WO2006064444A1

WO2006064444A1 - Run-flat devices for wheel rim

Info

Publication number: WO2006064444A1
Application number: PCT/IB2005/054174
Authority: WO
Inventors: Michael Neville Wilkins; Andrew Webb
Original assignee: Michael Neville Wilkins; Andrew Webb
Priority date: 2004-12-15
Filing date: 2005-12-12
Publication date: 2006-06-22
Also published as: ZA200510107B

Abstract

A run-flat device (10) for a vehicle wheel includes an annular band body or obstruction body (12) which can be fitted to a vehicle wheel to obstruct a circumferentially extending well of the vehicle wheel. The band body (12) includes at least one part-annular strip (14) and a pair of radially inwardly projecting ribs (16) fast with the strip (14) for engaging a vehicle wheel to space the strip (14) from the wheel. The ribs (14) are located closer to one circumferentially or part- circumferentially extending edge (34) of the strip (14) than to the other axially or transversely spaced circumferentially or part-circumferentially extending edge 36) of the strip (14) .

Description

RUN- FLAT DEVICES FOR WHEEL RIM

THIS INVENTION relates to run-flat devices for vehicle wheels.

The use of run-flat devices to prevent or inhibit dismounting of a deflated pneumatic tyre from a vehicle wheel rim is well known. It is however a fact that various vehicle or wheel manufacturers provide rims that, even though they are of the same size, have wheel wells which are of different dimensions. A run-flat device that will fit on a particular vehicle wheel or rim will thus often not fit on a vehicle wheel or rim provided by a different manufacturer, even though the wheels or rims are of the same size. It would thus be advantageous to have a run-flat device which is more likely to be capable of being fitted to different vehicle wheels or rims.

According to the invention, there is provided a run-flat device for a vehicle wheel, the run-flat device including an annular band body or obstruction body which can be fitted to a vehicle wheel to obstruct a circumferentially extending well of the vehicle wheel, the band body including at least one at least part-annular strip and a radially inwardly projecting spacer fast with the strip for engaging a vehicle wheel to space the strip from the wheel, the spacer being located closer to one circumferentially or part- circumferentially extending edge of the strip than to another axially or transversely spaced circumferentially or part-circumferentially extending edge of the strip.

In this specification, the relevant axis when reference is made to "axially" is the centre axis of rotation or polar axis of the run-flat device which in use will thus correspond to the axis of rotation of a vehicle wheel. Also, "transversely" means in a direction parallel to said centre axis of rotation.

Typically, the spacer comprises a pair of circumferentially or part- circumferentially extending ribs or legs which are integral with the strip, the ribs being more or less parallel and being axially or transversely spaced, e.g. by a distance of about 15.5 mm.

The band body typically includes a pair of the part-annular strips which, when fitted together end to end, define an annular body. Each part-annular strip may thus form part of a band element. The two band elements are thus connectable to one another and the band body or obstruction body may thus include connectors connecting the band elements.

In one embodiment of the invention, the band elements are hingedly attached to one another at one end, and provided with connectors at their other ends.

The spacer divides the strip into two flanges or lips of which a broader one thus has a longer axial dimension or width than the other, narrower flange or lip, the flanges or lips typically being of substantially constant width. Preferably, the axial dimension or width of the broader flange or lip is at least about 1 .5 times, more preferably at least about 1 .75 times, most preferably at least about 1 .9 times, e.g. about 1 .92 times the axial dimension or width of the narrower flange or lip.

The strip may have an overall axial dimension or width of at least 40 mm, more preferably at least 50 mm, even more preferably at least 55 mm, e.g. 59.2 mm.

One or both of the flanges or lips may taper in an axial or transverse direction towards its circumferentially or part-circumferentially extending edge, thus being of varying thickness. In one embodiment of the invention, both flanges or lips taper towards their respective circumferentially or part-circumferentially extending edges, a radially outer surface of the strip being linear or flat in transverse section and a radially inner surface of the strip defining an inflection point in transverse section so that the flange or lip is chamfered.

The chamfer of the broader flange or lip may extend over up to about 50 %, preferably up to about 60 %, more preferably up to about 65 %, e.g. about 66.5 % of the axial dimension or width of the broader flange or rib. The invention will now be described, by way of example only, with reference to the accompanying diagrammatic drawings, in which

Figure 1 is a schematic three-dimensional view of a run-flat device in accordance with the invention; Figure 2 is a schematic transverse section of the run-flat device of Figure 1 ;

Figure 3 is a schematic axial section of the run-flat device of Figure 1 fitted on a vehicle wheel;

Figure 4 is a schematic axial section of the run-flat device of Figure 1 fitted on a different wheel; and Figure 5 is a schematic axial section of the run-flat device of Figure 1 fitted to yet another wheel.

In the drawings, reference numeral 10 generally indicates a run-flat device in accordance with the invention. The device 10 includes an annular band body or obstruction body 12 which comprises a pair of part annular strips 14. Integral with each strip 14 is a spacer in the form of a pair of part-circumferentially extending ribs or legs 16, the ribs 16 being parallel and being axially spaced by a distance of about 15.5 mm. The strips 14 and ribs 16 are of metal, in this case being of mild steel. The ribs 16 project radially inwardly from the strips 14, with the strips 14 having a flat (in transverse section) radially outer surface 18. Each strip 14 together with its associated ribs 16 forms part of a part-annular band element 12.1 , 12.2.

The strips 14 each have a radially extending thickness dimension which is small in comparison to an axially extending width dimension, the strips 14 thus having a more or less elongated rectangular transversely cross-sectional profile, with the lengthwise direction of the cross-sectional profile being aligned with a polar axis 20 of the run-flat device 10. The radially outwardly directed part-cylindrical surface 18 of the strips 14 is thus rectilinear in cross-section, being curved about the polar axis 20 only, and therefore not having a compound curvature. In other embodiments of the invention, the strips 14 may, however, each have a convexly curved radially outer surface 18, in cross-section.

The ribs 16 lie in substantially parallel planes which are normal to the polar axis 20, and which are axially spaced, so that the band body 12 has a transverse section as shown in Figure 2. The transverse gap between the ribs 16 is substantially unobstructed, so that there are no reinforcing formations located between the ribs 16.

The band elements 12.1 , 12.2 are connected together at their adjacent and abutting ends by screw-threaded fasteners 22 which are respectively received in pairs of pivot members 24. Each pivot member 24 is pin-shaped and is mounted adjacent a respective end of the associated band element 12.1 , 12.2 for pivoting about an axis which is substantially parallel to the polar axis 20. Each pivot member 24 is passed through a registering pair of pivot openings located in the respective ribs 16 and which are axially aligned. Each pivot member 24 has an enlarged head at one end thereof and an opening for receiving a split pin 26 at its other end.

Each pair of pivot members 24 comprises a guide member 28 and a screw- threaded member 30. The fastener 22, which is in the form of a bolt, passes slidably through a transversely extending passage in the guide member 30, a head of the fastener or bolt 22 being located in a sunken socket provided laterally in the guide member 28. A screw-threaded end portion of each fastener or bolt 22 is screwingly received in a screw-threaded passage extending transversely through the respective screw-threaded member 30, to connect the ends of the band elements 12.1 , 12.2 together.

Each band element 12.1 , 12.2 includes a connection opening or window 32 adjacent each of its ends. The device 10 thus has four connection windows 32, each window 32 being provided as a cut-out in the strip 14 for permitting manual access to the respective pivot members 24 and the fasteners or bolts 22.

Each window 32 is elongated in a circumferential direction, having semicircular rounded ends. Furthermore, each window 32 has a width more or less equal to and axially in register with the transverse gap between the ribs 16. Each window 32 is completely enclosed by a material provided by the strip 14, such that a bridge portion defining an end of the respective band elements 12.1 , 12.2 borders each window 32 at an outer end thereof. The bridge portion is provided by the semi-circular cylindrical strip 14 and thus lies at the same diameter from the polar axis 20 than the remainder of the strip 14. As can be clearly seen in Figure 2 of the drawings, the ribs 16 are closer to one edge 34 of the strip 14 than to another, axially spaced edge 36 of the strip 14. The ribs 16 thus divide the strip 14 into a narrow flange or lip 38 and a broad flange or lip 40. In the embodiment of the invention shown in the drawings, the flange 38 has a width of 10.4 mm and the flange 40 has a width of 20 mm, thus being about 1 .92 times the width of the flange 38. The strip 14 has an overall width of 59.2 mm and the ribs 16 have a radially extending dimension of 12.5 mm and a maximum width of about 5.5 mm.

As can also be clearly seen in Figure 2 of the drawings, each flange or lip 38, 40 has a chamfered region 42, 44. The chamfered region 42 has a much smaller axial dimension or width than the chamfered region 44 which, in the embodiment of the invention shown in the drawings, extends up to about 66.5 % of the width of the flange

40.

In use, the band elements 12.1 , 12.2 are disconnected at one of the connections, and the device 10 is fitted on a vehicle wheel, such as the vehicle wheel or rim 46 shown in Figure 3 of the drawings such that the band elements 12.1 , 12.2 are located in a well 48 of the wheel 46, extending circumferentially along it. The ribs 16 thus project radially inwardly and seat on the wheel 46. Once positioned, the disconnected ends are connected together by threading the fastener or bolt 22 through its associated screw-threaded pivot member 24. When thus in position, as shown in Figure 2, the run-flat device 10 provides the wheel 46 with run-flat capability, as a bead 50 of a tyre 52 mounted on the wheel 46 can not enter the wheel well 48, because the wheel well 48 is obstructed by the device 10, thus inhibiting or restricting dismounting of the tyre 52 from the wheel 46.

It will be appreciated that the bead 50 of the vehicle tyre 52 has a diameter smaller than that of a rim flange 54 of the wheel 46, the bead 50 being non-extensible. The wheel well 48 is thus provided to permit fitment of the tyre 52 by inserting part of the bead 50 in the wheel well 48, enabling a diametrically opposite part of the bead 50 to pass over the rim flange 54. However, when the run flat device 10 is inserted in the wheel well 48, the opposite operation is not permitted, thus restricting dismounting of a flat pneumatic tyre 52. The wheel well 48 of the wheel 46 shown in Figure 3 comfortably receives the run-flat device 10 such that the strips 14 effectively bridge the wheel well 48. The run-flat device 10 is thus dimensioned to be particularly suitable to a wheel well 48 as shown in Figure 3. As will be appreciated, for the wheel well 48 shown in Figure 3, it is not important whether or not the ribs 16 are located in a central region of the strip 14 or closer to one edge 36, as is in fact the case for the run-flat device 10.

In Figure 4, another wheel 56 with a much wider wheel well 58 is shown. The wheel well 58 is defined by a frusto-conical portion of the wheel 56. The run-flat device 10 is mounted as close as possible to one side of the wheel well 58 and in fact one of the ribs 16 is riding slightly up onto one side of the wheel well 58 so that the strip 14 is angled slightly downwardly towards the frusto-conical surface of the wheel well 58. As a result of the additional width provided by the broad flange or lip 40, the strip 14 extends across a substantial portion of the wheel well 58. Where the edge 36 of the strip 14 is located, the diameter of the wheel well 58 is sufficiently large to prevent or inhibit dismounting of the tyre 50 from the wheel 56. For the wheel 56, it is thus advantageous that the ribs 16 are located closer to the edge 34 than to the edge 36 and it is also advantageous that the strip 14 has a width which is substantially greater than those of conventional run-flat devices of which the applicant is aware.

In Figure 5, a wheel 60 with a narrow wheel well 62 is shown. As a result of the off-centre location of the ribs 16 and the large chamfer 44, the run-flat device 10 is also capable of being fitted into the wheel well 62, as shown in Figure 5.

Advantageously, the run-flat device of the invention, as illustrated, is capable of being fitted to a variety of different vehicle wheels or rims and is not restricted to a vehicle wheel or rim provided by a single manufacturer.

Claims

CLAIMS:

1 . A run-flat device for a vehicle wheel, the run-flat device including an annular band body or obstruction body which can be fitted to a vehicle wheel to obstruct a circumferentially extending well of the vehicle wheel, the band body including at least one at least part-annular strip and a radially inwardly projecting spacer fast with the strip for engaging a vehicle wheel to space the strip from the wheel, the spacer being located closer to one circumferentially or part-circumferentially extending edge of the strip than to another axially or transversely spaced circumferentially or part-circumferentially extending edge of the strip.

2. The run-flat device as claimed in claim 1 , in which the spacer includes a pair of circumferentially or part-circumferentially extending ribs or legs which are integral with the strip, the ribs being more or less parallel and being axially or transversely spaced.

3. The run-flat device as claimed in claim 1 or claim 2, in which the band body includes a pair of the part-annular strips which, when fitted together end to end, define an annular body.

4. The run-flat device as claimed in any one of the preceding claims, in which the spacer divides the strip into two flanges or lips of which a broader one thus has a longer axial dimension or width than the other, narrower flange or lip, the flanges or lips being of substantially constant width, and the axial dimension or width of the broader flange or lip being at least about 1 .5 times the axial dimension or width of the narrower flange or lip.

5. The run-flat device as claimed in claim 4, in which the axial dimension or width of the broader flange or lip is at least about 1 .75 times the axial dimension or width of the narrower flange or lip.

6. The run-flat device as claimed in claim 4 or claim 5, in which one or both of the flanges or lips taper in an axial or transverse direction towards its circumferentially or part-circumferentially extending edge, thus being of varying thickness.

7. The run-flat device as claimed in any one of claims 4 to 6 inclusive, in which both flanges or lips taper towards their respective circumferentially or part- circumferentially extending edges, a radially outer surface of the strip being linear or flat in transverse section and a radially inner surface of the strip defining an inflection point in transverse section so that the flange or lip is chamfered.

8. The run-flat device as claimed in claim 7, in which the chamfer of the broader flange or lip extends over up to about 50 % of the axial dimension or width of the broader flange or rib.