Patent ID: 8678210

Claim:
A mobile crane for intended use in lifting an object, comprising: chassis including a plurality of ground-engaging structures; a lifter carried by the chassis for use in lifting the object; and a telescoping boom assembly carried by the chassis, said telescoping boom assembly including a base boom section extending in a longitudinal direction and at least one telescoping boom section nested at least partially within the base boom section, said base boom section including a primary shell including a bottom wall, a top wall, and sidewalls, said walls together defining a first end with an opening for receiving the at least one telescoping boom section, a second end opposite the first end, and an intermediate portion corresponding to a conation point for connecting the lifter to the telescoping boom assembly; said base boom section further including a secondary shell connected to an external surface of the primary shell, said secondary shell is tapered in the longitudinal direction, extending from adjacent the connection point to adjacent the first end of the primary shell, and forming a gap between an inner surface of the secondary shell and the underlying external surface of at leas the bottom wall of the primary shell of the base boom section.