without essential shifting devices

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  • CPC
  • E21D23/0047
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Patents Grantslast 30 patents

  • Information Patent Grant

    Equipment system for no-roadway no-coal-pillar retained roadway min...

    • Patent number 11,008,860
    • Issue date May 18, 2021
    • Manchao HE
    • Manchao He
    • E21 - EARTH DRILLING MINING
  • Information Patent Grant

    3885396

    • Patent number 3,885,396
    • Issue date May 27, 1975
    • E21 - EARTH DRILLING MINING
  • Information Patent Grant

    3626700

    • Patent number 3,626,700
    • Issue date Dec 14, 1971
    • E21 - EARTH DRILLING MINING
  • Information Patent Grant

    3488966

    • Patent number 3,488,966
    • Issue date Jan 13, 1970
    • E21 - EARTH DRILLING MINING
  • Information Patent Grant

    3474628

    • Patent number 3,474,628
    • Issue date Oct 28, 1969
    • E21 - EARTH DRILLING MINING
  • Information Patent Grant

    3466875

    • Patent number 3,466,875
    • Issue date Sep 16, 1969
    • E21 - EARTH DRILLING MINING
  • Information Patent Grant

    3431737

    • Patent number 3,431,737
    • Issue date Mar 11, 1969
    • E21 - EARTH DRILLING MINING
  • Information Patent Grant

    3425229

    • Patent number 3,425,229
    • Issue date Feb 4, 1969
    • E21 - EARTH DRILLING MINING
  • Information Patent Grant

    3399927

    • Patent number 3,399,927
    • Issue date Sep 3, 1968
    • E21 - EARTH DRILLING MINING
  • Information Patent Grant

    3397543

    • Patent number 3,397,543
    • Issue date Aug 20, 1968
    • E21 - EARTH DRILLING MINING
  • Information Patent Grant

    3392533

    • Patent number 3,392,533
    • Issue date Jul 16, 1968
    • E21 - EARTH DRILLING MINING
  • Information Patent Grant

    3383866

    • Patent number 3,383,866
    • Issue date May 21, 1968
    • E21 - EARTH DRILLING MINING
  • Information Patent Grant

    3381480

    • Patent number 3,381,480
    • Issue date May 7, 1968
    • E21 - EARTH DRILLING MINING
  • Information Patent Grant

    3371901

    • Patent number 3,371,901
    • Issue date Mar 5, 1968
    • E21 - EARTH DRILLING MINING
  • Information Patent Grant

    3365893

    • Patent number 3,365,893
    • Issue date Jan 30, 1968
    • E21 - EARTH DRILLING MINING
  • Information Patent Grant

    3355213

    • Patent number 3,355,213
    • Issue date Nov 28, 1967
    • E21 - EARTH DRILLING MINING
  • Information Patent Grant

    3313114

    • Patent number 3,313,114
    • Issue date Apr 11, 1967
    • E21 - EARTH DRILLING MINING
  • Information Patent Grant

    3289997

    • Patent number 3,289,997
    • Issue date Dec 6, 1966
    • E21 - EARTH DRILLING MINING
  • Information Patent Grant

    3240022

    • Patent number 3,240,022
    • Issue date Mar 15, 1966
    • E21 - EARTH DRILLING MINING
  • Information Patent Grant

    3201943

    • Patent number 3,201,943
    • Issue date Aug 24, 1965
    • E21 - EARTH DRILLING MINING
  • Information Patent Grant

    3197966

    • Patent number 3,197,966
    • Issue date Aug 3, 1965
    • E21 - EARTH DRILLING MINING
  • Information Patent Grant

    3192722

    • Patent number 3,192,722
    • Issue date Jul 6, 1965
    • E21 - EARTH DRILLING MINING
  • Information Patent Grant

    3186178

    • Patent number 3,186,178
    • Issue date Jun 1, 1965
    • E21 - EARTH DRILLING MINING
  • Information Patent Grant

    1946034

    • Patent number 1,946,034
    • Issue date Feb 6, 1934
    • E21 - EARTH DRILLING MINING
  • Information Patent Grant

    1594475

    • Patent number 1,594,475
    • Issue date Aug 3, 1926
    • E21 - EARTH DRILLING MINING

Patents Applicationslast 30 patents