GB726475A - Improvements in or relating to tyre pressure indicators - Google Patents

Abstract

726,475. Pneumatic tyres. BUDDE, C. June 3, 1953 [June 4, 1952], No. 15329/53. Class 144 (1) [Also in Group XIX] A tyre-pressure indicator and deflation warning. device comprises a cylinder 1, for mounting on a vehicle wheel. housing a floating piston 2 loaded by a spring 6 on one side and exposed on the other side to the tyre pressure via holes 8 in the cylinder wall so that on a fall in tyre pressure the piston 2 is moved by its spring 6 past the holes 8 to connect the residual air in the tyre with a connection 5 in the spring-housing end of the cylinder leading to an air-operated warning signal. As shown, the cylinder end opposite the spring 6 forms a pressure chamber 12 which is closed by a screw-on cover 7 carrying an axially adjustable pressure air inlet connection 17 in its end and having a connection 10 leading to the tyre tube. in its side wall. The connection 10 opens into an annular recess 9 in the inner surface of the cover 7 which surrounds the cylinder holes 8, and to ensure movement of the piston 2 beyond the holes 8, the chamber 12 has an additional connection with the tyre tube via a bore 16 in the cylinder wall opening into the annular recess 9. In operation, the tyre is inflated via the connection 17, the pressure air forcing the piston back against its spring 6 beyond the holes 8; at normal inflation pressure the piston retains the position shown. Operation of the warning signal may be stopped by manual axial adjustment of the connection 17 to cause its end 18 to engage the piston 2 and push it back against its spring to cover the holes 8, the connection 17 being held in this position by a sleeve 20 thereon screwing into a recess 21 in the cover 7. The cylinder 1 may be transparent and calibrated so that the position of piston 2 indicates the tyre pressure.