| 摘要 |
A motor for controlling the elevating and lowering of a load comprises a storage drum, an output drum and a spring member operatively connected therebetween to provide a spring motor therewith, and a pair of cord drums aligned with and respectively adjacent the storage drum and the output drum. A gear train including an idler gear associated with the storage drum drivingly interengages the cord drums with the output drum, whereby the elevating and lowering of a load attached to the cords on the cord drums is balanced regardless of whether the elevating or lowering force is applied centrally between the points of attachment of the cords to the load. |
