Extension telephone system

Details Extension telephone system Extension telephone system

1976-07-21

1978-03-14

Claffy, Kathleen H.

H04M 172

Patent

active

040792129

ABSTRACT:
An extension telephone system in which a main equipment and each of a plurality of key telephone sets are connected together through paired information conductors and paired control conductors. The key telephone system can perform various functions such as answering to an incoming call from a single central office line, holding of the single central office line, transferring the incoming call from the single central office line from one key telephone set to another key telephone set, keeping the central office line in secrecy, incoming call indication, line busy indication, line holding indication and individual paging with electronic sound or voice by variation and polarity reversal of a DC voltage applied between the paired control conductors by the main equipment and utilization of the information conductors for a central office line communication, internal communication and individual paging control.

REFERENCES:
patent: 3453396 (1969-07-01), Lacey et al.
patent: 3514544 (1970-05-01), Chambers, Jr.
patent: 3927278 (1975-12-01), Tsutsumi et al.
patent: 4024353 (1977-05-01), Hijikata

Affiliated with

Also associated with

Rating

Extension telephone system does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Extension telephone system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Extension telephone system will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2231535