US255715A - Roller grinding-mill - Google Patents

Description

(No Model.) 3 Sheets-'Sheet l; R. BIRKHOLZ.

ROLLER GRINDING MILL. No. 255,715. Patented Mar. 28,1882.

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ROLLER @BINDING MILL.r i N0. 255,715. l `PaZGIlB. Mar. 28.1882.

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UNITED STATES PATENT OFFICE.

RICHARD BIRKHOLZ, OF MILWAUKEE, WISCONSIN.

ROLLER GRlNDlNG-MILL.

SPECIFICATION forming part of Letters Patent No. 255,715, dated March 28, 1882.

Application filed Decc1nber1, 1861.

To all whom z't may concern Be it known that I, RICHARD BIEKHoLz, of Milwaukee, in the county of Milwaukee and State of Wisconsin, have invented certain Improvements in Roller Grinding-Mills, of which the following is a specication.

My invention relates to improvements designed more particularly for use in small or portable mills, although certain of the features are applicable to mills of large size.

The principal object of theinvention is to produce a mill which shall be exceedingly cheap and simple in construction, in which the accurate adjustment ofthe rolls may be maintained without the useof separate adjustable devices for their opposite ends, and in which the press- -ure applied between the rolls shall be governed automatically by the hardness of the material passing between them.

.It also has as anobject the production of d nr- 4 able and accurate ribbed rolls without incurring the expense of cutting the ribs-thereon,`

-as is now commonly practiced.

The invention consists in the combination of a standard, a hopper-frame mounted in bearings on the standard, and a movable roll mountedin und sustained by said frame; in the combination, with the above, of a spring applied to urge the hopper downward; also, in the combination, with the above-named parts, of a stop device limiting the swinging action of the hopper; also, in various minor details, which will be hereinafter described.

Referring to the accompanying drawings, Figure 1 represents a side elevation of my improved mill; Fig 2, a rear elevation ofthe same; Fig. 3, a vertical central section'of the same on the line a: x, Fig. 2; Fig. 4, a trans` verse vertical section on the line y y, Fig. 3 Fig. 5, a horizontal section on the line .a z, Figs. 1, 2, &c.;Figs. 6, 7, and S, detail sectional views, illustrating thelconstructiou of the roller-bearings.

Referring to the drawings, A represents an uprighttubular standard designed to sustain the weight of the entire mill, provided with an enlarged or flanged base and having its upper end divided into two upright parallel arms, a.

B represents a horizontal shaft mounted `in fixed bearings orboXes in the arms a of the receive a supply of grain.

(No model.)

vided with a hand-crank or handle," by means of which motion is communicated to the machine. When the machine is to be driven`by power from an engine or other motor the shalt l B may be provided, in place of or in addition to the balance-wheel D, with a driving-pulley to receive a belt or with a driving gear-wheel. 1

E representsa horizontal bolt passed transversely through the upper ends of the standard-arms a above the grinding-roll C, and serving as a support for the hopper body or casing F, which is pivoted and free to swing upward and downward in a vertical are to a limited extent thereon. The casing F ismade of suitable form and size to completely inclose the two grinding-rolls, being adapted to fit closely against their sidel or end faces, and being fashioned at the top into a small hopper or throat, c, throughwhich the grain is delivered between the rolls, and being also fash ioned at its lower ends beneath the rolls into a meal-receiving chamber provided with an of the rolls and securedtogether by means of transverse bolts c, as clearly represented in the drawings. In order to permit the swinging motion of the casing, its sides are slotted at the points where the stationary shaft B' passes through thesamc, as indicated in Fig. 5 and in dotted lines in Fig. 3. To the upper part or mouth of the casing F a large wooden hopper, Gr, is bolted or otherwise H represents a second horizontal shaft carrying at its middle the second grinding-roll, I, and mounted at its ends in bearings or boxes tired rigidly in 'the sides of 'the casing F, as plainly represented. It will be seen that the second roll, I, and its ,shaftarethus supported by the surrounding casing F, and that as the casing swings upon the bolt E from a point above the first grinding-roll the downward movement of the casing serves to crowd the rolls toward eachother, while on the' other secured to -parts being slipped endwise over the journals IOO hand its upward motion serves to separate them, the movable roll I swinging around a point eccentric to the stationary roll. Motion is communicated from the shaft of the stationary roll C by means of a small outside pinion, J, through a large gear-wheel, K, to

ythe shaft of the second or movable roll, I.

Under the arrangement shown it will be seen that the weightof the easing, the second roll and its'V shaft, the hopper, the material containedin the hopper, the strain ofthe gears, and the strain which the roll C may exert through the intermediate material upon the roll I all tend to urge the casing downward, and thus crowd the rolls toward each other. It will be readily seen, therefore, that in grinding hard substances which offer a great resistance to the movement of the rolls the movable roll is crowded downward with greater pressure than when grinding soft material, and that consequently the rolls are urged together with increased force. This action of the rolls in .crowding one toward the other is in a great measure dependent upon the fact that the two rol-ls are driven positively at different surface speeds, the result being that the material e11- tering between the two rolls and offering aresistance'to their rotation tends to lock them together in such manner that the rotation of V the stationary rolls tends to turn the movable rolls and the support downward. Owing to this action it will be seen that the mill is in a ydegree automatic or self-adjusting as regards the pressure applied to force the rolls together, vthe rolls being crowded together with agreater 'force when grinding hard material than when able manner; but I prefer, as shown in the drawings, to pivot to the lower end ofthe casing a bolt, J, passing transversely through the standard A, and bearingon its rearend a nut, l, and a washer acted upon by a spiral spring,

Je, seated within the standard around the bolt,

as plainly represented in Figs. 8 and 4. By adjusting the nut the tension of the spring may be increased and the pressure between the rolls augmented to any extent required.y

- vIn place of the nut, any other suitable device may be employed as a means of adjusting the spring.

-The device represented in the drawings con- '.sists simply ofa screw, M, inserted through the standard A, and arranged to encounter a lug or stud on the under side of the hopperframe. In order to prevent the screwM from beingjarred out of adjustment by the vibration of themill, the jam-nut N is applied, as shown inthe drawings.

In practice I find the most convenient receptacle for the chop or grist to be an ordinary sack, and in order to holdsuch receptacle in position beneath the delivery-spout d, I connect to the standard by a bolt, o, a horizontal ring. P, provided on the inside with a series of small upturned hooks or teeth, m, adapted to engage with the edge of the bag and to sustain its mouth in an open position beneath the spout. In place of the teeth, any other fastening devices may be used.

Inasmuch as nails, stones, and other foreign matters ot' refractory'character are liable to tind their way into the mill and endanger breakage of the parts, the bolt E is constructed of such size and strength in relation to the other parts of the mill that it will give way before the other parts receive a dangerous strain. This breakage ofthe bolt will permit the hopper-frame to fall t'o a limited extent and throw the movable roll away from the roll C,

thus avoidingthe danger of serious injury to Y the mill. When the breakage of the parts occurs thehopper-framewillbe sustained and prevented from falling bythe shaft ot' the roll B.

The roll shafts orjournals may bc mounted in boxes or bearings of any suitable construction; but it is desirable that these boxes shall be adjustable to compensate for wear-that they should be readily removable in order that they may be replaced by others when badly worn. I prefer to make use of cylindrical bearings or boxes, such as represented in Figs. 4 and 5, each bearing R consisting merely ot' a tube or sleeve slipped around the shaft closely into a seat in the side of the support, and secured by means of a set-screw, S, tapped into the support, and bearing at the inner end in a groove encircling the box or bearing. The bearings of the movable roll are supported in the hopper-frame, and the bearings of the stationary roll mounted in the arms of the standard A.

In order to afford the long and solid support for the boxes orbearin gs, the support is provided with outside hubs or bosses to receive them, as plainly represented. By making the boxes of cylindrical form and inserting them in the manner described, their read yv rotation at will is permitted, so that the wear may be equalized upon their inner surfaces. Instead, however, of seating the boxes or bearings of the stationary roll D in bosses formed upon the support, as above described, the parts may be constructed as shown in Figs. 6 and 7, in which it will be seen that the boxes are seated in recesses in one side of the standard-arms a, and secured therein by clamp-plates T, fastened by bolts. By loosening the bolts the rotation or removal ot' the box is permitted. This arrangement also permits the introduction of thin sheet metal at any point outside of the IOO IIO

box, thus permitting the box `and shaft to be A accurately adj usted, as required. This feature will be found of great value and convenience :in the event of the parts being j arred. slightly out of line, as frequently occurs in practice.

In order to keep the bearings properly lubricated, I cast upon the outside of the casing and the standard, respectively, oil-reservoirs U, and insert a wick from said reservoir inward to the respeetivejournal, as plainly represented in Fig. 6, suitable holes being cored, ot' course, for the admission of the wick.

In the course ot' a long experience in the 0peration of roller-mills I have found it extremely difticult to insure an exact parallelism of the axes of the two rolls. In mills as at present p constructed it is, I believe, the universal practice to construct rolls of a length usually several times as great as their diameters. This construction necessitates the application of separate adjusting devices to the two ends of each roll. In practice it is found impossible to secure an exactly uniform adjustment of the pressure devices, and consequently much difficulty is experienced on account of the rolls grinding unequally at'the two ends, the mate-- rial being ground liner at one end than at the other. In order to overcome this difdculty, I construct my rolls ot` a length or breadth considerably less than their diameter, as plainly represented in the drawings, and supporting the two ends of each roll in one and the same casting. j The single support of the movable roll being arranged to move at right angles to the axis of the opposite roll, Iam enabled to maintain at all times, and by means of a single set of adjusting devices, an exact uniform space between the two rolls from end to end, under all adjustments and conditions.

Having thus described myninvention, what I claim is- 1. The combination of the standard, the roll mounted in fixed bearings in the standard, the hopper-frame pivoted to the standard, and the movable roll journaled in and supported by the hopper-frame, as described and shown, whereby a proper relation is maintained between the hopper and rolls and the weight of the hopper applied to aid in forcing the rolls together.`

2. The combination of thestandard, the roll roll, the swinging hopper-frame, a second roll sustained by the hopper-frame, and a stop device, substantially such as shown, to limit the swinging motion of the hopper-frame.

4. The combination ofthe standard, the roll mounted in xed bearings therein, the hopper` supporting frame having a pivotal connection with the standard, the second roll sustained by the hopper-frame, the spring tending to swing the hopper-frame downward, and an adjustable device, substantially as shown, to limit the movement of the hopper under the action ot' the spring.

5. In combination with the standard, the stationary roll mounted therein, and the movable roll, the swinging hopper frame or casing adapted to inclose the two rolls and pivoted to the standard at a point above the axes ot' the rolls.

6. The combination of the forked standard, the roller-casing pivoted to and within said standard, and the two grinding-rolls mounted within the casing and supported one by the standard and the other by the casing, substantially as described and shown.

7. -In combination with the grinding-roll mounted in fixed bearings, the second roll mounted in a support which swings from the center above the axis of the stationary roll, and pinions connecting the two rolls, as shown,

whereby motion is imparted from the first roll to the second and the strain of the drivingpinion caused to assist in urging the movable roll downward.

8. The combination of the standard, the tixed roll, the movable roll, the swinging roll-supporting frame encircling the shaft of the sta tionary roll, and the frame-supporting bolt E, proportioned in relation to the other parts to break or give way when the mill is subjected to excessive strain.

RICHARD BIRKHOLZ.

i Witnesses:

J. E. WILDIsH, ERICH WESTERNHAGEN.

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