Abstract: A mobile lifting apparatus having an extendable boom assembly supported by a plurality of hydraulic cylinders extending upwardly from a wheeled chassis, and further having a fork attachment coupled to the extendable boom assembly. The fork attachment is configured to engage palletized loads and permits such loads to be raised and transported upon extension of the hydraulic cylinders. The fork attachment includes a buttress assembly that remains relatively stationary as the boom assembly is horizontally extended and retracted. The fork assembly further includes a pair of forks that are pivotal relative to the buttress assembly around a generally horizontal axis. The forks are coupled to the horizontally extendable portion of the boom assembly so that extension and retraction of the boom pivots the forks to change the angular orientation of the forks relative to horizontal. Such angular movement of the forks facilitates engagement and disengagement of the forks with the palletized load.

Abstract: A mobile lifting apparatus has a chassis with front driving wheels and steerable rear wheels. A vertical mast comprised of a pair of extendible hydraulic cylinders is spacedly mounted on the front of the chassis. One or more jam stay cylinders are mounted on the chassis rearwardly of the vertical mast. A pair of extendable booms are mounted on the vertical mast and jam stay cylinders. The load may be attached to the end of the booms. A hydraulic or other power supply extends and retracts the boom and drives the driving wheels. A counterweight is mounted on the rear of the chassis and the chassis may be extended to increase the capacity and stability of the lifting apparatus.