Patent ID: 6296154
Filing Date: 2001-10-02
Classification: B05B,G01F

Abstract:
A pump attachment for a container defining a neck, comprising:a body defining an elongate chamber having a first end, a second end and an interior wall extending between said first end and said second end;a coupler sized and shaped to secure said body to a neck of a container;a shaft extending through an opening in said first end of said chamber, said shaft defining an internal flow channel;a one-piece piston reciprocally mounted within said chamber, said piston defining an inner annular surface surrounding said shaft and an upper outer annular surface sized and shaped to form a sealing engagement with said interior wall of said body and a lower outer annular surface sized and shaped to form a sealing engagement with said interior wall of said body, said piston separating said chamber into an upper portion above said piston and a lower portion below said piston;an inlet valve at said second end of said body, configured to permit the flow of fluid into said chamber and restrict the flow of fluid out of said chamber; anda biasing member between said piston and said first end of said chamber, wherein said attachment further defines a first sealing surface substantially fixed with respect to said piston and a second sealing surface substantially fixed with respect to said shaft, said first sealing surface and said second sealing surface having a first position wherein said first sealing surface and said second sealing surface cooperate to prevent the flow of liquid between said piston and said shaft and a second position wherein said first sealing surface and said second sealing surface permit the flow of liquid between said piston and said shaft.