Patent GB-190906290-A (GB)
Title: Improvements in Automatic Train Controlling and Signalling Mechanism for Block Signal Systems.
Inventor: PRICE HAROLD WILBERFORCE
IPC: B61L3/22
Filed: 1909-03-16
Granted: 1909-10-14
Abstract: 6290. Price, H. W. March 16. Track apparatus for stopping trains and actuating signals on trains.- A signal-receiving apparatus on a train for use in systems in which the train receives a signal by completing through the engine frame a circuit passing from the last rail of one block to the first rail of the next applies the brake and sounds the whistle. The signalling- current by means of a relay 1 energizes an electro-magnet K and withdraws a latch K<4> on its armature from contact with a lever M. A spring H<6> rotates the lever downwards until stopped by a buffer pin L<4>, attached to a dash-pot piston immersed in oil and pressed upwards by a spring. A cam H<5> which rotates with the lever M opens a valve H<9> and allows compressed air from the pressure chamber H to pass to a whistle 15. A pinion H<3>, which also rotates with the lever M, raises a lever N. The lever N displaces a replacing piston O<1> and by a lever which engages lugs P', Fig. 6, moves to the left a slide valve P in the pressure chamber, bringing a port P<3> above a port O<8>. Compressed air passes through these ports to the top of a cylinder C and depresses a piston 32. This piston has a wedge-shaped lug 35, which presses against a plate 23, which slides in a segmental slot and operates the hand-brake lever. The piston 32 is held depressed, and the brake continues to be applied during the time in which a piston T' is being depressed by compressed air which passes from a pipe S above the piston 32 to a pipe S<1> and thence to the chamber T<1>. Afterwards the pipe S' communicates above the piston T' with a pipe S'; and, by way of port O<16>, communicating-port Q', port O<5>, and pipe O<3>, the compressed air passes through the cylinders C, T' to act upon the replacing- piston, and the apparatus is reset. The time taken by the piston T' in its movement is determined by the flow of oil from below a piston T<7> through a restricted passage T<8>. To reset the apparatus and remove the brake before the piston T' has completed its movement, the slide valve Q is moved to the right by hand, and the port Q<3> in the valve opens the port O<5> to the pressure chamber, admitting air to the resetting-cylinder. If the valve Q be held in the resetting position, it cannot prevent the application of the brake, for, if the valve be so held, when the resetting-piston has moved to its normal position, a port O<10> opens communication between the pressure chamber and the cylinder C by way of the port Q3, pipe O<3>, resetting-cylinder, pipe O<6>, port O<8>, and pipe S, and the brake is applied. The piston 32 is hollow, and a small piston 25, Fig. 9, is secured centrally within it. The piston 25 moves in a dash-pot 19<1> filled with oil, and has a spring-pressed valve which allows oil to pass freely through the piston on the upward stroke. The piston 32 with its small piston 25 is pressed upwards by a spring 33. The apparatus applies the brake by forcing the engineer's brake valve into service' position only, while the engineer is always at liberty to move the valve to ' service ' position or further on to emergency' position.