WHEEL AND TIRE ASSEMBLY, METHOD OF MANUFACTURE AND USE THEREOF

Abstract

A wheel assembly incorporating a non-pneumatic tyre, said assembly including first inner web or rib members and one or more second outer web or rib members. The web or rib members comprise flexible or resilient material where the first inner web members are less flexible or substantially more rigid than the second outer web members.

Claims

1. A wheel assembly incorporating a non-pneumatic tire, said assembly including; first inner web or rib members and one or more second outer web or rib members, said web or rib members comprising flexible or resilient material wherein the first inner web members are less flexible or substantially more rigid than the second outer web members.

2. A wheel assembly according to claim 1 wherein the second outer web or rib members are more flexible than the inner web or rib members to provide a degree of protection of the inner web or rib members from frequent small impacts during the course of use.

3. A wheel assembly according to claim 1 wherein at least the web or rib members comprise a thermoplastic polymer.

4. (canceled)

5. (canceled)

6. A wheel assembly according to claim 1 wherein the assembly includes a band member forming an annular ring around distal ends of the first inner web or rib members.

7. (canceled)

8. A wheel assembly according to claim 6 wherein the wheel assembly includes a core means forming at least part of the wheel hub.

9. (canceled)

10. A wheel assembly according to claim 8 wherein the first inner web or rib members extend outward from the wheel hub to the band member.

11. A wheel assembly according to claim 10 wherein the first inner web or rib members are non-linear in shape.

12. A wheel assembly according to claim 11 wherein the inner web members are C-shaped or S-shaped.

13. A wheel assembly according to claim 12 wherein the second outer web or rib members extend from the band member.

14. A wheel assembly according to claim 13 wherein the wheel member includes first inner and second outer band members.

15. A wheel assembly according to claim 14 wherein the band members are arranged in a concentric arrangement with the first inner web members extending between the inner and outer bands.

16. A wheel assembly according to claim 15 wherein the web or rib members comprise a series of resilient or flexible fingers including at least one bend or curve in the region where the web member meets or attaches to a band member.

17. A wheel assembly according to claim 16 wherein the second outer web or rib members are smaller in length and/or diameter than the first inner web or rib members.

18. A wheel assembly according to claim 17 wherein the first web or rib members are substantially the same shape and extend radially from the hub or inner band member.

19. A wheel assembly according to claim 18 wherein the second web or rib members are substantially the same shape and extend radially from the band member or outer band member.

20. A wheel assembly according to claim 19 wherein the outer web members or ribs are encapsulated or encased in polymeric material.

21. A wheel assembly according to claim 20 wherein the polymeric material is tire and/or tire tread material and the encapsulation prevents the outer ribs from going beyond their elastic limit.

22. A wheel assembly according to claim 21 wherein the flexible, or more flexible outer ribs are encapsulated or encased with foamed polyurethane polymeric material.

23. (canceled)

24. A wheel assembly according to claim 22 wherein the polymeric material is applied in one or more layers of different properties.

25. (canceled)

26. A wheel assembly according to claim 18 wherein the first inner web or rib members are encased or encapsulated in polymeric material.

Description

[0044] Specific embodiments of the invention are now described with reference to the following figures wherein;

[0045] FIGS. 1a and 1b shows a wheel assembly in accordance with one embodiment of the invention;

[0046] FIGS. 2a and 2b shows the wheel and tyre assembly in accordance with an embodiment of the invention; and

[0047] FIG. 3 shows an embodiment of a wheel assembly in accordance with one embodiment of the invention.

[0048] The present invention provides an apparatus and method for producing such an apparatus being a multi-purpose, puncture-proof wheel & tyre assembly.

[0049] The wheel can be made from many suitable materials relevant to the desired application, although the preferred assemblies are made from plastics materials, typically nylon for the wheel assembly and polyurethane for the tyre.

[0050] Turning to FIG. 1a which shows a wheel assembly 2 that comprises a hub 4 for attachment to a vehicle axle (not shown) and a first set of S-shaped ribs or finger members 6 extending from the hub 4 to an outer band or ring 8. The band or ring 8 has a second set of rib or finger members 10 extending outward therefrom. The wheel assembly therefore comprises inner rib members 6 and outer rib members 10.

[0051] Both sets of rib members have some flex or are deformable but importantly the outer ribs 10 are more flexible than the inner ribs 6. The outer ribs 10 are all be one direction and wider, but not joined together.

[0052] The relatively rigid inner webs are designed to be less deformable such that they would only be engaged or substantially flex on unusually and/or intermittent high loads or impacts, such as bumping up and/or down kerbs, or contacting unexpected objects, large stones etc.

[0053] The flexible outer ribs that are encapsulated with PU foam 12, as shown in FIGS. 2a and 2b. This encapsulation or embedding gives: [0054] lateral stability to the foam [0055] potential to vary the spring rate [0056] ensures a mechanical retention of the foam to the wheel [0057] the foam protects the outer ribs from going beyond their elastic limit

[0058] Using a thermoplastic material such as nylon, for the wheel assembly 2, ensures that the inner webs only deflect when needed, for example under unusually high loads. This ensures rolling resistance is minimised, which is essential for fuel economy, usually, but not limited to electricity for this application, thus maximising vehicle range before re-fuelling/re-charging.

[0059] The outer ribs 10, being of a smaller, thinner construction compared to the inner ribs 6, are therefore more flexible. These work in conjunction with the foam and outer foam tread material to provide subtle shock and vibration absorption without unduly affecting rolling resistance and therefore vehicle range.

[0060] In summary therefore, the flexible outer ribs 10 for general minor shock/vibration absorption and the inner ribs 6 for high impacts. The outer rib mouldings 6 are over-moulded with PU foam 12 for two reasons: [0061] To stop dirt ingress [0062] To stop the webs from being damaged on a very high impact when used on demanding applications

[0063] They also form a tyre for the wheel assembly.

[0064] FIG. 3 shows an embodiment where the outer ribs 10 are paired facing in opposing directions, different to the prior example where the ribs incline or depend from the hub 4 or ring 8 in the same direction. The hub assembly 4 in this example is recessed into an inner ring 8b. The inner ribs 6 therefore extend between an inner ring 8b and an outer ring 8a.