Patent ID: 8720283
Filing Date: 2014-05-13
Classification: G01C,G01L

Abstract:
1. A variable torque-rate test joint for performance testing of rotary tools for threaded fasteners, comprising a screw-threaded nut and bolt assembly in a test rig, the assembly being adapted to be tightened by a rotary tool under test to compress a variable joint against a reaction surface of the test rig, characterized in that the reaction surface is an operative face of a hydraulic piston and cylinder assembly, and a hydraulic control is provided for the piston and cylinder assembly, including means for hydraulically extending the piston from the cylinder to an extended condition which defines a test position of the reaction surface, and means for hydraulically retracting the piston back into the cylinder to remove pressure on the reaction surface at the end of the test, to facilitate unwinding of the test joint for a subsequent test.