Patent ID: 7395899

Claim:
A system comprising: a first fixed pulley attached to a non-portable structure; a second fixed pulley attached to a base of the structure below the first fixed pulley; a moveable pulley; a closed loop of cable installed around the first fixed pulley and the moveable pulley; a load attached to the loop; a traction winch around which the loop is operatively installed to lift the attached load; a cable connected to the moveable pulley and trained around the second fixed pulley, the cable operatively controlled to (i) draw the moveable pulley toward a side of the structure, thereby increasing tension in the loop so that the load, suspended by the loop, moves away from the side of the structure and (ii) allow the moveable pulley to move away from the side of the structure, thereby decreasing tension in the loop so that the suspended load moves toward the side of the structure.