Abstract: The present invention relates to a clamping device for clamping a mandrel to an elbow or pipe as well as to a torque-reacting device between a power unit housing and the mandrel. The torque reacting device has a pair of torque reacting keys mounted in a non-rotatable portion of the power unit housing, each of the keys having an end portion with converging opposite sides. The end portions of the torque reacting keys extend into correspondingly shaped, axially extending grooves formed in opposite sides of the mandrel. The opposite sides of the grooves are outwardly diverging and define an included angle approximately equal to the angle between the converging sides of the torque reacting keys. Adjusting screws are provided for each of the torque reacting keys. The clamping device has a plurality of clamping pins, each pin having a generally cylindrical shape with a hemispherical end portion defining a plurality of concentric ridges.

Abstract: The present invention relates to a clamping device for clamping a mandrel to an elbow or pipe as well as to a torque-reacting device between a power unit housing and the mandrel. The torque reacting device has a pair of torque reacting keys mounted in a non-rotatable portion of the power unit housing, each of the keys having an end portion with converging opposite sides. The end portions of the torque reacting keys extend into correspondingly shaped, axially extending grooves formed in opposite sides of the mandrel. The opposite sides of the grooves are outwardly diverging and define an included angle approximately equal to the angle between the converging sides of the torque reacting keys. Adjusting screws are provided for each of the torque reacting keys. The clamping device has a plurality of clamping pins, each pin having a generally cylindrical shape with a hemispherical end portion defining a plurality of concentric ridges.