Patents by Inventor Wilhelm Kerckhoff

Wilhelm Kerckhoff 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).

  • Crane trolley
    Patent number: 4423685
    Abstract: A novel crane trolley has four guiding pulleys lying on opposed upper and lower guiding surfaces, arranged diagonally to eliminate the need for having eight guiding pulleys. On each side of the trolley are upper and lower guiding pulleys, with the lower in front on one side and the upper in front on the other side. The pulleys may be mounted under spring tension. Two such trolleys may be hinged together to support heavy loads.
    Type: Grant
    Filed: July 30, 1981
    Date of Patent: January 3, 1984
    Assignee: Mannesmann Aktiengesellschaft
    Inventor: Wilhelm Kerckhoff