GB191216241A - Improvements in or relating to Telephones. - Google Patents

Improvements in or relating to Telephones.

Info

Publication number
GB191216241A
GB191216241A GB191216241DA GB191216241A GB 191216241 A GB191216241 A GB 191216241A GB 191216241D A GB191216241D A GB 191216241DA GB 191216241 A GB191216241 A GB 191216241A
Authority
GB
United Kingdom
Prior art keywords
telephones
relating
ramdohr
directcall
nameplate
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
Inventor
Eugen Ramdohr
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.)
Individual
Original Assignee
Individual
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 Individual filed Critical Individual
Application granted granted Critical
Publication of GB191216241A publication Critical patent/GB191216241A/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
    • H04M1/02—Constructional features of telephone sets
    • H04M1/0291—Door telephones

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Telephone Set Structure (AREA)

Abstract

16,241. Ramdohr, E. July 11. Telephones, mounting and supporting; directcall systems.-In apparatus for facilitating conversation between a person at the door of a room or house and another within, a loudspeaking telephone receiver t<1> and transmitter m<1> are concealed behind the perforated nameplate, letter box, or the like n. The battery b supplies current through the receivers and transmitters t<1>, m<2> and m<1>, t<2>, with a common return through the lead i. The switch u closes both circuits when the hand-set h is in use. The circuit of the bell W is independent.
GB191216241D 1912-07-11 1912-07-11 Improvements in or relating to Telephones. Expired GB191216241A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB191216241T 1912-07-11

Publications (1)

Publication Number Publication Date
GB191216241A true GB191216241A (en) 1912-12-19

Family

ID=32368703

Family Applications (1)

Application Number Title Priority Date Filing Date
GB191216241D Expired GB191216241A (en) 1912-07-11 1912-07-11 Improvements in or relating to Telephones.

Country Status (2)

Country Link
FR (1) FR445939A (en)
GB (1) GB191216241A (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2552154A1 (en) * 1983-09-21 1985-03-22 Nivet Christian Device for communicating from the inside of an apartment to the outside without having to open its access

Also Published As

Publication number Publication date
FR445939A (en) 1912-11-22

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