TINC, Petru (12 Barrier Green, Ocean ReefPerth, Western Australia 6027, AU)
HONIBALL, Daniel (129 Princess Road, DoubleviewPerth, Western Australia 6018, AU)
TINC, Petru (12 Barrier Green, Ocean ReefPerth, Western Australia 6027, AU)
| The Claim Defining the Invention is as Follows:
1. A tyre comprising a body of elastomeric material, the body having two opposed side faces, a plurality of voids formed in the body, said voids comprising a first set of voids opening onto one side face and a second set of voids opening onto the other side face, each void comprising a first void section and a second void section, the first void section being of larger cross-sectional area than the second void section, the first void section having an outer end opening onto the respective side face and an inner end from which the second void section extends.
2. The tyre of claim 1 wherein the body comprises an annular body having a radially outer portion for contact with the ground, the voids being in a portion of the body disposed radially inwardly of the outer portion.
3. The tyre of claim 2 wherein the body further comprises a radially inner portion for mounting on a wheel rim, the portion of the body incorporating the voids being disposed between the radially inner and outer portions.
4. The tyre of any one of the preceding claims wherein the voids extend into the body to a depth beyond a midline of the body located halfway between the opposed side faces thereof.
5. The tyre of any one of the preceding claims wherein the relative depths of the first and second void sections differ from each other.
6. The tyre of any one of the preceding claims wherein the voids on opposed side faces of the body are circumferentially offset with respect to each other in the direction of rotational motion of the tyre such that the second void section of each void opening onto one side face of the body is disposed between the second void sections of two voids opening onto the other side face of the body.
7. The tyre of any one of the preceding claims wherein the second void sections are closed at their end opposed to the first void section.
8. The tyre of claim 7 wherein the closed end of the second void sections are of a concave configuration.
9. The tyre of any one of claims 1 to 6 wherein the second void section extends through the annular body and opens onto the opposed side face.
10. The tyre of any one of the preceding claims wherein each second void section is of a rounded profile in cross-section.
11. The tyre of any one of the preceding claims wherein each second void section is of a circular cross-section and has a cylindrical side wall.
12. The tyre of any one of the preceding claims wherein each first void section is of quadrilateral cross-section with rounded corners.
13. The tyre of any one of the preceding claims wherein the cross-section of each first void section is configured as an isosceles trapezium, with the parallel sides substantially arcuate and the two other sides congruent.
14. The tyre of claim 13 wherein the two other sides are divergent in the radially outward direction of the tyre.
15. The tyre of any one claims 1 to 12 wherein the first void section is a generally trapezium configuration in which the radially outer side is substantially arcuate and the two adjacent sides are substantially arcuate to merge with the radially outer side.
16. The tyre of any one claims 1 to 12 wherein the first void section is generally oval or of a rounded configuration.
17. The tyre of any one of the preceding claims wherein the second void section extends inwardly of the body from a generally central location within the inner end of the first void section.
18. The tyre of any one of the preceding claims wherein the tyre is an annular body of unitary construction.
19. The tyre of any one of claims 1 to 17 wherein the tyre is an annular body comprising a plurality of sections adapted to be assembled together to form the annular body.
20. The tyre of claim 18 or 19 wherein the annular body is composed of a single form of elastomeric material.
21. The tyre of claim 18 or 19 wherein the annular body is composed of a plurality of forms of elastomeric material.
22. A tyre comprising a body of elastomeric material, the body having two opposed side faces, a plurality of voids formed in the body opening onto one side face, each void comprising a first void section and a second void section, the first void section being of larger cross-sectional area than the second void section, the first void section having an outer end opening onto the side face and an inner end from which the second void section extends.
23. A tyre comprising a body of elastomeric material, the body having two opposed side faces, at least one void formed in the body opening onto one side face, each void comprising a first void section and a second void section, the first void section being of larger cross-sectional area than the second void section, the first void section having an outer end opening onto the side face and an inner end from which the second void section extends.
24. A tyre substantially as herein described with reference to the accompanying drawings. |
Tyre Construction
Field of the Invention
This invention relates to a non-pneumatic tyre.
Background Art
There have been various proposals for non-pneumatic tyres for vehicles. Typically, such tyres comprise an annular body formed of elastomeric material such as rubber. It is known to incorporate voids in the annular body in order to achieve effective cushioning as the tyre travels over uneven terrain. The configuration of the voids can be important in achieving the necessary extent of cushioning and adequate heat dissipation, as well as affording satisfactory load- supporting and handling characteristics.
It is against this background that the present invention has been developed.
Summary of the Invention
According to the invention there is provided a tyre comprising a body of elastomeric material, the body having two opposed side faces, a plurality of voids formed in the body, said voids comprising a first set of voids opening onto one side face and a second set of voids opening onto the other side face, each void comprising a first void section and a second void section, the first void section being of larger cross-sectional area than the second void section, the first void section having an outer end opening onto the respective side face and an inner end from which the second void section extends.
Preferably, the body comprises an annular body having a radially outer portion for contact with the ground, the voids being in a portion of the body disposed radially inwardly of the outer portion.
Preferably, the body further comprises a radially inner portion for mounting on a wheel rim, the portion of the body incorporating the voids being disposed between the radially inner and outer portions.
The depth of the voids may vary according to the intended application of the tyre. Preferably, the voids extend into the body to a depth beyond a midline of the body located halfway between the opposed side faces thereof. Further, the relative depths of the first and second void sections may also vary.
Preferably, the voids on opposed sides of the body are circumferentially offset with respect to each other in the direction of rotational motion of the tyre such that the second void section of each void opening onto one side face of the body is disposed between the second void sections of two voids opening onto the other side face of the body.
Preferably, the second void sections are closed at their end opposed to the first void section. The closed end of the second void sections are preferably of a concave configuration. In an alternative construction, the second void section may extend through the annular body and open onto the opposed side face.
Preferably, each second void section is of a rounded profile in cross-section. Each second void section may, for example, be of a circular cross-section and thereby have a cylindrical side wall.
Where each second void section is closed and also is of circular cross-section, it preferably has an inner end wall of concave configuration.
Preferably, each first void section is of quadrilateral cross-section with rounded corners.
Preferably, the cross-section of each first void section is configured as an isosceles trapezium, with the parallel sides somewhat arcuate and the two other sides congruent. The two other sides are preferably divergent in the radially outward direction of the tyre.
The first void section may, however, be of any other appropriate cross-sectional configuration, such as a generally trapezium configuration in which the radially outer side is arcuate and the two adjacent sides are also arcuate to merge with the radially outer side. Generally oval or other rounded configurations may also be appropriate.
Preferably, the second void section extends inwardly of the body from a generally central location within the inner end of the first void section.
Preferably, the annular body is of unitary construction. In another arrangement, the annular body may comprise a plurality of sections adapted to be assembled together to form the annular body.
The annular body may be composed of a single form of elastomeric material or a plurality of forms of elastomeric material. In the latter case, the body may comprise various layers of elastomeric material having different characteristics.
In another aspect, the present invention provides a tyre comprising a body of elastomeric material, the body having two opposed side faces, a plurality of voids formed in the body opening onto one side face, each void comprising a first void section and a second void section, the first void section being of larger cross- sectional area than the second void section, the first void section having an outer end opening onto the side face and an inner end from which the second void section extends.
In another aspect, the present invention provides a tyre comprising a body of elastomeric material, the body having two opposed side faces, at least one void formed in the body opening onto one side face, each void comprising a first void section and a second void section, the first void section being of larger cross- sectional area than the second void section, the first void section having an outer end opening onto the side face and an inner end from which the second void section extends.
Brief Description of the Drawings
The invention will be better understood by reference to the following description of one specific embodiment as shown in the accompanying drawings in which:
Figure 1 is a sectional perspective view of a tyre according to the embodiment fitted onto a wheel rim;
Figure 2 is a fragmentary elevational view of the tyre;
Figure 3 is a fragmentary cross-sectional view of the tyre on the wheel rim;
Figure 4 is a curved sectional view across the tyre; and
Figure 5 is a fragmentary curved sectional view of the tyre illustrating the relationship between voids therein.
Best Mode(s) for Carrying Out the Invention
The embodiment shown in the drawings is directed to a tyre 10 adapted to be fitted onto a wheel rim 11 having a rim portion 13 and a central disc portion 15.
The tyre 10 comprises an annular body 20 having a first outer portion 21 incorporating a tread 23 for engagement with the ground, a second inner portion 25 configured for mounting on the wheel rim 11 , and an intermediate portion 27 between the outer and inner portions 21 and 25. The body 20 also has two opposed side faces 28, 29 extending between the outer and inner portions 21 , 25.
The body 20 incorporates a plurality of voids 30 in the intermediate portion 27. The voids 30 comprise a first set of voids 31 opening onto one face 28 of the body 20 and a second set of voids 32 opening onto the other face 29 of the body.
The voids 30 are so configured and disposed that a load-bearing web structure 40 is defined within the intermediate portion 27. The load bearing web structure 40 comprises a plurality of circumferentially spaced lateral webs 41 extending inwardly from each side face 28, 29 of the body 20 to merge with a central web 43 of meandering configuration as best seen in Figures 4 and 5.
Each void 30 comprises a first (outer) void section 51 and a second (inner) void section 52. The first void section 51 extends inwardly from the respective side face 28, 29 and terminates at an inner wall 53. The second void section 52 extends inwardly from the inner wall 53 and terminates at an end wall 55.
The second void section 52 is circular in cross-section and the inner wall 55 is of a concave configuration which merges with the cylindrical side wall 57 of the second void section 52.
Each first void section 51 is of a generally quadrilateral cross-section with rounded corners. Specifically, each first void section 51 has a radially inner wall 61 , a radially outer wall 63 and two opposed side walls 67, as well as the inner wall 53 referred to previously. The side walls 67 are congruent and diverge in the radially outer direction of the tyre 10. Rounded corners 69 are provided between the various walls.
Because of the circumferential off-setting between voids 31 , 32, the second void sections 52 extending from opposed sides of the tyre 10 are in an interposed relationship, thereby creating the meandering central web portion 43.
The configuration of the voids 30 provides an extent of cushioning to the tyre which offers a more compliant (softer) ride than some of the non-pneumatic tyres currently available. It also assists with heat dissipation during operation of the tyre. More particularly, the configuration of the voids 30 presents an enlarged surface area for heat dissipation. Further, the second void sections 52, by virtue of their size and configuration, possibly also induce a pumping effect by which air within each second (smaller) void section 52 is expelled as the void section 52 compresses under load and is replaced by cooler air drawn in upon its
subsequent relaxation (expansion of the second void section 52). Still further, the configuration of the voids 30 reduces the amount of elastomeric material required for the tyre 10, resulting in a tyre 10 which is of less weight and possibly also having a lower production cost.
It should be appreciated that the scope of the invention is not limited to the scope of the embodiment described. For example, the embodiment has been described in relation to a tyre 10 having body 20 formed of elastomeric material of unitary composition. The body may, however, be formed of different materials or compositions; for example, the outer portion 21 , inner portion 25 and intermediate portion 27 may be formed of elastomeric materials of different compositions. Further, the inner portion 25 need not be of elastomeric or other resilient material. The inner potion may, for example, be of rigid material such as metal. Indeed, the inner portion may form part of a wheel rim portion to which the tyre is bonded or otherwise fitted. Further, the annular body 20 need not be of one-piece construction; for example, it may comprise a plurality of discrete sections adapted to be assembled together on a wheel rim. In another possible embodiment, the voids may extend from one side only of the tyre.
Modifications and changes can be made without departing from the scope of the invention.
Throughout the specification, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.
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