Hot-line device for telephone sets
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
Jan 31, 1989
Grant Date -
N/A
app pub date -
May 19, 1987
filing date -
May 19, 1987
priority date (Note) -
Expired
status (Latency Note)
Importance
Abstract
A hot-line device for telephone sets includes a logic AND gate circuit serving as a central unit with its output to be electrically connected to a control circuit through the keyboard of a telephone set, and its inputs respectively coupled with a hot-line triggering circuit, a dial-tone detection circuit and a ringing detection and delay circuit separately disposed in the telephone set for automatically effecting dialing operation during an emergency situation. Alternatively, the logic AND gate circuit can be replaced with a microprocessor for performing automatic dialing operation through a predetermined program.
First Claim
Family
International Classification(s)
Cited Art Landscape
Patent Citation Ranking
Advertisement
Advertisement
Advertisement
Recipient Email Address
Recipient Email Address
Comment
Recipient Email Address
Add to Portfolio(s)
To add this patent to one, or more, of your portfolios, simply click the add button.
This Patent is in these Portfolios:
Add to additional portfolios:
Last Refreshed On:
Changes done successfully