US2517990A - Rotor for hammer mills - Google Patents

Description

Aug. 8, 1950 M. N. DRESSEL ROTOR FOR HAMMER MILLS 2 Sheets-Sheet 1 In uenlor Filed June 5, 1946 Aug. 8, 1950 M'. N. DRESSEL ROTOR FOR HAMMER MILLS 2 Sheets-Sheet 2 Filed June 5, 1946 I u ventor Merle M fifessel,

Patented Aug. 8, 1950 7' lVjIerle N; ll Jressel, Cloud,- Minn assignor of k v cneyhalftoplarence; A. Trossen, St., Cloud,

This invention relates a; hammermilland more particularly to an improved hammer mill of the type disclosed in my prior patent, No. 2,013,378, issued September "3,v 1935.

. The primary object of the invention is to pulverize'and reduce material toQa desired fine,- ness.

Another object istb entitle the same device to bev employed for producing various grain sizes .0f the pulverized materiaL; ay;

The above and other objects may be:attained by employing this invention which embodies :among its features a vertically disposed convolute drum having a peripheraldischarge opening.. and an inlet opening in at least .one side wallnear the center thereof, a shaft nounted in saidvdrum to rotate about a horizontal axis,a circular cylinidrical screen removably mounted in said; drum :iccncentric with the shaft, arms radiating; from ithe shaft in the screen and blades pivotfidto the armsfor cooperation with-the screen in :pulver-izing material introduced; into $11 3 ildrum t ou h h i et p nin hsaid s ,r so 1 operating with the drum casing in creating an air-blast through the discharge opening whereby the pulverized material will be ejected from the drum.

Other features include providing the drum with an air intake opening in the side opposite the inlet opening through which the material is introduced, means to regulate the amount of air entering the drum through the air intake opening, and a hopper to feed the material to the drum through the inlet opening.

In the drawings:

Figure 1 is a side view of a hammer mill em bodying the features of this invention,

Figure 2 is a vertical sectional view taken substantially along the line 2--2 of Figure 1,

Figure 3 is a vertical sectional view taken substantially along the line 33 of Figure 2,

Figure 4 is an enlarged fragmentary sectional view taken substantially along the line 4-4 of Figure 2, and

Figure 5 is a fragmentary elevational view, parts being shown in vertical section, illustrating the relation between the pivoted and fixed blades.

Referring to the drawings in detail, my improved hammer mill designated generally IIl comprises substantially square side plates II and I2 held in spaced parallel relation by a convolute wall I3 having a peripheral discharge opening communicating with a discharge duct I4 arranged between the walls II and I2, and extending upwardly as illustrated in Figure 3. The side Fwall II is provided 1w h a journal bearing IS .which aligns with a journal bearing I6 carried by the; side wall I2 and in .vvhichthefshaft to be more fully hereinafter, describedis mounted to'rotate. Formed in theside wall II adjacent the journal ,bearingjIE is an inlet opening I; l

through which;;the material ;tobe pulverized is introduced, into the, interior of the drum 10, A

valved ina manner to be'more fully hereinafter explained. b I 5 g m -Attachedito the Wall 1.2 above the ope i is an angle bracket 20 supporting avvertically .mova ble,;; externally screw 1 threaded; jqshaft" 2 I carrying a nut 22 by means of which the shaft :2] may be-adjusted vertically. I Attachedtothe lower end of the shaft and: riding in suitable guides 23 carried anther-wall I2 adjacent oppo- .site ends of the opening 1 His a plate 24 by means .of which the area of the opening ;-I 9 may be lv if i .1. "-31 Mountedin the bearings I5 and I 6 to rotate about a horizontal axis is a drive shaft 25 which is formed between the bearings I5 and It with an area 26 of hexagonal cross section. Driven onto opposite ends of the hexagonal area 26 are hubs 21 carrying adjacent their outer ends flanges 28, and fixed to the hubs 2'! and flanges 28 are radial arms 29 carrying adjacent their outer ends pivots 30. Pivotally supported on the pivots 30 are blades 3| which are adapted to cooperate with the screen to be more fully hereinafter described in reducing and pulverizing the material introduced into the interior of the drum. Fixed between each pair of arms 29 is a radial blade 32 and carried on the outer side of each arm 29 is a radially extending knife 33 having an outwardly disposed inclined sharpened edge 34. These knives serve to cut fibrous material introduced into the device and prevent its collection between the arms 29 and the walls II and I2, while the radial blades 32 not only serve to create a blast of air through the device but also to prevent the lodging of fibrous material in the space between the arms 29 and the consequent clogging of the machine.

The screen previously referred to is designated generally 35 and comprises a cylindrical foraminous member 36 concentrically disposed with relation to the shaft 25 within the drum I0, and in close proximity to the extreme outer edges of the blades 3|. Carried by the foraminous body removably secured to the wall l2 iby spaced.

screws 39.

In operation, it will be "understood that the material is introduced into the drum from the hopper [8 through the passage or inlet opening l1 and the shaft 25 rotated in its bearingszll5 and I6. The centrifugal force created by the rotation of the arms 29 and blades 3| will cause the blades to tend to move against the material into a radial position, thus forcibly driving the material against the screen 35 80 as to hammer the material until it attains a fineness which will permit at to pass through the foraminous wall 33 and into the passage formed between the convo'lute wall IQ of the drum and the screen. The rapid rotation of the blades 3| alsoserves to :create a vgiraft-of air through the opening I 9 to the interi'or-of the drum and thence'out through the discharge passage l4. Ihe blast of air thus created is ladened with the pulverized material which writers the passage through the screen -35 and in this manner the pulverized material is also "discharged through the passage M from whence it maybe delivered for storage or packaging and shipment.

From the foregoing it will be obvious that I'not only utilize the centrifugal'force of the blades -3l to pulverize the material introduced into the drum, but also these blades serve in the capacity of the impellers of-a blower so as to pick up the pulverized material and discharge it from the device. Obviously screens 35 of varying degrees of fineness may be employed and by the simple expedient of removing the bolts from the ears 3! it is apparent that the screen readily may be changed.

While in the foregoing there has been shown and described the preferred embodiment of this invention it is to be understood that minor changes in the details of construction, combination, and arrangement tof' parts may ,be resorted to without departing from the spirit and'scope of the invention as claimed.

I claim:

:In a hammer mill, a rotor comprising a 1'0- tatable shaft, circumferentially spaced pairs of longitudinally spaced arms on said shaft, blades 'pivotally connected to each pair of arms, laterally extending blades carried by each of said arms disposed :beneath said pivoted blades and inclined outwardly and radially from the axis of rotation, and radial blades fixedly secured to and disposed between each pair of arms beneath said pivoted blades.

N. DRESSER REFERENCES CITED The, following references are of record in, .the file of this patent:

HNI'BED STA E TE Number Name Date 144,330 Gardner Nov. 4,187.8 6'795046 De --Camp- July 23 1 901 557,969 S'choe'llhorn Apr. 19, 1904 "845}1'71 "Gardner 26;, 11907 908301 .Ponsar Jan. 5, -l 909 1,572,722 Jacobson Feb. 9, 1926 '-1 ,647,'1-83" *Leggemann Nov. 1, 1-927 1,758,702 Jacobson May 13, 1930 ,8012842 Briggs Apr. 21, 1951 "1,861,779 I 'Born'hauser June I l- 932 1,934,180 Fischer Nov. 7', E933 2,026,426 Matejci k Dec. -3-1, I935 2 ,"289197 Miller Apr. 22, 1941 22415667 lvlari'lcoif' May 13;, 1 941

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