Patents by Inventor John A. Ritchie

John A. Ritchie 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).

  • Publication number: 20030053493
    Abstract: An architecture for providing high-speed access over frequency-division multiplexed (FDM) channels allows transmission of ethernet frames and/or other data across a cable transmission network or other form of FDM transport. The architecture involves downstream and upstream FDM multiplexing techniques to allow contemporaneous, parallel communications across a plurality of frequency channels. Also, the modulation indices of various upstream frequency channels may be different, but a plurality of upstream channels may be used to carry a single data flow generally in parallel. The upstream data flow is fragmented into blocks and formed into superframes to allow transmission over at least one upstream frequency channel. When a plurality of upstream frequency channels are utilized, the superframes facilitate the possibility of having different modulation indices on the plurality of frequency channels.
    Type: Application
    Filed: September 17, 2002
    Publication date: March 20, 2003
    Inventors: Joseph Graham Mobley, Jiening Ao, John A. Ritchie, Donald C. Sorenson, Lamar E. West
  • Patent number: 4590709
    Abstract: A support for a vertically hinged door including a bracket affixed to the lowermost free corner of the door and a pivotable support leg attached to the bracket for automatic movement between an extended support position and a horizontal stored position is disclosed. The support is provided with a stop and automatic latch for retaining the support leg in the support position.
    Type: Grant
    Filed: September 24, 1984
    Date of Patent: May 27, 1986
    Assignee: Cooper Industries, Inc.
    Inventors: Ilya Katsman, John A. Ritchie, Mark Burmenko, Vladimir Zaltsman
  • Patent number: 4467266
    Abstract: A battery charging system having a charger control circuit which monitors one cell of a battery bank and controls the operation of a charging current source in accordance with the terminal voltage of the monitored cell. The charger control circuit includes an overcharge sensing circuit and a shorted cell sensing circuit, each being capable of triggering a separate output driver to interrupt current flow from the charging current source to the battery bank. The overcharge sensing circuit employs a time delay network to avoid nuisance charger system interruptions. The shorted cell sensing circuit also employs a time delay network to allow charging of heavily discharged or zero voltage batteries.
    Type: Grant
    Filed: March 29, 1982
    Date of Patent: August 21, 1984
    Assignee: McGraw-Edison Company
    Inventor: John A. Ritchie