MICROPROCESSOR CONTROL YIELD POINT TIGHTENING SYSTEM

摘要

A method for tightening a fastener to yield point wherein areas under a torque-angle curve each include a constant abscissa and are successively measured. A decrease of area in a subsequently measured area, indicates that yield point of the fastener has occurred. Upon attainment of yield point, the final torque and angular rotation parameters are checked to determine if pre-set values have been realized. The method includes a preliminary torque-angle curve measurement to determine if certain conditions are satisfied; failure to satisfy such conditions, aborts the tightening operation.