US2536997A

US2536997A - Pivoted lock mechanism for breech bolts of automatic firearms

Info

Publication number: US2536997A
Application number: US713958A
Authority: US
Inventors: Lippert Hanns; Hepperle Erwin
Original assignee: Werkzeugmaschinenfabrik Oerlikon Buhrle AG
Current assignee: Rheinmetall Air Defence AG
Priority date: 1945-12-06
Filing date: 1946-12-04
Publication date: 1951-01-02
Anticipated expiration: 1968-01-02
Also published as: DE844559C; BE469639A; CH275693A; GB618757A; CH261658A; FR937798A; NL71848C

Description

Jan. 2, 1951 H. LIPPERT ET-AL 2,536,997

PIVOTED LOCK MECHANISM FOR BREECH BOLTS or AUTOMATIC FIREARMS 3 Sheets-Sheet 1 Filed Dec. 4, 1946 ml f mi, v n/ /m/ A 8 Jim. 2, 1951 H. LIPPERT EI'AL PIVOTED LOCK MECHANISM FOR BREECH BOLTS 0F AUTOMATIC FIREARMS 3 Sheets-Sheet 2 I Filed m. 4, 194a fnvenzons 6- L/ pert, any, 5 Mm Alta/5' PIVOTED [:OCK MECHANISM FOR BREEC BOLTS OF AUTOMATIC FIREARMS Jan. 2, 1951 H LIPPERT ETAA. 2,536,997

Filed Dec. 4, 1946 3 Sheets-Sheet 5 A A A A A A A A 4 i I v v v v v v v v 7 V/Ifo/S lob barf, and.

Patented Jan. 2, 1951 UNITED STATES PATENT OFFlCE PIVOTED LOCK MECHANISM FOR BREECH BOLTS OF AUTOMATIC FIREARMS Application December 4, 1946, Serial No. 713,958 In Switzerland December 6, 1945 18 Claims. 1

The present invention relates to an automatic firm-arm with one-piece breechblock, in which the locking of the breechblock is effected in a novel way by means of a locking mechanism of extremely simple design. The automatic firearm with one-piece breechblock is characterised by the feature that for bringing the breech look into locking position at least one energy accumulator is provided, consisting of two parts connected by an energy-accumulating organ, the rear part holding the lock in the open position, while the front part catches behind the lock fitted in a seat of the breech casing, thus keeping up the pre-tension of the energy-accumulating organ, in such a manner that the breechblock on its forward run, under tension of the energy accumulator, moves the rear part of the energy accumulator to an extreme forward position, thus removing the rear part of the energy accumulator out of the position in which it keeps the lock open as soon as the breechblock comes close to its forward reversal position, the lock is moved into locking position by the front part of the energy accumulator, unstressing in so doing the energy-accumulating organ, and, as the breechblock reachesthis position, the lock is caught underneath and held in looking position by the front part of the energy accumulator.

The appended drawing shows in Figs. 1-15 several constructional examples of the subject of the invention.

In this drawing:

Fig. l is a longitudinal section through an automatic firearm with one-piece breechblock, in

schematic representation;

Figs. 2-4-various positions of the breechblock on an enlarged scale; Fig. 2 showing the breechblock at the moment it engages the rear part of the energy accumulator, while Fig. 3 shows the parts in the position in which the rear part strikes the front part of the energy accumulator, Fig. 4 showing the result of the rebound of the front part of the accumulator in the cammin-g upwardly of the locking means into the operative position.

Fig. 5 is a section along line I-I in Fig. 4;

Fig. 6 is a section along line II--II in Fig. 4;

Fig. '7 shows the breechblock at the forward limit of its movement with the locking means held in the operative position by the front part of the energy accumulator;

Fig. 8 illustrates the action of the gas-operated rod on the front part of the energy accumulator whereby the locking means are released;

Fig. 9 shows the locking means cammed into 2 the inoperative position by the rear surface of the breechblock with the rear part of the energy accumulator about to overlap the locking means;

Fig. 10 shows the seating of the lock on an enlarged scale;

Fig. 11 is a section along line III-III in Fig. 9;

Fig. 12 shows an automatic fire-arm, in section, according to a second constructional example;

Fig. 13 shows on an enlarged scale a position of the breechblock according to the constructional example of Fig. 12 just after the release of the locking means;

Fig. 14 is a section through the breechblock casing with breech and the organs locking the latter, in the alternative with two locks; while Fig. 15 shows a modification of the construction according to Fig. 14 with the locking means arranged to engage a forward portion of the breechblock.

I-in Fig. ldesignates the barrel inserted in known manner in the breech casing 3 by means of a bayonet joint 2. Within the breechblock casing 3 slides the breech 4 under the action of a recuperating spring 5. S designates schematically the trigger mechanism. In the breech casing 3 is fitted an energy accumulator consisting of the two parts i and 8 connected together by means of an energy-accumulating organ, a spring 9, by Way of example. Hi designates the look fitted in a seating ll of the breech casing. The breech casing is slidingly fitted in a cradle i2 so as to recoil against the action of a spring l3.

As shown in Fig. 6, the two parts 'i' and 3 constitutin-g the energy accumulator are fitted in the breech casing 3, laterally of the breechblock, the rear part 8 resting on rails It of the front part i of the energy accumulator. The rails it are connected together at the rear ends by a web (bridge) l5, by means of whicn they seize behind the lock it at its face it (see Figs. 1, 2, 9 and 10). The rear part 8 resting-as already mentionedon the rails 14 of the front part i, and fitted in the breecnblock casing laterally of the breechblock (see Fig. 6), is provided with shouders it coming in contact with stops it; of the breechblock 4.

The rear part 8 of the energy accumulator, during the forward travel of the breechblock, overlaps a projection I9 of the lock IE3. The lock It] itself is provided with a slanting face 2@, which in the locked position of the breech contacts another slanting face 2i of the breech block 4. These two faces are shaped so as to be selfunlocking, in other words, should a force acting For the purpose of supporting the lock iii there 7 is further fitted in the breech casing 3 a body 33 (Fig. 11) preventing the look from being pulled out of the seating ill by the front part of the energy accumulator.

The working of the constructional example of an automatic fire-arm with one-piece breech block shown in Figs. 1-11, is as follows:

As already mentioned, the two parts i and 8 of the energy accumulator are connected together by the spring ii standing under a permanent definite pie-tension. In the position represented in Fig. 2 the breech block is on its forward travel and, with its stops i8, comes into contact with the shoulders if of the rear part 8 of the energy accumulator. During the forward travel of the breech block the lock it itself-owing to the fact that the rear part 8 of the energy accumulator is resting on its projection l-is prevented from moving against the breech block, in other words, friction between breech block and lock which might impair the firing rate, does not arise. This is necessary because the front part i of the energy accumulator catches underneath the lock with its web l5, also over slanting facesand on the other hand the front part '5 is pressed forward by the spring 9, so that the lock l9 by itself, without the overlapping through the rear part 8 of the energy accumulator, would tend to move upward.

In the course of the further forward travel of the breech block t the rear part 8' of the energy accumulator is driven forward through the shoulders ll, thus tensioning the spring 5} (see Fig. 3). This movement of the rear part 8 at the same time releases the lock it, since the rear part 8 of the energy accumulator is removed from the projection E9 of the lock it, no longer overlapping it. During the further forward travel of the breech block the rear part 3 of the energy accumulator strikes with sharp impact on the front part i of the energy accumulator, thus bringing about a jarring blow initiating the locking movement, insofar as the front part i of the energy accumulator is now rigidly connected with the breech block t on its forward run and compulsorily accompanies it on its forward movement, thusthrough the web is gliding off at the slanting face it of the lock lll-causing the lock to be pressed upwards. This lasts until the breech block 4 reaches its front reversal position. The further locking movement is now brought about by the unstressing of the spring t pressing forward the front part E of the energy accumulator, thus moving the lock iii into its locked position.

Fig. 3 shows the manner in which the two parts i and 8 of the energy accumulator engage one another, while in Fig. i a slight unst-ressing of the energy-accumulating organ has already taken place, the lock it, however, being already in the completely locked position. The web iii now underlaps the lock, the spring 9 being further unstressed, as shownin Fig. 7. The furcording to Figs. 1 to 11-.

ther movement of the front part i of the energy accumulator causes the tilting lever 2 5, and consequently also the double lever 25, to swing, whereupon ignition is effected.

Upon release of the shot. a gas rod 28 (Fig. 8) presses back the front part 1 of the energy accumulator, tensioning the spring and depriving the lock Iii of its underlapping through the web i5 and-causing it to swing downward under the action of the remaining gas pressure forces, since the faces 28 and 2i by which it bears on the breech block i, are self-unlocking. ihis is due to the fact that the direction of the force transmitted by the breech block to the lock it forms with the straight line connecting the center of the force-transmitting area of the engaging sur faces 2%, 2i and the fulcrum of the lock, an angle which is greater than the angle of friction, so that upon removal of the underlapping portion it of the front part i of the energy accumulator from under the lock, unlocking occurs automatically. As soon as the lock it has reached its bottom position it is overlapped by the rear part 8 of the energy accumulator which, through the rearward movement of the breech block 4, is now enabled to carry out a rearward movement, unstressing the spring 9, thus returning to the starting position as shown in Fig. 2.

In the constructional example according to Figs. 12 and 13, the return of the front part 'i of the energy accumulator: after release of the shot, for removing the underlapping of the lock iii, is not brought about by a gas rod 26', but by a double lever 2i; seated in the breech casing 3, which lever rests with a head 30 in a corresponding recess of the front part 1 of the energy accumulator, in such amanner that during the recoil of the weapon the lower part 3! of the double lever 25* hits the stop 32 rigidl fitted on the cradle, thus driving rearward the front part i of the energy accumulator, as described above.

For the rest, all functions are the same in this constructional example as in the constructional example according to Figs. 1 to 11.

Fig. 14 shows a constructional example in which the breech block 4 is locked by two looks it. These two locks'are laterally arranged in the breech casing 3 and are actuated in exactly the same way as in the constructional example ac- They catch behind the breech block 3 at its rear part. With a view to shortening the length of the weapon, the constructional example according to Fig. 15 provides for the locks It to catch behin the breech block 3 at its front part. Here again, the functions of the other parts carrying out the locking process are exactly the same as in the constructional example according to Figs. 1-11.

The constructional examples described above clearly show that through the new locking method by means of a two-piece energy accumulator, and the play of these two parts of the energy accumulator in relation to one another, in the course of the various functions, the locking process can be carried through in the simplest mannor, the locking being secured in an absolutely reliable manner during the release of the shot. Furthermore, this breech mechanism-as can be clearly seen from the descriptionis lacking in inertia to such a degree that it will work reliably even at the highest firing rates.

We claim:

1. Automatic fire-arm comprising a casing, a

the breech block to the casing, mechanism for moving the locking means into locking position comprising at least one energy accumulator having a front and a rear part acted upon by an energy-accumulating organ, the rear part of the energy accumulator being arranged to hold the locking means in the open position, while the front part of the energy accumulator is adapted to catch behind the locking means, and means for moving the rear part of the energy accumulator forwardly on the forward run of the breech :block, whereby the energy accumulator is placed under tension and the rear part of the energy accumulator is moved out of the position in which it keeps the locking means in the'open position, the front part of the energy accumulator being slidable under the action of the tensioned organ, as soon as the breech block comes into proximity of its front reversal position, to move the looking means into locking position, the locking means in the front reversal position of the breech block being underlapped by the front part of the energy accumulator and thereby held in looking position.

2. Automatic fire-arm according to claim 1, wherein the two parts of the energy accumulator are arranged so as to leave such an interval between them that upon tensioning of the energyaccumulating organ by the forward movement of the breech block they will strike on one another when the breech block comes close to its front reversal position, whereby the movement of the locking means into locking position is initiated by the breech block hitting the front part of the energy accumulator by way of the rear part of the energy accumulator with a jarring blow.

3. Automatic fire-arm according to claim 1, wherein the rear part of the energy accumulator is provided with a shoulder arranged to overlie the locking means in its inoperative condition to prevent it from moving against the breech block.

4. Automatic fire-arm according to claim 1, wherein the locking means comprises a pivoted member swing able into and out of locking position, and wherein the surfaces along which the locking means and breech block engage are inclined in such manner that the direction of the force transmitted by the breech block to the looking means forms with the straight line connecting the center of the force-transmitting area of such surfaces and the fulcrum of the locking means an angle which is greater than the angle of friction, so that upon removal of the underlapping of the locking means by the front portion of the energy accumulator, unlocking occurs automatically.

5. Automatic fire-arm according to claim 1, wherein the faces along which the locking means and the breech block engage each other are inclined to the direction of rearward travel of the breech block to such a degree that upon removal of the underlapping portion of the front part of the energy accumulator from under the locking means, the latter is automatically cammed out of locking position by the rearwardly traveling breech block.

6. Automatic fire-arm according to claim 1, including a striker mounted on the breech block, the front partof the energy accumulator being arranged to move the striker into firing position as such part moves into its end position underlapping the locking means.

7. Automatic fire-arm according to claim 1, wherein locking means for the breech block are provided on each side thereof, and an energy accumulator acting on each of said locking means.

8. Automatic fire-arm according to claim 1, wherein locking means for the breech block are provided on each side thereof, and an energy accumulator acting on each of said locking means, the locking means engaging the breech block at its rear end.

9. Automatic fire-arm according to claim 1, wherein locking means for the breech block are provided on each side thereof,-and an energy accumulator acting on each of said locking means, the locking means engaging the breech block at the front thereof.

10. Automatic fire-arm according to claim 1, including a rod actuated by gas under pressure from the barrel for initiating unlocking of the locking means, said rod being arranged to engage the front part of the energy accumulator to move said part out of the position in which it supports the locking means in the operative position.

11. Automatic fire-arm according to claim 1, including a cradle for slidably supporting the breech casing, a stop on the cradle, a lever pivoted on the breech casing and engaging the front part of the energy accumulator and arranged to strike said stop during the recoiling movement of the breech casing, whereupon said lever operates to 'move the front part of the energy accumulator out of the position in which it supports the looking means in operative position.

12. Automatic fire-arm comprising a cradle; a breech casing slidable on the cradle; a breech block slidable in the casing; and means for looking and releasing the breech block and comprising a locking member seated in the breech casing and normally disposed out of the path of the breech block, and an energy accumulator including a front part, a rear part, and a compression spring disposed between said parts, the rear portion of the front part engaging the locking member along inclined surfaces of such shape that the locking member is urged into locking position, the rear part having a portion normally overlying the locking member to hold the same in inoperative position, and means actuated by the breech block on its forward travel to shift the rear part of the energy accumulator to cause release of the locking member and to compress said spring, whereupon said locking member is urged into locking position by the front part of the accumulator under the action of said spring.

13. Automatic fire-arm according to claim 12, including means actuated by the pressure of the explosion gases in the barrel to shift the front part of the accumulator rearwardly to release the locking member.

14. Automatic fire-arm according to claim 12, wherein the locking member is shaped to receive the rear portion of the front part of the accumulator beneath it when it has been shifted into locking position, whereby the locking member is locked in looking position.

15. Automatic fire-arm according to claim 12, wherein the locking member engages the breech block along inclined surfaces which cam the looking member into unlocking position upon release of the locking member and under the action of the gas pressure on the breech block.

16. Automatic fire-arm according to claim 12, including mechanism operative after the firing of the shot to move the front part of the accumulator rearwardly to release the locking member.

17. Automatic fire-arm according to claim 12,

wherein an energy accumulator :is disposed upon opposite sides of the breech block.

18. Automatic fire-arm comprising a cradle; a, breech casing slidable on the cradle; a breech block slidable in the casing; and means for locking and releasing the breech block and comprising a locking member supported on the breech casing and normally disposed out of the path of the breech block, and a floating energy accumulator including .a front part and a rear part movable relative to each other and both slidable in the casing, and a compression spring disposed between said ,parts, the rear part holding the locking member in inoperative positionand being movable by the breech block as it approaches its forward reversal position to release the locking member, While simultaneously compressing the spring, the front part engaging the locking memher and acting under the pressure of the so-compressed spring to cam the locking member into locking position, means operative upon firing of a cartridge to move the .front part rrearwardly REFERENCES CITED The following references are of record in th file :of this patent:

"UNITED STATES 'PA'IYENfIS Number Name ,Date

2,202,201 Henning May28,1 9,4r1

FOREIGN PATENTS Number Country Date 489,,75-2 Great Britain Aug. 3, 1938 706,158 Germany May 19, 1941