| 摘要 |
PROBLEM TO BE SOLVED: To press fit a casing without conducting a ground-removing work to discharge soil while rotatably pressing in the casing. SOLUTION: A plurality of cutting edges 2,2... are provided to the lower end face of the casing head 1 in a protruding condition. Viewing their inside and outside faces from the lower end face of the head, the cutting edges 2, 2... have the distal ends of the outside face extending on or toward a little more outward direction from the outer periphery of the head while the rear ends of the inside faces, which slant to the opposite direction to the rotational direction of the casing head 1, extending slightly toward inner direction from the inside margin of the lower end opening of the head. Furthermore, the cutting edges are formed in slant-pressing faces 3,3... which are almost perpendicular to the lower end face of the casing 1. Also, with the casing head having the lower end edges of the slant-pressing faces 3,3... formed on the cutting edges, the excavated soil is consolidated within the inner periphery of the casing A,A... COPYRIGHT: (C)2005,JPO&NCIPI
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