GB807917A - Control systems for aircraft - Google Patents

Abstract

807,917. Automatic control systems for aircraft. SPERRY GYROSCOPE CO. Ltd. July 12, 1956 [July 29, 1955], No. 21924/55. Addition to 803,572. Class 38 (4). [Also in Group XXIX and XXXIII] In a system, as in the parent Specification, in which a main hydraulic servomotor actuating a control surface of an aircraft may be automatically or manually controlled through an electrical control system or manually controlled through a mechanical control system, the arrangement for changing over from electrical control to mechanical control is modified. As shown, a differential linkage 310 responsive to the relative displacement of a manual controller and the main servomotor (not shown) positions a pilot valve 308 which controls the main servomotor through a solenoid-operated change-over valve 311 and a sleeve valve 301. Follow-up from valve 301 is provided through a lever 306 operating a sleeve 307 associated with pilot valve 308. Changeover to electrical control is effected by energizing solenoid-operated changeover valve 311 so that pilot valve 308 is no longer effective to control valve 301 and a pilot valve 302 operated by a device 208 responsive to electrical error signals produced manually or by attitude references on the aircraft, becomes effective to control the main servomotor through valves 311 and 301. To prevent a jolt when changing from electrical to mechanical control, valve 301 may be arranged to respond slowly to pilot valve 308. Specification 803,573, [Group XXIX], is referred to.