Title of Invention: Automatic firearm breech mechanism

Technical Field

[0001] The invention concerns an automatic firearm's breech mechanism, suitable mainly for small caliber automatic firearms whose breech is slowed by a roller.

Background Art

[0002] The design of an automatic firearm's breech mechanism described in SK287526 patent documentation consists of a shaped opening, created in a locking block permanently attached to the barrel, in which the breech is placed along the barrel's longitudinal axis. A groove, where a delaying roller slides in when the breech is the locked position, is created on one of the horizontal walls of the shaped opening. The delaying roller is a moving part placed vertically between the rear vertical wall of the breech and the front vertical wall of the breech carrier. There is a supporting surface on the opposite wall of the shaped opening, on which the breech slides with its lower wall. Therefore, when the firearm is assembled, the delaying roller's working area is constrained by the walls of the shaped opening created in the locking block by the breech and the breech carrier, whereas in the vertical direction, the delaying roller's movement is constrained by the walls of the shaped opening and the breech.

[0003] The delaying roller is placed loosely between the rear vertical wall of the breech and the front vertical wall of the breech carrier. Therefore, during the fire arm's disassembly, e.g. when it is being cleaned, the delaying roller, after removing the breech mechanism from the fire arm, is not tied to the breech mechanism in any way. This could result in losing the delaying roller.

[0004] These considerations gave rise to the task of searching for such a design of an

automatic firearm's breech mechanism with a roller-delayed breech which will allow the delaying roller to perform its function and which will at the same time ensure that the delaying roller will remain an integral part of the breech mechanism after removing the breech mechanism from the fire arm.

Summary of Invention

[0005] The drawbacks mentioned above are largely removed by the automatic firearm

breech mechanism featuring a breech, a breech carrier and a delaying roller that is positioned between the rear vertical wall of the breech and the front vertical wall of the breech carrier, moving vertically, as introduced by this invention, whose essence is that the cage surrounding the delaying roller's working area between the rear vertical wall of the breech and the front vertical wall of the breech carrier is modified.

[0006] Further, the essence of the invention is that the cage consists of a strip bent into the shape of the inversed letter U, featuring an opening created on its horizontal wall, while its vertical walls are fitted with a slide stop at both ends.

[0007] Finally, the essence of the invention is that the width of the opening is smaller than the delaying roller' s diameter.

[0008] The advantage of the automatic firearm breech mechanism this invention introduces is that it ensures that the delaying roller remains an integral part of the breech mechanism after removing the breech mechanism from the fire arm, thus preventing it from falling out of the breech mechanism. At the same time, it allows the delaying roller to fully perform its function.

Brief Description of Drawings

[0009] The invention will be further clarified using drawings, where

Fig.l

[0010] [fig.1] illustrates a perspective view of the cage mounted in the breech mechanism.

Fig.2

[0011] [fig.2] illustrates a perspective view of the cage itself.

Description of Embodiments

[0012] The automatic firearm breech mechanism features a breech 3, a breech carrier 4 and a delaying roller 2 that is positioned between the rear vertical wall 32 of the breech 3 and the front vertical wall 41 of the breech carrier 4. A modified cage 8 surrounding the delaying roller' s 2 working area is between the rear vertical wall 32 of the breech 3 and the front vertical wall 41 of the breech 3 carrier 4, moving vertically. The cage 8 consists of a strip bent into the shape of the reversed letter U, featuring an opening 82 created on its horizontal wall 81, while its vertical walls 83 are fitted with a slide stop 84 at both ends. The width of the opening 82 is smaller than the delaying roller' s 2 diameter.

[0013] It will be understood that an example of a particular embodiment of the invention is illustrated only for illustration and not as a limitation of the scope of protection of this invention.