Description:FIELD OF INVENTION :

The invention relates to classic wired spoked wheels with a steel flanged rim design with “MT-Type” (ETRTO) rim contour for application with tubeless tyres.

BACKGROUND OF THE INVENTION :

The present invention relates to wheels, particularly wheels for motorcycles fitted with a tubeless tyre, although the disclosure is also on other types of wheel application. More specifically the invention relates to the rim design suitable for manufacture from steel with a radial flange protruding toward the rim with apertures to anchor the head of spokes which are secured at the hub to construct the wheel.

A motorcycle wheel consists of a bearing carrying hub, where spokes connect the hub to the rim which provides a channel to mount a pneumatic tyre. Cast or forged methods can be used to manufacture wheels with integrated spokes between the hub and rim, generally with this method the number of spokes is relatively low. Wire-spoked wheels have a significantly greater number of spokes which typically have a head formed on one end and an external tread formed on the other; further, nipples with internal threads are used to generate tension in the spokes between hub and rim. Different hub and rim designs use many alternate patterns of spoke arrangement and cater for spokes to be assembled with the thread and nipple portion either at the inner hub interface or at the outer rim attachment.

Traditionally rim designs had radial apertures in the well of the rim profile arranged around the circumference, often with dimple forms in the rim to cater for the attachment of spokes at an angle to the radial direction, with the nipple adjuster device located at the rim. These designs require initial assembly and spoke replacement to be carried out without a tyre fitted to the rim and use an inner tube to inflate the tyre or require rim sealing methods to realise the benefits of tubeless tyres.

Wheel designs with closed rim profiles for tubeless tyres are available which connect the spokes to; formed features in the rim, flange(s) or through the outer edge of the rim. These rims are generally manufactured from aluminium extrusions or forgings and as such are unsuitable for the economic requirements of a mass market cost sensitive product, particularly for regions with limited aluminium availability and processing capacity.

OBJECTIVE OF THE INVENTION

The primary objective of the invention is to provide a durable motorcycle rim which uses the MT-type rim contour that is suitable for tubeless inflatable tyres without any secondary sealing devices, which is possible to manufacture using steel and can accept a high quality corrosion resistant surface protection.

PRIOR ART :

A1 - US9290042B2 - Spoke Wheel (DID angles hole through flange)

A2 - US6425641B1 - Spoked cycle wheel (Easton bicycle flanged rim)

A3 - US9290042B2 - Spoke Wheel (for single sided swing arm)

A4 - WO2019161957 - Spoked wheel for tubeless tyres (BMW alternative, not flanged rim)
A5 - JP4357637B2 - Spoke wheels for tubeless tires (spokes to rim outer ‘Adventure’ Style)

One solution to the tubeless tyre problem on a steel wheel achieves a closed rim profile, without drilling for spoke attachment, by providing a flange protruding radially inward, see Fig. 1. This design is the subject of patent US 4266417A where it is formed from a continuous sheet material profile, and is also presented as a “Divided Rim for Miscellaneous Applications” in the European Tyre & Rim Technical Organisation - Standards Manual. This and other prior art solutions achieve a steel flanged rim with the closed tyre cavity but they do not deploy the MT-type contour necessary for correct tyre bead seating and tyre retention on the rim, particularly important on wider rims, greater than 3.0”.

Figure 1-A - A rim design; wherein the rim profile has a central flange, protruding radially inward providing a closed rim profile to the outer (upper in image) tyre cavity portion.

Figure -1-B - Rim design presented in patent US 4266417A.

Figure -1-C - Rim design in the European Tyre & Rim Technical Organisation - Standards Manual.

SUMMARY OF THE INVENTION

A rim design for a wire-spoked wheel to receive an inflatable tubeless tyre is provided with radially extending flange(s) from the centre of the rim protruding inwardly towards the hub. Spokes are assembled through and the spoke head located in axial holes arranged circumferentially around the flange. Each spoke being configured to bend adjacent to the flange connection inwardly towards the hub where the inner ends of the spokes, formed with an external thread, are each connected to an intermediate element inserted through and locating the hub. The rim is designed to enable manufacture from sheet materials, particularly rolled from steel. The specific novel aspect of the invention is the detail to achieve the “MT-type” (designated in the ETRTO; European Tyre & Rim Technical Organisation - Standards Manual) rim contour for the tyre interface required for application with tubeless type tyres particularly on rim widths greater than 3.0”.

DRAWINGS OF THE INVENTION :

Figure 2-A - A wheel design according to the invention; wherein the rim and hub are connected with numerous spokes with the spoke head anchored through the flange.

Figure 2-B - A rim design according to the invention with the MT bead present on the tyre facing side but not visibly identifiable from the inside.

Figure 3 - A flanged rim design with the tyre facing side using the standard ETRTO wheel contour (Not MT-Type), seam welds joint the mating horizontal portions under the tyre seat and a groove weld join and seal the leaks path where the flange portions meet.

Figure 4 - A rim design according to the invention; wherein the rim profile and flange is constructed from 1 continuous sheet with an annular MT-type bead formed between the drop centre and the seam welded tyre seat.

Figure 5 - A rim design according to the invention; wherein the rim profile and flange is constructed from 1 continuous sheet with an annular MT-type bead formed by an extension of the material from under the tyre seat and terminated before the centre.

Figure 6 - A rim design according to the invention; wherein the rim profile and flange is constructed from 1 continuous sheet with an annular MT-type bead formed by an extension of the material from under the tyre seat which continues to the rim centre.

Figure 7 - A rim design according to the invention; wherein the rim profile and flange is constructed from 2 pieces with an annular MT-type bead formed in the profile of the 2nd element, sealed with seam welds under the tyre seat area.

DESCRIPTION OF THE INVENTION

The present invention provides a wire-spoked wheel solution to the previously described issues relating to the use of tubeless tyres with the MT-Type contour using a sheet metal derived rim with a closed inner profile to the tyre cavity and an inward flange for spoke connection.

The air tightness is very important feature when tubeless tyres are installed on the wheels. Proper touch between rim and tyre ensures sealing the air inside the tubeless tyre.

The air tightness and exact fitting between tyre and rim are provided by bumps and recesses at the place where the tyre sits on the rim. This is referred as ‘rim profile’ and in accordance with the shape of rim flanges, rim flange contours or head profiles are designed.

The disclosed motorcycle wheel design comprises a central hub and tyre receiving rim connected with numerous wire-spokes. The proposed rim has radially extending flange(s) from its centre protruding inwardly towards the hub. The inner end of each spoke having an external threaded portion to connect with nipples which have internal threads located through holes in the hub, spoke tension and wheel from are generated by tightening the nipples. The spokes extend from the hub in a general radial direction to a circumference offset from the imaginary central plane of the wheel adjacent to the rim flange where the outer ends have a bend to protrude along the axial direction across the centre plane of the wheel. The spoke ends expand at an inclination angle to a head form of larger diameter and thus anchor through locating holes countersunk to one side and distributed around the circumference of the rim flange.

The disclosed rim constructed from sheet material is provided with a flange to avoid the convention of piercing in the well of the rim profile, to provide a closed channel for the tyre cavity. The flange is produced with adjacent portions of the rim material formed symmetrically about the centreline of the rim from the well of the rim profile protruding radially inwards. The rim profile may be joined and sealed between the said flange portions by use of a circumferential weld.

The disclosure specifically relates to design for the outer tyre facing portion of the rim to achieve the MT-type contour. The material forms the flange at the rim centre then extends symmetrically in the axial direction before bending outwardly to form the edge of the rim. The material is then bent with a radius profile inwardly and back towards the rim centre to leave a cavity in the rim section providing structure and strength to the rim as well as forming the wall which the tyre sidewall locates against. The material bends inwards towards the centre of the rim mating against the inner portion where the layers are seam welded together. This layered portion forms the innermost surface for the tyre to seat radially against and is at the 5 degree taper according to the MT-type ETRTO profile. The upper ply continues through another series of radius bends to form the MT bead portion which is just inside the tyre seat, further this returns inwardly again back into the dropped centre portion of the rim to facilitate tyre assembly onto the rim.

Alternatively to the upper ply continuing from the seam weld area is presented another design option where a separate sheet of material, potentially of thinner wall thickness, is layered above or between the other layers, described above, in the tyre seat seam weld. This piece of material spans the width of the rim joined in both seam welds and closed at its ends with another weld. This portion provides the bead following the MT-type contour.

The tyre inflation valve interface is achieved by either protruding through the rim inner layer at an angle to the radial direction between the flange and the tyre seat area, possibly with a local depression in or removal of the MT bead. Alternatively by mounting to a reinforcing inner plate protruding through the rim at its centre in a section with the flange removed. These options facilitate application across varying rim width.

The essential novel features are :

In one aspect, the invention relates to a rim design for wire-spoked wheels to receive an inflatable tubeless tyre where an enclosed cavity is formed between the tyre and the rim profile. Spoke connection is provided through radially extending flange(s) from the centre of the rim protruding inwardly towards the hub. The flange form being designed to enable manufacture from sheet materials, particularly rolled from steel with the application of the MT-type profile in the rim design.

In another aspect, the invention relates to the rim being formed of a single piece and the reverse of the MT bead is visible as a groove on rim once the tyre is assembled.

In another aspect, the invention relates to the rim being formed of a single piece and the ends of the material on the tyre facing side of the profile extend inwards to produce the MT bead, which is then not apparent after tyre assembly.

In another aspect, the invention relates to the ends of the profile forming the MT bead terminate between the bead and rim centre.

In another aspect, the invention relates to the ends of the profile forming the MT bead terminate adjacent to the rim centre and are included in the centre weld which seal the flanges.

In another aspect, the invention relates to the rim being formed of multiple pieces of material, with an additional annular ring being utilised to form the MT bead with necessary profile.

In another aspect, the invention relates to the additional piece being a thinner material than the main structural element of the rim profile.

In another aspect, the invention relates to the additional piece being sandwiched between the layers of the main structural element of the rim profile where they are seam welded on either side of the rim where the tyre seats.

In another aspect, the invention relates to the additional piece being joined on top of the main structural elements of the rim profile where they are seam welded on either side of the rim where the tyre seats.

In another aspect, the invention relates to the additional annular ring profile being included in the seam welds and thus closing the leak paths from the spoke attachments to the tyre cavity and as such a central weld is not required where the flange portions join.

Hence the invention is workable with many variations as detailed in few aspects described above but all intending to create an MT Type rim contour with sheet material and most preferably rolled from steel.

In one aspect the invention relates to a rim assembly for wire spoked wheels for receiving inflatable tubeless tyre comprising of a central hub. It has a rim having a plurality of protruding flanges extending radially from its centre and protruding inwardly towards the hub. It also has a plurality of spokes, extending from the rim and connected to the central hub, wherein the spokes extend radially from the hub towards the circumferential rim but which circumference is offset from the imaginary central plane of the wheel and adjacent to the corresponding rim flange, wherein the outer ends of the spokes have a bend protruding inwardly towards the hub, and along the axial direction and across the central plane of the wheel, which outer ends are expandable at an inclination angle to a head form of larger diameter and thus anchoring through locating holes countersunk on one side and distributed around the circumference of the rim flange. The arrangement is such that the flange forms a closed channel for tyre cavity and flange adjacent portions of the rim material formed symmetrically about the centre line of the rim from the well of the rim profile protruding radially inwards, thereby eliminating the conventional piercing in the well of the rim profile and further the rim profile is joined and sealed between said flange portions, the said arrangement is novel in the closed cavity formed by flanges between the tyre and rim profile.

In another aspect the invention relates to arranging the inner end of each spoke having an external threaded portion to connect with nipples which have internal threads located through holes in the hub, thereby enabling spoke tension and wheel form achieved by tightening the nipples.

In another aspect the invention relates to having the flange formed with sheet materials.

In another aspect the invention relates to having the rim is a single piece, wherein the ends of the piece on the tyre facing side of the profile extend inwardly to form the MT bead.

In another aspect of the invention, the ends of the piece forming the MT bead terminate between the bead and the rim centre and forms a portion of the centre weld which seals the flanges.

In another aspect of the invention, the rim is constructed of plurality of pieces including an annular ring profile forming the MT bead.

In another aspect of the invention, the annular ring is of thinner material than rim material and the annular ring is sandwiched between layers of rim structural element and seam welded on either side of the rim onto which tyre seats or alternatively the annular ring is jointed onto top of main rim elements and seam welded on either side of the rim wherein the tyre seats. Further the annular ring forms a portion of the seam welds, such that it closes the leak paths from the spoke attachments to tyre cavity and thereby central weld is eliminated wherein the flange portions are jointed.

In another aspect the invention relates to a wheel with a rim assembly as detailed herein and disclosed in the specification.

There are many benefits of the invention and few are narrated below :

Enabling tubeless tyre fitment offers its own benefits relating to puncture occurrence and management and provides greater choice with increased availability of tubeless products from tyre manufacturers and distributors.

Existing designs for tubeless applications are formed using aluminium extrusions or forgings. The use of rolled steel forms both increases the wheel's durability and reduces the economic impact of using tubeless wheels on a wheel design. Particularly in certain economic markets and regions.

The flanged design increases the stiffness of the wheel rim for improved durability and performance of both the wheel and tyre.

The MT contour is commonly used with the application of tubeless type tyres; it provides sealing benefits and improves location and seating of the tyre. Most tubeless type tyres are designed and optimised specifically for this rim profile.

The many aspects of the invention allow the use of the MT-type contour on steel sheet rims without any detriment to the appearance of the wheel once the tyre is assembled. The invention enables the use of the MT-type profile to be used on narrow rim widths.

It is submitted all variants as known in skilled person are within the scope of the invention.
, Claims:WE CLAIM :

1. A rim assembly for wire spoked wheels for receiving inflatable tubeless tyre comprising:

a central hub,
a rim having a plurality of protruding flanges extending radially from its centre and protruding inwardly towards the hub,
a plurality of spokes, extending from the rim and connected to the central hub, wherein the spokes extend radially from the hub towards the circumferential rim but which circumference is offset from the imaginary central plane of the wheel and adjacent to the corresponding rim flange,
wherein the outer ends of the spokes have a bend protruding inwardly towards the hub, and along the axial direction and across the central plane of the wheel, which outer ends are expandable at an inclination angle to a head form of larger diameter and thus anchoring through locating holes countersunk on one side and distributed around the circumference of the rim flange, and
wherein the flange forms a closed channel for tyre cavity and flange adjacent portions of the rim material formed symmetrically about the centre line of the rim from the well of the rim profile protruding radially inwards, thereby eliminating the conventional piercing in the well of the rim profile and further the rim profile is joined and sealed between said flange portions,
the said arrangement characterized in the closed cavity formed by flanges between the tyre and rim profile.

2. The rim assembly as claimed in claim 1, wherein the inner end of each spoke having an external threaded portion to connect with nipples which have internal threads located through holes in the hub, thereby enabling spoke tension and wheel form achieved by tightening the nipples.

3. The rim assembly as claimed in claim 1, wherein the flange is formed with sheet materials.

4. The rim assembly as claimed in claim 1, wherein the rim is a single piece, wherein the ends of the piece on the tyre facing side of the profile extend inwardly to form the MT bead.

5. The rim assembly as claimed in claim 4, wherein the ends of the piece forming the MT bead terminate between the bead and the rim centre and forms a portion of the centre weld which seals the flanges.

6. The rim assembly as claimed in claim 1, wherein the rim is constructed of plurality of pieces including an annular ring profile forming the MT bead.

7. The rim assembly as claimed in claim 6, wherein the annular ring is of thinner material than rim material.

8. The rim assembly as claimed in claims 6 and 7, wherein the annular ring is sandwiched between layers of rim structural element and seam welded on either side of the rim onto which tyre seats.

9. The rim assembly as claimed in claims 6 and 7, wherein the annular ring is jointed onto top of main rim elements and seam welded on either side of the rim wherein the tyre seats.

10. The rim assembly as claimed in claim 9, wherein the annular ring forms a portion of the seam welds, such that it closes the leak paths from the spoke attachments to tyre cavity and thereby central weld is eliminated wherein the flange portions are jointed.

11. A wheel with a rim assembly as claimed in claim 1.