GB807300A - Shaft positioning control mechanism - Google Patents

Abstract

807,300. Stopping shafts in predetermined positions. COLLINS RADIO CO. March 25, 1957 [July 19, 1956], No. 9759/57. Class 80 (2). In a shaft positioning mechanism, one of a plurality of seeking switches, having a number of positions equal to the desired parts of revolution of the shaft, is directly coupled to the shaft, and the remainder of the plurality are coupled to the shaft in the ratio of the number of positions to a prime number and have a number of positions equal to the prime number. A driving motor 20 drives a common shaft 27 through a torque limiting coupling 21, the shaft 27 carrying rigid therewith a stop wheel 22 having ten equally spaced notches 23, the rotor 29 of a ten-position seeking switch 30, and a gear 31. The shaft 27 drives the driven shaft 13 through a gear-box 28. The gear 31 meshes with a. gear 42 on the shaft of a second seeking switch 40 having a prime number of positions, i.e. eleven, the ratio of the gears 31, 42 being ten to eleven. The seeking switches 30, 40 are connected electrically by a plurality of wires such as 17, 18 in a multi-core cable 11 and a common wire 16 with selecting switches 50, 60 having ten and eleven positions respectively and being geared together by gears 57, 58 in the ratio of ten to eleven. The notched wheel 22 is engaged by a pawl 24 retracted by a solenoid 26 to close a motor switch 25 when current passes by virtue of rotation of one or more of the selecting switches. The motor continues to be energized through the switch 25 until both seeking switches 30 and 40 have attained an open circuit position corresponding to the setting of the selector switches 50, 60. The selector switches 50, 60 are mounted in a remote control box 12 and are connected by gearing such that the reference dial 68 of the switch 60 rotates eleven tenths of a revolution for every complete revolution of the tenths switch knob 55. The twenty-two wires in cable 11 may be reduced in number in the manner described in Specification 498,062, [Group XXXIX].