US2510970A - Radial disk mill with cooperating ribbed plates - Google Patents

Description

M. E. GINAVEN 2,510,970 RADIAL DISK MILL WITH COQPERATING RIBBED PLATES June 13, 1950 Filed March 20, 1947 v Filer/e5! Patented June 13, 1950 RADIAL DISK MILL WITH COOPERATING RIBBED PLATES Marvin E. Ginaven, Springfield, Ohio, assignor to The Bauer Bros. Company, Springfield, Ohio, a

corporation of Ohio Application March 20, 1947, Serial No. 735,922

2 Claims.

This invention pertains to grinding mills and more particularly to a special form of an attrition type mill.

The present mill is of the attrition type, but i not intended for, nor does it accomplish the customary function of such mills, namely the grinding of grains or other friable materials into a floury meal. By comparison with the usual attrition type mill, the present mill produces a relatively granular product with a very low percentage of fines. A further distinction and advantage of a mill of the present type over the usual attrition mill is that it may be used to decorticate seeds such as cotton seed or cereals, such as oats, without unduly fracturing the meat or pulverizing the cells thereof.

Thus one of the principal objects of the present invention is to improve the construction as well as the means and mode of operation of plate type mills, whereby they will not only be more eflficient in use, and of greater capacity, but easier to maintain and unlikely to get out of repair.

A further object of the invention is the provision of a plate mill of the attrition type, which is capable of use as a comminuting mill.

A further object of the invention is to provide a plate type mill which may be easily adjusted to produce a finished product of different grades.

A further object of the invention is to provide a plate type mill in which the reduction of the material is accomplished by engagement with the periphery of the plates rather than with the lateral faces thereof.

A further object of the invention is to provide a plate type mill of the kind described having the advantageous structural features, the inherent meritorious characteristics and the mode of operation herein described.

With the above primary and other incidental objects in view as will more fully appear in the specification, the invention intended to be protected by Letters Patent consists of the features of construction, the parts and combinations thereof, and the mode of operation, or their equivalents, as hereinafter described or illustrated in the accompanying drawing.

In the drawing, wherein is shown the preferred, but not necessarily the only form of embodiment thereof,

Fig. l is a fragmentary side view, in section, of a mill of the present design.

Fig. 2 is an enlarged detail View showing the relation of the two cooperating plates.

Fig. 3 is a fragmentary perspective view of one of the mill plates.

Fig. 4 is a fragmentary perspective view of the other mill plate with which the plate of Fig. 3 cooperates.

Like parts are indicated by similar characters of reference throughout the several views.

Referring to the drawing, i represents the end bell of a motor housing, the motor being secured to a suitable base or pedestal at 2. The motor 1 serves as the mounting means for the mill, the grinding plates and housing therefor being secured to the motor shaft-and motor housing respectively.

Supported upon the motor shaft 3 in outwardly spaced relation with the bearing 4--is a carrier disc 5 to which one of the pair of grindin plates is secured. Located intermediate the bearing 4 and disc 5 is a bearing seal assembly 6 of a conventional type.

The mill housing I is secured to the end of the motor housing I, and provides therewithin a, milling chamber 8. Located upon the outer wall 9 of the mill housing is hopper l0 through which material to be treated is fed to the millin chamher. The lower wall ll of the hopper I0 is inclined so as to direct the material to be treated into the milling chamber through the entrance l2 which is substantially aligned with the axis of the motor shaft 3.

Located within the chamber 8 is a pair of grinding or milling plates l3 and i4. Plate I3 is secured to the outer wall 9 of the housing, and is therefore a non-rotating plate in the mill shown. For differing types of work however, the plate l3 may be made to rotate without departing from the principle involved in the present disclosure. The cooperating plate I4 is secured to the rotating carrier disc 5, and rotates relative to the plate I3, whether the plate l3 be stationarily or rotatively mounted. Mounted concentrically with the plate l4 upon the carrier disc 5 is a supplemental disc l5 which completes the central surface of the plate l4, permitting grain or other material to flow over the entire surface without obstruction.

Around the periphery of plate [3 are arranged a plurality of equally spaced upstanding triangular studs or teeth I 6 as is best seen in Fig. 4. The number of studs I6 may vary widely, depending upon the type of product desired. The spacing between the studs may also be varied which change likewise causes a change in the finished product. Plates having 32 to 64 studs have been satisfactorily used. By using a greater number of relatively narrow studs, the percentage of open area intermediate the studs may be increased, which increases the capacity of the mill,

1 and at the same time produces fewer fines in the finished product.

The studs K5 are arranged with their broad faces inwardly, which surface I! is arcuate in concentric relation with the center of the plate I3. This inner surface H, in addition to its curvature, is slightly beveled or inclined outwardly, as best seen in Figs. 1 and 2. The altitude of the triangular stud is therefore less at the outer extremity [8 than at the inner extremity adjacent the plate [3.

The cooperating rotary plate it has a series of radially arranged ribs l9 and 2E) thereon, as is best shown in Fig. 3. The alternate ribs are somewhat longer than the ribs 19, and extend substantially to the inner edge of the plate I 4. Both the ribs l9 and 20 have enlarged flaring terminal portions at their outer ends. Both ribs are also tapered or inclined from the inner to the outer ends thereof, the outer ends being of substantially he same height as the studs l6 upon the mating plate 53. The terminal sur faces 2! of the ribs are convex, their arcs being concentric with the center of the plate. The surfaces 2! are also slightly beveled or tapered inwardly to substantially the same degree as the studs E5 on the plate IS. The relation of the studs i5 and the ribs Ii -20 best seen in Figs. 1 and 2.

When the plates 13 and M- are secured to their operating position as shown in Fig. l, the sUrfaces 2! of the ribs l92D are parallel or concentric with the surfaces i1 on the studs is, but are located ii slightly spaced relation therewith. The relative spacing of the ribs i920 and the studs [6 may be varied for the efiicient processing of different materials, or tc produce a milled product of varying degrees of coarseness. The diagonal or tapered surfaces H and 2! permit easy adjustment of the clearance therebetween, by movement of the plates l3-M toward or away from one another when setting up the mill. This may be accomplished by the use of shims intermediate the plates i3i:i and their respective supports or by increasing or decreasin the thickness of the pads 22 23 on the backs of the plates i3--! l. Such adjustment of the plates not only varies the clearance 24 intermediate the surfaces i! and 2! of the cooperating members, but also alters the clearances 25 and 2%: intermediate the lawral extremities of the studs and the adjacent surface of the cooperatin plate It and the lateral extremities of the ribs ee-ee and the adjacent surface of the cooperating plate l3. Clearances of up to A have been satisfactorily used for the clearance opening 24. This spacing has been varied downwardly for different materials, and may also be increased if desired.

The motor I is a variable speed motor and means are provided for controlling the speed thereof since the relative speeds of rotation of the plates i3-i4, whether both are rotating or one is stationary, has a controlling influence upon the grade of material produced by the mill.

In operation, the material to be operated upon is fed from the hopper I!) through the opening 12 into the milling chamber 8. Entering the chamber 8 at substantially the center thereof, the material is picked up by the ribs l9--20 on the rotating plate l4, and moved outwardly on the plate intermediate the ribs by centrifugal influence. The material is thereby carried past the inner surfaces I! of the studs it under pressure of centrifugal force. As the material intermediate the ribs l920 comes in registry with the openings intermediate the studs l6, such material partially enters this space under the centrifugal influence to which it is subjected. It is then broken by the edge of the ribs l92il in cooperation with the edge of the studs [8. The terminal portion of the material being broken away from the body thereof, it is then discharged. The remainder of the material is carried on to succeeding openings intermediate the studs I6 where the same action takes place until the material will completely pass from the plate I4 into the openings intermediate the studs IS.

The edges of the studs Hi and the ribs l920 cooperate to break or tear the material therebetween, but do not necessarily cut the material. There actually is no cutting action in the present mill, since for best. results the plates are so adjusted that sufficient clearance is provided that a cutting action is impossible. Such adjustment increases the capacity of a mill in which the material is cut by the use of rotary knives, or closely rotating ribs.

One of the distinctive features of the present mill, is that all processing of the material takes place about the peripheries of the discs Iii-i4 intermediate the studs 55 and ribs 19-20. Such action is quite different than that of the usual attrition mill wherein the grindin or reduction of the material is effected between the lateral faces of the discs by means of cutting blades or ribs thereon. The present mill with its peripheral breaking action materially reduces, in fact practically eliminates the production of objectionable fines in the processed material. The material is not subjected to excessive pressure since the material is subject only to the influence of centrifugal force. This minimum of pressure, combined with the spaced operating surfaces on the tWo cooperating plates results in minimized pulverizing of the material processed. Not only is the objectionable pulverizing minimized or eliminated, but the cape-.0. y of the mill is greatly increased since the material is completely processed to the desired state although passing through the milling chamber much more rapidly than in the conventional attrition mills. Maintenance cost of the present mill is much less than in the conventional mills since the plates do not run at close tolerances and there is therefore much less abrasion thereon. Censequently the plates have a much longer net-- ural life, reducing the need for replacement and adjustment.

The material passing between the studs I6 is discharged into the annular chamber 21 intermediate the peripheries of the plates l3l4 and the housing 1 from which it is discharged through the conduit 28 into an appropriate receiver which is not shown.

In lieu of using shims intermediate the plates l3-l4 and their respective supports for adjusting the relative spacing of the plates, such adjustment may be accomplished by longitudinal movement of the rotor shaft 3 relative to the housing. The spacing intermediate the bearing 5 and the housing 1 permits such movement of the shaft in one direction, while the spacing intermediate the bearing and the seal assembly 5 permits movement of the shaft in the opposite direction. The shaft 3 is maintained in adjusted position by means of a locking device on the outward end thereof, which is not shown. This method of adjustment greatly facilitates the changing of the mill for the grinding of different materials, or the production of varying grades of material and does not necessitate disassembly of the mill.

From the above description it will be apparent that there is thus provided a device of the character described possessing the particular features of advantage before enumerated as desirable, but which obviously is susceptible of modification in its form, proportions, detail construction and arrangement of parts without departing from the principle involved or sacrificing any of its advantages.

While in order to comply with the statute the invention has been described in language more or less specific as to structural features, it is to be understood that the invention is not limited to the specific features shown, but that the means and construction herein disclosed comprise the preferred form of several modes of putting the invention into effect, and the invention is therefore claimed in any of its forms or modifications within the legitimate and valid scope of the appended claims.

Having thus described my invention, I claim:

1. An attrition mill of the type wherein material to be processed is centrally introduced into a milling chamber containing a pair of relatively rotating milling plates, characterized by a pair of vertically mounted relatively rotatable annular plates, an annular mount for one of said plates through the central opening of which the material is introduced into the milling chamber, a mounting disc for the other of said annular plates against the surface of which the material is discharged into the milling chamber, a plurality of radially disposed laterally projecting tapered ribs carried by the disc mounted plate in alternate relation with a plurality of relatively short radially disposed laterally projecting tapered ribs also carried by the disc mounted plate, all of said ribs terminating in a common are concentric with said plate and in spaced relation with the periphery thereof, transversely flared arcuate terminals on said ribs, the arcuate surface of which is concentric with the center of said plate, said arcuate terminal surface being tapered inwardly relative to the periphery of said plate, a plurality of substantially triangular shaped laterally projecting studs carried adjacent the periphery of the other plate in overhanging relation relative to the laterally projecting ribs of the disc mounted plate, an arcuate base on said triangular studs concentric with the center of the plate, said arcuate base being tapered outwardly relative to the periphery 01' said plate, said plates being laterally adjustable relative to each other to thereby vary the clearance intermediate the adjacent arcuate surfaces of the studs and ribs, the construction and arrangement being such that the material to be processed is fed from the center of the milling chamber outwardly into engagement with the terminal faces of the ribs and the studs by centrifugal influence, the processing being accomplished at the periphery of the plates, and the condition of the processed material being determined by the relative spacing of said plates and the associated studs and the ribs.

2. An attrition mill of the type wherein material to be processed is introduced intermediate a pair of milling plates and ultimately discharged therefrom, characterized by a pair of relatively rotatable milling plates, means for introducing material to be processed at the center thereof, a plurality of radially extending ribs on one of said plates by means of which material to be processed is moved radially relative to said plates by centrifugal influence, said ribs terminating in spaced relation with the periphery of said plate, a plurality of laterally projecting studs on the other plate of said pair overhanging the terminals of said ribs, said studs being located in radially spaced relation with the terminal faces of the aforementioned ribs and occupying the space intermediate the terminals of said ribs and the periphery of the first mentioned plate, the adjacent cooperating surfaces of said studs and ribs being arcuate in concentric relation with the center of said plates, opposite tapers on said overlapping suri'aces of the studs and ribs, said plates being axially adjustable to vary the clearance intermediate the studs and ribs, and means for varying the relative speed of rotation of said plates, the construction and arrangement being such that the material is engaged by the cooperating faces of said studs and ribs and the processing thereof takes place about the periphery of said plates under pressure of centrifugal influence.

MARVIN E. GINAVEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 143,336 Cutler Sept. 30, 1873 462,277 Peer Nov. 3, 1891 812,122 Fassett Feb. 6, 1906 1,281,829 Plaisted Oct. 15, 1918 1,595,282 Bauer Aug. 10, 1926 1,608,717 Bell Nov. 30, 1926 1,755,037 Tamen Apr. 15, 1930 2,004,737 Tonks June 11, 1935 2,321,599 Hofmann June 15, 1943 FOREIGN PATENTS Number Country Date 14,016 Great Britain Aug. 10, 1889 25,444 Great Britain May 2, 1912 342,507 Great Britain Feb. 5, 1931

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