Patent ID: 7341168

Claim:
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; a 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; and a hand held sprayer comprising a sprayer that is in selective fluid communication with the internal flow channel through a flexible tubing; and a valve assembly for regulating the flow of fluid from said internal flow channel to said spray end, said valve assembly comprising: a valve body enclosing an inner chamber thereof, and having an inlet port and an outlet port in fluid communication with said chamber, said inlet port in further fluid communication with said internal flow channel, said outlet port in further fluid communication with said spray end; and a valve movably mounted in said valve body.