Device for adding intercom functions to a phone system
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United States of America Patent
Stats
-
Sep 6, 1988
Grant Date -
N/A
app pub date -
May 4, 1987
filing date -
May 4, 1987
priority date (Note) -
Expired
status (Latency Note)
Importance
Abstract
A device for adding intercom functions to a residential or small business phone system uses existing telephone equipment and wiring. The device attaches to the incoming telephone line to switch telephone calls and generate user coded ringing signals. The invention allows the user to simultaneously use existing telephone equipment as an intercom system and for normal outside telephone use.
First Claim
Family
International Classification(s)
Cited Art Landscape
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