The Mechanical Handling and Storing of Material

320 THE MECHANICAL HANDLING OF MATERIAL which serves to connect the loose sheave and fall-block g with the trolley. When the skip is on the ground, the surface ab of the part t, which is movable on the pin f, rests on the guides cd, which are attached to a and b, so that the pin h of the block G can catch in the recess b. If ab is resting on cd, the pawl l no longer rests on the point e, but will engage with the catch x on the rail rope (see Fig. 457), holding the Fig. 457. Showing Action of Calhoun Cableway. trolley at the point g. As soon as the load has been raised, and h has thus engaged with b, the shield t revolves to the left round the pivot F, while the pawl l, which is controlled by springs, will be arrested at the point e, and the hook M releases the catch x, so that the horizontal movement of the trolley can commence. The throw- off apparatus v is shown in Fig. 457, and consists essentially of the levers i, k, m. The running trolley strikes against the lever i, and at the same time the lever k engages Fig. 458. Travelling Trolley used on Fig. 459. Skip or Shovel Bucket the Calhoun Cableway. used on Calhoun Cable way. the hook h on the skip or shovel bucket (see Fig. 459), and thus effects the discharge of the same. On the return journey the pawl l comes in contact with the tripper z, which disengages L from the point e, whereby the fall-block G is disengaged from the trolley, and the skip dropped through the upward movement of the shield T. Fig. 460 shows a larger view of the tripper z. It may be noted throughout that all shocks are borne by the hauling rope and not by the rail rope.