FIELD OF THE INVENTION.
[001] The present invention relates generally toward a method for coating cast alloy wheels. More particularly, the present invention relates to a method to manufacture a dual tone alloy wheel to achieve a unique dual-tone color appearance. 5
BACKGROUND OF THE INVENTION
[002] Alloy wheels are wheels that are made from an alloy of aluminium or magnesium. Alloys are mixtures of metal and other elements. They generally provide greater strength over pure metals, 10 which are usually much softer and more ductile. Alloys of aluminium or magnesium are typically lighter for the same strength, provide better heat conduction, and often produce improved cosmetic appearance over steel wheels.
15
[003] Cast alloy wheels have been increasing in market share for many years. They provide both weight reduction and unique appearance not available to old style steel wheels decorated with hubcaps. The methods for providing a durable and aesthetically pleasing coating to cast alloy wheels have varied widely. Early 20 versions of cast alloy wheels were coated with lacquer paint, which provided aesthetically pleasing qualities, but did not provide necessary durability. Later generations of cast alloy wheels were coated with multi-layer paint systems that included primers, colorization or base
3
coats, and a clear coat to provide a high level of gloss to the alloy wheel.
[004] In some instances, the paint coatings are removed so that the substrate of the cast alloy is exposed to achieve a unique, “bright metallic surface” over which a clear coat is applied. 5
[005] Traditionally, the alloy wheels were manufactured having a single color, however over the period of time, the companies have started selling the vehicles with dual tone Alloy wheels.
10
[006] Currently, dual tone alloy wheels are manufactured using the following methods:
[007] 1. Laser Etching Method:
Primer coat and base coat of two desired colors are applied to the 15 aluminium substrate respectively and with the help of laser, the desired areas of the base coat are etched, resulting in a dual tone alloy wheel. Once, the base coat is removed using laser etching, a coat of clear material is applied to the dual tone alloy wheel for protection.
20
[008] The above method is very precise however it has certain drawbacks such that it requires highly sophisticated modern technology machinery and is very expensive.
[009] 1. Manufacturing dual tone alloy wheels using Machining 25 method:
4
This method is somewhat similar to laser etching method. The only difference being that in this method, the base coat is removed using machining process rather than laser etching.
[010] The above method is very precise however it has certain 5 drawbacks such that it requires highly sophisticated modern technology machinery making it very expensive and needs longer process time.
[011] 1. Manufacturing dual tone alloy wheels using external sticker 10 pasting method:
In the above method, the aluminium substrate of alloy wheel is coated with primary and secondary coating. (one of the desired color) the secondary coating has desired base color of wheel. Following this, a coat of clear material is applied to the dual tone alloy wheel for 15 protection and finally a sticker of second desired color and pattern is pasted on the alloy wheel to produce a dual tone alloy wheel.
[012] The above method has following disadvantages:
a. The sticker is susceptible to damage and it peels of easily 20 since it is pasted externally.
b. The finishing is not very good and aesthetically not upto the mark.
c. It has a less durability as there is more chance of sticker peeling out. 25
5
[013] US20170129279 (D1) discloses a method of coating a cast alloy wheel providing it a two-tone appearance. According to D1, a cast alloy wheel includes a primary and a secondary surface, over which a first polymeric coating is applied to seal the cast alloy wheel within the first polymeric coating. It is followed by the coating of an 5 intermediate polymeric coating with metal over first polymeric coating using Physical Vapour Deposition (PVD) technique, so that the metallic coating is aesthetically distinguishable from the first polymeric coating. A third polymeric coating is applied over the metal. Further, the third polymeric coating, intermediate polymeric 10 coating and metallic coating are removed aesthetically to distinguish the primary surface from secondary surface. Lastly, a fourth polymeric coating is applied over the primary and the secondary surface.
15
[014] The method as disclosed in D1 is very tedious, time consuming and expensive. Further, it uses PVD technique and metallic coating using PVD technique. The metal adds extra weight to the alloy wheel and also increases the overall cost. Further, the method as described in D1 requires highly sophisticated machinery and set up and an expert’s 20 supervision.
[015] TW200840653A (D2) discloses a color-combined wheel rim sputtering process wherein surface color painting is applied to the front surface of the wheel rim with a protective marking cover is 25
6
arranged on the ribs so that the coating of a layer of medium paint is effective on the recessed potions of the font surface of the wheel rim.
[016] D2 involves a process called “sputtering” in which thin film is deposited onto substrate. In this process deposition is applied, by using 5 electrical energy. Broadly, this process is similar to chrome plating, with difference that deposition is selective in this case.
[017] The method as disclosed in D2 requires D1 requires highly sophisticated machinery and set up and an expert’s supervision and is 10 expansive and time consuming.
[018] Hence, there is a need for a cost effective method which requires less technical sophistication and is relatively easy for manufacturing of two tone (dual tone) alloy wheels yet meeting the 15 appearance criteria and durability
OBJECTS OF THE INVENTION
[019] It is therefore an object of the present invention to manufacture cost effective dual tone (two tone) alloy wheel using novel technique
20
[020] Another object of the present invention is to define a cost effective technique with ease of manufacturing to produce dual tone alloy wheel meeting required performance..
25
7
SUMMARY OF THE INVENTION
[021] The invention is related to a method of manufacturing of dual tone (two tone) alloy wheel. According to the present invention, an aluminium substrate is coated with a layer of Primary coat followed by a layer of anintermediatecoat. Further, a graphics sticker is pasted 5 over theintermediate coat which is finally coated by a top clear coat to give protection and better life.
[022] The primary coat and intermediatecoat may/may not be of the same color;however the graphic sticker is generally of different color 10 in order to produce a dual tone alloy wheel, thus the color graphics is integrated into paint system of alloy wheel providing a seamless finish
BRIEF DESCRIPTIONS OF THE ACCOMPANYING DRAWINGS 15
[023] The above brief description, as well as further objects, features and advantages, of the present invention can be fully appreciated by reference to the following detailed description. These features of the present invention will become more apparent upon reference to the drawings, wherein: 20
[024] Fig. 1: Method of manufacturing a dual tone alloy wheel using laser etching method
[025] Fig. 2: Method of manufacturing a dual tone alloy wheel using machining method
8
[026] Fig. 3: Method of manufacturing a dual tone alloy wheel using external sticker painting method
[027] Fig. 4 & 5(A): Method of manufacturing a dual tone alloy wheel using the present invention
[028] Fig. 5(B): A finished Dual Tone alloy wheel using the present 5 invention
DETAIL DESCRIPTION OF THE INVENTION
[029] The present invention will be described in detail below with reference to an embodiment as shown in the drawing.
[030] The method of the present invention provides a streamlined 10 process of dual tone coating of an alloy wheel, over that of prior arts while simultaneously enhancing durability of the alloy wheel (10).
[031] Referring to Figure 4, said alloy wheel (10) is shown.Said alloy wheel (10) is formed via a conventional forming method and includes a machined face (12) of the wheel to form a "bright machined" 15 surface.
[032] Said alloy wheel (10) also includes three- dimensional configuration having recessed surfaces that define side of the wheel spokes and visible portions of a wheel rim.
[033] Referring to Fig. 4& 5, the method of manufacturing said dual 20 tone alloy wheel (10) according to the present inventionis described.
[034] An aluminium substrate (20) is first coated with a primary coating (25). Said aluminium substrate with a coating of said primary coat (25) is allowed to dry for stipulated time.
9
[035] Subsequent to the primary coating and drying, said aluminium substrate (20) is coated with anintermediate coat (30) to make a wheel surface (50). Said wheel surface is allowed to dry preferably for stipulated time.
[036] Said intermediate coat, includes pigments for color and 5 metallic flakes to add visual depth to the three-dimensional surface of said alloy wheel (10) to further enhance the aesthetics of said wheel(10).
[037] Said primary (25) and said intermediate coat (30) are preferably of same color, however they may differ as per the need. 10
[038] A graphic sticker (35) of desired pattern and color is cut out and pasted on said wheel surface (50) to produce a dual tone effect to the alloy wheel (10). Said graphic sticker (35) is pasted on said wheel surface (50) with the use of adhesive which is selected from a group of, cyanoacrylate adhesives, hot glue, Pressure Sensitive Adhesives, 15 Spray Adhesives, Fabric Adhesives, Epoxy, Polyurethane etc.
[039] Said sticker (35) is made from material selected from White Vinyl, Clear Vinyl, Reflective Vinyl, Paper, and Chrome BOPP.
[040] In order to protect said graphic sticker (35) and to increase the life of dual tone alloy wheel (10), a coat of clear material (40) is 20 applied.
[041] The invention has been described in an illustrative manner, and it is to be understood that the terminology that has been used is intended to be in the nature of words of description rather than of limitation. Obviously, many modifications and variations of the 25 present invention are possible in light of the above teachings. It is
10
therefore to be understood that within the specification, the reference numerals are merely for convenience, and are not to be in any way limiting, the invention may be practiced otherwise than is specifically described.

WE CLAIM:
1. A methodto manufacture a dual tone alloy wheel (10), wherein
Applying a primary paint coat to an aluminium substrate (20);
Applying an intermediate paint coat to said aluminium substrate (20) to produce a colored wheel surface (50); 5
Pasting a graphic sticker (35) on said wheel surface (50);
Applying a third coat to said graphic sticker (35) pasted on said wheel surface (50) to obtain said dual tone alloy wheel (10).
2. The method as claimed in claim 1 wherein said step of applying 10 a first paint coating is defined as applying a primary coating (25);
3. The method as claimed in claim 1 wherein said step of applying a second paint coating is defined as applying a intermediate 15 coating (30);
4. The method as claimed in claim 1 wherein said step of applying a third coating is defined as applying a clear coating (40);
20
5. The method as claimed in claim 1 wherein, said first paint coating and said second paint coating can be of same color or different colors.
6. The method as claimed in claim 1 wherein, said sticker is made 25 from material selected from White Vinyl, Clear Vinyl, Reflective Vinyl, Paper, and Chrome BOPP.
12
7. The method as claimed in claim 1 wherein, said sticker (35) is pasted on said wheel surface using adhesives selected from, but not limited to cyanoacrylate adhesives, hot glue, Pressure 5 Sensitive Adhesives, Spray Adhesives, Fabric Adhesives, Epoxy, Polyurethane.