Patent ID: 7032783

Claim:
A pump dispenser for liquid products, which comprises: a pump chamber including a cylinder, and a piston slidable within said cylinder and having an outlet passage extending through said piston, an inlet opening at an end of said chamber for receiving product to be dispensed, a spring within said chamber urging said piston to an extended position, an inlet check valve at said inlet opening to permit entry of product into said chamber as said piston is extended by said spring, but prevent exit of product from said chamber through said inlet opening as said piston is depressed against said spring, and an outlet check valve carried by said piston within said outlet passage to permit discharge of product from said chamber as said piston is depressed against said spring, wherein said outlet check valve comprises a concave valve body of flexible resilient construction opening away from said chamber and having an external periphery in radial surface-to-surface resilient sealing contact with an opposing radially inwardly facing wall surface of said outlet passage surrounding said valve.