CERAMIC BALANCE WEIGHT

Abstract

This wheel weight is a body consisting of ceramic. The wheel weight is fastened to a rim with material fit and/or positive fit. The body of the wheel weight has a cross section that decreases along a prescribed direction, such as the directed normal to the upper surface of the body. The body can have a high specific weight of two or more g/cm.sup.3 for example.

Claims

1. Wheel weight (5) for installation on a motor vehicle wheel for balancing the wheel; wherein the wheel weight (5) is a rigid body (7); wherein the rigid body (7) is a ceramic; wherein the ceramic is an aluminum-oxide ceramic that is highly compressed and sintered; and at least one fastening means for attaching the wheel weight (5) to the motor vehicle wheel.

2. Wheel weight according to claim 1, wherein a surface (8) that faces the wheel in the fastened state has an arch.

3. Wheel weight according to claim 1, wherein the fastening means is a layer of adhesive material that is arranged on a surface (8) of the body (7).

4. Wheel weight according to claim 1, wherein the fastening means comprises a clamp (15).

5. Wheel weight according to claim 4, wherein an indentation (21) or a projection (14) is configured on one surface of the body (7) to form a positive-locking connection with the clamp (15).

6. Wheel weight according to claim 5, wherein the indentation (21) or the projection (14) has a noncircular cross section.

7. Wheel weight according to claim 1, wherein the body (7) is configured undercut-free and has a cross section that increases from one surface (9) to an opposite surface (8).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] FIG. 1 is a motor vehicle wheel with wheel weights mounted thereon.

[0024] FIG. 2 is a wheel weight in a separate enlarged and perspective representation.

[0025] FIG. 2a is a top view showing a plurality of wheel weights arranged in a series with one another.

[0026] FIG. 3 is a wheel weight in side view.

[0027] FIG. 4 is a modified embodiment of a wheel weight in side view.

[0028] FIG. 5 is a first embodiment of a wheel weight with a fastening shackle in perspective exploded view; and

[0029] FIG. 6 is another embodiment of a wheel weight according to the invention with a fastening shackle in exploded view. FIG. 6 also show clip 16(a).

[0030] FIG. 3a shows surface 9 configured as an arched concave surface 9a. FIG. 3a also shows wheel weight 5a.

[0031] FIG. 3b shows surface 9 configured as a convex surface 9b. FIG. 3b also shows wheel weight 5b.

[0032] FIG. 7 shows wheel weight 5c in the shape of a frustum of a pyramid.

[0033] FIG. 8 shows wheel weight 5d in the shape of a frustum of a cone.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

[0034] FIG. 1 illustrates a motor vehicle wheel 1, which comprises a tire 2 and a rim 3 preferably consisting of metal.

[0035] The rim 3 has an inner circumferential surface 4, cylindrical for example, to which the one or more wheel weights 5, 6 are arranged. These serve to balance the motor vehicle wheel 1. They have identical or different shapes and weights. The wheel weight 5 will now be described in more detail below on behalf of both wheel weights 5, 6. This description accordingly applies to wheel weight 6, although it can differ in shape and size.

[0036] FIG. 2 illustrates the wheel weight 5 in perspective view, as evident it features an essentially rectangular body 7, which can be surrounded by six plane surfaces. But preferably at least one of the six surfaces is configured arched. In FIG. 2, this is the bottom surface 8, which in its installed state fits the inner circumferential surface of the rim 3. This surface 8 can be provided with an arch that coincides at least approximately with the arch of the inner circumferential surface 4. In this connection, a precise mathematical congruence does not matter. A slightly convex arching of the surface 8 is nevertheless viewed as advantageous in order to achieve an at least approximately extensive contact between the surface 8 and the inner circumferential surface 4. FIG. 2 also shows adhesive material 22 on surface 8.

[0037] For further explanation, we refer to FIG. 3, which likewise depicts the wheel weight 5. The surface 8 opposite the surface 9 can be configured as a plane surface. It can also be shaped otherwise and be arched concave or convex for example. It moreover can be provided with elevated or indented reliefs, inscriptions, logos and the like. FIG. 2 shows logo 23 on the surface 9.

[0038] The lateral surfaces 10, 11, 12 of the wheel weight 5 are preferably plane surfaces. The lateral surfaces 10, 11, 12 can transition into one another at straight or rounded edges. The lateral surfaces 10, 11, 12 are preferably arranged somewhat inclined against the surface 8 and/or the upper surfaces 9. The inclination angle can be, for example, one or a few degrees. In FIG. 2 it is depicted as superelevated. Because of the stated inclination, the cross-sectional area of the wheel weight 5 continuously decreases from a surface 8 to the upper surface 9. The wheel weight 5 is thus preferably a frustum of a pyramid with rectangular or quadratic base or a frustum of a cone with circular or elliptical base.

[0039] The upper surface 9 is preferably configured rectangular or quadratic. But it can also be configured circular, oval, hexagonal, pentagonal or otherwise. In particular, it is possible to provide arrow-shaped base and upper surfaces, FIG. 2a illustrates in top view a plurality of identically or differently sized wheel weights arranged in series with one another. The corresponding upper surfaces are labeled 9a, 9b, 9c. The single wheel weights can very easily be lined up in a row, facilitating the alignment inside the row.

[0040] The upper surfaces 9 can be configured planar or, as shown in FIG. 4, concavely or convexly arched in one or more directions. FIGS. 3a and 3b show the surface 9 can also be shaped otherwise and be arched concave 9a or convex 9b for example. See FIG. 3a and FIG. 3b.

[0041] The body 7 of wheel weight 5 described above and below consist of ceramics, preferably a sintered ceramic. In principal, any suitable ceramic can be used. Preferably, the ceramic is an aluminum-oxide ceramic. This can also contain other metal oxides such as zirconium oxide for example. For production, a blank is produced out of a suitable base material of powdered nature or at least of powdered ingredients in the pressing process and then fired. The blank is preferably highly compressed so that the body 7 of the wheel weight 5 has a small volume with high weight.

[0042] To increase the weight, heavy ingredients, for example in the form of one or more compact ingredients or materials of high density existing as granular or powdered ingredients, can be worked into the body 7. The ceramic material of the body 7, for example, can contain barium compounds such as barium oxide, or barium sulfate (barite). The ceramic 7 preferably does not contain any ingredients that are hazardous to health or the environment such as heavy metals.

[0043] Unlike lead weights, the wheel weights 5, 6 consisting of ceramics are rigid and their geometric shape is precisely determined. During their production, they can be calibrated in regard to weight, e.g. before or after sintering. This can be accomplished by weighing and subsequent stripping, e.g. scraping, boring, milling, grinding or the like. This applies to all of the embodiments presented here, including the embodiment according to FIG. 4, which depicts an approximately lenticular wheel weight 5 having a spherical upper surface 9 and round (approximately cylindrical, conical to be exact) lateral surface 13 extending all around.

[0044] The wheel weights 5, 6 can be fastened to the inner circumferential surface 4 by gluing. Adhesive material can serve this purpose. It is also possible to use a double-sided adhesive tape for this or similar means that connect the surface 8 to the inner circumferential surface 4. Moreover, it is possible to fasten the wheel weights consisting of ceramics to the rim 3 with a positive fit. FIG. 5 depicts an example. The wheel weight 5a depicted there largely corresponds to the wheel weight 5 according to FIG. 2 described above. Its surface 8 can be arched or, as illustrated, also be configured planar. A positive-locking means, e.g. in the form of a projection 14, can be arranged on the upper surface 9. These means can, as illustrated, be configured approximately rectangular, preferably shaped like the frustum of a pyramid to be precise. FIG. 7 shows the wheel weight 5 in the shape of a frustum of a pyramid. FIG. 8 shows the wheel weight 5 in the shape of a frustum of a cone. Like the lateral surfaces 11, 12 of the body 7, the lateral surfaces of the projection 14 can also be inclined slightly inwards. The front end of the projection 14 is again preferably planar or also rounded, e.g. configured curved spherically convex or the like.

[0045] The associated fastening shackle 15 consists of steel, for example. It has a clip 16, which can have an indentation or a window 17 to receive the projection 14. The contour of the window 17 preferably corresponds to the external contour of the projection 14, so that the latter locates into the window 17 with play or also with light clamping action. In the green state, the projection can have a length that is larger than the thickness of the clip 16. If the mass of the wheel weight is to be calibrated, it is possible to strip, e.g. grind off, the front of the projection somewhat before or after the firing of the body 7. Alternatively, the body 7 can be stripped at other locations before or after firing to adjust the desired mass.

[0046] The fastening shackle 15 can have a bent end 18 that serves for fastening to the rim 3.

[0047] A compensation body 19 is preferably fastened to the surface 8. The compensation body 19 preferably coincides with the external contour of the body 7. It preferably has a certain flexibility to fit the inner circumferential surface 4 and compensate for any differences in curvature of the surface 8 and inner circumferential surface 4. The compensation body 19 can consist, for example, of non-vulcanized or slightly vulcanized rubber, felt, acryl, microcellular rubber or other plastically or elastically flexible materials. Compensation body 19 can cover the surface 8 completely or partially and be configured strip-shaped or annular, for example. See FIG. 7 which shows strip-shaped compensation body 19a. It provides for a rattle-free fit of the body 7 on the rim 3; E.g. the compensation body 19 can be bonded to the surface 8. The compensation body 19 can also be vulcanized onto the surface 8. The compensation body 19 can be provided with adhesive material 22 or sticking agent on its side facing the wheel. FIG. 9 shows adhesive material 22 in a striped configuration on surface 8. Alternatively, the surface facing the wheel can be free of adhesive means or sticking agents.

[0048] The above description of different embodiments of the wheel weight 5, especially the description of the embodiment according to FIG. 5, correspondingly applies to the wheel weight 5b according to FIG. 6. Further, we point out that the positive fit between the fastening shackle 15 and the wheel weight 5b is formed by a projection 20 of the clip 16 and a corresponding indentation or recess 21 in the wheel weight 5b. The projection 20 can be formed by a bent end of the clip. The indentation 21 can be hole-like or channel-like indentation which is arranged, for example, in the center of the upper surface 9 or also eccentrically within it. An optional compensation body 19 again serves for fitting and improved contact of the wheel weight 5b on the rim 3.

[0049] The wheel weight 5 according to the invention consists of a body 7 consisting of ceramics. It is provided with a means for fastening to a rim 3 with a material fit and/or positive fit. The body 7 has a cross section that decreases along a prescribed direction, such as the direction normal to its upper surface 9. The ceramic body can have a high specific weight of two or more g/cm.sup.3 for example.

[0050] The above detailed description of the present invention is given for explanatory purposes. It will be apparent to those skilled in the art that numerous changes and modifications can be made without departing from the scope of the invention. Accordingly, the whole of the foregoing description is to be construed in an illustrative and not a limitative sense, the scope of the invention being defined solely by the appended claims.

REFERENCE CHARACTERS

[0051] 1 Motor vehicle wheel [0052] 2 Tire [0053] 3 Rim [0054] 4 Inner circumferential surface [0055] 5 Wheel weight 5, 5a and 5b [0056] 6 Wheel weight [0057] 7 Ceramic Body [0058] 8 Lower Surface [0059] 9 Upper surface (also 9a, 9b, 9c) [0060] 10 Lateral surface [0061] 11 Lateral surface [0062] 12 Lateral surface [0063] 13 Lateral surface [0064] 14 Projection [0065] 15 Fastening shackle [0066] 16 Clip [0067] 17 Window [0068] 18 End [0069] 19 Compensation body [0070] 20 Projection [0071] 21 Indentation or recess [0072] 22 Adhesive material [0073] 23 Relief, inscriptions or logos