Patent ID: 7762796

Claim:
A valve assembly comprising: a pump chamber having a first recess formed therein; a pump head having a second recess formed therein cooperating with the first recess to define a valve compartment, an annular valve seat extending into the valve compartment, and an opposing side of the valve compartment opposite the annular valve seat; and an apertureless flexible valve element positioned in the valve compartment and comprising: a generally circular central portion that is movable between the annular valve seat and the opposing side of the valve compartment; a pair of end tabs that are diametrically opposed to each other with respect to the generally circular central portion and that are trapped between the pump chamber and the pump head; and a pair of diametrically opposed necked down portions by which the end tabs are attached to the central portion; the flexible valve element having a flat closed configuration in which a first side of the central portion contacts the annular valve seat and a centrally-flexed open configuration in which a second side of the central portion contacts the opposing side of the valve compartment.