| 摘要 |
<p>A portable drilling mast structure (200) has a lower drilling mast (202) having a lower end pivotally coupled to a base (110). A hinge (206) is coupled to an upper end of the lower drilling mast (202) and a lower end of an upper drilling mast (204). The drilling mast structure (200) has a first position in which the lower drilling mast (202) is parallel to the base (110) and the upper drilling mast (204) is disposed between the lower drilling mast (202) and the base (110). The drilling mast structure (200) has a second position wherein the lower drilling mast (202) is perpendicular to the base (110) and the upper drilling mast (204) is aligned with the lower drilling mast (202).</p> |
