| 摘要 |
PURPOSE:To improve a retightening effect as well as to make an emergency escape easy by energizing a block divided into circular arcs in the diametral expansion direction and connecting them together via an elastic body, encircling a winding shaft to be possible to contact or separate, while winding a rope on the block and connecting the roped end to a retightener. CONSTITUTION:A gear 18 is clamped to a winding shaft 2 being solidly rotated together with a spool whose one end is engaged with a belt. A tooth part 21 engageable with the gear 18 is formed in an inner circumferential part of the block 20 divided into plural pieces, while the divided blocks 20 are connected to one another in the diametral expansion direction by a spring 23, and usually the tooth part 21 and the gear 18 are not engaged with each other. A rope 24 is rolled on the circumference of the divided blocks 20, the one end is connected to a retightener and the other end is set to a free end where load is applied. When the retightener works and thereby the rope 24 is pulled when something is wrong, the block 20 is diametrally contacted, engaged with the winding shaft 2 and rotated so that a tightening effect is brought into full play at once. When a movement of the rope 24 is stopped, the block 20 is diametrally expanded again by the spring 23 so that belt delivery is facilitated. |
