1. 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.
2. Description of Relevant 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.
US 2007/0108834 A1 discloses a balancing weight body filled with mass material particles.
FR 1.309.852 discloses a balancing weight with a curved attachment section.
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 exist two basic concepts. Self-adhesive balancing weights usually have a planar back surface which is designed 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.
The embodiments are directed to providing self-adhesive balancing weights configured to fit to rims of several different shapes. Therefore, a situation is achieved when only a small number of balancing weights or only a single type of balancing weights are configured to fit to a broad variety of rims.
For finding a solution of the problem, a large number of rims have been analyzed and checked for appropriate locations for mounting of balancing weights. It was discovered that a balancing weight that fits to most rims on the market, possesses the following features.
A balancing weight has a top surface that in practice may be configured to have any shape, but preferably is a planar surface. Approximately opposed to the top surface there is a bottom surface, which is preferably designed to be held to the rim by means of a self-adhesive tape. The self-adhesive tape preferably is attached to the bottom surface or parts or portions thereof. In an alternate embodiment, the balancing weight may be held to the rim by means of a clip. Furthermore, it is preferred that the balancing weight have at least one or two extensions, by which the balancing weight may be held by a robot or a person when the balancing weight is attached to a rim.
The bottom surface, which also serves as an attachment surface, has at least two curved surface portions or sections with different radii. There is a first curved surface portion or section having a first radius and a second curved portion or section having a second radius. Between the first and second curved surface portions or sections (first and second curved sections, for short) and the top surface of the balancing weight or the extensions of the balancing weight, there may be present an approximately straight section or a plurality of straight sections, which either preferably have a comparatively large curve radius (that is significantly larger than that of the second curved section), or are straight. Although in one embodiment, the first curved section is located next to the second curved section, in an alternate embodiment, there may be a straight section between the first curved section and the second curved section. At the first curved section, opposite to the second curved section, there may be a third curved section.
The radius of the first curved section is smaller than that of the second curved section. The first and/or the second curved sections may have notches or recesses for further enhancement of affixation to the rim. The radius of the third curved section may be smaller than the radius of the first curved section, but it is preferred to have a larger radius. Preferably, the radius of the third curved section is the same as the radius of the second curved section, while both of these radii are larger than the radius of the first curved section.
Preferably, a recess is provided within the first curved section. The recess may have the shape of a flat blind hole. The recess may be circular, rectangular or have any other shape. The area of a cross section of the recess may be between 50% and 10% of the surface area of the first curved section. The depth of the recess may be between 1 mm and half of the thickness of the balancing weight. The presence of the recess results in a lowered/reduced surface area of the first curved section. Due to the lowered surface area, the total force required to compress an adhesive tape located at the first curved section is smaller as compared to a similar force associated with the second and the third section. This helps to adapt the balancing weight to rims when the shape of the rim is such that the distance between the rim and the first section is smaller than the distance between the rim and the second and/or third sections, requiring a higher compression at the first curved section.
It is further preferred, if the length of the second section is larger than the length of the first section. It is furthermore preferred, if the length of the third section is smaller than the length of the first section.
Preferably, the first, second and third curved sections are convex shaped (or convex, for short).
It is preferred, if the self-adhesive tape is disposed on the first curved section and on the second curved section. In this case, the self-adhesive tape is disposed to preferably cover the first curved section and the second curved section in a tangential direction. Most preferably, the self-adhesive tape (optionally completely) covers the first curved section and the second curved section in a tangential direction (that is, in a direction of an axis that is tangential to a given curved section).
There may be one or two additional curved sections limiting the extent of the bottom surface against the top side. These additional curved sections are different from the first curved section and the second curved section.
Most preferably, the first and second curved sections form contact points with a rim and such contact points define at least a contact line (a line of contact with a rim). There is a contact established between the balancing weight and the rim over the length of the balancing weight at these contact points. The contact may even be formed at a larger contact area, if the curvature of the rim is very similar to the curvature of the bottom surface of the balancing weight. If there are only small deviations/differences between these two curvatures, or a small variation in distance between the rim and the balancing weight, such differences and/or deviations will be compensated by the adhesive tape. In the use of an embodiment of a balancing weight configured for use with the rims made of aluminum, there may be established at least one contact line or even a contact area between the rim and at least one of the straight sections.
Herein, the terms “contact points” and “contact lines” are used. In a given sectional view of the balancing weight, the area of contact between the balancing weight and a rim may look like (appear to be) a point. However, there exists a projection of the contact point forming a contact line in the direction of the length of the balancing weight. In this document both terms “contact point” and “contact line” are used as equivalent to one another as described above.
Both curved sections result in at least two contact points, of the balancing weight with the rim, for a large variety of balancing weights, which results in a sufficient contact and a sufficient adhesive force to the rim. Due to the judiciously defined curves of the curved sections, the distance to the rim in case of any deviations of the form/shape of the rim is slightly decreasing. Such slight decrease of the distance may easily be absorbed or compensated for by a self-adhesive tape between the balancing weight and the rim, thereby resulting in a comparatively large section in which adhesive forces apply. Preferably, the first radius of the first curved section is about a half of the second radius of the second curved section. Preferably, the first radius is about 4 mm while the second radius is about 8 mm. These values may be modified in a range of ±50%, preferably within ±30%, and most preferably within ±10%.
In a related embodiment, preferably, the first radius of the first curved section is about ⅕ of the second radius of the second curved section. Preferably, the first radius is about 1.8 mm while the second radius is about 9 mm. These values may be modified in a range of ±50%, preferably within ±30%, and most preferably within ±10%. It is further preferred, if there are two straight sections between each of the first and second curved sections and the top surface. Preferably, the angle formed by such straight sections with one another is 90 degrees. Optionally, the angle may vary by less than ±30 degrees, preferably less than ±20 degrees, and most preferably less than ±10 degrees. Preferably, the first radius is by 1 mm smaller than the second radius which is 8 mm, with a tolerance of these two values of radii of ±50%, while the preferred tolerance is +/−30%.
Preferably, the center axis for the first radius goes or passes through (traverses) the balancing weight body, while it is preferred, that the center axis for the second radius (in one embodiment—an axis in which a center of the curvature is located) is outside of the balancing weight body.
The balancing weights may be made from any material as known from the art. The material preferably comprises zinc or steel. It is further preferred, if the balancing weights have at least one inlay of a ferromagnetic material, for example, iron or steel, which would allow the use of a magnetic picking head to handle the balancing weights.
In a preferred embodiment, there are gaps or cutouts at at least one side and preferably at both (opposing) sides of the self-adhesive tape, which allow easier bending of the tape to adapt to a radius of a rim. Such gaps or cutouts are preferably disposed between the balancing weights.
A further embodiment relates to a chain or a belt of balancing weights comprising a plurality of balancing weights configured as disclosed in this document. These weights are interconnected by the self-adhesive tape.
All the embodiments disclosed herein may be combined in any sequence.
In the following, the invention is described by way of examples, without limitation to the general inventive concept, and with reference to the drawings.
While embodiments of the invention can be variously modified and assume alternative forms, specific embodiments are shown by way of examples in the drawings and described in detail below. It should be understood, however, that the drawings and detailed description are not intended to limit the invention to the particular form disclosed, but on the contrary, the scope of the intention is to cover all modifications, equivalents and alternatives as recited in the appended claims.
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The larger sidewalls provide the balancing weight with additional height and, therefore, volume and mass. Such sidewalls further may allow to include an inlay or insert element 22 (comprising a ferromagnetic and preferably a soft magnetic material). The purpose of the use of inlay is to improve the handling of a weight by a magnetic handling apparatus. Preferred materials of this inlay are iron or steel.
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It will be appreciated to those skilled in the art having the benefit of this disclosure that this invention is believed to provide balancing weights for vehicle wheels. Further modifications and alternative embodiments of various aspects of the invention will be apparent to those skilled in the art in view of this description. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the general manner of carrying out the invention. It is to be understood that the forms of the invention shown and described herein are to be taken as the presently preferred embodiments. Elements and materials may be substituted for those illustrated and described herein, parts and processes may be reversed, and certain features of the invention may be utilized independently, all as would be apparent to one skilled in the art after having the benefit of this description of the invention. Changes may be made in the elements described herein without departing from the spirit and scope of the invention as described in the following claims.
2 wheel rim
4 wheel disk
6 wheel band
8 wheel horn
9 tire
10 balancing weight
11 bottom surface
12 top surface
13 first sidewall
14 second sidewall
15 first line
16 second line
17 self-adhesive tape
18 cutout
20 balancing weight
22 inlay
24 recess
25 front side
26 rear side
30 balancing weight
40 first radius
41 second radius
42 third radius
43 first curved section
44 second curved section
45 third curved section
46 first straight section
47 second straight section
48 side angle
50 first contact area
51 second contact area
Number | Date | Country | Kind |
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16156457 | Feb 2016 | EP | regional |
This application is a continuation of the pending International Application No. PCT/EP2017/053689 filed on 17 Feb. 2017, which designates the United States and claims priority from the European Application No. 16156457.0 filed on 19 Feb. 2016. The disclosure of each of the above-identified patent applications is incorporated herein by reference.
Number | Date | Country | |
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Parent | PCT/EP2017/053689 | Feb 2017 | US |
Child | 15999571 | US |