Patent assignee · US · COMPANY

Tone Commanders Systems, Inc.

7Patents
0Active
7Granted
23Portfolio score

Filing activity: Aug 6, 1976 → Aug 28, 1979

Most-cited patents

PatentTitleAreaCited byStatus
US4188511A Multi-link telephone intercom system Electricity 15 Expired
US4258232A Line hold circuits Electricity 11 Expired
US4086441A Message-waiting and do-not-disturb communications system Electricity 8 Expired
US4292475A Expandable link telephone intercom system Electricity 7 Expired
US4158110A Tone selective key telephone intercom system including digital tone detector Electricity 6 Expired
US4086444A Dial pulse key telephone intercom system Electricity 3 Expired
USD245871S Telephone communications module General 2 Expired

Source: USPTO / EPO open patent data. Counts and citation impact are objective bibliographic measures.