Patents by Inventor Robert C. Ingraham

Robert C. Ingraham 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).

  • Lamp envelope having a luminescent material on the interior surface thereof, method of applying said material, and material to be applied
    Patent number: 4914346
    Abstract: Heavy weights of luminescent material; e.g., from 0.0087 to 0.010 g/cm.sup.2, can be applied and adhered to the interior surface of lamp envelopes by mixing with the material up to 20% by weight boric acid. The material and boric acid are applied by electrostatic deposition and the envelope containing the material is then heated to a temperature of at least 300.degree. C. to convert the boric acid to boron anhydride. The envelope is subsequently cooled and employed with a light source capsule to form a lamp.
    Type: Grant
    Filed: December 11, 1987
    Date of Patent: April 3, 1990
    Assignee: GTE Products Corporation
    Inventor: Robert C. Ingraham