| 摘要 |
The present invention provides back-up power tongs (1) for holding a tubular member (2) against rotation of a connected tubular member. The back-up power tongs comprise a body (3) with a front section for receiving the tubular member and a plurality of jaw members (5, 7) for engaging the tubular member. The jaw members are positioned to form a substantially closed perimeter around the tubular member and at least one of the jaw members is a pivotal jaw (7), moving in a pivotal path to engage the tubular member. An alternate embodiment provides two pivoting jaws (107a, 107b) and a locking mechanism (100) attached to the end of the pivoting jaws such that the pivoting jaws can be securely interlocked. The improved back-up tongs should not require the tong body to virtually enclose the pipe and thus will allow the improved back-up tongs to be considerably smaller.
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