Patents Assigned to Telecalc, Inc.
  • Telephone interconnect detection system
    Patent number: 4518825
    Abstract: A telephone interconnect detection system for selectively determining, during operation, interconnection of a plurality of trunk lines with a plurality of set lines interconnected by a pbx or the like.
    Type: Grant
    Filed: October 11, 1983
    Date of Patent: May 21, 1985
    Assignee: Telecalc, Inc.
    Inventors: Jesse R. Brinkerhoff, Richard S. Brinkerhoff