Patent ID: 7104613
Filing Date: 2006-09-12
Classification: B60T

Abstract:
1. A pump apparatus comprising: a housing having a bore formed therethrough; a piston disposed within said bore for reciprocal movement along a longitudinal axis therein, said piston having an inlet flange extending outwardly substantially perpendicular to said longitudinal axis, said piston having a retaining flange; and an annular seal having a plurality of longitudinally extending passageways formed therein and disposed around said piston for reciprocal movement thereon, said inlet flange and said annular seal cooperating to form a check valve assembly, said check valve assembly dividing said bore into an inlet chamber and a pumping chamber, said retaining flange and said housing cooperating to form an outlet passageway of said check valve assembly, said annular seal being moveable to a first position relative to said inlet flange in which said plurality of longitudinally extending passageways communicate directly with said outlet passageway to said pumping chamber and said check valve assembly is in a flow-through position to fill said pump chamber with fluid from said inlet chamber during a fluid inlet stroke, said annular seal being moveable to a second position relative to said inlet flange in which said check valve assembly is closed.