This invention relates generally to a method to manufacture buttons. In particular, this invention relates to a method to manufacture a button using a two shot molding process.
It is well known in the art to use a plurality of buttons on instrument panels within a vehicle wherein those buttons have chrome plating. These buttons commonly require a plurality of elements to be joined together after certain elements have received chrome plating. As shown in
Fitting a plurality of elements together to form a button having a light pipe and a chrome plated element is difficult to produce, costly, and creates a plurality of problems. The gap created between the light pipe 24 and the main housing 22 produces rattling or other noise creating a common complaint by the user. Furthermore, the gap created between the main housing 22 and the light pipe 24 frequently allows light to escape before it is filtered through the light pipe 24. This escaping light produces an undesirable appearance on the radio. Accordingly, it is desirable to inexpensively produce a chrome button having an integrated light pipe with improved fit and finish.
The present invention provides a method for molding and chrome plating a button having an integrated light pipe. The method utilizes a two shot molding process to create the button housing and the light pipe. The method includes the steps of injecting a first shot of resin A wherein resin A is a resin not allowing chrome to adhere to it, allowing resin A to cool, injecting a second shot of resin B into the mold, and continuing to chrome plate the entire button wherein chrome only adheres to resin B. A light pipe formed by resin A remains transparent or translucent allowing light to shine through from a light to the eye of a user. Chrome plating adheres to resin B providing for a polished finish.
This invention provides for a method using a two shot molding process to create a button for a radio assembly wherein the two shot process creates a button housing and a light pipe using two different resins wherein chrome plating only adheres to one of the resins. The two shot molding process creates a polished and finished look of the chrome, eliminates noise heard by the user, and eliminates the subassembly of the button housing and the light guide to provide for easier manufacturing processes.
A radio assembly 10 is provided having a plurality of buttons 16, as shown in
As an example of the present embodiment, the resin used to create the housing 16 is polycarbonate/ABS blend. Furthermore, the resin used to create the light pipe 14 is polypropylene (PP). During the chrome plating process, chrome does not stick to the polypropylene (PP) used to make the light pipe 14. Furthermore, during the chrome plating process, chrome does stick to the polycarbonate/ABS blend used to make the housing 16.
The resin used to create the light pipe 14 must be a resin not allowing chrome to stick to the resin. The resin used in a light pipe 14 is typically a clear resin having transparent or at least translucent qualities.
As shown in
As shown in
The housing 12 includes a first surface 48. The first surface 48 is opaque and chrome plated so as not to allow any light to pass through. The first surface 48 faces the user of the buttons 16. The housing further includes an arm 42 allowing easy installment of the button assembly 50 into a radio. The housing 12 further includes a second surface 40. The second surface 40 faces the light source 52.
The light pipe 14 may be filled completely or open as shown by the open space 44. In an alternative embodiment, the open space 44 is filled with a clear resin which allows light from the light source 52 to pass through.
The method according to the present invention is illustrated in the flowchart as shown in
In an alternative embodiment, the molding process may include the first shot of the resin to form the button housing first, allow the resin used for the button housing to cool, and then completing the button assembly with a second shot of resin to form the light pipe. The order in which the two button assembly subparts are molded is negotiable.
The invention is not restricted to the illustrative examples and embodiments described above. The embodiments are not intended as limitations on the scope of the invention. Methods, apparatus, compositions, and the like described herein are exemplary and are not intended as limitations on the scope of the invention. Changes therein and other uses will occur to those skilled in the art. The scope of the invention is defined by the scope of the claims.