Ball valve

Claim 1

A ball valve comprising a plurality of outer casing elements adapted to form together an outer casing in which a movable valve body is accommodated, accommodation of said movable valve body in said outer casing being achieved by coupling said plurality of outer casing elements, a valve operating shaft journaled by said outer casing elements so as to rotate said movable valve body, an annular sealing member interposed between said movable valve body and outer casing elements to effect sealing and interception therebetween, and a resilient supporting member comprising a cone spring located on the inner bottom surface of said outer casing and having a concavo-conical surface embracingly engaging a convexo-spheric outer surface of said movable valve body so that said cone spring is burdened with the load of said movable valve body placed thereon and the surface along which said sealing member is in close contact with said movable valve body is free from influence by said load of the movable valve body, said cone spring also having an axis coincident with the rotary axis of said movable valve body, an apex received in a seat in said outer casing elements for providing substantially point contact therewith, and a plurality of slots extending from its outer periphery to associated apertures in said cone spring adjacent the center thereof.