Tractor mounted apparatus for performing aerial work tasks

Abstract

An aerial work task apparatus comprises a pair of laterally spaced lift arms pivotally mounted on the frame of a tractor and a double-acting lift cylinder pivotally interconnected between the frame and each lift arm. A platform, adapted to carry a workman thereon, is pivotally connected to the frame and to the lift arms by linkage means which function to raise and lower the platform substantially vertically above the tractor and to maintain the platform relative to ground level. In a first embodiment of the this invention, the linkage means comprises first and second pairs of links pivotally interconnected between the lift arms and the platform to form a parallelogram type linkage and a third pair of links pivotally interconnected between the first pair of links and the frame of the tractor. The third pair of links and the lift arms form a second parallelogram type linkage to aid in the above mentioned maintenance of the platform in parallel relationship relative to ground level. In a second embodiment of this invention, the linkage means comprises the above-mentioned first and second pairs of links and a tilt linkage normally associated with a loader bucket is substituted in lieu of the third pair of links. In both such embodiments, the platform is universally connected to the first pair of links by a single ball and socket connection whereas each of the second pair of links is connected to the platform by a ball and socket connection to thus provide a threepoint adjustable support for the platform, i.e., the second links each constitute a double-acting hydraulic cylinder.

Dependencies are inferred from the claim text.