Abstract: A flexible envelope having a central portion overlying a replacement tread strip upon the tire to be retreaded has marginal edge portions overlying bands of cushion gum material upon opposite sidewalls of the tire. During the initial phase of subsequently-ensuing treatment of the aforesaid tire assembly within a heated pressure chamber, the bands of cushion gum material undergo plastic flow and create fluid-tight sealed relationships between the overlying marginal edge portions of the envelope and the underlying tire sidewalls. The bands are removed from the tire sidewalls and envelope after completion of the chamber-treatment of the assembly, and preferably before cooling thereof to ambient room temperature.

Abstract: The apparatus is used for tire-retreading of the type wherein a flexible impervious covering encloses a replacement tread strip encircling the tire and is subjected to a pressure-differential so as to maintain firm engagement between the strip and the tire during bonding of the former to the latter within a heated pressure chamber. The apparatus includes at least one such cover or shroud member whose marginal edge portions overlie opposite sidewalls of the tire and are maintained in fluid-tight, sealed relationship therewith by first and second disc-like members which overlie respective ones of the envelope edge portions and the tire sidewalls and which are urged toward each other by releasable clamping means innerconnecting their radially-innermost portions and extending generally axially through the rim-mounted tire. The replacement tread strip may be formed either of precured rubber or of rubber which is cured during the retreading operation, and the tire may be either of a pneumatic type or a solid type.

Abstract: The tire comprises a preformed carcass having a plurality of precured lugs secured to its circumferential surface by a thick layer-like mass of readily cured cushion gum material. The carcass may be of new construction but would usually be obtained by buffing the circumferential surface of a used and worn lugged tire to render the same substantially smooth and even. The lugs are separately formed by simultaneously molding and precuring retread rubber under high pressure and uniformly-applied heat, so as to possess high strength, density and cut and abrasion-resistance. The carcass, cushion gum and lugs are cemented and stitched together at ambient temperature and in a manner minimizing oxidation at their confronting surfaces. When the circumferential surface of the tire carcass to which the lugs are secured possesses a significant curvature in the width direction thereof, the exterior surfaces of the lugs may be and preferably are provided with stress-relieving grooves in their outer surfaces.

Abstract: The tire comprises a preformed carcass having a plurality of precured lugs secured to its circumferential surface by a thick layer-like mass of readily cured cushion gum material. The carcass may be of new construction but would usually be obtained by buffing the circumferential surface of a used and worn lugged tire to render the same substantially smooth and even. The lugs are separately formed by simultaneously molding and precuring retread rubber under high pressure and uniformly-applied heat, so as to possess high strength, density and cut and abrasion-resistance. The carcass, cushion gum and lugs are cemented and stitched together at ambient temperature and in a manner minimizing oxidation at their confronting surfaces. When the circumferential surface of the tire carcass to which the lugs are secured possesses a significant curvature in the width direction thereof, the exterior surfaces of the lugs may be and preferably are provided with stress-relieving grooves in their outer surfaces.