Patents by Inventor Frederick Alan Hoffstadt

Frederick Alan Hoffstadt 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 fluid loss cementing compositions
    Patent number: 3943996
    Abstract: Improved cementing compositions and their use in well cementing operations is disclosed, wherein methacrylamidopropyltrimethylammonium chloride polymers are used as fluid loss additives for aqueous hydraulic cement slurries.
    Type: Grant
    Filed: June 27, 1975
    Date of Patent: March 16, 1976
    Assignee: Calgon Corporation
    Inventors: Lawrence James Guilbault, Frederick Alan Hoffstadt
  • Low fluid loss cementing compositions
    Patent number: 3931096
    Abstract: Improved cementing compositions and their use in well cementing operations is disclosed, wherein methacrylamidopropyltrimethylammonium chloride polymers are used as fluid loss additives for aqueous hydraulic cement slurries.
    Type: Grant
    Filed: October 30, 1974
    Date of Patent: January 6, 1976
    Assignee: Calgon Corporation
    Inventors: Lawrence James Guilbault, Frederick Alan Hoffstadt