Patents by Inventor Ruth E. Stephens

Ruth E. Stephens 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).

  • Process for preparing filled polyvinyl chloride compositions
    Patent number: 4210574
    Abstract: A process for preparing polyvinyl chloride compositions containing talc or kaolinite fillers.
    Type: Grant
    Filed: May 22, 1978
    Date of Patent: July 1, 1980
    Assignee: Ethyl Corporation
    Inventor: Ruth E. Stephens
  • Process for preparing filled polyvinyl chloride compositions
    Patent number: 4132700
    Abstract: A process for preparing polyvinyl chloride compositions containing talc or kaolinite fillers, which have been pretreated with an acid wash solution.
    Type: Grant
    Filed: February 4, 1976
    Date of Patent: January 2, 1979
    Assignee: Ethyl Corporation
    Inventors: Ruth E. Stephens, deceased, by William L. Stephens, executor
  • Exhaust catalyst
    Patent number: 3983072
    Abstract: Engine exhaust gas is rendered less noxious by contact with a catalyst consisting essentially of manganese oxide and palladium on a suitable support such as alumina. Optionally, the support may be precoated with a rare earth metal oxide to improve catalyst hardness.
    Type: Grant
    Filed: April 16, 1973
    Date of Patent: September 28, 1976
    Assignee: Ethyl Corporation
    Inventor: Ruth E. Stephens