Abstract: A proportionally extendable multi section boom crane is provided with an automatically erectable mast pivotally carried by one of the boom sections. The mast, which has a secondary sheave on the outer end thereof, normally rests in a stowed position adjacent the boom section on which it is mounted. The load line of the crane extending from the winch at the base of the boom section is trained over the secondary sheave, as well as sheave structure on the outermost end of the outer boom section. Elongated rod structure carried by one of the extendable boom sections outwardly of the crane has coupling means thereon engageable with the mast to initiate erection thereof after the proportionally movable boom sections have been extended a predetermined extent, normally after about 50% extension thereof.

Abstract: A mobile crane having frame structure supporting a boom and turret unit between the front and rear wheel axles of the crane is provided with four outrigger arms which are extensible to present an extended perimeter X-shaped pattern. The outrigger arms are each swingably attached to the crane for swinging movement from retracted positions adjacent the turret of the crane, to extended X-pattern defining dispositions where the ground engaging pads of the two forwardmost extended outrigger arms are generally aligned with the axis of the front axle of the crane, and the ground engaging pads of the two rearmost outrigger arms are generally aligned with the axis of the rear axle of the crane. Each of the outrigger arms is constructed such that the outer pad supporting ends move through an essentially upright path of travel as they approach, move toward and then move below ground level at the wheels of a crane.

Abstract: A mobile vehicle is provided with a multiple purpose material handling and working apparatus including a boom, and a tool supporting boom extension supported on the free distal end of the boom for rotation about an axis parallel to the longitudinal axis of the boom. The boom extension includes a body, a linkage structure movable between unpivoted and pivoted positions relative to the body, a coupling, and a linkage drive assembly mounted on and movable with the body for driving the linkage structure between unpivoted and pivoted positions. A rotary drive motor is supported on the boom for rotating the boom extension relative to the boom.

Abstract: In a multiple stage boom including a base boom and a plurality of relatively extensible and retractable boom stages, a system for displaying the load rating information relative to the boom includes an angle measuring assembly and a color coded boom and chart assembly. A plurality of separate markings are provided on and spaced from one another along the length of an intermediate boom stage of the boom in such a way as to be sequentially revealed when the boom stages are extended from a retracted position. Each of the markings are representative of the length of the boom at the point of extension of the boom where the marking is first revealed on the boom. A plurality of color sections extend along the intermediate boom stage, each of which is provided between a different pair of the markings and is colored differently than the other color sections to provide visible confirmation of the distance of extension of the boom.

Abstract: An improved, high strength extensible crane boom is provided which has a plurality of elongated, tubular, telescopically interfitted, longitudinally bowed, prestressed boom sections, along with a low cost method of fabricating the respective boom sections. Each boom section preferably includes an elongated upper plate having a channel structure welded to the underside thereof to form a polygonal body; permanent bowing of the body is accomplished as an incident to the welding sequence by virtue of asymmetrical heating and subsequent cooling of the metallic boom components. The boom sections are advantageously pentagonal in cross section, and the separate sides of the channel structures are simultaneously welded to the upper plates to evenly heat the plates and minimize torsional distortion of the sections.

Abstract: A color coding system for correlating the stages of a multiple stage, telescoping boom with the corresponding sections of a load chart and boom extension chart. The charts are arranged in separate sections which indicate, for various positions of the boom, the angle of the boom with respect to horizontal, its effective horizontal moment arm, and the maximum load that it can safely handle. The boom stages are each provided with a different exterior color, and the chart sections are colored such that each section is correlated with the boom stage to which it corresponds. Since the colors of the boom stages that are extended are readily visible, the color coding system facilitates reference to the proper sections of the charts and decreases the possibility of human error in reading of the charts.