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The type of quarry equipment most commonly used in conjunction with this crusher is the three-sided steel skip, carried on a flat-top truck or flat car. These skips are provided with a shackle on the rear end, which is engaged by a hook actuated by a small hoist. This apparatus slides the skip over against the lip of the receiving hopper, and tilts it to discharge its contents. The skips discharge over a feed-roll which retards the flow of material so that the entire load does not drop into the crushing chamber at once. When the skip is empty it is pulled back on to the truck or car by a counterweight attached to the opposite end of the same cable which performs the hoisting operation.
We have mentioned the heavily ribbed hopper which surmounts the frame and extends up to the level of the feed roll. This hopper serves the double purpose of directing the material into the crushing zone, and preventing stones thrown by the slugger teeth from flying out of the crusher. It is also necessary to cover the top of the hopper with heavy netting to contain flying spalls.
The straight-sided, rectangular hopper construction and the violent agitation in the crushing chamber, tend to minimize blocking and bridging in this crusher. When bridges do occur they are difficult-and dangerous-to break while the rolls are running. |
