Abstract: An envelope expander for mounting an annular envelope of a flexible resilient material upon a tire supported upon a tire support with the tire axis in a horizontal position includes a vertically disposed rigid gate-like frame having a central opening of a diameter exceeding that of a tire. A plurality of expander members adapted to grip the envelope at spaced locations along the edge of a circular opening in one side of the envelope are mounted on the frame for coordinated power driven movement radially of the frame opening between radially inner and outer end limits. With the expander members at their radially inner end limits, the envelope opening is slightly stretched and manually mounted on the members. The expanding members are then driven to their radially outer end limits, expending the envelope opening to a diameter greater than that of the tire.

Abstract: A method and apparatus for installing sidewall replacement members on a used tire carcass by attaching sidewall members to the pre-buffed and cement coated sidewalls of the tire carcass, covering each sidewall member with a flexible sidewall mold, placing a flexible curing envelope around said tire carcass including the sidewall molds and sealing the envelope in the bead area of the tire carcass. The envelope covered tire carcass is then placed in a curing chamber at a preselected temperature and pressures for time period sufficient to cure said sidewall members and bond them on said tire carcass. The sidewall members can be installed in conjunction with the installation of tread rubber on the tire.

Abstract: A spreadable ring for sealing an envelope at the bead of the tire to be retreaded during the pressure and heat treatment in an autoclave. The ring is spread with the aid of cut-outs (a lap joint) or by forming the ends on both sides of the opened section into a tongue-in-groove joint. In both cases a joint is generated which runs in the circumferential direction. Depending on the bead shape the sealing surface is cylindrical or tapered whereby lateral end stops or rims facilitate the positioning. The spreading is accomplished manually by the inherent tensioning force of the ring or with the aid of tensioning cylinders.

Abstract: This invention relates to a retread curing ring apparatus for mounting on a tire retread assembly which comprises a tire carcass having a retread area, integral side walls with inner edges, a preformed tread strip positioned on the retread area, and a flexible envelope or bag surrounding the entire retread assembly. The retread curing ring apparatus is positioned adjacent to each side of the tire carcass. The curing ring apparatus comprises a circular body with a recess adjacent to its bottom edge and positioned in said recess a circular elastomeric gasket having a channel at its bottom edge for attachment to the curing ring. The gasket is prepared from a plastic or rubber material and comprises a plurality of circumferential ribs adjacent the bead of the tire carcass which enables the clamp assemblies mounted circumferentially on the curing ring to hold the curing ring and the tire assembly in an airtight engaged position during the retread process.

Abstract: A method and apparatus for retreading a tire includes a mold segment (14) having open ends (16) and (18). A tire carcass (10) has a layer of uncured rubber (12) built up on the surface thereof. The mold (14) is disposed therearound with ribs (20) resting on the surface thereof. A semi-flexible cap (24) is disposed over the ends (16) and (18) which are separated by a gap (20). An elastic strap (26) is then wrapped about the assembly to secure the mold (14) to the built up tire carcass (10). An envelope (28) is then wrapped about the assembled tire carcass (10) to provide a radially inward force thereto. The whole assembly is then cured in a curing oven.

Abstract: The invention relates to an accessory for an "orbitread" tread builder, or the like, whereby waste rubber crumbs or buffing dust can be used for the formation of a tread strip to be applied onto a tire casing to form a new tread layer. The accessory essentially includes a feeding arrangement to feed the crumbs or dust into the screw or worm conveyor of the tread builder, where it is combined with the conventionally used rubber compound which is extruded into the required tread strip form.

Abstract: An apparatus and method for cold retreading or recapping of the running surface of a vehicle tire. A rubber, rope and cloth sectioned mold is produced utilizing a new tire male mold covered with perforated polypropylene film, uncured rubber with nylon rope at its edges and highly stretchable cloth enclosed in an envelope and cured by application of pressure and heat. A male mold is used to make the final female mold directly, or to make an intermediate mold which is used to produce a tread ring that is stretched to form a larger diameter male mold from which a final mold is prepared. The final mold is then sectioned to form one discontinuous section or two or more sections. Conveniently, one section from one size tire may be fitted with a section or sections from other size tires to form a mold to recap a third size tire. Additionally, radial inserts having the radial cross sections of the mold sections may be added to accommodate various tire sizes.

Abstract: Disclosed is a hub replacement device for use in vehicle tire retreading processes. An envelope (30) is sealed against the tire carcass sidewalls (22, 24) to provide an environmental seal of the new tread (54) on the carcass crown (50) during the vulcanization process. Three arcuate rigid plates (16, 18, 20), each with a pair of ribs (56, 58), are installed between the carcass beads (12, 14), for supporting the beads (12, 14), a predetermined distance apart along a majority of the bead circumference. Integral with each support plate (16, 18, 20) are pairs of opposing toggle clamps (32, 40) with hooked ends (36). A pair of annular discs (26, 28) are located on each side of the tire for applying a compressive force on the envelope (30) against the carcass sidewalls (22, 24). The annular discs (26, 28) are each equipped with pairs of anchor loops (42, 44) to which the hooked ends (36) of the toggle clamps (32,40) are releasably engaged.

Abstract: A tube assembly for use in a process of vulcanizing a pre-cured tread onto a tire casing is disclosed. The tube assembly includes an elastomeric tubular wall having an inner periphery with a protective non-woven fabric layer covering a major portion thereof. The fabric layer includes a plurality of polyester cords extending in parallel relation in a single ply elastomeric matrix. Longitudinal edges of the fabric are covered by thin strips of elastomer bonded to the fabric layer and the tube wall. Superimposed fabric reinforcing swatches are bonded to the fabric layer around the valve stem. The tube assembly is resistant to being damaged prematurely by the rim which supports the tire casing in the tread vulcanization process.

Abstract: A device for use in vulcanizing a premolded, precured tire tread to a tire casing in a tire retreading operation, for sealing a retreading envelope against the tire carcass in the bead area of the tire. The device comprises a pair of rigid circular ring members each sized to fit against the exterior bead portion of the tire casing, with the envelope interposed between the ring and the tire casing. A series of interconnecting springs are attached to the rings at circumferentially spaced apart locations to hold them against the tire in the bead area, and spacers attached to at least some of said springs maintain a uniform distance between the bead portions of the tire casing. A compression member on an edge of each ring member provides increased sealing pressure against the envelope on the tire.

Abstract: In combination with a tire casing, including a pre-formed, pre-cured, or uncured tread disposed about its periphery, and a curing envelope covering said tread and at least the outwardly facing side walls and bead portion of the tire casing, means are disclosed for effecting a tight and uniform seal between the said curing envelope and tire casing. These comprise a pair of annular sealing members, each having a central hub and a peripheral circumferential surface adapted to engage with the bead portion of the tire casing; a pair of unitary backing members, each having a central hub and portions at equal radial distances from the said hub which are engageable with the inwardly facing peripheral edge of said tire casing; and threaded fastener means extending between each said annular member and said backing member to enable the annular and backing members to be drawn toward one another to effect a clamping action between the members and intervening envelope and tire bead as the members are drawn together.

Abstract: A method and apparatus for retreading a tire includes a mold segment (14) having open ends (16) and (18). A tire carcass (10) has a layer of uncured rubber (12) built up on the surface thereof. The mold (14) is disposed therearound with ribs (20) resting on the surface thereof. A semi-flexible cap (24) is disposed over the ends (16) and (18) which are separated by a gap (20). An elastic strap (26) is then wrapped about the assembly to secure the mold (14) to the built up tire carcass (10). An envelope (28) is then wrapped about the assembled tire carcass (10) to provide a radially inward force thereto. The whole assembly is then cured in a curing oven.

Abstract: An apparatus and method for cold retreading or recapping of the running surface of a vehicle tire. A rubber, rope and cloth mold larger in diameter than the recap tires produced in it is produced utilizing a new tire male mold covered with perforated polypropylene film, uncured rubber with nylon rope at its edges and highly stretchable cloth enclosed in an envelope and cured by application of pressure and heat. A larger male mold is used to make the final female mold directly, or a like-size male mold is used to make an intermediate mold which is used to produce a tread ring that is stretched to form a larger diameter male mold from which a final mold is prepared. The somewhat flexible, compressible final female mold thus produced is then utilized in recapping tires by positioning it around a prepared tire carcass coated with cement, a layer of uncured rubber, and a sheet of perforated polypropylene film.

Abstract: A method for retreading vehicle tires. A carcass is provided with a prevulcanized tread and an unvulcanized tie-gum layer between the carcass and tread. A microwave applicator is located above the tread for emitting microwaves to the tire for creating heat energy in the tire. A reflector for microwaves comprising an electrically conductive material is attached in connection to or in the tie-gum layer to achieve high quality rapid vulcanization without heating the carcass.

Abstract: A tie-gum layer for retreading vehicle tires. In carrying forth retreading of a vehicle tire, a prevulcanized carcass is provided with a prevulcanized tread and an unvulcanized tie-gum layer between the carcass and tread. A microwave applicator is located above the tread for emitting microwaves to the tires for creating heat energy in the tire. A reflector for microwaves comprising an electrically conductive material is provided in association with the tie-gum layer for providing high quality rapid vulcanization without heating the carcass.

Abstract: A method and apparatus for heating pressure vessels used in the tire retreading and tire repairing industry which includes a plurality of heat exchangers in the form of plate coils associated with the pressure vessel with steam being circulated through the plate coils for heating the pressure vessel to a temperature required for vulcanizing rubber. Steam is supplied from a boiler and returned to a condensate return tank through valves and traps in order to provide a closed loop system with the steam being produced by the boiler passing through steam lines into the upper end portions of the plate coils which are attached to the pressure vessel, either interiorly or exteriorly, in a manner to radiate heat into the insulated pressure vessel in order to raise the temperature interiorly of the vessel to that required for vulcanizing rubber.

Abstract: A method and apparatus for retreading vehicle tires. A carcass is provided with a prevulcanized tread and an unvulcanized tie-gum layer between the carcass and tread. A microwave applicator is located above the tread to emit microwaves against the tire for generating heat energy in the tire whereby the tie-gum layer is vulcanized. Vulcanization of the edges of the tie-gum layer is facilitated by local heating at or in connection with said edges by heat generation outside of the tire. The heating can be effected either by utilizing a material with a high dissipation factor for microwave energy or, alternatively, by use of electric resistance wires.

Abstract: An apparatus and method for cold retreading of the running surface of a vehicle tire. A rubber and cloth mold is produced utilizing a new tire male mold covered with perforated polyethylene film, uncured rubber and highly stretchable cloth enclosed in an envelope and cured by application of pressure and heat. The somewhat flexible female mold thus produced is then utilized in recapping tires by positioning it around a prepared tire carcass coated with cement, a layer of uncured rubber, and a sheet of perforated polyethylene film. The mold and tire assembly is then enclosed in an envelope, and like assemblies are placed in a chamber where curing of the rubber layer is accomplished by inflation of the tire carcass, evacuation of the envelope, pressurization of the chamber and application of heat.

Abstract: The present invention covers the method and apparatus to retread tire casings using a precured tread system where an envelope or flexible fluid tight member is used to cover a retread tire casing assembly and then placed in an autoclave where the autoclave is pressurized and a reduced differential pressure is provided between the envelope member and the precured tread. This invention includes the automatic pressurizing of the system and the monitoring of the system during operation as a total system and/or for individual curing stations.