Patent GB-702621-A (GB)
Title: Improvements in or relating to tire inflation control systems
IPC: B60C23/00
Filed: 1951-10-30
Abstract: 702,621. Pneumatic tyres. BENDIX-WESTING- HOUSE AUTOMOTIVE AIR BRAKE CO. Oct. 30, 1951 [Oct. 30, 1950], No. 25369/51. Class 144(2) For controlling tyre inflation on a vehicle in operation, each wheel has a non-return inflation valve 46 fed via a conduit from a compressed air source 27, and a deflation valve 60 mounted diametrically opposite the inflation valve 46 for balance of the wheel. As shown the inflation valves 46 are fed via a pressure control valve 36 and conduits 28, 30, 32 ,34 leading to ducts 52, in stationary axles 18, 20, 22 and 24 which communicate with passages 50 in the rotary wheel hubs. The pressure-control valve 36 may be set to provide any desired pressure of air in the conduits 28, 30, 32, 34 or may be set to connect these conduits to atmosphere to relieve the pressure on seals 54, 56 at the rotary connection between ducts 52 and passages 50. The deflation values 60 are controlled by pressure air which is fed from the source 27 via a conduit 38, a two-way valve 58 and conduits 62, 64, 66, 68 which communicate with the deflation valves 60 via ducts 74 in the axles 18 and passages 72 in the rotary wheel hubs. The valve 58 is movable to connect the conduits 62, 64, 66, 68 either with the pressure air source, or with atmosphere to relieve the pressure on the rotary connection seals 56 and 76. The inflation valves 46, Fig. 2, each comprise a casing 84 having an outlet chamber 86 communicating with the tyre via a conduit 48 and housing a spring-pressed check valve 92 normally preventing communication with a duct 102 in the casing 84. The check valve 92 is arranged to be opened by a rod 98 connected with a spring-pressed piston member 96 which moves on the introduction of pressure air via passage 50 to a valve inlet 88, to admit pressure air to duct 102 and to open valve 92 by the rod 98. With this construction of valve 46, the dimensions of the valve 92 and piston member 96 may be arranged so that the valve 92 is opened at a preselected air-pressure in the passage 50. In an alternative arrangement, the valve 46 may be a simple non-return spring-ball valve which is operable only when the pressure in passage 50 exceeds that in the tyre. The deflation valves 60, Fig. 4, are each similar in operation to the inflation valve shown in Fig. 2 except that opening of the check valve 124 by the piston and rod 128, 130 connects the tyre with an exhaust opening 120. The valves 60 may be arranged to operate at a preselected pressure in the passages 72. In operation, to increase tyre pressure, the control valve 36 is set to the desired higher pressure, whereupon the valves 46 are operated to further inflate the tyres. The valve 36 is then set to atmosphere to allow closing of the valves 46. To decrease tyre pressure, valve 36 is set to the desired lower pressure and the valve 58 then momentarily opened and then closed, first to admit pressure air to the deflation valves 60 to lower the tyre pressures and then to exhaust the conduits 62, 64, 66, 68. As soon as the deflation valves close the inflation valves 46 operate to bring the tyre pressure to that set by the control valve 36. The valve 36 is finally moved to exhaust the pressure air in the conduits 28, 30, 32, 34.