US1954086A - Pellet mill - Google Patents

Description

E. T. MEAKIN April 10, 1934.

PELLET MILL Filed Nov. 14, 1931 4 Shuts-Sheet l I VM\ 2% max R INVENTOR. EDGAR Z" Mam/1v A TTORNEYS.

E. "r. MEAKIN A ril 10, 1934;

PELLET MILL 4 Sheets-Sheet 3 Filed Nov. 14. 1931 INVENTOR.

EDGAR 7T MEAKIN ATTORNEYS.

Patented Apr. 10, 1934 UNITED STATES PATENT OFFICE PELLET MILL Edgar T. Mealrin, Berkeley, Calif.

Application November 14, 1931, Serial No. 574,944

18 Claims. (Cl. 107-8) My invention relates to a mill, and particularly to a type of mill constructed to compress moldable material, whereby the material may be readily formed into pellets.

An object of my invention is the provision of a compact and durable machine, having a large capacity, and which may be readily and eco-' nomically manufactured.

Another object of my invention is the provision of a device, of the character described, in which parts may be quickly removed and assembled for replacement or repair purposes, without causing undue tie-up of the machine.

Another object of the invention is the provision of a machine, employing a die plate through which material is forced to form the pellets, the die plate being so mounted that it can be readily reversed when worn on one side, so as to positionthe other side for use.

Another object of my invention is the provision of a device, of the character described, in which the use of a costly screw construction for forcing the material through a die is obviated.

An additional object of myinvention is the provision of an apparatus, particularly adapted for use in conjunction with the mill structure, for feeding'material to the mill.

A further object of my invention is the provision of a device, of the characterdescribed, in which the structure is of such character as to allow facile and rapid adjustment of parts when this is desired.

The invention possesses numerous additional objects and features of advantage, some of which with the foregoing, will be set forthin the following description of my invention.

Referring to the drawings:

Figure 1 is side elevation, partly in section, of the apparatus of my invention.

Figure 2 is vertical sectional view of the mill and drive mechanism therefor. Part of the structure is shown in elevation to disclose clearly the construction. 1 I

Figure 3 is a perspective view of one of the knives employed in connection with the mill die.

Figure 4 is a horizontal sectional view taken in a plane indicated byline 4-4 of Figure 2.

Figure 5 is a side elevation, partly insection, of'the structure illustrated by Figure 4, looking in the direction indicated by arrow 5 in Figure 4. I

Figure 6 is a. top plan view of one of the spreaders or plows used in conjunction with the mill rollers shown in Figures 2, 4 and 5.

Figure 7 is a vertical sectional view of the spreader, taken in a plane indicated by line 7-7 of Figure 6.

Figure 8 is a front elevational view of the spreader holder andguide.

Figure 9 is a vertical sectional view of the spreader holder, taken in aplane indicated by line 9-9 of Figure 8.

Figure 10 is a top planview of the mill drive mechanism, looking in the direction indicated by arrow 10 in Figure 2.

Figure 11 is an elevational view of the inner end of the heater forming part of the ap- 'paratus, looking in the direction of arrow 11 of Figure 1.

Figure 12 is an elevational view of the outer end of the feeder forming part of the apparatus, looking in the direction of arrow 12 of Figure 1.

Figure 13 is a sectional view of the mechanism for imparting intermittent motion to the feeder conveying screw, taken in a plane indicated by line 1313 of Figure 12. Part of the structure is shown in elevation and parts are omitted from the view to illustrate clearly the construction.

Figure 14 is a vertical sectional view of the cam used in connection with the structure illustrated by Figure 13.

It is desirable to form stock and poultry feed into suitable sized pellets because this offers a clean and economical method of utilizing the feed. The apparatus of my invention is particularly adapted for this purpose; and in broadly descriptive terms it comprisesa bowl or pan, the bottom of which is formed by a die. Rollers are mounted on the die to compress and force the material therethrough as it is fed into the bowl; and knives are mounted below the die to 'cut the strings of material which are forced therethrough into suitable sized pellets. The die is mounted, in such manner and is of such construction, so that it may be reversed in position if one side becomes worn by continual contact with the rollers; and the parts are arranged so that this operation may be readily and easily performed. Suitable plows are mounted in the path of movement of the rollers for the purpose of spreading the material uniformly over the die; and the rollers are mounted for bodily movement away from the die, if adjustment or replacement thereof become necessary. A central shaft passing through the die is provided for supporting the rollers and die; and means are also provided for causing relative rotation between the die and the die.

Suitable means are provided for feeding proper quantities of material to the bowl; and in the case it is necessary to apply heat to the material to enhance compression and molding thereof, a heater is employed for this purpose. In the formation of pellets of the character described, it is sometimes desirable to form them of more than one type of feed uniformly blended therethrough. For this purpose, the heater is preferably provided with means for thoroughly mixing the material.

Mill structure With reference to the preferred modification of the apparatus of my invention, which I have chosen for detailed description, the mill structure comprises a housing of cylindrical shape, formed by the lower section 2 and an upper section '3. Upper section 3 is provided, adjacent the upper end, with a horizontally positioned Y internal flanged support 4 having the centrally positioned hub 6 forming a bearing in which the vertical shaft '7 is journaled. A wear washer 8, upon which rests the large gear 9, is mounted on. the upper edge of hub 6 and is journaled about shaft 7. Gear 9 is splined to the shaft, and the upper edge of hub 11 of the gear is formed with a circular groove 12 in which a split ring 13, mounted in a circular groove around shaft '7, is adapted to flt. From the preceding, it is apparent that, unless otherwise supported, the split ring 13 and correlated structure will provide a support for shaft '7 when the lower surface of the split ring bears on the hub 11, for a purpose to be later described.

Upper thrust bearing The upper end of shaft '7 is of reduced diameter and is journaled in a thrust hearing. The thrust bearing comprises a threadedhub 14 centrally positioned on the cover 16, the cover being secured to the upper end of section 3 and forming a gear box 17 between it and flange 4. A thrust nut cap 18, in which the upper end of shaft '7 is journaled, is threaded in hub 14; and the lower edge of thrust nut 18, is formed with a flange 19 between which and the thrust washer 21, roller bearings 22 are mounted. After thrust nut 18 has been turned to the desired position, it is fixed by means of a suitable lock washer 23, adapted to be secured to the hub 14. It is to be observed that thrust washer 21 is journaled about the reduced portion of shaft '7, and is therefore adapted to abut against the shoulder formed by the reduced portion, when shaft 7 is properly positioned.

Lower thrust bearing amt die Interposed between the mill housing sections is a conically shaped ring 24, having the outwardly projecting flange 26 on the lower edge thereof and positioned interior of the lower mill housing section. A die clamp 2'1 is removably mounted on flange 26 and is provided with a shoulder 28 forming a support for the outer edge of a relatively thick but flat and centrally apertured die plate 29, the die being firmly held aga nst a shoulder formed in the lower inner edge of ring 24. Seated in the central aperture of the die is a die block31, having upper and lower surfaces flush with those of the die plate and being formed with a downwardly projecting hub 32. Shaft '7 is formed, at its lower end, with a port on of reduced diameter and this portion-is journaled for rotation in the die block, the inner edge of the block adjacent the shaft having a recess within which is a suitable gasket 33 flush with the upper surface of the block and die. A split ring 34 fitting about hub 32 of the die block is positioned to bear against both the under surface of die 29 and die block 31; and the ring 34 is fixed in position by means of a lock-nut cap 36 threaded onto hub 32. The cover of lock-nut cap 36 has a large central aperture through which shaft '7 projects, and the cap is of sufficient length to provide a housing for the lower thrust bearing.

This thrust bearing structure includes a. ring 37 having a conical undersurface and bearing against the under side of hub 32, a plate 38 in which the shaft is journaled and bearing against the conical surface of ring 3'7, roller bearings 39 adapted to roll against the under surface of plate 38, and a second plate 41 upon the upper surface of which the rollers also bear. A thrust nut 42, projecting through the central aperture in looknut cap 36, is threaded onto shaft '7 and bears against the under surface of plate 41 to hold the bearing structure. To lock the assembly, a lock washer cap 43, threaded onto shaft '7 and over thrust nut 42, and a lock nut 44 are provided.

From the preceding description, it is seen that the structure thus far described can be assembled quickly by placing the upper end of shaft '7 through bearing 6, slipping gear 9 thereover in proper position, and inserting split ring 13 in its groove on shaft '7, to hold the shaft from falling down. The upper thrust bearing is then assembled in approximately the correct position; and then the lower thrust bearing and die supporting structure may be put together. During the assembling of the latter structure, shaft '7 can move vertically to allow proper positioning of the parts; and after assembly of the lower thrust bearing and die, the upper thrust nut 18 may be turned to the proper position and locked.

In case it is desired to remove the die plate 29 for replacement, this can be quickly and easily done, by removing'the die clamp 27, which comprises two semi-circular sections held together by bolts or inother words is a split ring, unscrewing 120 the lock-nut cap 36 a few turns, and removing the split ring 34. The die plate, having a central aperture of greater diameter than the diameter of lock-nut cap 36, can thus be readily passed over the lock-nut cap. During such removal, the split 125 ring 13 and correlated structure will prevent the shaft '7 from falling. Knives (for a purpose to be later described) are removably mounted on shaft '7, below the lower bearing and die; and it is obvious that they must be removed first. Since the die-plate has the shape of a flat disk, if one surface thereof becomes worn by contact with rollers thereover, it may be reversed in position with great facility and used on the other side. In order to allow access to the parts of the lower thrust 135 bearing and die plate, lower section 2 of the mill housing is provided with open sides 46, preferably along the entire length of the section.

Rollers 140 The conically sloped sides of ring 24 and the die supported at the bottom thereof form a bowl, in which rollers 47 are caused to rotate in order to compress and force material, fed into the bowl, through the die apertures. Preferably four rollers, equispaced about shaft 7, are provided. The rollers are journaled on the spindles 48 forming radally projecting arms of a spider 49, which is splined for rotation with shaft .7. A flange 51 is formed integral with shaft 7 to provide a support 150 for the spider 49; and the flange is preferably positioned so that the rollers contact with the upper surface of the die plate. Preferably, the rollers are of any suitable ballbearing construction and are each composed of parts readily removable for replacement or repair purposes, as indicated by the section of one of the rollers shown in Figure 2.

A second spider 52 having radially projecting arms 53, positioned over spindles 48, rests on the spider 49 and is also splined for rotation with shaft 7. To the ends of arms 53 are secured the downly projecting arms 54, having apertures in which the ends of spindles 48 are mounted. It is seen.

that both of the spiders are joined together, by the described structure, and since they are both splined to shaft 7, they can be moved vertically as a unit, opposite the large side apertures 56 in the upper section-=8 of the mill housing, so that worn or broken-parts of the rollers may be quickly and readily removed for repair or replacement purposes. Means are provided for elevating the roller and spider structure, comprising-the nut 57, threaded onto shaft 7 and the split ring'58 secured to the nut and havingan inwardly projecting flange 59 seated in a circumferential groove adjacent the top of spider 52. When the nut 57 is turned downwardly, it will hold the rollers 47 in close contact with the die. Should it be desired to allow a slight space between the rollers and de, depending upon the character of materialto'be forced through the die, it is to be noted that the nut 57 and structure correlated for use,

therewith, offers a means for providing this adiustment.

Plows Means are provided for spreading the material fed into the bowl, uniformly in the path of movement of the rollers and to a uniform depth in front of the rollers, including a plow 61,for each roller. With reference to Figures 4 through 9, each of the plows is 'U shaped, and has an inwardly projecting flange 62 forming the 'upper surface, and an angled flange 63, at the bottom, provided with an inwardly projecting extension 64 disposed at an angle, so as to throw excess material away from the inner side of the roller. Each of the plows is mounted in a U-shaped guide frame 66 secured, over the-rollers, to the side of arm 53 of spider 5 2. The back of the guide frame is cut away leaving sides 67 of triangular shape to allow roller clearance. Pins 68 are mounted, adjacent the top and bottom of frame 66, in apertures 69 formed in the sides 67 of the frame; and the front of plow 61 is adapted to bear against the pins. Plow 61 is supported in the guide frame, by means of a bolt 71 threaded in flange 62 of the plow, and having a collar 72 adapted to bear against the underside of an apertured ear 73, formed on the upper edge of guide frame 66, through which ear the bolt 71 passes. The upper end of the bolt projects through a hub 74, resting on the ear 73, and to which the bolt is keyed; and a sprocket 76 is formed on hub 74'. A handle 77 is secured to the top of the bolt, to provide means for raising or lowering the lower edge of the plow above the die, and thus regulate the depth of material in assembly. By turning handle 77, the desired adjustment for all of the plows can thus be readily obtained.

tion with shaft 7, are provided for cutting the material forced through the die into pellets. The knives are preferably circular and have stems 8-2 on the underside thereof, the lower portion of each stem being of reduced diameter to provide a shoulder 83. A spring 84 surrounds the reduced portion of each stem; and the springs are resiliently pressed between the shoulders 83 and the bottom of housings 86, formed at the upper end of the upwardly projecting knife supporting arms 87, so as to resiliently press the knives against the undersurface of the die. Arms 87 are formed integral with a hub 88 keyed to the end of shaft 7, the hub being locked in position by a lock nut 89 threaded onto the shaft.

When the pellets are formed, they are collected by a hopper 91, positioned below the die, and may be gathered by any suitable means, such as an endless conveyor 92 (Figure l) passing through the apertures 46 in the mill housing.

Mill drive mechanism As seen from the preceding description, the rollers, spiders therefor and knives are mounted for rotation with shaft 7. This is accomplished by turning the gear 9, splined to shaft 7. With reference to Figures 2 and 10, the driving means includes a suitable prime mover 93 such as an electric motor, secured to the upper part of the mill housing, having the rotatable shaft 94, which carries the small sprocket 96. A sprocket chain 97 connects the large sprocket 98 with the sprocket 96, the large sprocket being secured to the vertical shaft 99 journaled on the gear housing 17. Shaft 99 also carries a small pinion 101, which meshes with gear 9, to effect rotation thereof, upon starting of the prime mover.

To the hub of gear 9 is secured a bevel gear 102, meshing with the bevel gear 103 mounted on the horizontal shaft 104, projecting throughv the wall of the mill housing, and journaled therein and in the bearing 106 secured to the inner wall of the housing. The outer end of shaft 104 carries the sprocket 107, driving the sprocket chain 108, for a purpose to be later described.

Although, in the preferred construction of my device, the shaft 7 is rotated to effect revolving of the rollers and knives, which are secured for rotation therewith, it is apparent that shaft 7 may be stationary and the rollers and knives mounted for rotation therearound by any suitable drive mechanism, without departing from- The material, in the case where heat is necessary to enhance compression thereof, is fed from a heater 109, into the chute 110, which leads the material into the die bowl. The heater is provided with a double jacketed bottom to form a steam chamber 111 for effecting heating of the material. A longitudinally extending shaft 112, carrying the angularly disposed mixing and conveying paddles 113, is journaled in the end walls of the heater, and carries at its inner end the sprocket wheel 114, over which chain 108 travels, so as to effect rotation of the shaft 112.

An opening 116 is provided in the inner end wall of the heater, through which material flows into chute 110. To regulate the quantity of material which is forced through the opening 116,

' an adjustable gate 117 is slidably mounted, over said opening, in the guideways 118, as shown in Figure 11. A threaded spindle 119 is threaded to the gate 117, by any suitable means, and is journaled in the bearing 121 secured to the heater. By turning handle 122 at the outer end of spindle 119, the position of gate 117 may be readily adjusted.

Feeder posite end, which leads material into the heater from the feeder.

The conveyor screw is driven with a predetermined intermittent motion for the purposes previously set forth. Any suitable drive mechanism may be employed to perform this function. I prefer, however, to do this by means comprising the ratchet wheel 128 keyed for rotation to the end of the conveyor screw shaft 129, and which is adapted to be engaged by the spring pressed pawl 131. The pawl is mounted for slidable movement (Figure 13) in the guideway 132 on the inner side of the arm 133, journaled on the conveyor screw shaft 129. The free end of arm 133 is pivotedto the link 134, which in turn is pivoted to the arm 136, keyed for rotation with the heater shaft 112. Upon rotation of arm 136, it is apparent that an oscillatory motion will be transmitted to the arm 133, and that the ratchet wheel 128 will be turned intermittently when the pawl 131 engagesin the teeth thereof.

To control the degree of turning of the ratchet wheel 128 and consequently that of the screw conveyor 123, I preferably employ an adjustable cam structure, comprising the plate 137, having the flat semicircular projection 138 at one side and the flange 139 forming an arcuate cam on the opposite side. The plate 137 is journaled for movement about the conveyor screw shaft 129, and when held in the predetermined position desired, a pin 141, secured to the pawl 131, will ride over cam flange 139, to thus disengage the pawl and ratchet mechanism for the purpose described.

semicircular projection 138 on plate 137, is formed with a plurality of arcuately disposed apertures 142 at the bottom thereof; and the plate 137 is held in the selected position by means of a removable pin 143 passing through the selected aperture 142, and through an aperture in a retaining plate 144, secured below the cam structure, onto the upright 146 forming part of the support for heater 109.

I have described by apparatus wherein a heater and feeder are both employed, the heater being desirable in the case where heat is required to enhance compressing of the material. If the material requires no heat to perform the latter function, it is obvious that the heater may be omitted. However, if it is intended to make blended pellets consisting of two or more materials, it is preferred to employ the heater, without admitting steam thereto, for the purpose of effecting mixing of the material by means of the paddles 113 therein. r

Although I have described, for the purposes of ilustration, the device shown by the drawings, it is apparent that such'apparatus' may assume different forms within the scope of the following which I claim as my invention.

I claim:

' 1. In apparatus of the class described, a shaft, a die plate having an aperture through which the shaft passes, means for supporting the die plate, a plurality of rollers supported by said shaft and adjacent one face of the die for compressing and forcing material through apertures in said die, a knife for cutting the material into pellets as it is extruded from said die, and means for rotating the rollers and knife about the shaft 2. In apparatus of the class described, a shaft, a die plate having an aperture through which the shaft passes, means for supporting the die plate, a spider mounted for slidable movement along said shaft and having a plurality of arms projecting therefrom, rollers journaled onsaid arms for compressing and forcing material through apertures in said die, means for rotating the rollers about the shaft axis, and means for moving the spider relative to the die.

3. In apparatus of the class described, a shaft, a die plate having an aperture through which the shaft passes, a die block in said aperture and having a hub surrounding the shaft, means for supporting the die plate at the outer edge thereof, means including an element secured to said hub adapted to bear against the adjoining faces of the die block and the die plate, a plurality of rollers supported by said shaft for compressing and forcing material through apertures in the die plate, and means for rotating the rollers about the shaft axis.

4. In apparatus of the class described, a shaft, a die plate having, an aperture through which the shaft passes, said plate being capable of reverse positioning whereby either face thereof may be exposed for use, a die block in said aperture and having a hub surrounding the shaft, means for supporting the die plate for reverse positioning at the outer edge thereof, means including an element secured to said hub adapted to bear against the adjoining faces of the die block and the die plate,- a plurality of rollers supported by said shaft for compressing and forcing a material through apertures in the die plate, and means for rotating the rollers about the shaft axis.

ing, a ring supported by said housing, a shaft mounted in said housing, a die plate having an aperture through which the shaft passes, a die block in said aperture and having a hub surrounding the shaft, means for securing the die plate at the outer edge thereof to said ring whereby the ring and the die form a bowl, means for supporting the die block, a plurality of rollers supported by said shaft and in said bowl for compressing and forcing material through apertures in the die plate, and means for rotating the rollers about the shaft axis.

6. In apparatus of the class described, a housing, an upright shaft mounted in said housing, means for journaling the shaft for rotation, a horizontally positioned die plate having an aperture through which the shaft passes, means for 150 1 5. In apparatus of the class described, a houssupporting the die plate, a plurality of rollers mounted for movement with said shaft and adapted to compress and force material through apertures in the die, a knife mounted for movement with the shaft for cutting-the materialextruded from the die into pellets, and means for rotating the shaft.

'7. In apparatus of the class described, a housing, an upright shaft mounted in said housing, a thrust bearing adjacent the top of the housing and in which the upper end of the shaft is journaled, means for supporting the shaft in upright position, a horizontally positioned die having an aperture through which the shaft passes, means for supporting the die, a bearing adjacent the lower end of the shaft, removable means for.

forming a rigid assembly of the latter bearing and die, a plurality of rollers mounted for movement with said shaft and adapted to compress and force material through apertures in the die, and means for rotating the shaft.

8. In apparatus of the class described, a die, a roller mounted for movement over the face of said die for compressing and forcing material through apertures in said die, a plow, means for mounting said plow in the path of movement of said roller, and means whereby the distance between said die and plow may be adjusted.

9. In apparatus of the class described, an upright shaft, means for mounting said shaft, a horizontally positioned die plate having an aperture through which the shaft passes, means for supporting the die plate, a plurality of rollers, means for mounting said rollers for movement over the face of the die and about the shaft axis for compressing and forcing material through apertures in said, die, a plow for each roller, means for mounting each of said plows in the path of movement of its roller, and means for simultaneously adjusting the distance between said die and plows.

10. In apparatus of the class described, a die, a shaft positioned parallel to said die, a roller journaled on said shaft, means for moving the shaft and roller over the face of said die for compressing and forcing material through apertures in said die, a plow frame, means for mounting the plow frame in the path of movement of said roller, a plow in said frame, and means for mounting the plow for adjustment relative to the die.

11. In apparatus of the class described, a shaft, a die plate having an aperture through which the shaft passes, means for removably securing the.

die plate at the outer edge thereof, a die block in said aperture and having a hub surrounding the shaft, a split ring surrounding said hub and adapted to bear against the adjoining faces of the die block and the die plate, and a lock-nut threaded on said hub for holding the split ring, the diameter of the aperture being greater than that of the lock-nut.

12. In apparatus of theclass described, a shaft,

a die plate having an aperture through which the shaft passes, a die block in said aperture and adapted to close said aperture between said shaft and die plate, independent means for supporting the die block and the die plate, a roller supported I by said shaft for compressing and forcing material through apertures int said die plate, and

means for rotating said roller about the shaft axis. Y 13. In apparatus of the class described, a shaft, a die plate having an aperture through which the shaft passes, a die block in said aperture, means for supporting said die plate at the outer edge thereof, means surrounding said shaft and adapted to bear against the adjoining faces of the die block and the die plate, a roller supported by said shaft for compressing and forcing material through apertures in said die plate, and means for rotating the roller about the shaft axis.

14. In apparatus of the class described a shaft, a die plate having an aperture through which the shaft passes, a die block in said aperture and having upper and lower surfaces flush with those of said die plate, means for supporting said die plate at the outer edge thereof, means surrounding said shaft and adapted to bear against the adjoining faces of the die block and the die plate, a roller supported by said shaft for compressing and forcing material through apertures in said die plate, and means for rotating the roller about the shaft axis.

15. In apparatus of the class described a shaft, a die plate having an aperture through which the shaft passes, means for removably securing the die plate at the outer edge thereof, a die block in said aperture; a split ring surrounding said shaft and adapted to bear against the ad.- joining edges of the die block and the die plate, means for holding said split ring, said means being of less diameter than that of the central aperture of the die plate whereby upon the-removal of said split ring the die plate may be withdrawn thereover.

16. In apparatus of the class described a shaft, a die plate having an aperture through which the shaft passes, means for removably securing the die plate at the outer edge thereof, a die block in said aperture, a split ring surrounding said shaft and adapted to ,bear against the face of the die plate at the inner edge thereof, and means of less diameter, than that of the central aperture of said die plate for holding said split ring.

1'7. In apparatus of the class described a shaft, a die plate having an aperture through which the shaft passes, means for supporting the die plate, a roller mounted adjacent one face of the die plate for compressing and forcing material through apertures in said die plate, means for rotating the roller about the shaft axis, and means mounted on said shaft for vertically moving the roller relative to the die plate.

18. In apparatus of the class described a shaft,

a die plate having an aperture through which the shaft passes, means for supporting the die EDGAR T. MEAKIN.

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