GB192667A - Improvements in and relating to the control of railway trains - Google Patents

Abstract

192,667. Underwood, W. J. July 17, 1922. Addition to 180,757. Electrical systems, non-automatic.- In a railway signalling system as described in the parent Specification, a relay 39, controlling the trainstop circuits is provided in connection with each switch 1, and is so connected with the signalling circuits, and with insulated track rails at the ends cf the sections that a train entering the section de-energizes the relay, which can be reenergized only by the train as it leaves the section. The bonding of rails throughout the section is obviated. The relay armatures 45, 37 are normally raised by a current from a battery 77 flowing through a fine wire winding 82 and the armature 45, so that, when the switch 1 is moved to the right to permit a train to leave the line 5 for the station B, current from a battery 35 flows through the armature 37, switch 1, trip coil 6 and the switch 1 and armature 56 to earth at station B. The coil 6 lowers a train trip-lever so that the train can leave the line 5. The first pair of wheels bridges the rails 88, 90, thereby short-circuiting the battery 77 so that the armatures 45, 37 fall and cannot be raised, and therefore the trip-coil 6 cannot again be energized from the battery 35 until the train passes over the rails 109, 112 at station B when current flows from the battery 77 through a thick wire winding 81 of the relay 39, line 84, switch 114, rails 109, 112 to earth. The relay 39 raises its armatures, and the winding 82 then retains them, but has not sufficient power to raise them alone. The cycle of operations is similar for trains in the opposite direction. Switches 80 may be provided to break the circuit of the batteries 77 if a vehicle bridges the rails 88, 90, or 86, 89 for any length of time. For a similar reason switches 95 may be provided in connection with the rails 89, 93, or a switch operated by the wheel flanges moving from the line 7 towards the points may be provided adjacent the rail 93. When passing into the line 7, the wheel flanges press a bar 115, Fig. 3, against the rail and do not move the switch member 125, but on moving out of the line 7, the flanges pass between the bar 115 and the rail, so that the lever 123 moves across its central position and is held in the open position by a spring 127 until reset by hand.