Air compressor having improved valve device

Abstract: An air compressor includes a cylinder housing, a piston moved to slide in the cylinder housing in a reciprocating action to generate pressurized air, and a sealing ring engaged into the piston and having an outer peripheral channel formed in an upper portion to form an outer peripheral rib, the outer peripheral rib of the sealing ring is extended out of the piston for slidably engaging with the inner peripheral surface of the cylinder housing and for making an air tight seal between the cylinder housing and the piston even when the piston is tilted relative to the cylinder housing. The sealing ring is retained between a base member and an upper cover member of the piston. (end of abstract)