US2471232A - Firing mechanism for automatic guns having transversely movable breech blocks - Google Patents

Description

May 24, 1949. D. w. MOLINS 2,471,232

FIRING MECHANISM FOR AUTOMATIC GUNS HAVING TRANSVERSELY MOVABLE BREECH BLOCKS 3 Sheets-Sheet 1 Filed July 20, 1943 3 Sheets-Sheet 2 Filed July 20, 1945 m N H w y 1949- D w MOLINS 2,471,232

FIRING MECHANISM FOII AUTOMATIC GUNS HAVING TRANSVERSELY MOVABLE BREECH BLOCKS Filed July 20, 1943 3 Sheets-Sheet 3 If; F

- 2 y f 5% a 14 fl lfZZZI' 5 z 4 2a ?mmumuuma F 6y 4, 1,4111. 4/415, flTTOK VE) Patented May 24, 1949 FIRING MECHANISM FOR AUTOMATIC GUNS HAVING TRANSVERSELY MOVABLE BREECH BLOCKS Desmond Walter Molins, London, England, as-

signor to Molins Machine Company, Limited, Deptford, London, England Application July 20, 1943, Serial No. 495,522 In Great Britain June 25, 1942 14 Claims.

This invention concerns improvements in or relatin to ordnance of the kind havin a sliding breech block which moves transversely of the barrel axis and which uses fixed ammunition, that is to say in which the projectile and charge are assembled as a single unit. Where the term round is used herein it shall means such ammunition. For convenience the term ordnance will be replaced hereinafter by a gun.

A gun of this kind may be provided with automatic feeding, ramming and firing devices, and may then be termed an automatic gun and for brevity will be hereafter referred to as an automatic gun of the kind described.

An object of the present invention is the provision of an improved device whereby the existing firing mechanism of a non-automatic gun with a transversely sliding breech and using fixed ammunition may be automatically operated so that on the addition of automatic feeding and ramming devices said gun becomes an automatic gun of the kind described. i

In guns of this kind the breech block is provided with a spring-pressed firing pin and it is important that the firing pin shall not be operated until the breech is fully closed and the firing pin is centralized with the cap of the cartridge. If the firing pin is prematurely released it may not strike the cap and a misfire will occur. The firing pin is cooked by the movement of a cocking member in the breech block and to prevent misfires the pin should not be released by the firecontrol mechanism provided in accordance with the invention, that is the mechanism which is first operated to cause the gun to fire, until the said member has moved back again.

In order therefore to ensure the correct functioning of the firing pin the present invention comprises a lever pivoted on the breech ring and having a part adapted to engage said cocking member so that the lever cannot move until the cocking member has moved back to be free of the firing pin. The lever is connected to firecontrol mechanism which is actuated to initiate the firing of the gun but it will be seen that even though this mechanism is actuated the gun will not fire unless the cocking member is in its proper position. Thus under all circumstances the earliest instant of firing is determined b the position of said cocking member. Another device described later may effect still further control of the firing instant but it cannot occur before the cooking member is in the correct position.

In some guns, for example the one hereafter described with reference to the drawings, the

existing arrangements are of such nature that the addition of automatic firing mechanism causes a certain amount of lateral pressure to be exerted on the breech-block which makes it sluggish in closing and to over-come this the abovementioned lever may be constructed as a multiplying lever whereby this pressure is reduced in the ratio of the lever arms.

Two examples of an automatic gun of the kind described embodying the invention will be described by way of example with reference to the accompanying drawings which show parts of the breech and firing mechanism of a six-pounder gun.

In the drawings:

Figure 1 is a front elevation of the .breech showing the sliding breech block, breech operating devices and firing mechanism.

Figure 2 is a sectional elevation of Figure 1.

Figure 3 is a side elevation of Figure 1 taken in the direction of the arrow A, some parts being omitted.

Figure 4 is a plan view of Figure 3 partly broken away.

Figure 5 is a perspective view of the breech showing a modified form of the invention, and the figure also serves to show the general construction of the breech and associated parts in suchagun.

Figure 6 is a fragmentary section of Fig. 1 on the line 66.

For convenience, known parts of the breech and firing mechanism bear alphabetical references while parts necessary for modifying the known mechanism in accordance with the invention have reference numerals.

In this gun the barrel is slidably mounted on a cradle which is provided with trunnions which are journalled in bearings on the gun mounting and a recoil spring is provided for urging the barrel forwardly on the cradle.

Referring first to Figures 1, 2 and 5 of the drawings, the breech ring a is provided, with a transversely sliding breech block b which is adapted to close automatically on the insertion of a round and the firing of the round is arranged to take place by depressing a firing trigger or like device on the breech block as will be explained in more detail later. The breech block is opened manually by means of a hand lever c, Figure 1, fixed to a cross-shaft d on which is also mounted an opening lever e, Figure 2, and it will be seen by comparing Figures 1 and 2 that when the handle 0 is moved anti-clockwise around the axis of the shaft 01, (as viewed in Figure 2) the lever 3 e provided with a pin e in a slot g in a sliding block 9 will cause the breech block to move downwards. It will also be seen that before the pin e' reaches the lower end of the slot g and starts to move the, breech block down, the lever e through the, pin 6' pushes the sliding block or cocking member 9 (technically known as the link) which forms part of the cocking mechanism, as explained later to the left in Figure 2. As the breech opens the link g first moves rearwardly to withdraw the strilring pin is from the base of the round and only moves to its forward position after the breech is closed in order to permit the gun to fire. During the operation of the hand lever c, a sprin not shown, but con.- tained within a spring-barrel h, Figure l, is compressed by means of a rack and pinion device associated with said hand lever, and the breech is held open by suitable catches on the extractors against the action of ill: spring. When a round isrammed home and stilkes the extractors of the gun, the catches are released and the breech block snaps up under the influence of the spring in the barrel h to close the breech, all this mechanism being of known construction, as exemplified by. British Patent No. 579,984.

When the gun is fired it recoils and then runs out, and towards the end of the run-out the breech is automatically opened by means of a roller 2', Figure l, which runs up a cam not shown in Figures 1 and 2, but which is like the cam 7' shown in Figure 5, and it will be apparent from Figures 1. and 2 that the movements of the roller 2 will operate the shafe d and cause the lever e to open the breech against the action of the previously. mentioned spring. As the breech is automatically opened, the spent cartridge case is extracted and the breech is thereafter held open by the extractors until the next round is rammed and the extractors are carried forward by the flange at the base of the round, whereupon the breech closes. The firing pin 7a, Figure 2, is cocked by the action of opening the breech as the link 9 causes the firing pin to be retracted against the action of th spring m, but as usual the firing pin has to be moved clear of the percussion cap, in the spent cartridge case before the breech opening movement commences. Conversely, as the breech closes, the cooking device does not move entirely clear of the firing pin until the breech has properly closed, the lever e moving a slight amount after complete closure of the breech so as to return the cocking member or link 9 to the position shown in Figure 2 and. thereby permit unobstructed movement of the firing pin it.

In the non-automatic gun the firing is efiected by pressing a firing trigger w on the breech block through the medium of a firing lever n pivoted at to the breech ring and having at its upper end a portion a disposed at right angles to the main arm of the lever. The lever is controlled or steadied by means of a plate p fixed to the breech ring. It will be seen from Figure 1 that as the movement of the firing lever is small and the radius of oscillation is considerable the upper part 2 of the lever moves substantially at right angles to the movement of the breech block. A spring pressed rod 11 attached to the upper part of the lever engages a fixed abutment 7", Figure 1, onvthe breech ring, the parts being so disposed that the spring tends to urge the top a of the firingl lever away from the axis of the gun barrel. Tocause the gun to fire in known constructions, the. lever n. is pushed inwards towards the barrel 4 axis by a hand operated lever similar to the lever s in Figure 5 and mounted on the cradle so that the operative end of the hand operated lever, or a part coupled thereto, is in alignment with the part a of the firing lever. only when the run-out is complete.

In adapting this known firing mechanism for use in the automatic gun, the hand lever is, in the constructions shown in Figures 1, 3 and 4, disconnected from operative engagement with the firing lever and the necessary pressure on the firing lever is obtained from a spring operated fire-control-device' the spring of which is loaded by the barrel movement on the run-out.

Referring now to Figures 1, 3, 4 and 6 of the drawings, this fire-control-device comprises a spring pressed plunger i mounted in a tube or barrel 2 which is screwed into a boss 3 of a bracket 4 attached to a member i, see also Figure 5, which is in turn fixed to the cradle of the gun. A compression spring 5 inside the barrel urges the plunger end outwardly from the tube 2, that is in a direction towards the rear of the gun. The spring pressure may be adjusted by screwing the tube 2 in or out of the boss 3 after which the parts are fixed by a clamp 55 which surrounds an extension 1 0f the boss 3 which extension is split so that it may be contracted by the clamp.

A bellcrank lever 60, I2 is pivotally mounted at 8 on a bracket 9 fixed on the breech ring a. One arm ill of the bellcrank lever is provided with a roller i! which is in operative engagement with the spring plunger i when the run-out is completed and. the free end of the other arm i2 of the bellcrank is provided with a roller l3 which engages a further roller I i mounted on a pin [5 fixed to the upper part a of the firing lever n;

As the roller 5 i on the short arm of the bellcrank' lever strikes against the end of the spring plunger 5 at the end of the run-out, it presses in or spring loads the plunger 5 while the roller IS on the long arm of the bellcrank lever presses hard against the roller i4. As aforesaid, the breech is open at the end of the run-out and remains open until the next round is rammed and while it is open an abutment u, Figure l, on the firing lever engages the side of the breech block so that the firing lever cannot be moved in until the breech block closes. When the breech block is properly closed a recess 1) in the side of the breech block registers with the abutment u as seen in Figure 1, thus enabling the part .2 of the firing lever to be moved inwards.

As aforesaid it is important to ensure that the firing pin is centralized with the cartridge cap and this means that the breech block must be completely closed. To prevent the pin from operating until this is so the control of the firing instant is determined by the cocking member g which cannot move inwards until after the breech block has closed and this member controls the spring operated fire-control-device above described through a lever i6 described below which engages the cooking member and forms therewith a catch device.

As considerable pressure is required to cause prompt operation of the firing trigger and associated mechanism in the gun illustrated, it will be seen that the abutment u would exert a heavy pressure (derived in the present example from the spring loaded plunger I) laterally on the breech block and this pressure is sufficient to hinder the closing of the breech or at least to make it sluggish and impair the rapid automatic operation of the gun.

To overcome this drawback the lever of the catch device is constructed as a multiplying lever I6 pivoted at I I on the breech ring a and connected to the upper part of the firing lever as described below and so arranged that the side of the lower part of the multiplying lever adjacent the free end thereof contacts the side of a block 21 attached to the link g which is mounted on the breech block and is, of course, in the rearward position when the breech block is opened by the movement of the lever e as previously described. As it is the end of the lever It which presses on the block 21, the full force exerted by the spring closing plunger near the fulcrum of this lever cannot be applied by the remote end of the lever. Owing to their respective positions, the tail of the lever I6 exerts less pressure on the block 2! than can the abutment u on the breech block. On the lever 8 there is mounted an eccentrically adjustable pivot I8 to which is attached one end of a connecting link til, the other end of this link being connected to the pin I5 previously mentioned which is fixed to the upper part c of the firing lever n. The distance between the pivots I l and 18, Figure 1. therefore forms one arm of the multiplying lever while the distance from the pivot I! to the free end of the lever where it contacts with the block 21 forms the other arm, the ratio between the arms being about 1:4 at the minimum. It will be seen that by turning the eccentric pin I8, slight adjustment in the position of the lever It may be made since in this way the effective length of the link I9 can be varied. The spring pressed rod q on the upper part a of the firing lever tends to move the free end of the lever I6 away from the block 21 and further into a groove or housing 20 formed in a member 2| attached to, or integral with, the steady plate p which is fixed to the breech ring. But when the plunger I is operative to apply pressure on the part 2, the force of the spring pressed rod q is overcome and the multiplying lever is pressed against the block 27.

When the gun is fired and recoil takes place, the bellcrank lever III-I2 being attached to the breech ring travels with the recoiling parts and as it is now free from engagement with the spring plunger I it is free to move on its pivot 8 and so the spring pressed rod q on the upper arm of the firing lever pushes the upper part a of the firing lever outwards from the axis of the barrel and thus the multiplying lever I6 is moved about its pivot I? so that its free end moves further into the groove 20 and clear of the block 2'! on the link g. At the same time the bellcrank lever Iii-I2 is turned on its pivot 8 by the pressure of the firing lever so that the short arm If! of the bellcrank lever comes into alignment with the spring plunger I and will strike it later on towards the end of the run-out.

As the gun barrel completes the run-out after the firing of a round, the breech opens. As at this time the block 21 attached to the link g is in its rearward position relative to the breech block b, the part a of the firing lever is pressed outwards by the engagement of the abutment u with the side of the breech block so that the roller It engages against the roller I3 and forces the arm I2 of the bellcrank lever outwards so that the bellcrank lever moves on its pivot 8 and the roller II on the short arm engages the spring plunger and compresses the spring 5. This causes the spring plunger I to be cooked. While compressing the spring, the bellcrank lever has also started to force the firing lever inwards, but this inward movement is limited by the free end of the multiplying lever I6 havin moved a further distance towards the block and engaged the side of the block 21 on the link g thus taking the pressure due to the spring plunger I and preventing the abutment u on the firing lever from pressing against the side of the breech block. The lever I6 can only move in to allow firing to occur when the block 21 on the link 9 has moved to its forward position.

As the next round is rammed the breech block snaps into the closed position under the action of the spring in the barrel h and the link 9 moves inwards. As aforesaid the link is moved outwards by the lever e and this lever also serves to move the link g inwards. The lever is, as previously stated, operatively connected to the link by the pin e, Figure 2, which works in a slot g formed in the link. The slot is of sufficient length to enable the breech block to close just before the link reaches its final inner position and so shaped that on the breech opening movement the link begins to move outwards just before the breech block begins to move downwards to move the firing pin free of the spent percussion cap as previously explained. The movement of the link frees the end of the multi plying lever I6 from the block 21 which movement in turn allows the upper part of the firing lever to move inwards since the abutment u at this time is opposite the recess 22 in the breech block. Thus the upper arm of the firing lever i now forced inwards under the pressure of the spring plunger I and the movement is transmitted to the firing trigger 10 so that the gun is fired. Therefore, by this arrangement every time a round is rammed it is automatically fired. The operative end of the block 21 i. e. where it is engaged by the lever I6 is made sharp as shown at 28, Figure 6 to facilitate fine setting and the block is fixed to the link 0 by a screw 28, an adjustable screw 58 threaded in the block 27 being also provided to enable the edge 28 to be set exactly as required by pressing on the link 9, see Fig. 6.

A further catch, called for convenience the firing release catch, is provided to enable the spring plunger I to be held in the compressed position, i. e. cocked, irrespective of the tripping of the end of the multiplying lever by the breech block movement, and when this catch is released, firing will take place until the catch is once more moved to constrain the spring plunger. The firing release catch device comprises a bellcrank lever 22 provided with a spring 23 which tends to urge the operative end of the lever into alignment with an extension 24 on the short arm II) of the bellcrank lever Ill-I2. The bellcrank lever 22 is pivoted at 25 on the bracket 4. When the bellcrank lever 22 occupies the position shown in Figure 3 under the influence of spring 23, with its operative end in engagement with the extension 24, the plunger I is releasably latched in fire-withholding position by the pressure of the spring 5. The lever 22 may have attached thereto any suitable operating device such as a handle 26 as shown in chain lines in Figure 3 to which a lanyard may be attached, or a remote control device such as a Bowden cable may be provided to enable the position of the firing release catch to be controlled from a distance so that when the cable is pulled the bellcrank moves on its pivot triggeroperated.

zgevrgzsa- The construction. shown in Figure: 5' isan alternative arrangement for controlling automatic. firing of the gun; that is, the gun fires automatically. as long as the lever S, which constitutes the fire-control-device, is held in the operative position, and thus also single shots may befiredby suitably manipulating the lever.

The fire-control-device comprises a lever S connected'by a link tt'to-a double-armed lever 3| pivoted: at 32 to a. bracket 33 rather similar to the bracket 4 previously described and mounted int-the same way. I he upper end of the lever 3 His arranged to press against a roller 34 on one arm of a bellcrank lever 35 pivoted on the breech ring andwhich has another roller 36 on its other arm. This engages with the roller Hi, and the remaining parts are of the same construction as before.

If the hand=lever Sis pulled in the direction of" the arrow the gun fires and firing will continue'automatically as long as the handle is urged in this direction, a slight jolt being given to it on each run-out as the roller 34 strikes the lever 3i.

In boththe constructions described, the fireoontrol-device can be actuated (in the first case by springpressure by withdrawing the firing release catch, and in the second case by manipulatingthe lever S), before the breech block closes, and the arrangement is such that whilst the firecontrol-device is prevented from operating the :3'

firing trigger until the breech is closed and the cocking member has moved inwards, it operates the trigger automatically Where the latter movement is: completed. Further in both arrangements only a fraction of the force exerted by the fire-control device when so actuated is transferred to the breech block during its closing.

What I' claim as my invention and desire to secure by Letters Patent is:

1'. In firing mechanism for automatic guns of the kind described having a breech block and a breech ring, a cocking member movable into and out of firing position as the breech block is closedand opened, a fire-control-device, a firing member on the block constructed and arranged to be operated by said fire-control-device, a second firing member on the breech ring through which said first firing member is operated, and a catch device arranged to prevent said fire--control-device and said second member from operating said first firing member until said cocking member has moved into firing position and the breech block is closed comprising a lever pivoted at one end to the breech ring and connected by a link to said second firing member, the free end of said lever being arranged to engage said cocking member until said cocking member has moved into firing position.

2. In a gun of the kind described having a barrel arranged to recoil relatively to a support, and having a: breech ring and a breech block, a cocking member, firing mechanism comprising a movable firing member pivoted on the breech ring, a. trigger engaged and actuated by said firing member-when thebreech is closed, means forcing said -fi'ring member against said trigger, and a lever pivoted on the breech ring and operatively connected to said firing member and engaging said cocking member whereby trigger actuating movement: of said firing member is prevented until the breech block is in closed position.

3, III. a gun of the kind described having a barrel arranged torecoil relatively to a support, and having. a. breech ring and a breech block, a cooking member, firing mechanism comprising a movablefiring member pivoted on the" breech ring, a trigger engaged and actuated by said firing member when the breech is closed; a man'- ually operated fire-control-device to force said firing member against said trigger, and a lever pivoted on the breech ring and operatively conneoted to said firing member and engaging said cocking member whereby trigger actuating movement of said'firing member is prevented until thebreech block and said cocking member are ina predetermined position.

4. In a gun of the kind described having a-barrel arranged to recoil relatively to a support, andv having a breech ring and a breech block, a cooking member, firing mechanism comprising amovable firing member pivoted on the breech ring; arigger engaged and actuated bysaid firing membar when the breech is closed, a spring operated fire-control-device loaded by counterrecoil of the gun to force said firing-member against said'trigger to engage and actuate said trigger, anda lever pivoted'on the breech ringand operatively' connected to said firing member and engaging said cocking member to prevent trigger actuating movement of said firing member until the breech block is closed andsaid cocking member is in a predetermined position.

5'. Firing mechanism for automatic guns of the kinddesoribed having a breech block and a breech ring, said mechanism comprising a cooking member movable into and out of firing position as the breech block is closed'and opened, a firecontrol-device, a firing member mounted on the breech block and operated by said fire-controldevice, a second firing member mounted on the breech ring through which said first firing memher is operated by said fire-control-device, meanspreventing actuation of said second firing'member' by said fire-control-device until said cocking member has moved into firing position and inoperative thereafter, comprising a-lever pivoted at one end to-the breech ring and engaging said"- cocking member at. the other end until-said cocking member is in firing position, and a link connecting said lever to said second firing member and a firing release catch engaging said fire-comtrol-device to render said fire-control-device inoperative after said preventing means become inoperative to prevent firing of the gun until saidfiring release catch is disengaged from said firecontrol-device.

6. Firing mechanism for automatic guns of the kind described having a breech block and" a breech ring, said mechanism comprising a cooking; member movable into'and out of firing position as the breech block is closed and opened, a spring; operated fire-control-device, a firing member mounted on the breech block operated bysaid" fire-control-device, a second firing member mountedon the breech ring-through which said first firing member is operated by said fire-control-device and means preventing said fire-control-device from actuating said second firing member until said" cocking memberis in firingposition and inoperative thereafter, comprising a lever pivoted at one end to the breech ring, alink connecting said lever to said second firing mem her, the free end of said lever engaging saidcockingrnember'until said cocking member is in firing position.

7'. Firing mechanism for automatic guns' ofthe-kind described having a breech block and" abreec'n ring, said mechanism comprising a cocking member moved into firing'positionwhen the breech block'is closed; a manuallyoperated firecontrol-device, a firing member mounted on the breech block, a second firing member mounted on the breech ring through which said first firing member is operated by said fire-control-device, and means preventing actuation of said second firing member by said fire-control-device until said cocking member has moved into firing position and inoperative thereafter comprising a lever pivoted at one end to the breech ring and connected by a link to said second firing member, the free end of the lever being arranged to engage said cocking member.

8. Firing mechanism for automatic guns of the kind described having a breech block and a breech ring, said mechanism comprising a cocking member moved into firing position by the closing of the breech block, a fire-control-device, a firing member mounted on the breech block and operated by said fire-contrcl-device, a second firing member mounted on the breech ring through which said first firing member is operated by said fire-control-device, an abutment formed on said second firing member engaging the side of the breech block until the breech block is closed and a catch preventing operation of said second firing member by said fire-control-device until said cocking member is in firing position and inoperative thereafter comprising a multiplying lever pivoted at one end to the breech ring, a link connecting said lever to said second firing member, the free end of said multiplying lever engaging said cocking member until said cocking member is in firing position whereby the respective distances from the pivoted end of the lever to the point of engagement with said cocking member a and to the point at which said link is connected to said lever constitute arms of the lever, and whereby the pressure exerted on the breech block by said fire-control-device through said second firing member and said abutment is reduced in the ratio of the arms of said lever.

9. In a gun of the kind described having a barrel arranged to recoil relatively to a support, and having a breech ring and a breech block, a cocking member moved into firing position when the breech block is closed, firing mechanism comprising a movable firing member pivoted on the breech ring and engaging the breech block, a trigger engaged and actuated by said firing member when the breech is closed, a fire-control-device forcing said firing member against said trigger, and a lever pivoted on the breech ring and engaging said cocking member until said cocking member is in firing position, linkage connecting said lever and said fire-control-device whereby trigger actuating movement of said firing member is prevented until the breech block is closed and said cocking member is in firing position, said lever and said linkage being so disposed that the force exerted by said lever on said cocking member is only a fraction of that which said fire-controldevice exerts on said firing member and on the breach block.

10. Firing mechanism for automatic guns of the kind described having a breech block and a breech ring, said mechanism comprising a cocking member moved into firing position by the closing of the breech block, a fire-control-device, a firing member mounted on the breech block and operated by said fire-control-device, a second firing member mounted on the breech ring and engaging the breech block through which said first firing member is operated by said fire-controldevice and a catch preventing said fire-controldevice from operating said second firing member l0 7 until said cocking member has been moved into firing position and inoperative thereafter comprising a multiplying lever pivoted at one end to the breech ring, a link connecting said lever to said second firing member, the free end of said lever engaging said cocking member whereby the respective distances from the pivoted end of the lever to the point of engagement with said cocking member and to the point at which said link is connected to said lever constitute arms of the'lever, and whereby the lateral pressure exerted on the breech block by said fire-control-device through said second firing member is reduced in the ratio of the arms of said lever, and a firing release catch engaging said fire-control-device to render said fire-c0ntroldevice inoperative after said first catch becomes inoperative to prevent firing of the gun until said firing release catch is disengaged from said fire-control-device.

11. In firing mechani: for automatic guns of the kind described having a breech block and a breech ring, a cooking member movable into and out of firing position as the breech block is closed and opened, a fire-control-device, a firing member on the block constructed and arranged to be operated by said fire-controldevice, a second firing member on the breech ring through which said first firing member is operated, and a catch device arranged to prevent said fire-controldevice and said second member from operating said first firing member until said cocking member has moved into firing position and the breech block is closed comprising a lever pivoted at one end to the breech ring and pivotally connected to said second firing member, the free end of said lever being arranged to engage said cocking member until said cocking member has moved into firing position.

12. In a gun of the kind described having a barrel arranged to recoil relatively to a support, and having a breech ring and a breech block, a cocking member, firing mechanism comprising a mOV- able firing member pivoted on the breech ring, a trigger engaged and actuated by said firing member when the breech is closed, means forcing said firing member against said trigger, and a lever pivoted on the breech ring and operatively connected to said firing member and engaging said cocking member whereby trigger actuating movement of said firing member is prevented until the breech block is in closed position.

13. In firing mechanism for automatic guns of the kind described having a breech block and a breech ring, a cocking member movable into and out of firing position as the breech block is closed and opened, a fire-control-device, a firing member on the block adapted to be operated by said firecontrol-device, a second firing member on the breech ring through which said first firing member is operated, and a catch device subject to the movement of the breech block to prevent said fire-control-device and said second member from operating said first firing member until the breech block is closed comprising a lever pivotally coupled to said second firing member, and means engaging said lever holding said second firing member away from said firing member when the breech block is open, said means being so constructed and arranged that said lever is released from engagement therewith upon closing of the breech block.

14. In a gun of the kind described having a barrel arranged to recoil relatively to a support, and having a breech ring and a breech block, a cocking member, firing mechanism comprising a mov- .1 1 1'2 able firing member-pivoted on the breech ring, a REFERENCES CITED mlggeriengagefi and'actuated by'sa'ld firing The following references are of record in the her "When'the'breech'is closed, means forcing said file ,this patent: firing "member against said trigger, a lever pivotally connected with said firing member, and 5 UNITE-ESTATES A ENTS means engaging said lever holding said firing N ber Name D t member away from said trigger Whensaid'breech 1,299,139 Epawsonfiet,a] App '1, 1919 block is ropen, said means being .so constructed 1525 065 Browning Feb. 3, 1925 and arranged 'that said lever is released from 2,135,005 Hoagland et a1 Nov. 1, :1938 engagemeni; therewith upon closingrof the breech 10 2,142,132 'Joyce Jan. 3, 1939 block. 2,186,969 Green -Jan. 16, 1940 'ZDESMOND WALTER MOLINS. 2,218,877 Ernesti et a1, Oct. 22, 1940

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