KTOM, Crusher (Fig. 1) is a modification of the Blake. The motion of the mov able jaw is imparted in the usual manner, by eccentric, pitman, and toggles. The machine is strengthened by longitudinal tie-bolts, through the frame, which re ceive all the strain due to crushing the rock or ore. In the toggle abutment, through which the main tie-bolts pass, are recesses around the bolt holes, which are covered with wrought-iron washers of such strength that they will not bend under the ordinary strain in crushing the ore, but will yield to excessive strain. The movable jaw is pivoted at its lower end in stead of at the top, as in the Blake crusher, this method of hanging the jaw giving a product of more uniform size, and givinT, the least motion at the point of greatest strain. The die and shoe, or the crushing faces of the jaws, are smooth, being made of bars of good steel, of proper size, laid horizontally. Thin strips of metal are provided to put behind the bars to keep the wearing faces in line. The toggles are made with rolling ends with the object of reducing friction. The ends are made with three teeth, which mesh with the toggle-seats, the toggles being thus held in place.
The Fulton Crusher is constructed upon the same principle as the Blake, with modifica tions which it is claimed render the wearing parts more accessible and more easily renewed. The stationary jaw is held in place by flat iron bars, having eyes forged on their ends, slip ping over shafts in the top a-nd bottom of the jaw. By taking out pins in the ends of the upper shaft, and loosening the nuts holding the upper flat iron bars at the back of the rock breaker, the latter can be slipped off the upper jaw-shaft. and the jaw, pivoting on the lower shaft, can be opened and lowered, making it easy to replace the shoe, die, and cheek plates. A spring is placed beneath the loose babbitt-lined gib, bearing against the lower part of the eccentric of the pitman-shaft, taking up lost motion and preventing heating and pounding. The tension of the spring is regulated by a wedge, placed beneath it, and ad
3usted by means of nuts on the outside of the pitman. The shoes and dies are composed of alternate layers of wrought-iron and hardened machine-steel bars placed horizontally on edge, and held together by a heavy wrought-iron band shrunk around them. The iron being softer than the steel, wears away more rapidly, causing the shoe and die in a short time to present a corrugated surface to the rock, and giving a better crushing effect. The surfaces of the iron bars wear but a short distance below those of the steel, being protected by the latter. The crushing of the rock upsets the iron bars and thus tends to force them more firmly within the band.
The Buchanan Crueller '2) is constructed upon the same principle as the Blake.
The essential point of difference is in the method of supporting the movable jaw, B. In the Blake this swings on a shaft passing through its top ; in the Buchanan the jaw, which has a long, horizontal pro jection ander the pitman, U, is supported by two rocking arms, F, pivoted at their lower ends upon the base of the breaker. Conse quently, every part of the jaw moves evenly back and forth. There is no other strain on the rocking arms than the weight of the jaw, which the makers claim is an advantage, as there is no direct strain due to crushing im posed on pivotal pins or shafts, as in other breakers of this type.
The Brennan, Crusher (Fig. 3), which is much used for breaking rock for macadam, is a modifica tion of the Blake crusher, differ ing mainly in the fact that the driving-shaft is placed near the base of the frame instead of at the top. The pitman and tog gles, consequently, work above the eccentric instead of below it. In the base of the machine is an oil-chamber, 0—the oil being kept at uniform height by means of supply and overflow pipes— in which the ec centric work s, thus insuring a constant. and am ple lubrication of this important wearing part.