Patent GB-719133-A (GB)
Title: Improvements in or relating to railway signalling systems
Inventor: BROWN ANDREW
IPC: B61L19/06
Filed: 1951-02-14
Abstract: 719,133. Route-setting apparatus. STANDARD TELEPHONES & CABLES, Ltd. Feb. 8, 1952, [Feb. 14, 1951.] No. 3551/51. Class 105. A selected route consisting of a number of routes and/or partial routes, i.e. component track stretches of other routes, which include cross-overs, points and signals, is effected by a route selecting device such as a panel key, for selectively setting each of a plurality of route-setting media such as electromechanical sequence switches, each controlling its respective route component of a desired route set-up and means, such as relays responsive to the selecting key to render the sequence switches effective to set up the selected route. The key is adapted to control the release of the sequence switches which are also adapted to hold the route components as set, each being associated with its respective release means such as a relay which is included in an operational circuit -including contacts of detector means such as track relays associated with each route component to determine whether or not the route component is occupied and also including contacts which close dependent on the operation of the key to release position. The sequence switches are operated sequentially for setting up and releasing the routes, the operation being initiated by the proper positioning of the control key. The second and succeedipg sequence switch is made responsive to the indication that the preceding switch has reached its position to effect control of the associated route component and on contacts dependent on the operation of the panel route selecting key. On release of the route, the release of the release relays associated respectively with the second and succeeding sequence switches is made dependent on contacts of an indication device of the preceding switch that it has reached the position in which it releases the associated component. Fig. 1 shows a track layout comprising several routes and route components designated 3E5, 4E1, 5E1, 4W1, 4W2 and 9W2 (E indicating up-direction and W the down direction) from which the setting up of a route 4B3 extending from signal 4 on track A over points 6 to signal 35 on track B and consisting of partial routes 4B3, 4W1, 4W2, will be described, employing sequence switches of the kind described in Specification 526,829, [Group XXXIX], the control circuit being shown in Fig. 3 for setting up the first route component 4B3 and the driving and locking or holding circuit being shown in Fig. 4. Fig. 5 shows the control circuit of the sequence switch S.S.4 for setting up the second route component 4W1. Routes and/or route components which conflict in a desired route set-up are allocated position on the same sequence switch (S.S.). Thus all routes to which signal 4, Fig. 1, gives access are on the same S.S. and are thus mechanically interlocked. To set up the route 4B3, a key 4B3 represented by the broken line rectangle in Fig. 3 is operated to open its normal contacts N and close its reverse contacts R, thus completing an energizing circuit for the routesetting control relay 11ZRD over the cam operated contact EH-J-11 of S.S.11 which is closed only in the home position of the switch, and at contact 11ZRD, Fig. 4, closes a circuit for the switch drive control relay 11ZD which on operation causes the S.S.11 to drive from its home position to the position 5, thereon allotted to the route component 4B3. Relay 11ZRD provides a stick circuit for itself by a front contact in parallel with S.S.11 cam contact EH.J.11. An S.S. has a locking bar which locks it in position when stationary and when the S.S. is moved a lock magnet 11ZL withdraws the bar and when the S.S. stops the bar is reapplied. Relay 11ZD on operation, at a front contact completes the circuit of magnet 11ZL which withdraws the locking bar and completes at a front contact the energizing circuit of the clutch magnet 11Z for S.S.11 and the motor start relay MS. The S.S.11 drives so long as relay 11ZRD is picked up. On reaching position 5, the S.S.1 cam contact 4B3-END-11, Fig. 3, opens and causes relay 11ZRD to fall away followed by relays 11ZL, clutch magnet 11Z and relay MS to interrupt the switch drive. Each S.S. driving relay such as 11ZD breaks the circuits of all other ZD relays by series connected contacts in the + and - leads so that only one S.S. switch can drive at a time. In this position of S.S. 11 a circuit is completed for indication relay i iZC from + Battery over contacts R of the panel selecting key, and the cam contact 4B3-J-11 of S.S. 11 which is open in all positions of the switch except that allotted to route 4B3. This relay checks that the S.S. has stopped in the correct position. For every route on S.S.11 there is an operating circuit for relay 11ZC which is only closed when the switch has reached the position for the selected route such circuits are indicated by the multiple sign. The 11ZL back contact in these circuits proves that the locking magnet 11ZL, Fig. 4, has released and that S.S. 11 is locked. The closing of front contact 11ZC operates helping relays 11ZCP<SP>1</SP> and 11ZCP<SP>2</SP>. With S.S. i correctly operated the points 6, 12, Fig. 1, are set, i.e. points 6 reversed for crossing from line A to line B and points 12 normal. The driving relay 4ZRD of the S.S.4, Fig. 5, on which the next route component 4W1 appears is now operated over a circuit from Battery +, contacts including 11ZCP<SP>1</SP>, contact 11-J-4B3 of S.S.11 which is closed in the position 5 allocated to route 4B3, contact 4-J-EH of S.S.4 in its home position winding of relay 4ZRD to Battery -. The relay proyides a stick circuit for itself over contact 4ZRD which bridges contact 4-J-EH. Other operating circuits for 4ZRD are not shown but depend upon other routes utilizing the route component 4W1 and assigned to different S.S. positions. When S.S.4 has correctly operated in the same manner as S.S.11 it completes a circuit for driving relay 5ZRD (not shown) to operate S.S.5 on which the route component 4W2 appears. The track routes 4W1 and 4W2 are conditioned by setting the necessary points and clearing the signals by the signal control relay and is effected only if all the S.S.s needed for the selected route are in the correct positions and all the cross overs and points are correctly set as described, e.g. in Specification 737,558. On the train passing the signal 4, the signal automatically reverts to normal. The signal-man then restores the route selector key 4B3 to normal closing the contacts N and opening the contacts R, Fig. 3, thereby interrupting the circuit of indication relay 11ZC which releases followed by its helping relays 11ZCP<SP>1</SP> and 11ZCP<SP>2</SP>. The home driving relay 11ZND is then energized over back contact 11ZD and cam contact 4B3-J-11 of S.S.11 which in the set position of the switch is closed. The track relay closed front contacts 6BTR and 13TR indicate that tracks 6BT and 13T, Fig. 1, are not occupied. Front contact 4NPS indicates that the relay 4NPS (normal position stick relay of approach locking associated with signal No. 4) has re-operated and proves that there is no train approaching signal No. or that this signal has been at danger for long enough for a train approaching the signal to have come to rest or that a train has passed signal No. 4. Contacts 11ZCP<SP>1</SP> and 11ZCP<SP>2</SP> prove that their respective relays have released and that it is safe to allow relay 11ZND to operate. This relay sticks over its own contact and contacts of S.S.11 except the home contact H-11. Front contact 11ZND, Fig. 4, operates switch driving-relay 11ZD which causes S.S. 11 to drive to its 'home contact which is open thereby interrupting the stick circuit of relay 11ZND to arrest the movement of the S.S. 11. Release of relay 11ZCP<SP>1</SP>, Fig. 3, opens a contact in the circuit of indication relay 4ZC, Fig. 5, which releases followed by relay 4ZCP which prepares an energizing circuit for home driving relay 4ZND over contact 17TR which is closed if track 17T, Fig. 1, is unoccupied and over contact 4ZCP indicating that relay 4ZCP has released. On operation, relay 4ZND causes S.S.4 to drive home in the same manner as S.S.11 was driven home. Similarly S.S.5 (not shown) is caused to drive home when S.S.4 is at home and the track 25T is unoccupied by opening a contact of relay 4ZCP in the circuit of the release control relay 5ZC associated with the S.S.5. Specifications 496,495 and 557,131 also are referred to.