Patent GB-451337-A (GB)
Title: Improvements in gyroscopic apparatus
IPC: G01C21/18
Filed: 1935-01-03
Abstract: 451,337. Automatic control systems. GRAY, A., and GRAY, E. R., [Executrices of GRAY, J. G.], 4, Hamilton Drive, Glasgow. Jan. 3, 1935, No. 25416/34. [Class 38 (iv)] [See also Groups XX and XXXVIII] The stabilizing-apparatus described in Specification 341,592, [Group XX], is modified by the provision of means whereby the axis of the precessing gyroscope 1 is maintained horizontal during turning of the supporting craft notwithstanding deviation from the horizontal of the pivot-axis 4-4. In the form shown in Fig. 1, the gyroscope 1 with horizontal spin axis is pivoted on vertical pivots 2 in the frame 3 and is centralized by springs 9. The frame 3 is neutrally mounted by normally horizontal pivots 4-4 in uprights 5 and is made pendulous by suspending from the gyro casing on pivots 8 aligned with the spin axis a pendulum 7 which notwithstanding inclination of the axis 4-4 applies during turning of the supporting craft a torque causing the gyro 1 to turn with the frame 3 and the spin axis to remain horizontal. A lever 15 mounted in pivots 16-16 parallel to the pivots 4-4 has on its upper side a groove in which a ball 19, Fig. 4, is guided by prongs 18 carried by an arm 17 extending from one of the pivots 2. When the spin axis is normal to the frame 3, the ball 19 lies over the pivots 16-16, but when the spin axis deviates from its normal position the ball 19 is moved from its central position and causes the lever 15 to rock and close one or other of the contacts 20, 20<1>. The latter control the operation of stabilizing solenoids 14 carried by an upright 5 and co-operating with an armature carried by an arm 12 fixed to one of the pivots 4. In a modification the solenoids 14 may be replaced by a pair of reversible motors mounted on the pendulum 7 and each driving a system of plane vanes under the control of the contacts 20, 201. The mass forming the pendulum 7 may be traversed by a screw so that its distance below the pivots 4-4 may be adjusted to correspond to the speed of the craft. An adjustable compensating weight is provided on the frame 3. The steersman may guide the craft in a straight course by reference to two lamps in parallel with the motors or solenoids 14. Push-button switches connected across the contacts 20, 20<1> are operated when it is desired to change course whereupon the motors or solenoids 14 cause the gyro 1 to precess and the appropriate lamp to be illuminated so that the steersman may turn the craft to make the frame 3 follow the gyro 1. In a further modification the supports for the pivots 4-4 are mounted on a vertical axle which may be turned by motors controlled by the contacts 20, 201. In a still further modification the frame 3 carrying the gyro 1, contact making system 15-19, pendulum 7, motors for driving the vanes, and a pendulous stabilizing gyroscope which is supported with its spin axis normally vertical on pivots parallel to the pivots 4-4, is pendulously mounted by horizontal pivots lying athwart the craft in a gimbal pivoted to the uprights 5 on the fore and aft pivots 4-4. In the form shown in Fig. 14, the frame 3 carries, in addition to the gyro 1, a training gyro 1<1> on horizontal pivots 50-50 parallel to the pivots 4-4. The training gyro 1<1>, when the craft turns, in addition to applying to the frame 3 through the restraining springs 51 a torque sufficient to cause the gyro 1 to precess and follow the frame, precesses on the pivots 50-50 and moves a contact arm 58 over studs 60. The latter control a number of electromagnets 54 spaced along a rod 53 fixed to one of the pivots 2 in a direction parallel to the spin axis of the gyro 1. Retained under each electromagnet 54 by prongs 57 is a steel ball 55 resting on a platform 56 secured to the frame 3. An electromagnet 54 at a distance from the axis 2-2 proportional to the rate of turning of the craft is energized and transfers a ball 55 from the platform 56 to the rod 53 where it exerts about the axis 2-2 when the axis 4-4 is inclined a torque sufficient to keep the spin axis of the gyro 1 horizontal. In a modification precession of the training gyroscope 1<1> causes a mass secured to the casing of the gyro 1 to be moved in a direction parallel to the spin axis whilst a similar compensating mass secured to the frame 3 is moved in the opposite direction. As shown in Fig. 21, the contact arm 65 fixed to the precession axis of the training gyroscope 1<1> moves over studs connected at equally spaced intervals to a resistance 69. The masses 73, 79, carried by the gyro 1 and frame 3 respectively have contacts 74, 80 each moving over a series of studs 70, 76 connected at equally spaced intervals to resistances 71, 77. The masses 73, 79 are threaded and traversed respectively by screws 72, 78 each driven by a pair of motors 75, 81. The resistances 69, 71, 77, are connected in parallel to a battery. Each of the contacts 74, 80 is connected through a relay 82 to the contact 65 and the two relays control respectively the operation of the motors 75 and 81. The frame 3 with the system shown in Fig. 14 or the modified system shown in Fig. 21 and a pendulous stabilizing gyro pivoted with normally vertical spin axis in the frame 3 on pivots parallel to the pivots 4-1 may be pivoted on horizontal transverse pivots in a gimbal ring which carries a compensating gyro with transverse spinning axis and is pivoted in the supports 5 on the fore-and-aft axis 4-4:. In a modification of the system shown in Fig. 21 the gyroscope 1<1> is separated from the frame 3 and the compensating mass 79 carried by the frame 3 is omitted so that the mass 73 during turning of the craft provides a torque about the axis 4-1 sufficient to cause the gyro 1 to precess and follow the frame as well as a torque about the axis 2-2 sufficient to keep the spin axis horizontal notwithstanding inclination of the axis 4-4. Solenoids mounted on the frame 3 and acting upon an armature fixed to the gyro casing 1 may be put in circuit with the contact making system 15-19 during turning of the craft in order to provide a correcting torque about the axis 2-2. Fig. 31 shows a relay by which the frame 3 may stabilize a platform. A motor 95 mounted on one of the supports 5 drives at uniform speed in opposite directions two drums 98. An arm 94 fixed to one of the pivots 4 is connected to the member 99 to be stabilized by two cords or the like 100 each of which passes one or more times round a drum 98. Normally the cords 100 are slipping on the drums 98 but when the arm 94 moves one cord 100 is tightened and the other slackened whereupon the member 99 is caused to follow the arm 94 by an amplified force derived from the frictional drive of the drum 98 on the tightened cord 100. In a modification the controlling arm 94 and controlled member 99 are replaced by pulleys and the two drums 98 by a single drum around which both lengths of cord pass. Fig. 34 shows a platform stabilized with respect to both pitching and rolling. The platform 102 is mounted by horizontal pivots 107 in a gimbal 106 which is attached to uprights 103 by pivots 101. A stabilizer A with its axis 4-4 athwart the craft is connected through a relay as shown in Fig. 31 to one pivot 101 and a second stabilizer B with its axis 4-4: fore and aft is mounted on the platform 102 and connected to one of the pivots 107 through another relay. Since the axis 4-4 of the stabilizer B is maintained horizontal by the stabilizer A the training gyroscope 1<1> may be fixed to the frame 3. The precessing gyroscope 1 of the stabilizer B may be prevented from making large excursions on the pivots 2 by an arm fixed to one of the pivots 2 and controlling through a small relay of the type shown in Fig. 31 an arm which is pivoted on the frame 3 and when rocked swings a mass laterally to cause a torque restoring the gyro 1 to the central position. The training gyroscope 11 is driven at a speed inversely proportional to the speed of the craft and its casing is pivoted in the frame 3 on an axis in line with the spin axis and is restrained by springs. When the speed of the craft, and therefore the gyro 1<1>. changes the casing is swung on its pivots by reaction forces and operates contacts. The latter control solenoids attached to the frame 3 of the stabilizer A and coacting with an armature on the gyro 1 of the stabilizer A, thus causing a torque about the axis 4-4 sufficient to counteract the effect of changes of speed on the pendulous frame 3 of the stabilizer A. Alternatvely the solenoids may swing a mass pivoted on the frame 3 into a lateral position where it will give rise to a compensating torque.