US2293667A - Attrition mill or disintegrator - Google Patents

Description

Aug. 18, 1942. T. D. sHANKEl. 2,293,667

ATTRITION MILL QR D ISINTEGRATOR Filed Feb. 19, 1940 A 5MP/fw' PatentedY Aug. 18, 1942 UNITED STATES PATENT oFFIcE ATTRITION MILL R DISINTEGRATOR rllimothy D. Shankel, Bristol, Tenn. Application February 19, 1940, Serial No. 319,797

4 Claims.

This invention relates to improvements in an attrition mill or disintegrator for reducing middling stock in flour mills to flour and particularly to reducing the finer middlings and flakes in their last reduction in the process of milling whereby a closer yield and softer, whiter flour is produced.

More specifically the invention relates to the construction of a disintegrator head with a revolving disk so constructed and arranged that exact and desirable adjustment may be had, thus reducing the grinding friction, giving a more even grind of the material, with less power consumption than is possible of structures of a similar type.

One of the objects of the invention is to provide a disintegrator head of such a construction that a choking of the stock is substantialy eliminated or materially minimized whereby production with the use of the device is increased.

.Another object of the invention is to provide a disintegrator head with an adjustable structure that can be so regulated that the our part of the middling is reduced to a finer state while the bran part of the stock is not broken up as finely as with other types of devices utilized for the same purpose.

- Another object of the invention is to provide a structure for the purpose specified in which direct grinding action is eliminated.

A still further object is to provide a device for the purpose specified in the form of an attachment which will fit the conventional Buckley middling mill as an attachment without material changes or alterations.

Other objects will more clearly hereinafter appear by reference to the accompanying drawing forming a part of the specification and wherein like characters of reference designate corresponding parts throughout the several views in which:

Fig. 1 is a vertical section view.

Fig. 2 is an end elevational.

Fig. 3 is an enlarged section showing the revolving grinding disk.

The present assembly includes a base A and standards B and C, the former being the supporting element for the mill structure and the latter being the frame element for supporting with a central opening D through which the drive shaft d extends. A hopper F is provided at the inlet end through which material is fed to the mill and this material is moved forward by means of the feed screw or auger G mounted on the enclosed end of the shaft d. The screw feed G terminates inward of the flange e providing a chamber g between the same and the adjacent face of the disintegrator or attrition structure hereinafter mentioned. A pulley I-I is mounted on the end of the shaft d outward of the support C for connection with a suitable source of power. Any driving means may be utilized which is convenient and suitable for the work to be accomplished. Secured to the front flange e of the mill housing E is the disintegrator casing which, includes front wall J, the connecting inner wall 7', and side walls 7". The inner or connecting wall, 7 is formed with an opening K at a point in axial alignment with the screw feed G. The portion; of the wall i which defines the opening K ccn-y stitutes a portion of one of the walls forming the chamber y at the end of the feed screw G. The face of the wall :i which faces the end of the screw feed G is beveled at an oblique angle, as shown at lc. This bevelled face lc and the chamber g form in connection with the attrition disk L the main features of the structure. The attrition disk L is mounted to freely rotate with the shaft l, the latter rotating in the hub portion l' against the thrust bearing M. The inner race m is supported on the reduced extremity of the shaft Z and cooperates with the race m to provide for the mounting of the balls therebetween as shown. The outer race bears against the transverse bar N which latter provides the adjustable backing element for the thrust action of the rod l carrying the disk L. The thrust bar N is mounted on the spaced fixed pins O, the inner ends of which o are threaded into the outer wall J of the mill structure. The thrust bar N against which the bearing M operates is formed with spaced openings through which the fixed pins O extend. The outer end of the pins. O are threaded to receive the adjusting wheelsy P which by virtue of the compression springs p exert an adjusting thrust on the bar N and thus, against the grinding disk L whereby this grinding disk L is adjusted with respect to the adjacent face of the inner wall 7" of the disintegrator hous` ing. The upper end of the disintegrator casing, defined by the walls J, i and :1" is provided with an opening and a suitable closure cap Q to permit access to the interior thereof.

Y The feed augerG is arranged for longitudinal.

sliding adjustment within the cylindrical casing E and with the shaft d, whereby the Width of the compartment y may be regulated in a manner to obtain a desirable feeding of the material and regulated disintegration is obtained. The adjustment of the auger G is obtained by means of the set collar R, the latter being slidably arranged on the shaft d and secured with relation thereto and with respect to the bearing r by means of the usual set screw r as illustrated. Instead of the auger G being fixed to the shaft d and adjusted through the sliding movement of the shaft in its bearings, as shown and described, the auger might be arranged to slide on the shaft and in this manner regulate the size of theattrition chamber g.

In the operation of the apparatus forming the subject-matter of the present invention the auger G is first set in the feed cylinder E' to space the same properly with respect to the wall :i whereby the size of the chamber g is properly determined for use with the type of auger andA its R. P. M. This adjustment is made by means of the set collar R slidably arranged on the shaft d and cooperating with the shaft .bearing r atgthe upper end of the standard G. The adjustment of the auger to provide the chamber g is of utmost importance. The auger is normally driven at approximately 400 R. P. M. and forces the stock into the small chamber g at the left end of the feed cylinder E. The rotation of the auger further causes the stock to be carried around in the same direction it is turning and this in turn causes the disk L to revolve inY the same direction and with the stock. The relative rotation of the disk L with respect to the R..P. M. of the auger is determined by the adjustment of the hand Wheels P-P, the best results being obtainedV by driving the auger at a speed approximately ten times faster than the R. P. M. of the disk L. The width of the chamber g is such as to prevent any direct grinding action of the material. Instead, the stock is forced into the small attrition chamber g and is turned by theauger, The stock adjacent the auger is carried around rapidly due to the rotation of the auger while the stock next to the head is being carried around proportionately much slower. Consequently the stock is disintegrated into very ne flour which passes out between the disk L and the adjacent wall. The thrust on the disk L is transmitted. to the shaft l and thence to the thrust bearing M, and associated parts t the adjacent Wheels' P-P. The rotary action imparted to the disk L and its curved face both function to keep a constant discharge through the opening and prevents clogging of the disintegrated stock. This clear'- ance -between the disk L and they adjacent wall y", as previously stated, is regulated by the hand wheels P-P and determines the flneness to which the stock is to be disintegrated or reduced before passing out into the opening. It will be noted that the working face of the disk L is slightly rounded and this rounded face of the disk and the bevelled inner face of the feed opening K are essential to a successful fricticnalgrinding action of the material and discharge thereof as above set forth.

It will thus be seen that the adjustment of the auger G with its drive shaft will determine the sizeof the chamber g, This adjustment is proportional to the size and R. P. M. of the auger. The disintegration of the stock in the chamber g is further determined bythe adjustment of the disk L, arranged at the discharge opening of the chamber y by means of the hand wheels P-P and the associated parts. The discharge of the material is facilitated and packing of the stock eliminated by the bevelled inner face lc of the wall 1i' adjacent the feed opening K and the rounded cooperating face of the freely rotating disk L.

What I claim as new and desire to secure by Letters Patent is:

1. In an attrition mill, a cylindrical feed chamber formed with an inlet and having an open discharge end, rotary feed means for moving material from the inlet toward the open discharge end to form an attrition chamber, said feed means being adjustably positioned in said feed chamber andterminating at a point spaced from the open discharge end, a second chamber attached to said feed chamber formed with a feed opening restricting the discharge end of said feed chamber, the outer face of the wall of said second chamber defining the feed opening forming the outer wall of an attrition chamber defined at its opposite end by Said feed means, said outer face portion being bevelled toward the discharge opening, a shaft supported .in a bearing in a Wall of the second chamber, said shaft being in axial alignment with the feed opening and being longitudinally adjustable to position one end adjacent the feed opening, a rotatable disk on said shaft end adjacent the feed opening, said disk having a slightly curved Working face, a thrust bearing at the opposite end of said shaft, a thrust bar opposed to said bearing, guide pins fixed to said second casing and extending through said thrust bar at each side of said thrust bearing, the outer ends of said pins being threaded to engage threaded openings formed in hand Wheels, and spring means interposed' between the hand wheels and thrust bar for resisting the thrust transmitted from the feed means.

2. In a grinding mill assembly, a support, a cylindrical feed chamber mounted on said support and having an inlet and an open discharge end, an auger of less length than the feed chamber positioned therein, a drive shaft for said auger, means for adjusting said auger in said feed chamber to provide a chamber at theV discharge end of said feed chamber of a predetermined size, a disintegrator casing positioned Yadjacent the discharge end of the feed chamber, -said disintegrator casing having one of its Walls formed with a discharge opening centrally positioned with respect to the discharge end of the feed chamber and restricting the size of said discharge, a freely rotatable disk positioned in the disintegrator casing at the discharge opening and in axial alignment with said auger to normally oppose the passage of material through said opening in opposition to its movement under action of said auger, the marginal face of said disk being bevelled at an acute angle With respect to the plane of the adjacent Wall face, a support for said disk, resilient means urging said disk towards the restricted opening, and means for adjusting said resilient means.

3. In a grinding mill assembly, a support, a cylindrical feed chamber mounted on said support and having an inlet and an open discharge end, an auger of less length than the feed chamber positioned therein, a drive shaft for said auger, means for adjusting said auger in said feed chamber to provide avvariable chamber at the discharge end of said feed chamber, a disintegrator casing positioned adjacentthe discharge end of the feed chamber, said disintegrator casing having one of its walls formed with a discharge opening centrally positioned with respect to the discharge end of the feed chamber and restricting the size of the discharge opening, the face of said Wall within said feed chamber and defining the discharge opening being bevelled towards said opening at an acute angle, a freely rotatable disk positioned in the disintegrator casing at said discharge opening, said disk face being curved away from said discharge opening, whereby there is provided a restricted outlet to and from which the movement of the material is facilitated, and means for adjustably and resiliently urging said disk towards said restricted opening.

4. In a grinding rnill assembly including a cylindrical feed chamber having an intake and an open discharge end, a separable disintegrator chamber, one wall of said disintegrator chamber forming the closure for the discharge end of said feed chamber, said closure end wall being formed with a discharge opening of a diameter materially less than the diameter of said feed chamber, a feed screw having one end arranged under said intake and its opposite end terminating in spaced relation to said discharge opening to form a material accumulating chamber, the inner face of the Wall of said disintegrator chamber adjacent said discharge opening being bevelled at an acute angle with respect to the plane of the adjacent wall face, a freely revoluble disk arranged adjacent said discharge opening in said separable disintegrator chamber, said disk having slightly curved edges adjacent the Wall defining said opening which curved edges overlap the Wall dening the discharge opening, and said disk, discharge opening and auger each being arranged with a common axis.

TIMOTHY D. SHANKEL.

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