Crane’s motor trolley with two “tandem“ hoists

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 in 2000 kg. Since the crane has a load capacity of 2000 kg only, it is required to limit the total load. A device measures the individual load of each hoist and calculates the addition. However, it is allowed that each one of them can reach 2000 kg individually.

To achieve this purpose each hoist is hanged on a load cell that sends a signal to the electronic unit. This unit calculates instantaneously the individual and total load and sends a signal to one or another hoist so as to inhibit its movement should the maximum load be exceeded.

This bridge crane is used for lifting and turning over dies and moulds in a metalworking company.