Abstract: Annular envelope-sealing members are permanently affixed to and carried by the rim means upon which an envelope-enshrouded tire is mounted preparatory to its treatment within a heated pressure chamber. Mounting of the tire upon the rim means automatically brings the annular members into axial alignment with the tire and into overlying relationship with its opposite sidewalls. Each annular member is independently mounted for axial movement away from the rim means and is biased toward it so as impose a sealing force of desired non-excessive magnitude upon the tire, upon inflation thereof, notwithstanding possible variations in its sidewall width dimensions. The annular members may be so constructed as to effect sealed relationships with respective ones of the marginal edge portions of the envelope upon the tire in either of two alternative ways, at the option of each particular retreader.

Abstract: Precise positioning and securement of annular envelope-sealing members in desired relationship with a rim-mounted tire, having a replacement tread strip and a flexible impervious envelope thereon, are achieved by mating screw-threaded members carried by and extending axially of the tire-mounting rim and each of the annular members. The screw-threaded means carried by the tire-mounting rim may be and preferably is fixedly connected thereto when the rim is of a two-part type used for curing purposes, and may be releasably connected to a tire-mounting rim of a unitary cylindrical type such as is employed for the vehicular mounting of a truck tire.

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.