GB683490A - Improvements in or relating to braking systems for aircraft - Google Patents

Abstract

683,490. Fluid-pressure brakes. DUNLOP RUBBER CO., Ltd. April 25, 1951 [April 29, 1950], No. 10597/50. Class 103 (i). A device for preventing the application of fluid-operated wheel brakes for aircraft before the landing-wheels rotate on touching down, comprises a bracket 101, Fig. 1, secured to a non-rotatable portion of a wheel and brake assembly, a fly-wheel 102 provided with tyres 15 adapted to contact the inner periphery of a landing-wheel rim, and centrifugal arcuate-shaped members 47 pivoted at their ends to the fly-wheel, Fig. 8, provided with light springs 48, and adapted to release a spring-loaded rod 45 operating inlet and exhaust slide valves 64, 76, Figs. 4, 5, controlling the fluid flow to the brakes via conduit 60. When the aircraft comes in to land the undercarriage is operated by fluid jacks (not shown). Pressure-fluid flows into the extension side of the jack and also into the cylinder formed in the nozzle 81, forcing the plunger 84 upwardly against compression spring 86 to turn a ratchet-wheel 87. An arm 54 in a chamber 44 of the valve body 58 is thus caused to rock, and move also an arm 62 in a separate chamber 56. The rocking of the arm 62 closes the inlet valve 64 and opens the exhaust valve 76 to the brakes. A leaf-spring 89, Fig. 1, ensures that the ratchet-wheel 87 will rotate in one direction only. The pivoting of the arm 54 also moves the operating rod 45 against the spring 50 to the left from the Fig. 1 position, causing the annular head member 46 to force the pegs 47 outwardly against springs 48. As the member 46 moves past the pegs they are returned inwardly to hold the rod 45 in the " cocked " position with the brake inlet valve 64 held closed. As the aircraft touches down the wheels rotate the fly-wheel 102, causing the centrifugal releases 47 pivoted thereto to move outwardly against the springs 48, thus allowing the members 46, 45 to move back under the action of spring 50 and open the inlet valve and close the exhaust valve so that brake pressure may be applied by the pilot. For static testing of the brakes the rod 45 may be moved manually by a rod 93 attached to a plunger 90 abutting the rod 45. The device described above may be used in conjunction with the automatic brake control described in Specification 676,708 which is referred to.