FR881670A - Perfectionnement aux serrures téléphoniques - Google Patents

Perfectionnement aux serrures téléphoniques

Info

Publication number
FR881670A
FR881670A FR881670DA FR881670A FR 881670 A FR881670 A FR 881670A FR 881670D A FR881670D A FR 881670DA FR 881670 A FR881670 A FR 881670A
Authority
FR
France
Prior art keywords
improvement
locks
telephone
telephone locks
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.)
Expired
Application number
Other languages
English (en)
French (fr)
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.)
Mefina SA
Original Assignee
Mefina SA
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 Mefina SA filed Critical Mefina SA
Application granted granted Critical
Publication of FR881670A publication Critical patent/FR881670A/fr
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M1/00—Substation equipment, e.g. for use by subscribers
    • H04M1/66—Substation equipment, e.g. for use by subscribers with means for preventing unauthorised or fraudulent calling
    • H04M1/667—Preventing unauthorised calls from a telephone set
    • H04M1/67—Preventing unauthorised calls from a telephone set by electronic means

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Security & Cryptography (AREA)
  • Signal Processing (AREA)
FR881670D 1939-12-12 1940-12-12 Perfectionnement aux serrures téléphoniques Expired FR881670A (fr)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
BE881670X 1939-12-12

Publications (1)

Publication Number Publication Date
FR881670A true FR881670A (fr) 1943-05-05

Family

ID=3883816

Family Applications (1)

Application Number Title Priority Date Filing Date
FR881670D Expired FR881670A (fr) 1939-12-12 1940-12-12 Perfectionnement aux serrures téléphoniques

Country Status (2)

Country Link
BE (1) BE437345A (enrdf_load_stackoverflow)
FR (1) FR881670A (enrdf_load_stackoverflow)

Also Published As

Publication number Publication date
BE437345A (enrdf_load_stackoverflow)

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