| 摘要 |
A jaw assembly for apparatus for gripping pipes, the apparatus being of the type having automatic means for exerting increased gripping force upon application thereto, is provided with a member having a concave surface which cooperates with a gripped pipe to override the automatic means for exerting increased gripping force. Having such a member, the jaw assembly of the present invention can exert a predetermined maximum gripping force on a gripped pipe notwithstanding amount of torque applied to the apparatus. Considering angular relationships involving jaw cam angle, the present invention can be manifested in an increasing cam angle jaw for power tongs.
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