Patents by Inventor Willi Befeld

Willi Befeld has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4737245
    Abstract: A method for electrolytically coloring anodized aluminum and aluminum alloys in a reproducible manner so that they are of uniform color is provided. The anodized aluminum or aluminum alloy is anodically treated and then electrolytically colored in a solution capable of forming a barrier layer. Prior to the anodic treatment, the counterelectrodes are activated using a direct voltage of 2 to 9 volts between the counterelectrodes, as anodes, and auxiliary electrodes, as cathodes. The process includes the additional step, after anodic treatment and prior to coloring, of maintaining the aluminum or aluminum alloy for a currentless waiting time of from 0.5 to 5 minutes in the treatment solution.
    Type: Grant
    Filed: August 27, 1986
    Date of Patent: April 12, 1988
    Assignee: Chemal GmbH & Co. KG
    Inventor: Willi Befeld