Patent GB-587029-A (GB)
Title: Improvements in or relating to electric power follow-up systems or remote control systems
IPC: G05D3/12
Filed: 1939-07-19
Abstract: 587,029. Electric control systems. VICKERS-ARMSTRONGS, Ltd., and WATSON, J. P. July 19, 1939, No. 21027. [Class 40 (i)] A power follow-up system comprises a motor 1 with a winding 2 with tappings to segments of a commutator 3, with which co-operate three brushes 5 at 120 degrees which are connected to slip rings 6 and carried by the shaft of a two-pole indicator rotor. The slip-rings 6 are connected by leads 7 ... 9 to a switch comprising fixed contacts 10 ... 12 and movable contacts 13, 14 which are operated by a cam sector 19 of such configuration that two alternative positions of the contacts can be obtained for each direction of movement from the zero position shown. The cam sector is operable by a pin 26 engageable in a wrap-up cam mechanism such as is described in Specification 586,106 and comprising concentric circular grooves 27 in a disc 24 which grooves are interconnected by a slanting part in which the pin engages at zero position and a disc 25 having two complete-circular grooves. The disc 24 is driven from one side 23 of a differential gear, the other side 22 of which is connected to a control member 50, whereas the centre part 21 is geared to the rotor shaft. When 50 is operated, the cam sector 19 is displaced and produces a displacement of the motor-field, which displacement is followed by the rotor so that the cam sector is reset through the differential gear. In a modification, Fig. 2 (not shown), the brushes are mechanically displaced through the centre and a side member of a further differential gear, the other side of which is geared to the rotor shaft. Fig. 3 shows a system suitable for operating guns, searchlights, &c. in synchronism with a director. The input handle 58 drives an auxiliary motor 60 through a system similar to Fig. 1 and the motor drives a torque amplifier motor 61 by displacing its brushes 53 through a differential gear 62 and gearing 65 until sufficient torque is developed, whereupon the gun is driven through the shaft 66 and gearing 67. During normal operation of handle 58, with the gun lined up with its director, motors 60, 61, a transmitter motor 68 driven by 60 and synchronous motors 69, 71 driven respectively by 68, 61, all rotate at the same speed, and cam mechanism 24a, 25a and control switch 59a remain unaffected. When 58 is brought to rest, cam mechanism 24, 25 is restored by motors 68, 69 and differential gear 72. The parts 24a, 25a, 59a come into play if, due to overdriving of handle 58 and the resulting failure of motor 61 to keep in step, alignment between director and gun is lost. The tuning motor 77 is thereby brought into play and tends to drive the brushes 53 through gearing 78, 62, 65 and slipping clutch 63, the drive being effective to re-align the gun and director when the speed of handle 58 approaches normal. During the latter operation, the cam mechanism 24, 25 would restore first and stop motor 60; but a fly-wheel 64 continues to drive the brushes 53 and, along with the motor 77, control the deceleration of motor 61. If there is want of alignment when the current is switched on, cam mechanism 24, 25 which is already displaced, at once runs motor 60 up to full speed and the resulting angular displacement between motors 60, 61 operates the cam mechanism 24a; 25a and so the fly-wheel 64 and tuning motor 77 together move the brushes 53 until re-alignmenu has been effected. Specification 601,030 also is referred to.