GB542910A - Improvements in testing the inflation of pneumatic tyres on aircraft - Google Patents

Abstract

542,910. Pneumatic tyres. DUNLOP RUBBER CO., Ltd., and FLETCHER, H. R. July 30, 1940, No. 12338. [Class 144 (i)] A device for indicating deflation of tyres on aircraft during flight, and adapted to be positioned on the wheel support or aircraft structure, comprises a spring-loaded member arranged to contact the tread or side-wall of the tyre, the displacement of this member serving to operate the signalling means. As shown in Figs. 1 and 4, the device is mounted on a wheel support and comprises a cylinder 1 with a spring-loaded piston 7 the rod 6 of which is arranged to contact the tyre when the wheel is in its retracted (flight) position. Compressed air or other fluid from a supply 22 is fed to the space 19 above the piston through a pipe 21 and rotary valve 11. The valve is moved to admit the pressure fluid to the cylinder, or to exhaust the latter through a crossport 20 in the valve and a cylinder port 17, by a lever 14. In the form shown in Fig. 4, the lever 14 is adapted for manual operation. In Fig. 3, device is mounted on a fixed part of the structure, and the lever is connected by a link 26 to the wheelsupport 3. In this modification, the valve is automatically operated by movement of the wheelsupport between landing and flight positions. As shown in this Figure, the pipe line 21 is fitted with a cock 23 and pressure gauge 27. In operation, normal pressure in the tyre (registered on the gauge 27) the spring 8 holds the piston in its rearward position against the pressure in the pipe-line. On fall of pressure in the tyre, the piston 7 moves to uncover a vent port 9 in the cylinder wall thus operating the pipe-line to exhaust, the tyre-deflation being then shown on the gauge 27. As shown in Fig. 4, the valve 11 is provided with a port 18b for controlling the supply of pressure-fluid from the pipe 21 to a brake-operating pipe-line 24. Fig. 7 shows a modification in which movement of the piston rod 6, by reaction of the spring 8 on deflation of the tyre 2, brings a contact 37 across the terminals 35 of an electric circuit to operate a visible or audible signal.