The invention has particular application to tyres of larger size of the type that are used in large machines for applications such as earthmoving so that the tyres themselves are used firstly at relatively low speeds such as to a maximum of 12- 15mph and in circumstances where they can be vulnerable to impingement or fracture by reason of being impinging or being torn by rocks or other incidental encountered debris.

The costs associated with firstly repairing tyres of current design from such incidental encounters can be very high and furthermore, there are additional costs while the machinery for which the tyre is to be used is being stood down during such replacement or repair.

An object of this invention is to provide both a method and means and a resulting product which can assist in reduced costs associated with tyres in such applications.

SUMMARY OF THE INVENTION In one form of this invention there is proposed a method of producing a tyre which includes the step of introducing into a tyre casing a resilient matrix which is then positioned between a tube or a retained supply of air at pressure and the tyre casing.

In a further form of this invention there is proposed a tyre having therein a resilient matrix which is then positioned between a tube or a retained supply of air at pressure and the tyre casing.

In preference the resilient matrix is positioned to extend between an inner surface of a tyre casing and a contained volume of air at pressure in the manner of an inflated inner tube or air contained by a membrane being held in sealing engagement with a rim in the manner of a tubeless tyre.

The resilient matrix in preference can be comprised of particles of a resilient material held by a binder.

In preference, the resilient particles are fragments of material derived from tyre casings where such previous tyre casing has had removed therefrom such particles.

In preference, the resilient matrix is comprised of a composite of particles scoured from existing tyres which particles are then bound together by a resilient material and formed into a shape or segment that will together with other shapes or segments of resilient matrix provide the infill.

In preference, such segments can be of a shape and size so as to be readily handled for insertion within a casing, and can be of such a size that in a first position they will locate to be positioned between an inner rim of a tyre casing but then be rotated to effectively engage against all of the inner surface of a portion of a tyre casing.

In preference, each such segment allows for an area within which there can either be a sealing membrane or that there can be an inner tube so that upon subsequent inflation, the infill can then be effectively compressed for use when the tyre is to be used.

The above describes a tyre and a method of producing a tyre which includes the step of introducing into a tyre casing, a resilient matrix which is then positioned between a tube or a retained supply of air at pressure and the tyre casing. The resilient matrix which includes a composite of particles scoured from existing tyres which particles are then bound together by a resilient material and formed into a shape that will together with other shapes of resilient matrix provide the infill.

In a further aspect of the invention there is proposed an improvement to the arrangement described which, in addition to the method previously described, includes the step of introducing into a tube, a matrix material which is forced into the tube under pressure and is then held within the tube.

In preference, the matrix is introduced into the tube and maintained in the tube under pressure while a binder sets so as to hold the matrix in a retained position within the tube.

In a further form of the invention there is proposed a tyre having therein a resilient matrix which is then positioned within the tyre and tyre casing and wherein a matrix is pumped into any remaining space there in-between.

The advantage of such an arrangement is that a tyre constructed in the manner now described is relatively protected against any form of deflation of the tube.

The tube in the first instance is used to guide and effect a full internal pressure expansion within a tyre and the material which is inserted into the tube, is chosen and pushed in so that the material itself will exert this substantial pressure.

In preference said material within the tube can be re-used as segments in other tyres.

The matrix material proposed is threaded materials derived from previously formed tyres and it therefore has implicit resiliency by reason of curled shape and by reason of the natural resiliency of the material being recovered from previous tyres.

Further, if this material is thoroughly mixed with a binder that, as a matter of time after insertion will set although maintain a binding between the respective particles of the matrix, then once this has set, the tube itself will not be any longer vulnerable to deflation.

In fitling a tube and infiating this with the matrix material under pressure, a conventional tube of the type conventionally used in tyres can be used with an appropriate inlet valve and in preference an air outlet as the material is inserted into the tube from one point where the tube itself is of generally donut shape.

To some extent, the filling process will expand the resilient rubber material of the tube and to some further extent, will expel air through an air vent appropriately located.

While the tube has been described to guide the matrix as it is being pumped in more or less semi-fluid way, it is considered possible that other forms of guide can be used which are not tubes as such but which will allow for receipt of the matrix as it is being pumped into a cavity within a tyre and where the tyre includes an outer casing, and a plurality of segments interlocking together where each of the segments is comprised of recovered material gauged from previous tyres, and held together by an appropriate binder, leaving however a core tubular shaped area which can be directly filled under pressure with a matrix to be left and set in the manner described.

BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of this invention, several embodiments will now be described with the assistance of drawings wherein: Figure 1 is a perspective view of a tyre with part cut away in accord with a first embodiment; Figure 2 is a perspective view of a resilient matrix segment as used in the first embodiment; Figure 3 is a further perspective view of a resilient matrix segment as used in the first embodiment; Figure 4 is a cross sectional view of a tyre along the lines of 2-2-2 in Figure 1; Figure 5 is a plan view of the first embodiment; Figure 6 is a cross sectional and exploded view of a further tyre according to a further embodiment; Figure 7 is a cross sectional view of the second embodiment in an assembled form; Figure 8 is a cross sectional view of the second embodiment with the tube having been inflated; Figure 9 is a cross-sectional view showing the tyre casing, a wheel rim, intermediary segments made from a matrix material within the casing but on the outside of the tube, and a tube being filled; Figure 10 illustrates the same view as in Figure 9 with the filling completed and where there is now some applied pressure; Figure 11 is a perspective view of a tyre with part cut away in accord with a third embodiment ; Figure 12 is a perspective view detailing the segments used in the third embodiment prior to being covered with a plastic film;

Figure 13 is a perspective view of a segment of the third embodiment after being covered with a plastic film; Figure 14 is a perspective view of a tyre with part cut away in accord with a fourth embodiment; and Figure 15 is a perspective view if one of the segment used in the fourth embodiment.

BEST MODE OF THE INVENTION Referring in detail to the drawings and in particular to Figure 1 through to 5, there is a tyre casing 10 of a conventional type providing however an inner surface 12 which if used normally would conventionally be filled fully with an inner tube 14 which would be inflated.

In accordance with this invention then, the casing 10 has located in it infill segments 16 which are a resilient matrix comprised of particles of rubber as well as other materials derived by scouring or scraping existing tyre casings.

Such a scouring or scraping is effected by dragging a cutting tool across the surface of a tyre casing material at a speed that is such as to scoop from the tyre casing a slither of rubber which however will not unduly cause heating of the material and hence burning or other degradation of the material during the process.

This then leaves a plurality of particles of coiled and varied shape together with reinforcement within the tyres such as nylon fibres which together perhaps form a proportion by displacement volume of 50% of rubber or rubber compound and 50% of nylon reinforcing fibre.

This description of the proportions is given to illustrate the type of materials that can thus be extracted but is not intended in any sense to be comprehensive in its description except to say that one can obtain such materials in this way which serve the purpose of the invention.

The materials so scoured from tyre casings are then mixed with a binder which mixture is then formed into the segments 16 each of which, in an interlocking manner, are inserted sequentially within the existing tyre casing 10.

Such an infill then is provided by a number of separate segments 16 each of which includes a cavity 18 which thereby facilitates insertion therein of an inner tube 14 which when inflated then will further compress the resilient matrix formed in the manner described.

In the first embodiment then, the segments 16 are divided with sides located at spaced apart locations around the periphery of the casing 10 so that each segment 16 occupies a selected space so that a plurality of such segments 16 will collectively substantially fill in a full casing area.

However, there would then be left a smaller area which is moulded by inserting therein material to be moulded in situ by jamming such material into any gap remaining leaving however the cavity shape to maintain as fully extending around the tyre this cavity to have located therein the inner tube 14.

A first significant advantage of the arrangement is that materials which have formally been considered to be of negligible commercial value can now be used to significantly assist in extending the life of existing tyres.

While the addition of the infill would make such tyres vulnerable to increased heat over a higher range of speeds, it has been found with lower speeds that with such an infill it does not so cause excessive heating to the stage of causing damage to the tyre and hence is able to be accepted with tyres especially where these are to be used at lower speeds typically at 15mph or lower.

This is not to say that the tyres could not be used for speeds higher than such a speed but other means for keeping the temperature cooler may have to be considered or the use of the tyres might have to be only on smaller bursts of higher speed where the temperature build-up will not be sustained over an unduly longer period.

Each segment 16 then is in a form having on respective sides shown typically at Figures 2 and 3 a planar shape at 20 and 22 and these respective planar shapes are aligned to follow a radius of the tyre casing 10 as shown especially in Figure 5.

Further, each segment 16 has an outer surface shape other than at the planar sides such that this shape will conform to an inner shape of the casing so that it is generally of arcuate convex shape as shown at 24 then is concave at 26 and 28 to provide therefore a segment of U shape with legs between which a closure member 30 will be located..

In the second embodiment shown in Figure 6 through to 8, the segments are each divided transversely into three separate parts 32,34 and 36. These segments then are each somewhat lighter individually than the segments in the first embodiment and are therefore easier to handle. Also they can be inserted into an inner tyre space 38 more readily. The segments in this case are also however divided radially with planar faces on each side which are aligned with the radius of the tyre casing 40. Fitting of the segments involves each being hand located until most are fitted and then as necessary, filling a remainder of the tyre shape in the same alignment as the segment with the matrix.

When the tyre tube is inflated then, the matrix will compress as is shown in Figure 8. This then provides a significant increase in an effective wall thickness for the casing with a maintained resilience. Further, the cost of such a modification can be significantly less than the cost of a replacement tyre or a tyre having such addition casing thickness. To assist in preventing the tube 14 from sticking to the rim 42, a layer of suitable material such as thin plastic film 44 may be positioned between the tube and the rim.

Referring to Figures 9 and 10 there is shown a tyre casing 10 being of conventional form and, while it is not specifically shown it would be expected to include appropriate wire rubber reinforcing and fabric reinforcement and would be made from the same neoprene type rubber or other rubber materials or rubber like materials that tyres are made from. A plurality of inserts which are initially formed from tyre materials gauged from existing tyres and this is in accord with previously described methods and includes a segment 32 and secondly segments 34 and 36 which together provide for an interlocking shape in which a tube 14 can be located.

The tube 14 is made again in accord with conventional materials of which tubes are normally made for tyres, but in this case has modified in that valves and an air vent, these shown respectively at 46 for the inlet valve and 48 for the air vent.

What is done then is that the material shown at 50 is pumped into the tube 14 under sufficient pressure so that the tube itself will expand from the shape generally as shown in Figure 7 and so that their air is being displaced will be exiting from one or more air outlets such as is shown at 48.

The location of the air outlets will depend upon the size of the tyre overall, the relative position of the inlet as compared to the outlet so that as the material is pumped in, the last air will still be accessing an air outlet valve and such that the material being pumped in will be able to adequately flow into the areas where it is required.

The matrix material 50 is simply a mixture of gauged tyre chips which of their basic nature can be curled and therefore are inherently springy when pressed together as well as an appropriate binder which is mixed in the first instance and will then, either by reason of a matter of time or by, to some extent, applied heat, will commence curing and eventually cure to set relatively solidly the material pumped into the tyre.

In a further instance the fill material is expanded polyurethane plastics material.

Once the material has been set, the tube 14 forms less of a function.

As a result of this arrangement, a tyre can be substantially invulnerable to stake or rock damage insofar that it will cause deflation of an inner tube.

Further, there is the significant advantage that the tyre will no longer"burst"if damaged with possible collateral injury to people.

In the third embodiment illustrated in Figures 11 to 13, in some circumstances an inner tube is not needed and one can very well use a tubeless tyre. Under those conditions the segments 52 are also inserted sequentially into existing tyre casing 10, but do not include an inner cavity. The segments are rather of a solid block type arrangement whose shape is that similarly correspondingly shaped to the inner shape of the tyre casing.

To further compress the segments once the casing is mounted on a rim and effectively sealed, material is pumped into the tyre under sufficient pressure so that the segments will be further compressed. Said material will also be caused to flow in between and around said segments to further assist in maintaining the shape of the tyre. As in the case of the tyre tube, the location of the inlet and outlets will depends on the size of he tyre overall, and the relative position of the inlet as compared with the outlet.

By using solid segments without an inner tube, the construction of the tyre is greatly simplified. To further ensure that the segments are re-usable. A thin film 54 protects each of the segments from being adhered to the material when it solidifies.

Typically the film may be a plastic type material. It may either simply be wrapped

around each segment or alternatively may be heat-shrinked to ensure a good seal.

The second embodiment of the present invention used a material to fiEl in the inner tube 14 and which then solidifies to provide a resilient matrix. As seen in the fourth embodiment of the invention in Figure 14 and 15 the material held within the inner tube may itself be recycled. Generally the diameter of the inner tube is tess than the diameter of the tyre ad for that reason the material within the inner tube is more appropriately used in smaller diameter tyres.

Once an existing tyre needs to be recycled, the tyre is cut or opened to allow for the extraction of the inner tube and the materiel contained therein. The material, which is in the shape of a torous, is then cut into segments 56 and is again inserted sequentially into tyre 10. The shape of the segments are generally circular in shape.

To therefore assist in the segments being used in tyres, a groove 58 is cut into the back of each segment. When assembled within the tyre, the grooves all co-align and enable material to flow behind and in between the segments as it is pumped into the tyre under pressure.

This results in essentially the inside of the tyre to be completely filled with a strong and resilient material which can be subsequently be used again and again.

The number of individual pieces that the torous needs to be cut into depends on the geometry of the torous and the tyre. In some cases the matrix may be divided into eight or more equal segments.

A first significant advantage of the arrangement is that materials which have formally been considered to be of negligible commercial value can now be used to significantly assist in extending the life of existing tyres.

The method is of assistance both in connection with new tyres and in relation to older tyres where these might have been damaged but can be treated in accordance with this method so that they can continue to provide a useful life.

The type of tyres that are generally being discussed are those that are appropriate for very large machinery.

In such cases, the cost of tyres are very large indeed and a method such as that described will be of very significant advantage in being able to both reduce the chance of some damage to the tyre, reducing its working capability, and allowing reconstitution of existing tyres for a longer working life.

Accordingly, the invention is of significant advantage.

While the invention has been described in terms of a preferred embodiment, the person skilled in the art will appreciate the various modifications, changes and substitutions which may be made without departing from the scope of the invention. The descriptions of the subject matter in this disclosure are illustrative of the invention and are not intended to be construed as limitations upon the scope of the invention.