US1987939A

US1987939A - Machine gun

Info

Publication number: US1987939A
Application number: US682711A
Authority: US
Inventors: Lahti Aimo Johannes
Original assignee: Individual
Current assignee: Individual
Priority date: 1933-05-22
Filing date: 1933-07-28
Publication date: 1935-01-15
Anticipated expiration: 1952-01-15
Also published as: FR764199A; GB424565A; BE398478A

Description

Jan. 15, 1935. A. J. LAHTl 1,937,939

MACHINE GUN Filed July 2 8, 1933 2 Sheets-Sheet 1 ililillll Patented Jan. 15 1935 PATENT OFFICE MACHINE GUN V A V Aimo Johannes Lahti, JyvaskyIa, Finland Application July 2s, 1933, Si n No. 682,711

In Finland May 22, 1933 3 Claims. (C l 42-4) It isik-nown that troubles such as occur in the use of machine gunsconstructed according to the recoil system, are due to the large number of parts and the thus complicated construction of 2'5; the same.

Another objection, especially as to machine guns of large caliber is that the operator on setting the lock piece is compelled topull simultofore it-has not Ibeen possible to set the lock piece without moving the sliding device and the barrel.

g The imprbvedymachine gun constructed according-r to..-my invention is composed of a much 1 smaller number of: parts than any other machine gun; may bev readilyoperatedand is not likely to getjout of order.

Another -advantage gained by my improved machinegun is that ,it is now possible, solely by changing the magazine support, to use both straight and gcylindrical magazines and, if also thebarrel .is changed, to fire with cartridges of various calibers.,, Further, the mechanism is so constructed,.th'at the same can be used also for r the largestsize of cartridges in machine guns of large caliben. ,1 i l In-the machine gun according to my invention the barrel and the sliding device are rigidly connected and, move a, short distance to and fro. The sliding device is of improved construction and such that the lock piece, the lock pressing rod, the cooking bolt, the bolting piece, and the bolting piece depressor are situated inside and are movable with the same. The construction is such that the machine gun may be set automatically solely by the aid of the lock pressing rod without moving the sliding device and the barrel. The rigid connection between the barrel and the lock piece is established when the lock piece has moved so far forward that the setting sill of the lock pressing rod has forced the rear end of the bolting piece to rise in front of the support cam of the sliding device, the setting sill establishing the rigid connection. The movement of the cocking bolt being compulsory and simultaneous with that of thelock pressing rod, the cooking bolt will immediately, as soon as the rigid connection has been established, hit the percussion cap, and it is thus impossible that an unexploded cartridge could remain in the hot barrel.

By the influence of the recoil caused by the powder gases the front wall of the sliding device will strike against the upper end of the connecting lever and said lever will again strike against the lock pressing rod with such force that said gtaneously ,all of the interior mechanism, as here-;

rod will be brought into its rear position with its'spring compressed. When the lock pressing rod movesrearwardly the rigid connection is broken and the bolting piece depressor will press down the bolting piece.

The accompanying drawingsillustrate an embodiment of'the machine gun according to the invention.

Fig.1 is a side elevation of my improved machine gun. I

Fig. 2 is a longitudinal section of thesame.

Fig. 3 is a detail side elevation of the lock pressing rod.

Fig. 4 isa detail plan of the'same.

Figs. 5 and 6 are detail elevations of the bolting piece depressor.

Preparatory to firing, the machine gun is set by the aid of a setting lever l which is movable in a groove-of the bottom of the casing. On pull ing the setting lever '1 rearwardly the stud 1c of the setting lever moves rearwardly in the slot 211. in the under side of the lock pressing rod 2 until it reaches the rear end of said slot and then pulls the" lock pressing'rod 2 rearwardly, the setting sill Zbbeing moved along the lock pressing rod 2 which is under the bolting piece. The cocking bolt 13 that is anchored, between the abutments 2h and 21' of the lock piece 6 will be compelled togfollowthe movement of the lock pressing rod so that on the latter moving rearwardly the point of the cocking bolt 13 is pulled into the lock piece 6. The lock pressing rod 2 having moved so far rearwardly that the bevelled surfaces 20 of the grooves in the sides of the lock pressing rod engage the abutments 4a of the lower arms of the bolting piece depressor 4, the bolting piece depressor will be pressed down thereby also compelling the rear end 3a of the bolting piece 3 that is supported against the supporting surface 5a of the sliding device 5 to move downwardly. The rigid connection is hence broken and the lock piece 6 will now follow the movement of the lock pressing rod 2 rearwardly. The barrel 7 and the sliding device 5, threaded together that have not been moved during the setting, are held against casual movement by the spring 8 of the pressing rod 9 of the sliding device. When the lock pressing rod 2 has moved so far rearwardly that the setting sill of the holder 10 of the lock pressing rod has risen in front of the setting shoulder 21 of the lock pressing rod 2 the machine gun is cooked and the spring 11 of the lock pressing rod 2 that also acts as cocking spring, is likewise set.

Now the magazine may be inserted in the known manner.

The cartridge is fired by pulling the trigger 12, which releases the holder 10 of the lock pressing rod, so that the set lock pressing rod 2 is freed. The spring 11 thereupon forcibly moves said rod 2 forwardly. The lock pressing rod 2 moves the lock piece 6 forwardly therewith, so that the bolting piece 3 is lowered and the bevelled surface 31) at the lower face of the bolting piece, 3 lies against the bevelled surface of the setting sill of the lock pressing rod. The upper face of the sliding device 5 preventsthe bolting piece from rising which it tends to do during the forward movement of the lock piece.

The forward movement of the lock piece 6 thrusts the cartridge into the breech chamber of the barrel.

When the lock piece 6 has reached its fore-,

most position the bevelled surface 29 of the setting sill of the lock pressing rod 2 serves to lift the rear end 3a of the bolting piece 3 against the support surface 5a of the sliding device 5, and hence the rigid connection between the barrel 7 and the lock piece 6 is established. Now, when the lock pressing rod 2 moves further forwardly, its setting sill 2b reaches a point under the rear end 3a of the bolting piece 3 and thereby prevents falling of the bolting piece 3, thus establishing the rigid connection. After the rigid connection has been secured and the lock pressing rod 2 moves further forwardly the cocking bolt 13, situated between the abutments 2h, 2i of the lock pressing rod 2, strikes the percussion cap and the cartridge is fired.

When the cartridge has been fired the barrel 7, the sliding device 5 and the lock piece 6 begin their rearward movement while the rigid connection between the barrel 7 and the lock piece 6 is still unbroken. While the sliding device 5 is moving backwardly its front wall 5b presses the connecting lever 14 rearwardly so that its upper end 1411 gives the lock pressing rod 2 a rearwardpush.

When the lock pressing rod 2 moves rearwardly the abutments 2h, 2ion its upper face compel the cockingbolt 13 to be pulled into the lock piece 6.- While the lock pressing rod 2 continues its rearward movement the parts will operate in the same manner as described above with reference to the setting, with the exception, however, that the batrel 7 and the sliding device 5, as soon as the rigid connection has been broken, will by the action of the pressing rod 9 of the sliding device return into their foremost position.

In rapid firing the machine gun continues to operate as long as the trigger is being pulled.

I claim:

1. In a firearm of the class described, a casing, a barrel arranged for longitudinal movement, a lock pressing rod longitudinally movable in the casing and having a cam, a spring to move the lock pressing rod forwardly, a lock piece on the lock pressing rod, movable therewith and also movable to a limited extent longitudinally and independently of said lock pressing rod, a bolting piece arranged at the rear end of the lock piece, pivotally connected thereto, and movable by the cam of. the lock pressing rod, a firing pin carried by the lock piece, movable longitudinally to a limited extent independently thereof and also movable to a limited extent by the lock pressing rod, a sliding device in rear of the lock piece and engageable by the bolting piece when the latter is moved by the cam of the lock pressing rod during forward movement of the latter to thereby effect a rigid connection between the lock piece and the breech of the barrel, a spring to prevent casual rearward movement of the sliding device and'trigger mechanism to lock the lock pressing rod in cocked position against the compression of its spring.

2. A'firearm as claimed in claim 1,.including a bolting piece presser arranged between the rear end of the lock piece and the front end of the sliding device and arranged above the bolting piece, said bolting piece presser having a depending arm provided with an inwardly extending lug and said lock pressing rod having a groove in one side in which said lug operates.

3. A firearm as claimed in claim 1, in which the firing pin has a rearwardly extending arm provided with an enlarged portion and the lock pressing rod has a pair of spaced shoulders between which said enlarged portion of said arm is arranged, the space between said shoulders being somewhat longer than said enlarged portion of said arm.

AIMO JOHANNES LAHTI.