Pressure-discharged type retaining system

A pressure-discharged type retaining system consisting essentially of:

• a. a cylindrical inner element comprising:
• (i) an inner portion having an outer peripheral surface;
• (ii) an outer layer integrally formed onto said inner portion, said outer layer made of a softer material than said inner portion, and said outer layer being integrally formed onto said outer portion by melting and depositing said softer material on said inner portion to cover said outer peripheral surface of said inner portion;
• said inner element having a convex surface having a plurality of interconnected grooves axially spaced apart from one another and said outer layer being bronze having a thickness at least as great as the depth of said grooves;
• b. a tubular outer element having a bore close fit to said cylindrical element for receiving said cylindrical element so that both elements are incapable of relative movement, said outer element being capable of resilient expansion;
• c. means for supplying high-pressure fluid between said inner element and said outer element so that said outer element expands, allowing said inner element and said outer element to move relative to one another when said high-pressure fluid supply means is in a pressure-active condition;
• d. actuating means to displace said inner element relative to said outer element, comprising a drive fluid supply operative when said high-pressure fluid supply means is in a pressure-active condition;
• and
• e. axially-spaced sealing members extending circumferentially of said outer element and said inner element between said outer element and said inner element beyond opposite ends of said plurality of grooves to confine said high-pressure fluid.