| 摘要 |
An iron roughneck has a pair of upper jaws carrying pipe gripping dies for gripping tool joints. The jaws have recesses formed on each side of the pipe gripping dies to receive spinning rollers. By positioning the spinning rollers in the upper jaws at the same level as pipe gripping dies, the spinning rollers are able to engage the pipe closer to the lower jaws and thus can act on the tool joint rather than on the pipe stem.
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