| 摘要 |
A drill bit (10) for drilling geophysical exploratory holes using a non-rotating dill approach is disclosed. The bit (10) comprises a tubular body (12) threaded at one end for engagement with a pipe stem. The elements (16a-b) of a divided conical tip (14) are hinged to a second end (20) of the bit body (12). The wall thickness of the bit body (12) gradually increases from the first end (18) to the second end (20) to create, when the divided elements (16a-b) of the tip are closed, a generally diamond-shaped cross section facilitating burrowing when forced in to the soil. An O-ring (36) installed in a groove (34) about the outer circumference of the tip (14) biases divided elements (16a-b) closed until a selected tool is loaded through the interior of the bit body (12), whereupon the divided elements (16a-b) are forced to rotate radially outward. The bit (10) can then be raised and removed from the borehole as desired.
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