Disc valve with removable seat and unitary stem and disc, and seat and stem bushing unit therefor

Claim 1

IN A DISC VALVE OF THE TYPE HAVING A TUBULAR BODY WITH ANNULAR UNDERCUT SURFACES ABOUT ITS INNER PERIPHERY AT ITS ENDS, FLANGE MEMBERS HAVING ENGAGEMENT WITH THE ENDS OF THE BODY AND PROVIDING FITTINGS FOR SECURING THE VALVE WITHIN A CONDUIT, MEANS OF SECURING THE FLANGE MEMBERS IN ENGAGEMENT WITH THE BODY ENDS, A DISC VALVE MEMBER ROTATABLY MOUNTED WITHIN THE BODY FOR CONTROLLING FLOW THERETHROUGH, AND AN ANNULAR RESILIENT SEAT HAVING END PORTIONS DISPOSED BETWEEN SAID UNDERCUT SURFACES AND SAID FLANGE MEMBERS AND BEING SO PROPORTIONED AS TO BE UNDER COMPRESSION BETWEEN THE UNDERCUT SURFACES AND THE FLANGE MEMBERS, RESPECTIVELY, AND BETWEEN THE BODY AND DISC WHEN THE DISC IS IN CLOSED POSITION, AND HAVING A CIRCULAR STEM-OPENING THROUGH ONE WALL ON AN AXIS TRANSVERSE TO THE AXIS OF SAID ANNULAR SEAT AND OF A DIAMETER SMALLER THAN THE INNER DIAMETER OF SAID ANNULAR SEAT, THE IMPROVEMENT WHICH COMPRISES A STEM INTEGRALLY JOINED TO SAID DISC TO FORM A UNIT AND HAVING ITS AXIS IN SUBSTANTIALLY THE CENTRAL PLANE OF THE DISC AND EXTENDING LATERALLY FROM ONE EDGE OF THE DISC ALONG AN EXTENDED DIAMETER THEREOF AND EXTENDING RADIALLY THROUGH SAID STEMOPENING IN SAID SEAT AND BODY AND ROTATABLY MOUNTED IN SAID BODY FOR SUPPORTING AND ROTATING SAID DISC, SAID DISC AND STEM UNIT HAVING A CONTINUOUS OUTER SURFACE FREE FROM CRACKS AND CREVICES WITHIN THE BODY, SAID SEAT BEING SUFFICIENTLY FLEXIBLE TO CLEAR THE PORTION OF THE DISC VALVE MEMBER OPPOSITE THE STEM WHEN THE SEAT IS OUT OF THE BODY AND PERMIT THE INTEGRAL STEM AND DISC VALVE MEMBER TO BE INSERTED INTO AND REMOVED FROM THE SEAT, AND SAID BODY BEING IN TWO PARTS SEPARABLY JOINED TOGETHER ALONG A SURFACE COINCIDENT WITH THE AXIS OF A TUBULAR PORTION OF SAID SEAT WHEREBY SAID BODY MAY BE PLACED AROUND AND REMOVED FROM SAID SEAT WHILE SAID DISC VALVE MEMBER AND STEM ARE IN PLACE THEREIN.