JPS5099006A - - Google Patents
Info
- Publication number
- JPS5099006A JPS5099006A JP49148541A JP14854174A JPS5099006A JP S5099006 A JPS5099006 A JP S5099006A JP 49148541 A JP49148541 A JP 49148541A JP 14854174 A JP14854174 A JP 14854174A JP S5099006 A JPS5099006 A JP S5099006A
- Authority
- JP
- Japan
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M3/00—Automatic or semi-automatic exchanges
- H04M3/42—Systems providing special services or facilities to subscribers
- H04M3/56—Arrangements for connecting several subscribers to a common circuit, i.e. affording conference facilities
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M1/00—Substation equipment, e.g. for use by subscribers
- H04M1/68—Circuit arrangements for preventing eavesdropping
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Multimedia (AREA)
- Sub-Exchange Stations And Push- Button Telephones (AREA)
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US05/428,067 US4117274A (en) | 1973-12-26 | 1973-12-26 | Key telephone privacy circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS5099006A true JPS5099006A (ja) | 1975-08-06 |
Family
ID=23697416
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP49148541A Pending JPS5099006A (ja) | 1973-12-26 | 1974-12-26 |
Country Status (3)
| Country | Link |
|---|---|
| US (1) | US4117274A (ja) |
| JP (1) | JPS5099006A (ja) |
| CA (1) | CA1044389A (ja) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4158111A (en) * | 1978-01-13 | 1979-06-12 | International Telephone & Telegraph Corp. | Exclusion system for a key telephone system |
| CA1200036A (en) * | 1978-03-13 | 1986-01-28 | Guido Panizzon | Partyline subscriber interface circuit |
| JPS54162714U (ja) * | 1978-05-02 | 1979-11-14 | ||
| US4218590A (en) * | 1979-01-29 | 1980-08-19 | Crest Industries, Inc. | Key telephone system having automatic exclusion circuit for line privacy |
| US4266103A (en) * | 1979-07-26 | 1981-05-05 | Gte Automatic Electric Laboratories Inc. | Key telephone exclusion circuit |
| US4821319A (en) * | 1985-04-25 | 1989-04-11 | Alcatel Usa Corp. | Single line telephone communication system |
| AU692661B2 (en) * | 1995-02-09 | 1998-06-11 | Rpx Corporation | Key telephone system capable of simulation by button operations |
| US8879707B2 (en) * | 2005-01-14 | 2014-11-04 | Avaya Inc. | Private branch exchange that manages interactions between associated telecommunications terminals |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3299217A (en) * | 1963-10-31 | 1967-01-17 | Bell Telephone Labor Inc | Auxiliary interconnecting unit for multi-line subscriber telephone system |
| US3385935A (en) * | 1964-10-19 | 1968-05-28 | Bell Telephone Labor Inc | Key telephone system |
| US3499121A (en) * | 1966-03-03 | 1970-03-03 | Proctor & Associates Co | Communication system exclusion circuit |
| US3514544A (en) * | 1967-04-21 | 1970-05-26 | Charles W Chambers Jr | Party line privacy device |
| US3725601A (en) * | 1971-03-05 | 1973-04-03 | Bell Telephone Labor Inc | Direct station selection private intercom exchange system |
-
1973
- 1973-12-26 US US05/428,067 patent/US4117274A/en not_active Expired - Lifetime
-
1974
- 1974-11-07 CA CA213,263A patent/CA1044389A/en not_active Expired
- 1974-12-26 JP JP49148541A patent/JPS5099006A/ja active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| US4117274A (en) | 1978-09-26 |
| CA1044389A (en) | 1978-12-12 |