US2565830A - Pelleting machine - Google Patents

Description

Aug. 28, 1951 WESTON 2,565,830

PELLETING MACHINE Filed July 15. 1949 3 Sheets-Sheet 1 Fig.1. Fig-.2.

INVENTOR A 0 #155 row ATTOR Y Aug. 28, 1951 R. WESTON PELLETING MACHINE Filed July 15. 1949 Fig.4.

Au 28, 1951 R. WESTON, 2,565,830

PELLETING MACHINE Filed July 15. 1349 5 Sheets-Sheet 5 Fig.7.

INVENTOR fior il-sro/v ATTORNEY Patented Aug. 28, 1951 PELLETING MACHINE.

Roy Weston, Toppenish, Wash., assignor of sixtyseven per cent to Harcourt M. Taylor and eight per cent to Herbert S. ,Buckman, both of Yakima, Wash.

Application July 15, 1949, Serial No. 105,038

11 Claims. (Grim-14) The invention hereinafter disclosed and claimed is of an improved pelleting machine for making pellets of suitable mixes of ground grains and the like through dies, by extrusion under sufficient pressure to cause the materials to come out in round wire-like continuous form, which is usually cut into short pieces or pellets as it leaves the die.

All of this matter so far recited is in daily use in a great number of feed mills, with a great variety of more or less satisfactory machines, all of which, it is believed, fall considerably short of what their users would like to have.

It is the object of the present invention to meet the following conditions, which have heretofore resulted in less than satisfactory machines because the conditions have not all been recognized or met.

First, the material is inherently springy and tends to rebound to an appreciable extent when a line-contact forcing member passes over a hole in a die that contains material under high pressure. This condition is met by a long tapered wedge that gradually raises pressure of the material in the holes of the die to maximum, followed without intermission or space by a polished final compressing member that maintains maximum pressure for an appreciable length of time by sliding over the holes while keeping a considerable number of them concurrently covered so that the inherent springiness finds relief in the direction that the material is wanted to travel.

Annular dies are well known. Some have holes in general parallel to the axis of the die, with line contact rollers or line contact shoes as the compressin element. Annular dies with plural rows of holes, circumferentially disposed in radial relationship to the annulus of the die with both rollers and shoes have been proposed and made and used; all of which, so far as can be learned, have a line contact and must work in actual contact under pressure, with the die proper, in order to get production in good quantity and then, only if the moisture content of the mix is raised above that which will product non-crumbling pellets.

I meet these objections and accomplish the objects of the invention with a first stage compressing wedge that operates in correlation with an annular die formed with a large number of generally radial holes, that cooperates with a circumferentially lengthened slim tapered curved wedge that is made integral with a final compression unit that has an arcuate compressing surface that matches with the inner circumferential surface of the die, to maintain pressure against the contents of the holes for an appreciably lengthened time interval. The wedge. surface and the concentric surface are blended together without any abrupt line of joinder.

When the machine is accurately made, with the butt of the wedge and the final compressing portion .thereof clearing the ends of the die holes by only a few thousandths of an inch, a very much higher pressure becomes .at once available; and dry material, such as alfalfa meal dry enough to fill the air with dust if thrown up, can be readily compressed into glassy looking hard pellets, without moistening, and requiring no kiln drying afterwards. The same is true of other mixes, as commonly pelleted. The hard glassy looking pellets, made without steam-- ing or wetting the material, can be fed by throwing onto a damp soil surface and last several times as long as the conventional pellet, if not at once consumed by stock.

Drawings accompany and form a part of this disclosure, in which:

Fig. 1 is a front elevation, at reduced scale, of a suitable machine in which my new die and compressor can be incorporated;

Fig. 2 is a side elevation of Fig. 1 at the same scale as Fig. 1;

Fig. 3 is a sectional view taken on the plane 33 of Fig. 1;

Fig. 4 is a sectional View taken on the plane 4-4 of Fig. 3;

Fig. 5 is a section taken on the plane 5-4), Fig. 3;

Fig. 6 is a section on the plane 6-45, Fig. 3;

and

Fig. 7 is a perspective view showing the front of the compressor formed with two curved surfaces, as will be hereinafter explained.

Describing the drawings in greater detail. Numeral i represents a main base, shown here to be of structural steel Welded, though this is schematic only. Vertically extending frame menu bers such as 2, are made rigid with the base I, and a cap member 3, forms a rigid mounting for the revoluble shaft 4, bearings for which are thestep bearing 5 and a bearing carried by the members 3, not shown. The members 3 also support the pedestals 6 and I, forming a heavy and rigid support for the pelleting die 8. A receiving pan 9 under the die 8 receives the formed pellets and means for their disposition have not been detailed since they are no part of the invention claimed herein.

Since with this type of pelleting machine the pellets themselves are very much harder than when made with the conventional type of machine, due to the greater compressing pressure made available, it will usually be expedient to break them 01f from the outside of the die, through which they will be extruded; hence conventional means adjustable to either break or out, such as" the crescent shaped. members l, are adjustably carried by arms- IO having an integral hub mounted on shaft 4. The shaft 4 is driven by the bevel gear ll meshed with the pinion I2, mounted on the shaft [3, upon which is mounted the driven sprocket I4, driven by the chain l5, from a conventional sprocket, 16 op erated by the gear motor ll, which also operatesthe lift conveyor [8, that returns smaller'broken parts of pellets and unpelleted material that escapes the compressor, to be described. Since the screen, the elevator and the main hopper l9 are conventional and not a part of the claimedinvention, they are not further described.

The pelleting die 8, as shown where broken away in Fig. 3 at the right, is madeof suitable material and provided with'smooth drilled pelleting holes 8, the drawings showing four rows in the vertical aspect. Owing to the mode of operation of the compressor, it is nearly essential that these holes shall be staggered as indicated in Fig. 6. planation of the mode of operation, wherein it is not well to have continuous lands in the horizontal'plane of the inside surface of the annular die. There is no novel construction in the die per se. Such annular dies have been proposed with rollers revolving in contact with their inner annular surfaces, to compress material through radial holes and other devices have proposed a shoe set aslant; but in bothcases a final line contact has resulted, which has proven unsatisfactory. My remedy, though simple, is effective and will now be explained in connection with the drawings;

The shaft 4 has mounted thereon a spider 251, formed of steel, with a plurality of jaws 2| within which the shanks 22 of the compr'es'sors 23 are closely fitted. Eachshank will-beheldby a suit-- able bolt' 2'4 through a slightly enlarged hole 25 in the shank and more accurately placed as by shims 26-, so that the final compressing portion of the compressor 23 will clear the. actual inside surface of the die'B, by asmall clearance, usually not over five thousandths of an inch. Theactual compressing faceof the compressor 23, isthe most important thing about the whole pelleting machine and the exact point of novelty over the pelleting machines that have preceded it. I-ts' compressing face has two curved surfaces that blendtogether without a ridge or other indication of where one beg-ins and the other ends. There is a curved primary or precompres'sing surface-that isa relativelydorig' curved wedge such as' the c'urve described by the radius 27, whose length is from the center 28' tothe curve 29. The-balance of the compressing face is cireular andconcentric with'the inside of the annular'dieil'fand', asnoted, it wilrr'evol've in very close relationship thereto but preferably without actual contact. The concentric or final compressing surface of the compressor should be'of sufi'ifcient circumferential length so that it will completely cover atleast two of the verticalrows of holes on the inside surface of theannular die;

The point of in fromwhieh theconcentricarc poi ion of the compressor is struck, isat 3 Gilt Fig. 3 coincident with the cen- This will be understood from the ex- I i terline of the shaft 4 in that figure and the radius line is indicated by numeral 3!.

The feed for the compressor originates in the main hopper i9 and may be distributed from the pan. 32 through spouts such as 33 in Fig. 3; from whence it is moved around into position for com- '-pressing' by the blades 3 3,. operated by the star wheels 35- ccoper-ating with the stationary pins 38 on the stationary die 8. Two star wheels are indicated and two feeders operable thereby, and other satisfactory feeding means may be substi'tuted.

Two additional compressors with auxiliaries can-be'isupplied for'dcuble capacity, especially if the die 8 is made of larger internal diameter. The star wheels 35 are revoluble on axles H which in turn are made rigid with the lower flange 2c of the spider 20., The feed shown is schematic; like all of the other parts of the machine, as a whole, save for the compressor with its wedge type'initial compressor per-tion and the holding final compressor portion, operating ccoperativ eiy with adie with properly spaced die holes. The rest ofthe .pelleting machine is not claimed. 1

Having fully disclosed invention so the art may fully understand the scope of its use and he results to be expected, what I claim asne w and desire to secure by Letters Patent is;

1. A pellet die and compressor .for cooperative operation in a machine, comprising a die mellbcr formed with a uniform intake face through which a plurality of generally normal holes are harmed, a compressor mounted for repetitious traverse over said intake face to compressmaterial through the holes, said compressor characterized by a tapered wedge-like initial compressing portion spaced from the said intakeiac'e at aha-extreme; tapered to approach very closely to said intake face to end the initial compressing portion and being continued as a smooth final com-pressing portion of full width and ofsu eh circumferential length thatfmore than two rows of holes are covered at all times, to: uniformly ccver'such' substantial area of said intake face with its'holes without actual contact. v

2. In a pelleting machine, an annular pelletfarming die, aaplurality-of rows'of pelleting. holes in said die, curved compressing wedges revolubly mounted within sai-dzdie .tQEfOlBG materi'al through said holes, -saidwedges formed with aleading, curved, wedge like precompressing portionthat smoothly changes to afinalcompressin'g portion of substantial length, the surface of which is concentricwith the inside: surface of the die and mounted to run very close to the inner surface of said-die, without actual contact.

3'. A :pelle'ting' machine for forming pellets f!'*"' l'l-'f(3@d material; having in combination theretlran' annular pellet forming die, axiallystaggered rows-of pellet holes radially placed through said die, material compressing wedge means mounted for revolution within said die to-coznpress-material through said holes, said Wedge ofcircuinferential' length with respectto theinsideof the die and formed withathinlea'ding end that gradually thickens to wedgingly prccompress material against said. rows of holes and a ilnal compression portion that issmeothlywith the thick end of the wedge, said that compression .portion'formed with a surface con'ccntriawithand very close :to the insideof the die and having sufiicient concentric surface; to 1concurrently-cover a'plur-alityof' axial rows of 1510 .68;

4. In a pelleting machine of the character described, an annular die provided with radial pellet holes through the annulus, said die rigidly mounted within said machine and forming a part thereof and means for extruding material delivered to a point within said annular die, through said pellet holes to be removed as pellets as extruded, comprising an elongated curved wedge revolubly mounted within said annulus, with its small end spaced from the die and its large end very close thereto to gradually force material against and into said pellet holes, said large end being continued for a substantial distance as an arcuate final compressor, the arcuate surface of which is concentric with the inside surface of the die, closely positioned with respect to said die surface and of sufficient length to maintain final pressure against an area containing a plurality of filled pellet holes, continuously, as said extruding means revolves within said die.

5. In a pelleting machine of the character described, an annular pelleting die rigidly incorporated with said machine, said die provided with a plurality of staggered rows of radial die holes normal to the axis of the die, a drive shaft coaxially mounted within said die, a spider mounted on said shaft, a plurality of material compressing elongated curved wedges carried by said spider in cooperative relationship with the inner surface of the annular die, to wedge material into the said die holes, each wedge so formed that its thinner end is spaced from the inner face of the die, its thick end is very close to but not touching the die and the said thick end is made continuous with an arcuate final compressing heel portion of substantial length, concentric with the inner surface of the die.

6. A machine for pelleting food products useful in husbandry, having in combination therewith an annular pelleting die, a plurality of generally radial pellet holes through said die, means for forcing material through said holes preparatory to parting the extruded material into pellets, said forcing means comprising an elongated curved wedge member mounted for revolution within said annular die and formed with a relatively thin end forward in the direction of its travel to gradually increase pressure on material between said wedge and said die to force it through said pellet holes, characterized by the said wedge having an elongated unitary heel portion, the outer surface of which is an arc concentric with the inner face of the die and movable in close cooperation with said inner face, to hold attained pressure against the material in said holes while said heel portion passes thereover.

7. A pelleting machine die and force feeding means therefor, comprising an annular die rigidly mounted in horizontal position, radial pelleting holes in said die, a shaft axially revoluble within said die, a spider mounted to turn with said shaft, within the die, a plurality of curved wedges carried by said spider with the thin end of each wedge spaced from the die and the thick end very close to said die, a heel portion formed integrally with each wedge as a continuation of its thicker end, the surface of said heel concentric with the inside of the die and of sumcient breadth and length to maintain each hole in said die under compression for a part revolution of the spider after it is filled by said wedge portion.

8. The structure as claimed in claim 7 and including a material feeding means positioned to feed pelleting material into place to be forced into the die by the wedges.

9. In a pelleting machine, a pellet die provided with a plurality of substantially parallel pelleting holes therethrough, said die made rigid with said machine, means for forcing material through said pellet holes to emerge as extruded pellet material comprising a plurality of wedges movable over the surfaces of the said die containing said pelleting holes to Wedge material through the holes, the thin end of each wedge being spaced from the face of the die and the thicker end very close to the die, said thicker end being continued by a final compressing portion of said wedge, and said compressing portion circumferentially covering a plurality of rows of holes in said die at the same time, to hold attained pressure therein, after the tapered filling wedge portion has passed over the said holes.

10. A compressor wedge for forcing material through pelleting holes of the character described in an annular pelleting die, comprising a curved wedge member of substantial circumferential length adapted to be revolved within such a pelleting die, the wedging surface thereof being a compound curve spaced away from the inside of the die as to its leading end to form a curved wedge initial compressing portion followed without intermission or space by a polished final compressing portion that is curved concentrically to match the inner curved surface of a cooperative annular die.

11. A compressor of the wedge type adapted to force material through pelleting holes in an annular die from inside to outside, comprising a curved wedge-like rotor for traversing the inner die surface, said wedge formed with dual, compressing portions, one of which is a curved wedge surface having one terminus substantially spaced from a circumference of the same diameter as a die which it is adapted to serve and the other terminus smoothly merging with the remaining compressing portion, said remaining compressing portion concentric with the inner diameter of I the cooperating die.

ROY WESTON.

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

UNITED STATES PATENTS Number Name Date 1,848,332 Estes Mar. 8, 1932 2,239,220 Permentier Apr. 22, 1941

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