AU2004201973B2

AU2004201973B2 - Wheel assembly

Info

Publication number: AU2004201973B2
Application number: AU2004201973A
Authority: AU
Inventors: Christopher Ralph Burston; Sean Anthony Burston
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-05-13
Filing date: 2004-05-10
Publication date: 2011-03-31
Anticipated expiration: 2024-05-10
Also published as: AU2004201973A1

Description

P/101o1 Regulation 3.2 AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Invention Title: Wheel assembly The following statement is a full description of this invention, including the best method of performing it known to us: 1 WHEEL ASSEMBLY Field of the Invention The present invention relates to improved multi-wheel assemblies for heavy transport vehicles. In particular, the invention relates to a method of retrofitting an 5 existing wheel assembly with a modified design. Background to the Invention Demountable rims and wheels are commonly mounted in due configuration on rear axle(s) on heavy duty vehicles such as earth moving trucks and trailers typically used in the mining industry. There are also some applications, though 10 comparatively rare where the tyres in dual mounted configuration are found on front axles of heavy equipment. The current wheel and rim design as applied to a dual wheel/rim situation is shown in Figure 1. A segment of the rim base 10 is shown in cross section. The rim base 10 is made up of a front portion 12 a middle portion 14 and a rear portion 16. Each of these portions is formed by rolling and 15 machining and then the three portions are circumferentially welded together to form the finished rim base 10. A wheel disc can be welded onto the inner diameter of the rim base. The back portion 16 has a radially outer surface 18 which is ramped radially outwardly in the direction towards the rear edge 20. The rear edge 20 also has a 20 flange projecting radially outwardly. To provide additional support to the tyre, an annular flange 22 is provided. The diameter of the radially outer periphery of the rear edge 20 is greater than the inner diameter of the tyre wall. Accordingly, the rear tyre wall is not permitted to pass beyond the rear edge 20 as the outside of the rear tyre wall sits against and maintains an outward force on the annular 25 flange 22. At the front portion 12 of the rim 10, the radially outer periphery is provided substantially level with middle portion 14. The tyre 24 is assembled onto the wheel rim by being passed over the front portion 12 until the back wall abuts against the rear edge 20 indirectly through the annular flange 22. The front wall of the tyre 24 30 is held in position by the use of an annular bead seat band 26. The bead seat 2 band 26 has a ramped radially outer periphery with a peripheral flange 28 projecting radially outwardly. The bead seat band 28 is held in place by a lock ring 30. An annular flange 32 is also inserted between the front tyre wall and the peripheral flange 28. 5 In a dual wheel assembly, two such wheels or rims would be located side by-side, with the lock ring 30 of each wheel or rim adjacent the lock ring 30 of the other wheel or rim see (Figure 2). In order to change the tyre of the inner wheel or rim, it is necessary to remove the outer wheel or rim to gain access to the inner wheel or rim. To change the tyre of the inner wheel or rim, the tyre is deflated and 10 then the lock ring and bead seat band and flange are removed so that the tyre can be removed. Once the tyre has been changed, the flange 32, bead seat band 29 and lock ring 30 are returned, following which the outer wheel/rim can be returned to its position on the axle. For tyres mounted on demountable rims, deflation of both outer and inner tyre is required prior to loosening the cleat nuts for safety 15 reasons. To change the tyre of the outer wheel or rim, the wheel or rim must first be removed from the truck. Once removed from the truck it is normally placed horizontally on the ground, the tyre is first deflated and then the lock ring and bead seat band and flange are removed so that the tyre can be removed. Once the tyre 20 has been changed, the flange 32, bead seat band 28 and lock ring 30 are returned, the inner wheel/rim can be returned to its positions on the axle. For tyres mounted on demountable rims deflation of both outer and inner tyre is required prior to loosening the cleat nuts for safety reasons. The removal of the outer wheel rim to gain access to a tyre of an inner 25 wheel is time consuming. In particular, there are a large number of wheel nuts to be removed and later refitted from the outer wheel. When these wheel nuts are refitted, they are required to be retorqued to ensure adequate bond between the track axle and the wheel or rim. Furthermore, the lifting and removal of the outer wheel rim and later refitting has potential to damage the stud threads. 30 Furthermore, the mere task of lifting the very heavy outer wheel rim has associated risks.

3 One prior art solution has been presented in Australian patent application no. 200126561 (see Figure 3). This proposed solution involves reducing the size of the outer wheel rim so that the inner tyre may be slid over the outer wheel rim without having to remove the outer wheel rim. To compensate for the decreased 5 diameter in the wheel rim, thicker bead seat bands are used at both the front and the rear of the outer wheel rim. The different sizing of the outer wheel leads to introduction of additional parts including a new size for the wheel rim, a new sizing for the bead seat bands, the locking-ring and "0" rings. In any situation where it is desirable to keep quantities of replacement parts in stock, the introduction of yet 10 more parts in often remote locations and would seem to be a disadvantage. Fitting of heavy equipment tyres has recorded many fatalities, accidents and near misses that were caused by mismatching of wheel/rim assembly components, the introduction of an "O" ring, lock ring, bead seat band and flange arrangement of different dimension and having specific application would only seem to increase 15 the potential for mismatched components to be used with often tragic consequences. Accordingly, it is an object of the present invention to address at least some of the aforementioned disadvantages or at least provide the public with a useful choice. 20 Reference to any prior art in the specification is not, and should not be taken as, an acknowledgment or any form of suggestion that this prior art forms part of the common general knowledge in Australia or any other jurisdiction or that this prior art could reasonably be expected to be ascertained, understood and regarded as relevant by a person skilled in the art. 25 Summary of the Invention In accordance with a first aspect of the present invention there is provided a method of modifying a wheel assembly for a tyre, the wheel assembly including a wheel rim having a front portion, and a rear portion, the rear portion having a tyre engaging periphery which is ramped or stepped in a radially outward manner 30 towards the rear edge of the wheel rim to retain the tyre on the rim, and a 3a removable front bead seat band mounted over the front portion, the method including: removing the rear portion of the wheel rim; 4 connecting a replacement rear portion onto the remainder of the wheel rim, wherein the replacement rear portion has a radially outer projection to retain a removable rear bead seat band on the rim; and further providing the removable rear bead seat band having a radially outer 5 periphery which is ramped or stepped radially outwardly towards the rear edge of the wheel rim. The wheel rim may further include a middle portion. The front portion, middle portion and rear portion of the wheel rim may be connected by being welded together. The rear portion may be removed by 10 machining it from the remainder of the wheel rim. Likewise, the replacement rear portion may be connected by welding. The term "wheel assembly" is to be broadly construed to include rim types which have a wheel disc or knave plate attached to the inner circumference and to cover demountable rims without a disc. 15 In the context of the description and claims, the terms "front", "middle" and "rear", may be used to indicate portions of the wheel rim relative to the outside of the vehicle. In other words, the "front" faces the outer end of the axle such that it faces a maintenance person who is to remove the wheel rim or the tyre. In a similar manner, the term "outer" refers to the orientation relative to the vehicle so 20 that "outer" is close to the sides and the term "inner" means close to the longitudinal centreline of the vehicle. In contrast, where it is intended to mean the outer circumference of the wheel rim or tyre, the term "radially outer" or similar terms are used to distinguish from the term "outer" as set out above. The rear bead seat band is ideally of the same form as the front bead seat 25 band so that a common part may be used for both. The front bead seat band may be retained by a lock ring in contrast to the projection retaining the rear bead seat band. The rear bead seat band may be the standard bead seat band used for the particular tyre size. This means that the same kind of bead seat band may be used for modified wheel assemblies as would be used for unmodified wheel 5 assemblies, limiting the different number of parts which would be required. Alternatively, a radially expandable bead seat band may be employed. The replacement rear portion may further incorporate a peripheral groove to receive an O-ring seal. 5 The method of the present invention may also comprise removing the front portion of the wheel rim and replacing it with a replacement front portion having a radially outer projection to retain the front bead seat band. This change need not occur when the rear bead seat band is removed but may be implemented as the front section wears. The invention may also reside in a reversal of the method, 10 removing the front portion first. Where both front and rear portions of the rim have been removed, the invention can be implemented with radially expandable bead seat bands. Described herein, but not claimed, is a bead seat band for a wheel rim, wherein the bead seat band is radially expandable. 15 The bead seat band may comprise an annulus with a gap such that the bead seat band is expandable between a closed configuration whereby the gap is closed and an open configuration whereby the gap is open and sufficient to allow the bead seat band to pass beyond over the widest part of the wheel rim. Alternatively, the bead seat band may be provided in multiple portions, e.g. two 20 halves able to be fixed together. The expandable bead seat band may be incorporated into a multi-wheel assembly as described below, including: an outer wheel having an outer wheel assembly for an outer tyre, wherein the outer wheel assembly includes an outer wheel rim, a removable front bead 25 seat band such that the outer tyre may be removed from the outer wheel rim, and a removable rear bead seat band; and an inner wheel having an inner wheel assembly for an inner tyre, the assembly including an inner wheel rim and a removable front bead seat band 6 which is radially expandable and able to pass over the outer wheel rim, wherein the dimensions of the outer wheel rim are such that the inner tyre is able to pass over the outer wheel rim. The above arrangement may be implemented in a dual wheel assembly. 5 However, the invention is not so limited and may be applied to arrangements with three or more wheels on a single axle. In such an arrangement, each of the wheels other than the innermost suitably has radially expandable bead seat bands. Each of the radially expandable bead seat bands may be seated against a radially outward projection provided in the rim which is complementary to the bead 10 seat band. Preferably, the front bead seat band of the outer wheel has the same dimensions as the rear bead seat band. Furthermore, it is preferred that the front and rear bead seat bands are standard bead seat bands for the given tyre size. Preferably, the outer wheel rim and the inner wheel rim are of substantially the 15 same radially outer dimensions in the portions where the bead seat bands are seated. The front bead seat band of the inner wheel may be retained by a removable lock ring. Alternatively, the front bead seat band may be retained by a radially outwardly projection. Suitably, the dimensions of this projection are such 20 that the inner tyre is able to pass over the radially outer periphery of the projection. The inner wheel rim may be of a conventional configuration with an expandable front bead seat band held by a lock ring and an integral ramped back portion. Also described herein, but not claimed, is a method of assembling a multi 25 wheel assembly, the method comprising: providing an outer wheel assembly for an outer tyre; providing an inner wheel assembly for an inner tyre; the assembly including an inner wheel rim; 7 mounting the inner wheel rim on a vehicle axle, followed by the outer wheel assembly, wherein the outer wheel assembly includes an outer wheel rim and a removable front bead seat band such that the outer tyre may be removed from the outer wheel rim, and a removable rear bead seat band, and 5 wherein the inner wheel assembly includes a removable front bead seat band which is radially expandable and able to pass over the outer wheel rim wherein the dimensions of the outer wheel rim are such that the inner tyre is able to pass over the outer wheel rim. The inner and outer wheel assemblies may be of the form as set out in 10 accordance with the second aspect of the present invention. Also described herein is a method of removing the inner tyre of the multi wheel assembly without removal of the outer wheel rim by sliding the inner tyre over the outer wheel rim once the outer tyre and the radially expandable bead seat band have been removed. 15 Also described herein, but not claimed, is a wheel assembly for a tyre, the wheel assembly including: a wheel rim having an integral front radially outward projection and an integral rear radially outward projection; a front removable bead seat band seated against the front projection; and 20 a rear removable bead seat band seated against the rear projection, wherein the inner and outer removable bead seat bands are radially expandable bead seat bands able to pass over at least the front projection. As used herein, except where the context requires otherwise the term 'comprise' and variations of the term, such as 'comprising', 'comprises' and 25 'comprised', are not intended to exclude other additives, components, integers or steps.

8 This invention may also be said broadly to consistent the parts, elements, and features referred to or indicated in the specification of the application, individually or collectively and any or all combinations of any two or more of said parts, elements of features and where specific integers are mentioned herein 5 which have known equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth. The invention resides in the foregoing and also envisages constructions of which the following gives examples. 10 Brief Description of the Drawings In order that the invention may be more fully understood, some embodiments will now be described, by way of example, with reference to the drawings in which: Figure 1 is a cross-sectional view of a segment of a wheel rim with tyre 15 according to the prior art; Figure 2 is a schematic view of a prior art dual mount configuration; Figure 3 is a schematic view of a dual mount configuration according to the prior art; Figure 4 is a cross-sectional view of a segment of a wheel rim with tyre 20 according a preferred embodiment of the present invention; Figures 5, 5a and 5b are front and cross-sectional views of the bead seat band according to the prior art; Figures 6 and 6b are front and cross-sectional views of the bead seat band according to a preferred embodiment of the invention, the bead seat band being 25 illustrated in closed configuration; 8a Figures 7a and 7b are front and cross-sectional views of the bead seat band of Figure 6 shown in the open configuration; Figure 8 is a schematic view of adjacent wheel rims in a dual mount configuration incorporating the wheel rim illustrated in Figure 4; 5 Figure 9a illustrates the dual mount arrangement of Figure 8, together with appropriate bead seat bands and Figure 9b illustrates an alternative dual mount configuration; Figure 10a is a front view of a second preferred radially expandable bead seat band in open configuration; 10 Figures 10b and 10c are front and cross-sectional views of the bead seat band of Figure 1 0a in closed configuration; 9 Figure 11 is a schematic view of a segment of a wheel rim according to another preferred embodiment of the present invention; and Figure 12 illustrates a dual mount configuration utilising the wheel rim illustrated in Figure 11. 5 Description of the Preferred Embodiments Figure 4 illustrates a modified form of a wheel assembly. Many parts of the wheel assembly are similar to the prior art wheel assembly illustrated in Figure 1. Accordingly, like numerals represent like parts. The wheel rim assembly includes a wheel rim 40 which has three portions. 10 The front portion 12 and the middle portion 14 are of the same form as in the prior art. The back portion 46 of the wheel rim 40 is modified as shown in Figure 2. Furthermore, the components mounted on the front portion 12 are the same as the prior art shown in Figure 1 and like numerals represent like parts. Additionally, it will be seen that the front portion has two parallel grooves arranged 15 on the radially outer surface. These parallel grooves form dual gutters. The inner gutter (relative to the wheel rim) seats an O-ring. The outer gutter seats lock ring 30. The rear portion 46 is modified to no longer be provided with the gradually inclined ramped surface 18. Instead, the back portion has a web portion 48 20 presenting a radially outer surface that is substantially level with that of the middle portion 14. The rear portion 46 also has a peripheral rim 50 which includes integrally formed dependent rim portion 52 and radially outwardly projecting rim portion 54. The dependent rim portion 52 corresponds to the form of the dependent rim portion 13 formed at the front of the front portion 12. The radially 25 outwardly projecting rim portion 54 corresponds approximately to the form of the lock-ring 30 at the front of the front section 12. The two portions 52 and 54 are integrally formed as shown. This combined section which corresponds to the front section of the front portion (including lock ring 30) has been established for reliability and robustness by years of application in the field.

10 The back portion 46 also uses a rear bead seat band 26 which is in the same form as the standard bead seat band used on the front portion 12. A peripheral groove 56 is also formed adjacent the projecting rim 54 in which an 0 ring is seated to provide a seal. 5 Figure 5 illustrates the form of a prior art bead seat band 26. The diameter

D

1 mates with the diameter of the seat for the bead seat band on the rims 10, 40. The diameter D 2 is such that the tyre 24 is prevented from passing therebeyond, with the combined assistance of flange 32. Figures 6 and 7 illustrate a modified form of a bead seat band 60. The bead 10 seat band 60 is in the form of an annulus having a gap 62 provided therein as shown in Figure 7. Figure 6 illustrates the closed configuration whereby the gap 62 is closed through the use of a bolt/pin 64. An airtight seal is formed at the closed gap 62. The dimensions D 1 and D 2 correspond to those of the prior art bead seat band illustrated in Figure 5. In the expanded configuration of Figure 7, the internal 15 diameter of the bead seat band 60 is D 3 . Figure 8 illustrates a dual mount configuration with two wheel rims 40 as shown in Figure 4 disposed side-by-side. The diameter D 1 of the rims 40 where the bead seat bands are seated is D 1 , permitting seating of the bead seat bands 60 in the closed configuration. It can be seen that the diameter D 3 of the bead seat 20 bands 60 in the expanded configuration is sufficient to clear the projecting rim portions 54 as illustrated in Figure 8. Figure 9 illustrates two alternative arrangements for a dual mount configuration. In Figure 9a two modified rims 40 may be disposed side-by-side in the manner shown. In this arrangement, the two bead seat bands could be of the 25 conventional type 26 or the modified type 60. In this arrangement, for the inner rim, the outer bead seat band must be of the modified type 60 to enable it to clear the projecting rim portion 54. The outer bead seat band on the inner rim 40 can be either the conventional type 26 or the new type 60. Figure 9b illustrates an alternative arrangement for the inner rim using a 30 conventional type rim 10 as shown.

11 When it is required to change the inner tyre, the following procedure is used: . outer tyre is deflated, and the lock-ring 30, outer flange 32 and the front bead seat band 26/60 are removed; 5 . the outer tyre is then removed from the outer rim 40; . the rear bead seat band 26/60 and the peripheral flange 32 are then removed; . the inner tyre is deflated and its lock-ring 30 is removed and slid between the inner and outer wheel rims; 10 . the front bead seat band 60 of the inner wheel and the flange 32 is then removed and passed over the outer rim; . the inner tyre is slid off the inner wheel rim 40/10; . the inner tyre is slid over the outer wheel rim 40. Importantly, the radially outer diameter of the projecting rim 54 is such that 15 the inner tyre is able to pass thereover. Preferably, the diameter of projecting rim 54 is less than the diameter of the opening in the inner tyre. Figure 10 illustrates an alternative expandable bead seat band 70 comprising two halves 72, 74 which are separable to enable the bead seat band 70 to be removed. The two halves 72,74 include radial projections 76 enabling the 20 two halves 72,74 to be bolted together. Reconstruction of a prior art wheel rim to produce the modified wheel rim 40 will now be described. As already described with the prior art wheel rim in Figure 1, the prior art wheel rim is constructed of three portions, a front portion 12, a middle portion 14 and a back portion 16. Each of these portions is initially formed 25 prior to being welded together. It is proposed that the modified wheel rim could be constructed from a prior art wheel rim by removing the back portion 46 and rebuilding with a replacement back portion 46 as shown in Figure 4.

12 Additionally, the front portion 12 could also be removed and replaced with a replacement front portion 80 which is substantially the mirror image of replacement rear portion 46 as shown in Figure 11. These replacement portions 46, 80 can be replaced incrementally as each section wears out. 5 While the above describes a manner of modifying existing wheel rims, the new form of the wheel rim can be machined anew. Figure 12 illustrates a dual mount configuration utilising the modified wheel rims 82 as illustrated in Figure 11. In each case, the bead seat bands are of the expandable type 60/70 to enable the bead seat bands to pass over the projecting 10 rim portions 54. The foregoing describes only some embodiments of the present invention and modifications may be made thereto without departing from the scope of the present invention. It will be understood that the invention disclosed and defined in this 15 specification extends to all alternative combinations of two or more of the individual features mentioned or evident from the text or drawings. All of these different combinations constitute various alternative aspects of the invention. It will also be understood that the term "comprises" (or its grammatical variants) as used in this specification is equivalent to the term "includes" and 20 should not be taken as excluding the presence of other elements or features.

Claims

1. A method of modifying a wheel assembly for a tyre, the wheel assembly including a wheel rim having a front portion, and a rear portion, the rear portion having a tyre engaging periphery which is ramped or stepped in a radially 5 outward manner towards the rear edge of the wheel rim to retain the tyre on the rim, and a removable front bead seat band being mounted over the front portion, the method comprising: removing the rear portion of the wheel rim; connecting a replacement rear portion onto the remainder of the 10 wheel rim, wherein the replacement rear portion has a radially outer projection to retain a removable rear bead seat band on the rim; and further providing the removable rear bead seat band having a radially outer periphery which is ramped or stepped radially outwardly towards the rear edge of the wheel rim. 15

2. The method as claimed in claim 1 wherein the wheel rim further includes a middle portion and the rear portion is removed by machining it from the remainder of the wheel rim and the replacement rear portion is connected by welding.

3. The method as claimed in claim 1 or claim 2 wherein the rear bead 20 seat band is of the same form as the front bead seat band so that a common part may be used for both.

4. The method as claimed in any one of the preceding claims wherein the front bead seat band is retained by a lock ring.

5. The method as claimed in any one of the preceding claims wherein 25 the rear bead seat band comprises a standard bead seat band used for the particular tyre size. 14

6. The method as claimed in any one of the preceding claims wherein the rear bead seat band comprises a radially expandable bead seat band.

7. The method as claimed in any one of the preceding claims wherein the method further comprises removing the front portion of the wheel rim and 5 replacing it with a replacement front portion having a radially outer projection to retain the front bead seat band.

8. A method of modifying a wheel assembly for a tyre substantially as hereinbefore described with reference to figures 4 to 12 of the accompanying figures.