| 摘要 |
A portable drilling mast structure comprising a lower drilling mast having a lower end pivotally coupled to a base. A hinge is coupled to an upper end of the lower drilling mast and a lower end of an upper drilling mast. The drilling mast structure has a first position wherein the lower drilling mast is parallel to the base and the upper drilling mast is disposed between the lower drilling mast and the base. The drilling mast structure has a second position wherein the lower drilling mast is perpendicular to the base and the upper drilling mast is aligned with the lower drilling mast.
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