GB164831A - Improvements in and connected with electrical signalling systems - Google Patents

Abstract

164,831. Sterling Telephone & Electric Co., Ltd., Bell, F. G., and Davey. W. C. March 12, 1920. Addition to 106,706. Order apparatus; systems of wiring indicators. -Comprises modifications of the system described in the parent Specification for exhibiting simultaneously at a plurality of receiving stations in a factory or the like a signal, such as a combination of coloured lamps, for summoning to the telephone or elsewhere a person to whom that combination is particular. According to the present invention, a single group of selecting relays, such as Rr, Rb, Rg, controls the lamps at several neighbouring stations. In order to prevent deterioration of the relay-contacts due to interruption of heavy lighting-currents, such currents are additionally broken at the operator's station bv a suitable switch. In the form shown in Fig. 1, the arm a of the operator's switch 5 closes the following circuits which are energized in parallel by the battery 6: (1) A circuit containing contacts 12 operated by a pendulum 13 and a winding 14 acting on the pendulum, which consequently closes intermittently the contacts 10; (2) a circuit containing the contacts 10 and a number of bells 23, one at each receiving station B; (3) a circuit containing one of the groups of selector-contacts (which are shown at 23 and are selectively operated by push-buttons), and the corresponding operative windings 1 of the relays Rr, Rb, Rg. The arms band c of the operator's switch 5 close a heavy-current circuit containing the hold-up windings 2 and contacts 4 of the selected relays, together with the corresponding selected lamps Lr, Lb, Lg, at the stations B. It follows that the lighting-current flowing through contacts 4 is not broken at the operator's switch 5. In a modification a single winding is substituted for the two windings 1 and 2 of each relay, the contacts 4 being arranged in parallel with the contacts 22.