BACKGROUND OF THE INVENTION Wheeled vehicles which operate in rough terrain are often fitted with solid tyres to avoid the problems associated with puncturing conventional inflatable tyres. The types of vehicles fitted with solid tyres include fork-lifts, scissor-lifts, bobcats, trolleys, trucks etc. Solid tyres can be fitted to either a split type wheel rim or to a lock ring type wheel rim. A split type wheel rim has two halves which fit on either side of the tyre. The two split rim halves are pressed through the tyre towards each other and then fixed together. Fixing is generally by means of a plurality of nuts and bolts.

A lock ring type wheel rim is designed to pass through the tyre and the tyre is locked into place by locking rings (which may be 2, 3 or 4 pieces) which fit under a lip in the rim and bear against the side wall of the tyre.

In both cases the assistance of a tyre press is required. In the case of a split rim - to press the two halves of the rim together and, in the case of a lock rim - to compress the side wall of the tyre to allow the locking rings to be fitted under the lip in the rim.

Presses of the prior art are generally large and can include a structure of substantial size in comparison to the size of the tyre to be fitted to the wheel rim.

As a result of their relative size the structures are cumbersome and generally not convenient to transport. Furthermore some presses are specific for a particular wheel size and as such those presses are not suitable for other sized wheels.

The present invention seeks to overcome these disadvantages of the prior art by providing apparatus which is compact and may be used for fitting a range of sizes of tyres to a range of sizes of wheel rims on site.

The present invention also seeks to provide an apparatus which protects the wheel rim during the process of fitting the tyre to the wheel rim.

SUMMARY OF INVENTION According to one aspect of this invention there is provided an apparatus for use in fitting a tyre to a wheel rim including: a base member; an actuating means associated with the base member; a pull jig connectable in use to the actuating means; and a protecting means for protecting the wheel rim and positionable in use adjacent the base member.

Wherein in use the wheel rim and tyre are positioned between the base member and the pull jig and the actuating means operates to pull the pull jig towards the base member fitting the tyre to the wheel rim and the protecting means protects the wheel rim during the operation of the actuating means.

As this apparatus uses a pulling rather than pressing motion to fit the tyre to the wheel rim it is not necessary for the apparatus to include a substantial structure from which a press can be mounted. Instead it is only necessary to provide a base member towards which the wheel rim and tyre can be pulled.

Furthermore this apparatus provides the wheel rim with protection while the tyre is being fitted to the wheel rim.

It is preferred that the actuating means includes a ram positioned on a side of the base member, a pull rod extending from the ram out an opposite side of the base member for engagement by the pull jig wherein in use the wheel rim is positioned relative to the pull rod so the pull rod extends through an opening in a central portion of the wheel rim. Having the actuating means extending through a central portion of the wheel rim avoids limiting the apparatus to use with a wheel of a specific configuration.

It is still further preferred that the pull jig includes a female screw thread and the pull rod includes a threaded portion having a male screw thread with the pull jig being adjustable along the length of the threaded portion by screw mounting the pull jig onto the threaded portion. This permits the pull jig to be

adjusted along the threaded rod to bring the pull jig proximate the tyre and rim before the ram operates thus making more efficient use of the movement of the ram.

Preferably the pull jig includes three arms extending from a central portion of the pull jig with the female thread located at the central portion. This arrangements makes the pull jig suitable for use with tyres and wheel rims of varying diameters.

It is still further preferred that the protecting means spaces the wheel rim from the base member to prevent the wheel rim from being crushed into the base member during the operation of the actuating means. Spacing the wheel rim from the base member stops the wheel rim from being damaged by inappropriate contact with the base member.

It is still further preferred that the protecting means include a metal portion and an elastomer portion wherein in use the metal portion is positioned adjacent the base and the elastomer portion is positioned adjacent the wheel rim.

Preferably the metal portion is steel and the elastomer portion is a synthetic rubber. By this arrangement the metal portion provides support to the protecting means whilst the elastomer portion can cushion the force caused by the movement of the actuating means from the extended to retracted position.

In one preferred embodiment the wheel rim is a split wheel rim formed from a first half split rim and a second half split rim wherein in use fitting the tyre to the split wheel rim includes positioning the first half split rim adjacent the protecting means with the tyre positioned between the first half split rim and the second half split rim, wherein the pull jig engages the second half split rim with the actuating means pulling the pull jig and the second half split rim towards the first half split rim so that the first half split rim and second half split rim can be fixed together.

It is still further preferred that a protecting pad be positionable in use between the protecting means and the first half split rim to protect the protecting means when in use.

It is still further preferred that the first half split rim and second half split rim are fixed together using a plurality of nuts and bolts wherein in use the heads of the bolts engage the surface of the protecting pad to facilitate tightening of the

nuts on the bolts. By this arrangement the heads of the bolts dig in to the protecting pad so that the bolts cannot spin when the nuts are being tightened on the bolts. Furthermore it is envisaged that the protecting pad be independent from the protecting means so that the protecting pad may be replaced when worn.

It is still further preferred that a split rim jig be positioned in use between the pull jig and the second half split rim to facilitate pulling of the second half split rim towards the first half split rim.

Alternatively in another preferred embodiment wherein, the wheel rim is a lock ring wheel rim wherein in use fitting the tyre to the lock ring wheel rim includes positioning the lock ring wheel rim adjacent the protecting means, positioning the tyre between the lock ring wheel rim and the pull jig with the actuating means pulling the pull jig to bear against the tyre compressing the tyre to permit a locking ring to be fitted to the lock ring wheel rim.

It is still further preferred that a lock ring jig be positionable in use between the pull jig and the tyre to facilitate compression of the tyre.

It is still further preferred that an extension means associated with the pull jig be positionable in use between the pull jig and the lock ring jig to further facilitate fitting of the lock ring to the lock ring wheel rim.

It is still further preferred that the lock ring is to be formed from 2, 3 or 4 parts.

It is still further preferred that the tyre be a solid tyre.

According to another aspect of the invention there is provided a method for fitting a tyre to a wheel rim using apparatus including a base member, an actuating means associated with the base member, a pull jig connectable to the actuating means and a protecting means for protecting the wheel rim wherein said method includes the following steps: positioning the protecting means between the base member and the wheel rim; positioning the tyre adjacent the wheel rim; connecting the pull jig to the actuating means so that the protecting means, wheel rim and tyre are between the pull jig and the base member;

operating the actuating means to pull the pull jig towards the base member to fit the tyre to the wheel rim. This method permits the tyre to be fitted to the wheel rim while the wheel rim is being protected.

It will be convenient to describe the invention in greater detail by reference to the attached drawings which show one example embodiment of the invention.

The particularity of these drawings and the related description is not to be understood as superseding the generality of the claims defining the invention.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a transverse sectional view of an apparatus according to the invention shown assembled for use in fitting a tyre to a split wheel rim.

Figure 2 is a transverse sectional view of the apparatus of Figure 1 shown assembled for use in fitting a tyre to a lock ring wheel rim.

Figure 3 is a side view of the apparatus illustrating the hydraulic ram.

Figure 4 is a perspective view of the base member and pull rod.

Figure 5 is a perspective view of the assembly shown in Figure 4 further including the rim base jig and the first half split rim.

Figure 6 is a perspective view of the assembly shown in Figure 5 further including the tyre and second half split rim.

Figure 7 is a perspective view of the assembly shown in Figure 6 further including the split rim jig and the pull jig ready for use in mounting the tyre on the split rim.

Figure 8 is a perspective view of the apparatus of Figure 2 illustrating the locking rings ready for placement on the lock ring wheel rim.

Figure 9 is a perspective view of the assembly of Figure 8 with the pull jig and locking ring pull jigs removed illustrating the locking rings in position locking the tyre onto the lock ring wheel rim.

DETAILED DESCRIPTION WITH RESPECT TO THE DRAWINGS In the drawings is shown apparatus 1 for fitting a tyre 27 to a wheel rim.

Figure 1 illustrates a first preferred embodiment of the invention with the apparatus 1 fitting a tyre 27 to a split wheel rim including a first half split rim 20

and a second half split rim 21. Figure 2 illustrates a second preferred embodiment of the invention with the apparatus 1 fitting tyre 27 to a lock ring wheel rim 24. The apparatus common to both preferred embodiments is best illustrated in Figure 3.

Referring now to Figure 3 there is shown a base member 2 which according to the illustration extends in a substantially horizontal plane. It should be appreciated however that the base member 2 may extend in a plane other than a horizontal plane. A ram 3 is located on the underside of the base member 2. The ram 3 is operated by means of an hydraulic pump 6 which is air operated to 10,000 psi and feeds oil under pressure to the ram 3 along an hydraulic line 4.

A compressor 7 provides compressed air to operate the hydraulic pump 6 and also provides compressed air along the air line 5 to return the ram 3 to an extended position after use.

The combination of the ram 3 and pull rod 8 are referred to as the actuating means. The ram 3 operates to move the pull rod 8 between an extended position and a retracted position.

A pull rod 8 extends from the ram 3 through the base member 2 out from an upper side of the base member 2. The pull rod 8 includes a threaded portion 10 which is joined to a non threaded portion of the pull rod 8 by a joint 9.

The apparatus 1 also includes a pull jig 16 which is connectable to the pull rod 8. The pull jig 16 includes three arms which extend from a central portion of the pull jig 16. The central portion of the pull jig 16 includes a female thread to engage the threaded portion 10 of the pull rod 8. This arrangement permits the pull jig 16 to be adjustable along the length of the threaded portion 10.

Referring now to Figures 4, 5, 6 & 7 which in that order illustrate the fitting of a tyre 27 to a split ring wheel rim. Figure 5 illustrates a protecting means 11 positioned adjacent the base member 2 with the pull rod 8 extending through an aperture in a central portion of the protecting means 11. The protecting means 11 includes a metal portion 28 and an elastomer portion 29 with the metal portion 28 being positioned adjacent the base member 2. The metal portion 28 provides the protecting means 11 with support whilst the elastomer portion 29 provides the protecting means 11 with a cushioning effect.

The first half split rim 20 is positioned adjacent the protecting means 11 with the pull rod 8 extending through an aperture in a central portion of the first half split rim 20. A plurality of bolts 22 extend through bolt apertures in the first half split rim 20.

Referring now to Figure 6, the tyre 27 is positioned adjacent the first half split rim 20 with the pull rod 8 extending through an aperture in a central portion of the tyre 27. The second half split rim 21 is positioned adjacent the tyre 27 with the pull rod 8 extending through an aperture in the central portion of the second half split rim 21. The second half split rim 21 also includes bolt apertures which are aligned to receive the bolts 22 extending from the first half split rim 20.

Referring now to Figure 7 which illustrates a split rim jig 15 which is positioned to engage the second half split rim 21. The pull jig 16 is connected to the threaded portion 10 of the pull rod 8 and is adjusted along the length of the threaded portion 10 so as to engage the split rim jig 15. Once the pull jig 16 engages the split rim jig 15 the ram 3 of the actuating means operates to pull the pull jig 16 to a retracted position.

Figure 1 best illustrates the pull jig 16 in the retracted position whereby the first half split rim 20 and the second half split rim 21 make contact with each other. In this position nuts 23 can engage the bolts 22 to fix the first half split rim 20 to the second half split rim 21. To facilitate this process a protecting pad 13 is positioned between bolt heads of the bolts 22 and the protecting means 11. The bolt heads can engage the protecting pad 13, without damaging the protecting means 11, to resist the torque applied to the bolts 22 when the nuts 23 are being tightened.

Figure 1 also best illustrates the protecting means 11 spacing the first half split rim 20 from the base member 2. The spacing offers protection to the first half split rim 20 which otherwise may be crushed by the movement of the pull jig 16 to the retracted position.

Referring now to Figures 8 and 9 which illustrate the tyre 27 being fitted to the lock wheel rim 24. The earlier steps not illustrated are substantially identical to those performed with the split wheel rim, namely positioning the metal portion 28 of the protecting means adjacent the base member 2 with the elastomer

portion 29 positioned to receive the lock wheel rim 24, where after the tyre 27 is positioned adjacent the lock wheel rim 24.

The pull jig 16 is fitted with extension means 17 which in conjunction with a lock ring jig 14, which is positioned between the extension means 17 and the tyre 27, are brought to engage the tyre by adjusting the pull jig 16 along the threaded portion 10. The actuating means then operates to compress the tyre 27 to facilitate fitting a lock ring 25 under a lip 26 in the lock wheel rim 24. Having fitted the lock ring 25 the tyre is fitted to the lock wheel rim 24.

Compression of the tyre is best illustrated in Figure 2 which also illustrates the spacing of the lock wheel rim 24 by the protecting means.

The invention described herein is susceptible to variations, modifications and/or additions other than those specifically described and it is to be understood that the invention includes all such variations, modifications and/or additions which fall within the spirit and scope of the appended claims.