Filter having a flat resilient disc serving as both a relief and check valve

Claim 1

IN A FLUID FILTER, A FLUID TIGHT HOUSING, A TUBULAR FILTER MEMBER OF THE OUTSIDE-IN FLOW TYPE IN SAID HOUSING AND HAVING AN AXIS AND AN END FACE, A WALL CLOSING ONE END OF THE HOUSING AND HAVING A FLUID INLET AND A FLUID OUTLET THERETHROUGH, AN AXIALLY EXTENDING SLEEVE AT LEAST PARTLY CONFINED BETWEEN SAID FILTER MEMBER AND SAID END WALL, SAID SLEEVE PROVIDING AN OUTLET PASSAGE FOR FLUID CONNECTED TO SAID FLUID OUTLET, SAID SLEEVE INCLUDING A LATERALLY EXTENDING ANNULAR FLANGE THAT IS TAPERED WITH RESPECT TO SAID END WALL AND THE AXIS OF SAID FILTER MEMBER AND PROVIDES A CONICAL SEAT DISPOSED AXIALLY IN LINE WITH THE END FACE OF SAID FILTER MEMBER, SAID END FACE HAVING A CONICAL PORTION ALIGNED WITH SAID CONICAL SEAT, A SINGLE ELASTIC VALVE MEMBER FORMED OF RUBBER-LIKE MATERIAL, SAID VALVE MEMBER BEING ANNULAR AND FLAT IN UNSTRESSED CONDITION, SAID VALVE MEMBER HAVING AN ANNULAR PORTION ENGAGING SAID CONICAL SEAT, SAID CONICAL PORTION OF SAID FILTER MEMBER END FACE ENGAGING SAID VALVE MEMBER ANNULAR PORTION, SAID ANNULAR FLANGE SUPPORTING SAID FILTER MEMBER IN AXIALLY SPACED RELATION TO SAID END WALL AND SAID VALVE MEMBER ANNULAR PORTION SEALING THE CONICAL PORTION AND CONICAL SEAT AGAINST FLUID FLOW, SAID VALVE MEMBER HAVING AN ANNULAR OUTER PERIPHERAL PORTION YIELDABLY ENGAGING SAID END WALL OUTWARDLY OF SAID FLUID INLET AND ACTING AS AN ANTIDRAIN BACK VALVE MEANS TO PREVENT BACK FLOW TO FLUID FROM INSIDE THE HOUSING INTO SAID FLUID INLET, SAID OUTER PERIPHERAL PORTION YIELDING UNDER PREDETERMINED FLUID PRESSURE IN THE FLUID INLET TO MOVE AWAY FROM SAID END WALL AND PERMIT FLUID TO ENTER SAID HOUSING, SAID SLEEVE HAVING A TUBULAR PORTION FORMING SAID OUTLET PASSAGE AND SAID FLANGE HAVING A BY-PASS OPENING LOCATED LATERALLY INWARDLY OF SAID CONICAL SEAT AND OUTWARDLY OF SAID TUBULAR PORTION, SAID VALVE MEMBER HAVING AN INNER PERIPHERAL PORTION WHICH WHEN UNSTRESSED HAS A DIAMETER SUBSTANTIALLY SMALLER THAN THE DIAMETER OF SAID TUBULAR PORTION, SAID VALVE MEMBER INNER PORTION BEING STRETCHED OVER SAID TUBULAR PORTION AND ACTING TO PREVENT BY-PASS FLOW FROM SAID FLUID INLET AND BY-PASS OPENING TO SAID OUTLET PASSAGE, SAID VALVE MEMBER INNER PORTION YIELDING UNDER PREDETERMINED FLUID PRESSURE TO PERMIT UNFILTERED FLUID TO BY-PASS THE FILTER MEMBER AND FLOW TO SAID OUTLET PASSAGE, THE ELASTIC PRESSURE BETWEEN SAID INNER PERIPHERAL VALVE PORTION AND SAID TUBULAR PORTION BEING SUBSTANTIALLY GREATER THAN THE ELASTIC PRESSURE BETWEEN SAID OUTER PERIPHERAL PORTION AND SAID END WALL SO THAT SAID OUTER PORTION YIELDS TO PERMIT FLUID FLOW AT SUBSTANTIALLY LOWER FLUID PRESSURES THAN DOES SAID INNER PERIPHERAL PORTION.