Mannesmann Aktiengesellschaft

Anton Munzenbrock

Klaus Behnke

The hoist, lifting apparatus or the like of our invention comprises at least one hoist motor, a protective controller for the hoist motor, and an overload safety device operating on the protective controller, wherein the overload safety device has a cable load force pick-up with a tension measuring bridge, an analyzer, and a mechanism for suppression of load peaks in periodic load fluctuations. The tension measuring bridge is connected with two connecting conductors to a bridge supply generator and has two output conductors for transmission of the output signal of the tension measuring bridge. The analyzer acts on the protective controller for the hoist motor. Between the analyzer and the tension measuring bridge is a frequency converter with associated frequency generator which changes the output signal of the measuring bridge into a periodic signal. The analyzer has at least one counter with an adjustable initial state, at least one analyzer controller and a frequency divider, which produces a periodic control signal as a gate pulse for the counter from a reference frequency of normal frequency. With the counter during the gate pulse the cycles are countable, which includes the periodic signal of the frequency converter. The controller is disconnected by the counter, when a given counting state during the gate pulse is equaled or exceeded. The gate pulse is so adjusted that it equals or exceeds the period of the load fluctuations.

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Dortmund, Germany

Anton Munzenbrock