GB286044A - Improvements in or relating to electrical systems of selection useful for indicating or signalling purposes - Google Patents

Abstract

286,044. General Electric Co., Ltd., and Cheel, H. G. Jan. 10, 1927. Indicating origin of call to servants and other attendants. -In an electric signalling system in which main indications are given at one station 17, and a subindication at another station 19 is given by a. relay when any of the indicators at the main station. is operated, a relav contact is closed when a predetermined number of main indicators are operated to limit the current in the relay winding. Fig. 2 shows the construction of the relay which is of the type described in Specification 159,675 and comprises windings 67, 68 provided with polar projections 105, 106, and armatures 69, 70, of which the former is less readily saturated and operates upon current from two or more of the lamps 39--42 flowing through the winding 68 to close contacts 72, placing winding 67 of heavier gauge wire in parallel with the winding 68. Fig. 1 shows the circuit arrangement for a number of cabins 144 - - 151 and main indicators 17, 18 associated with sub-indicators 19, 20 and a master indicator 21. The switches 1 - - 16 may be' of the type described in Specification 285,207, [Class 38 (v), Electric switches &c.], and the depression of the button 35 momentarily closes contact 36 to operate the bell 22 or the bell 24 according to the position of switch 88, but retains contacts 37, 38 closed to light the alley-way lamp 26 and one of the indicator lamps 39 - - 42 and to energize the relay 69. The closing of contacts 71 of relay 69 lights a lamp at the sub-indicator and energizes a similar relay 74 to give an indication at the master indicator 21. When the call is answered the switch is manipulated to open contacts 37, 38. The system may be duplicated to give two separate calls indicated by different coloured lamps at the indicators.