Anti-sway hydraulic system for grappler

A hydraulic system for operating a grappler of a gantry crane, the grappler having a platform and at least one pair of opposite arms for lifting a load below the platform, each of the arms being mounted to the platform for pivotable movement on respective rotational axes which are parallel to each other, the arms being pivotable inwardly toward each other to clamp the load, the arms being, pivotable outwardly away from each other to free the load;

• the grappler being laterally moveable relative to the frame in a generally horizontal direction perpendicular to said axes;
• the hydraulic system comprising:
• a hydraulic actuator operably linked to pivot a respective one the arms;
• a first conduit in communication with the actuator such that fluid flows to the actuator through the first conduit to pivot the respective arm outwardly;
• a second conduit in communication with the actuator such that fluid flows to the actuator through the second conduit to pivot the respective arm inwardly;
• and
• at least one dampener operable to permit restricted flow through an associated one of the conduits away from the actuator caused by sway motion of the respective arm for dampening the sway motion.

A grappler for a gantry crane, the grappler comprising:

• a plurality of right arms and a plurality of corresponding left arms, the right and left arms being pivotably movable inwardly toward each other to clamp a load and outwardly away from each other to free a load;
• a plurality of hydraulic cylinders to drive the pivotable motion of the arms;
• a first conduit having a plurality of branches, each of the branches in communication with a first end of a respective one of the cylinders;
• a second conduit having a plurality of branches, each of the branches in communication with a second end of a respective one of the cylinders;
• and
• a plurality of dampeners, each of the dampeners disposed in a respective one of the branches of the second conduit to permit restricted flow caused by non-actuated outward pivotal movement of the respective arm.