Patents by Inventor Peter A. Howell

Peter A. Howell 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).

  • Glass bubbles of increased collapse strength
    Patent number: 4391646
    Abstract: Glass bubbles of increased collapse strength are prepared. The bubbles have an average particle density of 0.4 or more and are made of glass that consists essentially of SiO.sub.2 (60-90 weight-percent), alkali metal oxide (2-20 weight-percent), B.sub.2 O.sub.3 (1-30 weight-percent), sulfur (0.005 to 0.5 weight-percent), and other conventional glass-forming ingredients.
    Type: Grant
    Filed: February 25, 1982
    Date of Patent: July 5, 1983
    Assignee: Minnesota Mining and Manufacturing Company
    Inventor: Peter A. Howell