| 摘要 |
A fire escape includes a pair of wheels having upper and lower wheels, two looping cables fitted with plurality of transverse rods tensioned by the two wheels and also fitted with plurality of platforms extending from partial transverse rods and a gear box driven by the upper wheel and designed to increase the rotation speed by several gear sets in the gear box wherein the first gear set of the gear box is fixed with a driving disc outside the gear box to be preliminarily slackened the rotation speed by a frictional clamping collar disposed around the inner driving disc and the third gear set of the gear box is fixed with a rotating arm which is pivotedly connected with two crank levers each terminated with a centrifugal block to thereby extend the centrifugal block to frictionally contact the inside wall of a drum casing to further slacken the rotation speed of the upper wheel and slow down the descending speed of platform when loaded by weight for safer escape. |
