Patent GB-671789-A (GB)
Title: An improved electric remote control receiving apparatus
IPC: H02J13/00
Filed: 1950-05-26
Abstract: 671,789. Actuation of switches by remote control; electrically-released switches. LANDIS & GYR AKT.-GES. May 26, 1950. [May 30, 1949] No. 13362/50. Class 38 (v). A selector switching device or "receiver" for a remote control installation operating on the "impulse-interval" . system has an impulse receiving circuit and one or more electromagnetic switch units operating in conjunction with mechanism on a control shaft which is driven by a synchronous motor through a complete revolution on the receipt of a starting impulse, which may be an audio frequency impulse superimposed on the supply lines, the impulse receiving circuit being rendered inoperative after receipt of the starting impulse until the shaft has turned through a selected angle, the receipt of a further or "command" impulse then being effective to cause operation of the selected switch unit ; thereafter the impulse receiving circuit is again rendered ineffective until the rotation of the control shaft ceases. "Group" selection may be provided so that a second or "group" impulse must follow the starting impulse to enable the subsequent "command" impulse to be effective. In opera-' tion, an audio frequency impulse superimposed on the supply lines, a, b energizes a relay 2 through the normally closed contacts 3, 5 of a changeover switch unit 3 ... 5. The relay 2 momentarily closes its contacts 6 to cause the energization of an electromagnet 7 which attracts its armature 54, the armature turning a shaft 53 and with it, a lever 49 carrying a pin 48. The pin 48 engages and moves an arm 50 of a lever 39 pivoted at 40, so that an insulating pin 41 carried by the lever 39 is moved upwardly to enable contacts 9 to close and an arm 38 of the lever 39 disengages from a slot 29 in a "setting-to-zero" disc 28 on the control shaft 24. The synchronous motor 8 is energized when the contacts 9 close and through a friction spring coupling 16, 17, gears 15, 18, 22, 23 and Geneva movement 19 ... 21 drives the control shaft 24 in a step-by-step manner through a complete revolution, the engagement of the arm 38 with the periphery of the disc 28 preventing the return movement of the lever 39 to open the contacts 9 until the revolution of the shaft 24 has been completed. As the shaft 24 begins to turn, a member 56 falls from a cam 31 of a cam disc 30 causing a lever 55, 58 to turn in a clockwise direction, so that the pin 59 carried by it moves the contact spring 3 upwards to open the contacts 3, 5 to render the receiving relay circuit 1, 2 inoperative. As the shaft continues to turn, a cam 33 carried by a pre-set adjustable "group" selection disc 32 engages the member 56 so turning the lever 55, 58 and moving the spring contact 3 downwards momentarily reclosing the contacts 3, 5. The spring 5 is also moved downwards and is latched down by an arm 45 of a three-armed locking member 43, 45, 47 pivoted at 44. When the member 56 rides off the cam 33 it falls into a recess 36 which permits sufficient upward movement of the pin 59 on the lever 55, 58 for the pin 59 to close the contacts 3, 4. If now a "group" selection impulse is received, the relay 2 closes its contacts 6 to re-energize the coil 7 and the resulting movement of the lever 49 causes the pin 48 to engage the arm 47 of the locking member, so turning the member 45 to unlatch the contact-spring 5. This permits the subsequent energization of the receiving circuit, for otherwise, if no "group" impulse is received, the contact 3 cannot be moved sufficiently to engage the contact 5 and the contacts 3, are opened as soon as the member 56 rides out of the recess 36 on to the periphery of the discs, 30, 32. Thus if no group impulse is received, the receiving circuit cannot be reclosed and the device is inoperative until the completion of the revolution of the control shaft 24. Assuming that a group impulse had been received at the required instant, the contacts 3, 5 are reclosed when a cam 27 on a "switching" disc 25 moves a member 57 forming part of the lever 55, 58. The dwell of the cam 27 is such that the receiving circuit 1, 2, 3, 5 is complete during the two "steps" of the shaft 24 when a projection 26 on the disc 25 is above projections 67, 73 of members of the switch 13, which is disposed directly under the disc 25 and not displaced as shown. If a "command" impulse is received when the projection 26 is above the projection 73 the contacts 11, 12 of the switch 13, if closed, are opened. This is effected by the energization of the coil 7 attracting its armature 54 to cause the upward movement of a crank pin 51 interconnecting the lever 49 and a further lever 52. The pin 51 through a member 61, raises blade springs 62, 63 and an upwardlybiassed spring 71 tends to follow, but is prevented from doing so by the projection 73 abutting the projection 26. Thus the contacts 11, 12 are opened and a latch member 66 is raised by the spring 62 relatively to the spring 71 to enable a shoulder 72 to engage above the spring 71 so that when the command impulse ceases, the latch 66 maintains the contacts open. If, however, the contacts 11, 12 had been latched open and the "command" impulse was received by the device when the projection 26 was sabove the projection 67, the upward movement of the blade springs causes the latch 66 to turn as the projection 67 abuts the projection 26 so unlatching the contact blade 71 and allowing the contacts 11, 12 to close. The desired switching operation having been effected the member 57 falls from the cam 27 on to the periphery of the disc 25, the contacts 3, 5 are opened and the impulse receiving circuit rendered inoperative. At the end of the revolution of the shaft 24, the arm 38 re-enters the slot 29 and the lever 39 returns to its original position, opening the contacts 9 to stop the motor 8 and by means of an arm 42 engaging the arm 43 of the locking member to unlatch the contact 5 if it had remained latched due to the non- receipt of a "group" impulse. If the apparatus is to be used without "group" selection the discs 30, 32 are replaced by a single disc with the projection 31, and the locking member 43, 45, 47 and contact 4 are dispensed with. Specification 671,790 is referred to.