| 摘要 |
A core barrel having a hollow cutting ring is placed within a hollow drill and connected to a coupling which permits the core barrel to remain stationary while the bit rotates and also produces pressure to force the sharp edge of the cutting ring into the earth formation, the diameter of the cutting edge and inside of the cutting ring being slightly less than the internal diameter of the core barrel. A holder for a resilient sleeve, such as woven of nylon and is bunched onto the holder with the closed end of the sleeve across the open top of the holder, moves upwardly around the core as the core barrel moves downwardly and retains the core, particularly when from a soft formation or loose unconsolidated material, in the same relative position and shape as when cut. The inside diameter of the holder is intermediate that of the cutting ring and the core barrel. An adjustment means determines the axial spacing between the cutting edge of the core barrel cutting ring and the lower edge of the drill bit or teeth.
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