Patents by Inventor Michael T. Clitherow

Michael T. Clitherow 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).

  • Virtual calling card system
    Patent number: 5479494
    Abstract: A calling card subscriber is allowed to choose at least some of the digits of his or her calling card number to form a virtual card number. Associated with the virtual card number is a standardized card number i.e., a number conforming to the Bellcore calling card numbering plan. When the subscriber uses the virtual card number to make a calling card call, the virtual card number is mapped into the standardized number. The latter is then used by the telephone system for subsequent validation and billing.
    Type: Grant
    Filed: October 5, 1992
    Date of Patent: December 26, 1995
    Assignee: AT&T Corp.
    Inventor: Michael T. Clitherow