Embodiments disclosed herein relate generally to an assembly for holding a workpiece for processing. Specifically, embodiments disclosed herein relate to an assembly used to electroplate a workpiece.
Some workpieces are processed to become items in an article of manufacture. In one exemplary process, a workpiece is electroplated to add chrome. This exemplary process is similar to that used to place a chrome finish on a bumper for a vehicle. To perform this process, a workpiece may be attached to a plating rack with at least one connector. The at least one connector may provide a substantially rigid joint of the workpiece and the plating rack. The plating rack and the at least on connector comprise one embodiment of an electroplating assembly.
Starting the chrome plating process, the workpiece and the plating rack are joined with the at least one connector, all of which are at ambient temperature. During this chrome plating process, the workpiece, the at least one connector and the plating rack are exposed to significant heat, such as within the range of 50° C. to 65° C. Then, the workpiece, the at least one connector and the plating rack return to ambient temperature, i.e. a thermodynamic cycle of electroplating. This thermodynamic cycle of electroplating may induce the workpiece to deform. In some cases, the substantially rigid joint provided by the at least one connector combined with the thermodynamic cycle of electroplating may cause the workpiece to warp as the workpiece is returned to ambient temperature. This warping may damage the workpiece thereby requiring additional processing to correct the workpiece.
It is desirable to provide an improved electroplating assembly.
Disclosed herein are embodiments of an electroplating assembly. According to one embodiment, an electroplating assembly holds a workpiece through a thermodynamic cycle of electroplating. The assembly comprises a plating rack that supports the workpiece. An electric bus bar is disposed on the plating rack. At least one connector joins the workpiece with the plating rack. At least one flexible support joins the workpiece with the plating rack.
This disclosure relates to an electroplating assembly 10, an embodiment of which is shown in
The electroplating assembly 10 generally comprises a plating rack 14, at least one connector 16 and at least one flexible support 18. The plating rack 14 includes a conductor, such an electric bus bar and the like, for conveying electric current to the workpiece 12. The at least one connector 16 can be substantially similar to a holder, a hanger and a hook currently used in electroplating. The at least one connector 16 includes a conductor for conveying electric current from the plating rack 14 to the workpiece 12. In some embodiments, an electric bus bar 19 comprising the plating rack 14 is electrically connected with the conductor comprising the at least one connector 16 such as by soldering or brazing. Compared to the at least one flexible support 18, the at least one connector 16 provides substantially rigid attachment of the workpiece 12 and the plating rack 14. A plating rack contact 20 is disposed at an end of the at least one connector 16 opposite to the end thereof connected to the electric bus bar 19. The plating rack contact 20 may be soldered or brazed to the end of the at least one connector 16.
The at least one flexible support 18 includes a conductive core 21, such as comprising beryllium copper wire and the like. A cover 24 is disposed around at least a portion of the conductive core 21. In some embodiments, the cover 24 comprises a polymer. In some embodiments, the cover 24 is at least one of chemically and electrically insulating. The cover 24 may be replaceable. One end of the conductive core 21 of the at least one flexible support 18 is electrically connected with the electric bus bar 19 comprising the plating rack 14 such as by soldering or brazing. A plating rack contact 22 is disposed on an end of the conductive core 21 of the at least one flexible support 18 opposite to the end thereof connected to the electric bus bar 19. The plating rack contact 22 may be soldered or brazed to an end of the conductive core 21.
A segment 26 of the at least one flexible support 18, e.g. a portion of the at least one flexible support 18 occupied by the cover 24, is fashioned, twisted, heat treated and/or folded into a spring-like shape. This configuration allows adequate attachment of the workpiece 12 to the plating rack 14 while permitting limited movement or distortion of the workpiece 12 when the workpiece 12 is exposed to temperatures inherent in electroplating as well as subsequent cooling of the workpiece 12 to ambient temperature, i.e. a thermodynamic cycle of electroplating. The segment 26 may be formed by extrusion, casting, progressive die stamping, CNC bending and the like to obtain an initial shape, and then at least one of age hardened and heat-treated using industry-accepted methods inherent to processing of spring copper and the like to set the configuration of the segment 26. Without the segment 26 of the at least one flexible support 18 joining the workpiece 12 to the plating rack 14, the thermodynamic cycle of electroplating may cause the workpiece 12 may warp unacceptably. Unacceptable warping of the workpiece 12 can add to costs associated with providing the workpiece 12 for subsequent use.
To reduce likelihood of unacceptable warping of the workpiece 12 due to the thermodynamic cycle of electroplating, the at least one connector 16 and the at least one flexible support 18 joins the workpiece 12 with the plating rack 14. Locations and numbers of the at least one connector 16 and the at least one flexible support 18 can be determined empirically, using computer-aided engineering and the like. The locations and numbers of the at least one connector 16 and the at least one flexible support 18 may depend on size, weight, and configuration of the workpiece 12. In this manner, the segment 26 allows controlled, consistent movement of the workpiece 12 during the thermodynamic cycle of the electroplating process. This reduces likelihood that the workpiece 12 warps unacceptably.
In another embodiment shown in