Back-up power tongs and method

摘要

Improved back-up tongs are provided for use with powered rotary tongs for making and breaking sections of drill pipe in a drill string. The tongs include a pair of jaw members which are slidably and radially driven into engagement with the drill pipe by levers having one end urgeable against corresponding ones of the jaw members, and having their other end hingedly coupled to a hydraulically driven push rod. Improved means are included for coupling the back-up tongs into close releasable association with the rotary tongs, and are further included for providing a more accurate measurement of the torque being applied to the pipe member during make-up of the drill string.