| 摘要 |
<p>A power-driven apparatus for rotating a tubular member such as pipe includes a carriage for rotatably supporting a first rotatable member for receiving the tubular member, a second rotatable member for rotating the first rotatable member, and a bi-directional motor for rotating the second rotatable member in first and second directions to thereby rotate the first rotatable member in first and second directions. A pair of jaws for gripping the tubular member is pivotally mounted in opposed relationship to the first rotatable member, and roller bearings are carried by the second rotatable member for pivoting the jaws to engage the tubular member and through frictional contact with the jaws to rotate the tubular member and the first rotatable member in response to rotation of the second rotatable member in both the first and second directions. The second rotatable member is rotatably supported by and independently rotatable with respect to the first rotatable member.</p> |
