| 摘要 |
1. A tackle comprising pulley-block means (9) having an upper block (6) carried by a frame (10) and a lower block (27) carrying a hoisting hook (15) or like member and suspended from below the upper block (6) through at least one flat flexible line (5) passing around return pulleys (4) which are carried by the two blocks (6, 27) and at least one end (23) of which is attached to the drum (21) of a drum-pulley (2) driven by a rotary driving member (1), characterized in that the upper block (6) is mounted on the frame (10) in such manner as to be freely pivotable about a horizontal axis (X-X) substantially tangent to upper parts of grooves of two successive return pulleys (4), namely that pulley (4b) carried by the upper block (6) which the flat flexible line reaches first in travelling away from the drum-pulley (2) and that pulley (4) which succeeds the last-mentioned pulley in a direction toward the drum-pulley (2). |
