Screwdriver for the defined tightening of screws by means of a tool operated by auxiliary force

摘要

Torque and rotary angle are measured in a screwdriving tool. Several "windows" through which in the normal case the torque/rotary angle characteristic has to pass are in each case predetermined by maximum and minimum torque and maximum and minimum rotary angle. A computer checks step by step whether the characteristic curve runs through all these windows. If the characteristic curve does not run through all the windows, the screwdriver is switched off and an error signal is transmitted. After the last step, the screwdriver is switched off and a check is made as to whether the characteristic curve ends in the last window after the after-running due to inertia. The behaviour of the characteristic curve is shown on a monitor.