Field of the invention

The invention relates to a self-adhesive balancing weight, which may be attached to the rim of a wheel of a vehicle for balancing the wheel.

Description of the related art

The contact surface of self-adhesive balancing weights generally is formed so as to accurately fit to the counter surface of the wheel rim holding the weight to provide as much contact surface and thereby adhesive surface area as possible in order to ensure safe fixation. As the rim profiles of different types of wheels - coming from different wheel manufactures for instance - differ in a wide range, a great number of different balancing weights has to be kept on stock.

Particularly, the counter-surface of aluminum wheel rims, to which the balancing weights have to be fixed, often are concave-convex shaped so that accurate adaptation of balancing weights is difficult.

WO 99/00609 discloses self-adhesive balancing weights the contact surfaces of which are exactly complementary to the shape of the counter-surface of the respective wheel rim so that they could not be used with wheel rims of different shape. There is a large number of different rim geometries in the market. Furthermore, there are significant mechanical tolerances in the rims which may be in an order of 1 mm.

For reliably attaching balancing weights to a rim, there are two basic concepts. Self-adhesive balancing weights usually have a planar back surface which is de- signed to adhere to an at least essentially planar surface which is curved only around the rotational axis of the wheel. Accordingly, the self-adhesive balancing weights have to be bent only in one axis. The second type of balancing weights are clip-on balancing weights which are held to the rim by a spring clip. These balancing weights usually are held in an outer groove of the rim and therefore must at least roughly be adapted to the contour of the groove. Due to the large number of different grooves, at least a significant number of differently formed balancing weights is required.

Summary of the invention The object of the present invention is to provide self-adhesive balancing weights which fit to several different rim shapes.

The solution of the above-mentioned problem is described in the independent claim 1, whereas further embodiments and improvements are described in the claims dependent on claim 1. For finding a solution of the problem, a large number of rims has been analyzed and checked for possible locations for mounting of balancing weights. A balancing weight which fits to most rims on the market, provides the following features.

A balancing weight according to the present invention comprises a body having at least two weight sections being pivotably connected with each other by means of a connecting element, which may be like a hinge, and preferably having a pivot axis tangential with respect to the axis of a wheel rim carrying the balancing weight.

In another embodiment, a belt or chain of balancing weights are held on a carrier like a plastic belt and most preferably on a self-adhesive tape. The carrier defines a longitudinal axis which may be at the center of a first plane of a planar tape. The longitudinal axis preferably is a line along the center in the plane of the carrier. The balancing weights comprise a body having at least two weight sections being pivotably connected with each other by means of a connecting element having a pivot axis parallel to said longitudinal axis.

By pivoting the weight sections one with respect to the other, the balancing weight may at least to a certain extent be adapted to different concave or even convex shapes of wheel rims, even when its contacting surface is not accurately adapted to the respective counter-surface, whereby at least a number of contacting lines corresponding to the number of weight sections will be established.

According to a preferred embodiment of the invention, the hinge like connecting element is formed as a hinge integral with the adjacent weight sections assuming that the material of the balancing weight on the one hand and the thickness of the hinge allows for bending.

According to another embodiment of the present invention, the hinge like connecting element consists of a flexible tape to which the weight sections are fixed. In this case the weight sections may be made of a material whatever, for instance a material which is not flexible or ductile. Preferably the flexible tape is an adhesive tape with double-side adhesion layers which, at the same time, serves to fix the balancing weight to the wheel rim.

In a further embodiment, two balancing weight sections are only connected by the self-adhesive tape. Preferably, at least one of the balancing weight sections has a chamfered or rounded edge for sliding or pivoting against the other balancing weight section. It is further preferred that a spacing gap is formed between the respective weight sections. The form and dimension of the gap determines the possible pivot angle between the weight sections.

In order to achieve a better adaptation of the balancing weight to the wheel rim preferably the contact surface of at least one of the weight sections is at least approximately complementary to respective counter-surfaces of the wheel rim. In this way a larger contact area and therewith effective adhesive area may be achieved.

Description of Drawings

In the following, the invention will be described by way of example, without limitation of the generally inventive concept, by examples of embodiments with reference to the drawings.

In the drawings,

Figure 1 is a radial partial sectional view of a steel wheel rim with a self-adhesive balancing weight arranged in a rim horn;

Figure 2 is a radial partial sectional view of an aluminum wheel rim with a self- adhesive balancing weight mounted at the rim horn;

Figure 3 is a perspective partial view of an aluminum wheel rim similar to figure 2 with a self-adhesive balancing weight and a conventional clip-on-balancing weight, both mounted on the rim horn.

Figure 4 is a radial partial sectional view of a steel wheel rim with a self-adhesive balancing weight arranged in a rim horn with a smaller radius;

Figure 5 is a radial partial sectional view of a steel wheel rim with a self-adhesive balancing weight arranged in a rim horn with a larger radius;

Figure 6 is a radial partial sectional view of a steel wheel rim with a chain of self- adhesive balancing weights arranged in a rim horn;

Figure 7 is a balancing weight with extensions for simplified handling.

Figure 8 shows a balancing weight with a smaller section and a larger section, which can be adapted to a rim with a comparatively small curve radius. Figure 9 shows an adhesive tape for a plurality of balancing weights. Figure 10 shows a more flexible adhesive tape. Figure 11 shows a further embodiment. Figure 12 shows another embodiment in detail. Figure 13 shows another embodiment in detail.

The wheel rim 2 shown in figure 1 consists of a wheel disk 4 and a wheel band 6 ending in a wheel horn 8 as generally known in the art. A tire 10 is mounted to the wheel rim 2. A self-adhesive balancing weight 12 is arranged in the rim horn 8, the balancing weight consisting of two weight sections 12a and 12b. The weight sections 12a, 12b are pivotably connected with each other by means of a hinge-like connecting element 14 having a pivot axis tangential with respect to the axis of a wheel rim (not shown) carrying the balancing weight. The connecting element 14 allows the weight sections to swivel one with respect to the other to a certain extent. In this manner the balancing weight may be adapted to differently formed rim horns so as to assure a contact area as large as possible. The contact surfaces of the weight sections 12a, 12b contacting the rim horn 8 are fixed to the inner surface of the rim horn 8 by means of a double-side adhesive tape (12c, 12d). A gap 15 is formed between the weight sections 12a, 12b, the dimension and form of which determines the possible swivel angle between the weight sections. In the embodiment shown in figure 1 the hinge-like connecting element 14 is formed as an integral hinge, i.e. integral with the respective adjacent weight sections 12a, 12b. That means that the balancing weight 12 must consist of a material having a certain flexibility. Figure 2 shows an aluminum wheel rim 16 also ending in a rim horn 18. A tire 20 is mounted on the wheel rim 16.

A two-piece-balancing weight 22 of the self-adhesive type is arranged at the rim horn 18, the balancing weight consisting of two weight sections 22a and 22b. The weight sections 22a, 22b are connected by means of a hinge-like connecting element with each other so that they are pivotably about a hinge axis tangential to the rim axis. Weight section 22a is formed to grip over the end of the rim horn 18 while weight section 22b is pivoted so that it fits to the inner contour of rim horn 18.

The connecting element 24 in this embodiment consists of the double-adhesive tape 25, at the same time fixing the balancing weight to the wheel rim.

Figure 3 is a perspective partial view of an aluminum wheel rim 26 similar to figure 2 with a rim horn 28 to which, on the one hand, a self-adhesive balancing weight 30 according to the present invention is mounted, and, on the other hand and in comparison therewith, a conventional clip-on-balancing weight 32. The balancing weight 30 as in figure 2 consists of two weight sections 30a and 30b, which are pivotably connected one to the other by means of a hinge-like connecting element 32 made of a double-adhesive tape 31. The weight section 30a grips over the end of rim horn 28 while weight section 30b fits to the inner contour of rim horn 28 owing to the flexible connecting element 32. The balancing weight 30 according to the present invention allows to mount most of the mass of the balancing weight radially far outward so that its effective mass may be less than the mass of a conventional clip-on balancing weight 34 with its effective mass further inward. Figures 4 and 5 show in comparison, how the same balancing weight having two pivotably connected weight sections 12a, 12b and a common adhesive tape 12c, is attached to rims having different shaped rim horns. In figure 4, the rim horn has a comparatively small radius. Accordingly, the weight sections are close to each other, forming a smaller outer radius. In figure 5, the rim horn has a larger radius. Therefore, the weight sections are distant to each other, forming a larger gap between the weight sections and resulting in a larger outer radius. Adapting the gap between the weight section allows to adapt the outer contour to different rim horn geometries.

Figure 6 is a radial partial sectional view of a steel wheel rim with a chain of self- adhesive balancing weights arranged in a rim horn. A plurality of segmented and pivotably connected balancing weights are arranged to a chain of balancing weights resulting in a larger mass. Preferably, the balancing weights have a common adhesive tape.

In figure 7 a balancing weight with extensions for simplified handling is shown. These extensions 12e are at the sides of the weight sections 12a, 12b, close to the top surface of these weight sections. There is no adhesive tape 12c, 12d on these extensions. It is preferred, it the extensions have the same or less thickness than the adhesive tape. It is difficult to handle a balancing weight without these extensions, as a person who would pick up a balancing weight would need to hold it between two fingers at opposite sides of the balancing weight. Therefore, there is a high probability, that the balancing weight would stick to the persons fingers by its adhesive tape. The same problem would arise by handling by a robot. With the extensions 12e, two non— sticking surfaces are provided at opposite sides of the balancing weights, which simply can be gasped by a person or by a robot.

In figure 8 another embodiment of the balancing weight is shown which can be inserted into an edge of a rim with a comparatively small radius. Here, the rim 41 of a wheel forms approximately a right angle. The two balancing the weight sections are different in shape and size. A smaller section 12a is close to the edge of the rim, while the other section is distant thereof. Due to the gap between the sections, the balancing weight may be bent and adapted to the angle of the rim.

In figure 9, a flexible adhesive tape 12f for balancing weights as described above is shown. Individual section 4 individual balancing weights are formed by a perforation in the tape. This perforation may comprise a serious of holes or slots.

It allows for easier separation of balancing weights and it allows for easier bending. As it can be seen from figure 6, the balancing weights are adapted by the flexible sections to the small rim radius of the wheel. Furthermore, they have to be bent in a second axis to adapt to the outer time later of the wheel, which may be in the range from 15 to 22 inches. Such a slight banding is allowed by extending the perforation. In figure 10 a more flexible adhesive tape 12f is shown. There is a plurality of cuts 12h on both sides of the adhesive tape forming individual sections for the balancing weights. Due to the opposing cuts, only a small connecting section between the individual adhesive tape sections remains, which can be easily bent in the plane of the drawing.

In figure 11 a further embodiment is shown. Here two balancing weight sections 13a and 13b are connected by the self-adhesive tape 12c. Furthermore, it is preferred, if at least one of the balancing weight sections 13b has a chamfered edge for sliding or pivoting against the other balancing weight section. In figure 12 a slightly modified embodiment is shown. Here, one of the balancing weight sections 13b has a rounded edge 13c for sliding or pivoting against the other balancing weight section.

In figure 13 a further modified embodiment is shown. Here, both balancing weight sections 13a, 13b have rounded edges 13d, 13c for sliding or pivoting against the other balancing weight section.

List of reference numerals

2 wheel rim

4 wheel disk

6 wheel band

8 wheel horn

10 tire

12 balancing weight

12a weight section

12b weight section

12c adhesive tape

12d adhesive tape

12e extensions

12f flexible adhesive tape

12g perforation

12h cut

13a weight section

13b weight section

13c rounded edge

13d rounded edge

14 connecting element

15 ap

16 wheel rim

18 rim horn

20 tire

22 balancing weight

22a weight section b weight section connecting element adhesive tape wheel rim rim horn balancing weighta weight sectionb weight section adhesive tape connecting element balancing weight