GB576039A - Improvements relating to braking apparatus for aircraft - Google Patents

Abstract

576,039. Valves. WESTINGHOUSE BRAKE & SIGNAL CO., Ltd., KERSHAW, A. G., SIMMONS, A. W., and PETER, L. H. Jan. 3, 1944, No. 50. [Class 135] [Also in Groups XXXIII and XXXIV] In a valve device that is used for automatically limiting the pressure applied to the brakes of aircraft land wheels in accordance with the load on the wheels, a piston which is subject to the opposing pressure of the brake cylinder and a spring carries the seat of the exhaust valve of the device and this seat is adjustable to determine the limiting pressure. As shown, passages 7, 8 are connected respectively to the pilot's valve and to the wheel brake. Passage 8 is open to chamber 13 and to chamber 14 of a piston 16 normally held in the position shown by spring 17. A member 18, 21 carrying the seat of the exhaust valve 11 screws into the piston so that it is advanced relatively to the piston when it is turned by an arm 27 and a part 25 having a pin and slot engagement 24, 26 with the member 21. With no load on the aircraft wheels, the parts are as shown, the valve 11 being unseated and the brake cylinder thus connected to atmosphere through passage 19. Operation of the arm 27 by compression of the wheel-carrying strut ori landing (see Group XXXIII) advances the member 18, 21 seating the valve 11 and opening the supply valve 10 so that if the pilot's valve has been operated the brake cylinder is supplied through passages 7, 8. When the cylinder pressure acting on piston 16 is sufficient to overcome the spring 17 this piston with member 18, 21 is moved to the right thus seating the valve 10, the amount of the piston movement and thus the cylinder pressure being dependant upon the angle of movement of the arm 27 and thus on the wheel load. The valve 10 can move independently of the valve 11 to permit exhaust of the brake cylinder through the pilot's valve.