GB633195A - Improvements in electric selector switches or receiving devices for remote-control installations - Google Patents

Abstract

633,195. Actuation of switches; control of motors. LANDIS & GYR SOC. ANON. Sept. 15, 1947, No. 25223. Convention date, Sept. 9, 1946. [Classes 38 (iii) and 38 (v)] A switching device for a remote control installation has a synchronous motor which when started by a relay, rotates a shaft through one revolution, the shaft being also subjected to periodic axial movement during its rotation. This periodic axial movement is limited by a latching member which is moved aside on the further energization of the relay so permitting the full axial movement of the shaft to operate selected switch members. An audio-frequency voltage superimposed on the lines a, b momentarily energizes relay coil 2 to turn the relay armature 3, which closes contacts 9, 10 to energize the synchronous motor 11. The motor then drives the shaft 14, through gears 12, 13 through one revolution, the contacts 9, 10 being held closed by a cam 32, as the armature 3 returns to its original position. As the shaft 14 turns, a periodic axial motion is imparted to it by the engagement of a saw-toothed wheel 15 with a fixed abutment 20, the shaft 14 being biassed upwardly by a blade-spring 35. This axial movement is normally limited by a latchplate 4 attached to the armature 3, but on the energization of the relay coil 2 by a further impulse, the armature 3 moves the plate 4 aside so that the full axial movement, as determined by the depth of the teeth 19, may move an arm 22 a sufficient distance in a vertical plane to open or close the contacts 27, 30 of a selected switch unit 25, by lifting an insulating button 29 or 28. The audio-frequency impulse for this second energization of the relay is timed to occur at an instant when the shaft 14 is not bearing against the plate 4, that is, when the top of a tooth 19 is engaging the abutment 20. The switch arm 22 is adjustably attached to the shaft 14 by means of a slotted plate 21 fixed to the shaft 14, the arm 22 having a pin 23 engaging in one of the slots 24. This enables the position of the arm to be set so that when its upward movement occurs it is directly below one of the buttons 28, 29 of the switch units 25, which are arranged in a circle above the circular path in which the end of the arm 22 moves during its rotation with the shaft. The plate 21 may carry more than one arm 22 or alternatively several plates 21 may be used, each plate having an arm or arms co-operating with a bank of switch units 25. In a modification (Fig. 2, not shown), the teeth 19 of the wheel 15 may be of sinusoidal shape and engage with a roller carried by the fixed abutment. In a further modification (Fig. 3, not shown), the relay armature releases the contact 10, which is normally latched, to close the contacts 9, 10, and the cam 32 then moves the contact 9 to hold the contacts closed and at the same time relatch the contact 10 so that the contacts are opened when the cam has completed its revolution. Specification 494,792, [Group XXXVIII], is referred to.