GB781748A - Improvements in feed devices for automatic guns supplied with ammunition in the formof a cartridge belt - Google Patents

Abstract

781,748. Automatic guns. BREVETS AERO-MECANIQUES SOC. ANON. Dec. 6, 1955 [Dec. 16, 1954], No. 35003/55. Class 92. Relates to an automatic gun provided with means which obviate the jerky pull on the cartridge belt by the feed mechanism of the gun. According to the invention a fly-wheel 6, Fig. 1, is coupled in rotation by means of a torque limiting device with sprocket wheels 7 in mesh with a portion of the belt 4 located in a guide passage 5, the arrangement being such that during the time intervals for which the cartridge engaged by the belt feed mechanism 2 is stationary, sprocket wheels 7 push the cartridges towards the mechanism 2 and, during the time intervals when the cartridge belt is pulled by mechanism 2, wheels 7 partly exert a braking action on the cartridge belt. The clearance between the belt 4 and the inner walls of the passage 5 are such that when the feed mechanism 2 is stopped, the portion D of the belt can only take a slightly zig-zag shape, thus stopping the part of the belt engaged by the wheels 7 a short time after stopping of the mechanism 2. The shaft 8 of the wheels 7 is journalled in frame elements 9, Fig. 2, rigid with passage 5 and one end of the shaft 8 is coupled with the flywheel 6 through an epicycloidal gear, comprising, a sun-wheel 11 on the shaft 8, planet wheels 15 journalled in the flywheel 6 and a further sun-wheel 16 carried by a sleeve 17 freely rotatable around shaft 8 and bearing axially against the fixed frame through a thrust bearing 18. Annular friction discs 19, 20 alternately carried by the sleeve 17 and fixed frame constitute the torque limiting device; the limit of which can be varied by a nut 23 and spring washer 22. At the start of firing, the wheels 7, shaft 8 and planet wheels 15 start rotating and through sunwheel 16 exert a high torque on the sleeve 17. The friction between the discs 19, 20 oppose the rotation of the sleeve 17 and the planet wheels 15 gradually start the flywheel 6 rotating until sleeve 17 is stationary, and the wheels 7 rotate at nearly constant speed. On ceasing firing, the rotation of the flywheel is braked by friction between the discs 19, 20 which slip with respect to one another and the flywheel is in turn stopped.