Patent ID: 8438954

Claim:
An apparatus for attachment to a line pull tong tubing joint make-up system on an oil rig, having tongs attached to two sections of pipe with one tong connected to a line pull apparatus, having a fluid-operated clutch connected to pressurized fluid source and the other tong connected to a piston-cylinder assembly, the apparatus comprising: a pressure transducer connected to the piston-cylinder assembly to sense the internal pressure in the piston-cylinder assembly and generate an output signal; a valve operable in response to a valve control signal, the valve located in the connection between the clutch and the pressurized fluid source movable between a first position, permitting fluid flow from the fluid source to the clutch and a second position, interrupting flow between the fluid source and the clutch; and a controller operably connected to the valve and transducer and programmed to provide a valve control signal to move the valve between the first and second positions in response to the output signal from the pressure transducer, whereby the line pull apparatus is engaged and disengaged.