Patents by Inventor Alan S. Markham

Alan S. Markham 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).

  • Methods of and systems for controlling the expansion of cellular plastic insulation in the manufacture of insulated conductors
    Patent number: 4359436
    Abstract: A conductive element (22) is preheated by a preheat power supply (34) to an initial temperature which is a function of line speed. The preheated conductive element (22) is advanced through an extruder (32) whereat a cellular insulation layer (24) and a solid plastic insulation layer (26) are extruded thereabout to form an insulated conductor (20). The insulated conductor (20) is advanced through an air gap (38) whereat the cellular insulation layer 24 expands about the conductive element (22). The insulated conductor (20) is then quenched at a point to stop the expansion of the cellular insulation layer by passing the insulated conductor into a cooling bath (40).A capacitance monitor (50) measures the coaxial capacitance of the insulated conductor (20) and develops an error signal.
    Type: Grant
    Filed: April 29, 1981
    Date of Patent: November 16, 1982
    Assignee: Western Electric Company, Inc.
    Inventors: Joseph G. Henderson, Alan S. Markham, Richard D. Neumyer