GB637415A - Improvements in electric receiving or switching devices for remote control installations - Google Patents

Abstract

637,415. Actuation of switches. LANDIS & GYR SOC. ANON. Dec. 3, 1947, No. 31961. Convention date, Dec. 10, 1946. [Class 38 (v)] A switching device or " receiver for a remote control installation has a synchronous motor, which when started by an audiofrequency responsive relay rotates a control shaft through one complete revolution, and through gearing loads a spring which when released by the action of the relay on the receipt of a second audio-frequency impulse, actuates a selected switch unit. An audiofrequency impulse superimposed on the lines a, b momentarily energizes relay coil 2 to turn the relay armature 3, which by means of a cam 5 closes contacts 7, 8 to energize the synchronous motor 12. The motor then drives the control shaft 15 through one revolution, the contacts 7, 8 being held closed by a cam disc 28. The motor also drives a shaft 19 through gears 16, 17, 18 and loads a spring 38 frictionally held between the gear 18 and a cam unit comprising a switch-actuating cam 36 and latching cams 34, 35, which are fixed together as a unit and free to rotate as a whole on the shaft 19. The cam unit is normally held stationary by a lobe or arm of one of the cams 34 or 35 abutting one of the downwardly projecting arms 32, 33 of leaf spring control levers 30, 31. These levers are held down in the latching position by abutments 26, 27 on them engaging the peripheries of control discs 20, 21 which are adjustably secured to the shaft 15. The discs 20, 21 have notches 24, 25 into which the abutments 26, 27 can move when the arms 28, 29 extending from them are free to move. Hence the first impulse received by the relay starts the motor and then to bring about a switching operation, a further impulse must be received by the relay at a timed interval afterwards, so that it may turn a cam 6 to remove a bar 9 out of the path of the arms 28, 29 as one of the notches 24 or 25 comes over its associated abutment 26 or 27. In the Figure the switch contacts 37 are closed, so that if the relay is energized when the notch 25 is over the abutment 27, the control lever 31 moves upwards disengaging the arm 33 from the cam 35, so that the cam unit is turned by the spring until an arm or lobe of the cam 34 abuts the arm 32 and the switch 37 is now held open by a lobe of the cam 36. Further actuation of the relay when the notch 24 is over the abutment 26 enables a further movement of the cam unit to occur to open the switch. Additional control discs 20, 21, levers 30, 31, cam units 34 ... 36 and springs 38 may be provided to control selectively additional switches 37. Specifications 494,792, [Group XXXVIII], 633,195 and 637,416 are referred to.