Tractor-mounted lifting assembly, to drag fallen tree trunks, has a swing carrier arm and cable deflections rollers to act as pulleys for the lifting cable in a low cost structure

摘要

The assembly to drag fallen tree trunks, using a tractor and the like, has a triangular carrier arm (2) on a swing mounting with height adjustment at the tractor. An initial cable deflection roller (17) is at the tractor, and a second cable deflection roller (9) is at the carrier arm at a gap from the bottom. A cable passes around the rollers, in a pulley structure, and the free cable end has a hook (21) for lifting the load. Vertical and/or swing movements of the carrier arm change the gap between the rollers, so that the free length of the cable is greater than the roller gap. The upper linkage is a hydraulic or pneumatic piston/cylinder unit (15).