Abstract: A multi-section telescopic boom is disclosed having a base section supported for pivotal movement, a manual section telescopically received in said base section, a mid section, and a tip section which sections are progressively lighter from the base section to the tip section when excluding the weight of head machinery connected to the tip section. The heavy manual section is stored in the base section when a load to be transferred between two locations can be reached with the mid and tip sections extended thereby substantially decreasing the turning moment about the pivot axis due to the weight of the boom sections resulting in an increased load carrying capacity of the boom. The boom is preferably supported by a pendant line operatively connected to the outer end of the tip and base sections and trained within the boom to aid a single hydraulic ram to extend and retract selected sections of the boom.

Abstract: A telescopic boom is disclosed having a plurality of generally tubular boom sections each having its corners defined by angled corner plates converging upwardly and inwardly at equal angles relative to a central vertical plane containing the longitudinal axes of all boom sections when properly aligned. Boom shoes secured to the outer surfaces and near the inner ends of the angled corner plates of all boom sections except the largest section slidably engaging the adjacent angled corner plates of the next larger boom section; and similar boom shoes secured to the inner surfaces of the angled corner plates near the outer end of all boom sections except the smallest section slidably engaging the outer angled surfaces of the next smaller section.