Patents by Inventor John H. Mitchell

John H. Mitchell 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).

  • Protection screen for condenser unit
    Patent number: 6138993
    Abstract: A protection screen for a condenser unit of an air conditioning or heat pump system utilizes a plurality of screen panels to form a protective enclosure about the periphery of the condenser unit. The protection screen is self-supporting and is spaced a sufficient distance from the condenser unit to provide an adequate air gap. The protection screen prevents ingress of clogging particulate matter into the heat exchanger portion of the condenser unit.
    Type: Grant
    Filed: September 4, 1998
    Date of Patent: October 31, 2000
    Inventors: James E. Mitchell, Jr., John H. Mitchell, Norman E. Logan
  • Programmable optical correlator
    Patent number: 5233554
    Abstract: An optical correlation system employing the degenerate four wave mixing uses cross-polarized pump and probe beams to prevent the writing of a volume transmission phase hologram in a photorefractive crystal having an applied electric field parallel to the optic axis of the system, so that system response does not depend on the time required to write or erase such a transmission hologram.
    Type: Grant
    Filed: September 10, 1990
    Date of Patent: August 3, 1993
    Assignee: United Technologies Corporation
    Inventors: William F. Conley, John H. Mitchell
  • Decolorization of polyalkylene polyamines
    Patent number: 5227528
    Abstract: A process for decolorizing polyalkylene polyamines, which comprises contacting one or more polyalkylene polyamines having an average molecular weight of greater than about 200 and less than about 1000 with carbon at a temperature greater than or equal to about 100.degree. C. and less than or equal to about 300.degree. C. under conditions effective to reduce the color rating of the one or more polyalkylene polyamines.
    Type: Grant
    Filed: April 30, 1992
    Date of Patent: July 13, 1993
    Assignee: The Dow Chemical Company
    Inventors: Stephen J. Webster, John H. Mitchell
  • Optical system for wavefront compensation
    Patent number: 4996412
    Abstract: A laser wavefront control system employs a common optical path and common high-power deformable mirror to optically compensate an incoming beacon or retroreflected return beam and a laser sample beam, in which the phase conjugate of the laser sample beam is impressed on a low-power deformable mirror. This control system drives the high-power deformable mirror, and has as its input the phase modulation required for compensation of optically sensed wavefront phase errors.
    Type: Grant
    Filed: December 7, 1989
    Date of Patent: February 26, 1991
    Assignee: United Technologies Corporation
    Inventors: David Anafi, John H. Mitchell, Harold B. Schall