The Mechanical Handling and Storing of Material

4oS THE MECHANICAL HANDLING OF MATERIAL The following table gives dimensions, weights, and capacities of the Hone grab Size. Dimensions of Grab when Closed. Approximate Weight of Grab. Capacity, in Cubic Feet. Rate of Discharge in Tons of Coal per Hour with Ordinary Steam Crane at about 40 ft. lift. Ft. In. Ft. In. Cwt. No. 1 3 6 by 3 6 13 15 20 „ 2 4 0 ,, 3 6 14 18 24 ,, 3 4 0 „ 4 0 17 23 29 „ 4 4 0 „ 4 6 21 30 37 >> 5 5 0 ,, 4 0 22 35 43 ,, 6 5 0 ,, 4 6 24 39 45 ,, 7 5 0 „ 5 0 29 44 50 „ 8 6 0 ,, 6 0 48 78 72 At the Becton Station of the Gas Light and Coke Co., the collier “ Eleanor,” having a cargo of 2,/50 tons of coal, was discharged in sixteen and a half hours by three No. 7 Hone grabs, manipulated by hydraulic cranes. ligs. 57i and 578. Bleichert Grab Built on the Hone Principle. The Bleichert Grab.—Another single-chain grab is illustrated in Figs. 577 and 578. This is built on the “Hone” principle by Messrs Adolf Bleichert & Co., of Leipzig. The action is as follows :— In the closed position the two short outer chains kk are wound round the spindle a, whilst the inner chain m hangs loosely in the interior, or lies on the, top of the material contained in the grab. The movable portion b is held in position by pawl c. The drum is held by the two pawls dd and the ratchet segments which form part of the drum. In order to discharge the load the two levers ll are made to touch an obstruction which is suspended from the head of the crane, and is adjustable up or down. As this is in a fixed position, when the grab is being lifted the levers ll are forcing down, by means of two short chains, the pawls dd. The drum d, which is fixed to the spindle a, is compelled to revolve through the weight of the grab and its load, so that the two small chains kk unwind from the spindle a, whilst the hitherto slack chain m winds itself on to