Patent GB-829511-A (GB)
Title: Railway route-setting equipment
IPC: B61L19/06
Filed: 1957-12-06
Abstract: 829,511. Railway route-setting equipment. STANDARD TELEPHONES & CABLES Ltd. Dec. 6, 1957 [Dec. 8, 1956], No. 38025/57. Class 105. In a railway route-setting equipment for establishing a route through a network of track points and having a latch-type reservation relay U/R, e.g. having windings Ul, R1; U2, R2; &c., and a latch-type blocking relay V1, V2, &c. for each points, the relay U/R being operable to reserve the corresponding points for inclusion in a route and the blocking relay V being operable, after operation of the relay U/R to prevent the re-operation of this latter and the reservation of the points for more than one route at a time; the relays U/R required to establish a route are operable in response to the operation of entrance and exit route buttons S1, S2, &c., Z1, Z2, &c., respectively, for the required route and the relays V are operated over operated contacts of the U/R relays of the route in a circuit serving as a supply line for energizing the blocking relays V independently of each other. On operation of the entrance and exit buttons for a route, the U/R relays of all trailing points in one direction are operated and then the U/R relays of trailing points in the opposite direction, e.g. under the control of points selecting relays F1, F2, &c., associated with the respective points. The blocking control circuit for operating the V relays includes a test relay E operated by A.C. current and the relays V are controlled by a contact of the relay E so as only to be operated, by D.C., after relay E has operated. The network includes one or more crossings and a " U/R " relay and a " V " relay are associated with each crossing. As shown, to establish a route from signal S1, Fig. 1, to signal S4, the entrance push-button switch S1 and the exit button Z4 are operated. For this route points 1, 2 and 3 must be in their reverse positions. At f.c. (front contact) Z41, auxiliary test relay P4 is energized over b.c. (back contact) E42. At f.c. P41 selecting relay F3- (for points 3 in the reverse position) is picked up over b.c. S41 followed by selecting relay F1- for points 1, over f.c. F31-. At f.c. F11- the selecting relay F2- for points 2 is picked up over fc. S11 (of operated entrance button S1) and the relay F4- for the crossing 4 is also picked up over the same circuit, and winding U1 of latch-relay U1/R1 of points 1 is energized over f.c. F12-, b.c, R11 and V12 and operated. At f.c. F22- the winding U2 of latch relay U2/R2 of points 2 is energized over f.c. F31- and b.c. R21, V22 and at f.c. F21- the winding U3 of latch relay U3/R3 of points 3 is energized over f.c. F32-, b.c. R31 and V32, and relays U2/R2 and U3/R3 reverse. The blocking control circuit is now complete over condenser R1, b.c. E13, f.c. S12, b.c. P12, f.c. R12, R22, R32, f.c. P42, b.c. E41 and primary winding of transformer T4, to energize the operating winding the latch-type test relay E4 in the circuit of the secondary winding of transformer T4, to indicate that the selected blocking control circuit has been correctly switched through. At b.c. E41 the relay E4 is de-energized, and f.c. E41 D.C. is applied to the blocking control circuit over f.c. P42 to pick up the blocking relays V1, V2, V3 connected thereto. At b.c. E42 slow-releasing test relay P4 is de-energized but remains operated long enough for relays V1, V2, V3 to pick up. At the open b.c. E43 any accidental operation of entrance route button contact S42 is rendered ineffective and opens b.c. E42 renders contact Z41 ineffective if closed. If contact S12 is closed by operation of button S1 only A.C. flows through the blocking control circuit, which remains ineffective since relays V1-V4 respond only to D.C. Contact P41, being now open, allows the selecting relays F1- to F4- to be de-energized and drop off. At b.c. VII, V12, V21, V22, V31, V32, Fig. 2, the circuits for energizing the windings of the reservation relays U1/R1, U2/R2 and U3/R3 are interrupted and further operation of these relays prevented. Supposing now the entranceexit buttons S3, Z1 be operated for a conflicting route, relay P1 and successively selecting relays F2-, F4- and F1+ are operated. Relay U1/R1, however, cannot now be operated because contacts V11 and V12 are open. If buttons S4 and Z1 be operated for the reverse route, the open contact E43, Fig. 3, prevents the application of A.C. to the blocking control circuit, so that relay E1 cannot be energized. In a modification, the U/R relays do the work of the selecting relays F which are thus omitted from the circuits. As soon as the relays U/R and V for the route desired have been operated, the points 1-3 are thrown manually or automatically independently of each other into the reverse position by means of a points position changer, with protection against re-energization after it has operated to set up the route. An alternative circuit for operating the U/R relays taking into consideration the individual throwing of the points is also described.