Mannesmann Aktiengesellschaft

Michael Hulsmann

Anton Munzebrock

Stefan Elspass

Rolf Koschorrek

A process and apparatus for positioning an object being moved along a path to a destination using a pole changing three-phase induction motor having at least two fixed driving speeds. The object is initially accelerated along the path of movement to the highest driving speed of the motor, during which the acceleration curve is determined and stored. The acceleration data is then used to calculate the location along the path in advance of the destination at which the motor is switched off and braked until reaching the next lower driving speed, whereupon the motor is operated at the next lower driving speed for a predetermined path length. The motor is then again switched off and braked until its driving speed reaches zero closely proximate the destination, at which point a motor in a gear assembly attached to the motor is operated for final low speed positioning of the object at the destination with a high degree of accuracy. The calculation of the initial switch-off location using, in the preferred embodiment, the dynamically-determined acceleration curve results in rapid and highly accurate object positioning without the need for undesirable buffer paths.

Process and apparatus for positioning an object

A process and apparatus for determining a load on a lifting mechanism including a load measuring device and a three-phase induction motor operable for lifting and lowering the load. The effective power consumption of the induction motor is determined by the load measuring device based on a measured current and measured voltage of the induction motor. The measured effective power consumption is then compared with a reference power, which is calculated as the power output of the induction motor driving a nominal load of the lifting mechanism, to calculated an instantaneous load on the lifting mechanism. The inventive apparatus and process advantageously requires no modifications or additions to load carrying parts of a lifting mechanism or carrying gear and provides accurate real time measurement of the load.

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Herdecke, Germany

Michael Hulsmann