Patent GB-826257-A (GB)
Title: Improvements in and relating to electrical remote control equipment
IPC: B66C13/23
Filed: 1956-09-21
Abstract: 826,257. Electric remote-control systems. MASCHINENFABRIK AUGSBURG NURNBERG A.G. Sept. 21, 1956 [Oct. 5, 1955; Nov. 28, 1955; July 19, 1956], No. 28970/56. Class 40 (1). Electrical remote control equipment for operating from a distance a plurality of appliances by means of control impulses transmitted to switch gears associated with the appliances by electromagnetic or air waves or over individual conductors such as over a sliding- contact line and earth is characterized in that the control impulses are transmitted by a distributer in such rapid succession to the controlled appliances that the operated switchgear cannot become disengaged. The arrangement is applicable to the control of cranes or conveyer belts. In a first embodiment, Fig. 1, the transmitter comprises a rotary contact arm 3 mounted on the shaft 1 of a two-pole synchronous motor 2, which arm sequentially connects contacts 4a-4# to the sliding-contact line 5. The control switches 6a-6# are set at neutral or connected with the contacts 7a-7# or 8a-8# which are commoned to the positive and negative poles respectively of a battery. The receiver comprises a rotary contact arm 13 mounted on the shaft 11 of a motor 12, which arm sequentially connects contacts 14a-14# to the current collector 15 located on the sliding-contact line 5, the contacts being connected to sluggish relays 16a-16# and 17a- 17# in parallel. If, when the distributers are rotating synchronously the switch 6a is set to the left, then on a circuit being made over the " a " contacts of the distributers, current will flow through a rectifier 19 to energize the relay 16a which holds during the subsequent distributer cycle. If the switch 6a is set to the right, the relay 17a will be energized. In a second embodiment (Fig. 2, not shown) the D.C. battery is replaced by an A.C. source of supply and rectifiers. In a third embodiment, Fig. 3, the transmitter and receiver each comprise three A.C. rotary synchro units 22-24, 25-27, one rotor lead of each unit being connected to a distributer contact, the fourth distributer contact being used to control synchronism and to switch on the receiver. The receiver switch gears are controlled by the units 25-27, each of which has one or more switching positions and a neutral position, the positions being controlled by control handles on the transmitter units. If the distributers run synchronously, then once each rotation a D.C. pulse is applied over the sliding contact line 37 to a relay 31 whose contact 32 remains closed to keep engaged the main contactor 34. If the rotation becomes asynchronous, however, the contact 32 opens and the receiver units 25-27 return to neutral under the action of return springs (not shown). Starting is effected by closing a switch 35 so that if three control levers 36 (only one shown) are at neutral, a relay 38 is energized to close its contact 39 and switch on the main transmitter contactor 40. Current also passes over the line 37 to energize a relay 45 which closes its contact 46 to switch on the receiver contactor 34 whereupon the transmitter and receiver commence to rotate. If synchronous rotation then continues the relay 31 will be energized as described above and the contact 42 opens to de-energize the relay 45. In a fourth embodiment, Fig. 4, phases R, S, T are connected as shown to the primaries of six transmitter transformers 51- 56 which have low inductive impedance so that alternating currents flow almost independently of the iron saturation, but the effective value of the currents used is so high that at maximum current the saturation limit is exceeded and no further alternating voltages are induced in the secondaries but short peak voltages occur so that within each cycle, at each phase, non- overlapping peak voltages are set up. Depending on the position at which the control switches 80-85 are set, voltage impulses pass over the two sliding-contact lines 72, 86 to current collectors and the receiver. The pulses pass to triodes 89-94 normally cut off by a battery 95 but opened when voltages pass from the secondaries of receiver transformers 60-65. The relays 96-101 thus respond in accordance with the setting of the control switches 80-85. In a fifth embodiment (Fig. 5, not shown) choke coils and rectifiers are employed instead of electronic valves. In further embodiments, transmission is effected by modulated radio waves (Figs. 6 and 7, not shown) by light-waves (Figs. 8 and 9, not shown) or by supersonic air waves (Figs. 10 and 11, not shown).