Abstract: The invention relates to a machine for dropping heavy weights on the ground for carrying out processes of dynamic compaction or dynamic consolidation wherein a brake is provided on the hoist drum which can be actuated automatically after a given period of time has elapsed after the release of the hoist drum brake to drop the weight.

Abstract: An earthmoving machine primarily for land drainage and irrigation purposes has a pivotally mounted boom (8) carrying an arm (12) pivoted at one end to one end of the boom and having a bucket (14) or the like attached at its other end. At the end of the arm which is pivoted on the boom a quadrant (20) is formed around which passes a pendant cable (18) attached to a counterweight (22) which is slidable on the rearwardly extending end of the boom, the counterweight, and thus the arm, being moved by a ram (24) so that radially outwards movement of the arm (12) is accompanied by outwards movement of the counterweight (22) along the end of the boom in the opposite direction to balance the machine. A draw-in rope or cable (26) is attached to the free end of the arm in order to draw-in the arm towards the pivot axis of the boom, the ram (24) and draw-in rope winch (25) being hydraulically connected so that the one is operative when the other is in neutral and vice versa.

Abstract: The invention relates to a method of removing a slewing ring (3) from a pedestal-mounted crane (2). A carriage (14) is positioned on a pair of elongate guide members (9) which lie substantially parallel, both to one another and to the plane of the slewing ring (3), and which extend alongside the pedestal (14). The crane (2) is raised relative to the pedestal (4) by means of jacks (7) and the carriage (14) is moved to a position beneath the crane (2). The slewing ring (3) is then positioned on the carriage and withdrawn on the carriage from beneath the crane.

Abstract: A crane has a hoist rope which passes over a boom to a drum driven by a hudraulic motor and including a brake. The crane includes means for releasing the brake when the free end of the rope is a given distance below the crane, and has means for relieving hydraulic pressure from the motor in response to the horizontal radius of the free end of the rope so that at a given radius the motor can lift only a given maximum load.

Abstract: The invention concerns a bearing assembly having inner and outer bearing rings and two axially spaced coaxial annular passageways between said bearing rings and a number of rollers retained within said passageways, some of said rollers being inclined in one sense to the axis of said bearing and the others of said rollers being inclined in the opposite sense to said bearing axis.