Lifting mechanism with counterweight - adjusts amount of counterweight movement dependent on load

摘要

The lifting mechanism has a counterweight coupled to the hoist mechanism via a variable-ratio transmission system (4,5,8). The latter is adjusted dependent on the load (1), a heavier load causing more movement of the counterweight (3), typically in proportion to their respective weights. The hoist mechanism can have a load sensor controlling the transmission ratio. The transmission system can comprise a gearbox, or a steplessly-adjustable unit with link belt.