Motorised trolley with two hoists in tandem
This was a modification made on an existing bridge crane. The trolley was replaced by an entirely new one, in which two 2000 kg hoists were installed.
Both hoists work so that the total load supported by them is 2000 kg. Since the crane has a load capacity of 2000 kg only, it is required to limit the total load. A device is measuring the individual load of each hoist and calculating the addition. However, it is allowed that each one of them can reach individually 2000 kg.
To achieve this purpose, each hoist is suspended from a load cell, which sends a signal to the electronic unit. This unit calculates instantaneously the individual and total loads and sends a signal to one or another hoist so as to inhibit its movement in case the maximum load is exceeded.
This bridge crane is used to lift and turn dies and moulds in a workshop.