Patent GB-623636-A (GB)
Title: Improvements in or relating to electrical remote-control method and system for electric circuit makers and breakers
IPC: H02J13/00
Filed: 1945-12-13
Abstract: 623,636. Electromagnetic switches. ZELLWEGER, Ltd. FACTORIES FOR APPARATUS AND MACHINES USTE R. Dec. 13, 1945, Nos. 33751, 33752 and 33754. Convention dates, Dec. 30, 1944, July 3, 1945, and Oct. 3, 1945. IClass 38(v)] [Also in Group XXXVIII] Low or high frequency signalling impulses are sent over power lines, and at the receiver are rectified and stored in a condenser which is discharged through a relay so that the signalling impulses need not be individually of such a magnitude as to actuate the relay. Systems employing ratchet devices.-In Fig. 1 the alternating current signalling impulse is applied over rectifier 4 and resistance 5 to charge condenser 6 which is periodically discharged through relay 15 by contact of relay 12; the actuation of relay 15 operates ratchet mechanism 17, 18, 20 to rotate cam 23 to operate contacts 25, 26 of the controlled or indicating apparatus; there may be more than one set of contacts 25, 26 spaced round cam 23; a cam disc 30, rotated by ratchet gear 18 alternately discharges condensers 37, 38 through relay 39 to short circuit condenser 6 for a short period after each actuation of relay 15 to avoid a single signalling impulse producing a second actuation of relay 15. Where there are a number of receiving stations and it is desired to bring them all to a standard or zero position, each station has a cam 41, Fig. 2, which at the zero position discharges condenser 45 through relay 46 to shortcircuit condenser 6 so that further impulses are ineffective to actuate relay 15; relay 46 is maintained operated for the period of transmission of sufficient pulses to bring all receivers to the zero position. Systems employing distributers.-At the transmitter, a distributer 69, Figs. 3a, 3b is traversed by a brush 70 to connect a source 51 of control signals to power lines 71 in accordance with the setting of switches 52-58, whose positions are to be repeated at the receiver. The received impulses charge a condenser 86 which is discharged through relay 91 by contacts 87 periodically actuated by a cam disc 89 continuously driven by a synchronous motor 101. The first impulse 72 is a starting signal and operates relay 91 to complete the circuit of relay 93 to actuate clutch 98 and connect cams 100, 99 to be driven by motor 101. Relay 93 holds on over contacts 95, 96, and connects relay 91 in a circuit controlled by contacts 102 instead of contacts 87. The movement of cam 100 then momentarily opens contacts 96 to de-energize relay 93, but the clutch 98 remains connected, being held by a latch, (not shown); cam 99 then opens contacts 102 allowing condenser 86 to be charged by any signalling pulse, so that when contacts 102 close relay 91 is operated to again actuate relay 93 to operate switch 112 in accordance with the setting of switch 52; this sequence of opening contacts 96, 102 is repeated until the cams 100, 99 have made one complete revolution when the clutch 98 is disengaged by means not shown. In a practical embodiment, relay 93, Figs. 4, 5 operates to slide a sleeve on shaft 124 so that the arm 145 depresses pin 125 to actuate the clutch 130 so that shaft 124 and its sleeve are rotated by synchronous motor 101; a latch 142 moves under the action of spring 144 to engage the head 146 of pin 125 and prevent it rising to disengage the clutch after arm 123 has moved away. Later operations of relay 93 occur as arm 123 is in position to operate similar mechanisms, e.g. 151, 153, 160 which actuate switches 112-118. It is demonstrated that the signalling pulses 76 must have a duration at least three times the period of charging the condenser, Fig. 6, not shown. In a further modification, the storage condenser 86 is discharged by a discharge lamp to actuate the relay instead of by mechanically operated contacts, Figs. 11-15, (not shown). System employing control signals of different frequency.-The condenser 86, Fig. 11, is charged by the control signal over tuned circuit 81, 82a, 82b, and discharges when it attains the striking voltage of lamp 195 to actuate relay 91 to operate mercury switch 211 and adjust the resonant frequency of circuit 81, 82 to receive the control signal of the second frequency for reversing switch 211. The Specification as open to inspection under Sect. 91 includes the use of direct current signalling impulses. In a further embodiment, each signal consists of a train of pulses selected by tuned circuit 32, 86, Fig. 7, (Cancelled); a discharge lamp 195 across inductance 82 protects the rectifier 85 and condenser 86 against unduly high voltage. The starting impulse energizes relay 91, Fig. 7, (Cancelled), to remove detent 172 and allow shaft 124 to move downwards under the action of spring 174, so that a pin 176 on pinion 175 presses pin 169 down to engage an aperture in disc 168 to couple shafts 181, 124 for rotation from synchronous motor 120. Before the arrival of the first signalling impulse, crown wheel 178 rides up on a cam 185 to raise shaft 124 so that detent engages collar 173 to hold the shaft in a raised position; a detent 167 prevents the uncoupling of shafts 170, 182. The arrival of a signal again actuates relay 91 to lower shaft 124 and thus bring arm 123 down so that it can engage spokes 187, Fig. 11, (Cancelled), and rotate cam 188 to actuate the switch 112. Before the arrival of a starting pulse, contacts 87 are actuated by a cam 89 three times per revolution of shaft, but after shafts 170 and 182 are coupled, cam 99 controls contacts 87 to close them once per revolution. When arm 123 has completed its cycle, an arm 184 disengages detent 167 to uncouple shafts 182, 170. This subject-matter does not appear in the Specification as accepted.