GB880834A - Improvements relating to railway vehicle braking systems - Google Patents

Abstract

880,834. Fluid pressure brakes. ENGLISH ELECTRIC CO. Ltd. March 31, 1960 [March 31, 1959], No. 10831/59. Class 103 (1). A braking system for a railway vehicle includes in combination a fluid-operated reversible linear brake actuator 18 having an output member 24 coupled to the vehicle brakes through a compression spring 25, means 10, 14, 15 for supplying pressure fluid to one end of the actuator to move the member 24 to a brakesapplied position, self - operating restraining means 35, 37 effective when the member 24 has been moved to the brakes-applied position to hold the member 24 in that position independently of the supply of pressure fluid, and releasing means 44, 45 for automatically releasing the restraining means 35, 37 when pressure fluid is applied to the other end of the actuator 18 to release the brakes. The brakes are applied by pressure through pipes 15, 16, 17, piston 23 and rod 28, and are held in this position by the ratchets 37 and pawls 35; but when valve 14 is moved fluid pressure is supplied through pipes 19, 20 21 and acts on pistons 44 and 45 to disengage the pawl levers 35. The selector valve 14 is associated with a hand pump 10, and reservoir 12, and the cylinder 18 is rigidly mounted on the bogie frame 22. The forward motion of the piston 23 and the parts attached to it continue until the floating lever 30, pull rod 31 and brake lever 32 have brought the brake shoes 33 into contact with the bogie wheel 34. At the stage further delivery from pump 10 builds up a pressure behind the piston 23 until there is a sufficient force to overcome the preload on the load spring 25 and close the gap between the bottom of the spring cup 26 and the end of the loads spring plunger 27.