U.S. Patent Specifications

A pump comprising a valve casing provided with inlet and outlet ports arranged at diametrically opposite positions, a valve provided with at least one recess transversely arranged to the axial movement of said valve reciprocating within said casing, a pump piston contained in each recess in said valve, an eccentric housed within an extension provided in said valve casing, and a connecting rod driven by said eccentric pivotally connected to said valve, said rod provided with an extension beyond the pivot point and engaging with at least one piston.