Patent ID: 7243676

Claim:
A combination valve comprising: a substantially cylindrical valve body having a central longitudinal axis and defining a flow path through said valve, a resilient umbrella portion extending annularly from the valve body and the valve body terminating at an end thereof in a slit valve portion; the slit valve portion having a curved contour about an axis of curvature extending substantially perpendicularly to and intersecting said central longitudinal axis; said slit valve portion having a linear contour perpendicular to said central longitudinal axis such that the slit valve portion is radially asymmetrical about the central longitudinal axis; at least one normally closed slit formed in the slit valve portion; the slit valve portion including an exterior surface having a generally concave curved orientation when the slit is closed; and the valve body, umbrella portion and slit valve portions being formed of elastomeric material such that the slit opens to permit flow through the slit valve portion in a first direction at or above a first predetermined pressure level and said umbrella valve portion flexibly responds to a second predetermined pressure level to permit flow in a second direction.