Claims
- 1. An endless rubber (flexible, elastomeric) track designed to encompass at least one drive wheel and at least one driven wheel of an associated vehicle is provided wherein said track is a two part track comprised of a polyurethane based outer tread component having an outer surface and an opposing inner surface and an underlying rubber carcass component having an inner surface and an opposing outer surface, wherein said tread outer surface is configured with raised, spaced apart lugs designed to be ground engaging, wherein said tread inner surface is chemically bonded to and/or physically interlocked with, said carcass inner surface and wherein said carcass outer surface is designed to engage at least one of said drive wheels and/or driven wheels of said vehicle.
- 2. The track of claim 1 wherein said polyurethane tread is chemically bonded to said underlying rubber carcass by an adhesive layer positioned between said tread inner surface and said carcass inner surface to bond said polyurethane tread and said rubber carcass together.
- 3. The track of claim 1 wherein said rubber carcass component contains a plurality of lugs in its outer surface which are designed to engage and/or to be guided by one or more of said vehicular drive and/or driven wheels.
- 4. The track of claim 1 wherein said polyurethane tread is a sulfur curable polyurethane which contains carbon-to-to carbon double bonds therein.
- 5. The track of claim 1 wherein said polyurethane tread is a blend of sulfur curable polyurethane and sulfur curable diene-based rubber.
- 6. The track of claim 5 wherein said diene-based rubber for said polyurethane tread blend is selected from at least one of polymers of isoprene and/or 1,3-butadiene and copolymers of styrene with isoprene and/or 1,3-butadiene.
- 7. The track of claim 6 wherein said rubber is selected from at least one of cis 1,4-polyisoprene (natural or synthetic, preferably natural), cis 1,4-butadiene, styrene/butadiene copolymers (prepared by aqueous emulsion or by organic solvent based polymerization of styrene and 1,3-butadiene), isoprene/butadiene copolymers, styrene/isoprene copolymers and styrene/isoprene/butadiene terpolymer.
- 8. The track of claim 5 wherein said polyurethane is a sulfur curable polyurethane which is blended with rubber compounding ingredients including sulfur.
- 9. The track of claim 1 wherein said polyurethane is prepared with a diisocyante selected from methylene bis(4-phenylisocyanate) or MDI, 4,4′-diphenylmethane diisocyanate or TODI, trimethyl hexamethylene diisocyanate or TMDI, or hexamethylene diisocyanate or H12MDI.
- 10. The track of claim 1 wherein said polyurethane contains a trifunctionality.
- 11. The track of claim 1 wherein said polymeric polyols are selected from at least one of polyester polyols, polyether polyols, polybutadiene polyols, polycaprolactam, and functional liquid diene prepolymers.
- 12. The track of claim 1 wherein said polyurethane tread component of the two part track is pre-formed by molding and curing a shaped polyurethane tread having raised, spaced-apart lugs on its outer surface following affixing it to an at least partially pre-cured rubber carcass by chemically bonding and/or physically interlocking the sulfur cured polyurethane-based tread to the cured rubber carcass and curing the resulting assembly.
- 13. The track of claim 12 wherein said chemical bonding is accomplished by interposing an adhesive layer between said tread and carcass and/or by chemically treating said tread and/or said carcass.
- 14. The track of claim 12 wherein said physical interlocking is accomplished by providing lugs and/or grooves in the inner surface of the pre-cured rubber carcass and opposing grooves and/or lugs in the complementary inner surface of the polyurethane tread.
- 15. The track of claim 1 wherein said polyurethane tread component is formed directly onto the surface of said track rubber carcass component by casting a liquid polyurethane reaction mixture onto the a pre-cured carcass rubber surface and curing the polyurethane reaction mixture.
- 16. The track of claim 1 wherein said polyurethane tread component is applied as a sheet of a sulfur curable polyurethane to the surface a pre-cured rubber carcass component and the polyurethane sheet cured thereon in a suitable mold to impart a raised lug configuration on the outer surface of said polyurethane tread component designed to be ground-engaging.
- 17. The track of claim 1 wherein said polyurethane tread is formed by spin casting a polyurethane reaction mixture directly onto the surface of the pre-cured rubber carcass component and curing the polyurethane reaction mixture to form the polyurethane tread.
- 18. The track of claim 1 as a sulfur cured polyurethane tread component and a cured rubber carcass component.
- 19. A vehicle comprised of at least one drive wheel and at least one driven wheel and which contains the track of claim 1 which encompasses a drive wheel and said driven wheel.
- 20. A vehicle comprised of at least one drive wheel and at least one driven wheel and which contains the track of claim 18 which encompasses a drive wheel and said driven wheel.
Parent Case Info
[0001] The Applicants hereby incorporate by reference prior U.S. Provisional Application Serial No. 60/311,773, filed on Aug. 10, 2001.
Provisional Applications (1)
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Number |
Date |
Country |
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60311773 |
Aug 2001 |
US |