Patent GB-489138-A (GB)
Title: Improvements relating to train describer systems for railways
IPC: B61L25/04
Filed: 1937-07-22
Abstract: 489,138. Automatic train - describer system ; electric signalling systems. GENERAL RAILWAY SIGNAL CO. July 22, 1937, No..20349.. Convention date, July 23, 1936. [Class 105] [Also in Group XXXVIII] As each train passes a track location a train description is transmitted, either manually by a wayside operator or automatically by the train itself through the intermediary of cooperating train and track devices, to a control cabin where the indication is given under the control of a stepping relay chain V1 ... V4 also operated by the above-mentioned manual or automatic action. The stepping relay chain V1 ... V4 operates a series of relay groups A1, Bl, C1.. Dl ... A4, B4. C4, D4 by which descriptions of successive trains are stored and certain of them (for instance, the first two descriptions) are shown on an indicator. On cancellation of the first description, either manually or by the train passing a second track location, the descriptions next in order of storage are brought forward on to the indicator ; this is effected by a further stepping relay chain K1 ... K4, which returns the contemporary leading energized relay of the first chain V1 ... V4 to its unoperated condition. The transmission of the train descriptions to the cabins is effected over multi-line wires or by code over a pair of line wires. One form of train and track apparatus is shown in Fig. 1, and the corresponding cabin apparatus is shown in Figs. 2, 2A, 2B. A token key E carried on and identifying the train controls appropriate contacts 7 whereby certain of the locomotive inductor cores CA ... CD are rendered effective to react on the track cores TA ... TD. The token key E is inserted in an appropriate socket according as the locomotive or the tender is first and thus ensures that the same conditions are set up in the track apparatus. The track cores lie in tuned circuits and on passage of the train certain of these become in effect de-tuned with the result that certain ones of a set of stick relavs RA ... RD are dropped. These relays were all picked up by a circuit over contacts 17, 16 when the train dropped a track relay IT, but this circuit is opened shortly afterwards when the slow repeater relay 1TP drops. The energizing circuit for the tuned circuits is also closed at contact 11 by the dropping of the track relay. Those stick relays RA ... RD which remain up apply energy to certain of the transmission lines LA ... LD whereby cabin repeater relays RAP ... RDP, Fig. 2, are energized. A train description having thus been transmitted a, relay SL is energized to pick up the first chain relay V1 over front contact 19 of the relay SL, back contact 20 of a half-step relay VPV, and back contacts 21, 22 of the counting relays V4, V2. After the train has thus transmitted its description by dropping the track relay 1T it shortly afterwards drops a track relay 2T, a back contact 36 of which causes the energization of an execution relay EX. A front contact 37 of this relay EX in conjunction with front contacts 38 ... 41 of such of the repeater relays RAP ... RDP as are energized applies energy to certain of the bus wires BA ... BD whereby certain of a set of relays A1 ... D1 are picked up over front contacts of the chain relay V1. For example, the relay A1 is picked up from the bus wire BA over back contacts 43, 44, 45 of relays V4, V3, V2 and front contact 46, of the relay VI. The relay A1 then sticks over its own contact 47 and a back contact 49 of a relay K1. Relay A1 being energized a lamp 1 in an indicator panel 1W is lit by a circuit from positive over back contacts 58, 57, 56, 55 of relays K4, K3, K2, K1 and front contact 50 of the relay A1. Thus the first train description is displayed on the indicator panel 1W by the lighting of certain of the lamps 1 ... 4. A second train passing the track location will similarly transmit its description to the relays RAP .... RDP and the consequent energization of relay SL will pick up the second chain relay V2 by a circuit from positive over front contact 19 of the relay SL, front contact 20 of the halfstep relay VPV (energized as described below), back contact 30 of relay V3, front contact 31 of relay V1, to the winding of relay V2. Relay V2 then sticks by a circuit over a back contact of a relay K2. When the execution relay EX is energized certain of the relays A2 ... D2 are picked up similarly to the relays A1 ... D1, but over front contacts of the relay V2. These relays A2 ... D2 then light appropriate lamps in a second indicator panel 2W ; for instance, the lamp 1 of such second panel is energized by a circuit from positive over back contacts 68, 67, 66, 65 of the relays K4, K3, K2, K1 and a front contact of the relay A2. Referring back to the half-step relay VPV, this relay was picked up when the relay SL dropped after the first transmission, the circuit being from positive over back contact 25 of the relay SL, back contacts 26, 27, 28 of the relays V4, V3, V2 and front contact 29 of the relay VI. At the end of the second transmission, this relay VPV is dropped, since the contact 28 of the relay V2 is then open. The half-step relay changes its condition after each transmission. A third train will similarly energize certain of relays A3 ... D3, but no indicator panel is lit. When, however, the relay K1 is energized either manually by the supervisor in the cabin depressing a push CRK or by the first train passing a second track location and dropping a track relay 3T, the description of the first train is cancelled while the description of the second train is transerred to the panel 1W and the third train description becomes displayed on the panel 2W. The relay K1 by the opening of its back contact 49 drops the group of relays A1 ... D1 and by the lifting of its contacts such as 53, 65 transfers the application of. potential to the front contacts of the relay groups A2 ... D2, A3 ... D3 whereby these groups now control the indicator panels 1W, 2W. The first chain relay V1 is dropped by the opening of back contact 24 of the relay K1. Successive departures of the trains actuate the relays K1 ... K4 in a manner similar to that of the relays V1 ... V4. The track core circuits may be non-resonant and arranged so that the action of the locomotive apparatus picks up the relay RA ... RD. Fig. 9 shows an arrangement in which a transverse-core winding 142 on the locomotive acts as a transformer secondary to energize longitudinal core windings CA, CB also on the locomotive which in turn energize track windings TA, TB for the relays RA, RB. Instead of the multi-line transmission to the cabin, an electric-code transmission over two line wires may be employed. As shown in Figs. 4, 4A, the track apparatus comprising the relays 2T, RA ... RD when actuated by the train energizes a starting relay STR whereby a polarity code transmission is given with the polarity of the steps determined by the state of the relays RA ... RD through the intermediary of relays PC, NC. The coding apparatus comprises a relay chain V1 ... V3 to give the successive steps. At the cabin the successive steps operate a relay chain V1<1> . . . V3<1> and if of positive polarity the line relay F1 places its contact 71 to the right thereby to pick up the repeater relays RAP ... RDP. These relays then control the cabin apparatus in the same manner as the similar relays in Fig. 2 ; the contacts 419, 425 of the cabin chain relay V1<1>, Fig. 4A, serve in place of the contacts 19, 25 of the relay SL of Fig. 2.