HOIST Russian patent published in 1994 - IPC

FIELD: load hoisting mechanisms. SUBSTANCE: hoist has upper block including body, two shafts, four sprockets, and closed chain; lower block including shaft, sprocket and hook; closed chain passed over upper block and lower block sprockets to form loops. Shafts of upper block are parallel. Sprockets are rigidly secured on shafts in two parallel planes perpendicular to shaft plane. Positioned in one plane is closed chain of upper block, which imparts torque from one shaft of upper block to the other through sprocket. Second closed chain is positioned in second plane and is put on sprocket of upper block to form two loops, in one of which lower block is suspended. One of shafts of upper block and shaft of lower block are provided with mounting places for fastening handle or motor. Teeth ratio of upper block sprockets is selected so that running-on speed of closed chain working loop differs from speed of its running-around. EFFECT: enhanced efficiency. 3 cl, 2 dwg