Patent GB-371055-A (GB)
Title: Improvements in or relating to apparatus for indicating the movement of railway trains or the like
IPC: B61L3/00
Filed: 1931-01-21
Abstract: 371,055. Electric signalling systems. LONDON ELECTRIC RAILWAY CO., 55, Broadway, Westminster, EVERY, W. S, Vanbrugh Cottage, Vanbrugh Road, Bedford Park, London, and DELL, R., Delslivere, Eton Avenue, Sudbury, Middlesex. Jan. 21, 1931, No. 2104. [Class 40 (i).] In a system for indicating at a station or signal box the movements of trains of the type wherein descriptions of successive trains are stored and transferred in succession to an indicator, the descriptions are stored at the receiver as perforations in a record strip and the strip is read section by section by a holereading device adapted to operate the indicator. Fig. 1 shows the transmitter and Fig. 2 the receiving equipment. Transmitting arrangements. The transmitter comprises two drums 10, 11 mounted on shafts 12, 13 and adapted to be set into selected positions by knobs 15, 16. The drum 10 has contacts 17 arranged so that any one of the fixed contacts 18 may be selected according to the destination of the train. The drum 11 is provided with adjustable contacts 21 and according to the setting of the drum a combination of contacts 20 is selected to determine the stations at which the train does not stop. The contacts 18, 20 are connected to the contacts 23 of a stepping switch 24 and the arrangement is such that when the wiper 25 engages a marked contact the polarity of impulses transmitted over the line wires 54, 55 is reversed to cause a punch at the receiver to perforate a strip. After the drums are set the shaft 12 is pushed inwardly provided a pin 32 is in alignment with a hole in disc 31, and a pawl 29 locks the drum in this position to prevent further setting during the transmission of information. Simultaneously the drum 11 is locked by a pin 36 which is operated from the shaft 12 through a collar 33 and rock shaft 35. Normally the collar 33 closes contacts 40 to energize a relay 42 but when the shaft is pushed inwardly to initiate transmission contacts 39 are closed to complete a circuit over lead 50 for stepping magnet 28 of the switch. Relay 42 remains energized over circuit including leads 44, 47 and contacts 45 closed in the normal position of the switch. The switch is thus stepped forward by the magnet 28 which controls contacts 28a, 28b the former of which transmits impulses to the lines 54, 55 and the latter energizes over lead 58 relay 49 which locks up at contacts 49a and at contacts 49b opens the circuit of the stepping magnet 28. Deenergization of magnet 28 causes contacts 28b to short-circuit relay 49 and thereby reestablish the stepping circuit which due to the movement of the switch is now completed over contact 60. Relay 42 also is released when the switch moves off normal. In this manner the switch is automatically stepped under the reciprocal control of the relay 49 and magnet 28 and an impulse is transmitted over the line wires at each step by contact 28a. The first part of the switch contact bank is appropriated to drum 10 and when the wiper 25 engages the marked contact the relay 52 is operated over the marking lead and wiper to reverse the polarity of the transmitted impulse. Similar operations occur during movement of the switch over the bank contacts associated with the drum 11, impulses of reverse polarity being transmitted when the wiper engages the marked contacts corresponding to the non-stop stations. After one-half of a revolution of the wiper 25, contacts 60 are opened and contacts 45 closed to energize magnet 63 which operates the pawl 29 and releases the drum 10, the collar 33 of which restores contact 39 and re-energizes relay 42. The apparatus is then in a normal condition ready to transmit another train description. Receiving apparatus ; storing and indicating devices. Receivers at various stations are connected in parallel across the line wires 54, 55, each receiver being operated by a polarized relay 79. The normal impulses transmitted during stepping of the switch 24, operate magnet 78 which steps the driving wheel of a record strip 70 in synchronism with the switch while the reversed polarity impulses in addition to operating the driving wheel, operate a punch magnet 75. In this manner the train description is recorded, the positions of the holes in a section of the strip being indicative of the description. The strip is associated with a hole-reading device 83 which operates indicators in accordance with the record and takes up a new section of strip when a train leaves the station. The device 83 comprises a drum driven by a motor 87 and having two sets of spring-pressed contacts 88 arranged on the periphery and adapted to be brought alternately into alignment with fixed contacts 89. The record strip is passed between the drum and contacts 89, the holes in the strip permitting appropriate contacts 88 to engage corresponding contacts 89. When a train departs, track contacts 100 are operated to energize relay 97 which at contact 97a locks up over a normal contact 104 of the drum and at contacts 97b interrupts the circuits through the sign magnets 93 to cancel the description of the train. Relay 97 also operates relay 101 which opens the original circuit of relay 97 to ensure that, in the event that operation of the hole-reading device and the consequent de-energization of relay 97, relay 97 is not re-energized to initiate an incorrect indication if a train is standing stationary over contacts 100. As soon as a predetermined length of strip is stored between the punch and the reading device contacts 82a are operated to start the motor 87, operate magnet 110 to withdraw the locking latch 112, and energize relay 95. The motor then operates the drum to draw a fresh section of punched strip on the drum a wiper 114 maintaining the circuits of the motor 87, magnet 110, and relay 95. As soon as movement commences relay 97 is released and movement continues until wiper 114 moves off the associated segment, when relay 95 is released to effect operation of the indicator magnets which are selected over contacts 88; to indicate the new train description. Fig. 3 shows the equipment necessary between two sections A, C of track when the trains over track C differ from those over track A. The final receiver R of track A has a hole-reading device which controls an indicator I and is provided with additional leads 92a which may be connected with leads 22a by a switch 122. The leads 22a constitute the marking leads of the transmitter T of the section C. Alter-' natively the leads 22a may be connected to the leads 22 connected to the code drums of the transmitter. The transmitter is brought into operation by track operated contacts 120 shown dotted in Fig. 1. The Provisional Specification describes an arrangement wherein the code drums may be mounted on a common shaft and the marking potentials determined by the settings of the drum are picked up by a brush arranged in contact with the drums and driven step by step in a direction parallel to the axes of the drums. Moreover the holereading device is operated by a step-by-step ratchet mechanism and the retransmission arrangements comprise a brush co-operating with the punched strip to send appropriate impulses to line.