Patent GB-191406807-A (GB)
Title: Improvements in Apparatus for Controlling and Stopping Trains Independently of Drivers.
Inventor: BOUND ARTHUR FRANK
IPC: B61L3/04
Filed: 1914-03-18
Granted: 1915-03-18
Abstract: 6807. Bound, A. F., and Rowland, W. March 18. Track apparatus for stopping trains and actuating signals on trains; safety, fouling, and locking bars.-Relates to devices of the kind in which the brakes of a train are automatically applied, on overrunning a signal at danger, by a track contact causing the fracture or displacement of a prop controlling a valve on the train-pipe. The engine apparatus comprises a bracket A carrying between its fixed arm a and its pivoted arm D a rod or prop E which, on striking a track contact M', is fractured or displaced, thereby allowing the arm D to move and the valve F to open. Where vacuum brakes are used, the valve F is lifted by the pressure of the air, which thereupon enters a pipe f communicating with the train-pipe F'. In order to permit the temporary release of the brakes for a further forward movement of the train, a back-pressure valve G in the pipe f is adapted to be held on its seat by a hand-operated bell-crank lever g<1>, which also presses in a plunger h so as to sound the steam whistle H'. To advise the driver that the application of the brakes is due to the passing of a signal at danger and not to the guard &c., a device is provided which sounds the whistle H<1> on the valve F being opened. This device comprises a diaphragm J<1> working in a cylinder J and connected on its upper side with the pipe f. A small duct j in the diaphragm rod j' allows air to be exhausted by the ejector from the underside of the diaphragm. When the vacuum is destroyed in the pipe f, the diaphragm rod j<1> moves upwards and operates the whistle plunger h through a bell-crank lever k<1>. The rod E may be secured to a vertical rubber plate secured to the vertical arm of the bracket A. The track contact comprises an arm M' carrying a striking-trigger m and mounted on a vertical spindle M having a cam N which is engaged by a roller n on a slide O operated by the signal wire x. The cam N is shaped so as to be unaffected by the initial and final movements of the signal wire, expansion and contraction of the wire being thus allowed for. A weighted crank R restores the arm M' to the stop position. A second slide P<1> is connected by links p, P as shown to the first slide O, and is further connected by a link q to a treadle bar Q adapted to engage the wheels of the engine &c. On pulling the signal ' off ' the treadle bar Q is depressed and the slide P enters a slot p<1> and is locked there so long as a train is passing over the treadle bar. This prevents the brakes from being applied in the event of the signal being placed at danger before the whole train has passed the contact. The striking-trigger m is pivoted so as to move freely on its pivot against the direction of the traffic, but movement in the opposite direction is prevented by a stop-pin. A torsion spring m<3> holds the trigger in its normal position, and, in addition, a crank and pin are arranged so as to restore the trigger on the next action of the signal.