Patent GB-133695-A (GB)
IPC: F41A19/10
Abstract: 133,695. Pedersen, J. D. July 30, 1915, [Convention date]. Breech actions, sliding breech-block; indicating when loaded, means for; stocks.-Relates to automatic or semi-automatic fire-arms in which the breech mechanism is operated by the rearward kick of the cartridge shell acting through the breech-block upon a momentum slide, and consists (1) in a breech-block mounted in the slide and adapted to recoil therewith for a short powerstroke, whereafter the rear end of the breechblock is raised out of locking engagement with the frame, and is lowered again when the parts reach the corresponding position during the return movement; (2) in means for transmitting the rearward kick of the breech-block to the slide in such a manner that the frictional resistance betvceen the slide and the frame during the said kick or power-stroke is increased; (3) in means for arresting the breech-block for a short time after the power-stroke, and before its rear end is raised; (4) in a firing-pin mounted in the slide so as to project forwardly through the breech-block, with a firing-spring bearing forwardly against the breech-block and rearwardly against the slide; and (5) in a pivoted, spring-controlled extractor designed to form a visual or sensitive means for indicating the presence or absence of a cartridge in the chamber. The Specification also describes, but does not claim, an ejector formed on the upper edge of one of the side walls of a depending box magazine. In the form illustrated, the breech mechanism comprises an inertia slide C, Figs. 3 and 5, adapted to reciprocate on the frame B, and enclosing the barrel D, breech-block E, and firing-pin P. The breech-block E, the head 5<m> of which is slidably supported either on the frame B or from the slide C, is held in its forward position against the base of the cartridge by the co-operation of an incline 3<r>, Fig. 5, on the slide with an incline 5f on the rear of the breechblock. This device serves also to hold down the rear end of the breech-block so that a shoulder 5<j> thereon enters a recess in the top of the frame. The breech-block has a central vertical opening through which the depending arm 3
 of the slide is adapted to extend. On discharge, the empty cartridge-shell drives the breech-block rearwardly, and with it the slide, against the action of the return-spring 4<d> and the hammer-spring 8<e>, Fig. 3, until the breech-block is arrested by its shoulder 5<j> striking an abutment 2<f> on the frame. During this relatively short power-stroke, the upward component of the pressure between the faces 3<r> and 5<f> will increase the frictional resistance between the slide and the frame. The momentum of the slide causes it to continue its recoil alone after the breech-block has been arrested until an incline 33<f>, Fig. 5, on the slide engages an incline 5<k> on the block, and lifts the rear end of the block out of engagement with the abutment 2f on the frame. The slide and breech-block then recoil together to complete the opening movement, which is determined by the engagement of a shoulder 3<p>, Fig. 3, on the forward end of the slide with an abutment 2<f> on the frame. The slide and breech-block are returned by the spring 4<d>, forcing a fresh cartridge from the magazine M into the chamber 4<x>, the centring of the cartridge being assisted by an inclined guide-prong 5<y>, Fig. 19, on the face 5<m> of the breech-block. When the block is arrested by contact with the rear end of the barrel, an incline 33<c> on the slide coacts with the incline 5<f> on the breech-block, and depresses the block so that its shoulder 5<j> enters into locking engagement with the frame. The slide then continues its forward movement alone, the face 3<b> thereon holding the breech-block in its depressed position, and finally comes to rest with its face 3<r> in engagement with the incline 5<f> of the block. A roller 3<c> mounted on the slide is adapted to depress the hammer H on recoil. In a modification, the rear end of the breech-block is adapted to be raised into the unlocking position after the power-stroke by reason of a pivotal link connexion between the block and the slide. The firing-pin P is mounted in a bearing in the depending portion 3
 of the slide, and is held rearward by a spring 15<b> which bears at its forward end against the breech-block, thereby serving to hold the block in its upward position when it is interlocked with the slide. During the continued recoil of the slide after the breech-block has been temporarily arrested by the abutment 2<f>, the firing-spring 15<b> expands and pushes the firing- pin rearwardly with respect to the breech-block, and maintains it in this relative rearward position until the corresponding position of the parts is reached on the return motion of the breech mechanism. The firing-pin is thus prevented from reaching the base of the cartridge during the loading operation. The extractor 5<a>, Fig. 19, is pivoted at 5<x> in the breech-block, its claw 5<n> being urged inwardly into engagement with the cartridge-rim by the pressure on its rear end of a spring-pressed plunger 5<b> located in a recess in the breech-block, the line of pressure being eccentric to the pivot 5<x>. This device serves as a visual or sensitive means for determining the presence or absence of a cartridge in the chamber. The ejector comprises a lug 13<a>, Fig. 15, formed on the upper edge of one of the magazine walls, the lug being strengthened bv a raised or weldedon reinforcement. The ejection of the spent shell takes place through an ejection opening 3<a> in the slide C. The Specification as open to inspection under Sect. 91 (3) (a) comprises also (1) the subjectmatter of the divided Specification 154,611; (2) a barrel mounted in the slide without positive lock, with means for holding the barrel fixed relatively to the frame during the recoil and return strokes of the slide; (3) a magazine catch m, Fig. 3, and (4) stock-plates held by undercut lips on the sides of the frame B, and by the pin g. This subject-matter does not appear in the Specification as accepted.