Patent ID: 7357263

Claim:
An articulating jib unit adapted for coupling with the upper end of a primary boom, said jib unit comprising: a jib arm; a base including coupling structure for said coupling of the jib unit to said primary boom upper end; and an articulating assembly operably coupled between said base and jib arm to selectively move the jib arm relative to said base, said assembly including, a first piston and cylinder assembly having a rod presenting a rod end and a cylinder presenting a cylinder end and generally extending from the base, a second piston and cylinder assembly having a rod presenting a rod end and a cylinder presenting a cylinder end, an arm, having first and second ends, disposed between the first and second piston and cylinder assemblies, and first and second mounting units associated with the first and second ends of said arm, said one of the first assembly's rod end and cylinder end being pivotally associated with the base, and the other of said first assembly's rod end and cylinder end being pivotally associated with one of the first and second mounting units, said one of the second assembly's rod end and cylinder end being pivotally associated with the other of said first and second mounting units, and the other of said second assembly's rod end and cylinder end being pivotally associated with the jib arm, said first and second piston and cylinder assemblies being positioned approximately parallel to each other throughout extension and retraction of the rod ends of the assemblies and further oriented such that the rods of each of the assemblies extend in generally opposite directions.