Patents by Inventor Marilyn Richards

Marilyn Richards 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).

  • Prestressed plastic foam structural member
    Patent number: 4903446
    Abstract: A lightweight structural member made of prestressed plastic foam is provided, the prestress provided by a plurality of tendons disposed within the foam to which tensile forces are applied during mold casting of the structural member, the tendons being retained in tension by bonding between the tendons and the foam, or by way of anchors which are spaced along the tendons to retain the tendons in immobile condition, one or more skin layers also being optionally provided. A method for producing a lightweight structural member of prestressed plastic foam is also provided.
    Type: Grant
    Filed: April 26, 1988
    Date of Patent: February 27, 1990
    Assignee: Wesley Staples
    Inventors: Jack Richards, Marilyn Richards