Tire for wheelchairs and the like
First Claim
1. A method of making a tire for a wheelchair or the like, comprising the steps of extruding an elastomeric casing of relatively low modulus of elasticity over a semirigid, thermoplastic, creep-resistant hollow core of relatively high modulus of elasticity, cutting the extruded casing and core to the circumferential length of the tire, positioning a ferromagnetic insert in opposite ends of the core, said insert being coated with a thermoplastic elastomer which is fuse-compatible with the elastomer of the core, abutting the ends of the casing and core, exposing the zone of the ferromagnetic insert to high frequency electromagnetic radiation to inductively heat the surfaces of the insert and generate sufficient heat to thermally fuse the material in the vicinity of the insert to the inside surfaces of the core to effectuate a permanent coupling of the ends of the tire whereby the core provides the major resistance to hoop stress in the tire.
1 Assignment
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Accused Products
Abstract
A tire for a wheelchair wheel or the like in the form of a composite extrusion comprising a relatively soft, elastomeric casing extruded over a semirigid core. End faces of a length of extruded stock are joined by thermal fusion developed by a ferromagnetic element inserted in the tire and exposed to high frequency electromagnetic radiation.
33 Citations
2 Claims
- 1. A method of making a tire for a wheelchair or the like, comprising the steps of extruding an elastomeric casing of relatively low modulus of elasticity over a semirigid, thermoplastic, creep-resistant hollow core of relatively high modulus of elasticity, cutting the extruded casing and core to the circumferential length of the tire, positioning a ferromagnetic insert in opposite ends of the core, said insert being coated with a thermoplastic elastomer which is fuse-compatible with the elastomer of the core, abutting the ends of the casing and core, exposing the zone of the ferromagnetic insert to high frequency electromagnetic radiation to inductively heat the surfaces of the insert and generate sufficient heat to thermally fuse the material in the vicinity of the insert to the inside surfaces of the core to effectuate a permanent coupling of the ends of the tire whereby the core provides the major resistance to hoop stress in the tire.
Specification