Patents by Inventor Martin A. Calvert

Martin A. Calvert 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: 3981066
    Abstract: Apparatus for inserting a relatively hard seal ring into a circular groove with a restricted opening, comprising an annular funneled chute formed by inner and outer annular members and an intermediate push ring on which they are slideably mounted. The outer member may be retracted against springs whereby the seal ring may be placed over a conical surface of the inner ring.
    Type: Grant
    Filed: November 11, 1974
    Date of Patent: September 21, 1976
    Assignee: Grove Valve and Regulator Company
    Inventor: Martin A. Calvert