Patents by Inventor James L. Planck

James L. Planck 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).

  • Adjustable legs for ladder
    Patent number: 4029174
    Abstract: A ladder designed for standing upon an inclined or other uneven surface; the ladder in one design having a metal block secured to a lower end of each leg, each block having a threaded vertical opening in which a threaded extension is vertically adjustable, a lower end of the extension having plate with a skid-proof bottom.
    Type: Grant
    Filed: April 6, 1976
    Date of Patent: June 14, 1977
    Inventors: James L. Planck, George Spector