Patent ID: 7681589

Claim:
In combination with a pump which comprises a fluid bore and a valve member which is positioned in the fluid bore, the fluid bore comprising a central axis and a pair of generally diametrically opposed, radially inwardly extending protrusions, the improvement comprising a retainer for the valve member which includes: a retainer head which comprises a pair of generally diametrically opposed peripheral grooves, each of which is defined by a corresponding pair of upper and lower peripheral lips; a retainer hub which is connected to or formed integrally with the retainer head and to which the valve member is movably coupled; wherein the retainer is rotatable in a plane generally perpendicular to the central axis to position each pair of upper and lower lips over a corresponding one of the inwardly extending protrusions to thereby secure the retainer to the pump and movably secure the valve member within the fluid bore; and an elongated retainer spring which is positioned in an open aperture that extends diametrically through the retainer head between the grooves, the retainer spring including a first end which is secured to the retainer head proximate one of the grooves and a second end which extends into the other of the grooves; wherein when the retainer is rotated to position the lips over their corresponding protrusions, the second end will enter a notch which is formed in one of the protrusions and thereby prevent the retainer from rotating relative to the fluid bore.