Abstract: An air compressor including a cylinder, a motor, a reciprocating mechanism coupled to the motor, a compression mechanism reciprocated in the cylinder by the reciprocating mechanism to compress air, the compression mechanism including a base having a coupling bolt, a compressible conical piston holder and a compressible conical piston mounted around the coupling bolt of the base, wherein the coupling bolt of the base is inserted through the center holes of the compressible conical piston holder and compressible conical piston, having a head stopped above the compressible conical piston holder and the compressible conical piston, and a retainer rod raised from the head; a valve flap is slidably mounted around the retainer rod which opens the air passage through the compression mechanism during its down stroke, and close the air passage during its upstroke; a cap is mounted on the retainer rod to limit upward movement of the valve flap relative to the retainer rod.

Abstract: This invention relates to an electrical plug for automobile cigarette lighter sockets and in particular to one including a body portion formed with four slots and external threads at one end and a tubular member at the other, a cover provided with a pin at the center and threads in the inner side, two conductor rings each provided with a hole at one end and two curved portions with different curvatures, and a connector connected with the two conductor rings by a screw, whereby the electrical plug may be conveniently adapted to various kinds of automobile cigarette lighter sockets.