Annular structure having multiple reinforcement bands
A non-pneumatic wheel with reinforcement bands that provide structural support for the wheel and a method of manufacture of such a wheel are described. The reinforcement band forms part of an annular reinforcement structure that includes a core that is cast in place between annular reinforcement bands. The core can be impregnated with a matrix material. The matrix material can also be used to form one or more elements of the non-pneumatic wheel.
1. A non-pneumatic wheel, the wheel defining radial and circumferential directions, the wheel comprising:
an annular band for supporting a ground contacting tread portion, said annular band extending about the circumferential direction;
an annular reinforcement structure positioned within said annular band, said reinforcement structure comprising:
an inner reinforcement band comprising cords and extending along the circumferential direction;
an outer reinforcement band comprising cords and extending along the circumferential direction and positioned radially-outside of said inner reinforcement band;
a core positioned at least partially between said inner and outer reinforcement bands, said core being constructed from a material that is formed in place between said inner and outer reinforcement bands and has a density of 0.75 g/cm 3 or greater;
a mounting band positioned radially-inward of said annular band; and
a plurality of web spokes connected between said annular band and said mounting band, wherein said annular band and said plurality of web spokes comprise a matrix material, and wherein said annular reinforcement structure is embedded within said matrix material;
wherein said matrix material of said annular band is an integrally molded member and seamless along the circumferential direction, and
wherein said cords of said inner reinforcement band and said outer reinforcement band are in direct contact with said matrix material of said annular band.
2. A non-pneumatic wheel as in claim 1 , wherein the inner reinforcement band is comprised of a cord selected from the group consisting of monofilament or multi-filament yarns, and the cord is wound into a helix making at least three revolutions.
3. A non-pneumatic wheel as in claim 1 , wherein said core includes an impregnated matrix material that is selected from the group consisting of thermoplastic polymers, thermosetting polymers, ceramic, concrete and organometalic compounds.
4. A non-pneumatic wheel as in claim 1 , wherein said core includes an impregnated matrix material that comprises a polyurethane.