TREA

the subordinate centre permitting interconnection of subscribers connected thereto

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Industry

  • CPC
  • H04Q5/20
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Parent Industries

HELECTRICITY H04Electric communication H04QSELECTING H04Q5/00Selecting arrangements wherein two or more subscriber stations are connected by the same line to the exchange

Current Industry

H04Q5/20the subordinate centre permitting interconnection of subscribers connected thereto
Industries

Patents Grantslast 30 patents

  • Information Patent Grant

    Exclusion system for a key telephone system
    • Patent number 4,158,111
    • Issue date Jun 12, 1979
    • International Telephone & Telegraph Corp.
    • Bruce R. Saxon
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    3173128
    • Patent number 3,173,128
    • Issue date Mar 9, 1965
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    2850579
    • Patent number 2,850,579
    • Issue date Sep 2, 1958
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    2236797
    • Patent number 2,236,797
    • Issue date Apr 1, 1941
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    2201358
    • Patent number 2,201,358
    • Issue date May 21, 1940
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    2183839
    • Patent number 2,183,839
    • Issue date Dec 19, 1939
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    1942404
    • Patent number 1,942,404
    • Issue date Jan 9, 1934
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    1930921
    • Patent number 1,930,921
    • Issue date Oct 17, 1933
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    1896315
    • Patent number 1,896,315
    • Issue date Feb 7, 1933
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE
  • Information Patent Grant

    1783295
    • Patent number 1,783,295
    • Issue date Dec 2, 1930
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE