Patents by Inventor Clare J. De Graaf

Clare J. De Graaf 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).

  • Low profile chair iron
    Patent number: 4189179
    Abstract: A low profile chair iron for controlling biased tilting between a seat or backrest and a support uses a substantially flat coil spring of increasingly smaller diameter coils between pivotably connected support bracket and a chair part bracket. Tension adjusting means for the spring are pivotably mounted with respect to the central coils of the spring and/or support bracket for minimizing nonuniform loading of the spring during the pivotable movement of the chair part bracket with respect to the support bracket.
    Type: Grant
    Filed: June 4, 1976
    Date of Patent: February 19, 1980
    Assignee: Gordon Manufacturing Company
    Inventor: Clare J. De Graaf