Patent GB-227175-A (GB)
Title: Improvements in electrical signalling systems
IPC: H04Q9/00
Filed: 1923-10-08
Abstract: 227,175. Western Electric Co., Ltd., (Western Electric Co., Inc.). Oct. 8, 1923. Selective distant control systems; tell-tale apparatus.-For signalling at a central station the positions of power switches located at remote stations, the switches control motordriven shafts which actuate impulse transmitters to select lamp indicators at the central station. The transmitters at anv one remote station are driven by a single shaft. As shown in Figs. and 2, a plurality of remote stations B, C is connected with a central station A. Power switches 8 - - 11 are located at each remote station, and the " on " and " off " positions of these switches are indicated at the central station A by pairs of red and green lamps 67, 68 - - 73, 74. When the switch 8 is closed, contacts 13, 15 are closed and a circuit is established from a battery 14, lines 98, 99, 102, line 103, and relays 57 100, 101, contacts 113, 15, to earth. The relay 57 is thus energized, and a circuit is completed from the battery 93 at the central station A, through lines 104, 105, 106, armature of relav 57, line 107, relay 59, line 7 and relay 87. The relay 59 is thus energized to start a motor 27, which drives a shaft 26 having gear wheels 28 frictionally mounted thereon and cams 49 - - 52. Rotation of the cam 49 closes the contacts 53 to energize a relay 34 over a circuit from the battery 14, lines 98, 99, 100, 101, contacts 13, 15, 102, line 103, contacts 53, relay 34, contacts 111 and earth. The relay attracts a latch 35 and releases a shaft 30, which is now driven through the gears 28, 29. Energization of the relay 34 also attracts two auxiliary armatures, and provides hold-on circuits for itself and the relay 59. Contacts 119 are also broken to prevent the operation of the mechanism associated with the switches 9. 10, 11 until after the signalling operation associated with the switch 8. The impulses, for signalling the position of the switch 8 are transmitted by a disc 47 over a circuit including the contacts 112, lines 105, 5, relay 85. line 6, and battery 14. The impulses are transferred from the relay 85, through a relay 84 to selectors 61, 62 of the type described in Specification 117,170. Each selector is associated with two power switches, and is adapted to select one of the relays in the pairs of relays 63 - - 66 and thereby illuminate one of the indicating lamps according to the characteristic signal received. After one-half of a revolution of the transmitter shaft 30, contacts 111 are broken by the disc 48 to de-energize the relay 34 and allow the latch 35 to stop the shaft. A disc 46 allows for engage,- ment of the contacts 124 in order to prepare the operating circuit for a signalling operation, when the switch 8 is again opened. The switches 8, 9 are both associated with the master relay 57, and the switches 10, 11 are associated with a relay 58 which functions in the same manner as the relay 57. When the station B is transmitting, the relay 59 attracts an armature 129 to prevent operation of stations such as C which are more distant from the central station. When, however, the station C is transmitting, relays 60 are energized to prevent operation of the. apparatus at stations nearer the central station. The power switches 8 - - 11 are operated from the central station A by impulse transmitters such as 88. Upon rotation of a transmitter, a relay 89 is energized over a circuit from earth, through the transmitter 88, contact 90 which remains closed during the rotation, line 91, relay 89, battery 92 to earth. The relav 89 thus attracts its armatures and connects the battery 93 to the lines 5, 6. During rotation, impulses are produced by the contact 94, and the consequent operation of the. relay 84 transmits impulses from the battery 93 over the lines 5. 6 to selectors which are similar to the selectors 61, 62.