Patents by Inventor Tracy H. Calkins

Tracy H. Calkins 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: 3946982
    Abstract: Apparatus for finish casting of bifocal ophthalmic lenses from plastic material is described. No further surface grinding or polishing of the lens is required. The portion of the bifocal segment of the lens may be adjusted to any desired location relative to the optical center of the distance field of the lens. The apparatus comprises a power mold having a predetermined spherical or sphero-cylindrical surface, a bifocal mold having a predetermined optical curvature with a bifocal segment having a different optical curvature countersunk in the face thereof, and an annular gasket coupling the power and bifocal molds. The bifocal segment is adjusted relative to the optical center of the cast lens by use of a wedge member. An illustrative calculation to determine placement and thickness of the wedge for a given ophthalmic prescription is set forth.
    Type: Grant
    Filed: September 3, 1974
    Date of Patent: March 30, 1976
    Assignee: Textron, Inc.
    Inventors: Tracy H. Calkins, Frank E. Duckwall