Patents by Inventor Ruth Helgren

Ruth Helgren 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: D256772
    Type: Grant
    Filed: May 4, 1978
    Date of Patent: September 9, 1980
    Inventor: Ruth Helgren