| 摘要 |
Damage to pipe resulting from non-uniform application of gripping forces is minimized by modified power tongs employing pivoting jaws which automatically adjust to the circumference of the pipe. The pivoting jaws pivot about mounting pins which pass through an elongated aperture in the jaw. The aperture is elongated in a direction which allows the arcuate pipe-gripping surface on the jaw to align itself concentric with the outer surface of the pipe so that the gripping force applied by the jaw is uniformly distributed over the arcuate pipe-gripping surface of the jaw.
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