FR780267A - Improvements to telephone devices - Google Patents

Improvements to telephone devices

Info

Publication number
FR780267A
FR780267A FR780267DA FR780267A FR 780267 A FR780267 A FR 780267A FR 780267D A FR780267D A FR 780267DA FR 780267 A FR780267 A FR 780267A
Authority
FR
France
Prior art keywords
telephone devices
telephone
devices
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
French (fr)
Inventor
Louis Paul Durand
Pier Carlo Ricchiardi
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 filed Critical
Application granted granted Critical
Publication of FR780267A publication Critical patent/FR780267A/en
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
    • H04M1/60—Substation equipment, e.g. for use by subscribers including speech amplifiers
    • H04M1/6033—Substation equipment, e.g. for use by subscribers including speech amplifiers for providing handsfree use or a loudspeaker mode in telephone sets
FR780267D 1934-01-09 1934-01-09 Improvements to telephone devices Expired FR780267A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR780267T 1934-01-09

Publications (1)

Publication Number Publication Date
FR780267A true FR780267A (en) 1935-04-23

Family

ID=9204023

Family Applications (1)

Application Number Title Priority Date Filing Date
FR780267D Expired FR780267A (en) 1934-01-09 1934-01-09 Improvements to telephone devices

Country Status (1)

Country Link
FR (1) FR780267A (en)

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