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GB522457A - Improvements in or relating to systems of simultaneous telephony on a number of lines - Google Patents

Improvements in or relating to systems of simultaneous telephony on a number of lines

Info

Publication number
GB522457A
GB522457A GB35900/38A GB3590038A GB522457A GB 522457 A GB522457 A GB 522457A GB 35900/38 A GB35900/38 A GB 35900/38A GB 3590038 A GB3590038 A GB 3590038A GB 522457 A GB522457 A GB 522457A
Authority
GB
United Kingdom
Prior art keywords
line
exchange
lines
substation
call
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
GB35900/38A
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
Priority to GB35900/38A priority Critical patent/GB522457A/en
Priority to US245793A priority patent/US2192540A/en
Priority to FR847727D priority patent/FR847727A/en
Publication of GB522457A publication Critical patent/GB522457A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M9/00—Arrangements for interconnection not involving centralised switching
    • H04M9/001—Two-way communication systems between a limited number of parties
    • 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

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Sub-Exchange Stations And Push- Button Telephones (AREA)
  • Interconnected Communication Systems, Intercoms, And Interphones (AREA)

Abstract

522,457. Exchange systems. CRETI, M. Dec. 8, 1938, No. 35900. [Class 40 (iv)] Two or more exchange lines I, II share a common substation set to which they are connected by relays R', R" which are energized by ringing current and then lock up to the exchange battery. Assuming that a call has been set up in the usual way over one line, the subscriber can hold that connection by bridging the line by a resistance. such as W<SP>1</SP>, release the corresponding relay R' by the key A<SP>1</SP>, bridge the relay R" across the other line without the condenser K" to call the exchange and connect that substation set to that line and then estab- , lish any wanted connection, e.g., by dialling at D. The relay R' can then be re-operated to enable the three parties to converse. Local extension stations can be brought in by means of keys 6 .. 8 which complete line circuits to and so operate buzzers at the wanted stations. The called extension parties simply' disconnect the buzzers at 50 ... 52. The extension stations can call the substation by means of keys 11 ... 13 and can be connected to the exchange lines. Lamps L', L" indicate which lines are in use. By means of a switch S the substation can make use of an ordinary handset or of sensitive microphones M and amplifier and loud-speaker AM, AL, the amplifier being switched on by the relays R<SP>1</SP>, R".
GB35900/38A 1938-12-02 1938-12-08 Improvements in or relating to systems of simultaneous telephony on a number of lines Expired GB522457A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
GB35900/38A GB522457A (en) 1938-12-02 1938-12-08 Improvements in or relating to systems of simultaneous telephony on a number of lines
US245793A US2192540A (en) 1938-12-02 1938-12-14 Telephone system
FR847727D FR847727A (en) 1938-12-02 1938-12-19 Enhancements to simultaneous multi-line telephony systems

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
IT2192540X 1938-12-02
GB35900/38A GB522457A (en) 1938-12-02 1938-12-08 Improvements in or relating to systems of simultaneous telephony on a number of lines
FR847727X 1938-12-19

Publications (1)

Publication Number Publication Date
GB522457A true GB522457A (en) 1940-06-18

Family

ID=32071313

Family Applications (1)

Application Number Title Priority Date Filing Date
GB35900/38A Expired GB522457A (en) 1938-12-02 1938-12-08 Improvements in or relating to systems of simultaneous telephony on a number of lines

Country Status (3)

Country Link
US (1) US2192540A (en)
FR (1) FR847727A (en)
GB (1) GB522457A (en)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH258989A (en) * 1942-12-04 1948-12-31 Autophon Ag Arrangement for switching the speech direction in intercom systems for noisy traffic.
US2449344A (en) * 1942-12-10 1948-09-14 Autophon Ag Device for conference calls in subscribers' devices for loud and faintly audible traffic
CH258725A (en) * 1942-12-21 1948-12-15 Autophon Ag Remote switchable self-connection telephone for noisy traffic.
US2477275A (en) * 1944-01-15 1949-07-26 Firm Autophon Ag Voice-controlled two-way communication system
CH250532A (en) * 1944-10-21 1947-08-31 Autophon Ag Arrangement in an intercom for noisy traffic.
US2427850A (en) * 1945-03-17 1947-09-23 Rca Corp Switching method and system
DE3145756A1 (en) * 1981-11-19 1983-05-26 Wabco Westinghouse Fahrzeugbremsen GmbH, 3000 Hannover Diaphragm cylinder, especially for hydraulically operated vehicle brake systems

Also Published As

Publication number Publication date
US2192540A (en) 1940-03-05
FR847727A (en) 1939-10-16

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