Supplementary tire inflator

Claim 1

A supplemental tire inflator comprising a pressurized gas cylinder; means forming a tire-inflation passage (22, 23, 37) extending from said pressurized cylinder; a manually operated valve (50, 52) controlling gas flow through said tire-inflation passage; a valve seat (36) in said tire-inflation passage downstream from said manually-operated valve; and means (at 6) for regulating the pressure of the gas after passage across the valve seat; said pressure regulating means comprising an atmospheric vent chamber (35) isolated from said tire-inflation passage; a stepped piston (60) that includes a large diameter piston section slidably mounted in said vent chamber, and a small diameter piston section (61), extending through and beyond said vent chamber; a pressure control passage (38) communicating with said tire-inflation passage downstream from said valve seat (36); a pressure-reducer valve means (63, 64) in said pressure control passage; said large diameter piston section having an end face exposed to said pressure control passage; said small diameter piston section having an end face axially aligned with said valve seat for interrupting gas flow therethrough when there is a pressure build-up in the pressure control passage; and means (at 40) establishing a leakage path around the large diameter piston section for temporarily relieving the pressure on the end face of said large diameter piston section.