Patents by Inventor Helmut Hulsmann

Helmut Hulsmann 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: 5904786
    Abstract: A method is disclosed for applying phosphate coatings to surfaces of zinc, iron, aluminum, and the alloys thereof by wetting with a phosphatizing solution containing divalent cations and phosphate to form a liquid film, and subsequently drying on the liquid film wherein the metal surfaces are wetted with a phosphatizing solution, which is free from elements of sub-groups 5 and 6 of the Periodic Table, said phosphatizing solution containing:0.5 to 8 g/l nickel;2 to 20 g/l manganese;18 to 170 g/l of phosphate (calculated as P.sub.2 O.sub.5);and has an acid number of 0.4 to 0.8, such that after drying on, a phosphate layer having a weight per unit area of 0.3 to 3.0 g/m.sup.2, is obtained, where in the case of phosphatizing surfaces of iron, aluminum or the alloys thereof, the phosphatizing solution necessarily contains 0.5 to 5 g/l of zinc, and in the case of phosphatizing surfaces of zinc or zinc alloys the phosphatizing solution either contains zinc or is free from zinc.
    Type: Grant
    Filed: June 6, 1997
    Date of Patent: May 18, 1999
    Assignee: Metallgesellschaft Aktiengesellschaft
    Inventors: Thomas Wendel, Hardy Wietzoreck, Klaus Bittner, Peter Schiefer, Marcus Schinzel, Helmut Hulsmann