US1799435A - Grinding mill - Google Patents

Description

N. NELSON GRINDING MILL April 7, 1931.

Filed March 26, 1928 3 Sheets-Sheet 1 Jba/a J7 April 7, 1931. NELSON GRINDING MILL Filed March 26, 1928 3 Sheets-Sheet 2 N. NELSON GRINDING MILL April 7, 1931.

Filed March 26, 1928 3 Sheets-Sheet 5 72 1 762' j/JOT Patented Apr. .7, 1931 UNiTED STATES PATENT; OFFICE NICOLAY NELSON, OF WAUKEGAN, ILLINOIS, ASSIGNOR TO BLATCHFORD CALI MEAL COMPANY, OF WA'UKEGAN, ILLINOIS GRINDING MILL Application filed March 26, 1928. Serial No. 264,629.

This invention relates to mills for grinding grains, cereals, screenings, or other material which is adapted to be ground in IIllllS of the beater type.

5 The objects of this invention are to provide an improved mill which will be particularly eflicient in operation and which will require a comparatively small amount of power in proportion to its capacity; to provide a mill having different types of heaters arranged to coact with grinding surfaces; to provide a mill having fiat bar heaters and combined hammer or T beaters; to provide a novel ar-' rangement for mounting the heaters; to provide means for ventilation or circulation of air throughout the interior of the .mill; to provide adjustable air inlets to facilitate the grinding operation and also to clean certam portions of the mill; to prpvide a centrifugal mill of comparatively large diameter whereby it will operate effectively at a relatively low speed; to provide readily removable screen guideways; and to provide such other advantages-and novel features as will be described more fully hereinafter.

In the accompanying drawings illustrat ing'this invention;

Figure 1 is a side view with parts omitted or shown diagrammatically for convenience in illustration;

Figure 2 is a front view;

Figure 3 is an enlarged sectional side view taken on the line 3-3 of Figure 2;

Figure 4 is a cross sectional view taken on the line 44 of Figure 3; and

Figure 5 is adiagrammatic view or pro: jection illustrating the spacing and arrangement of the beater elements.

In order to make the mill comparatively light, and also sufliciently strong, I prefer to construct the body or casing of sheet steel and mount the same on a base formed of cast iron. As shown in the drawings, the base or bent plate 6 carries the casing which comprises a lower section 7 and an upper section 8 which is provided with a cover 9. The mill is preferably provided with a double feeding arrangement 10 whereby the material may be fed in at the outer periphery of the mill as indicated at 11 or through the sides as indicated at 12.

The bottom portion of the casing 7 is provided at either end with air intake open- 'ings 13 and 14 which are provided with adjustable slides 15 and 16 for regulating the same. The upper portion 8 of the casing is provided on either side adjacent to thecenter with one or more air intake openings 17 which are provided with adjustable covers 18 for re lating the same.

he cover or upper portion of the mill is provided with any suitable form of grinding surface or devices, as for instance the stationary beater bars or plates 19, as shown in Figure 3. The sides of the lower portion of the casing are provided with removable guide strips 20 having one or more slots 21 for receiving the screen 22. These guides project outwardly at one end of the machine and a cover plate 23 is provided which is held in position by a bolt 24. This arrangement pro-' vides means whereby the screen may be quickly inserted or removed and may be adjusted with respect to the beaters. The latter provision is desirable as the grinding capacity for some materials is increased or decreased by having the screen plate nearer to or farther away from the beaters. As the grooves in the screen guides are apt to become worn, they may be readily renewed by removing the guides and inserting new ones.

The heaters and mechanism which will now be described form one of the important parts of the present invention. The center shaft 25 which is mounted in suitable bearings (not shown) carries a hub 26 which is keyed or otherwise rigidly secured thereon. This hub 'ablyarranged on the hub in such manner that the openings through the various disks will be in alignment and will be in alignment with the holes through the flange 27. The disks'are held together and fastened to the flange 27 by bolts 31 and spreaders 32 adj acent to the hub and are also further held by bolts 33 and spreaders 34, which bolts pass through the outer edge of the. flange 27. The plates or disks 29 are provided around their outer periphery with holes 35 for receiving rods 36 for supporting the beaters. These rods may be conveniently held against longitudinal movement by collars 37 and set screws 38 which are interposed between adjacent disks, as shown in Figure 4. While any suitable beaters ma be utilizdQI prefer to use a combination o grinding beaters 39 and bar beaters 40, as shown particularly in Figures 3 and 5. The grinding heaters 39 may be of the type shown in my prior Patent No. 1,492,102 issued April 29, 1924, but in the present instance I provide sockets or holes 41 in the outer portions of the beaters forv receiving weights 42 of lead or the like, whereby the beaters may be readily and accurately balanced. These beaters are usually formed of cast steel and are likely to be of different weights and if they are not properly balanced are apt to set up undue strains in the machine on account of its high velocity.

The bar beaters 40 are carried on arms 43 which are pivoted on the rods 36.

' The particular arrangement of the beaters in the mill, which constitutes another important feature, is shown diagrammatically in Figure 5. Starting at the left of the figure it will'be seen that there are three grinding beaters 39 which are arranged in alignment transversely of the machine, all being mounted on one'of the rods 36. A single beater is mounted on the next rod and three beaters on the succeeding rod. A bar beater is then arranged between these beaters, and the next three beaters, and so on around the disks. I have found that articularly good results may be obtained y using four of the bar heaters and forty-four grinding beaters, arranged m the manner shown. The single grinding beaters are arranged on opposite sides, as indicated, so that each group of or the side openings 12 and will be rapidly gri ng beaters will practically cover the ent1re width of the mill, the single beaters covering the spaces between the beaters of the ad acent series.

When the mill is in operation, the materiah will be drawnin through the feed opening 11 ground and beaten by the action of the, rotatm'g members in conjunctionwith the stationary elements and will be discharged through the base which is provided with an'outlet 44. A suction fan may be provided at the outlet if desired. During the grinding operation air 'may be admitted through the holes 17 and on account of the high velocity of the-rotatmg members, the air will be drawn in throu h the holes 30 in the disks and may also pass t rough the holes 28 in the flange 27 and will be equally disiributed throughout the easing. This will facilitate the even distribution of the material across the entire width of the machine so that the grinding operation is performed in an equal manner by various elements throughout the machine, thereby providing a uniform grinding action as well as preventing undue wear on any point of the machine. It will also be noted that the bar beaters will tend to distribute the material across the inner face of the casing as well as tending to create a draft through the mill due to the centrifugal action therein.

By opening the slides 15 and 16, air may be permitted to enter in the bottom of the casing, thereby tending to prevent the accumulation of dust or feed in the bottom of the mill and also ending to keep the screen clean.

As indicating'the relative proportions of the machine, the outside diameter of the heaters is about forty inches and the machine approximately 12 inches wide. On account of the comparatively large diameter this machine when run at the relatively low speed of eighteen hundred revolutions per minute will have a large capacity, and it may be directly driven by an electric motor, thereby avoiding the necessity of being keyed or belted for increasing the speed.

It will of course be apparent that the arrangement of the heaters may be varied for different materials and the proportions and.

construction of the machine may be modified for different purposes; therefore I do not wish to be limited to the exact arrangement herein shown and described, except as specifled in the following claims, in which I claim:

1. In a device of the character set forth, the combination of a shaft, a plurality of disks carried by said shaft, grinding beaters mounted on said disks, and bar beaters mounted on the disks intermediate of the grinding heaters.

2. In a grindin mill, the combination of a casing, a shaft t rough said casing, a plurality of disks mounted on said shaft, arms pivotally mounted on said disks, bars secured to the outer ends of the arms and extending substantially across the casing, and .grinding beaters pivotally mounted on the disks between the bar beaters, said grinding beaters having serrated outer faces and substantially T-shaped in cross section the head portions thereof extending only a portion of the distance across the casing, substantially as described.

3.'A grinding mill having a rotor provided with a plurality of T-shaped grinding heaters, and a plurality of bar beaters interposed betweensets of the grinding beaters.

4. A rotating element for grinding mills having spaces around the periphery thereof, a plurality of substantially T.-shaped hammer beaters, and a plurality of bar beaters, said hammer beaters being arranged in groups, some being in staggered relation with the others, and the bar beaters being arranged between the groups of hammer beaters.

5. The combination with a hub, of a plurality of disks secured thereto, rods extending through said disks, collars and set screws for holding the rods against longitudinal movement, and beaters pivotally mounted on said rods.

6. A grinding mill comprising a casing having a substantially rectangular bottom portion and a semi-circular upper portion, a

semi-circular screen mounted in the bottom portion, said upper portion being provided with internal grinding means, a shaft passing through said casing, disks secured to said shaft and having passages therethrough, beaters pivotally mounted on said disks, adjustable air openings in said casing adjacent to the shaft and adapted to permit air to enter and pass through said disks, and adjustable air openings in the lower portion of the casing below the screen,

7. In a grinding mill, the combination of a casing, a shaft through said casing, adjustable air openings in the sides of the casing adjacent to the shaft, a hub mounted on the shaft and extending substantially the full width of the casing and having an outwardly extending flange with relatively large openings therethrough to permit free circulation of the air, discs fitting closely over the hub and having relatively large air openings which register with the openings in said flange, means for spacing the discs longitudinally of the hub, bolts passing throu h said discs and flange and beaters carried by said'discs.

8. In a mill of the character set forth, the combination of a casing 'havin a feed mlet adjacent to the periphe and aving a bottom discharge, a shaft t rough said casing, air intake openings in the side of the casing ad acent to the shaft,.adjustable slides for said openings, a hub secured to said shaft and having an outwardly projecting flange with entering through said openings to circulateair passageways therethrough, a plurality of discs fitting over said hub and having air passages therethrough, means for securin the discs to the flange and heaters carrie by said discs, said air 0 enings through the discs and flange being a apted to permit air freely to the center of the caslng.

9. In a grinding mill, a rotor comprising a shaft having a plurality of spaced hammer supporting plates thereon, circumferentially spaced hammer car 'ng rods mounted in said plates, groups 0 hammers arranged on certain of said rods, stirrup hammers mounted on other rods and arranged betweer groups of the first mentioned hammers, eacl of said stirrup hammers spanning a pluralit j of the hammer supporting plates.

NICOLAY NELSON.

Images