Combination umbrella and inverted bi-directional valve
A combination valve including a valve body having an inverted bi-directional valve portion and an umbrella portion is disclosed. In accordance with one aspect of the invention, a combination valve includes a valve body with a substantially cylindrical portion defining a flow path, a resilient umbrella valve portion extending annularly from the valve body and an inverted bi-directional valve portion provided in the flow path. The inverted bi-directional valve portion includes an interior surface, an exterior surface and at least one normally closed slit extending therebetween, wherein the exterior surface of the inverted bi-directional valve portion includes a generally concave curved portion when the slit is closed.
1. 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.
2. The combination valve of claim 1 wherein the first direction is along the flow path from the valve body through the slit and the second direction is generally opposite the first direction wherein flow in the second direction is from under the umbrella valve portion to around the periphery thereof.
3. The combination valve of claim 1 wherein the linear contour lies in a plane which is normal to a second plane containing the curved contour.
4. The combination valve of claim 3 wherein the slit extends along the linear contour.
5. The combination valve of claim 4 wherein the slit intersects the central longitudinal axis.
6. The combination valve of claim 5 wherein the slit is radially symmetric with respect to the central longitudinal axis.
7. The combination valve of claim 6 wherein the curved contour has a substantially constant radius of curvature from the axis of curvature.
8. The combination valve of claim 7 wherein the valve body further comprises a generally annular retention flange.
9. The combination valve of claim 1 further comprising means for supporting the interior surface of the slit valve.
10. The combination valve of claim 9 wherein said means comprises a substantially cylindrical tube disposed in said valve body adjacent the interior surface of the slit valve.
11. The combination valve of claim 10 wherein said cylindrical tube is press fit in said valve body.
12. The combination valve of claim 1 wherein said valve is formed in a unitary molded construction.
13. The combination valve of claim 12 wherein said valve is constructed of an elastomeric material selected from the group consisting of nitrile rubber, hydrogenated nitrile rubber, butyl rubber, styrene-butadiene rubber, natural rubber, polyisoprene, silicone, fluorosilicone elastomers, fluorocarbon elastomers, ethylene propylene, ethylene-propylene-diene polymers (EPDM) and combinations thereof.