GB125435A - Improvements in or relating to Machine-guns and the like. - Google Patents

Abstract

125,435. Logan, H. T. July 21, 1916. Machine guns.-Relates to means for regulating the speed of discharge of that class of machine guns in which a member is reciprocated automatically and fires the gun when driven forwards by a spring stressed during the previous rearward movement. According to the invention, the firing movement of the reciprocating-member is retarded by a dash-pot having a release-valve which is increasingly opened to accelerate the rate of fire as the hand trigger is moved further back. The invention is shown applied to the reciprocating piston-rod member A of a Lewis gun which is held in the rearward position by a pivoted sear B engaging a bent A<2> and controlled by a trigger C. A second sear D engaging the bent A<2> is actuated by a spring-controlled air dash-pot F, F<1>, the piston of which, after a predetermined interval, engages a toe piece D<1> on the sear D to permit the piston-rod A to move forwards to fire the cartridge. A projection A<3> on the piston-rod engages a trip H<3> to energize the spring F<2> of the dashpot during the recoil movement of the piston-rod. The dash-pot, which is provided with a one-way valve G<1> to allow air to pass freely out of the dashpot, is furnished with a needle-valve G to time the flow of air into the dash-pot. The needle valve is operated by the sear B to decrease the dash-pot effect as the pressure on the trigger C is increased. The sear D is positively actuated through a pin D<3> by extreme movement of the trigger C, the dash-pot being then inoperative. Specifications 21743/00 and 27422/06 are referred to.