 and the breech-block 4 acts to keep the detent 42 in engagement with the cooking shoulder. Mounted for turning movement upon a reduced portion at the rear end of the breech-block 4 is a sleeve 45 with a handle 46. Said sleeve is provided with a locking-nose 47 which in the locking position of the breech-block is in engagement With a Catch on the rear end of the mechanism. When turning the sleeve 45 the engagement between the locking-nose 47 and the catch is released so that the breechblock can be moved rearwards as shown in FIG. 2.

The trigger 48 is pivoted intermediate its upper end 49 and its finger-piece by means of a pin 50 extending transversely through a lip depending from the mechanism. A spring 51 is inserted between the trigger 48 and the bottom of the mechanism and tends to swing the trigger in a clockwise direction. The upper end 49` of the trigger is provided with a hook cooperating with the end of the arm 43 when the breech-block 4 is in its locking position as shown in FIG. l. When pulling the trigger 48 said arm 43 is swung downwards and the detent 42 wi-ll release the cooking-shoulder of the guide member 35. Mounted on the trigger 48 is also a trip arm 52 which when the trigger is pulled will engage and lift a lug 53 secured to the diaphragm 19 and the rod 18 in the dosing chamber 14 thereby disengagi-ng a detent 54 in said chamber from the rod 18 and permitting said rod to move the valve member 16 to open position.

In order to obtain the desired pressure of the gas in the dosing chamber 14 the diaphragm 19 is tensioned more or less by means of an adjusting screw 55 which through a flexible linkage 56 comprising a coil spring 57 is secured to the lug 53. Said flexible linkage counteracts the movement of the diaphragm due to the pressure of the gas contained in the chamber 14.

The mode of operation of the firearm is as follows.

Calcium carbide 12 is placed into the receptacle 7 and water is supplied through the Valve 10 resulting in the generation of acetylene gas which lls up the container 6. Gas flows through the filter 17 and the open valve 15, 16 into the dosing chamber 14 and as soon as this chamber has been filled to a determined small pressure the valve closes and no further gas can enter the system. The operation of the valve member 16 is due to the fact that gas entering the chamber 14 acts upon the diaphragm 19 with the result that the rod 18 will be moved to the left until the valve member 16 is seated on the valve seat of the tube 15. At the same time the rod 18 will be locked in position by means of the detent 54 engaging a recess in the rod 13.

When a shot is to be red the breech-block 4 is pulled back and a bullet 53 is inserted into the bullet chamber in the `barrel whereupon the breech-block 4 is closed again and the spring 39 is loaded by the cocking piece 41. Thereby the detonation chamber 34 Will be closed from the barrel by the packing disk 37.

In order to charge a determined amount of combustible gas into the detonation chamber 34 the plunger 25 together with the plunger rod 27 is moved forward in the cylinder 24, so that a partial vacuum is created in the cylinder due to the fact that the pressure in the dosing chamber is only slightly above atmospheric pressure and the resistance to flow in the long and narrow tube 20 as well as the non-return valve 21 is considerable. Thus when the aperture 28 in the cylinder 24 is uncovered air can enter into the cylinder and mix with the gas drawn from the dosing chamber 14 through the tube 20 and the valve 21. The gas cannot escape out of said aperture as the pressure in the cylinder never will exceed the atmospheric pressure. When the pi-ston 25 is moved to the right the gas mixture in the cylinder 24 will be compressed and forced through the valve 31 and the duct 33 into the detonation chamber 21. At the end of the piston stroke the valve 31 under the pressure of the spring 32 returns to its closing position thereby shutting up the gas mixture in the detonation chamber 34. In case of a plurality of piston strokes the pressure in the detonation chamber will ybe further increased resulting in a higher discharging power.

When the trigger 48 is pulled the arm 43 will be swung so as t disengage the detent 42 from the guide member 35 and the pressure in the detonation chamber 34 forces the valve member with the packing disk 37 and the ignitor stone 38 backward so that the gas mixture escaping out of the detonation chamber 34 to the space in the barrel behind the bullet will be ignited and explosively burnt at a very high pressure to discharge the bullet out through the barrel.

Simultaneously as the shot is fired the valve member 16 is opened as stated above so that a new charge of acetylene gas can enter the dosing chamber 14. After opening of the breech-block 4 a new bullet can be inserted and the arm is again ready to be loaded and fired.

What is claimed is:

1. A gas-operated firearm comprising a barrel including a bullet chamber at its rear end,

a detonation chamber associated with said bullet chamber,

a container for a supply of combustible fluid,

a connection between said detonation chamber and said container including a manually controlled means for releasing a determined amount of said combustible fluid from said container, means for mixing such released amount of combustible liuid with a fluid oxygen carrier to form a charge of an explosive gas mixture and means for delivering such charge to said detonation chamber under a pressure greater than the atmospheric pressure,

a retractable breech-block located behind said bullet chamber and normally forming a wall of said detonation chamber,

a trigger mechanism,

means actuated by said trigger mechanism for igniting said charge,

and a spring-operated valve normally separating said i detonation chamber and said bullet chamber, said valve being built-in in said breech-block and forming said wall of the detonation chamber.

2. A firearm as set forth in claim 1 and further comprising a dosing chamber and a second valve operable to connect said dosing chamber with said container, said dosing chamber having a resiliently flexible wall portion mechanically connected to said second valve and controlling the opening and closing of said second valve in accordance with changes in the gas pressure within said dosing chamber.

3. A gas-operated firearm comprising a barrel including a bullet chamber at its rear end,

a detonation chamber associated with said bullet chamber,

a built-in device for generating gas,

a dosing device delivering a determined amount of gas at an adjustable pressure,

means for mixing a determined amount of air with the gas and for supplying the gas and air mixture in a compressed condition into said detonation chamber,

a valve for said detonation chamber,

said valve normally closing said barrel,

a mechanical ignition mechanism,

a trigger for tripping said mechanism,

a container for a supply of gas,

a dosing chamber,

and a second valve connecting said dosing chamber with said container, said dosing chamber having a resiliently exible wall portion mechanically connected to said second valve and controlling the opening .and closing of said second valve in accordance with changes in the gas pressure within said dosing chamber,

said mixing means consisting of a pump cylinder and a plunger movable therein, said cylinder communieating with said dosing chamber and having air inlet apertures which are uncovered by the piston in the outerm'ost position thereof to permit entering air to be mixed with the gas drawn into the cylinder from said dosing chamber.

4. A firearm as set forth in claim 1,

said 'breech-block comprises a guide member movable in said breechblock, and held by the trigger in a fore position,

and a spring inserted in said guide member and biasing said valve to closed position.

5. A firearm as set forth in claim 1, in which said means for igniting said charge consists of a rub ignitor comprising an ignitor stone mounted in said breech-block.

6. A firearm as set forth in claim 1, in which said valve is openable by the pressure of a gas charge contained in said detonation chamber when released by said trigger.

7. A firearm as set forth in claim 1, in which said valve is provided with a rst seat for said bullet chamber and a second seat for said detonation chamber.

References Cited by the Examiner UNITED STATES PATENTS 1,164,876 12/1915 Sayler 42-1 1,174,840 4/1916 Fisher 89-7 1,596,057 8/ 1926 Mallory 89-7 2,947,221 8/ 1960 Griffin et al 89-7 BENJAMIN A. BORCHELT, Primary Examiner.

R. V. LOTTMAN, Assistant Examiner.

Claims (1)

1. A GAS-OPERATED FIREARM COMPRISING A BARREL INCLUDING A BULLET CHAMBER AT ITS REAR END, A DETONATION CHAMBER ASSOCIATED WITH SAID BULLET CHAMBER, A CONTAINER FOR A SUPPLY OF COMBUSTIBLE FLUID, A CONNECTION BETWEEN SAID DETONATION CHAMBER AND SAID CONTAINER INCLUDING A MANUALLY CONTROLLED MEANS FOR RELEASING A DETERMINED AMOUNT OF SAID COMBUSTIBLE FLUID FROM SAID CONTAINER, MEANS FOR MIXING SUCH RELEASED AMOUNT OF COMBUSTIBLE FLUID WITH A FLUID OXYGEN CARRIER TO FORM A CHARGE OF AN EXPLOSIVE GAS MIXTURE AND MEANS FOR DELIVERING SUCH CHARGE TO SAID DETONATION CHAMBER UNDER A PRESSURE GREATER THAN THE ATMOSPHERIC PRESSURE, A RETRACTABLE BREECH-BLOCK LOCATED BEHIND SAID BULLET CHAMBER AND NORMALLY FORMING A WALL OF SAID DETONATION CHAMBER, A TRIGGER MECHANISM, MEANS ACTUATED BY SAID TRIGGER MECHANISM FOR IGNITING SAID CHARGE, AND A SPRING-OPERATED VALVE NORMALLY SEPARATING SAID DETONATION CHAMBER AND SAID BULLET CHAMBER, SAID VALVE BEING BUILT-IN IN SAID BREECH-BLOCK AND FORMING SAID WALL OF THE DETONATION CHAMBER.

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