GB273899A - Improvements relating to pressure gauges for use in connection with tyre-inflating pumps - Google Patents

Abstract

273,899. Maxfield, A. I. B. July 9, 1926. Pneumatic-tyre pressure gauges.-A fitting between the mechanically operated pump and the tyre includes means for opening the tyre valve, a non-return valve on the pump side of a pressure gauge and a release device on the pump side of the non-return valve. A pressure gauge 4 is connected through axially bored nipples 5, 6 in alignment, with the tyre on the one hand and the pump on the other. The nipple 5 engages within one end of a flexible tube the other end of which carries the tyre valve union 2 fitted with a pin 3 for depressing the tyre valve. The nipple 6 is externally threaded and fitted with a further extension 7 which is connected at the other end to the flexible tubing leading to tha pump. The extension 7 houses a spring pressed ball valve 9 having a seating 8 and forming a non-return valve on the pump side of the gauge 4. On the pump side of the valve 9 is a pillar 11 drilled axially to form a passage leading to the bore of the extension 7 to. the upper end of the pillar. This end is normally closed by a screwed cap 12 provided with a passage 14 to the atmosphere and having the upward movement limited by a screw 15 engaging a shoulder. In use, the compressed air from the pump passes to the tyre without return and when it is desired to ascertain the pressure, the cap is unscrewed the air being by-passed to the atmosphere. In a modification, the flexible tube to the tvre is omitted and the valve union 2 is formed in one with the gauge nipple.