WO2011086510A2

WO2011086510A2 - Airless tyre and wheel assembly

Info

Publication number: WO2011086510A2
Application number: PCT/IB2011/050142
Authority: WO
Inventors: Pieter Johannes Labuschagne
Original assignee: Pieter Johannes Labuschagne
Priority date: 2010-01-13
Filing date: 2011-01-13
Publication date: 2011-07-21
Also published as: WO2011086510A3

Abstract

The invention relates to a motor vehicle wheel assembly (1 ) which comprises a rim (4) securable to a hub (2) and supporting a moulded polyurethane tyre carcass (9) in which the rim (4) carries around its periphery a series of space apart guides (6) extending parallel to the axis of the wheel (1) and adapted to receive complementary slides (7) projecting into the guides (6) from the carcass (9) and anchored to the carcass (9). The invention also extends to a complimentary tyre tread material and tyre tread.

Description

AIRLESS TYRE AND WHEEL ASSEMBLY FIELD OF THE INVENTION

The invention relates to an airless tyre and wheel assembly for vehicles and particularly but not exclusively to off road heavy duty vehicles.

BACKGROUND OF THE INVENTION

Airless tyre and wheel assemblies comprising tyre carcasses fitted to wheel rims have been proposed before. Such assemblies for heavy duty wheel assemblies have to date not proved highly successful due mainly to their cost, weight and lack of facility for repair.

The nature of a tread for tyres of this kind is that there is a pattern of ground engaging material with open spaces in the pattern to give a high traction capability. This pattern of exposed surfaces is usually provided by a rubber or rubber-like material. Such material is abrasion resistant but can be subject to cuts and tearing.

The desirable characteristics of such a tyre tread is to have the inherent wear resistant properties of both rubber and hard metal which will enhance the life and efficiency of the tread over a tread made of only one of these materials. The tread should also preferably be repairable and be cost effective overall. OBJECT OF THE INVENTION

One of the objects of this invention is to overcome at least these difficulties and another is to provide a wheel assembly which can be used for a wide range of motor vehicles.

A still further object of the invention is to provide a tread which will provide the desirable characteristics referred to. SUMMARY OF THE INVENTION

According to this invention there is provided a motor vehicle wheel assembly comprising a rim securable to a hub and supporting a moulded polyurethane tyre carcass in which the rim carries around its periphery a series of spaced apart guides extending parallel to the axis of the wheel and adapted to receive complementary slides projecting into the guides from the carcass and anchored to the carcass.

Further features of this invention provide for at least some of the slides to be securable in the guides, for the rim to be securable to the hub of an off road vehicle, for the guides to be supported by gusset plates against the rim and for the slides to engage in channel sectioned guides.

The invention also provides for the slides to be integral with a ring supporting the inside of the carcass and providing the anchoring of the slides to the carcass.

According to a further feature of this invention there is also provided a tyre tread material comprising an arrangement of elongated bars of rubber-like material secured between metal side plates and having means for anchoring the tread material to a tyre base material.

There is further provided for the bars to extend beyond the metal side plates and to be splayed outwardly at one end and for the side plates to be provided by the flanges of spaced apart channel sectioned metal members. These flanges may be provided with outwardly extending locating lips at each end.

This invention also provides a tyre tread comprising an arrangement of bars as defined above, secured to a tyre base material in a predetermined, preferably herringbone, pattern and for the pattern to be such that separate bars extend in two series partway across the width of a tyre from each side with the ends of the bars remote from the sides of the tyre to overlap across the centerline when arranged in a series extending around the periphery of the tyre.

There is further provided for the bars to be located in slots in the base material of the tyre with their splayed ends engaged in slots extending from the outer side walls of the tyre to beyond the centerline of the tyre; and for the channel sectioned members providing the side walls of the bars to be secured to the base rubber by fasteners extending from the channel webs into the tread base material.

Still further features of this invention provide for the rubber-like material to be a polyurethane composition and for the channel sectioned members to be made from steel.

It is to be understood that in so far as this invention is concerned, the characteristics which will be provided by the rubber-like material are the physical properties of resilience and abrasion resistance obtainable from rubber compositions.

The invention also provides for the carcass of the tyre to have a series of transversely extending passages therein and for some of these passages to have supporting ribs extending radially inwardly from their outer ends.

Yet further features of this aspect of the invention provide for the ribs to be centrally located in each alternate passage and for the remaining passages to extend alternatively from opposite sides of the carcass but not completely through the thickness of the carcass.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features of this invention will become apparent from the following descriptions of embodiments of the invention where reference will be made to the accompanying drawings in which: Figure 1 A shows a part-sectional side elevation of an extra heavy duty tyre and wheel assembly according to a first embodiment of the invention;

Figure 1 B shows detail of a sectional side view of a guide and slide of

Figure 1 A;

Figure 2 shows a part-sectional side elevation of a second embodiment of a tyre and wheel assembly according to invention, which is useful for with motor cars and trucks;

Figure 3 shows part of a tyre tread in the carcass of a tyre according to another embodiment of the invention;

Figure 4A shows a part-sectional perspective view of the tyre tread of

Figure 3; and

Figure 4B shows detail of a portion of Figure 4A.

DETAILED DESCRIPTION OF THE INVENTION Referring to Figure 1 A the cross section is that of part of a wheel assembly suitable for use with a heavy duty earth moving vehicle.

The assembly (1 ) includes a hollow hub (2) which houses the driving motor for the wheel as is usual with assemblies of this kind. The hub (2) carries a peripheral flange (3) to which is bolted the annular disc (4) of a wheel rim. The disc has openings (5) therethrough for reduction in weight while maintaining adequate strength for the disc and for permitting dissipation of heat from the assembly.

Parallel to the axis and equally spaced apart around the periphery of the disc (4) are guides (6) for slideably supporting slides (7). These slides (7) are formed integrally with a supporting ring (8) for the inside of a moulded polyurethane carcass (9) of the tyre for the wheel assembly (1 ). The ring (8) also anchors the slides (7).

The guides (6) are of outwardly directed channel section, co-axial with the axis of the wheel assembly, and are supported from the disc (4) by gusset plates (10) tapered to extend from the disc (4) to the ends of the slides (7). This is shown in Figure 1 B.

The cooperating slides (7) are formed complementary to the channel section shape of the guides (6) with the free ends of the flanges inwardly lipped to form part of the ring (8). The web (7A) and flanges (7B) of the slides (7) slideably engage the inner surfaces of the guides (6).

The guides (6) and slides (7) of at least some of the slide and guide assemblies are bolted together by bolts or other suitable fasteners through the webs (6A) of the guides (6) into the flanges (7B) of the slides (7) as shown in Figures 1 A and 1 B.

It will be appreciated that the assembly prevents relative rotation between the disc (4) and the carcass (9) of the assembly (1 ) as well as unintentional axial displacement between these components. The disc (4) will preferably be bolted by adjacent bolts (1 1 ) engaging the flange (3) on the hub (2) as is the usual practice. However should the tyre carcass (9) or tread become damaged during use, the tyre may be stripped from the assembly and replaced with minimum difficulty and down time of the vehicle. Further the carcass (9) may be repaired and thus there need be no discarding of the tyre as is the case with the present assemblies when a tyre tread is damaged.

The carcass (9) is moulded from polyurethane to provide a strong resilient body. A suitably shaped series of passages (12) extend transversely into the carcass (9) as shown to afford the desired degree of resilience to the carcass. These passages (12) also allow ventilation of the carcass as it flexes in use.

An alternative embodiment of a wheel assembly (30) is shown in Figure 2 which is suitable for use with motor cars and trucks. In addition to the passages (31 ) extending through the carcass (32), the outer walls of alternate passages (33) are supported by radially inwardly extending ribs (34). Figure 2 also illustrates an alternative shape to the openings (35) through the wheel disc (36).

It will be understood that the shape and number of openings (35) and passages (31 and 33) may vary to meet specific characteristics required in the particular use to which the wheel assembly is to be put. The slides (37) and guides (38) may also be varied in particular design without departing from the scope of this invention.

The transverse passages (31 ) through the carcass (32) form an important part of this invention and in a preferred embodiment the passages (31 ) and the ribs (39) extend through the fully width of the carcass (32).

The passages (120) interspersed between the alternate passages (120A) extend alternatively from opposite sides of the carcass (90) and the distance to which they extend can be used to control the flexibility of the tyre. Their presence also materially affects the ventilation and weight characteristics of the complete wheel assembly. The load carrying strength of the tyre is also determined by the depth of these passages (120) across the carcass (90) along with the size of the ribs (130). Alternatively the passages from either side may be in line to meet at a central dividing wall. The wheel assembly will preferably include a tyre tread as illustrated in Figure 3. In this embodiment the tyre tread (14) is provided by bars (15) arranged across the surface (16) of the tyre. The surface (16) may be a base rubber material (17) for the tyre or a band of tread supporting material secured to the base material (17). It is also possible to attach the tread directly to the polyurethane carcass (9 or 32).

The bars (15) each consist of rubber-like material which will preferably be a polyurethane composition. The base material (17) will preferably be such that it will provide some of the resilience of the whole tyre.

A herringbone pattern of slots (18) extending inwardly from the side walls of the tyre to across the centerline (19) of the tyre is provided to locate the tread components. Each component consists of a bar (15) which is splayed outwardly at its tyre engaging end (20). This end (20) is suitably secured in an undercut part (21 ) of the co-operating slot but is capable of being removed from the tyre base material when necessary as referred to below.

The outwardly extending parts of the bars (15) have their opposite faces clamped or otherwise secured to side plates provided by the outer surfaces of flanges (22) of metal channeled sectioned members (23). The webs (24) of the members (23) are releasably anchored in the base material (17) of the tyre. Screws (25) may be used to fasten the metal channeled sectioned members (23) in position. The flanges (22) will have outwardly extending lips (26) along each end so that the bars (15) will be securely located longitudinally on the tyre, as shown in Figures 4 and the detail in Figure 5.

The result is a herringbone pattern of two oppositely inclined series of tread forming assemblies as shown. Each unit of each series consists of an exposed end of a bar of rubber-like material held between metal side plates. As shown in Figure 3 the inner ends of the assemblies overlap the centerline (19) of the tyre. It will be appreciated that alternative patterns of series of tread units can be provided as may be required under different working conditions. Initial use will cause the ends of the bars (15) to wear. After continued use both the side plates (22) and bars (15) will wear away providing prolonged use before repair is necessary.

In use the tread (14) gives adequate support for the load placed on the tyre. The projecting end of the bars (15) provide a high abrasion resistance and the side plates (22) protect the bars (15) against cutting or tearing. Initial use will cause the ends of the bars (15) to wear. After continued use both the side plates (22) and bars (15) will wear away providing extended use before repair is necessary.

Repair of a tyre according to the invention requires means for securing the channel sectioned member (23) to be released, after which the remaining parts including the splayed ends (20) of the bars (15) can be withdrawn through the open ends of the slots (18). New bars (15) can then be introduced into the slots (18) and the bars (15) supported between channel sectioned members (23) as described.

It will also be appreciated that the tread units may be varied from the specific form described above. For example the flanges (22) may be separate components bonded to the bars (15) and shaped to follow the shape of the embedded parts of the bars (15). Anchoring screws (not shown) may be provided through the base material (17) to engage the embedded ends of the side plates.

Wheel assemblies included in this invention thus give a large scope for specific performance requirements.

The wheel and tyre assembly provides a robust construction necessary to withstand arduous work and enables repairs to be made with modular components.

Claims

A motor vehicle wheel assembly comprising a rim securable to a hub and supporting a moulded polyurethane tyre carcass in which the rim carries around its periphery a series of spaced apart guides extending parallel to the axis of the wheel and adapted to receive complementary slides projecting into the guides from the carcass and anchored to the carcass.

A wheel assembly as claimed in claim 1 wherein at least some of the slides are securable in the guides.

A wheel assembly as claimed in claim 1 or claim 2 wherein the rim is securable to the hub of an off road vehicle.

A wheel assembly as claimed in any of claims 1 to 3 wherein the guides are supported by gusset plates against the rim.

A wheel assembly as claimed in any of the claims 1 to 3 wherein the slides engage in channel sectioned guides.

A wheel assembly as claimed in any of the preceding claims wherein the slides are integral with a ring supporting the inside of the carcass and providing the anchoring of the slides to the carcass.

A tyre tread material comprising an arrangement of elongated bars of rubber-like material secured between metal side plates and having means for anchoring the tread material to a tyre base material.

A tyre tread material as claimed in claim 7 wherein the bars extend beyond the metal side plates and are splayed outwardly at one end.

9. A tyre tread material as claimed in claim 7 or claim 8 wherein the side plates are provided by the flanges of spaced apart channel sectioned metal members.

10. A tyre tread material as claimed in claim 9 wherein the flanges are provided with outwardly extending locating lips at each end.

1 1. A tyre tread comprising an arrangement of bars as claimed in any one of claims 7 to 10 secured to a tyre base material in a predetermined pattern, wherein the pattern is such that separate bars extend in two series partway across the width of a tyre from each side with the ends of the bars remote from the sides of the tyre to overlap across the centerline when arranged in a series extending around the periphery of the tyre.

12. A tyre tread as claimed in claim 1 1 wherein the pattern is a herringbone pattern.

13. A tyre tread as claimed in any of claim 1 1 or claim 12 wherein the bars are located in slots in the base material of the tyre with their splayed ends engaged in slots extending from the outer side walls of the tyre to beyond the centerline of the tyre.

14. A tyre tread as claimed in any of claims 1 1 to 13 wherein the channel sectioned members providing the side walls of the bars are secured to the base rubber by fasteners extending from channel webs into the tread base material.

A tyre tread as claimed in any of claims 1 1 to 14 wherein the rubberlike material is a polyurethane composition and the channel sectioned members are made from steel.

16. A wheel assembly as claimed in any one of claims 1 to 6 in which the carcass of the tyre has a series of transversely extending passages therein with at least some of the passages having supporting ribs extending radially inwardly from their outer ends.

A wheel assembly as claimed in claim 16 wherein the ribs are centrally located in each alternate passage and the remaining passages extending alternatively from opposite sides of the carcass partway through the thickness of the carcass.