Patents by Inventor Gerd Treitz

Gerd Treitz 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: 4228872
    Abstract: To enable use to be made of relatively thin sheet metal to be employed in the manufacture of a ladder which is formed by punching adjacent openings from the sheet to leave edge strips which are subsequently folded to form stiles and cross pieces which are twisted to form tread bodies, embossed corrugations are incorporated into the twisted metal portions between the tread bodies and the stiles, and stiffening cheeks along the edges of the tread bodies are folded below the said bodies, thereby to impart rigidity to the ladder structure. Additionally or alternatively, holes and/or further corrugations may be provided, and the stiles may, if desired, be of oval cross-section each with connecting cheeks along their facing edges.
    Type: Grant
    Filed: September 14, 1979
    Date of Patent: October 21, 1980
    Inventor: Gerd Treitz