Tire for wheelchairs and the like

• US 4,514,243 A
• Filed: 07/09/1982
• Issued: 04/30/1985
• Est. Priority Date: 07/09/1982
• Status: Expired due to Term

• Current Assignee: Dan T. Moore Company
• Original Assignee: Dan T. Moore Company
• Inventors: Moore, Dan T. III, Fischer, Michael F.
• Primary Examiner(s): Boland, Lois E.
• Application Number:
  US06/396,694
• Time in Patent Office: 1,026 Days
• Field of Search: 156/112, 156/91, 156/306.6, 156/113, 156/272.4, 156/122, 156/309.3, 156/244.12, 156/244.13, 156/244.18, 156/304.1, 156/304.2, 156/304.3 , 156/304.6, 156/158, 264/173, 264/150, 264/25, 264/248, 425/174.8 E, 425/174.8 R, 152/310, 152/311, 152/312, 152/318, 152/323-329, 152/313, 152/319-322
• US Class Current: 156/113
• CPC Class Codes: B29C 65/3604 characterised by the type of elements heated by induction which remain in the joint
• CPC Class Codes: B29C 65/368 with a polymer coating
• CPC Class Codes: B29C 65/4815 Hot melt adhesives, e.g. thermoplastic adhesives
• CPC Class Codes: B29C 66/1142 Single butt to butt joints
• CPC Class Codes: B29C 66/5241 for forming coaxial connections, i.e. the profiled elements to be joined forming a zero angle relative to each other
• CPC Class Codes: B29C 66/636 using a support which remains in the joined object
• CPC Class Codes: B29C 66/71 characterised by the composition of the plastics material of the parts to be joined welding bar compositions B29C65/125
• CPC Class Codes: B29D 30/02 Solid tyres ; Moulds therefor
• CPC Class Codes: B29K 2021/00 Use of unspecified rubbers as moulding material
• CPC Class Codes: B29K 2021/003 Thermoplastic elastomers
• CPC Class Codes: B29L 2030/00 Pneumatic or solid tyres or parts thereof conveyor belts B29L2031/7092; drive belts B29L2031/7094; fourdrinier belts B29L2031/733
• CPC Class Codes: Y10T 152/10387 Separate core

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.

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.

2. A method as set forth in claim 1, wherein said core is extruded in a tubular configuration and said insert is inserted into each end of the core for a distance at least equal to the major transverse dimension of the bore of the core.