ACTUATOR DRIVEN SLEWING MECHANISM FOR TIMBER PROCESSING WORKHEAD

摘要

There is provided a slewing assembly for a timber handling apparatus of the type having a workhead connected to a support structure. The workhead is rotatable about a slew axis with respect to the support structure. The assembly provides a slewing mechanism for relative rotational movement of the workhead and the support structure about the slew axis. The assembly also provides a drive mechanism for imparting the relative rotational movement of the workhead and the support structure. The drive mechanism comprises two actuators, each actuator having a fixed end and a moveable end, the moveable ends of the actuators being linearly extendible and retractable with respect to the fixed ends of the actuators along an actuating axis. One end of each actuator is rotatably attached to the workhead and the other end of each actuator is rotatably attached to the support structure. Each actuator is positioned to apply a force to the slewing mechanism at a point radially distant from the slew axis upon extension and retraction of the moveable end of the actuator with respect to the fixed end of the actuator. This causes the relative rotational movement of the workhead and the support structure. The actuators are each positioned such that the actuating axes associated therewith do not all intersect the slew axis at the same time during the relative rotational movement of the workhead and the support structure.