Patent GB-571272-A (GB)
Title: Improvements relating to railway traffic controlling apparatus
IPC: B61L19/06
Filed: 1940-10-08
Abstract: 571,272. Railway traffic control systems. WESTINGHOUSE BRAKE & SIGNAL CO., Ltd. Oct. 8, 1940, No. 15000. Convention date, Jan. 19. [Class 105] , In a railway traffic control system of the entrance-exit button type, such as is described in Specifications Nos. 499,340 and 533,218, all the buttons are normally conditioned to act as entrance buttons and only when one of them has been operated to select an entrance are the buttons appropriate to routes having the selected entrance conditioned to act as exit buttons for such routes. This result is 'attained by the use of two directional relays, one for each direction of traffic, the energization of the appropriate relay conditioning the requisite exit buttons and lighting a corresponding direction indicator. Operation of the button appropriate to the selected exit effects setting up the desired route and extinguishes the direction indicator to show than any other non-conflicting route may be set up. Fig. 1A shows a track diagram indicator of the kind described in Specification 499,340 having illuminated strips corresponding with the track lay-out illustrated in Fig. 1D, the diagram also showing direction indications W, E with lamps WE, EE, Fig. 1B under control of the directional relays WR, ER respectively. The route-setting buttons, 2, 4, 6, 8, 10, 12 appropriately disposed on the diagram are of the kind having centrally located bulls-eyes for displaying the signal indications as in Specification 537,019. Three-position contact levers 1, 3, 5, 7, normally biased to mid position, are also provided for individual control of the track switches when necessary. Fig. 1B shows the circuits directly controlled by the push-buttons, therein designated 2P, 4P ... 12P, additional contacts of these buttons being shown in Fig. 1C, which also shows the routeestablishing circuits selectively completed by the exit buttons.. The track lay-out, Fig. 1 D, comprises two parallel main tracks, the upper normally for high-speed west bound traffic governed by main signal 10A, the lower normally for high-speed eastbound traffic governed by main signal 4A. These tracks are connected by cross-overs with pairs of switches 1A, 1B, 5A, 5B, 7A, 7B. The lower track is connected with a siding over switch 3. Signals 2, 4B, 6, 8, 10B, 12 govern slow-speed traffic. The tracks are divided into insulated sections IT, 5T, A1T, 7T, 3T, each having a current supply B and track relay 1TR., 5TR &c. with slow-acting repeater relays 1TP, 5TP &c. Each switch is operated by a switch machine, such as SM shown for operating switches, 1A, 1B to normal or reverse according to the left-hand or right-hand position of the contact of a corresponding polarized control relay 1WR. Each switch machine also controls a switch indicating relays such as 1WP (polarized) controlling a pair of repeating relays 1NWP, 1RWP, and the signals and track relays control switchlocking relays ILR, 3LR, 5LR, 7LR, Figs. 1C, 1D, in known manner. The signals are controlled by the usual HR relays, not shown here, but the Specification gives a circuit diagram with the contacts included in the circuits of all the HR relays for the signals shown. Each of the push-buttons, Fig. 1B, is associated with a corresponding entrance stick relay 2PS, 4PS &c. button 8P which occupies an intermediate position and is involved in " throughrouting," having additional auxiliary relays 8ES, 8XR. Source terminal B is connected over back contacts 13, 14 of relays ER, WR to normally closed back contacts of the buttons in succession, except for button 8P, in which the connection is to normally open contact 122, this button also having a second normally open contact 117 independently connected to terminal B. Each button also has a normally closed front contact connected to terminal B. This contact remains closed when the button is pushed to set up a route, but can be opened by pulling the button. The general operation of the system is as follows. When a selected entrance button is operated its normally .closed back contact is opened, and circuit is substituted from terminal B over a corresponding front contact through the corresponding PS relay and over an appropriate track relay contact (ITR, A1TR &c.) to source terminal C. Energization of the PS relay closes its stick circuit from terminal B over the normally closed front contact referred to above, so that the PS relay remains picked up when the button is released, and until the route becomes occupied or the button is pulled. Relay PS also closes a circuit from terminal B through the relay WR or ER according to the direction of the intended route. Energization of relay WR or ER closes a circuit through the corresponding lamp WE or- EE and opens contact 13 or 14 to disconnect the PS relay pick-up contacts of all the buttons from terminal B, so that, whilst one route is being set up, the setting up of another route cannot be initiated. Each route portion including a track switch has a route relay (NR or RR) corresponding to the switch position (normal or reverse) required for such route portion, these relays being shown in Fig. 1C. Thus for route 2-8 relay 1ANR is for operating switches, 1A, 1B to normal, for route 4-12 relay 1B-3NR for operating crossover 1 and switch 3 to normal and relay 5-7BNR for operating cross-overs 5, 7 to normal.. Contacts of appropriate route relays are included in the pick-up circuits of the PS relays, Fig. 1B, and 'also in the circuits of the switch-machine control relays such as 1WB, Fig. 1D. When an entrance relay PS becomes energized it connects terminal C of the source to one end of the circuit for each route relay for each route for which the energized PS relay indentifies the entrance. The energized directional relay controlled by the energized PS relay connects the terminal B to contacts of the push-buttons, Fig. 1C, for the exit ends of these routes, the buttons being thus conditioned to act as exit buttons. Operation of the selected exit button completes the circuit of the route relay for the portion of the selected route which is nearest its exit end, the remaining route relays for the selected route then picking up in succession. The last route relay to pick up releases the energized WR or ER relay to restore all buttons to normal and extinguish the lamp WE or EE. The selected route relays are held energized by the energized PS relay until the train enters the first section of the route or until the entrance button is pulled to cancel the route. The energized route relays open back contacts in the circuits of the route relays for all conflicting routes, control the track switches and signals shown in Fig. 1D, and also control the lights of the track diagram, Fig. 1A in the same way as the relays of similar designation described in Specification 499,340. The Specification traces in detail the circuits for setting up typical routes briefly indicated below. Pressing button 4P, Fig. 1B, closes front contact 16 to pick up relay 4PS, the stick circuit of which is closed by contact 21 from terminal B at the closed " pull-contact " 20. Contact 24 of relay 4PS closes the circuit of relay ER from terminal B over contacts 22, 23, 24, 25. Contact 26 of relay ER closes to light lamp EE, and its contact 13 opens to break the circuits of the button pick-up contacts. The circuit of relays WR, ER respectively include back contacts 91 of relay ER and back contact 25 of relay WR, so that those relays can only energize singly. Front contact 28 of relay ER, Fig. 1C, connects terminal B over back contact 27 of relay WR to contacts 29, 30, 31, 32 of buttons 8P, 10P, 12P, these buttons corresponding to exit ends of the routes for which relay 4PS identifies the entrance. Relay 4PS closes its contact 33 to connect terminal C to the circuit of relay 1RR for route 4-8, its contacts 34, 35, 36 to connect terminal C to the circuits of relay 1B-3NR, 5RR, 7ANR for route 4-10, via the preferred cross-over 5 reversed, contact 35 also connecting terminal C to the circuit of relay 5-7BNR which, with relay 1B-3NR governs route 4-12. If button 8P be now pressed, relay 1 RR picks up, over front contact 29 and the closed front contact 98 of relay 4PS, and opens its back contacts 99, 56 in the circuits of conflicting route relays 1ANR, 1B-3NR, opens back contact 23, Fig. 1B, releasing relay ER, and opens contact 100 in the circuit of relay 2PS. The stick circuit of relay 1RR is closed over its contact 101. Closing of relay 1RR contact 102, Fig. 1D, energizes right-hand winding of relay 1WR, its contact moving to the right to cause reverse movement of switches 1A, 1B. Relay 1WP reverses, relay 1RWP picks up, and a contact of this relay completes the circuit, not shown, of the signal relay 4BHR, over front contacts of relays 4PS, 1RWP, 1RR, and back contacts of relays 2PS, 1NWP, thus clearing signal 4B. If, instead of operating button 8P, button 12P be operated, relay 5-7BNR picks up, completing its own stick circuit at contact 47, and at its contact 48 completes the circuit of relay 1B-3NR. Closing of contact 65 of relay 1B-3NR, Fig. 1D, energizes left-hand winding of relay 1WR, thus causing switches 1A, 1B to be moved to normal. Similarly switches 5B, 7B are moved to normal, setting up route 4-12, relay 4AHR (not shown) being energized to clear signal 4A. Again, if exit button 70P be operated instead of buttons 8P or 12P, route 4-10 will be set up. In this case there are two possible routes, via cross-over 1 reversed, or cross-over 5 reversed. The relay circuits provided set up the preferred route via crossover 5 when button 10 is operated after initial operation of button 4, but the alternative route by cross-over 1 may be set up if desired, by operating buttons 4P, 8P to set up route 4-8, followed by operation of buttons SP, 10P to set up route 8-10. Similarly, although operation of buttons 4P, 12P sets up the straight route 4-12 with switches 1B, 5B, 7B at normal as pre