Patent GB-406995-A (GB)
Title: Improvements relating to the remote control of railway points and signals or the like
IPC: B61L7/08
Filed: 1932-09-06
Abstract: 406,995. Railway signalling systems. TOMLINSON, A. V., 65, Victoria Street, London.-(Compagnie Generale de Signalisation ; 23, Rue d'Athenes, Paris.) Sept. 6, 1932, No. 24872. [Class 105.] A railway signalling system in which signals and points such as at a number of field stations are controlled from a central despatch office over a transmission line but in which the signal or point control relays are not energized by their control current if local conditions are unfavourable is provided with storage relays, energized by such current, which energize the signal or points control relays when the local conditions again become favourable. The contacts 1, 2, 3 are respectively closed when codes for setting the points to normal, to reverse, and for clearing the signal are received. A relay D (not shown) lifts its contacts D1 .. D5 5 whenever a code is being received. Relays MP, MR (not shown) are energized respectively under predetermined conditions and if local conditions are favourable. When a code for setting the points to normal is received, current is supplied to points control relay NSR over contacts 1, D1, MP1, MR1, and WTR1, the last being closed if a fouling section repeater relay WTR is energized. A storage relay EAN is likewise energized over contacts 1, D1, MP1, wire 9, relay EAN, wire 8 and contact MTN1 , when the code ends the relay EAN sticks over back contact D3, back contact EAR2, front contact EAN1, wire 8, and contact MTN1, this circuit up to EAN1 also acting as a stick circuit feed for the relay NSR. The relay NSR energizes a relay NW to set the points to normal by the motor WM. Should local conditions be unfavourable the contact MR1 is open and the code will cause the energization only of the storage relay EAN so that not until conditions again become favourable will the relay NSR be energized, over the stick circuit feed to the relay EAN and the front contacts MR1, WTR1, to effect the points movement. Signal-clearing code picks up a storage relay ES which then sticks up, this stick circuit feed energizing a signal relay RHR or LHR according to which one of a normal or reverse points indication relay contact KRN1 or KRR1 is closed. The circuit to the signal relays RHR, LHR includes a time-element contact TE which closes a certain time after the local conditions relay MR is energized. If the relay MP is de-energized the code does not operate either the control relay or the storage relay but the back contact MP3 maintains the stick circuit for the storage and control relays already energized from a previous code. If the points fail to move over, a thermal relay MTN or MTR in due course opens a contact MTN1 or MTR1 whereby the storage relay such as EAN and in turn the associated control relay NSR are de-energized to prevent the continued supply of current to the motor WM. The fouling section repeater relay WTR may have a delayed pick up by providing a thermal relay in association therewith, Fig. 2 (not shown). An arrangement is also described in which the storage relays are energized only if the conditions prevent the control relays being energized.