Hoist for raising and lowering scenes on stage - has support plates on ceiling joists with elongated winch drum connected by universal joints

摘要

The hoist has support plates (20) secured to the joists (24) of a ceiling, and an elongated winch drum (10) made up of several sections (10'), interconnected by universal joints and supported by the plates. Each section has over part of its length a helical groove (18) on which a cable (12) for supporting the load is wound. Each support carries bearing wheels (28) engaging the helical grooves for rotatably supporting the winch drum and for causing its axial displacement at each turn by a distance equal to the pitch of the cable wound or unwound from the winch drum. The load will not be laterally shifted when being raised or lowered. A reversible hydraulic motor (34) is secured to an end of the winch drum so that the motor moves with the winch drum in its axial movement.