GB475049A - Improvements in or relating to automatic guns having a pneumatically actuated sear mechanism - Google Patents

Abstract

475,049. Machine guns. WERKZEUGMASCHZNENFA73RIK OERLIKON. May 11, 1936, No. 13309. Convention date, March 26. [Class 92 (ii)] Pneumatically-controlled sear mechanism particularly for machine guns on aircraft fired by a remote trigger has a pressure cylinder 1 on the gun which is connected by a port or valve with the atmosphere as soon as the trigger is released so that limited bursts only are fired. Further, a second cylinder 1u on the gun is supplied with air under pressure acting through a piston 3 to release a bolt S which locks the sear mechanism in non-firing position. In the form shown, pressure air is supplied by a pipe 5 under the control of a remote trigger. The air passes to the front of the cylinder 1u to remove the locking bolt S from a recess in a piston member 2 connected by a rod 13 to the cam N which in known manner operates to release the sear H, the piston 2 being then moved rearwards by the air pressure acting on its front face. When the trigger is released, air escapes through a permanent leak 1d and the piston returns under the action of a spring 12 carrying with it by the action of a pawl 8 a sleeve 17. A port 4c in the piston thus registers with an air escape port 1c permitting a quick return of the piston to locked position. The pawl 8 then rides off the sleeve valve which is returned to its original position by a spring 10.