Patent attributes
A clamp assembly, for mounting around a tool joint coaxially joining cylindrical upper and lower workpieces, comprises an upper collar assembly and a lower collar assembly, each having semi-cylindrical left and right collar segments. The left and right collar segments of each collar assembly are removably connectable to each other by threaded fasteners to form the collar assembly. The upper and lower collar assemblies are coaxially mountable around the upper and lower workpieces, respectively, such that tightening the fasteners will urge the upper and lower collar assemblies to grip the upper and lower workpieces, respectively, and thus to provide increased resistance to relative rotation between the two workpieces about the tool joint axis. The upper and lower left collar segments, and/or the upper and lower right collar segments, may be interlockingly and radially slidable relative to each other to accommodate differences between the outside diameters of the two workpieces.