Variable orifice ball value

A variable orifice ball valve comprising:

• an external housing having a longitudinal fluid bore formed through the external housing;
• a ball member rotatably positioned within said external housing having a longitudinal fluid bore formed through said ball member and defining an inner wall therethrough, said ball member having a pressure port formed therein in communication between an outer surface of said ball member and said ball member fluid bore;
• an elastically expansible sleeve member secured to said inner wall of said ball member, said elastically expansible sleeve member including opposing end portions and a middle section, the middle section being relatively thinner than the opposing end portions, only the opposing end portions being secured to the inner wall of said ball member, said elastically expansible sleeve member further defining a variable sized fluid port on a surface of said elastically expansible sleeve member facing an interior of said ball member;
• means for securing said elastically expansible sleeve member to the inner wall of said ball member, said elastically expansible sleeve member defining an expansible chamber at a location between the inner wall of said ball member and the elastically expansible sleeve member as defined by said means for securing;
• and
• a valve stem extending from said ball member and through said external housing, said valve stem including a valve stem port formed therethrough and positioned in communication with said pressure port for supplying pressurization to the expansible chamber.