US2818669A

US2818669A - Bolt lock for a rifle

Info

Publication number: US2818669A
Application number: US411524A
Authority: US
Inventors: Perry Claude Alfred; Wackrow Roger David
Original assignee: Birmingham Small Arms Co Ltd
Current assignee: Birmingham Small Arms Co Ltd
Priority date: 1954-02-19
Filing date: 1954-02-19
Publication date: 1958-01-07
Anticipated expiration: 1975-01-07

Description

Jan. 7, 1958 c. A. PERRY ErAL BOLT LOCK FOR A RIFLE:

2 Sheets-Sheet 1 Filed Feb. 19. 1954 lll/I Jan. 7, 1958 7.l A. PERRY ETAL BOLT LocK FOR A RIFLE 2 sheets-shet 2 Filed Feb. 19, 1954 iinited

patent Y

2,8%,669 Patented Jan, 7, 1953 BOLT LCK FR A RELE Claude Alfred Perry, Gitan, and Roger David Wackrow, Handsworth, Engiand, assignors to The Birmingham Smaii Arms Qompany Limited, Small Heath, Birmingham, England Appiication February 19, 1954i, Seriai No. 411,524

4 Cairns. (Ci. Liii-d6) This invention is concerned with improvements in or relating to bolt-action rifles, and is particularly concerned with the provision of safety mechanism therefor.

Safety mechanism of bolt-action rides is usually of a two-fold character. When it is desired to render the weapon inoperative, movement of the safety-catch locks the striker (usually by locking the cooking piece) and also locks the bolt. The principal feature of the present invention is directed to an improved way of looking the striker.

According to this invention a bolt-action riiie includes a two-part hollow bolt, the two parts being rotatably secured together, and a cam mounted on the rearward part of the bolt for rotation about a horizontal transverse axis, the cam being so located as to be capable of engaging a groove in a cooking piece when the bolt is in cocked position, thereby to prevent forward movement of the striker.

According to a feature of the invention, the cam is located in the lower half of the rearward part of the bolt, the upper part 'which is arcuate shaped to provide a track for the thumb piece for operating the cam.

According to a further feature of the invention, the cam causes rearward movement of the cooking piece, thereby to remove the cooking piece substantially from engagement with the sear when in cocked, but safe, position.

According to yet another feature of the invention, movement of the cam eects movement of an auxiliary member to lock the forward part of the bolt against rotation when the rifie is in safe position.

One construction in accordance with the invention will now be particuiarly described with reference to the accompanying drawings in which:

Fig. l is a sectional view through a bolt action rifle trigger mechanism;

Fig. 2 is a view of part of the mechanism shown in Fig. l with the safety catch in a different position;

Fig. 3 is a side view of part of a rifle from the other side;

Fig. 4 is a side View of a cooking piece;

Fig. 5 is a section through the cooking piece taken on line S-S in Fig. 4;

Fig. 6 is a view of the rear portion of the bolt from underneath;

Fig. 7 is a sectional side view of the rear portion of the bolt;

Fig. 8 is a side view of the cam shaft;

Fig. 9 is a front view of the cam shaft;

Fig. 10 is a section on the line 11E-1G in Fig. 9;

Fig. 11 is a section on the line 11-11 in Fig. 9;

Fig. l2 is a section through the rear portion of the boit and the cooking piece with the cam shown in full.

A bolt-action riiie according to this particular construction is provided with a two-part hollow bolt, the rear part 1 thereof being screw-threaded into the forward part 2 thereof. A firing pin 5 and a cooking piece 7 are located within the bolt and a striker spring 9 is disposed between the forward end of the rear part of the bolt and a projection 13 on the firing pin. The rear end portion of the cooking piece 7 is provided with a depending portion 3 which not only acts as a shoulder for abutting against a sear 21 when the bolt is in cocked position, but also acts so as to prevent rotation of the rear part of the bolt. Consequently, when it is desired to cock the rifle, the forward part 2 of the bolt is rotated with respect to the rearward part 1 and the whole moved rearwardly.

The rearward part of the bolt is provided in its lower half with a transversely-.extending hole 15 within which a cam shaft 17 is located. This cam shaft forms part of a safety catch 19 and may be rotated by a thumb piece 10 at the side of the rearward part of the bolt. The rear upper portion 11 of this part of the bolt is arcuate in profile and is chamfered and thus provides a track over which the thumb piece 10 may move. Normally the cam shaft 17 allows free movement of the cooking piece during movement of the bolt in order to cock the rie (as illustrated in Fig. l), but rotation of the cam shaft when the bolt and cooking piece are in cocked position allows the cam portion 17 of the shaft to enter into a groove 15a in the cooking piece. At the same time the cam portion of the cam shaft engages the shoulder S formed by the rear wall of the groove 15a and causes the cooking portion 3 of the cooking piece 7 to move rearwardly from its cocked position for only a short distance. The distance, is, however, suloient to remove the shoulder 23 of the cooking piece away from the scar 21, thereby not only to prevent unnecessary pressure on the sear, but also to allow the sear to ride upwardly under the influence of a spring urged lever 24 until it lies within a narrow groove 25 formed in the rear end of the forward part of the bolt. The engagement of the Sear with this groove prevents rotation of the forward part of the bolt when the rifle is in cocked position with the safety catch applied.

By mounting the cam shaft 17 so that its axis is in the lower half of the rearward part of the bolt, it is possible to use a low-mounted telescopio sight without interference from the thumb piece 19 which operates the cam shaft. At the same time, by providing an arcuate chamfered track for the thumb piece there is little likelihood of the thumb piece accidentally being moved from one of its positions to the other.

A spring loaded plunger 27 mounted in a hole 31 in the rear portion 1 of the bolt is adapted to engage a slot 29 formed in part of the safety catch 19 whereby the safety catch is retained in the firing position.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent is:

l. A bolt action riiie comprising a hollow bolt composed of forward and rear parts rotatably secured together, a Sear, a cooking piece therefor provided with a depending portion reciprocable within the bolt and having a groove extending transversely in its rear portion and a shoulder rearwardly of said groove, and a safety catch having a cam thereon and located in the lower half of the rear part of the bolt for rotation about a horizontal transverse axis, the catch including a thumb-piece and the cam being rotatable by said thumb-piece into a position to aline with the groove in the cooking piece to permit cooking of the cooking piece while the bolt is in cocked position, and rotatable into another position to abut against said shoulder and thereby prevent forward movement of the cooking piece.

2. A bolt action rifle as defined in claim l, wherein the upper surface of the rear part of the bolt is arcuate about the axis of the cam to provide a track over which the thumb-piece of the catch moves for rotating the cam.

3. A bolt action riiie as defined in claim 1, wherein the cam actuated by the catch causes rearward movement of the cooking piece, thereby to move and hold the cock- References Cited in the le of this patent UNITED STATES PATENTS 830,587 Hamilton Sept. 11, 1906 15 4 Hammond Feb. 18, 1919 Seitz Dec. 19, 1944 Wilcox Oct. 18, 1949 Ackerson Aug. 18, 1953 FOREIGN PATENTS Great Britain 1893 Germany Sept. 9, 1940