FR637230A - Improvements to telephone systems - Google Patents

Improvements to telephone systems

Info

Publication number
FR637230A
FR637230A FR637230DA FR637230A FR 637230 A FR637230 A FR 637230A FR 637230D A FR637230D A FR 637230DA FR 637230 A FR637230 A FR 637230A
Authority
FR
France
Prior art keywords
telephone systems
telephone
systems
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)
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.)
Associated Telephon & Telegrap
Original Assignee
Associated Telephon & Telegrap
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 Associated Telephon & Telegrap filed Critical Associated Telephon & Telegrap
Application granted granted Critical
Publication of FR637230A publication Critical patent/FR637230A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M3/00—Automatic or semi-automatic exchanges
    • H04M3/60—Semi-automatic systems, i.e. in which the numerical selection of the outgoing line is under the control of an operator
    • H04M3/62—Keyboard equipment

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
FR637230D 1926-10-23 1927-07-08 Improvements to telephone systems Expired FR637230A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US637230TA 1926-10-23 1926-10-23

Publications (1)

Publication Number Publication Date
FR637230A true FR637230A (en) 1928-04-25

Family

ID=1542612

Family Applications (1)

Application Number Title Priority Date Filing Date
FR637230D Expired FR637230A (en) 1926-10-23 1927-07-08 Improvements to telephone systems

Country Status (1)

Country Link
FR (1) FR637230A (en)

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