| 摘要 |
Once a bore hole 11 has been formed, an auger 4 is withdrawn from the bore hole 11 after a scraper blade 22 has been fitted between two of its successive turns positioned above the excavated material 18. When the auger 4 is raised the scraper blade 22 has been made to slide up the length of the mast 1. Then, the machine 2 has moved the auger 4 to the side of the bore hole 11. The auger 4 is then made to rotate in the opposite direction from that for drilling into the ground. The blade 22, on the other hand, is prevented from turning around the axis of the auger 4. In this way the rotation of the auger causes the blade to move down the length of the mast and to clean the space between the turns on the auger. Used to simplify the cleaning device and to prevent excavated material from falling into the bore hole. <IMAGE>
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