Container-lifting spreader with drive for the telescopic movement of spreader's beams protected against damage by collision

摘要

A container-lifting spreader includes at least two beams movably supported in a housing and provided a drive by which the beams can be driven in telescopic movements for adjusting the length of the spreader. The drive includes an electric motor and a pusher acting on the beams, the pusher interconnecting the beams for simultaneous telescopic movements in mutually opposite directions in the longitudinal direction of the spreader, and a power transmission operatively coupled between the motor and the pusher. The power transmission includes an input shaft carrying an external gear ring driven by the motor, and an output shaft likewise carrying an external gear ring that operates the pusher, the gear rings in mutual engagement forming an angle gear arranged with an irreversible mesh of teeth such that rotation of the input shaft causes rotation of the output shaft whereas the reverse is prohibited by the irreversible mesh of teeth.