Method for recording the torque and angle of rotation in impact screwdrivers

摘要

In a known method for recording the torque and angle of rotation in impact screwdrivers by means of a measuring arrangement which contains a progressive spring element, installed between the screwdriver and tool or in the tool itself, and an interrogation and evaluation unit, the first torque increase usually prevents an accurate recording of the actual torque as a function of the angle of rotation. In order to eliminate this shortcoming, it is proposed, according to the invention, to measure continuously the respective duration of the impact pulses which decreases with an increasing torque, to compare it with a predetermined minimum pulse duration assigned to the desired final torque and to switch off the impact screwdriver when an impact-pulse duration corresponding to this minimum pulse duration is reached. <IMAGE>