| 摘要 |
PROBLEM TO BE SOLVED: To provide an underground boring device capable of increasing, twice or more, a boring depth enabled to be bored with a single drill and reducing the number of joints of the drill so as to remarkably improve a boring operation. SOLUTION: A drill feeding device to feed a drill 2 and a drill rotating device 3 to rotate the upper end of the drill 2 are installed on a long frame 1, and a laterally pair of semi-cylindrical drill support guides 6a located at the middle position of the frame 1 are installed at the tip of a swing arm 6c. An opening and closing swing transmission arm 6e having an engaging groove 6f engaged with an opening and closing roller 3a of the drill rotating device 3 is installed pivotally on a pivot shaft 6d of the swing arm 6c.
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