Lynn R Bosen

US Patent:

41350634, Jan 16, 1979

Filed:

Aug 12, 1977

Appl. No.:

5/824078

Inventors:

Lynn R. Bosen - Costa Mesa CA

Assignee:

San/Bar Corporation - Santa Ana CA

International Classification:

H04M 900

US Classification:

179 99

Abstract:

An intercom system for a key telephone installation which can be expanded and contracted to service a diverse number of subscriber units. The intercom system is expandable on a modular basis of eight subscriber units. The preferred embodiment can service up to forty-eight subscriber units. The intercom hardware includes a single supervision module, at least one signalling module, and one or more station modules. The intercom system provides up to six independent communication links for a forty-eight unit system. The system also provides such features as dial tone, ring-back tone, busy signal, interrupted ringing, and independent ringing. These features are provided by a hardware organization that is both expandable and comparatively inexpensive.