Patent GB-246502-A (GB)
Title: Improvements in automatic braking of locomotives
IPC: B61L3/08
Filed: 1926-01-22
Abstract: 246,502. Hostert, J. Jan. 22, 1925, [Convention date]. Track apparatus for stopping trains. -A rotary valve carried by the train and provided with a pendant arm which, under danger conditions, .strikes a device on the track so as to vent the train-pipe and apply the brakes, is constructed so that it may be reset pneumatically, and a handoperated valve is provided to control the resetting. A regulating cock is also provided whereby the suddenness of the brake application may be adjusted. A pivotally-mounted track stop device operated in conjunction with the semaphore signal and having a counterweight shock-absorbing arrangement is described. A lay-out in connection with a cross-over is also given, electric switches operated in conjunction with the switch points being used to prepare circuits controlling the setting of stop devices to stop a train entering an occupied section, or in case of incorrectly set switch points. Figs. 1 and 2 show the driver-operated valve by which the resetting is effected after a brake-application. A disc 2 rotatatble within a casing 1 by means of a handle 3 has ports co-operating with ports in the casing leading to three pipe connections 4, 5, 6. Figs. 5 and 6 show the train-carried valve device operated by the track device.. This com prises two casings, in one of which a cylindrical valve 15 works, the valve having ports normally closed but adapted to vent through ports 18 in the casing when the valve is displaced. The other casing contains a radial valve member 20, the member 15, 20, and a dependent arm 17 being connected so as to move together. The arm 17 is normally held against accidental displacement in the vertical position by two spring catches shown, and under normal conditions compressed air of the brake system is admitted through inlet 4, Figs. 1 and 2, ports of valve 2, outlet 6, a connecting pipe not shown, and in which the braking adjustment cock referred to above is situated, to inlet 22 of valve 15, Fig. 6, the vents 18 of which are closed. When arm 17 is displaced by striking the track device, vent ports 18 are opened and the brakes applied. The driver then moves handle 3 and valve 2 to close outlet 6 leading to valve 15, thus releasing the brakes, and at the same time opening ports whereby compressed air passes from inlet 4 to outlet 5 and thence by a pipe, not shown, to the radial member 20, which is thereby operated to return the lever 17 and valve 15 to normal position. The track device, Fig. 8, comprises an arm 23 which, under danger conditions, occupies the raised vertical position shown, against a fixed abutment 32 and in the path of arm 17. Under safety conditions, arm 23 depends vertically downwards in operative position. The arm may be operated in conjunction with the signal and, as shown, is mounted (with limited. lost motion to avoid transmission of impact shock) on a shaft provided with a pulley which receives motion from a pulley 30 on the signal post 29. Alternatively. the arm 23 may be operated by electric motor, the circuits of which (for opposite directions of movement) include contacts operated in conjunction with switch points and by trains occupying sections of the line so that the arm is automatically raised under danger conditions.