PURPOSE: To decrease frictional losses by rotating or longitudinally vibrating central hammers provided at the end of the center of a pipe which does not rotate, and crushing the natural ground through the longitudinal movements of round hammers provided therearound.
CONSTITUTION: Central hammers 2, 2... which are rotated and vibrated by a longitudinal vibrating device 3 and a rotating device 4 are provided at the end of a pipe 1. A plurality of round hammers 5, 5... which are vibrated longitudinally by the longitudinal vibrating device 6 are arranged on the outer periphery of the hammer 2 or the like and an air ejecting hole 7 is provided in the center. The pipe 1 is inserted into the natural ground, and as the hammer 2 or the like is rotated and vibrated, the hammer 5 or the like is longitudinally vibrated to crush the natural ground while compressed air is ejected from the hole 7 and air around the hammer 2 is sucked to convey soil. Thus, since the pipe 1 is not rotated, frictional losses can be eliminated.
WO/1998/045733 | NEAR FIELD ELECTROMAGNETIC PROXIMITY DETERMINATION |
WO/2018/212776 | ROTARY STEERABLE DRILLING - PUSH-THE-POINT-THE-BIT |
WO/2015/012848 | EXPANDABLE BULLNOSE ASSEMBLY FOR USE WITH A WELLBORE DEFLECTOR |
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