Patent GB-738800-A (GB)
Title: Improvements relating to systems for remote reading of the positions of sets of counters
IPC: G01D5/249
Filed: 1953-06-30
Abstract: 738,800. Electric selective signalling. KIENAST, A. June 30, 1953, No. 18179/53. Class 40 (1).  The reading of a meter which is registered on a plurality of denominational-digital-counter wheels is transmitted to a distant reading station by rotating a selector switch with each respective counter wheel, and scanning the switch positions of each selector in succession by voltage pulses over a constant speed scanning switch to produce a line current pulse from the remote reading station as each counter wheel setting is scanned, whereby the timing of the line current pulses is indicative of the meter reading. The readings of a group of meters may be transmitted over a single line by scanning them successively, and a plurality of meter groups may be " read," either successively, by using individual lines therefor, or selectively, by using individual starting signals of different frequencies therefor. Transmitter, Fig. 1. Each meter has selector switches 12b ... 12f arranged to be stepped in correspondence with the corresponding denominational jumper counter wheels w. In addition, a further similar selector switch 12a is preset to a position indicative of the meter. The contacts 1 ... 10 of the switches 12a ... 12f are scanned sequentially by the wiper of a scanning switch 11 in the positions 1-10, 12-21, 23-32, &c., the intervening contact positions 11, 22, 33, 44, 55, 66, 67, shown, being left blank. A scanning switch 11 together with associated switches 16, 17 are provided for each meter in a group of 100 meters. Each meter scanning switch 11 is driven by a synchronous motor 18. The switch 16 makes one step at the end of each revolution of scanner 11 and similarly switch 17 makes one step at each revolution of scanner 16. In this way the switch 11 is earthed over switches 16, 17 to scan its associated counter wheels only for one revolution in every hundred, the remaining meters of the groups being similarly scanned in succession during the remaining 99 revolutions. When a starting impulse of frequency f1 is received by each meter over line 10 from the reading station, a tuned relay 19 is operated, locks over a second winding fed through a rectifier 21 and switches on the synchronous motor 18, so that the scanning switches for all meters in a meter group start and run in synchronism. When all one hundred meters in the group have been scanned a stopping pulse of frequency f2 is received over line 10 from the reading station. It energizes a relay f2 at each meter which stops the motors of all the scanners in position 67 and de-energizes the starting relay 19. Reading station, Fig. 2. To initiate a reading, commencing with the meter group II, for example, a button B2 is momentarily operated to energize an associated selector relay 53 which locks and energizes a preparatory relay 56 for meter group III. A start button B0 is now momentarily closed to energize in turn a master relay 63 and a delayed action relay 69. Voltage at the starting frequency f from a generator 100 is now connected over scanning switches 34, 35, 36 and lines 101, 10, to start the meter scanning switches 11-16-17 at the meter group II selected by relay 53. At the same time a similar motor 18 at the reading station is started in the same way, by a relay 19, and drives scanning switches 34-35-36, 31-32-33, 30 in step with the corresponding scanning switches 11-16-17 at the meter station. In the successive positions of the scanning switch 30 voltage pulses at the reading frequency f3 are fed over a line 62 to line 10 and also to actuate a register 65 until the first marked contact (of selector switch 12a) is reached by the scanning switch 11 at the operative meter, whereupon the consequential current pulse (at the frequency f3) in line 10 operates a line relay 64 which in turn operates a delayed action relay 66 to break the pulsing circuit to the register 65 until the scanning switch 30- reaches the blank contact 11 to release the relay 66. Voltage pulses over switch 30 now again actuate the register 65 until the next marked contact (of selector switch 12b) is reached by the operative scanning switch 11, when pulsing of the register is stopped as before. In this way the register 65 is pulsed successively in accordance with the digits registered on the selector switches 12a . ... 12f, of each of the 100 meters of group II in turn, and in known manner, e.g. as in automatic telephony, registers or records the meter readings. When the scanning switches 31-32-33 reach the position shown, i.e. after reading of meter group II, voltage at the stopping frequency f2 is transmitted to line 101 to stop the scanning switches at meter group II at position 67 and similarly at the reading station. The stopping relay 20 at the reading station when operated also de-energizes the master relay 63, the delay relay 69, the meter group II selector relay 53, and disconnects the stopping pulse from line by releasing the start magnet 19. Before the delay relay 69 releases a pulse is sent over contacts 69b thereof to a timing device V which after a suitable delay energizes the meter group III selector switch 55, which energizes the master relay 63, releases the preparatory relay 56 and energizes the preparatory relay for meter group IV. The meters of group III are now read as above described and similarly for succeeding groups. To stop the reading at any particular group a switch R2, R3, &c., associated therewith is opened manually to prevent actuating of its preparatory relay so that reading ceases at completion of the preceding meter group. Modifications. The synchronous motors may be replaced by solenoid operated pawl and ratchet motors energized by A.C. pulses of another frequency f4 sent from the central station.