Patent ID: 6193482
Filing Date: 2001-02-27
Classification: F04B

Abstract:
An improved structure of a piston of an air-filing device comprising a pressure engaging ring, a top cylinder ring, an air-tightness disc, an air-tightness ring, a piston head body, a piston pin, a resilient ring, a positioning member, a bottom cylinder ring, and a linking rod, characterized in that:(a) the pressure engaging ring is used to secure the top cylinder ring onto an external edge of a protruded section located at the top of the piston head body;(b) the top cylinder ring is made from TEFLON material and has a bottom lip edge section at the interior diameter thereof and is extended from a lower section of the exterior diameter thereof to form an inclined surface,(c) the air tightness disc has a flat circular shape and has a center hole, and is used to pull and control the positioning member, the air-tightness disc is located at a protruded surface at the top of the piston head body so as to press and seal the air tightness ring, and close and seal at an air hole located at the protruded surface of the piston head body;(d) the air-tightness ring is made from a rubber material and is retained at a recess provided at a top protruded surface of the piston head body to assure air-tightness capability at the circumference of the bottom edge of the air-tightness ring;(e) the piston head body is provided with a top protruded section, and a recess is formed at the top surface of the protruded section, a plurality of air holes and center hole are provided within the recess; a bottom recess is provided below the piston head body;(f) a resilient member having elasticity is mounted to the positioning member which is functioned together with the air-tightness disc with relation to pulling and controlling of the air-tightness disc;(g) a positioning member is riveted to the air-tightness disc at the center hole; and(h) bottom cylinder ring is made from TEFLON material as one piece and is used to engage at the bottom recess of the piston head body to form into an auxiliary second cylinder ring.