Two-piece retread envelope

Abstract

A retread autoclave envelope for a vehicle tire casing is a two-part vacuum envelope. A first part has a generally J-shaped cross-section which provides an annular cavity for receiving a first sidewall and the peripheral tread of the tire assembly. A second portion of the envelope forms a closure along a sealed joint against the first envelope portion and lies along the tire casing sidewall. The joint has a contact surface area on the inside surface of a lip of the first part of the envelope and a surface on an outer rim of the closure formed by the second part of the envelope. The closure portion has a generally Z-shaped cross-section. The envelope parts are dimensioned such that the outer diameter of the tire assembly is greater than the inner diameter of the first part of the envelope in the crown area. The first part extends from a near side of the tread across and beyond the far shoulder of the tire assembly to the annular lip in the sealing area of the joint. The second closure envelope part is composed of a semi-rigid material dimensioned such that the outermost diameter of the closure is greater than the inner diameter of the lip of the first envelope part thereby causing an interference fit at the joint.

Dependencies are inferred from the claim text.