Power tongs with improved hydraulic drive

摘要

Power tongs are described for making up and breaking apart joints of pipe. The hydraulic system of the tong comprises a tandem fluid motor which enables both forward and reverse operation of the tong in one of several selected speed/torque ranges by operating a pair of control handles. The open throat tong includes a door latching mechanism for automatically locking and unlocking the tong door when activating the tong hydraulic system. The tong dies come into gripping engagement with the pipe over a large composite arcuate angle to increase the pipe gripping ability of the tong.