Patent ID: 7258325

Claim:
A system for selectively vertically translating a plurality of loads relative to a structure, comprising: (a) a plurality of lift assemblies connected to the structure, each lift assembly including a rotatable drum translating along an axis of rotation, at least one cable extending from the drum, a drive motor connected to the drum and a controller connected to the drive motor for selectively regulating rotation of the drum, the controller in communication with a corresponding controller in each remaining lift assembly and configured to control at least two of (i) a rotational velocity of the drum in a first rotational direction; (ii) a second rotational velocity of the drum in a different second rotational direction; (iii) an acceleration of drum rotation in the first rotational direction, (iv) a second acceleration of the drum in the second rotational direction, (v) a first amount of drum rotation in the first rotational direction, (vi) a second amount of drum rotation in the second rotational direction, and (vii) drum rotation corresponding to a drum rotation in another lift assembly.