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US 3,941,151 AGranted
Vent pipe check valve
OwnerJoseph R. Biddleinventor
Life of this patent
Estimating the term…
Abstract
A valve assembly clamped to the upper end of a vent pipe includes an elongated sleeve with a band clamp and sealing gasket at its inner end for ready clamping to the vent pipe. A butterfly valve plate is nonrotatably fixed to a pivot shaft in unbalanced relation, with the shaft extending through the sleeve and having a transverse operator arm. Semi-annular seat means provide a sealing seat at upper and lower surfaces of the valve plate, on respective opposite sides of the pivot axis; and a spring or weight urges the valve plate to the seated position.
Claims9
A vent pipe check valve assembly comprising
- an elongated, thin-walled, cylindrical sleeve dimensioned to be clamped over the end of a vent pipe;
- said sleeve having longitudinal slots opening to its inner end to allow diameter variation at said inner end;
- a resilient annular gasket dimensioned for a snug fit within said sleeve slotted end, to provide a seal between said sleeve and a vent pipe;
- a thin-walled valve plate mounted on a transverse pivot shaft, with a major portion disposed on one side of said shaft and a minor portion disposed on the other side thereof;
- said pivot shaft being mounted transversely in said sleeve intermediate its ends, offset from the sleeve axis;
- seat means comprising resilient strip members mounted on the inner wall of said sleeve defining a seating plane in which said valve plate substantially closes said sleeve;
- said seat means comprising a first generally semi-annular member secured to the sleeve wall, for limiting outward swinging of the valve plate major portion, and a second generally semi-annular member secured to the sleeve wall, for limiting inward swinging of the valve plate minor portion;
- and means coupled to said valve plate for urging rotation thereof into said seating plane. pg,10
5 more elements
Dependencies are inferred from the claim text.