US Patent 7878347 Lifting apparatus with compensation means

The present disclosure relates to a lifting assembly such as a jib crane or similar apparatus having an articulated arm assembly and a flexible means for connecting a load to an actuator. The lift arm assembly forms an articulated cantilever boom, which is extensible so as to traverse a suspended load within a work cell area. The lift arm assembly further includes a first and second member pivotally connected to one another whereby an inclined plane (e.g., a cam) at the pivot point of the articulating arms provides a vertical displacement of the secondary arms thereby moving the distal end of the secondary arm to counterbalance inherent forces acting thereon.