Patents by Inventor Keith E. Oxford

Keith E. Oxford 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 of automatically monitoring and regenerating an etchant
    Patent number: 4132585
    Abstract: The composition of etchant solution withdrawn from an etcher is monitored to diagnose a component deficiency. A light sensor is responsive to the color density of light rays passing through the etchant. A meter relay is responsive to the light sensor and if the color density of the etchant falls outside preset levels a pump is energized causing addition of a constituent component into the etchant. A second light sensor senses the color density of the light rays passing through the etchant after the addition of the constituent component. A second meter relay is responsive to the second light sensor. If no improvement of the etchant color is detected, the second meter relay causes the discontinuance of the constituent component addition and switches to the addition of another constituent component.
    Type: Grant
    Filed: April 4, 1977
    Date of Patent: January 2, 1979
    Inventor: Keith E. Oxford
  • Automatic etching system
    Patent number: 4060097
    Abstract: The composition of etchant solution withdrawn from an etcher is monitored to diagnose a component deficiency. A light sensor is responsive to the color density of light rays passing through the etchant. A meter relay is responsive to the light sensor and if the color density of the etchant falls outside preset levels a pump is energized causing addition of a constituent component into the etchant. A second light sensor senses the color density of the light rays passing through the etchant after the addition of the constituent component. A second meter relay is responsive to the second light sensor. If no improvement of the etchant color is detected, the second meter relay causes the discontinuance of the constituent component addition and switches to the addition of another constituent component.
    Type: Grant
    Filed: April 4, 1977
    Date of Patent: November 29, 1977
    Inventor: Keith E. Oxford