JPS5259506A - Interrupt sound sending system - Google Patents

Interrupt sound sending system

Info

Publication number
JPS5259506A
JPS5259506A JP13506775A JP13506775A JPS5259506A JP S5259506 A JPS5259506 A JP S5259506A JP 13506775 A JP13506775 A JP 13506775A JP 13506775 A JP13506775 A JP 13506775A JP S5259506 A JPS5259506 A JP S5259506A
Authority
JP
Japan
Prior art keywords
sending system
sound sending
interrupt sound
extension
interruption
Prior art date
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
Application number
JP13506775A
Other languages
Japanese (ja)
Inventor
Kensho Tsujino
Goro Hanada
Michihiro Tanihara
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hitachi Ltd
Original Assignee
Hitachi Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Hitachi Ltd filed Critical Hitachi Ltd
Priority to JP13506775A priority Critical patent/JPS5259506A/en
Publication of JPS5259506A publication Critical patent/JPS5259506A/en
Pending legal-status Critical Current

Links

Abstract

PURPOSE: An extension control unit is installed at the latter stage of an extension telephone so that at the time of intentional interruption, only the extension line which is busy can detect the interruption, thereby making it possible to prevent secret from leaking and to achieve great functional improvement.
COPYRIGHT: (C)1977,JPO&Japio
JP13506775A 1975-11-12 1975-11-12 Interrupt sound sending system Pending JPS5259506A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP13506775A JPS5259506A (en) 1975-11-12 1975-11-12 Interrupt sound sending system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP13506775A JPS5259506A (en) 1975-11-12 1975-11-12 Interrupt sound sending system

Publications (1)

Publication Number Publication Date
JPS5259506A true JPS5259506A (en) 1977-05-17

Family

ID=15143085

Family Applications (1)

Application Number Title Priority Date Filing Date
JP13506775A Pending JPS5259506A (en) 1975-11-12 1975-11-12 Interrupt sound sending system

Country Status (1)

Country Link
JP (1) JPS5259506A (en)

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4728405U (en) * 1971-03-30 1972-12-01

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4728405U (en) * 1971-03-30 1972-12-01

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