Patent GB-246478-A (GB)
Title: Improvements in electric signalling apparatus
IPC: H04L12/18
Filed: 1926-01-20
Abstract: 246,478. Favarger et Cie, Soc. Anon. Jan. 24, 1925, [Convention date]. Order apparatus.-Impulses are transmitted over two line wires bv a motor-actuated contact-mechanism until a step-by-step follow-up mechanism at the transmitter establishes contact with a manually selected contact. The impulses control a step-by-step switch at the receiver for selecting one of a number of indicators. One or more transmitters may control any number of receivers. As shown in Figs. 1 and 2, the transmitting apparatus comprises two selector mechanisms 4, 5 having contacts 19 - - 26 19<1> - - 261 connected by leads 40. The selector 4 has a wiper 28 which may be moved into contact with any one of the contacts 19 - - 26 by a manually operated crank 31 having a pointer 32 located opposite a dial 33. The selector 5 is of similar construction, but the wiper 28<1> is operated step-by-step by an electromagnet 36 to hunt for the selected contact of the selector 4 when impulses are being transmitted. The transmitting apparatus also comprises a motor operated contact mechanism 16, 17 and relays 6, 7. When the selectors 4, 5 are in their usual positions, i.e. when the wipers 28, 28<1> are in contact with corresponding contacts, the relay 6 is energized and the contacts 9, 10 are maintained open to break the circuit of the relay 7 and motor 8 respectively. When, however, the wiper is moved into any other position, the circuit oi the relay 6 is interrupted and the contacts 9, 10 are closed. The contact 10 closes the circuit of the motor 8 which rotates a pin wheel 18 and thereby opens the contact 16 and closes the contact 17 alternately. When the contact 17 is closed, a circuit is established for the relay 7 over the contacts 9 of the relay 6 and the relay 7 is energized to close its contacts 12, 13, 14 until the pin wheel 18 opens the contacts 16 to de-energize the relay 7. The contacts 12 establish a locking circuit for the relay 7 over the contacts 16 when the contacts 17 are opened. The contacts 13, 14 are connected in series with the line wires 1, 2 so that when operated an impulse is transmitted to the receiver magnet 42 and the magnet 36 of the follow-up mechanism of the transmitter. The receiver and the follow-up mechanism are thus operated step-by-step under the control of the contacts 16, 17 and the relay 7 until the wiper 28<1> co-operates with the contact which corresponds to the selected contact of the selector 4 and the relay 6 is energized to open the circuit of the motor 8. The electromagnet 42 of the receiver operates the wiper 43 of a series of contacts 45 which are connected to the indicator magnets 46. Any number of receivers may be connected in parallel across the line wires 1, 2. In a modification, several transmitters connected in parallel across the line wires 1, 2 may be provided. In this arrangement, each selector 4 is provided with an electromagnetic stepping mechanism in addition to the manual operating mechanism. When a selecting operation is performed at any one station, the energizing circuit of the stepping mechanism at that station is opened by additional contacts associated with the relay 6 and the selectors 4 at the remaining transmitting stations are operated synchronously.