| US6303060B1 | 2001-10-16 | |||
| US5328252A | 1994-07-12 | |||
| GB2124983A | 1984-02-29 | |||
| US2586206A | 1952-02-19 | |||
| EP0315897A2 | 1989-05-17 | |||
| FR2616712A1 | 1988-12-23 |
| 1. | A wheel [10] with a rim [12] having a tyre [14] mounted on the rim [12] about its periphery, the wheel [10] comprising a splitrim arrangement including a outer rim section [22] having a centering aperture [30] dimensioned for receiving an end of a wheel axis; and a inner rim section [24] disconnectably connected to the outer rim section [22] such that the outer rim section [22] and the inner rim section [24] together form the rim; and an airless, tubeless tyre [14] having a longitudinal central axis about which the tyre [14] is rotatable and comprising a tyre skeleton [66] dimensioned for engaging the rim [12] and defining an inner contour of the tyre, the skeleton [66] being characterised therein that it is adapted to maintain a substantially constant profile irrespective of air pressure within the tyre [14]; and an outer layer [68] disposed radially outwardly of and engaged with the skeleton [66] so as to define at least a circumferential groundengaging tread [70]. |
| 2. | The wheel [10] as claimed in claim 1 characterised therein that the outer rim section [22] includes a substantially continuous sidewall [26]; and an annular face [28] transversely orientated relative to the sidewall [26] and through which the centering aperture [30] extends, and further characterised therein that the sidewall [26] terminates at an end thereof in an outer rim flange [32] dimensioned for abutting the inner rim section [24]. |
| 3. | The wheel [10] as claimed in claim 2 characterised therein that the outer rim flange [32] is a circumferential, radially inwardly disposed flange and includes engaging means [34] for engaging the outer rim section [22] with the inner rim section [24]. |
| 4. | The wheel [10] as claimed in claim 3 characterised therein that the outer rim flange [32] includes a plurality of circumferentially spaced, integral, threaded projections [34] extending substantially perpendicularly from the outer rim flange [32] and dimensioned for engaging the inner rim section [24]. |
| 5. | The wheel [10] as claimed in claim 2 characterised therein that the outer rim section [22] includes a circumferential, radially outwardly disposed tyre engaging flange [36] peripherally extending from an opposite end of the sidewall [26] and suitably dimensioned for engaging a sidewall region of a tyre [14]. |
| 6. | The wheel [10] as claimed in claim 5 characterised therein that the tyre engaging flange [36] defines at least part of a gutter [62] dimensioned for accommodating a tyre edge region in use. |
| 7. | The wheel [10] as claimed in claim 1 characterised therein that the inner rim section [24] comprises a substantially continuous sidewall [38], terminating at one thereof in an inner rim flange [40], and at an opposite end thereof in a tyreengaging flange [42]. |
| 8. | The wheel [10] as claimed in claim 7 characterised therein that the inner rim flange [40] is a circumferential, radially inwardly disposed flange of substantially equal diameter to that of the outer rim flange [32] and is dimensioned to engage the outer rim flange [32] such that the sidewalls [38, 26] of the inner rim section [24] and outer rim section [22] are longitudinally aligned. |
| 9. | The wheel [10] as claimed in claims 3 and 7 characterised therein that the inner rim flange [40] includes engaging means [44] for cooperating with the engaging means of the outer rim [12] flange. |
| 10. | The wheel [10] as claimed in claims 4 and 9 characterised therein that the inner rim flange [40] includes a plurality of circumferentially spaced apertures [44] dimensioned for accommodating the threaded projections [34] of the outer rim flange [22]. |
| 11. | The wheel [10] as claimed in claim 7 characterised therein that the tyre engaging flange [42] is a circumferential, radially outwardly disposed flange extending peripherally from the sidewall of the inner rim section [24] and suitably dimensioned for engaging a sidewall region of the tyre [14], and more particularly such that the tyreengaging flanges of the outer rim section [22] and inner rim section [24] respectively engage two opposing sidewall regions of the tyre [14]. |
| 12. | The wheel [10] as claimed in claim 1 characterised therein that the splitrim arrangement includes an intermediate rim section [46] locatable between the inner and outer rim sections [24,22] so as to space the inner and outer rim sections [24,22]. |
| 13. | The wheel [10] as claimed in claim 12 characterised therein that the intermediate rim section [46] includes a substantially continuous sidewall [48] and at least one intermediate rim flange [50] dimensioned for engaging at least one of the outer rim flange [32] and the inner rim flange [40]. |
| 14. | The wheel [10] as claimed in claim 13 characterised therein that the intermediate rim section [46] includes two opposed intermediate rim flanges [50], one of which is connectable to the outer rim flange [32], while the other one is connectable to the inner rim flange [40], and particularly in such a way that the sidewalls of the inner, intermediate and outer rim sections are longitudinally aligned. |
| 15. | The wheel [10] as claimed in claim 1 characterised therein that it also comprises at least one circumferential band [20] locatable in use between two sidewall regions of the tyre [14] such that it is trapped between the rim [12] and the tyre [14]. |
| 16. | The wheel [10] as claimed in claim 15 characterised therein that the circumferential band [20] engages the rim [12] such that it separates the outer rim section [22] and the inner rim section [24], and particularly such that it is also trapped between the outer rim section [22] and the inner rim section [24]. |
| 17. | The wheel [10] as claimed in claim 15 characterised therein that the circumferential band [20] comprises a sidewall [52] and a circumferential band flange [54] laterally extending from the sidewall [52] and dimensioned for engaging at least one of the outer rim flange [32] and the inner rim flange [40]. |
| 18. | The wheel [10] as claimed in claim 17 characterised therein that the band flange [54] is a circumferential, radially inwardly disposed flange of substantially equal diameter to that of the outer and inner rim flanges [32,40] such that it is sandwiched in use intermediate the outer rim flange [32] and the inner rim flange [40]. |
| 19. | The wheel [10] as claimed in claim 17 characterised therein that the band flange [54] includes engaging means for engaging the inner rim flange [40] and/or the outer rim flange [40]. |
| 20. | The wheel [10] as claimed in claims 4,10 and 19 characterised therein that the band flange [54] includes a plurality of circumferentially spaced apertures [56] dimensioned for accommodating the threaded projections [34] of the outer rim flange [32] such that the threaded projections [34] of the outer rim flange [32] first protrude through the apertures [56] in the band flange [54] and then through the apertures [44] in the inner rim flange [40], where they may be retained by means of nuts [64] or the like fastening means. |
| 21. | The wheel [10] as claimed in claim 17 characterised therein that the sidewall [52] of the circumferential band [20] includes in a tyreengaging lip [58] dimensioned for engaging a sidewall region of the tyre. |
| 22. | The wheel [10] as claimed in claim 21 characterised therein that the sidewall [52] of the circumferential band [20] terminates at both opposing ends thereof in a peripheral, radially outwardly disposed tyreengaging lip [58] dimensioned for engaging an inner surface of a sidewall region of a tyre, and more particularly such that the circumferential band [20] snugfits in use between two tyre edge regions. |
| 23. | The wheel [10] as claimed in claims 5,7 and 21 characterised therein that the circumferential band [20] is releasably connected to the splitrim arrangement such that the tyreengaging lip [58a] of the circumferential band [20] and the tyreengaging flange [36] of the outer rim section [22] together form a first peripheral gutter [62] for housing one tyre edge region, while the second tyre engaging lip [58b] of the circumferential band [20] and the tyreengaging flange [42] of the inner rim section [24] together form a second peripheral gutter [62] for housing the other tyre edge region. |
| 24. | The wheel [10] as claimed in claim 15 characterised therein that the circumferential band [20] is longitudinally displaceable relative to the rim [12] in use. |
| 25. | The wheel [10] as claimed in claim 24 characterised therein that the sidewall [52] of the circumferential band [20] is a partially domeshaped sidewall for permitting axial displacement of the circumferential band [20] relative to the rim [12] such that one or both of the tyreengaging lips [58] are displaceable relative to the tyreengaging flanges [42,36] of the inner and outer rim sections [24,22]. |
| 26. | The wheel [10] as claimed in claim 15 characterised therein that the circumferential band [20] includes one or more reinforcing webs [60] extending between the tyreengaging lips [58] and the sidewall [52] of the circumferential band [20] for reinforcing the sidewall. |
| 27. | The wheel [10] as claimed in claim 15 characterised therein that the circumferential band [20] comprises of two or more disconnectable band segments [20a, 20b, 20c] locatable sidebyside in abutting relationship such that the sidewalls [52] of the band segments together form a substantially continuous sidewall of the circumferential band [20]. |
| 28. | The wheel [10] as claimed in claims 1 and 15 characterised therein that the splitrim arrangement and the circumferential band [20] are manufactured of a lightweight material such as steel, aluminium and elastomeric material, and further may include phosphor or the like fluorescent material. |
| 29. | The wheel [10] as claimed in claim 1 characterised therein that the wheel [10] includes one or more wings peripherally extending from the wheel assembly [16] so as to increase wind resistance and enhance rotational speed of the wheel [10] in use. |
| 30. | The wheel [10] as claimed in claim 1 characterised therein that the tyre skeleton [66] is an at least partially resilient skeleton [66] circumferentially engaging the rim [12] so as to define a substantially hollow cavity [72] between the skeleton [66] and the rim [12]. |
| 31. | The wheel [10] as claimed in claim 30 characterised therein that the skeleton [66] defines a peripheral profile of the tyre [14], and in particular extend between two axially spaced skeleton edge regions [74] dimensioned for engaging the rim, defining two selfsupporting sidewall regions [76] extending radially from the edge regions [74], and a skeleton crown [78] between the sidewall regions [76]. |
| 32. | The wheel [10] as claimed in claim 31 characterised therein that each skeleton edge region [74] includes a skeleton lip [80] suitable for engaging the rim, the skeleton lip [80] being complimentarily designed to urge against the sidewalls of the outer and inner rim sections [22,24] and to mate with the tyreengaging flanges [36,42] of the outer rim section [22] and inner rim section [24] respectively. |
| 33. | The wheel [10] as claimed in claim 1 characterised therein that the tyre skeleton [66] is a substantially continuous skeleton. |
| 34. | The wheel [10] as claimed in claim 1 characterised therein that the tyre skeleton [66] comprises of a series of skeleton segments circumferentially arranged in sidebyside relationship so as together to define the skeleton [66]. |
| 35. | The wheel [10] as claimed in claim 1 characterised therein that the skeleton [66] is embedded in the outer layer [68] of the tyre. |
| 36. | The wheel [10] as claimed in claim 1 characterised therein that the outer layer [68] is connected to the skeleton [66]. |
| 37. | The wheel [10] as claimed in claim 36 characterised therein that the tyre [14] includes at least one connecting strip [82,86] for connecting the outer layer [68] to the skeleton [66], and preferably includes a series of circumferentially aligned connecting strips [82], either embedded in or arranged on the outer layer [68], for connecting the outer layer [68] to the skeleton [66]. |
| 38. | The wheel [10] as claimed in claim 1 characterised therein that the outer layer [68] engages the skeleton [66] such that it at least partially protrudes through the skeleton. |
| 39. | The wheel [10] as claimed in claim 1 characterised therein that the skeleton [66] is of a lightweight material, including spring steel, aluminium and elastomeric material, characterised in having good shock absorption properties. |
| 40. | The wheel [10] as claimed in claim 1 characterised therein that the outer layer [68] is a rubber layer. |
| 41. | The wheel [10] as claimed in claim 1 characterised therein that the skeleton [66] is radially displaceable relative to the splitrim arrangement. |
| 42. | An airless, tubeless tyre [14] having a longitudinal central axis about which the tyre [14] is rotatable and comprising a tyre skeleton [66] dimensioned for engaging a wheel rim and defining an inner contour of the tyre, the skeleton [66] being characterised therein that it is adapted to maintain a substantially constant profile irrespective of air pressure within the tyre; and an outer layer [68] disposed radially outwardly of and engaged with the skeleton [66] so as to define at least a circumferential groundengaging tread [70]. |
| 43. | A wheel assembly [16] for supporting a tyre, the wheel assembly [16] comprising a splitrim arrangement including an outer rim section [22] having a centering aperture [30] dimensioned for receiving an end of a wheel axis; and a inner rim section [24] disconnectably connected to the outer rim section [22] such that the outer rim section [22] and the inner rim section [24] together form a wheel rim; and at least one circumferential band [20] locatable in use between two sidewall regions of a tyre [14] such that it is trapped between the tyre [14] and the splitrim arrangement. |
| 44. | A splitrim arrangement for a wheel, the splitrim arrangement comprising an outer rim section [22] having a centering aperture [30] suitable for centering the splitrim arrangement on a wheel axis; and a inner rim section [24] disconnectably connected to the outer rim section [22] such that the outer rim section [22] and the inner rim section [24] together form a wheel rim. |
| 45. | A vehicle including a wheel [10], tyre [14], wheel assembly [16] and/or split rim arrangement according to any one of claims 1,41, 42 or 43. |
| 46. | A wheel [10] substantially as herein described and exemplified with reference to the accompanying drawings. |
| 47. | An airless, tubeless tyre [14] substantially as herein described and exemplified with reference to the accompanying drawings. |
| 48. | A wheel assembly [16] for supporting a tyre substantially as herein described and exemplified with reference to the accompanying drawings. |
| 49. | A splitrim arrangement for a wheel supporting a tyre substantially as herein described and exemplified with reference to the accompanying drawings. |
Background Art Prior art tyres can be categorised into various classes, including tubeless solid tyres, tubeless pneumatic tyres and pneumatic tyres comprising one or more inner tubes.
These tyres are commonly arranged on a wheel rim which in turn is mounted to a wheel hub and wheel axle.
A tubeless solid tyre comprises of a body of substantially solid elastomeric material.
One of the primary disadvantages associated with such a tyre is that it is quite heavy because of the thickness of the elastomeric body. In addition, it is generally very expensive and has poor elastic properties, resulting in a harder ride in comparison with pneumatic tyres.
Although pneumatic tyres have better elastic properties, they suffer from a number of other disadvantages. A pneumatic tyre is vulnerable to puncturing and valve leakages, resulting in air escaping from the tyre and consequent deflation of the same. This not only causes accelerated and uneven tyre wear, but also exponential reduces tyre traction on a road surface, which can be extremely hazardous. Another disadvantage of pneumatic tyres which include inner tubes is that the inner tubes may be over-inflated, which again causes accelerated and uneven tyre wear.
A further disadvantage associated with pneumatic tyres is a lack of adaptability to various different road conditions. In particular, pneumatic tyres are vulnerable to "blowouts"or tyre bursts when tyres that are used for tar road driving are also used for off-road and sandy conditions, or in mining and exploration environments. It will be appreciated that pneumatic tyres that are suitable for use on a tar road are generally inadequate for use in, for example, desert driving conditions where hot sand temperatures can cause such creases in air temperature, and consequently air pressure within the tyre, that the tyre bursts. In order to counter this effect, pneumatic tyres are typically deflated for travelling on hot sand or on uneven gravel roads. However, not only does deflation of tyres cause increased friction on the tyre surface, which reduces the expected life span of a tyre, but a user is also confronted with the hassle to inflate the tyres again for subsequent tar road or the like hard road conditions.
Bearing the aforementioned disadvantages in mind, it will generally be appreciated that there is still a need for a tubeless, airless tyre that will alleviate the problems associated with pneumatic tyres, but at the same time will provide good elastic properties and increased life spans, at reduced costs.
Object of the invention It is an object of the present invention to provide a puncture-resistant tyre that will overcome or at least minimise some of the disadvantages associated with prior art tyres.
It is particularly an object of the invention to provide an airless, tubeless tyre, which requires no compressed air and as such cannot be over-or under-inflated, and which is adapted for equally efficient use on various surfaces including tar roads, on-and off- road conditions, and mining and exploration environments.
It is a further object of the invention to provide a durable wheel assembly with increased strength, capable of withstanding greater impact forces and adapted to retain structural integrity throughout its life span.
It is a further object of the invention to provide a wheel assembly suitable for cooperating with an airless, tubeless tyre.
It is yet a further object of the invention to provide a wheel including a wheel assembly and an airless, tubeless tyre.
Summary of the invention According to the invention there is provided a wheel with a rim having a tyre mounted on the rim about its periphery, the wheel comprising a split-rim arrangement including a outer rim section having a centering aperture dimensioned for receiving an end of a wheel axis; and a inner rim section disconnectably connected to the outer rim section such that the outer rim section and the inner rim section together form the rim; and an airless, tubeless tyre having a longitudinal central axis about which the tyre is rotatable and comprising a tyre skeleton dimensioned for engaging the rim and defining an inner contour of the tyre, the skeleton being characterised therein that it is adapted to maintain a substantially constant profile irrespective of air pressure within the tyre; and an outer layer disposed radially outwardly of and engaged with the skeleton so as to define at least a circumferential ground-engaging tread.
For the purpose of this specification, the term"airless"will be interpreted to mean non- inflated and an"airless tyre"will mean a non-inflated tyre that is adapted to operate in the absence of compressed air or any other compressed matter, although it will reasonably be appreciated that air at ambient pressure may be present in the tyre.
Also,"vehicle"includes, albeit not limited to, motor vehicles, trucks, motorbikes and aircraft.
The outer rim section may include a substantially continuous sidewall ; and an annular face transversely orientated relative to the sidewall and through which the centering aperture extends. The sidewall of the outer rim section may terminate at one end thereof in an outer rim flange dimensioned for abutting the inner rim section. The outer rim flange may be a circumferential, radially inwardly disposed flange and may include engaging means for engaging the outer rim section with the inner rim section. More particularly, the outer rim flange may include a plurality of circumferentially spaced, integral, threaded projections extending substantially perpendicularly from the outer rim flange and dimensioned for engaging the inner rim section.
The outer rim section also may include a circumferential, radially outwardly disposed tyre-engaging flange peripherally extending from an opposite end of the sidewall and suitably dimensioned for engaging a sidewall region of a tyre. More particularly, the tyre-engaging flange may define at least part of a gutter dimensioned for accommodating a tyre edge region in use.
The inner rim section may comprise a substantially continuous sidewall, terminating at one thereof in an inner rim flange, and at an opposite end thereof in a tyre-engaging flange. The inner rim flange may be a circumferential, radially inwardly disposed flange of substantially equal diameter to that of the outer rim flange. The inner rim flange may engage the outer rim flange such that the sidewalls of the inner rim section and outer rim section are longitudinally aligned.
The inner rim flange may include engaging means for cooperating with the engaging means of the outer rim flange. More particularly, the inner rim flange may include a plurality of circumferentially spaced apertures dimensioned for accommodating the threaded projections of the outer rim flange.
The tyre-engaging flange may be a circumferential, radially outwardly disposed flange extending peripherally from the sidewall of the inner rim section and may suitably be dimensioned for engaging a sidewall region of the tyre. More particularly, the arrangement may be such that in use the tyre-engaging flanges of the outer rim section and inner rim section respectively engage two opposing sidewall regions of the tyre.
The split-rim arrangement also may include an intermediate rim section locatable between the inner and outer rim sections so as to space the inner and outer rim sections. The intermediate rim section may include a substantially continuous sidewall and at least one intermediate rim flange dimensioned for engaging at least one of the outer rim flange and the inner rim flange. More specifically, the intermediate rim section may include two opposed intermediate rim flanges, one of which may be connectable to the outer rim flange, while the other one may be connectable to the inner rim flange.
The intermediate rim section may be locatable between the inner and outer rim sections such that the sidewalls of all three rim sections are longitudinally aligned.
The wheel also may comprise at least one circumferential band locatable in use between two sidewall regions of the tyre. The circumferential band may be orientated such that it is trapped between the rim and a tyre. In one form of the invention, the circumferential band may engage the rim such that it separates the outer rim section and the inner rim section, and particularly such that it is also trapped between the outer rim section and the inner rim section.
The circumferential band may comprise a sidewall and a circumferential band flange laterally extending from the sidewall and dimensioned for engaging at least one of the outer rim flange and the inner rim flange. More particularly, the band flange may be a circumferential, radially inwardly disposed flange of substantially equal diameter to that of the outer and inner rim flanges such that it is sandwiched in use intermediate the outer rim flange and the inner rim flange.
The band flange may include engaging means for engaging the inner rim flange and/or the outer rim flange. Specifically, the band flange may include a plurality of circumferentially spaced apertures dimensioned for accommodating the threaded projections of the outer rim flange such that the threaded projections of the outer rim flange first protrude through the apertures in the band flange and then through the apertures in the inner rim flange, where they may be retained by means of nuts or the like fastening means.
The sidewall of the circumferential band may include in a tyre-engaging lip dimensioned for engaging a sidewall region of the tyre. Particularly, the sidewall of the circumferential band may terminate at both opposing ends thereof in a peripheral, radially outwardly disposed tyre-engaging lip dimensioned for engaging an inner surface of a sidewall region of a tyre. More particularly, the circumferential band may be snug- fit in use between two tyre edge regions. The circumferential band may releasably be connected to the split-rim arrangement such that the tyre-engaging lip of the circumferential band and the tyre-engaging flange of the outer rim section together form a first peripheral gutter for housing one tyre edge region, while the second tyre- engaging lip of the circumferential band and the tyre-engaging flange of the inner rim section together form a second peripheral gutter for housing the other tyre edge region.
In one form of the invention, the circumferential band may longitudinally be displaceable relative to the rim in use. In particular, the sidewall of the circumferential band may be a partially dome-shaped sidewall for permitting axial displacement of the circumferential band relative to the rim such that one or both of the tyre-engaging lips are displaceable relative to the tyre-engaging flanges of the inner and outer rim sections.
The circumferential band also may include one or more reinforcing webs extending between the tyre-engaging lips and the sidewall of the circumferential band for reinforcing the sidewalls.
In one form of the invention, the circumferential band may comprise of two or more disconnectable band segments locatable side-by-side in abutting relationship such that the sidewalls of the band segments together form a substantially continuous sidewall of the circumferential band.
Both the split-rim arrangement and the circumferential band may be manufactured of a lightweight material such as steel, aluminium and elastomeric material. The manufacturing material also may be characterised therein that it includes phosphor or the like fluorescent material.
The wheel also may include one or more wings extending from the wheel assembly so as to increase wind resistance and enhance rotational speed of the wheel in use. This feature is particularly advantageous where the wheel is used on aircraft.
The airless, tubeless tyre may be characterised therein that it has puncture-resistant properties and is equally suitable for use on tar roads, on-and off-road conditions, and mining and exploration environments. The tyre skeleton may be an at least partially resilient skeleton circumferentially engaging the rim so as to define a substantially hollow cavity between the skeleton and the rim. The skeleton may define a peripheral profile of the tyre, and in particular may extend between two axially spaced skeleton edge regions dimensioned for engaging the rim, defining two self-supporting sidewall regions extending radially from the edge regions and a skeleton crown between the sidewall regions.
Each skeleton edge region may include a skeleton lip suitable for engaging the rim.
The skeleton lip may complimentarily be designed to urge against the sidewalls of the outer and inner rims sections and to mate with the tyre-engaging flanges of the outer rim section and inner rim section respectively.
The skeleton of the tyre may be a substantially continuous skeleton. In one for of the invention, the skeleton may comprise of a series of skeleton segments circumferentially arranged in side-by-side relationship so as together to define the skeleton.
In one form of the invention, the skeleton may be embedded in the outer layer of the tyre. In an alternative form of the invention, the outer layer may be connected to the skeleton. Particularly, the tyre may include at least one connecting strip for connecting the outer layer to the skeleton. More particularly, the tyre may include a series of circumferentially aligned connecting strips, either embedded in or arranged on the outer layer, for connecting the outer layer to the skeleton.
The outer layer may engage the skeleton such that it at least partially protrudes through the skeleton.
The skeleton may be of any lightweight material, including spring steel, aluminium and elastomeric material, characterised in having good shock absorption properties.
The outer layer may be a rubber layer.
According to another aspect of the invention there is provided an airless, tubeless tyre having a longitudinal central axis about which the tyre is rotatable and comprising a tyre skeleton dimensioned for engaging a wheel rim and defining an inner contour of the tyre, the skeleton being characterised therein that it is adapted to maintain a substantially constant profile irrespective of air pressure within the tyre; and an outer layer disposed radially outwardly of and engaged with the skeleton so as to define at least a circumferential ground-engaging tread.
According to another aspect of the invention there is provided a wheel assembly for supporting a tyre, the wheel assembly comprising a split-rim arrangement including a outer rim section having a centering aperture dimensioned for receiving an end of a wheel axis; and a inner rim section disconnectably connected to the outer rim section such that the outer rim section and the inner rim section together form a wheel rim; and at least one circumferential band locatable in use between two sidewall regions of a tyre such that it is trapped between the tyre and the split-rim arrangement.
According to a further aspect of the invention there is provided a split-rim arrangement for a wheel, the split-rim arrangement comprising an outer rim section having a centering aperture suitable for centering the wheel assembly on a wheel axis; and a inner rim section disconnectably connected to the outer rim section such that the outer rim section and the inner rim section together form a wheel rim.
Specific embodiment of the invention Without limiting the scope thereof, a few embodiments of the invention will now be described by way of illustration only and with reference to the accompanying drawings wherein- Figure 1 is a perspective view from one side of a wheel according to the invention; Figure 2 is a perspective view of the wheel of Figure 1 from an opposite side; Figure 3 is an exploded perspective view of a wheel assembly according to the invention, illustrating the split-rim arrangement and a continuous circumferential band; Figure 4 is an exploded perspective view of the wheel assembly of Figure 3, illustrating a segmented circumferential band; Figure 5 is an assembled perspective view of the wheel assembly of Figures 3 and 4; Figure 6 is a cross-sectional view of the wheel assembly of Figure 5 on line VI-VI, illustrating positioning of a tyre on the wheel assembly ; Figure 7 is a cross-sectional view of a tyre according to one embodiment of the invention, where the outer layer of the tyre defines a ground-engaging tread; Figure 8 is a cross-sectional view of a tyre according to a second embodiment of the invention, where the outer layer extends between two edge regions of a tyre; Figure 9 is a cross-sectional view of a tyre according to yet another embodiment of the invention, illustrating location of the intermediate rim section between the inner and outer rim sections and wherein the tyre is particularly suitable for use on heavy load vehicles; Figure 10 is a cross-sectional view of another embodiment of the tyre, wherein the tyre is particularly suitable for use on motorbikes; Figure 11 is a cross-sectional view of a tyre according to a further embodiment of the invention, where the tyre is particularly suitable for use in sandy driving conditions; and Figure 12 is a perspective view from one side of a wheel in terms of the invention, wherein the wheel includes circumferentially spaced wings, rendering the wheel particularly advantageous for use on aircraft.
A wheel according to the invention is generally designated by reference numeral 10 and includes a rim 12 and a tyre 14 mounted on the rim 12 about its periphery. More specifically, the wheel 10 comprises a wheel assembly 16 including a split-rim arrangement and a circumferential band 20, as well as an airless and tubeless tyre 14.
Referring to Figures 3 to 6, the split-rim arrangement includes an outer rim section 22 and a inner rim section 24 disconnectably connected to the outer rim section 22 such that the outer rim section 22 and the inner rim section 24 together form a wheel rim.
The outer rim section 22 includes a substantially continuous sidewall 26 and an annular face 28, which is transversely orientated relative to the sidewall 26. A centering aperture 30, which is dimensioned for receiving an end of a wheel axis, extends through the annular face 28.
The sidewall 26 of the outer rim section 22 terminates at one end thereof in an outer rim flange 32. The outer rim flange 32 is a circumferential, radially inwardly disposed flange and includes engaging means 34 for engaging the outer rim section 22 with the inner rim section 24. More particularly, the outer rim flange 32 includes a plurality of circumferentially spaced, integral, threaded projections 34 extending substantially perpendicularly from the outer rim flange 32 and dimensioned for protruding through complimentary apertures 44 on the inner rim section 24.
The outer rim section 22 also includes a radially outwardly disposed tyre-engaging flange 36 peripherally extending from an opposite end of the sidewall 26 and suitably dimensioned for engaging a sidewall region of a tyre 14. More particularly, the tyre- engaging flange 36 at least partially defines a gutter 62 (Figure 6) for accommodating a tyre edge region in use.
The inner rim section 24 also comprises a substantially continuous sidewall 38, terminating at one thereof in an inner rim flange 40, and at an opposite end thereof in a tyre-engaging flange 42. The inner rim flange 40 is a circumferential, radially inwardly disposed flange of substantially equal diameter to that of the outer rim flange 32. The inner rim flange 40 engages the outer rim flange 32 such that the sidewalls 38,26 of the inner rim section 24 and outer rim section 22 are longitudinally aligned.
The inner rim flange 40 includes a plurality of circumferentially spaced apertures 44 dimensioned for accommodating the threaded projections 34 of the outer rim section 22.
The tyre-engaging flange 42 is a circumferential, radially outwardly disposed flange extending peripherally from the sidewall 38 of the inner rim section 24 and is suitably dimensioned for engaging a sidewall region of the tyre 14. More particularly, the arrangement is such that in use the tyre-engaging flanges 36,42 of the outer rim section 22 and inner rim section 24 respectively engage two opposing sidewall regions of the tyre 14.
The split-rim arrangement also may include an intermediate rim section 46 (Figure 9), particularly for heavy load applications. The intermediate rim section 46 includes a substantially continuous sidewall 48 and two opposed intermediate rim flanges 50, one of which is connectable to the outer rim flange 32, while the other one connectable to the inner rim flange 40. The intermediate rim section 46 is locatable between the outer and inner rim sections 22,24 so as to space the outer and inner rim sections 22,24 and so that the sidewalls 26,38, 48 of all three rim sections 22,24, 46 are longitudinally aligned. The outer rim section 22, inner rim section 24 and, where applicable, the intermediate rim section 46 together form the wheel rim.
The wheel 10 may also comprise at least one circumferential band 20 which is locatable in use between two sidewall regions of the tyre 14. The circumferential band 20 is an optional feature of the wheel assembly 16. The circumferential band 20 engages the rim such that it separates the outer rim section 22 and the inner rim section 24, and particularly such that it is trapped between the outer rim section 22 and the inner rim section 24. In use, the circumferential band 20 is also trapped between the rim and the tyre 14.
The circumferential band 20 comprises a sidewall 52 and a circumferential band flange 54 having a diameter equal to that of the outer rim flange 32 and the inner rim flange 40 and laterally extending from the sidewall 52. The band flange 54 is a radially inwardly disposed flange dimensioned for engaging the outer rim flange 32 and the inner rim flange 40 such that it is sandwiched in use intermediate the outer rim flange 32 and the inner rim flange 40.
The band flange 54 also includes a plurality of circumferentially spaced apertures 56 dimensioned for accommodating the threaded projections 34 of the outer rim flange 32 such that the threaded projections 34 first protrude through the apertures 56 in the band flange 54 and then through the apertures 44 in the inner rim flange 40. Once assembled, the threaded projections 34 may be retained in place by means of nuts 64.
The sidewall 52 of the circumferential band 20 includes in a tyre-engaging lip 58 dimensioned for engaging a tyre 14. Particularly, the sidewall 52 of the circumferential band 20 terminates at both opposing ends thereof in a peripheral radially outwardly disposed tyre-engaging lip 58 dimensioned for engaging an inner surface of a sidewall region of a tyre 14. More particularly, the band 20 is snug-fit in use between the two tyre edge regions. The circumferential band 20 is connected to the split-rim arrangement such that the tyre-engaging lip 58a of the band 20 and the tyre-engaging flange 36 of the outer rim section 22 together form a first peripheral gutter 62 (Figure 6) for housing one tyre edge region, while the second tyre-engaging lip 58b of the band 20 and the tyre-engaging flange 42 of the inner rim section 24 together form a second peripheral gutter 62 (Figure 6) for housing the other tyre edge region.
The circumferential band 20 may also include one or more reinforcing webs 60 (Figure 7) extending between the tyre-engaging lips 58 and the sidewall 52 of the band 20.
In one form of the invention, the circumferential band 20 comprises of two or more disconnectable band segments 20a, 20b, 20c (Figure 4) locatable side-by-side in abutting relationship such that in use, the sidewalls 52 of the band segments 20a, 20b, 20c together form a substantially continuous sidewall of the circumferential band 20.
Reference is now made to Figures 7 to 11. The wheel 10 also includes an airless, tubeless tyre 14 having a longitudinal central axis about which the tyre 14 is rotatable.
The tyre 14 comprises a tyre skeleton 66 dimensioned for engaging the rim. The skeleton 66 defines an inner contour of the tyre 14 and is characterised therein that it is adapted to maintain a substantially constant profile irrespective of air pressure within the tyre 14. The tyre 14 also comprises an outer layer 68 disposed radially outwardly of and engaged with the skeleton 66 so as to define at least a circumferential ground- engaging tread 70.
The tyre skeleton 66 is an at least partially resilient skeleton adapted to maintain the profile of the tyre 14 while also being resiliently deformable so as to effect a smooth ride. The skeleton 66 circumferentially engages the rim, defined by the wheel assembly 16, in such a manner that it defines a substantially hollow cavity 72 between the skeleton 66 and the rim.
The skeleton 66 extends between two axially spaced skeleton edge regions 74 dimensioned for engaging the rim and includes two self-supporting sidewall regions 76 extending radially from the edge regions 74 and a skeleton crown 78 between the sidewall regions 76.
In one embodiment of the invention, each skeleton edge region 74 includes a skeleton lip 80 suitable for engaging the rim. The skeleton lip 80 is complimentarily designed to mate with the tyre-engaging flanges 36,42 of the outer rim section 22 and inner rim section 24 respectively.
In one form of the invention the skeleton 66 of the tyre 14 is a substantially continuous skeleton. In another form of the invention, the skeleton 66 comprise of a series of skeleton segments that are circumferentially arranged in side-by-side relationship so as together to define the skeleton 66.
The skeleton 66 may be embedded in the outer layer 68 of the tyre 14. In an alternative form of the invention, the outer layer 68 is connected to the skeleton 66. The outer layer 68 can be connected to the skeleton 66 by means of a series of circumferentially aligned connecting strips 82 that are either embedded in the outer layer 68, or are arranged on the outer layer 68 for connecting the outer layer 68 to the skeleton 66.
Figure 7 illustrates one embodiment of the tyre 14 according to the invention. In this embodiment of the invention, the outer layer 68 is only connected to part of the skeleton 66, and particularly only so as to define a tread 70. The outer layer 68 is connected to the skeleton 66 by means of the connecting strips 82, which are arranged in grooves moulded in the outer layer 68 and connected to the skeleton 66 by any suitable . connecting means 84. In this embodiment of the invention the outer layer 68 is additionally connected to the skeleton 66 by means of two annular connecting rings 86, connected to the two sidewall regions 76 of the skeleton 66, extending through the outer layer 68 and engaging the same with the skeleton 68 by means of appropriate bolt and nut arrangements 88. The tyre 14 further includes a coating 90 adhered to the skeleton 66 and extending between the outer layer 68 where it defines the tread 70 and the tyre- engaging flanges 36,42 of the outer and inner rim sections 22,24 respectively. The coating 90 is an aesthetic coating, typically of fluorescent plastics material.
The embodiment illustrated in Figure 8 differs in that the outer layer 68 peripherally engages the skeleton 66, not only about the crown 78 so s to define a tread 70, but also covering the sidewall regions 76 of the skeleton 66. The sidewall regions 76 are radially profiled so as to facilitate partial radial deformation of the skeleton 66, thus increasing shock-absorption properties of the tyre 14. Also, the annular connecting rings 86 are embedded in the outer layer 68 and are secured to the skeleton 66 from inside the cavity 72. This embodiment also illustrates that the tyre 14 can engage the split-rim arrangement in the absence of a circumferential band 20. It will further be appreciated that the outer rim section 22 and the inner rim section 24 may have sidewalls 26,38 of differing lengths.
Figure 9 illustrates the split rim arrangement according to the invention where the inner rim section 22 and outer rim section 24 are separated by an intermediate rim section 46.
In particular, the intermediate rim section 46 engages the outer and inner rim section 22,24 such that the inner rim flanges 50 are connectable to the inner rim flange 32 and the outer rim flange 40 respectively.
The example also illustrates an alternative embodiment of the circumferential band 20.
Particularly, in this embodiment the wheel includes two circumferential bands 20. One circumferential band 20 engages the skeleton 66 such that the band flange 54 is sandwiched between the inner rim flange 32 and intermediate rim flange 50, whilst the other circumferential band 20 engages the skeleton such that the band flange 54 is sandwiched between the outer rim flange 40 and the intermediate rim flange 50.
The skeleton 66 may be characterised therein that it has a textured exterior surface for increasing adherence of the outer layer 68 to the skeleton 66. Also, the skeleton 66 may include one or more circumferential spaced apertures 92 such that when the outer layer 68 is adhered to the skeleton 66, the outer layer 68 partially protrudes through the apertures 92, forming protrusions 94 that are visible from inside the cavity 72, thus increasing engagement of the outer layer 68 with the skeleton 66.
Figure 10 illustrates a wheel 10 that is particularly suitable for use on motorbikes. The sidewalls 26,38 of the inner rim section 22 and the outer rim section 24 are profiled to accommodate a motorbike tyre. The tyre 14 is engages the rim such that the lip formation 74 of the skeleton 66 engages the side walls 26,38 of the inner and outer rim sections 22,24 respectively.
Figure 11 illustrates yet a further embodiment of the invention where the wheel 10 is adapted for use in sand and desert driving conditions. In this embodiment of the invention, the skeleton 66 is radially displaceable relative to the inner and outer rim sections 22, 24. More particularly, the skeleton 66 engages the rim sections 22,24 such that a circumferential space 96 is defined between the skeleton 66 and the tyre- engaging flanges 36,42. The outer layer 68 includes circumferential reinforcing steel beads 98 embedded in the outer layer 68 in a region proximate the space 96. This wheel is characterised therein that upon an increase of temperature, and a consequent increase in air pressure within the cavity 72, such as is frequently experienced when travelling on hot sandy roads, the skeleton 66 is urged towards the sidewalls 26,38, while it is radially outwardly displaced until the skeleton 66 engages the tyre-engaging flanges 36,42 so as to accommodate the increase of air pressure within the cavity 72.
Figure 12 illustrates an embodiment of the wheel 10 wherein it is particularly suitable for use on aircraft. The wheel 10 includes a series of circumferentially spaced wings 100, protruding at least partially beyond the rim, so as to increase wind resistance and accompanying wheel rotation while the aircraft is airborne. In particular, when an aircraft lowers its landing gear, the aircraft wheels tend to be substantially dormant until it engages the runway, at which time the tyres are subjected to severe motion resistance, resulting in accelerated wear of the tyres. The wings 100 are aimed at effecting rotation of the wheels while the aircraft is still in the air, such that when the aircraft lands, the wheels are already turning at approximately the same speed as the aircraft speed at that time, thus limiting tyre wear and consequent replacement costs.
Tyre rotation may further be facilitated by suitable motorised means arranged in cooperation with the wheels and adapted for also increasing wheel rotation at the time when the landing gear is lowered.
It will be appreciated that many other embodiments of the invention are possible without departing from the spirit or scope of the invention as defined in the claims.
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