Apparatus and method for self adhesive balancing weight liner removal

An apparatus for removal of the liner of a self-adhesive balancing weight is disclosed. A stripper wheel or stripper belt is rotated in close proximity over the surface of a balancing weight, and interacting with the liner and pulling the liner off from the balancing weight by means of a plurality of teeth. The speed of the stripper wheel or stripper belt is slightly higher than the speed of motion of the balancing weight.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to methods and devices for dispensing weights used in vehicle ballasting applications, in particular for dispensing weights used in balancing automobile or other vehicle wheels.

2. Description of Relevant Art

In automotive wheel balancing, individual wheel balancing weights are applied to specific positions of a rim. Basically, two types of balancing weight are used. The first kind is a balancing weight which is attached by a clamp, as disclosed in the European patent EP 1 613 876 B1, while the second kind is fixed by means of a self-adhesive tape, as disclosed in U.S. Pat. No. 6,364,421 B1.

Both kinds of balancing weights are available in a plurality of sizes, resulting in different weights. When balancing a vehicle wheel, the correct size of balancing weight is selected and attached to the rim. Most balancing weights are supplied as bulk material in boxes, from which the required number of weights is manually taken.

This allows for a simple, comparatively cheap supply of balancing weights. The drawback is that the person who is taking the weights from the box may take a wrong weight, and therefore a further step of balancing is required. Furthermore, the process of taking the weights can hardly be automated. Therefore, other solutions as disclosed in WO 2008/103651 A1, using a continuous polymer tape, have been developed. This has the drawback that a solid balancing weight is significantly more robust and reliable than these continuous tapes.

SUMMARY OF THE INVENTION

The embodiments are based on the object of stripping off the liner from an adhesive tape of balancing weights without damaging the adhesive tape and further without damaging the metal surface of the balancing weight. Furthermore, peeling-off should be done automatically in large volumes for low costs. It should be reliable without residing fractions of the liner on the adhesive tape.

In an embodiment, the liner is removed by a stripper wheel which rotates over the metal surface of the balancing weight, in a close proximity to be in contact with the liner but not with the metal surface of the balancing weight. Preferably, the stripper wheel rotates at a speed similar to the speed of movement of the balancing weight. Most preferably, the rotation speed of the stripper wheel is slightly higher than the speed of movement of the balancing weight.

It is further preferred, if means for precise guiding of the balancing weight are provided. This improves reliability and repeatability of the stripping process and further prevents the stripper wheel to touch the metal surface of the balancing weight. Such means for guiding the balancing weight may be a pressure roller. Such a pressure roller may press the balancing weight against a surface which is further referred to as pressure plate. The pressure roller may be a single role or a belt-conveyer-like assembly having at least one, preferably two pulleys for moving the belt. Furthermore, an aspirator or a vacuum cleaning device may be provided for removing the liner from the stripper wheel.

In a further embodiment, instead of the stripper wheel, a stripper belt may be used. It may be driven by at least one, preferably two stripper pulleys. Instead of a wheel or a belt, any other device having teeth at its outside and rotating with a speed similar to the speed of movement of the balancing weight may be used. Preferably, the stripper wheel or stripper pulley has saw-tooth-like teeth, which are rotating in the direction of rotation, the direction of movement of the balancing weight.

In another embodiment, the direction of rotation of the stripper wheel or stripper pulley may be reversed together with a reverse order of the teeth, resulting in stripping off the liner before the stripping wheel or belt.

It is further preferred, if for supplying balancing weights to the liner removal unit, a belt conveyer is provided. Such a belt conveyer may bring up the force to push a balancing weight through the liner removal unit under the stripper wheel and/or stripper belt.

In a further embodiment, a plurality of stripper wheels or belts may be provided either in parallel and/or one after the other.

In a further embodiment, means for adjusting the stripper wheel or stripper belt in relation to the balancing weight may be provided. This may compensate for tolerances in the thickness of the balancing weight. The adjustment may be done by spring loading the stripper wheel or stripper belt, and therefore asserting a predetermined force on the balancing weight. An alternative embodiment would be to use a stripper wheel or stripper belt having a comparatively broad surface and small teeth on it, whereas the surface is smoothly lying on the surface of the liner, while the teeth penetrate into the liner. The surface may also be made of elastic material to perfectly adapt to deviations in the surface of the liner. An alternate embodiment would be to couple the stripper wheel or stripper belt with the pressure roller or at least one of the pressure pulleys. When a balancing weight with a certain thickness is guided through the pressure roller20, the pressure roller is lifted to height of the balancing weight, also causing the stripper wheel or stripper belt to be lifted to the same height. This may be done by some electronic controlling or by simple mechanical coupling.

The advantage of the embodiments is that the liner can be removed reliably. Furthermore, the liner may be removed at comparatively high speeds. This design allows comparatively small tolerances of the stripper wheel and/or stripper belt and means for guiding the balancing weight, which results in a comparatively small damage of the adhesive tape under the liner. Furthermore, a damage of the surface of the balancing weight can be completely avoided. This surface must not be damaged as corrosion may occur, starting at damaged sections.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

InFIG. 1, a liner removal unit is shown. For stripping off the liner42of a balancing weight body41, a stripper wheel31is provided. It is rotating in direction60which is the same as the direction of movement14of the balancing weight. The speed of rotation is similar to the speed of movement of the balancing weight. Preferably, the speed of rotation is slightly higher. The stripper wheel has teeth which interact with the liner41and42, and pull it away from the balancing weight. An aspirator32or a similar vacuum cleaning device further removes the liner42from the stripper wheel31. To prevent the balancing weight from being lifted up by slightly sticking to the liner, preferably the pressure device, almost preferably a pressure roller20is provided. Such a pressure roller may be a single roller. Instead, here a pressure belt23is driven by a pressure pulley21and diverted via auxiliary pulley22. Here, pressure builds up between the pressure roller20and pressure plate24. Pressure roller20may be used for precision control of the speed of motion of the balancing weight40, which therefore can precisely be adapted to the speed of the stripper wheel31or stripper belt33. Pressure to the balancing weights may also be asserted by the stripper wheel or its shaft, which may bend the balancing weight into a desired radius. The balancing weight is further guided by a sliding surface51. The balancing weight is fed into the liner removal unit by a belt conveyer10comprising of a belt11, a conveyer pulley12, and a support plate13.

FIG. 2shows a liner removal unit comparable to the unit shown in the previousFIG. 1. The main difference is that the stripper wheel31is replaced by a stripper belt33. Here, the stripper belt33has teeth36, which pull off the liner from the balancing weight. The stripper belt is moved by two stripper pulleys34,35.

InFIG. 3, a balancing weight is shown. A balancing weight body is made of a metal or a metal-plastic composition providing mass, and therefore taking the function of the weight. For fixing the balancing weight to a rim, an adhesive tape43is provided. For protection, the adhesive tape is covered by a liner42which must be peeled off before applying the balancing weight to a rim.

FIG. 4shows the adhesive tape in detail. The liner42is stiffer than the adhesive tape itself, while the adhesive tape consists of a comparatively elastic material. When the teeth of the stripper wheel or stripper belt penetrate through liner42, they also penetrate into adhesive tape43. Due to the elastic nature of this material, the teeth will make small cuts into this material instead of lifting the adhesive tape of the balancing weight body41. The liner42which is comparatively stiff, cannot completely be cut by the teeth, and therefore sticks to the teeth and can be removed.

FIG. 5shows a balancing weight40which is divided in a plurality of sections which can be separated as required.

InFIG. 6, a stripper wheel with teeth36is shown in a side view.

InFIG. 7, a stripper wheel is shown in a front view. Here, a first wheel disk37and a second wheel disk38, both having teeth36, are connected by a shaft39to rotate synchronously. It is obvious that any other number of wheel disks37,38may be attached to a stripper wheel. The same applies to stripper belts. The shaft39may have a diameter slightly smaller than the wheel disks to prevent a deeper penetration of the wheel disks into the adhesive tape.

LIST OF REFERENCE NUMERALS