| 摘要 |
PURPOSE: A propulsion guide apparatus of a steel-pipe roof structure is provided to guide a drilling bit propelling the steel-pipe roof structure to advance in the specified direction. CONSTITUTION: A propulsion guide apparatus(10) of a steel-pipe roof structure, in which a rear propelling steel pipe(3) is installed in a front propelling steel pipe(1) with a longitudinal cut portion, increases the support area to the front propelling steel pipe and therefore propels the rear propelling steel pipe along the front propelling steel pipe without deviation. The guide apparatus is in contact with the interior of the front propelling steel pipe and keeps a drilling bit(2) from deviating the propulsion route of the front propelling steel pipe.
|
