Patent GB-898804-A (GB)
Title: Improvements in and relating to gyroscopic control systems
Inventor: BOSCH MAURITS TEN
IPC: G01C19/38
Filed: 1958-07-29
Abstract: 898,804. Mechanical servomotors; reverse gear. TEN BOSCH Inc., M. July 29, 1958, No. 24358/58. Class 80 (2). [Also in Group XX] In a torque amplifier for a gyroscopic control system for a body in flight or other motion, rotation of a pilot shaft 94 axially moves through a screw and nut 98, 100, an output shaft 101 to engage a friction clutch driven disc 103 fixed thereto with either one of contrarotating clutch driving members 104, 105 geardriven by an electric motor E. As described in Specification 898,805 two gyroscopes, the control axes 80 of which are perpendicular to the longitudinal axis of motion of the controlled body and may be disposed at 90 degrees to each other, and the rotor axes of which are normally parallel to said longitudinal axis, provide directional control for yaw and pitch. Each gyroscope comprises a rotor F journalled in an inner gimbal G which is pivoted in an outer gimbal H by bearings arranged at 90 degrees to bearings 72 by which the outer gimbal is pivoted in a frame 10 mounted in the controlled body. The rotor F is driven by the motor E through a shaft 16, bevels 20, 35, a shaft 37 and a cardan shaft universally jointed at 45, 46. An insulated shoe 188, supported by a link 212 and an arm 217 of a shaft 218 of the other gyroscope carried in a frame bracket 220, and guided in a slot 187, carries, on a U-shaped spring 193, a contact button 195 normally riding on an insulating strip 196 extending diametrically across the top of an insulating disc 197 between two commutator segments 198. Each segment 198 electrically controls one of two torque motors W comprising electromagnetic friction clutches V having contrarotating driving members 172 gear-driven from the shaft 165 and driven members 236 fixed to pinions 175 meshing a gear sector 237 which together with a counterweight 238 is fixed to the outer gimbal H. The torque amplifier pilot shaft 94 carries a pinion 96 meshing a sector 95 fixed to the outer gimbal H. The output shaft 101 carries a pinion 114 meshing a wheel 115 on a shaft 145 which is connected through a helical spring 148 to a pinion 149 meshing a wheel 150 integral with the nut 100. The pinion 149 is secured to a disc 151 of a magnetic damper 152. A pinion 116 also secured to the shaft 145 meshes a wheel 117 which is journalled on the shaft 101 and has a screwed extension 126 threaded into a screwed recess 119 in the nut 100. Ball thrust bearing bearings K for the clutch driving members 104, 105 are loaded by coil springs, or, as shown, leaf springs 274. The output shaft 101 drives a shaft 256 through helical gears 252, 254 the tooth angle of which effects axial thrust augmenting clutch 103 engaging pressure and hence torque amplification. Deviation of the controlled body may be corrected through the shaft 255 and through a bevel gear 263 connected to the shaft 255 through bevels 258, 259 and a shaft 260. As described in Specification 898,805 a spring-loaded, inertia released, detent locking the gimbals is released as soon as the controlled body starts in motion. In operation, upon controlled body deviation two signals are transmitted, one from the outer gimbal H through the gearing 95, 96 to the pilot shaft 94 and the other through the commutator segments 198. Rotation of the shaft 94 effects engagement of the discs 103 with one or other of the members 104, 105 and rotation of the shafts 255 and 260 through the shaft 101 and the clutch pressure-augmenting helical gears 252, 254, follow-up action by the screwed extension 126 terminating shaft 101 rotation. Simultaneous with the shaft 101 rotation, the spring 144 is wound up against the magnetically damped disc 151. Subsequently the spring will unwind and rotate the nut 100 through the gears 149, 150 to axially move the shaft 101 in a direction opposite to that effected by the shaft 94, thereby declutching and engaging the disc 103 with the other of the members 104, 105 to effect reverse rotation of the shaft 101. This clutch reversal action by the damped spring 148 continues until there is final declutching. Upon controlled body deviation about the axis 80 the gyroscope tends to follow this deviation due to friction and precesses about an axis 90 degrees to the axis 80 thereby moving one of the commutator segments 198 under the contact button 195 and engaging one of the clutches V to apply torque to the outer gimbal and maintain the gyroscope in its original orientation.