GB845044A - Improvements in and relating to jaw type track brakes - Google Patents

Abstract

845,044. Track brakes. ETABLISSEMENTS SAXBY. March 24, 1958 [March 22, 1957], No. 103 (1). In an apparatus for controlling railway track brakes, a bar 25 is placed on the track 3 in front of the movable members 1, 2 of a track brake and a force transmitting device in the form of a liquid link is interposed between the bar 25 and the movable members 1, 2 of the track brake such that the force exerted on the bar 25 by a wheel of the vehicle about to arrive at the brake can be transmitted to the movable members controlling the brake and a selection device is provided enabling the force transmitting device to be put into action or out of action depending on whether the brake is to be in the inoperative or the operative position. Fig. 1 shows the device in the inoperative position, wherein electromagnet 32 controlling distributer valve 9 is not energized and the weight of a vehicle wheel passing over bar 25 actuates piston 12 through linkwork and fluid is passed into reservoir 28. When it is desired to operate the device, the electromagnet 32 is energized, moving a first slide valve element 27 of the distributer valve 9 to the lower position shown in Fig. 2, whereby when a vehicle wheel passes over bar 25, piston 12 is actuated and the liquid link trapped between piston 12 and 6 moves the latter piston to actuate movable members 1, 2 of the track brake to retard the vehicle. The distributer valve 9 comprises a second slidevalve element 31 which is rigid with the first one (27) and which in the first position places the cylinder 7 in communication with the reservoir 28 and in the second position merely interrupts this communication.