Patents by Inventor William D. Appel

William D. Appel 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).

  • Patent number: 5638287
    Abstract: Packaged signal routing circuits (e.g. on printed circuit cards or boards), route pulse signals with very short rise times from a lossy driver to multiple devices. In these routing circuits, a complex network of conductors branches from a common junction adjacent the driver output into multiple (in the disclosed embodiment, three) conduction paths of unequal length. In accordance with the invention, the internal impedance of the driver is matched to the aggregate charateristic impedance of the branch paths, and a lossless compensating circuit is attached to a shortest branch path. The compensating circuit is designed to transfer signal reflections of predetermined form to the branching junction at the driver via the shortest branch. Without the compensating circuit, reflections presented to the branching junction from the shortest branch are dissimilar to reflections presented to that junction from other branch paths.
    Type: Grant
    Filed: August 5, 1996
    Date of Patent: June 10, 1997
    Assignee: International Business Machines Corporation
    Inventor: William D. Appel
  • Patent number: 5544047
    Abstract: Packaged signal muting circuits (e.g. on primed circuit cards or boards), route pulse signals with very short rise times from a lossy driver to multiple devices. In these routing circuits, a complex network of conductors branches from a common junction adjacent the driver output into multiple (in the disclosed embodiment, three) conduction paths of unequal length. In accordance with the invention, the internal impedance of the driver is matched to the aggregate characteristic impedance of the branch paths, and a loss less compensating circuit is attached to a shortest branch path. The compensating circuit is designed to transfer signal reflections of predetermined form to the branching junction at the driver via the shortest branch.
    Type: Grant
    Filed: December 29, 1993
    Date of Patent: August 6, 1996
    Assignee: International Business Machines Corporation
    Inventor: William D. Appel
  • Patent number: 5074072
    Abstract: Fish bite signaling apparatus having a base shaped to cover an ice hole and including a hinged vertical handle which supports a fish line containing reel. A spring biased signaling flap projects from the base, magnetically interconnects with a number of magnets mounted to the reel and cooperates with separate visual and audio annunciation means. Line tensioning means and accessory support means are also provided.
    Type: Grant
    Filed: April 1, 1991
    Date of Patent: December 24, 1991
    Inventors: Richard R. Serocki, William D. Appel