| 摘要 |
An earth borer including a thin-walled tubular shaft (4) having smooth inner and outer surfaces, a shank (2) provided at one end of the tubular shaft (4), a drilling head (5) provided at another, opposite end of the tubular shaft, projecting radially beyond the tubular shaft (4), and having at least one cutter (6, 6a, 6b, 6c, 6d) extending, at least partially, radially inward and at least one internal groove (7, 7a, 7b) associated with the at least one cutter, and a releasable tubular connection member (8) for drivingly connecting the shank (2) with tubular shaft (4) for joint rotation with each other.
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