US1114339A - Grinding-plate for mills. - Google Patents

Description

I. G BRYANT.

GRINDING PLATE FOR MILLS.

APPLICATION FILED JAILIB, 1912.

1,1 14,339. Patented 001;. 20, 1914.

- 2 SHEETS-8HEETL J. G. BRYANT.

GRINDING PLATE FOB MILLS. APPLICATION FILED JALIB, 1912v 1,1 14,339. Patented Oct. 20, 1914.

2 SHEETS-SHEET 2.

NORRIS PETERS 00-. PNOID-LITHU. IASHINGTOIYV. D. C.

" JAMES s. BnYANrQo r roar-Horton, MICHIGAN;

GRINDING-PLATE "Fort Mints.

To all whom it may concern Be it known that LJAMns G. BRYANT, a citizen of the United States, residing at Port Huron, inthe county of St. Clair and State of Michigan, have invented new and V useful Improvements in Grinding-Plates for Mills, of which the following ,is a speci fication. j 1

This invention re'latesto grinding mills, and has for its object to provide an efficient form of grindingvplate adapted to accomplish the comminutionof materials withja minimum liability of overheating, and which will insure performance of the grinding function uniformly throughoutfthe area of the plate. That is to say, it is an object to avoid, in a mill employing oppositely rotat- 111g grinding disks, action upon the 'entlre stock introduced therebetween immediately adjacent the eye or inner portions of the I disks, whereby tendency to overheat is engendered as well as a waste of power incurred. 1 I

It is therefore arelated object to provide such a" construction of plates that certain quantities of grain or other material shall be conducted to outer portions of the disks or plates before being acted upon, while yet insuring accomplishment of the grinding operation upon other portions of material throughout the area of the plate. While accomplishing these ends it is desired at the same time'to avoid excessive radial, movement of disintegrated material under the action of centrifugal force, and the opposite extreme of lagging or circular movement, whereby material. would tend to'be held between the grinding plates longer than neces-- sary. j

In many prior devices havlng means to prevent grain from moving toward the periphery of the grinding elements too i I rapidly to be properly acted upon, the rebody of stock would beacted upon initially tarding elements have been of such form as to cause instant grinding or cutting of the material engaged thereby,"whereby the'main within a limited portion of the plates; and

it is a most 'im'portantiobject of this invention to effect retardation without involving grinding of the whole stock engaged by the retarding elements. the radial speed of the stock is however not so much sought, as the accomplishment of initial treatment thereof over a wide area of the plate. It is not therefore desired to say that retardation is essential as the action,

Specification of LettersPatentL t Patented Och Application filed January 18, 1912 Serial No. 672,005 I period.

The actual controlfof" may be accomplished "with comparative cause the prior attempts toward the same end have usually involved the retardation rapidity and yet thoroughly. The term re-" tardation is employed as vbest calculated to};

T 0 convey the. idea of the function sought, be-I of the stock: from radial movement as exi emplified in the patent to Davis, #827,059,

JulypZQth, 1 906,and also familiar the dressing of-millstonesl for a considerable An important object to provide an efiicient distributing means for feeding ma terial evenly to all portions" of the space between theplates.

Other obj ects and advantages will beap-v parent from the following description and p p j fromthe drawings, in which,

Figure'l is a segmental view of one of my plates, Fig, 2 is a similar view of a modification, "Figldis a section on the line 3-3vof Fig, 1, Fig. l isasimilar View. on theline 44: of Fig. 2, Fig. 5 is a fragmentary plan of a modified construction. 7 p I There is illustrated a disk 10in Figs. 1 and. 3, slightly reduced in thickness toward the center, whereby an enlarged throat 11 is provided adjacent the eye 12, when two plates arein operative position. The plate is intended to rotate in a given direction, indicated by the large arrowin Fig.1" and the elements to be described may be considered as having each a front .or forward side in the direction of rotation and arear side opposite. The plate comprises a breast 5 portion 13 having ribs 1& arranged with a view to the distribution of stock to the waist portion 15 immediately outward there of. The ribs lj are arranged in groups ex tending at a'tangent to the axis ofthe disk, the ribs of each group being graduated in length, the shorter ones beinglocatedon the forward side of the group whioh toward 5 the'direction of rotation of the disk. The 'j inner ends of the ribs are arranged on a line diverging inwardly from the, adjacent long rib at the rear side of the immediately adjacent group, whereby the bays, 16am formed, allowing ready access of stock to I the spaces between all ofthe ribs and avoidi I ing choking ofthethroa-t. i i

If desired, the breast and'cwaist portion may be made in two' separate parts, as shown" in Fig. 2, and may be rotated at difierentiated speeds, this being the preferable construction, the movements beingin. the d1reotions indicated bythe arrows; j I I outer one laterally thereof in the direction approximately in a radial direction, and these series at the. forwardsides of the The waist is provided with segmental groups 17' of short cutting and leading bars 18 in alined parallel series, bounded'by the annular skirt bar 19. Certain series of alined bars in each group, preferably those adjacent the rear side of the group, extend groupsbeingparallel to the inner ohesbecome slightly tangential. in direction and are made shorter in length. The groups are arranged in as narrow a form aspossible to. avoid too great a tangent in any of the bars. Each of the cutter bars is connected at-its outer end tothe inner end of the next ofrotation, by connecting or grinding bars 20, which are thus inclined from their inner ends toward their outer ends in the direction of movement of theplate; Zig-zag ribs are thusformed .having between them a series the waist have the innermost. bar 18 omitted,-

thus providing broad channel heads 21, and as the grinding bars 20 of the remaining inner cutter bars pro ect but part way across this-channel, this leaves an outer throat 24:.

It should be noted that while the inclined sides of the grinding bars 20' extend across the channels 21 inwardly thereof, by reason of the corresponding direction of the H channels themselves, areduced clearance provided through which stock may pass out wardly should an exeess've amount tend to accumulate before the grinding bars. The forward sides of the bars 18 are approximately vertieahalthou'gh this angle may be varied as found. desirable, and at their rear sides they may be inclined outwardly toward theirfbases, or not, as found best. The rear sides of the grinding bars 20 may corre spend in form to thoseof the bars 18. vThe bar all have broad flat upper surfaces or lands 25, upon which a certain amount of grinding action occurs, as distinguished from the cutting action occurring because of the formation of the bar edges. The grinding action occurs particularly over the grinding bars, the sloping sidesof which tween the lands of the opposed plates, no matter how small the particles. It is desirthe breast.

cutter bars, the grinding bars and the skirt able that a fillet be formed at the bases of those sides of all the bars which rise abruptly from the plate, whereby tendency of the channels'to clog is lessened, as well as the liability of the bars to break off from the plate reduced.

It should be noted that the tangent of the bars ll of the breast is such as to deliver the the bars 18 short, the frequency of the grinding bars is increased, and bythe use of a proper runner plate, pulverization may be attained;

j i The plates are adapted to be formed with similar faces on each side, so that each side may be used, and may be made in sections to be clamped or otherwise secured to carrying base members. These details are'not illustrated, being mechanical expedients familiar in theart.

. The ceiperating. plate to be superposed over the one just described, may be similar, or otherwise formed. There is illustrated in Fig. 5 a slight modification of the described form, in which the connecting grind ing bars between the cutter bars extend rearwardly and thereby avoid drawing stock in-' wardly when coacting \Vltll' the grinding bars of an opposite plate constructed as 7 shown in the preceding figures.

In'use, the stock, fed to the eye 12in the customary way, is admitted in large quantities, because of the wide space between the plates, and the small number of ribs thereadjacent, and israpidly admitted to the grooves or channels between the ribs 14: of

By these ribs the stock is. roughly reduced and quickly delivered to the waist whereit is further out and ground by the bars 18 and 20. The channels between the ribs 14 allow the passage of the' stock smoothly, without packing or heating,

and the same is the case in the channels 21. cutting apart ofthe stock, lead a portion In these channels, the bars 18, in addition to outwardly against the bars 20'. It will be apparent that all of the stock delivered from the breast ribs will not be engaged and lifted by the first grinding bar slopes encountered if there is a very large quantity, and as there is a clear space forwardly thereofa portion I of the roughly broken stock may reach the serve to raise particles into engagement be.

grinding bars. There are at least two channels thus to be reachedby the material passing the first slope without being engaged.

The inclination of the forward face of the grinding bars j is such that even a. slngle grain or portion of other material reaching it Wlll tend to move upwardly thereover to 1 be ground immediately; but when there is a largeiquantityof material tending to become packed in passing over the bar 20, there is a free lateral escape for the stockwhich will quickly relieve the press and leadthe" stock without undue friction to the succeeding grinding elements where it may have its constituents treated without clogging, or the heating which might be attendant on too great a quantity of material being acted uponwithin a limited space. At the secondfset of slopes the same relief may be had, and

some of the stock allowed to third slopes direct.

It is of special importance to consider the pass to the effect of forming. the cutter bars and grind;

ing bars with their slopes or lifting surfaces in a continuous rib. The lifting of the stock into engagement between disks is made most certain, by reason of the fact that the stock itself tends to become inert; and whether it does or not, it is impelled in the direction of rotation of the disk in the groove of which it lies by the rear side of the groove bearing thereagainst, or against intervenlng'stock. As the stock moves outwardly along the channels and encounters 1n .place of the abruptly extended side of the cutter bar the inclined surface of the grinding bar, it is most certain to rise thereon or be lifted thereby. Thus the liability of dog ging, choking, or packing is much less than it would be if the raising of the stock were dependent entirely upon its inertia of mo tion radially or the pressure of following stock thereon. Both the factor of radial movement of the stock and that of lateral pressure of the sides of the groove thereagainst impelling the stock in a circular direction, are utilized to; lift the material from the bottom of the groove in this device.

What is claimed is: 1. A grinding plate for mills having a stock groove including a plurality of portions adapted for movement of stock therein toward the periphery, and alternate connecting groove portions between those first men tioned and disposed obliquely thereto, the

connecting portions having sloping rear lift stock there sides adapted to engage and on, for the purpose described... 2. A grindin plate having a peripheral skirt bar, and otlier inner bars formed thereon of tortuous shape and spaced to form continuous channels for the 'fiow of stock from the center to the skirt, the inner bars including leading parts and baffle portions Copies of this patent may be obtained for extending obliquely thereto, the baflie' porv tions having sloped sides to'engagexstock from an inner channel portion, for the purpose described.

3. A grinding plateyhaving a skirt bar and inner bars, the majority of the bars each comprising a series 'of sections spaced laterally of each other in one direction and spaced 4 from each other radially of theaxis of Totation of the plate, and connectingportions having sloped sides disposedin the direction of rotation of the plate and channels extend, ing continuouslybetween all the bars from the skirt inwardly. i

I 4. -A grinding plate having bars each comprising a series of sections spaced laterally of each other 1I1 OI16 directlon and spaced from each. other radially of the axis of rotaforming cutting edges in combination with an opposed-plate havingsimilar bars, the

tion of the plate, and connecting bar por tions having sloping sides in one direction and abrupt sides in the opposite direction 3 connecting bar portions of whichhave op positelyarranged sloping sidesand cutting edges.

5. A grinding plate having bars compris ing in combinationiaterally and radially ingstock from the channels of which said bars form the sides.

6. A. grinding platecomprising in combination a disk, bars thereoncomprising series of parallel radially spaced cutter bar sections, certain of the'series having their innermost sectlons om1ttecl-,Tand alternated series. of parallel dlagonalconnecting bar portions] connecting adjacent inner and outer. ends of cutter bars in series spaced laterally in one direction, ,the sides of the connectingbar portions 1n," the direction of rotation being sloped for engagement with stock flowing outwardly between inner cutter bardsections for lifting of aportion thereof, and adapted also to allovx lateral escape of'a portionof stock without grind ing when tending to pack or clog the passages between the bars.

my handin presence of two subscribing witnesses. Y

lVitnesses: I

JOHN C. GRAHAM, JOHN L. 'BLAGK.

five-cents e t 'y add es ing t e C mmi ioner o l tent 'w h In testimony whereof I have hereuntoset I JAMES o. B YANT.

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