Hilti Aktiengesellschaft

Gottfried Benz

Wolfgang Millauer

Franz Hoyss

Heinrich Pauli

Drive control for a drilling device including a universal motor is arranged so that the total available mains voltage is applied when a fraction of the motor torque, available for the full work range of the device, is reached. If a higher torque is desired, the motor torque/rotational speed curve follows the natural characteristic line until a load point is reached where current limitation occurs. Accordingly, as the motor speed decreases as the normal work range is exceeded, the operator of the drilling device is signaled concerning the load state due to the noise developed in the drilling device.

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Schaan, Switzerland

Gottfried Benz