Patents by Inventor Emil Freiwald

Emil Freiwald 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).

  • Foldable ladder
    Patent number: 4842099
    Abstract: A foldable ladder has collapsible crosspieces having a 90-degree pivot in the middle, the crosspieces being mounted to opposite side rails likewise having 90-degree pivots. Push rails are provided to the right and left of the crosspiece inside each sidepiece so as to move the ladder between folded and depolyed positions.
    Type: Grant
    Filed: December 10, 1987
    Date of Patent: June 27, 1989
    Assignee: Emil Freiwald
    Inventors: Dieter Collet, Emil Freiwald