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: In a loading crane comprising a crane post on which is pivotally mounted a crane arm or boom, and a main hydraulic piston-and-cylinder unit the lower end of which is pivotally connected to the base of the crane post and the upper end of which is pivotally connected to the inner crane arm end to effect raising and folding movements of said arm, a device, preferably in the form of an auxiliary piston-and-cylinder unit, arranged to displace the upper fulcrum of the main cylinder unit away from the crane post, past an imaginary line extending between the fulcrum pin on which the crane arm pivots relative to said post and the lower fulcrum point of the main cylinder unit.

Abstract: A means to damp the oscillating movements of a hoisting device suspended in a link the upper end of which is in the form of a cylinder in which is pivotally mounted a first horizontal shaft on the outer end of a crane jib and the lower end of which is in the form of a fork member supporting between its legs a second horizontal shaft in a second cylinder forming the upper end of a holder supporting the hoisting device. The damping is affected by spring-actuated brake shoes acting against its respective cylinder face. Rotationally mounted clamp bolts are arranged when turned, preferably over 180.degree., to increase the tension of said spring means.

Abstract: An improved joint and method of providing such a joint between the upper and lower portions of a rotatably driven crane post, comprising a sleeve-shaped member formed internally with screw threads and provided at the lower end of the upper position, a pin provided at the upper part of the lower post portion and formed externally with screw threads matching the sleeve member threads, and a collar on the lower post portion below the pin against which collar the sleeve-shaped member is pressed upon screwing together of the lower and upper post portions to form said joint.

Abstract: A double-acting hydraulic cylinder having two concentrically disposed jackets and at least two pistons arranged for coaxial movements relative to said cylinder, one of said pistons being annular and arranged for axial movement in an annular chamber, means being provided to communicate a space between the inner piston and an end section of the inner jacket, with the opposite end of the annular chamber in a manner ensuring that the operative, pressurized medium actuates the two pistons for displacement thereof in a predetermined order and at approximately the same speed in the outwards and inwards directions of said pistons.

Abstract: In a hydraulically operated loading crane of the kind comprising a rotatable crane post, an inner crane boom pivotally mounted at the upper end of said post, a jib pivotally mounted to said boom, and an extension boom mounted for longitudinal displacement relative to said jib and supporting at its outer end a load hoisting tool, an electronically programmable control system incorporating encoders capable of measuring the relative movements of the crane parts and arranged to store the measured values in a memory, and a comparator means arranged to compare signals representing pre-programmed patterns of movements with the signals received from said encoders so as to effect feeding of the required quantity of pressurized medium to the various hydraulic means to obtain the desired, pre-programmed patterns of movements.

Abstract: In an industrial robot incorporating a control system by means of which the robot may repeat automatically a desired movement pattern, two hydraulic cylinders to pivot the robot pivotable arms in a vertical plane. The hydraulic cylinders are interconnected by an articulation means which may be disconnected from the robot arms so as not to take part in the arm movements during programming, but again be connected to the robot arms to allow the associated hydraulic cylinders to perform their function when the robot is to operate according to the chosen programme.

Abstract: In vehicle-mounted cranes comprising a hoisting arm consisting of two hingedly interconnected arm sections the outer one of which is equipped with a longitudinally displaceable boom, a bracket removably attachable to the outer end of said boom and to which bracket is hingedly connected a rocker arm with a longitudinally displaceable boom with means thereon to support a load, in addition to which two hingedly interconnected links are provided to likewise connect said bracket with said rocker arm. Locking bolts secure said bracket to the first-mentioned boom, whereby the bracket together with the rocker arm and the boom thereon may be dismounted from the rest of the crane as a unit which may be attached to the crane whenever increased lifting height is required.

Abstract: A flexible connection between the crane base of a truck-mounted loading crane and a transverse support bridge mounted on the vehicle chassis frame, said connection comprising a support arm formed on the crane base, the free end of said arm formed as a hub into which is inserted an elastic joint member secured to said bridge, said arm end engaging with some play in a lateral groove in the bridge.

Abstract: A rotator of the kind intended to be positioned between a crane hoisting boom and a lifting tool suspended in said boom and provided with hydraulic tool actuating means. The rotator is mounted on a vertical shaft in a manner permitting it some flexion sidewise without occurrence of fractures or breaks causing leakage of the pressurized medium and also in a manner making exchange of the sealing rings easy in that the rotator need not be dismantled for this exchange.

Abstract: A remote-controlled loading hook is provided with a hook-shaped means having its upper end journalled on a pin in the upper portion of a casing. The hook-shaped means is adapted to be swung with its lower end, shaped as a hook, into the casing. The casing is freely suspended in a cable, a chain or the like. The casing has an opening in its lower part and the carrying hook, which has a locking abutment, is adapted to bridge said opening. A seat is arranged on either side of the opening to support the carrying hook in position of use. The hook-shaped means is suspended on the pin in such a way that at the lifting of the casing and the loading of the hook-shaped means the latter can move in vertical direction relative to the casing to a position in which one of the seats catches behind the locking abutment of the hook.

Abstract: In hydraulically operated loading cranes, particularly loading cranes comprising multiple loading arms, a blocking device in the form of a return piston arranged, upon occurrence of an excessive pressure in the master cylinder, to prevent operation of piston-and-cylinder units actuating the loading arms in a direction away from the loading crane post but permit operation in the reverse direction, i.e. movement of the loading arms towards the post. The blocking device thus ensures that the moment of loading on the crane arms never reaches a value involving risks that the crane will tip over.

Abstract: In support legs intended for mobile cranes and comprising telescopically displaceable jib sections, an arrangement permitting maximum jib length while retaining complete stability of the crane, said arrangement including a support arm extending in the direction of the displacement of said jib sections and supported at one end by the crane base and abutting at its opposite end against the inner jib section, said support arm additionally provided with means to limit the degree of extension of said inner jib section.

Abstract: A means to damp the oscillating movements of a hoisting device suspended in a link the upper end of which pivotally mounted about a first horizontal shaft on the outer end of a crane jib and at the lower end of which the hoisting device is pivotally mounted about a second horizontal shaft. A sector-shaped brake disc is mounted at the upper articulation point, the centre of said disc being situated in or close to the centre of said first shaft. At least one brake shoe is provided at the crane jib and arranged to be pressed against the disc at a distance from said first shaft, whereby the desired damping effect is obtained.