Abstract: A boom assembly includes a boom arm movable away from and into a first position used for storage and transport of the boom assembly, and a boom latch positioned adjacent a free end of the boom arm when the boom arm is in the first position for restricting the movement of the boom arm out of the first position during transport of the boom assembly. The boom latch includes a lock member, a latch hook movable from a closed position wherein the lock member is retained in the latch hook to an open position wherein the lock member is not retained in the latch hook, and a latch hook control unit for alternately locking the latch hook in the closed position and unlocking the latch hook so that the latch hook is free to move from the closed position to the open position.

Abstract: A hoisting boom assembly comprises an upright column being piviotable by a rotary actuator and a first and second boom, the first boom pivotally mounted by its first end on upright column and by its second end on second boom; the second boom having its first section and its second section journalled to be pivotable in a vertical plane; a horizontal shift mechanism as well as a horizontal shift actuator for carrying the free end of the second boom in a horizontal direction; and an actuator fitted between upright column and the first boom for pivoting the first boom. In order to improve its performance, the hoisting boom assembly further includes compensating means for equalizing the forces caused by the operation of a hoisting boom assembly, particularly in situations following and preceding a first and/or a second extreme position assumed by a second boom.

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: A hydraulic excavator includes a boom comprising an articulated first and second boom member, an arm, a bucket, a boom cylinder for operating the boom, an arm cylinder for operating the arm; and a bucket cylinder for operating the bucket. The boom cylinder is cooperatively associated with the boom to establish a geometry wherein, during operation, the axis of the boom cylinder can never pivot rearwardly across a dead point of the boom and therefore eliminate the possibility of dead locking of the boom during operation.