Patents by Inventor Walter Zweifel

Walter Zweifel 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: 4235682
    Abstract: The solution for sealing anodic oxidized aluminum or aluminum alloys comprises basically an aqueous solution containing an addition of 0.1 to 2.5 g/l, made up of Agar-Agar and gelatine. the optimum pH value for the solution lies between 5.5 and 6.0.The sealing is carried out at a temperature between 90.degree. C. and the boiling point of the solution.
    Type: Grant
    Filed: August 20, 1979
    Date of Patent: November 25, 1980
    Assignee: Swiss Aluminium Ltd.
    Inventors: Fritz Schneeberger, Walter Zweifel, Hermann Weber
  • Patent number: 3963591
    Abstract: The present invention relates to an improvement of the method for electrolytic coloring of anodically produced oxide layers on aluminum and its alloys, by electrolytic treatment in a metal salt (Ni, Co, Cu) solution. It is characterized in that one establishes in the coloring electrolyte a content of 0.02 to 0.75 grams copper per liter. The method permit uniform and reproductible coloring to be undertaken in a simple manner.
    Type: Grant
    Filed: August 25, 1975
    Date of Patent: June 15, 1976
    Assignee: Swiss Aluminium Ltd.
    Inventors: Walter Zweifel, Fritz Schneeberger