Pneumatic shuttle valve for a ventilator system
A pneumatic shuttle valve for a ventilator is disclosed. The pneumatic shuttle valve selectively connects one of two inlet openings to an outlet opening. The shuttle valve has a plug that is forced by gas pressure entering the second inlet opening, to move to and seal against a first sealing surface, thereby forming a passageway between the second inlet opening and the outlet opening. The plug is forced by gas entering the first inlet opening, to move to and seal against a second sealing surface, thereby forming a passageway between the first inlet opening and the outlet opening.
1. A ventilator, comprising:
a manifold having a shuttle valve passageway formed into the manifold;
the shuttle valve passageway ending in a first sealing surface;
the shuttle valve passageway coupled to a first inlet opening at the first sealing surface;
a shuttle plug cap having a second sealing surface, where the shuttle plug cap is inserted into the shuttle valve passageway with the second sealing surface facing the first sealing surface, the shuttle plug cap forming a second inlet opening where the second inlet opening is coupled to the second sealing surface;
an outlet opening intersecting with the shuttle valve passageway between the first and second sealing surfaces;
a plug captured between the first and second sealing surfaces and configured to seal against the first and second sealing surfaces, the plug forming a seal against the first sealing surface when a pressure source is coupled to the second inlet opening, the plug forming a seal against the second sealing surface when a pressure source is coupled to the first inlet opening.
2. The ventilator of claim 1 where the plug has an approximately spherical shape.
3. The ventilator of claim 1 where the plug is made from a resilient material.
4. The ventilator of claim 1 where the first sealing surface is a conical surface.
5. The ventilator of claim 1 where the first sealing surface is a square shouldered surface.
6. The ventilator of claim 1 where the first sealing surface is a concave spherical shape.
7. The ventilator of claim 1 where an inlet passageway in the manifold couples to the second inlet opening in the shuttle plug cap and the shuttle plug cap seals the shuttle valve passageway.
8. The ventilator of claim 1 where the first inlet opening couples to a compressed air inlet fixture and the second inlet opening couples to an air compressor inlet fixture.
9. The ventilator of claim 1 where the shuttle plug cap is configured to screw into the shuttle valve passageway.
10. The ventilator of claim 1 where the shuttle plug cap captures an O-ring that forms a seal between the shuttle plug cap and the shuttle valve passageway.