US2669160A - Belt feed for firearms - Google Patents

Description

Feb. 16, 1954 B'. MAILLARD 2,669,160

` BELT FEED FOR FIREARMS Filed June l5, 1949 2 Sheets-Sheet 1 ATTURNEY a, T L NM NN ww E. Sm .wm w E- 1 EEN/EEE# W WM E my .w @Wf Mw E www w45 5 lf Z Feb. 16, 1954 B. MAILLARD BELT FEED FOR F'IREARMS 2 Sheets-Sheet 2 Filed June 13, 1949 ATTORNEY Patented Feb. 16, 1954 2,669,160r BELT FEED Foa FmEARMs Bernard Maillard, Geneva, Switzerland, assignor to the Society Brevets Aero-Mecaniques, S. A., Geneva, Switzerland, a society of Switzerland Application June 13, 1949, Serial No. 98,736

Claims priority, application Luxembourg Y June 19, 1948 (Cl. Sil- 33) 2 Claims.

The present invention relates to semi-automatic rearrns the reloading of which takes place automatically but with which the gunner must operate the trigger upon every shot, automatic firearms iiring by bursts and arms capable of working either in a semi-automatic or in a fully automatic manner, these firearms including a movable breech piece having a reciprocating motion in a direction substantially parallel tothat of the firing axis of the arm. It is more particularly concerned with arms of this kind supplied with ammunition from a flexible belt on which the cartridges are disposed at regular intervalsl of a value hereinafter called Athe pitch of the belt, said belt being actuatedby a feeding device operated by the movable breechblock of the arm in such manner that the forward movement of the belt taires placev by successive steps equal to fractions of the pitch and in particular to one half thereof. l

According to a feature of my invention, in a firearm provided, for the discontinuous drive of the cartridge belt by a feeding deviceoperated step by step by the movable breechblock so that two successive steps correspond to a total feed displacement of an amplitude equal to the pitch and take place, respectively, the first one during the recoil stroke of said breechblock and the second one at the rend of the frontward return stroke thereof, I arrange 'a Icanfnning mechanism through which said feeding device is operated by the movable breechblock', in suchmann'erthat the'rst step begins only after said breechblo'ck has moved through a substantial portion of its recoil stroke, whereby, in particular, I reduce the path of travel during which the nose ofthe breech piece rubs along the lower generatrix of the cartridge brought along the axis of the arm by the rst step.

Preferred Aembodiments of the present invention will be hereinafter described with reference to the accompanying drawings, given merely by 'way of example and in which:

Figs. l to 4 show, respectively in vertical section, in top View with .parts in section and parts cutaway, and in 'cross sections in two dilerent respective vertical planes, an automatic lirearm made according to the invention; g 1

Figli diagrammatically shows, in four difierentoperating positions, certain parts of the feed device 'included in the'arm lshown* byFigsl to 4;

ylilig'.' Sis a transverse half-section ofafirst construction ofthe device operatedby the movable vbreecliblock fory actuating the feeding Kde-rv Vquerif.:

Figs. 'l` and 8show, respectively in cross section and in longitudinal section on the line VIII-EVIII of Fig. 7, a second construction.

In the following description, it will be supposed that the invention is applied to a machinegun, fed withk cartridges by means of a belt l on which are xed cartridges 2, the forward movement of the belt talcing place in a discontinuous manner, by successivepsteps equal each to one half of the pitch, under theaction; o fa feeding device. ,1, This rearm includesr,v` in`the usual mannena barrel (not shown on the drawings) connected at the rear with a breech casing .3 in whichV moves, against the action 0f ,a @generatorspringing. movable loieechblock aprovidred,. .VatA itsupper; front end, with anose Salcapable of introducing into the barrel cartridge chamber, during the return stroke of the breechblock, the` cartridge brought along the .axis of l:said chamber bythebelt feeding mechanism (feedingfudevice), which is to be more explicitly describedhereinafter.,y

The whole of the barrel and of breech casing 3 is supported by a stock :ty withrespect to which said whole is given a reciprocating motion V(recoil movement and return movement) during the operation of. the firearm. f o Y e, I mount on said stock a cover l, intended to reg-fceive the feedingdevicaianda feed guide 8, the latter supporting the belt'lA andfbeing provided with a gapinfitfs middlepcrtion to permit passage, between two introduction-,edges 8a, ofthe... breechblock nose Eaduring'fthe step of intro1u..v tion of the'cartridge into the arm barrel.

It should be noted here that A co'verl doesvnot participate in the recoil',movementv of breechv casing 3 and that, due tothe fact thatfit is stationary, it is particularly adaptedtoact assupport for the feeding device intendedto `move' beltl.

This feeding device is arranged tojproduce a discontinuousstep by stepmovementof said belt, the movement of 4one cartridge over afdistance equal to the pitch therefore taking place in two steps, to Wit a preparatory step of. an amplitude. equal to one halffpitch, the effect ofwhich is to bring this rcartridge into awaiting position (shown for cartridge 2 in the Diagram ,l of Fig, 5), and a complementary step,Y also `of onehalf? pitch, ensuring the passage of said cartridge` from this waiting position to the introductoryuposi-w tion (shown at 2 on the Diagram of Eig.;5,) 1., K

Y For a predetermined cartridge, the. prepaliatory;r

Sie?. and ille. Gemplemeuiery step above referred..

(backward and forward strokes of breechblock 5), every full reciprocation of said breechblock producing first the complementary step relative to the cartridge which is in waiting position and the introduction of this cartridge into the cartridge chamber and, then, the preparatory step relative to the next cartridge which is thus brought into waiting position.

The cycle of operation of the feeding device having thus been defined in a general manner, according to the main feature of my invention, said device is controlled by breechblock 5 in such manner that the complementary step of a cartridge in waiting position takes place during the breech recoil stroke and begins only after said breechblock has travelled through a Vsubstantial portion of this recoil stroke.

In this way, and contrary to what took place with the already known feeding device of the same kind, for which the complementary step took place immediately upon the beginning of the breechblock recoil stroke, I avoid rubbing of the nose 5a of said breechblock over the whole length of the lower generatrix of the cartridge fed into position of introduction, between the edges 8a of passageway 8, by said supplementary step.

In particular, if cartridge 2 is brought into introductory position only after the nose 5a of the breechblock has moved past the rear of the neck 2c, of the cartridge case, any risk of deteriorating this relatively weak portion of said cartridge case is avoided.

For instance, in the case of cartridges of the usual type, the beginning of the complementary step may correspond to breechblock 5 having already moved a distance equal to two thirds of its recoil stroke.

It seems particularly advantageous to make the feeding device according to the embodiment illustrated by the drawings.

Such a device includes two sliding members 9 and I0 carried by cover 1 and capable of moving transversely with respect to the axis of the rearm, these sliding members being tted with respective pawls I I and I2, said pawls being each retracted against the action of a spring (not shown) when the corresponding sliding member moves in a direction opposed to the direction of feed of belt I and coming on the contrary to catch a cartridge and to drive said belt over a distance corresponding to one half of the pitch when said sliding member is moved in the direction of forward feed of the belt.

Sliding members 9 and I0 are controlled by an oscillating lever I3 hinged aboutia pivot axis I4 on cover 1, and connected to said sliding members in such manner that they move in opposite direcof a roller 20 carried by said lever I3 and movtions to each other, for which purpose, for instance, sliding member I0 is directly acted upon by the front end of lever I3 and there is interposed between said end and sliding member 9 a link I5 pivotally mounted on cover 1 about an axis I6 located substantially opposite the middle point of said link.

Oscillating lever I3 is driven by movable breechblock 5 by means of a camming mechanism including a cam I1 pivoted (about axis I8) to breech casing 3 and subjected to the action of a return spring I9 intended to keep said cam in correct position when said cover is closed. Connection between cam I1 and lever I3 takes place through a device adapted to permit recoil movement of breechblock casing 3 with respect to cover 1, for instance through the intermediate ing between guides 2| rigid with cam I1.

A cam follower constituted by a roller 22 is mounted on breechblock 5` opposite cam I1, the active portions of said cam being., arranged in such fashion that, on the one hand, the complementary step of a cartridge in waiting position takes place after the breechblock has moved a distance corresponding to a substantial portion of its recoil stroke (active portion |10.) and, on the other hand, the preparatory step corresponding to the next cartridge takes place at the end of frontward return of said breechblock (active portion I1b).

The whole of the active portions I1a (corresponding to the end of the recoil stroke of the breechblock) and I1b (corresponding to the second fraction of its return stroke) therefore has a characteristic curve with a double concavity which is shownby a reinforced line on the diagrams of Fig. 5, points ra and rb of this curve (which might possibly coincide together) corresponding respectively to the beginning of the intervention of active portion I1a during the recoil stroke of movable breechblock 5 and of active portion I1@ during the return stroke of said movable breechblock.

I will now indicate in a more detailed manner and with reference to the diagrams of Fig. 5, the various phases of operation of the feeding device above described.

Considering the iirearm just when a cartridge previously introduced into the cartridge chamber is fired (Diagram I, the next cartridge 2 is in waiting position and roller 22 in contact with the front end of the active portion I1b of cam I 1. During the first fraction of the recoil stroke of the breechblock and up to the time when roller 22 moves past point ra, the position of cam I1 remains unchanged since said roller remains practically away from said active portion I1b; the nose 5a of the breechblock therefore moves freely toward the rear between the edges 8a, of passageway 8. On the contrary, from this time on, roller 22 attacks the active portion I1 and causes cam I1 to swing (positions at the beginning of this attack and position at the end of the recoil stroke represented respectively by Diagrams II and III). This phase corresponds to the complementary step which brings cartridge 2 between the edges 8a, i. e. across the path of travel of the nose 8a of the breechblock; during the first portion of the return stroke of the breechblock 5, cartridge 2 is extracted from the belt which is stationary and is introduced into the cartridge chamber; when roller 22 moves past point 1t and only from this time on, the active portion I1b is acted upon and cam I1 is returned (position shown by Diagram IV) into the position it occupied initially (Diagram I), this phase of the operation corresponding to the preparatory step for the next cartridge, which cartridge is then brought into waiting position at a distance from the ring axis equal to one half of the pitch. The various elements of the arm are then back into their initial position and the cycle is repeated upon the next recoil stroke of the breechblock.

With such an arrangement, the recoil movement of the breechblock is braked only for a. relatively short time, due to the fact that the cartridge is brought relatively late into introductory position.

Furthermore, as already stated, this arrangecidental cause, said breechblock has moved backward to a distance non negligible but however insuilcient for catching the cartridge, in which case, for an arm tted with a feeding device of a conventional type which starts bringing the cartridge into position of introduction as soon as the recoil stroke begins, wedging of the arm would be unavoidable.

Advantageously, at least a portion of breechblock 5 is protected against the transverse reaction, produced for instance by the action of roller 22 against cam Il, by fitting this breechblock with at least one bearing piece, such for instance, as a roller 23, cooperating in the transverse direction with a bearing surface, such for instance, as a rectilinear rail 24 rigid with the breech casing 3.

Preferably, roller 23 is so located as to absorb the perturbing reaction in the very region where it originates, whereby I avoid any tilting torque which might produce wedging of the breechblock.

For this purpose, I may for instance, as shown by Figs. 1 to 3, mount roller 23 coaxially with roller 22 Iand immediately below (or above) it.

I may also, as shown by Fig. 6, provide two rollers 23 located coaxially with roller 22, respectively above and below said roller, in which case the perturbing torque is wholly eliminated.

According to a modification which also permits of eliminating the perturbing torque, I place rollers 22 and 23 side by side (in the transverse direction) as shown by Figs. '7 and 8.

In a general manner, while I have, in the above description, disclosed what I deem to be practical and efficient embodiments of my invention, it should be well understood that I do not Wish to be limited thereto as there 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 claims.

What I claim is:

1. A rearm of the type described in which the cartridges are detachably carried by a belt and juxtaposed along said belt transversely thereto at a constant interval or pitch from one another, which firearm comprises, in combination, a stock, means forming a cartridge chamber movable with respect to said stock in a direction parallel to the axis of said chamber, a cover rigid with said stock, a breech casing rigid with said chamber, a breechblock movable in said breech casing with a reciprocating motion parallel to the axis of said cartridge chamber and including a recoil stroke and a return stroke, means carried by said breechblock for pushing into said cartridge chamber, during the return stroke of said breechblock, a cartridge located in a lgiven position parallel to said axis, a feeding device for moving said belt transversely to said axis with a step by step displacement of an amplitude equal for every step to one half of said pitch, alever pivoted to said cover and operatively connected with said feeding mechanism for operation .thereof, a cam pivoted to said breech casing operatively connected with said lever, and a roller carried by said breechblock in cooperating contact with said cam for actuating it, said cam being shaped to cause every step of the displacement of said belt that brings one cartridge into said given position to occur only after said breechblock has moved through a substantial part of its recoil stroke and to cause the next step of this belt displacement to take place at the end of the next return stroke of said breechblock.

2. A firearm of the type described in which the cartridges are detachably carried by a belt and juxtaposed along said belt transversely thereto at a constant interval or pitch from one another, which firearm comprises, a combination, a stock, means forming a cartridge chamber movable with respect to said stock in a direction parallel to the axis of said chamber, a cover rigid with said stock, a breech casing rigid with said chamber, a breech block movable in said breech casing with a reciprocating motion parallel to the axis of said cartridge chamber and including a recoil stroke and a return stroke, means carried by said breech block for pushing into said cartridge chamber, during the return stroke of said breech block, a cartridge located in a given position parallel to said axis, a feeding device for moving said belt transversely to said axis with a step by step displacement of an amplitude equal for one step to a portion of said pitch and for the next step to another portion of said pitch such that the sum of these two portions is equal to said pitch, a lever pivoted to said cover and operatively connected with said feeding mechanisrn for operation thereof, a cam operatively connected with said lever and pivoted intermediate its ends to one of the breech mechanism elements constituted by said breech casing and said breech block respectively, a cam follower carried by the other of said elements to travel in a substantially straight path, said cam having cam surfaces on each side of said pivot and shaped to be engaged by said cam follower at areas spaced from the pivot to actuate the cam to cause every step of the displacement of said belt that brings one cartridge into said given position to occur only after said breech block has moved through a substantial part of its recoil stroke and to cause the next step of this belt displacement to take place at the end of the next return stroke of said breech block.

BERNARD MAILLARD.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 863,101 Schwarzlose Aug. 13, 1907 2,417,080 Lochhead Mar. 11, 1947 FOREIGN PATENTS Number Country Date 700,629 Germany Dec. 24, 1940 OTHER REFERENCES Einzelausbildung AM M. G. 42 (Technical Manual for German Machine Gun 42, 29 pgs., March 15, 1943 (On file in Division 70.)

Images