GB371964A - Improvements in or relating to electric signalling systems - Google Patents

Abstract

371,964. Electric signalling systems. STANDARD TELEPHONES & CABLES, Ltd. and GRIFFITHS, J. B., Columbia House, Aldwych, London. Feb. 5, 1931, No. 3654. [Class 40 (i).] In a train indicator system in which designations are stored on registers and shown in a predetermined order, when the first indication is cancelled the indications stored on the registers are transferred in turn to the preceding registers under control of a common rotary switch. All indications are extinguished during the transfer process. An indication on a particular register can be cancelled and replaced without affecting the setting of the remaining registers. The system described employs direct manual control of the setting, but this can be replaced by a code signalling system of the type described in Specification 366,919. If the designation on the first indicator is to be 2, key 2 is depressed and A2 pulls up and locks, completing circuits for lamp LA2. Relay S1 operates and locks, transferring the control circuits to the second register. If the next indication is to be 3, key 3 is operated and B3 pulls up, lighting LB3 and energizing S2. Similarly the 3rd, 4th, and 5th indications are stored on relay groups C, D, and E respectively and control lamp groups LC, LD, LE. When a train leaves the station track contacts RC1 operate and K pulls up. Clutch C operates and locks the cams to a rotating shaft. As the cams move C locks over CH and the circuits for all lamps are broken over BS. K, which locked to RL, releases. At the first step off normal the circuit of the operated A relay is broken over AL and the relay releases, S1 being held over AB. At the second step AT completes a circuit for the operated B relay to energize the relative A relay, which locks, and at the third step the operated B relay falls away. Similarly the remaining registers transfer their indications in turn to the next preceding register. When one revolution of the switch has been made C releases and BS completes the circuits for the indicator lamps. Another designation can then be set up on the final register. Should it be required to cancel and replace an indication the relative key CK, e.g. CKC, is operated. The energized C relay releases and S3 falls away. A next indication set up is thus registered on the C relay group, the other register groups being unaffected.