Patent GB-331046-A (GB)
Title: Improvements relating to token instruments for single line railway systems
IPC: B61L23/24
Filed: 1929-05-10
Abstract: 331,046. Tyer & Co., Ltd., Leake, F. W., and King, V. S. May 10, 1929. Staff, tablet, and ticket systems.-A threeposition indicator D of a token instrument is locked by an electromagnet but with an allowance for limited angular movement to effect circuit changes, the indicator being fitted with contact springs to engage segments of a selector switch J, and with a commutator disc K to send normal or reverse line currents to the other end of the section on depression of a push H. To despatch a train from a station X to a station Y a normal current is transmitted from a station X to operate a polarized relay M at station Y, the circuit being battery I, wires 1, 2, over segment kb of the commutator disc K, wire 5, to earth, and at station Y over wire 6 to polarized relay M, wire 7, contact springs 8, 9, galvanometer L, wire 10 to line, and so back to station X, wire 10, galvanometer L, spring contact 9, segments k<c>, ka of commutator disc K (which is in depressed position) and wire 12 to the other pole of the battery. At station Y this action rings a bell 17 and energizes an electromagnet N to allow a contact arm 20 of an electro-mechanical relay to drop. by the movement of armature 14 of the polarized relay M to close a local circuit; a second armature 24 prepares a circuit over wire 19, the dropped arm 20, wire 22, wire 25 and segment 34 of the selector switch J so -that when the indicator is moved slightly the locking electromagnet F is energized over brushes 27, 35 to free the indicator which can then be moved to " train coming." The push H at station Y is now operated to send a reverse current to station X as the positive of battery I is connected through wire 2 and commutator segment k<c> to the line and so energizes polarized relay M at station X reversely to ring the bell 17 and prepare a circuit to selector switch segment 34<a> so that on moving the indicator slightly the lock F is released and the indicator can be moved to " train going." Both indicators are now in extreme positions and can only send reverse current or depression of their pushes H. The movement of the indicator at station X to the position " train going " permits of the withdrawal of a token through the opening cb as the blocking arm D<1> is moved. The indicators are re-set to normal by inserting at either station X or station Y a token in an opening c<a> and rotating it 90‹ tn actuate by means of a cam disc o, a lever p which lifts the dropped arm 20 on to a tooth 36 of the armature n of the electromagnet N. The arm 20 in its upper position closes a circuit to energize the locking electromagnet F over wire 19, arm 20, contact 37, wire 38, contacts 39, 40, wire 41 to outer segments of the selector switch J, brushes 35, 28 to the inner segment and wire 29. The indicator D can now be set to normal and on depressing the push H a normal current is sent to the other station energizing the polarized relay M whereby a circuit is made over the armature 24, wires 25, 26, selector switch segments, brushes 27, 28, wire 29 to release the locking magnet F; a normal current is then sent to cause the dropping of arm 20 at the station where the token is inserted.