Abstract: An apparatus is disclosed for maintaining a predetermined mast-boom working angle of a pendant supported boom substantially constant during extension and retraction of the boom. One embodiment of the invention includes control means connected between the boom and the mast for detecting slight angular changes and actuating power means for paying out or drawing in sufficient pendant to return the mast-boom angle to a predetermined angle. Another embodiment utilizes electrical controls having a first potentiometer capable of detecting linear changes in the effective boom supporting length of the pendant and another potentiometer for detecting linear changes in the length of the boom, said potentiometer sending output signal ratios which vary from a predetermined output signal ratio for actuating power means that takes up or pays out sufficient pendant to return the boom to the predetermined mast-boom working angle and returns the output signal ratio to said predetermined ratio.

Abstract: A coupling and latching mechanism for a multisection extensible boom that includes a manual section and is operable from a remote location such as the cab of a crane. The mechanism includes pairs of spaced jaw type couplings secured to adjacent boom sections and adapted to be selectively coupled to the piston rod or the like of an extensible power means for operating the boom either with the manual section extended or retracted. Remotely controlled latch means are provided to latch the manual section in a plurality of extended positions, or in a retracted position.

Abstract: A telescopic boom is disclosed which is pivotally supported by its base section for movement about a horizontal axis. The boom is supported by a live mast through multi-part pendant lines, which pendant lines are each reeved over sheaves attached to the boom at the forward end of the base section and at the forward end of another boom section to support the boom at a plurality of points forwardly of the live mast. The forward end of each pendant is preferably received within the boom over sheaves journaled on the cylinder case of a boom extending ram and on selected sections of the boom. The multi-part pendant supported boom reduces boom droop caused by extension of the boom approximately 50% of that of a boom supported at a single point by each pendant line.

Abstract: An articulated boom and assembly comprising:(a) a lower boom arm;(b) an upper boom arm foldable over the lower boom arm and pivotal with respect to the lower boom arm;(c) hydraulic cylinders positioned between the boom arms and having piston rods extending therefrom, the hydraulic cylinders with the piston rods, pivotally secured at one end to each boom arm intermediate the boom arm's ends, one hydraulic cylinder being pivotally secured to the underside of the upper arm and the other cylinder pivotally secured to the upper side of the lower arm facing the upper side when the upper arm is folded over the lower arm;(d) a linkage for pivotally connecting the upper arm, lower arm and hydraulic cylinders, the linkage comprising three points of connection, the points when linearly connected forming a triangle with the points of connection forming the apexes of the triangle, with:(i) one apex of the triangle directed towards the hydraulic cylinders and piston rods between the upper and lower boom arms and the linkag

Abstract: A loader vehicle boom arm assembly incorporates a pair of box section boom arms in which the top plate of each box section boom arm has a cross sectional shape such that the upper surface is provided with an arcuate surface that directs foreign objects encountering the arcuate top surface off the boom arm.

Abstract: A hydraulic control system which is of an open center parallel circuit arrangement for aerial boom devices with two return lines, said system having control valves for upper and lower boom arms, wherein the lower boom control valve overrides the upper boom control valve. The system includes a valve connected to a pump actuating engine and responsive to hydraulic pressure to increase the speed of the fluid pump when the flow or pressure in one return line is reduced due to diversion of fluid within the system into the second return line. The system also includes a normally open relief valve carried by the boom supporting turntable adjacent its pivotal connection to the lower boom and operable to control a winch actuator and to deactivate said winch actuator when the boom is in an unstable position.

Abstract: A truck vehicle carried boom system for lifting, transporting, and depositing a load of particulate material such as powder, granules or seeds into storage bins in material dispensing aircraft, including a telescoping boom structure pivotally mounted on support structure which in turn is rigidly secured to the vehicle frame. The boom includes provision for removable carrying a hopper form of load bag. An extensible piston-cylinder hydraulic motor is utilized to obtain various pivotal positions of the boom. The boom telescope disposition is maintained by a mechanical safety pin. The boom is extended and retracted by inertial forces generated by vehicle manipulation. As an auxiliary device a boom safety bar, hydraulically operated is secured to a side portion of the truck bumper structure to provide a safety block when the boom is in the aircraft loading position.

Abstract: An improved hydraulic crane comprising at least one lifting cylinder to pivot the crane arm in a vertical plane relative to the crane post. A pressure-fluid line associated with the cylinder is connected to a movement-damping accumulator. In addition, a non-return valve is inserted between the cylinder and the accumulator to allow flow of pressurized liquid in one direction only away from the cylinder. A drainage line is connected to the accumulator, said drainage line incorporating a pressure-limiting valve. Owing to this arrangement, any added loads that arise as a result of sudden, shock-like pressures may be absorbed upon pressure relief in the accumulator without imparting jerky return movements to the crane arms.

Abstract: A log skidder including a vehicle having a frame with front and rear ends, ground engaging devices on the frame so that the vehicle may traverse the underlying terrain, an elongated boom on the frame and mounted thereto for pivotal movement about a generally horizontal axis between an upright position at least adjacent the rear end and a lower position intermediate the ends, a log engaging device, a lever mounting at one end the log engaging device and horizontally pivoted at a location remote from the lever one end to the boom at a location spaced from the horizontal axis, the lever one end extending rearwardly with relation to the frame, a motor on the frame for moving the boom between the positions thereof, and a linkage for maintaining the lever one end directed generally rearwardly for all positions of the boom on the frame.

Abstract: A boom arm of a boom assembly is formed of a pair of side walls integrated into a box boom structure where the top and bottom plates are roll formed with transition edges providing a weld bed for welds attaching the side walls to the top and bottom plates. The particular cross sections of the top and bottom plates provide a weld blow-through preventing barrier and also dimensional guidance and tolerance control during assembly of the boom arm.

Abstract: A hydraulically actuated hoist adapted for mounting on a farm tractor, the hoist including a base of generally inverted T-shaped configuration having a horizontally extending portion and a vertically extending portion, a telescopic boom having one end portion pivotally connected to the vertically extending portion of the base, the hoist also including a pair of downwardly extending support legs fixed to the horizontally extending portion of the base, and an elongate support post pivotally connected to the end portion of the boom remote from the base, the post being adapted to overlie the boom and being pivotable to a vertically extending position whereby the post and the legs cooperate to form a tripodal support for the hoist.