Patent GB-496495-A (GB)
Title: Improvements in or relating to railway signal and/or points control equipment
IPC: B61L19/06
Filed: 1937-05-31
Abstract: 496,495. Route setting apparatus. STANDARD TELEPHONES & CABLES, Ltd., GRIFFITHS, J. B., and BROWN, A. May 31, 1937, No. 15091. [Class 105] The invention relates to apparatus wherein a multi-position switch device is used to set up any one of a group of conflicting routes, providing that no other multi-position switch device is in a position to set up a route conflicting with the route which it is desired to set up. Such an apparatus is described in Specification 3199/10, [Class 105]. The present invention provides the following improvements. The multi-position switch device can only move to the required position if another multi-position switch device is not in position to set up a conflicting route, and when it has moved to the required position the route cannot be set up unless the other switch is still in a non-conflicting position. The route cannot be set up unless the multi-position switch has stopped at a position corresponding with the operator's panel key. The operator's panel keys are always free to be moved from route-setting position but interlocking circuits prevent movement of the multi-position switch if wayside signal or track conditions are unfavourable. The multi-position switch cannot be stopped during its homing movement even if a further panel key has been operated. If a fault condition allows a second multiposition switch to move to a conflicting position the signal returns to danger. The setting up of the route is not initiated until the multiposition switch is at rest at the required position. Two multi-position switches which set up conflicting routes cannot be set in motion simultaneously. The multi-position switch must be in the home position before it can start towards the route-setting position. The operator's panel keys may be of the rotary spindle type having normal and route setting positions. The multi-position switch may be of the motor-driven type with a number of cams operating the contacts or may be of the multiple wiper type; in the subsequent description they will be described as sequence switches. Fig. 1 shows a track lay out and Fig. 2 shows some of the various routes which can be set up, these routes being allocated, as shown in the table, Fig. 3, to different positions of a number of sequence switches. Fig. 4 shows an interlocking table from which it will be seen that route 5 conflicts with routes 1, 3, 6, 8 ... 16, 20. Route 5 is allocated to position 1 of sequence switch 1 ; certain of these conflicting routes 6, 10- 14, 20 are allocated to other positions on the same sequence switch 1 and therefore interlocking is automatically effected since the switch can only be in one position at a time. Of the other conflicting routes, routes 1, 3 are allocated to sequence switch 3 at positions 1, 2, routes 8, 9 to sequence switch 4 at positions 1, 2, and routes 15, 16 to sequence switch 2 at positions 3, 4 ; accordingly interlocking must be provided to prevent the sequence switch 1 operating if another sequence switch such as 2, 3, or 4 has set up a conflicting route. The sequence switches are motor driven through an electric clutch and have cams to operate contacts at various positions ; for example in Fig. 6, a cam 1B (of sequence switch 1) is shown as having a lower left-hand contact which has the symbol 18 /2 denoting that it is closed continuously during the movement of the cam from position 18 to position 2 ; if the cam made contact at positions 18, 1 and 2, but not between such positions the symbol would be 18.1.2. To set up route 5 the signalman operates a panel key to close its reverse contact 5(R) thereby energizing the clutch magnet for sequence switch 1 ; the circuit is from battery feed Bl, over a contact 3F 3/18 (closed so long as cam F of sequence switch 3 is not in position 1 or 2 and thereby setting up a conflicting route), a similar contact 4F 3/18, a contact 2D 5/2 (closed so long as cam D of sequence switch 2 is not in positions 3 or 4 and thereby setting up a conflicting route), contact 5 (R), a contact 1B18 (closed by cam B of sequence switch 1 in home position 18), front contacts 1 of relays 1ZR, 2RC, 3RC, 4RC, winding of the clutch magnet 1R and winding of a motor-start relay MS to negative. The relays 2RC, 3RC, 4RC are deenergized (by clutch-controlled contacts) if their associated sequence switches are in motion and so would prevent the sequence switch 1 being operated if another sequence switch were in motion. The relay 1ZR has one winding energized over a contact 1H18 (sequence switch 1 at home position 18) and a second winding energized over its own front contact 2 from the clutch-magnet circuit. Thus the relay 1ZR is de-energized by the breaking of the clutch magnet circuit when the sequence switch 1 reaches the required position to set up the route ; the relay 1ZR by opening its contact 1 prevents the sequence switch 1 being operated to set up another route if the signalman attempts to do so without first having brought the sequence switch 1 to its home position 18. In the case of the route 5 (which requires sequence switch 1 to be in position 1) it will be seen that the above clutch feed circuit is opened as soon as the sequence switch 1 leaves the home position 18 but the movement to position 1 is completed through a contact closure by cam A of the sequence switch 1 at the point 1A1 .... 18. With the sequence switch 1 stopped at position 1 and corresponding with the key contact 5, a proving relay 1PR is energized by a circuit branching from key contact 5 (R) over contact 1 of camF of sequence switch 1, and a front contact 1 of a relay 1RC which is energized when the clutch magnet 1R is dead. If another route is now set up by operating a different sequence switch such as sequence switch 2 this latter may pass through positions such as 3, 4 which would de-energize the relay 1PR and so flash the signals to danger but to prevent such de-energization a byepass is provided over a front contact 1 of a relay 2RF which is energized so long as the clutch magnet for sequence switch 2 is energized. The proving relay 1PR being energized and the sequence switch 1 being at position 1 contacts are closed to effect the operation of the various points required in route 5. For instance the points 50 must be at reverse and to effect this a relay 50RLR, Fig. 8, is energized by a circuit from battery feed B6, over front contacts of track relays 3TR, 104TR, 103TR, front contact of a relay 53NLR(points 53 at normal), contacts 3K18, 5F18 (sequence switches 3 and 5 at the home position 18), back contact 3 of relay 50NLR (dropped by cam O of sequence switch 1 not being at positions 5/18 and by the opening of back contact 3 of proving relay 1PR when this was energized), contacts 9/7, 1 /4 of cam P of sequence switch 1, front contact 1 of relay 1PR, and neutral contact 50 (c) of a points lever (for individual operation of the points). The points 51 are similarly reversed by a relay 51RLR being energized over front contact 2 of the proving relay 1PR and contacts 3.5/1, 1.3 of cam R of sequence switch 1. The points are automatically restored to normal. For instance as soon as the sequence switch 1 moves away from positions 1/4 the relay 50RLR is dropped and the relay 50NLR is energized at contact 5/18 of cam O of the sequence switch 1 ; the track relays 3TR, 104TR, 103TR must of course be energized. The signal for route 5 is the shunting signal 5/6/7 and is operated by the energization of a relay 5/6/7 HR, Fig. 10, by a circuit from battery feed B13, over front contacts of relays 50RKR and 51RKR (checking that the points 50 and 51 are at reverse), a front contact of a relay 1QR (repeating the relay 1PR), and a contact of cam T of sequence switch 1 at position 1. In the case of the main line signals such as the signal 1 for route 1 (set up by sequence switch 3 at position 1) the circuit to the signal relay 1HR (Fig. 9) includes front contacts of relays 3SR 7SR in addition to contact 2 of the proving relay 3PR, contact 1 of cam O of sequence switch 3, and contacts 1 of relays 50NKR, 51NKR to verify the points 50, 51 at normal. The relay 3SR removes the locking on the route as soon as the associated track section TC3 has been occupied notwithstanding that the approach sections may be occupied. The relay 3SR, Fig. 11, is normally energized by a stick circuit including its own front contact 1, and front contact 5 of track relay 3TR; the relay 3SR drops on occupation and its pick up circuit is only closed when the sequence switches 1, 3 respectively are closing cam contacts N5/18, J18 so denoting that they have been moved off the positions setting up a route over track circuit 3. Returning now to the set up route 5 and assuming the signalman puts the route key back to normal the opening of contact 5 (R) will drop the proving relay 1PR and its repeat relay 1QR thereby dropping the signal relay 5/6/7HR. Accordingly a relay 1YR is picked up by a circuit from battery feed B1, over front contacts of relays 1RC, 105/106TR, 104TR, 5/6/7HR, contact 5 (N) and contact 1 of cam I of sequence switch 1 ; the relay 1YR then sticks over its own contact 2 and contact 1/17 of cam K of sequence switch 1 until this sequence switch is home. The sequence switch 1 is homed by a front contact 1 of the relay 1YR energizing the clutch magnet 1R and the motor-start relay MS.