GB470581A - Fluid pressure braking and steering apparatus - Google Patents

Abstract

470,581. Fluid - pressure brakes. DUNLOP RUBBER CO., Ltd., WRIGHT, J., and TREVASKIS, H. Feb. 19, 1936, Nos. 5012 and 30592. [Class 103 (i)] [Also in Group XXXIII] In hydraulic braking and steering apparatus particularly for aircraft, by which equal or unequal pressures can be applied to two brakes or groups of brakes by the operation of a pair of pressure reduction valves in each of which the brake operating pressure reacts upon a spring the compression of which determines this pressure, each valve comprises an openended piston provided with ports adapted to register with ports in the valve casing. A pair of valve casings 24, 25 are connected by a bridge piece 39 forming part of a fixed base 40. Each valve device comprises a piston slide valve member 27 having a tubular end provided with ports 28 adapted to register with supply and exhaust ports 31, 34 connected to pipes 2, 4, 22, 23. Pipes 10, 11 connect with the brakes directly or as shown by stepdown pressure transformers 12, 13. A spring 36 bears on the piston 27 and a slidable cup 37, each cup being connected by a pair of links 41, 42 to pins 44, 45 secured to a member 47 guided between plates 53, 54 for radial movement with respect to a member 58 which can be turned about a shaft 65 on the base 40 by the rudder bar 20 through link 21 and arm 61. The plates are slotted at 55, 56 for the pins 44, 45. The member 47 is connected by a chain 50 and cable 7 to a finger lever 8 which may be mounted on the chief flying control 9. Each pressure transformer 12, 13 comprises a piston 67 subject to the pressure in the pipe 10 or 11 and connected to a larger piston 69 which transmits the pressure through pipe 18 or 19 to the brakes. When the pistons are in the normal position shown, the rod 75 of a valve 74 engages the end wall of the small piston chamber 72 to open the valve to connect chamber 79 through chamber 80 and pipe 14 or 15 to a supply reservoir 17. The arrangement permits of the use of a vegetable oil in the brakes and chambers 79, 80 and mineral oil in the other parts of the system. A passage 81 connects the chamber 72 with the atmosphere. Springs 83 retract the piston 69. With the rudder bar 20 in the normal position, operation of the lever 8 applies the brakes equally, the member 47 being moved along the line X X Fig. 2, so that the valve springs 36 are equally compressed by the links 41, 42. If then the rudder bar is deflected the member 58 is turned, the links of one valve are advanced and those of the other valve retracted so that the brake application is increased on one side of the machine and reduced on the other side.