Patents by Inventor Donald C. Heckman

Donald C. Heckman 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: 5187740
    Abstract: The invention is an adaptive method and apparatus for telephone call reorigination (i.e., the placement of successive calls without extended re-dialing). It allows shorter, uniform DTMF reorigination requests or commands to be recognized and responded to during certain stages of a call while preserving a filtering effect to avoid "talk off" reorigination during the call's talking stage. In the initial stage of a call, prior to verifying the caller's authority to place the call, a first mode of request detection, responsive to short duration tones is used. During call setup and prior to answer by a called party, a second mode of detection is used which is also responsive to short duration tones. In the talking stage, another mode of detection is used to avoid inadvertent reoriginations due to spurious tones. In one aspect, a dial tone is automatically returned to the caller upon called party disconnect.
    Type: Grant
    Filed: October 1, 1991
    Date of Patent: February 16, 1993
    Assignee: MCI Communications Corporation
    Inventors: Joe T. Swaim, Donald C. Heckman, Kenneth J. O'Grady, Guido M. Eastep