Patent ID: 7762791
Filing Date: 2010-07-27
Classification: F04B

Abstract:
1. A construction improvement of a piston valve in a compressing pump, comprising: a piston valve and a anti-backflow plastic gasket; a planar discharge base built in the center of the piston valve of the compressing pump facing towards an upper hood; an orientating lump, disposed in the top center of said discharge base and having an orientating hole punched at its center, a plurality of discharge spouts punched in each of three areas of said discharge base, the areas being spaced generally 120 degrees apart; three groups of inlet slots, which are created on the peripheral of said discharge base corresponding with said three areas of the discharge spouts, each having an inverse flare piston slice punched at its center; the anti-backflow plastic gasket being configured in a 3-blade planar shape to entirely cover the top of said discharge base and having a gap cleft created between each blade so that each said blade can closely block exactly a corresponding group of discharge spouts on said discharge base respectively; an orientating aperture being punched at the center of said anti-backflow plastic gasket having an orientating ring protruding downwards from its bottom; wherein by aligning said orientating ring on said anti-backflow plastic gasket with said discharge base, sleeving said orientating aperture with said orientating lump on the center of said discharge base in said piston valve, and inserting a tack-typed orientating shaft into said orientating hole on said orientating lump, said anti-backflow plastic gasket and said piston valve are securely assembled.