tance between jaws 4 and 5. Securely attached to this platform is the engine D, capable of being reversed by any of the wellknown methods, and the furnace and boiler E, and also, preferably, a water-tank, G.<a href="http://www.crushing-plant.com/solutions/bauxite-processing-machine.html">Bauxite Processing Machine</a>. The platform is supported upon two pairs of flanged wheels, 9, connected by the ordinary axle, resting on rails 10 by means of trucks H, springs I, and boxes K in the manner usual with single-wheel trucks, and is provided with a brake, L. The driving-axle M of the engine operates a driving-pulley, N, made heavy, so as to operate as a balance-wheel. A belt, R, on this wheel passes over the pulley-wheel P, which operates the crusher, the wheel P being fixed on the same shaft as the balance-wheel Q of the crusher.
The device for tightening the pulley-belt R consists of the upright frame S, in which slides a frame, T, whose edges are beveled so as to fit under corresponding beveled edges in the upright frame S, and is thereby prevented from leaving the latter. Attached to frame T are the idlers V, between which runs the belt R, as shown. The frame T is elevated or depressed by a rod,V, attached to the bottom of said frame and sliding through a stud upon the upper portion of frame S. A set-screw, a, in this stud screws against rod W and regulates its vertical position,<a href="http://www.crushing-plant.com/solutions/belt-conveyor.html">Belt Conveyor</a>. The device for accorninodatin g the tension of the pulley-belt to the vertical springing or jolting of the car is applied as follows: The rod V is cut, and the lower end of the upper half, I), of said rod is fastened to a sleeve, (1, and provided on either side with a longitudinal slot, in each of which slots plays a stud, e, the studs being opposite each other and fastened to the head of the upper end of the lower half of said rod, as shown in Fig.
At each end of the sleeve d, and between each shoulder and the stud e, is a spring, g, so that there are two springs upon the same sleeve. The arrangement of these springs, as will be seen, allows the frame T and the idlers to give either up or down, ac cording to the joltin g of the car.The opening or hopper it between the jaws of the crusher opens down upon an inclined sifter or screen, 7', provided with openings of any desired form, preferablylongitudinal slots, as shown, of such size or width as to allow of the passage through them of dust, dirt, &c., and fine particles of stone, but to not admit the larger pieces of stone.