9 SOLID STATE ELECTRONIC DEVICE PROVIDING INTERCOMMUNICATION BETWEEN STATIONS ON CONVENTIONAL TELEPHONE KEY SYSTEMS, THE UNIT PROVIDING INDEPENDENT TALKING CURRENT AND DIAL TONE MULTIFREQUENCY SELECTIVE SIGNALLING
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Trademark Events
Jun 2, 1998
Expired Sec. 9
Oct 3, 1983
Registered - Sec. 8 (6-Yr) Accepted & Sec. 15 Ack.