Patent GB-517051-A (GB)
Title: A new and improved train token machine for the control of trains and like vehicles between stations
IPC: B61L23/24
Filed: 1938-10-27
Abstract: 517,051. Railway token systems. SCHOOR, M. C. VAN Oct. 27, 1938, No. 31080. Convention date, Nov. 8; 1937. [Class 105] A token system for controlling traffic on railways comprises at each station a combined absolute and permissive token instrument controlled by direct current devices in combination with a crossing token instrument controlled by alternating currrent devices which are all interlocked so that only one system of working is possible at a time. The permissive working may use distinctive tokens. The crossing token 'instrument allows crossing working on the permissive system. In the instrument shown in Fig. 1 the same tokens are used for the absolute and permissive working. This instrument comprises a receptacle 5 into which a token is placed from the instrument magazine, the token displacing a piece 7 which displaces a locking key 10 from a keyway in a fixed part whereby a barrel member 9 can be rotated on rotating the receptacle 5. The barrel 9 is provided with an interior bolt 25 having a partial peripheral screw thread which in the position shown lies above an unthreaded portion of the bore in the barrel so that the barrel and bolt are thus compelled to rotate as a whole. The bolt has a key pin 29 sliding in a keyway in a locking drum 32, so that this drum and the bolt always rotate together. The drum ends have oppositely arranged detent teeth which co-operate with pawls 49, 50 actuated by the armature 51 of a polarized electromagnet by which the control from the other station is effected; the drum also shifts from side to side a cradle 55 operating the usual commutator switch. When the instruments at the two stations are in phase a current polarity can be sent to operate the pawl 50 so that the drum is released for clockwise rotation whereby the receptacle 5 with barrel 9 and bolt 25 can be rotated 180‹ to bring the receptacle into a position allowing the token to be taken out. The instruments are now out of phase and a further token cannot be taken out until the first token is inserted in the instrument at one or other station. For permissive working from A to B the operator at A sends an in-phase current to allow the operator at B to take out a token. The operator at .B inserts this token in a permissive receptacle 13 which is then tilted downwards so that an aperture 22 in an interlocking quadrant piece 18, Fig. 20, moves into a position allowing the bolt 25 to be pulled axially to the left in Fig. 1. The operator at A sends current which is now out of phase and so lifts pawl 49 to allow the operator at.B to rotate the drum 32 anticlockwise; by pushing in and turning a dog clutch 36 the bolt 25 is rotated (being now above a threaded portion of the bore) but the barrel 9 is prevented from rotating by reason of the locking key 10. A locking tooth 21, dropped when a cam 20 on the interlocking quadrant 18 moves away from normal position, prevents the barrel from being rotated in a clockwise direction for the withdrawal of a token. The instruments are now in phase and the operator at B can send current to allow a token to be taken out at A. Succeeding tokens are taken out at A for permissive working, by sending in-phase current from B. Each token taken out renders the instruments out of phase so that before the next token can be taken out (which requires in-phase current from B) the operator at A must send out-of-phase current to B to allow the operator at B to rotate the drum 32 to give in-phase current. The bolt 25 travels axially for each token taken out in permissive working. As the trains reach station B the tokens are inserted in the receptacle 5 which is rotated to transfer them to the magazine; this rotation of the receptacle rotates the barrel 9 whereby the bolt is moved back a step for each permissive token inserted..When all the permissive tokens have been inserted at B the thread of the bolt 25 is free of the barrel thread and the bolt can be pushed to the right whereby the interlocking quadrant 18 and permissive receptacle 13 can be restored to normal position and the token therein replaced in the receptacle 5 and transferred to the magazine, this action restoring the instruments to normal and in the in-phase condition. For cross-working the operator at B sends inphase current to allow the operator at A to take out a token and insert it in the permissive receptacle 13 which, however, is now rotated upwardly and allows a gravity lever (not shown) to move out of locking engagement with a crossing token receptacle 69, Fig. 41, which on receipt of an alternating current from B can then be turned to the " open " position illustrated to allow withdrawal of the crossing token which may include permissive crossing tokens. With the receptable 69 at A in the " open position alternating current can be sent to B to release the crossing token receptacle at station B. When the trains have crossed, exchanged tokens, and proceeded, the tokens at station B are inserted in the crossing token receptacle 69; such insertion removes a lock bar 72 from a notch 73 whereby the receptacle can be moved to the " closed " position and, when in this position, an alternating current can be sent to A to remove a lock on the crossing token receptacle at A which is then moved to the " closed" position. If tokens accumulate at one station they can be transferred from the magazine to a portable carrier and placed in the magazine at the other station. The carrier is locked to the magazine during the transfer, Figs. 33-39 (not shown). The system is adapted for unattended working of the absolute token system. The driver of. a train at station A transmits a current to B whereby a clockwork switch causes a current to be transmitted from B to A for releasing a token, Fig. 51 (not shown). If distinctive tokens are used for permissive working a blocking piece must be changed over to open the permissive token magazine and close the absolute token magazine. This requires an added voltage battery being inserted which is effected by the depression of the receptacle 13 at station B. Such action frees the blocking piece at station A and after changing the blocking piece .over the operator at A can send on added voltage current to B to free the blocking piece at B which has to be changed over to allow the bolt 25 to be operated in the permissive working, Figs. 43-50 (not shown). The polarity of the'current may be shown by neon lamps provided with designs such as a .cross or ring. The locking drum 32 has auxiliary detent teeth whereby the drum cannot be turned back if it fails to be.locked at the 180 degree position. The pawls 49, 50 have pivoted pieces 53 whereby the main portion of the pawl remains in contact with the armature 51 and so prevents chattering of the armature by alternating current if the pawls were at half-cock.