TREA

with screw, worm, or the like, not self-locking but normally prevented from rotation by friction members which slip upon excessive pressure

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Industry

  • CPC
  • E21D15/26
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Parent Industries

EFIXED CONSTRUCTIONS E21Mining E21DSHAFTS TUNNELS GALLERIES LARGE UNDERGROUND CHAMBERS E21D15/00Props Chocks

Current Industry

E21D15/26with screw, worm, or the like, not self-locking but normally prevented from rotation by friction members which slip upon excessive pressure
Industries

Patents Grantslast 30 patents

  • Information Patent Grant

    3706441
    • Patent number 3,706,441
    • Issue date Dec 19, 1972
    • E21 - EARTH DRILLING MINING
  • Information Patent Grant

    2771264
    • Patent number 2,771,264
    • Issue date Nov 20, 1956
    • E21 - EARTH DRILLING MINING
  • Information Patent Grant

    2747829
    • Patent number 2,747,829
    • Issue date May 29, 1956
    • E21 - EARTH DRILLING MINING
  • Information Patent Grant

    1795548
    • Patent number 1,795,548
    • Issue date Mar 10, 1931
    • B66 - HOISTING LIFTING HAULING