This comprises a driving block in the back section of the boom for fixed-reach models, or it is mounted on a self-driving carriage on variable-reach models.
This driving unit contains an electric motor with an electromagnetic brake that acts on the gearbox inside the elevating cable’s coil drum.
It also has cut-out switches at the end of the line in order to avoid accidents caused by the hook having too much travel.
Turning system
There is a special bearing between the boom and the pivot for large-diameter cranes with an exterior cog to facilitate the rotation of the load.
This bearing can control the potentially unbalancing momentum of a moving load, wind and compression strain with its own weight and load.
The rotation gearbox is firmly fixed to one side, with a sprocket wheel that is fixed to the sprocket attached to the boom, making the boom revolve when the motor is in use.
This mechanism allows a 360o range of movement that is controlled from the bottom of the crane.
Range mechanism
Models from the superior range (10 and 12MT) are equipped with a driving carriage that moves along the boom. It contains the elevation driving unit as well as the mechanism for moving the carriage.
Reach varies between a minimum of 2.5m to a maximum of 12m.
The minimum range possible on standard models is 2.5m and the maximum is 7m. This can be extended to 12m, subject to technical studies.
The mobile hoist carriage moves on rollers over the tracks on the top of the boom.
There is a special bearing between the boom and the pivot for large-diameter cranes with an exterior cog to facilitate the rotation of the load.
Models from the superior range (10 and 12MT) are equipped with a driving carriage that moves along the boom. It contains the elevation driving unit as well as the mechanism for moving the carriage.