GB872777A - - Google Patents

Abstract

872,777. Gyroscopic apparatus. FAIREY CO. Ltd. Nov. 20, 1957 [Nov. 26, 1956], No. 36151/56. Class 97(3) [Also in Group XXVIII] The torque to run a gyro rotor up to speed in a pre-determined number of revolutions is applied to the rotor shaft by a co-axial clutch member which is subsequently retracted out of the gimbal operating space. As shown, in a rate-of-turn indicator, rotor 70 is run up to speed by a pneumatic single stroke apparatus (see Group XXVIII) imparting rotation to shaft 85 and allowing compressed air to enter bore 109 to disengage dog-clutch 88, 90 by the co-action of plunger 107 with lever 104. Rotor 70 is mounted in gimbal ring 73 constrained by torsion bar 77 and frictional damping disc 82 in damping cup 83. The orientation and speed of the rotor 70 is sensed electrically by means of magnetic inserts 84 as in Specification 743,251. In another form, a free gyroscope is caged as in Specification 796,850 while it is run up to speed by the pneumatic motor and a spring is released to retract a telescopic shaft carrying a dogclutch, by a ball catch arrangement operated by a screw-threaded ring after a pre-determined number of revolutions. The dog-clutches in both forms may be re-engaged and the pneumatic motors returned to their starting positions by hand.