Absorbing means especially for firearms

Nov. 7, 1944.

M. BIRKIGT

2,361,985

ABSORBING MEANS ESPECIALLY FOR FIREARMS

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Patented Nov. 7,1944

2,361,985

UNITED STATES PATENT OFFICE

2,361,985

ABSORBING MEANS ESPECIALLY FOR FIREARMS

Marc Birkigt, Versoix, near Geneva, Switzerland

Application April 24,1940, Serial No. 331,472

In France October 14,1939

Claim. (Cl. 42—3)

The present Invention relates to means for preventing or at least partly absorbing injurious reboundings of systems which are to be stopped, at least temporarily, by abutment against a fixed element. The invention is more especially, al- _sthough not exclusively, concerned, among these means, with those intended to prevent dangerous rebounding of parts or combinations of parts adapted to keep temporarily in active position a system for ensuring the locking of the breech ιθ system of an automatic firearm.

The object of the present invention is to provide means of the type above mentioned which are better adapted to meet the requirements of practice than those used for the same purpose up ₁₃to the present time.

According to an essential feature of the present invention, I provide, in the system which is to be protected against rebounding, at least one chamber or recess in which is mounted a sliding mass 20 adapted to undergo, under the effect of inertia and against the action of an elastic device, when the system is stopped by abutment, a displacement at the end of which there is produced a shock against the front end of its chamber, said 25 mass being preferably chosen in such manner that its momentum substantially balances the rebounding energy of the system when the shock in question takes place.

Other features of the present invention will ₃₀result from the following detailed description of some specific embodiments thereof.

A preferred embodiment of the present invention will be hereinafter described, with reference to the accompanying drawing, given merely by ₃₅way of example, and in which:

Fig. 1 is an elevational view of the breech mechanism of an automatic gun made according to the present invention, with a device for preventing the rebounding of certain parts; ₄₀

Fig. 2 is a transverse sectional view on the line II—II of Fig. 1;

Fig. 3 is a horizontal sectional view on the line ΙΠ—ΠΙ of Fig. 1;

Fig. 4 is an elevational view similar to Fig. 1, 45 showing the breech mechanism in the locked position.

In the following description, I will consider the case of an automatic gun in which the breech system is locked in the firing position thereof. ⁵⁰The object of the invention is to provide a device for preventing the detrimental rebounding of the parts which temporarily maintain the breech system locked in active position.

Preferably, the firearm is devised in such man- 55 ner that, when the breech system is locked, a rigid whole, including a firing pin or the like and safety inclined surfaces, keeps moving toward the front, under the effect of a return spring and by inertia and thus fires the cartridge, the safety eo inclined surfaces positively compelling, during the whole period of time for which they are in frontward position with respect to the breech block, the locking means to remain in active position.

According to the essential feature of the present invention, I provide in the combination including the means for ensuring the temporary fixation of the locking means in the active position (that is to say the rigid whole above mentioned including the safety inclined surfaces in the case of the automatic firearm above considered) at least one chamber or recess, L in which is mounted a sliding mass M adapted to undergo, by inertia and against the action of elastic means S, as soon as said whole comes to abut, at the end of its stroke, against a fixed part of the arm, a displacement producing a shock against the front end of chamber L.

In such an arrangement, if, for some reason the cartridge is not fired immediately the firing pin assembly has reached the end of its stroke, that is, when a misfire (sometimes called a hangfire) occurs, this assembly rebounds.

But, before the recoil movement of the firing pin assembly has reached the amplitude for which the safety inclined surfaces cease to act, mass M comes to produce, against the front end of its chamber, a shock in the course of which it imparts to said assembly its own momentum which is in a direction opposed to the rebounding force of the firing pin assembly.

Preferably, in this case, the relative masses of said system and of element M will be chosen in such manner that the momentum of said element, when the shock takes place, substantially balances the perturbing rebounding energy.

In this way, the shook of mass M against the front end of its chamber stops the recoil movement of the firing pin assembly and, accordingly, this movement is limited to a small amplitude, for which the safety Inclined surfaces are still in a position to maintain the breech system locking device in active position.

I will now proceed to describe more in detail the particular embodiment illustrated by the drawing.

At the rear of barrel i, which is made of any suitable structure, I fix a breech box 2 inside which a breech block can move with a reciprocating movement.

This breech box 2 includes the following elements:

a. On the one hand, a slot 3 for the feed of cartridges; and

b. On the other hand, an aperture 4, which may be diametrally opposed to said slot, for the outlet of the empty shells of the spent cartridges.

I provide, for reciprocating movement in said box 2, a breech block 8.

The breech block 6 carries a firing pin as2'

2,301,985 sembly which includes two slide members 9 disposed on opposite sides of the breech block 6 and connected, preferably at the front, by a cross piece 10 acting as a support for the firing pin 11. The firing pin assembly may reciprocate in the breech box 2, together with the breech block 6, and it is also mounted for relative reciprocating sliding movement with respect to the breech block 6. A spring S, acting on the firing pin assembly urges the breech block 6 toward its closing position in which the breech block has pushed the cartridge into the gun chamber and into position for firing.

I provide the breech block 6 with locking means 7 according to produce the following results, according as said device or means is in the upper or lower position:

a. Either to secure, as long as breech block 6 is behind its firing position, said breech block to the firing pin assembly, by bearing against an inclined surface 8 carried by said firing pin assembly;

b. Or, on the contrary, to lock breech block 6 with respect to breech box 2 once said breech block has reached its firing position, in which case, the firing pin assembly is free to move forward a further distance, owing to the provision of an elongated passage 6' in the breech block 6 for a transverse member 10 (above mentioned), under the action of recoil spring 5 which bears against said transverse member. The cartridge being held in position by breech block 6, can thus be fired by the firing pin I i. In this position, the safety inclined surfaces above referred to are the rear edges 9 of slide members 9 for keeping the locking means 7 in the lower position (shown by Fig. 4).

I provide means, such for instance as the combination of a cylinder 12 and a piston 13, the movable part of which is rigid With a push piece 14, for ensuring, owing to the pressure supplied by a portion of the burnt gases, the recoil movement of slide members 9 until the rear edges 9” thereof cease to act on the locking means 7 and said slide members come to abut against breech block 6 which is then disengaged from breech box 2, owing to the reversibility of inclined sinface 15 on which the locking means 7 is bearing, said breech block being then pushed rearwardly together with the slide members 9 to which it is then secured through the locking means 7,

Advantageously, I interpose between the breech block 6, and the firing pin assembly, an elastic system which tends to push the firing pin assembly toward the front part of the breech block 6, the breech block 6 being supposed to be fixed at this time.

For this purpose, I provide in the slide members 9 recesses 9' in which abutments 16 rigid with breech block 6 are movable when relative movements take place between the slide members 9 and breech 6.

I fit, in these recesses, springs 17 which bear, through their front ends, against rods 9, and through their rear ends against the corresponding abutments 16. These springs tends to oppose constantly the recoil of said slide members 9 with respect to breech blocks 6.

According to a particular embodiment of the invention, I provide respectively in each of the slide members 9 two chambers or recesses L in which are mounted masses M the sliding displacements of which are guided by pistons p which, engage in holes provided for this purpose in said masses. Springs S are provided on the inside of said holes so as to urge the masses rearwardly (toward the positions of rest illus₅ trated by Figs. 1 and 3).

The strength of these springs will then be chosen in such manner that the masses come to strike the front ends of their chambers when the slide members come to be stopped (position 10 shown by Fig. 4) and that, at the time of the shock, their momentum is sufficient for ensuring the balancing of the rebounding energy.

It should be noted that safety springs 17 also oppose, to a certain degree, a detrimental re13 bounding of the slide members, but their action is purely of a static nature, and they serve rather to prevent any undesirable backward movement of said slide members under the action of gravity for instance when the gun is vertical, or in case 2o of breaking of the return spring.

The operation of the device according to the invention results sufficiently clearly from the above description for making it unnecessary to enter into further explanations.

₂₅ In a general manner, while I have, in the above description, disclosed what I deem to be practical and efficient embodiments of the present invention, it should be well understood that I do not wish to be limited thereto as there ₃₀ might be changes made in the arrangement, disposition and form of the parts without departing from the principle of the present invention as comprehended within the scope of the accompanying claim.