摘要 |
An emergency drive system for elevators allows manual raising and lowering of the elevator in an emergency condition when an emergency brake has been applied to a rotating member of the elevator drive system. A linkage element is pivotally mounted to the brake, and carries a manual drive member having a drag bearing and a pair of guide rollers. A drive line passes about the drive member, guide rollers and a hand crank. Operation of the hand crank creates a tensional imbalance in the drive line, pivots the linkage member to engage the manual drive member with the rotary member. The increased drag to crank rotation resulting from the engagement causes the linkage element to pivot about the manual drive member, backing the brake away from the rotating member and allowing the rotating member to be turned by the manual drive member. The device is self-regulating, permitting only sufficient release of the brake to cause a slow rotation of the rotating member and the elevator car motion. <IMAGE> <IMAGE>
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