GB576684A - Improvements in and relating to servo-mechanism for actuating turrets, gun mountingsand the like - Google Patents

Abstract

576,684. Gun mountings. NASH, A. G. FRAZER-, (formerly NASH, A. G. F.). Dec. 20, 1937, No. 35255. [Class 92 (i)] [Also in Group XXIX] Relates to the valve mechanism of hydraulic motor control means for aircraft and other gun mountings of the kind in which there is a prompt response for low speeds and small angular movements and a delayed response for high speeds and large angular movements. According to the invention, the delayed response is obtained by a dashpot associated with the moving element of the valve controlling the direction of flow of liquid through the motor. The invention is shown applied to an aircraft gun mounting of the " ring " type, the gun ring 1, Fig. 2, carrying the hydraulic training motor 4 and the controlling valve box 6 together with a hand grip 7 for operating the valve. The hand grip shown in detail in Fig. 3, has a trigger-lever 16 actuating a bell-crank lever 24 connected by a rod 26 to a master-valve 36, Fig. 8, for admitting pressure liquid to the control valve 57. The valve 57 is operated by turning the hand grip after movement of the trigger-lever has released a locking- bolt 17. Rotation of the hand grip turns a lever 13, 14 connected by a rod 32 and shaft 29 to an arm 40 which moves the valve 57 to control the motor 4. The valve 57 is centralized by successively-acting springs 60, 59 which enable the change from slow to fast training to be felt by the gunner. The arm 40 is also connected to the piston members 42, 43 of a dashpot, the cylinder of which is connected with the valve chamber by passages 46, 47. The partition wall of the dashpot is furnished with an adjustable leak 48. The pipes 38, 39 leading to the motor connect with a casing furnished with relief valves loaded by springs which valves under excessive pressures are displaced to byepass the pressure liquid.