MOMENTVERKTYG FOR ATDRAGNING AV GENGADE FESTELEMENT

摘要

The invention disclosed herein relates to a tightening system for tightening an assembly including a threaded fastener including a wrench for applying torque and imparting rotation to the fastener. Associated with the wrench is a control system including measuring means for developing a first signal representative of the angular displacement of the fastener. A second signal representative of a constant incremental time is introduced along with the first signal to gradient calculating means which develops a signal representative of the slope or gradient of an angular speed vs. angular displacement curve which could be plotted for the particular assembly being tightened. When the gradient signal falls to a predetermined percentage of a maximum previously stored gradient signal, at the yield point of the assembly or some similarly significant point characterized by a significant change in slope on the angular speed vs. angular displacement curve, a control signal is generated stopping the tightening of the assembly.