Mannesmann Aktiengesellschaft

Konecranes Global Corporation

Terex Mhps Gmbh

Klaus Behnke

Anton Munzenbrock

A method and assembly for operating at least two lifting gears in a group operation, where each lifting gear has a hoist via which a respective cable or chain can be raised or lowered. The hoists are first operated in a synchronous operating mode to perform a common lifting procedure to move a load supported by the hoists. At least one of the hoists involved in the common lifting procedure is then deactivated to switch from the synchronous operation into an individual operation or a multi-operation, with at least one of the hoists remaining activated to carry out a lifting or lowering process relative to each deactivated hoist. A load value is then determined for the at least one deactivated hoist and compared to a predetermined threshold value of the at least one deactivated hoist.

Method for operating at least two lifting means in a group operation, and assembly comprising at least two lifting means

A method and control assembly are provided for operating at least two lifting devices, such as cranes, in group and normal operation modes. Each lifting device has a control system connected to a control switch, and the lifting devices are controlled through a common bus. In group operation, the lifting devices are jointly controlled through the bus by one switch. To operate at least two lifting devices in parallel, one of the switches is active in the group operation and the remaining switch or switches are passive. To prepare for group operation, normal operation is deselected by all but one of the control switches to release a remaining switch for log-in to the active state for group operation. To prepare for normal operation, group operation is deselected and normal operation is selected at the active switch before the other switch or switches are released for logging into normal operation.

Method and control assembly for operating at least two lifting devices, in particular cranes, in parallel

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

Klaus Behnke