US248292A - Grinding-mill - Google Patents

Description

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0. U. GRANDALL.

GRINDING MILL.

No. 248,292. Patented 001;. 18, 1881.

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WITNESSES:

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v C. I]. GRANDALL.

GRINDING MILL.

No. 248,292. Patented 001;.18, 1881.

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- GYPRIAN U. ORANDALL, OF STERLING, ILLINOIS.

GRINDING-MILL.

SPECIFICATION forming part of Letters Patent No. 248,292, dated October 18, 1881.

Application filed April 22, 1881. (ModeL) To all whom it may concern Be it known that I, CYPRIAN U. URANDALL,

a citizen of the United States, residing at Sterling,.in the county of Whitesides and State of Illinois, have invented certain new and useful Improvements in Grinding Mills; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters or figures of reference marked thereon, which form a part of this specification.

My invention has reference to certain improvements in grinding-mills; and it consists in the features hereinafter mentioned.

The object of my invention is to furnish, in

adoublg mill, a divider which shall unerringly lower halves of the jacket; Fig. 5, a central transverse vertical section through the machine.

A is the bench supporting the mill.

B is a frame, placed on the bench Av to support the hopper and screening apparatus.

0 is an ordinary-hopper, into which the grain to be ground is placed.

D is a screen,which atits upper end is placed under and receives the grain from the hopper O, and at its lower end is supported adj ustably by means of the strap a, passing from the sides of the screen through the roller 1). By twisting the roller b the lower end of the screen D is raised and lowered at will. The upper end of the screen D is pivoted in any suitable manner, and its lower end vibrates laterally. Such motion is imparted to the screen D by means of an arm, 0, pivpted at one end on the side and near the lower end of the screen D, the other end of the arm 0 being pivoted to the upper end of the oscillating lever 07, which latter is pivoted near its center on the cross-beam e,

ing corrugated surfaces, and being placed suf-,

ficiently near each other to crack or partially grind the grain as the latter passes downward between the two adjacent sides of such rollers.

The roller E is revolved by pulley or cog-wheel affixed to one end of its axle, and can be turned 1 by hand or run by a horse or other power. The rollers are revolved toward each other at their tops by means of the small cog-wheelsg g. I find by experiment that the grinding is done more rapidly when one of the rollers is run at a higher rate of speed than the other, and I have therefore varied the diameter of the engaging cog-wheels g 9, so that the roller F may run at a greater velocity than the roller E. 1,.

G is a divider, having the duplex, corrugated, and elliptically-concaved faces h h, which refeed the preliminarily-cracked grain against thelowerpartof the grinding-rollers EF. The

grinding-faces h h of the divider G are concaved elliptically rather than circularly, and by means of such peculiar conformation the faces h h gradually approach the grindingrollers from the feed to the discharge end, thus greatly accelerating the grinding process. I

make the center crown of the divider G flat, and wide enough to retain quite an amount of meal, and utilize the meal accumulating thereon in diverting the partially-ground grain under the respective grinding-rollers, because I find, in view of the fact that one roller takes feed faster than the other, that no mechanical device will form so true a center between the rollers E F as the falling meal itself. The divider G is provided with lateral tenons r r,

centrally located, which fit into corresponding recesses ss in the lower sides of the jacket H, and thus hold the divider from end movement. In each recess 8, and over the tenon r, I place the spring t, which serves to hold the divider down to its point of adjustment.

The divider G is supported by the table I,

having the four inclined bases t i t 1', each of which latter rests upon a shelf, j, cast on the inner side of the lower part of the jacket H, such. shelves having an inclined upper surface.

By means of the screw-bolt K the table I is drawn or pushed down on the shelves j, and thus the divider G is raised or lowered so as to grind coarse or fine, as may be desired.

On the inner surface of the upper half of the jacket H, and at the ends of the rollers E F, are formed the annular recesses 70 k, which receive the ends of the rollers E F and permit the inner face of the jacket H to project over the ends of the rollers E F, and thus prevent the passage of any partly-ground meal between the ends of the rollers E F and the inner faces of the jacket H, where, in the ordinary horizontal roller, it is apt to collect and pack and heat. The sides ofthe upper part of the jacket H are contracted to give the recesses k k depth. This permits the grain to spread the width of the grinding-rollers without crowding around the ends.

As the lower halfof the r0llers,when running at as high rate of speed as it is necessary to run. these small rollers, are apt to carry up part of the meal behind the ends of the rollers, to prevent this, and also to provide a ready exit for all meal working around the lower half of the ends of the rollers E F, I cut away the inner surface of thejacket H, opposite the lower h alf of the ends of such rollers, forming the outwardly-receding walls I l.

The operation of my mill is as follows: The grain placed in thehopperO passes down therefrom through the screen D, between the grinding-rollers E F. There the grain is preliminarily cracked or broken, the rollers not being set so close to each other as to grind into meal or flour. After this first process the material falls upon the flat crown of the divider G, where it soon accumulates into a ridge, down the respective sides of which the material passes to the grindin g concave faces h, in proportion to the rapidity of the grinding of the respective sides. The roller F, by reason of its greater velocity, disposes of and draws more material than the slower-revolving roller E; and as a metal ridge would be fixed and arbitrary, I substitute the ridge of meal, which causes the material to fall the fastest to that side on which there is the greatest exhaustion. As the feed ends of the grinding-faces of the divider Gr are set farther from the rollers than the discharge ends, the material passes into a narrow chamber as it is reduced in size, and the grinding is gradual over the whole of the faces h It. By turning the screw-bolt K the divider is set to or from the rollers. The meal is discharged outwardly from both sides of the divider, but is gathered by thejacket H into the discharge-spout at the bottom.

I deem the screen D of great importance. The grindingrollers are made of hard iron to avoid wear, and are therefore liable to have their corrugations broken by the interposition of any hard substance. In grinding corn often pieces of nails, small gravel, &c., are shoveled up. The screen D effectually prevents such, as well as silk and husks, from passing to the cylinders. The screen has also the functions of distributing the grain the full length of the grinding-face of the rollers.

What I claim as my invention. and desire to secure by Letters Patent of the United States,

1. The cylinders E F, in combination with the divider G, the latter being provided with a flat crown or truncated apex to serve as a bench to receive the falling meal, so that the latter may form its own line of division, substantially as and for the purpose mentioned.

2. The combination, with the rollers E F, of the divider Gr, having a flat crown or truncated apex, and duplex corrugated and ellipticallyconcaved faces h h, substantially as and for the purposes herein shown and described.

In testimony whereof I affix my signature in presence of two witnesses.

C. U. GRANDALL.

Witnesses:

JOHN W. NILEs, SYDNEY T. OSMER.

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