Patent Application
20050242656
The present invention relates to vehicle wheel assemblies that include decorative wheel covers which are secured to underlying wheels. More specifically, the present invention relates to methods for producing decorative wheel covers that have formed edges and particularly to methods for reducing the sharpness of the formed edges.
Wheel assemblies that utilize wheel appliques to decorate the external or outboard surfaces of plain steel wheels are well known and are far less expensive to produce than one-piece decorative wheels that have to be formed and finished. Wheel appliqués or covers can be secured to the outboard surfaces of wheels by a variety of adhesive materials that are applied as continuous layers or discrete patterns between the inboard surface of the wheel covers and the outboard surface of the wheels. Alternatively, or in addition to the use of adhesive materials, various mechanical means including clips, fasteners, biased engaging structures, etc. can be used to secure wheel covers to wheels.
Decorative wheel covers are typically made from metal stock or molded from plastic materials. In all cases the wheel covers have finished outboard surfaces that may be painted, textured or plated, e.g. chrome plated, as desired. The use of plastic materials has gained popularity recently because plastics are easy to mold into complex profiles associated with decorative wheels that include various configurations and combinations of spokes or spiders and openings or windows that are decorative and/or functional.
Notwithstanding the ease of manufacturing and lower material cost associated with plastic decorative wheel covers, there are preferences to using metal wheel covers including the fact that in some applications metal wheel covers can feel and sound more solid than plastic wheel covers after being assembled to a wheel. In particular, metal wheel covers that are attached to wheels tend to have a metallic sound when tapped or struck whereas plastic wheel covers tend to have a dull or muted sound in similar circumstances. The impression which is not necessarily justified is that wheel assemblies having metallic wheel covers are metal and solid whereas wheel covers having plastic wheel covers are laminated articles which are not as solid.
Metal wheels are generally not cast or injection molded. Rather they are formed using metal fabrication techniques such as stamping, punching, cutting, pressing, bending, drawing, etc. Unlike plastic materials that can be molded, there are physical limitations imposed on the ability of metals to be fabricated into certain shapes. For example, if a wheel cover design has a profile height that is extreme or if the design includes a profile that has complex bends, it might be physically impossible to work a stock sheet of metal to conform to such a design profile.
Because of such concerns, designers have found it necessary to limit the complexity of designs for decorative wheel that are to be made from metals.
The present invention involves wheel cover designs that push the limits on the formability of metals used to fabricate wheel covers. The present invention moreover addresses and solves problems that arise from such advanced designs.
According to various features, characteristics and embodiments of the present invention which will become apparent as the description thereof proceeds, the present invention provides a method of forming a decorative wheel cover that is configured to be attached to a vehicle wheel which method involves:
The present invention further provides for a decorative wheel cover that includes:
The present invention further provides a wheel assembly that includes:
The present invention also provides for a method of dulling sharp edges formed on a decorative wheel cover which involves:
In general, the present invention provides for decorative wheel covers that are plated in such a manner to dull any sharp edges that are produced during the formation of the wheel covers.
The present invention will be described with reference to the attached drawings which are given as non-limiting examples only, in which:
The present invention relates to methods for producing decorative wheel covers that have formed edges and particularly to methods for reducing the sharpness of the formed edges. In use, the wheel covers are attached to the outboard side of a wheel to produce a wheel assembly with a decorative finish. The present invention allows wheel cover designers and manufacturers to push the limits on the formability of metals used to fabricate wheel covers. Moreover, the present invention addresses and solves problems that arise from such advanced designs.
During the course of the present invention, the inventor experimented with the limits to which stock metals could be formed into decorative metal wheel covers. In particular, metal wheel covers were fabricated using conventional metal forming processes into designs having profile features which required the metal to be worked to theoretical limits. As the extremes of the design profile features increased, e.g., as the height and/or shape configuration between reference points increased requiring the metal to be worked further, portions of the metal became thinner. In the case where the metal became thinner at free edges such as the edges of openings or windows, sharp edges developed which required further processing to dull the shape edges.
Accordingly, the present inventor has discovered that although it is possible to work metal stock during fabrication of more complex or extreme decorative wheel cover designs, an issue arises as to how to treat any sharp edges that are formed on the metal wheel covers.
It is common practice to plate the outboard side of metal (and plastic) wheel covers to produce a desired finish. A common plating material is nickel-chrome which provides the outboard side of a wheel cover with a chrome finish. The present inventor has learned that when metal wheel covers are plated on their outboard surfaces with a material such as nickel-chrome, the plating material builds up on trimmed edges of the wheel covers.
When, according to the present invention, stock metal is worked to fabricate more complex or extreme decorative wheel cover designs, the present inventor has determined that subsequent plating of the outboard side of the wheel covers is ineffective to sufficiently dull sharp edges of the wheel cover. Moreover, the present inventor has further determined that increasing the thickness of the platting on the outboard surface of the wheel covers alone does not dull sharp edges of the wheel cover sufficiently.
According to the present invention, the inventor has discovered that plating both the outboard and inboard sides of the wheel covers effectively dulls any sharp edge created when metal wheel covers are formed.
Wheel 2 is of the type which includes a small central opening 5 in the wheel hub 6 and a plurality of exposed lug nut apertures 7 arranged in a circular pattern and spaced for the particular vehicle on which wheel assembly 1 is to be employed. Opening 5 will typically be enclosed by a relatively small cap while the lug nuts themselves (not shown) are exposed once the wheel assembly 1 is mounted to a vehicle.
Wheel cover 3 has a geometry and contour which substantially conform to that of wheel 2, namely, an outer peripheral edge 8 which matingly fits within rim 9 of wheel 2. Spokes 11 extend radially outwardly from the center hub opening 5 which correspond in size, shape and location to the spokes 10 on wheel 2. Between the spokes 11 of wheel cover 3 are decorative openings or windows 12 that are shaped to conform to corresponding decorative openings or windows 13 in wheel 2. The central hub area surrounding central opening 14 of wheel cover 3 also includes a plurality of lug nut receiving openings 15 which align with and are received within openings 7 in wheel 2 when the wheel cover 3 is position on the wheel 2. The central opening 14 of the wheel cover 3 is aligned with opening 5 in wheel hub 6, as best seen in
The wheel cover 3 is bonded to wheel 2 by an adhesive that securely bonds the wheel cover 3 to the outboard face of the wheel 2. The adhesive can be applied in any desired pattern or as a continuous layer. Alternatively, or in addition, to the use of an adhesive, various known mechanical engaging structures can be used to secure the wheel covers 3 to the wheels 2, including spring biased structures, clips, fasteners, etc.
Although the present invention was primarily developed to advance the fabrication and design of metal wheel covers including stainless steel wheel covers, it has also been determined during the course of the present invention that wheel covers made of solid panels of high-impact plastic materials can have both their outboard and inboard sides plated to dull any sharp edges. An advantage of using a high-impact plastic material such as a combination of polycarbonate and ABS having is that wheel covers 3 made from such materials can be injection molded. However, in certain applications and configurations, plastic wheel covers do not always feel and sound as solid as metal wheel covers.
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The edges of the wheel covers produced by the two-sided plating process were rounded sufficiently to eliminate sharp edges.
While the plating processes described above were controlled in a conventional manner set to deposit 25 microns of total nickel thickness and 0.25 microns of chromium on the front, outboard or “A” side of the wheel covers, it was discovered that the thickness of the overall plating was about 1-13 microns along the brake vent window edges in the wheel covers that were only plated on one side. However, it was discovered that plating both sides of the wheel cover to deposit 25 microns of total nickel thickness and 0.25 microns of chromium on the front, outboard or “A” side of the wheel covers, resulting in a overall plating thickness of 60 microns per side at the edges of the brake vent windows. Although not professing to be held to any explanation, this phenomenon is believed to be due in part to magnetic fields that are created in the plating bath during the plating process because of the configuration of the wheel covers.
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Although the present invention has been described with reference to particular means, materials and embodiments, from the foregoing description, one skilled in the art can easily ascertain the essential characteristics of the present invention and various changes and modifications can be made to adapt the various uses and characteristics without departing from the spirit and scope of the present invention as set forth in the following claims.
