TREE LOGGING METHOD AND HANGER-TYPE GRIPPING APPARATUS Russian patent published in 1999 - IPC

FIELD: forestry, in particular, logging in not easily accessible and remote regions, as well as on mountainous site with abrupt slopes. SUBSTANCE: method involves helicopter logging by means of grab hung to helicopter by cable, with cable length being chosen in accordance with ratio: L = (0.5 - 15.0) D, where L is cable length; D is diameter of helicopter rotor. Gripping apparatus adapted to be hung to aircraft, such as helicopter, has grab attached to cable. Grab has horizontal spindle for rotating levers (claws) and orientation changing device with air fans oriented in opposite directions to create pair of force components, whose longitudinal axes are extending in horizontal plane in parallel with axis of rotation of grab levers. Method allows logging of preliminarily worked (crosscut by grades) or uncut fell trees to be performed by means of helicopter without destroying plants growing in logging site and soil covering under different conditions due to reduced aerodynamic action of helicopter rotor (rotors) creating air streams. EFFECT: increased safety, wider operational capabilities and improved ecology control. 4 cl, 1 dwg