Power tong with sliding jaw

摘要

A power tong ( 1 ) or back-up tong has a sliding jaw assembly ( 6 ) that may be advanced into the throat ( 4 ) of the tong for engagement with a pipe. A camming surface ( 11 ) on the inside circumference of the ring gear ( 10 ) advances the sliding jaw assembly into full engagement with the well pipe when the ring gear ( 10 ) is rotated with respect to the jaw assembly.