19,424. Fairweather, W., [Brown Hoisting Machinery Co.]. Sept. 26. Grabs.-Relates to single-chain grabs with block and pulley operating - mechanism, and comprises means for automatically effecting the opening and closing of the grab. Fig. 1 shows the general arrangement of the grab and Fig. 4 the construction of the catch devices &c. The bucket is made up of an exterior frame H, having a rail or track- L, secured to the bottom, upon which are hung sliding blocks b pivotally connected by arms p to coupling-pieces a, sliding vertically along guides g in the frame. Each coupling-piece a has an upward extension n which is provided with a shoulder n<1>, and is pivoted in its seat by a pin v. The lower block C, carrying the sheaves M, is semicylindrical in shape, and is provided with a pair of catch-devices each consisting of an upright spring-pressed plunger P, operating a pair of toggle-like levers l, t, adapted to withdraw the catch W from engagement with the shoulder n<1>. The lower part of th'e catch W is connected with the lever l by a bell-crank lever e and link f. The two plungers P are connected by links to ensure equal motion. When the grab is opened to gather up a load, the block G and the coupling-pieces a are at the bottom of their travel, and the catches W are in engagement with the shoulders n. The rope R is then hoisted and the grab closes, the parts C, a rising until the stops d<1> are engaged. The load is then raised and traversed to the dumping point, where a hanging rope engages the dumping-lever A', thereby pressing the studs A and operating the plungers. The catches W are thus disengaged and the bucket opens by its own weight, the coupling-piece a sliding down the guides g. Tumblers t<1> prevent these coupling- pieces from rising again until the block C is lowered and the catches W engaged against the shoulders n<1>. In this arrangement, the weight of the bucket. is always taken by the rope R, but in a modification, shown in Figs. 7 and 12, the bucket is arranged to hang directly from the trolley during traversing. To prevent the bucket from opening when its weight is taken off the rope R, a hook h is provided hinged to the upper part of the croupling- piece a. When the bucket is closed, this hook engages a catch-piece F<1>, having one or more crossshelves F<2>, and connected to the supporting-arms B<1> by a pin v<1> which slides in a vertical slot in the frame. When the weight of the bucket is transferred to the arms B', the catch-piece F<1> slides vertically until one of the cross-shelves F<2> engages the hook h. A guard-rod k prevents the hook from becoming accidentally disengaged.