Patents by Inventor Marshal L. Whitehurst

Marshal L. Whitehurst 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).

  • Method for the manufacture of capacitive electronic discs
    Patent number: 4470940
    Abstract: Release properties of stampers used in the manufacture of capacitive electronic discs are improved by passivating the molding surface of the stamper with an oxidizing agent.
    Type: Grant
    Filed: September 5, 1980
    Date of Patent: September 11, 1984
    Assignee: RCA Corporation
    Inventor: Marshal L. Whitehurst
  • Method for the manufacture of recording substrates for capacitance electronic discs
    Patent number: 4316778
    Abstract: Amphoteric fluorocarbon surfactants when added to acid copper plating baths which contain brighteners will substantially reduce or eliminate occluded hydrogen in the deposited copper without adversely affecting the properties of the copper and in particular the brightness of the copper.
    Type: Grant
    Filed: September 24, 1980
    Date of Patent: February 23, 1982
    Assignee: RCA Corporation
    Inventor: Marshal L. Whitehurst
  • Method for the manufacture of capacitive electronic discs
    Patent number: 4305791
    Abstract: A method for passivating the surface of a recorded metal substrate in which the substrate is immersed for 5-30 minutes in a 35.degree. C.-85.degree. C. aqueous bath containing from about 5 to 30 g/l of an alkaline cleaner and from about 2.5 to 20 g/l of sodium dichromate, potassium dichromate, sodium permanganate, potassium permanganate, or mixtures thereof.
    Type: Grant
    Filed: September 5, 1980
    Date of Patent: December 15, 1981
    Assignee: RCA Corporation
    Inventor: Marshal L. Whitehurst
  • Shield for plating substrate
    Patent number: 4259166
    Abstract: In an apparatus for plating the cylindrical flat surface of a metal substrate which is seated in a recess in a substrate case, a shield is mounted on the case around the edge of the surface of the substrate. The shield has an opening therethrough of a diameter adjacent the substrate substantially equal to the diameter of the surface of the substrate, and at the top surface thereof smaller than the diameter of the substrate so as to extend over the substrate. The portion of the opening adjacent the substrate is beveled radially inwardly at an angle of between 45 degrees and 60 degrees.
    Type: Grant
    Filed: March 31, 1980
    Date of Patent: March 31, 1981
    Assignee: RCA Corporation
    Inventor: Marshal L. Whitehurst