with equipment for cleaning the slit

Industry

  • CPC
  • E21C25/50
This industry / category may be too specific. Please go to a parent level for more data

Patents Grantslast 30 patents

  • Information Patent Grant

    2454446

    • Patent number 2,454,446
    • Issue date Nov 23, 1948
    • E21 - EARTH DRILLING MINING
  • Information Patent Grant

    2268260

    • Patent number 2,268,260
    • Issue date Dec 30, 1941
    • E21 - EARTH DRILLING MINING
  • Information Patent Grant

    2125296

    • Patent number 2,125,296
    • Issue date Aug 2, 1938
    • E21 - EARTH DRILLING MINING
  • Information Patent Grant

    1998876

    • Patent number 1,998,876
    • Issue date Apr 23, 1935
    • E21 - EARTH DRILLING MINING
  • Information Patent Grant

    1997093

    • Patent number 1,997,093
    • Issue date Apr 9, 1935
    • E21 - EARTH DRILLING MINING
  • Information Patent Grant

    1846574

    • Patent number 1,846,574
    • Issue date Feb 23, 1932
    • E21 - EARTH DRILLING MINING
  • Information Patent Grant

    1662800

    • Patent number 1,662,800
    • Issue date Mar 13, 1928
    • E21 - EARTH DRILLING MINING
  • Information Patent Grant

    1414586

    • Patent number 1,414,586
    • Issue date May 2, 1922
    • E21 - EARTH DRILLING MINING