BACKGROUND [0002] Tire assemblies that allow for continued operation of a vehicle at zero or low inflation pressure have been previously described. For example, a run-flat assembly is illustrated in U. S. Patent No. 5,891, 279 (Lacour), which is owned by the assignee of the present invention and is incorporated by reference herein in its entirety for all purposes. Tire assemblies of this type have a ring-shaped component disposed on the rim of the wheel. The tire surrounds this support ring. When the tire loses a certain amount of air pressure, the tire will deform and contact the support ring. The load of the vehicle and the dynamic load of the ride will then be at least partially borne by the support ring.

[0003] A perspective view of an exemplary wheel 12 as may be used with a run-flat tire assembly is shown in Figs. 1 and 2. During operation, a series of stress fractures or cracks 70 may develop on rim 16 of wheel 12 due to stress concentrations. While cracks 70 can occur in other locations, Figs. 1 and 2 depict cracks 70 along an outboard bead seat hump 38 of an inboard bead seat 32.

[0004] The present invention provides an improvement upon wheels used in run-flat tire assemblies by providing for a wheel having one or more strength increasing features, referred to herein as ribs, located on the inner surface of the rim for increasing the strength of the wheel. Although such improved rim will be described with regard to run-flat assemblies, the present invention may also be used with rims in other than run-flat assemblies.

SUMMARY [0005] Various features and advantages of the invention will be set forth in part in the following description, or may be obvious from the description. The present invention provides a wheel that includes a rim having one or more strength increasing features, such as ribs, located along the inner surface of the rim. The invention can be used with both run-flat tire assemblies and other tire assemblies.

[0006] In one exemplary embodiment, the present invention provides a wheel for use on a vehicle that includes a wheel disk configured for attachment to the vehicle and a rim that is attached to the wheel disk. The rim is configured such that a tire may be mounted onto the rim. The rim includes an outer surface and an inner surface and has an inboard bead seat and an outboard bead seat located upon on the outer surface of the rim. At least one rib is located on the inner surface of the rim at a position that is radially inward from the inboard bead seat.

[0007] In another exemplary embodiment, a wheel for use on a vehicle is provided that includes a wheel disk that is configured for attachment to a wheel hub of the vehicle. The wheel disk has an axis extending in an inboard direction and an outboard direction and about which the wheel rotates during operation. A rim is formed integrally with the wheel disk and has an outer surface and an inner surface. The outer surface of the rim is configured such that a tire may be mounted onto the outer surface. The rim is coaxial with the axis of the wheel disk and has an outer circumference and an inner circumference. At least one rib is integrally formed with the rim such that the rib extends from the inner surface of the rim towards the axis of the wheel disk. The rib is configured to increase the moment of inertia of the rim and strengthen the rim. The rib is a continuous feature around the entire inner circumference of the rim. The position of the rib may be determined solely by locating the rib where it counteracts a stress concentration occurring in the outer surface of the rim during operation of the wheel.

Alternatively, the rib may be positioned to take in consideration other design concerns (e. g. clearance) while also counteracting a stress concentration.

[0008] The wheel may be configured such that the outer surface of the rim has an inboard bead seat with an inboard bead seat hump and an outboard bead seat hump, and such that the outer surface of the rim has an outboard bead seat with an inboard bead seat hump and an outboard bead seat hump. Here, the outboard bead seat is located closer to the wheel disk than the inboard bead seat. The outer surface of the rim has a support ring seat located intermediate the inboard bead seat and the outboard bead seat for run-flat operation. At least one rib may be located radially inward from the inboard bead seat hump of the inboard bead seat.

Alternatively, at least one rib may be located radially inward from the outboard bead seat hump of the inboard bead seat. In certain embodiments, at least one rib may include a plurality of openings that extend through the width of the rib and are configured for allowing the passage of water or other materials therethrough.

[0009] In still another exemplary embodiment of the present invention, a rim for use on a wheel of a vehicle is provided. The rim has an axis about which rotation occurs during operation of the vehicle. The rim includes an outer surface and an inner surface. The outer surface is configured such that a tire may be mounted onto the rim. A plurality of ribs are located on the inner surface of the rim. Each of the plurality of ribs extends from the inner surface of the rim towards the axis. At least one of the plurality of ribs is positioned at a location that reduces stress concentration in the outer surface of the rim during vehicle operation.

[0010] These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS [0011] A full and enabling disclosure of the present subject matter, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which: [0012] Figure 1 is a perspective view of a wheel as may be used in a run-flat tire assembly.

[0013] Figure 2 is a partial cross-sectional view of the wheel of Figure 1.

[0014] Figure 3 is a partial cross-sectional view of a wheel used in a run-flat tire assembly in accordance with one exemplary embodiment of the present invention that has a plurality of ribs located on the inner surface of the rim.

[0015] Figure 4 is a partial cross-sectional view of a run-flat tire assembly used in accordance with one exemplary embodiment of the present invention. The rim of the wheel has a single rib located at the most inboard portion of the inner surface of the rim.

[0016] Figure 5 is a partial cross-sectional view of a wheel used in a run-flat tire assembly in accordance with one exemplary embodiment of the present invention. A plurality of ribs are located on the inner surface of the rim, and each of the ribs has a plurality of openings disposed therethrough.

[0017] Figure 6 is a partial side view of the wheel of Figure 5.

[0018] Figure 7 is a partial cross-sectional view of a conventional tire assembly used in accordance with one exemplary embodiment of the present invention. The rim of the wheel has a plurality of ribs disposed on the inner surface of the rim.

[0019] Figure 8 is a partial side view of the conventional tire assembly of Figure 7.

[0020] Figure 9 is an exploded assembly view of a tire assembly used in accordance with one exemplary embodiment of the present invention. The tire assembly is configured for being attached to a wheel hub of a vehicle.

[0021] Repeat use of reference characters throughout the present specification and appended drawings is intended to represent same or analogous features or elements of the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS [0022] Reference will now be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, and not meant as a limitation of the invention. For example, features illustrated or described as part of one embodiment can be used with another embodiment to yield still a third embodiment. It is intended that the present invention include these and other modifications and variations.

[0023] Fig. 3 shows an exemplary embodiment of the present invention in which rim 16 is provided with a plurality of ribs 21 located on and extending from an inner surface 22 of rim 16. As shown in Fig. 3, four ribs are present including first rib 24, second rib 26, third rib 28, and fourth rib 30. However, it is to be understood that in other exemplary embodiments of the present invention, any number of ribs 24 may be employed. For instance, a single rib may be employed, or six ribs may be employed in accordance with various exemplary embodiments.

[0024] The addition of ribs 21 increases the mass of rim 16, which in turn strengthens rim 16, increases its moment of inertia, and makes it less susceptible to cracks 70. A single rib or any number of ribs 21 may be located on inner surface 22 at positions selected to counteract stress concentrations located on outer surface 20 of rim 16. One of ordinary skill in the art will understand how various techniques, including finite element analysis, may be used to determine the location of stress concentrations in rim 16. Once the location of one or more stress concentrations is determined, a single rib (such as rib 24) or a plurality of ribs 21 may be positioned to strengthen rim 16 and help prevent cracks 70.

[0025] The position of a rib along inner surface 22 may be determined solely with regard to the most effective position for counteracting a stress concentration. For example, once the location of a stress concentration is determined, the position of rib 24 along inner surface 22 may be decided solely with regard to counteracting such stress concentration. Alternatively, a rib may be positioned in a manner that balances the objective of counteracting a particular stress concentration in rim 16 with other considerations such as spatial factors. By way of example, rib 24 might be located at a position that counteracts a stress concentration but also allows for rim 16 to clear the components of a braking system or suspension during installation of wheel 12 onto a wheel hub 62 (as shown in Fig. 9).

[0026] Continuing with the description of the exemplary embodiment of Fig. 3, ribs 21 extend from inner surface 22 of rim 16 towards axis 64, which has an inboard direction 66 and an outboard direction 68. Ribs 21 may extend around the entire circumference of inner surface 22 of rim 16 such that ribs 21 completely surround axis 64. Alternatively, ribs 21 may extend around only a portion of the circumference of inner surface 22 of rim 16. When employing a plurality of ribs 21, one or more ribs may be continuous around the entire circumference of inner surface 22 of rim 16, while other ribs 24 are discontinuous at one or more locations.

[0027] As can be seen in Fig. 3, rib 24 is located at the most inboard portion of rim 16. More specifically, rib 24 is located radially inward from inboard bead seat hump 36 of inboard bead seat 32. For embodiments of the present invention where only a single rib is used, the positioning of rib 24 as shown in Fig. 3 has been found to be most beneficial for counteracting what has been determined to be a high concentration of stress in outboard bead seat hump 38 of inboard bead seat 32.

[0028] As shown with the embodiment of Fig. 3, second rib 26 is located radially inward from outboard bead seat hump 38 of inboard bead seat 32. Additionally, third and fourth ribs 28 and 30 are located in the outboard direction 68 from inboard bead seat 32. Fourth rib 30 is located radially inward from support ring seat 44, while third rib 28 is located radially inward from a portion of rim 16 that is between inboard bead seat 32 and support ring seat 44. The present invention includes various exemplary embodiments in which one or more of the plurality of ribs 21 may be located at various points along inner surface 22 of rim 16. For instance, in accordance with one exemplary embodiment of the present invention, third rib 28 may also be located radially inward from support ring seat 44. By way of further example, rib 24 may be located radially inward from one or both of the inboard and outboard bead seat humps 40, 42 of outboard bead seat 34. Using the teaching disclosed herein, one of ordinary skill in the art will understand that the present invention is not limited to the number and locations of ribs 21 shown in the drawings, but includes various exemplary embodiments in which ribs 21 may be formed in any number and located at any point on inner surface 22 of rim 16 in order to counteract stress concentrations.

[0029] As shown in Fig. 3, rib 24 has a generally rectangular cross-section with a rounded tip 54. Additionally, second, third, and fourth ribs 26,28, 30 are also each made with a generally rectangular cross-section, each of the ribs having a corresponding rounded tip 56,58, and 60 associated therewith. Rounded tips 54,56, 58, and 60 are provided in order to reduce stress concentrations. This reduction in stress can in turn allow for less mass to be used in ribs 21.

However, ribs 21 may be formed in a variety of cross-sectional shapes. By way of example, ribs 21 may be square shaped, semi-circular shaped, or triangular. Fig. 4 shows an exemplary embodiment of the present invention in which a single rib 24 is located opposite from inboard bead seat hump 36 of inboard bead seat 32, and is generally square-shaped without having any rounded portions formed therein.

[0030] Fig. 5 shows an exemplary embodiment of the present invention in which ribs 21 are provided with one or more openings 46 to allow for water, ice, snow, mud, or other materials to be removed from inner surface 22 of rim 16 and transported out of wheel 12. As can be seen in Fig. 5, an opening 46 spans across the entire width of rib 24. Similarly, openings 48, 50, and 52 are present in the second, third, and fourth ribs 26,28, and 30 respectively.

Openings 46,48, 50, and 52 may be positioned such that they are all placed at the same axial distance from axis 64. Alternatively, one or more of openings 46,48, 50, and 52 may be placed at various distances from axis 64 such that openings 46,48, 50, and 52 are all not aligned with one another. Although shown as extending in the axial direction, openings 46, 48, 50, and 52 may have a radial component or circumferential component in accordance with other exemplary embodiments of the present invention such that openings 46,48, 50, and 52 are angled or slanted.

[0031] Fig. 6 shows a partial side view of the exemplary embodiment of Fig. 5 in which openings 46 are shown as being a plurality of holes. In accordance with other exemplary embodiments of the present invention, instead of being circular, openings 46 may be square- shaped, rectangular-shaped, oval-shaped, or may have any cross-sectional shape as is known in the art. Additionally, openings 46 need not have the same cross-sectional shape from one side of rib 24 to the other, but may have one or more different cross-sectional shapes from one side to the other. Any number of openings 46 may be formed in rib 24, and may be located at any circumferential location along rib 24. As also shown in Fig. 6, openings 48 formed in second rib 26 are smaller than openings 46 formed in rib 24, and openings 48 are aligned with openings 46. Alternatively, openings 48 may be staggered from openings 46 such that they would not be visible in a view such as the side view shown in Fig. 6. One of ordinary skill in the art, using the teachings disclosed herein, will appreciate that various configurations of the openings in the rib or ribs of a particular embodiment of the present invention can be used to allow water and other materials to be evacuated from the rim 16.

[0032] Although described as being used in conjunction with a run-flat tire assembly 10, the present invention may be used with assemblies other than run-flat tire assemblies 10. Fig. 7 shows an exemplary embodiment of the present invention in which a non run-flat tire assembly 10 is shown in partial cross-section. Beads 86,88 are located in an inboard bead seat 32 and in an outboard bead seat 34. Wheel 12 may be strengthened by the inclusion of one or more ribs 24 located on inner surface 22 of rim 16. As shown in Fig. 7, a rib 24 and a second rib 26 are located on inner surface 22. Ribs 24,26 may be provided in any number or any configuration as discussed above with respect to other exemplary embodiments of the present invention. Fig.

8 shows a side view of the exemplary embodiment in Fig. 7 where a plurality of openings 46, 48 may be seen as being located in ribs 24,26 to aid in the evacuation of water, ice, snow, mud, or the like. As can be seen, ribs 24 used in accordance with the present invention may be provided on any type of wheel 12, used in any type of tire assembly 10.

[0033] A tire assembly 10 is shown in Fig. 9. Here, wheel 12 defines a cavity (not shown) in its interior into which wheel hub 62 of a vehicle may be located. Wheel hub 62 is provided with one or more bolts 90 that are inserted into holes 92 formed in wheel disk 14 of wheel 12.

Wheel hub 62 may then be securely fastened to tire assembly 10 through the use of lug nuts or other fasteners.

[0034] It should be understood that the present invention includes various modifications that can be made to the exemplary embodiments of tire assembly 10 and wheel 12 as described herein that come within the scope of the appended claims and their equivalents.