Patents by Inventor Friedhelm Wallenhorst

Friedhelm Wallenhorst 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).

  • Chemical gilding bath
    Patent number: 4481035
    Abstract: A chemical gilding bath is formulated on the basis of an alkaline, aqueous solution of an alkali gold cyanide complex and has a reducing agent and a stabilizing agent therein. The reducing agent is an organic compound containing at least one enol group within the molecular structure thereof, such as ascorbic acid or salts thereof. The pH value of the bath is adjusted by a buffer solution so as to range between about 7.5 to 12 and preferably is about 8.
    Type: Grant
    Filed: August 25, 1983
    Date of Patent: November 6, 1984
    Assignee: Siemens Aktiengesellschaft
    Inventors: Ernst Andrascek, Hans Hadersbeck, Friedhelm Wallenhorst