Working device for drilling, cutting and screwdriver instruments used for medical purposes

Abstract

The invention concerns an electric drive device for medical applications, especially for driving drills, cutting instruments and screw drivers. Such endo-instruments have predetermined working rotation areas and comprise maximally permissible torque load limits according to the materials thereof. The drive device is equipped with a stepping motor in order to avoid exceeding the torque load limits. The stepping motor disconnects when the maximum torque limit of the stepping motor is fixed below the torque load limit of the instrument. In order to precisely set the torque load limit, a calibration is carried out within the limits of a no-load operation during which the efficiency of the driving shaft up to the instrument is detected, and with it, the value of the current is determined for a zero torque.

Dependencies are inferred from the claim text.