claim: 1. An extrusion mill cor@iprising a housing havipg front and Tear walls, a hollow shaft rotatably supported by said walls and extending beyond said front wall, a ring die @rarried on an end of said hollow shaft beyond and adjacent said front wall, a door hinged to said housing and adapted to enclose said die and engage the edge thereof to complete a die charnber, extrusion means within said die chamber carried by said door and adapted for with10 drawal with opening of said d-oor, and means for feeding extrudable material through said hollow sha@ft into said die chamber for extrusion through said die. 2. An extrusion mill coniprisin.- a housi@-ig havin.- front aiid rear walls, -a hollow shaft rotatably supported by 15 gaid walls and having a flange at one end beyond and adjacent said front wall, a ring die carried by said flarge, a door hin.-ed to said housing and adapted to enclose said die and engage the ed,-e thereof to coniplete a die chpmber, ex-trusion means within said die chamber carried 20 by said door and adapted for Nvithdrawal Nvith opening of said door, and means for feeding extrudable material through said hollow shaft into said die chamber for extrusion through said die, said feed means inelliding a feed screw lying within said hollow shaft and extending beyond 25 ihe other end thereof, and a feed screw housin.- for the extended por-tion of said feed screw, said screw hoiisin.including a feed hopper, and means for rotating said holiow shaft and said feed sr-rew. 3. An extrusionmill comprising a housing having froiit 30 and -rear walls, a hollow shaft ratatably supported by said walls and having a flange at one end beyond and adjacent said front wall, a rin.- die carried by s-,tid flan---e, a chatnber type door hinged to said housing atid adapted to enclose said die to form an extruded product cham35 ber thereabout and to engage the edge of said die to complete a die chamber, extrusion means within said die chimber, means for feedingextrudable material tliroiigh said hollow shaft into said die chamber for extrusior, through said die, and means for protecting the rotatable 40 shaft supportin-, means of said front wall from material in said extruded product cliamber, said protecting means including a block,:ng wall affixed to said flange and extending substantially to the inner peripheral wall surface of said extrusion chamber, a Tib along sa@d inner 45 peripheral wall surface adjacent said bloeling wall, and a shropd on said blocking wall overhan@ging said rib. 4. An extrusion mill comprising a housing having front and Tear walls, a hollgw shaft rotatably supported by said walls and extending beyond said front wall, a ring 50 die carried on an end of said shaft beyond and adjacent said front wall, a door hinged to said housing and adapted to enclose said die and engage the edge thereof to com@plete a die chamber, extrusion means within said die chamber, said extrusion means includin.- a roll fixli5 edly secured to a shaft extending through said door, bearing means carried by said door externally of said die chamber for rotatably supporting said roll shaft, and means fo@r feeding extrudable niaterial throu,-h said hollow shaft into said die chamber for eytrusion through 60 said die. 5. An extrusion mill con-iprisin-.- a housing havin.a front and rear walls; a bearing assembly in said front wall; a bearing assembly in said rear wall in ali.- nment with said -first bearing assembly; a hollow shaft passing through and 65 supported by said bearing assemblies; said hollow shaft having a flan,@e at one end beyond and adjacent said fi-ont wall; a ring die carried by said flange; a chamber type door hinged to said housing and adapted to enclose said ring die and engage the ed,@e of said die to complete a 70 die chamber and at the same time form an extruded product chamber about said die, said door havin- an external cylindrical flange on the front wall thereo and an insert in the front wall havin.- an opening concentric witli sa;d cylindrical Range and a discharge opening at the 7r, lower@end of said door; extrusioi means supported with-

in said cylindrical flaige and extending tlirough said door ope-iiing into said die chamber, said extrusion means includin.- a sle.-ve fittin.- into said cylindrical flan,-e and removably secured therein, spaced bearings within said sle-@ve, a shaft jolrnalled in said bearings and extendin.into said dia chamber, and an extrusion roll affixed to said shaft within said die chamber, said shaft having a flange adjacent said door; leak seal means between the ed-e of said shaft flange and said sleeve and between said shaft flan.-e and said door insert; said door, at the lowermost point of the junction of said cylindrical flange and door insert, having a passage for discharge of material escapin.- past said seals; and means for feeding ext-rudable material into said die chamber, said means including a feed screw lying within said hollow shaft and protruding beyond the back wall supported end of said hollow shaft, and a screw housin.- for the extended portion of said feed screw. 6. A pellet mill comprising a cylindrical die, means rc-tatably supporting said die at one end thereof, a closure for the opposite end of said die, an extrusion roll 3,010,150 6 supportir@g shaft journalled in said closure with the roll supporting end of shaft terminating within said die and the opposite end terminating in said closure, an extrusion roll fixedly mounted on said shaft within said die and i-,i extrusion engagement therewith, means for driving said die, and means for adjusting said extrusion roll with respect to the proximate surface of said die, said adjusting means compris;n,- a bearing housing on said -,Iosure, a bearing assembly in said bearin.- housi-@ig and including an 10 angularly adjustable eccentric bu@-,hing and spaced roller bearings surrounding the associated roll supporting shaft within said eccentric bushing, whereby angular rotation of said eccentric bushing will shift slightly the included roll supporting shaft. 15 References Cited in the file of this patent UNITED STATES PATENTS 2,06 3,404 Sel man ------ ---------- Dec . 8, 1936 20 2,33 6,114 Me akin ------ ---------- Dec . 7, 1943 2,79 8,444 Me akin ------ --------- July 9, 1957

Un'lted States Patent Office 31010@150 3,010,150 CONTAtMINA@rION FREE EXTRUSION MILL Edgar N. Meakiu, 372 Roblpx Ave., Hillsborough, Calif. Ffled July 14, 1959, Ser. No. 827,059 6 Claims. (Cf. 18-12) My invention relates to extrusion apparatus and more particularly to a mill for the pelleting of extrudable material. In the pelleting of material, where such material is of a fi-,icly divided nature, lubrication problems often arise, due t(y the fact that lubrication seals are not wholly immune to penetration by such finely divided material, and ultimately, servicin.- of the macbine becomes necessary. Further, cer+ain materials, as a pelleted product, must retain their initial purity, and contamination by oil from b.-arin.-s in the rnachine cannot be tolerated. Conventional pellet mill design offers no solution to these problems, Arno@ig the (Ybjects of my invention are: (1) To provide a novel and improved extrusion.mill adapted for use in pelleting of finely divided extrudable material; (2) To provide a novel and improved extrusion mill wbich will minimize the probability of interference with lubrication througli leakage of the extrudable material past the lubrication seals; (3) To provide a novel and improved extrusion mill which will minimize contaminaiion of the extrudable material through leakage of lubricating oil from the bearings of such machine. Addit,'onal objects of my invention will be brought out in the @ollowing description of a preferred embodiment of the same, taken in conjunction with the accompanying drawin-s, wherein; FIG. i is a vertical view in section through a machine embodyi-@i- the present invention; FIG. 2 is a front elevational view of the same, partly broken away to expose a detail therefor. Refe.-ring to the drawin,@s for details of my invention in its preferred form, the extrusion mill depicted therein coir@prises a housing I having a front wall 3 and a rear wall 5, each of which walls has a shaft opening therethrou.-h, with the openin,@ in the front wall of substantially greater diameter than that of the rear wall. Mounted within the shaft opening ol@ the rear wall is a bearinasse-mbly 11 to support the tail end of a drive shaft 13 while to the front wall, is afrixed a face plate 15 having a forwardly directed peripheral rim 17 and a rearwardly directed flange 19 extending into the shaft opening of the front wall, in which to mount a front bearin- assembly 21 to support the front end of such drive shaft, such beari@i.- asseinbly includin@@ a seal 23. ,issemblies il and 21 and interriiediate the bearing , mounted on the drive shaft -@13 is a drive gear 25 in on,@agement with a drive pinion 27 carried by a shaft 29 supported in beari-,ig assemblies 31, 33 carried by the front and reat walis respectively. The drive shaft 13 is of hollow, construction providinan axial pass,,ige 37 therethrou,-hl the shaft itself b.-in.of an inereasin@ outside diameter toward its -front end, where it terminates in an outside flange 39 and the passage ends in a conical discharge outlet 41. Removably affixed to the front end of the drive shaft -43 by a suitable conventional clamping ring 45, is a ring d;e 46 which will rotate with the drive shaft. This rin.die @s preferably formed at its free end in a frontal rib 47 having a @roove 49 alongthe base of such rib. A chamber iype do-or 51 mounted on hinges 53 along a front verlical ed,-e of the machine housing, is adapted Patented Nov. 28, 1961 2 in its closed position, to enclose the ring die 46 and engaae the free edge of said die to complete a die chamber 5 . 5, and at the same time mesh with the flanged face plate to provide for an extruded product chamber 57 about the die. The door is basically cylindrical in shape and includes a front circular wall 59 having an insert 61 eccentrically located therein and bounded by' a cylindrical flange 63, said insert having a shaft opening 65 concentric with 10 the cylindrical fla-rige 63 but eccentric to the axis of the die chamber. At its lower end, the door has a discharge opening 67 -through which is discharged the extruded product of the machine. Along the circle of contact with the free edge of the 1,5 die, the door insert carries a spring pressured ring seal 71 in a groove pro-vided for such seal. The cylindrical flanae on the front wall of the door constitutes means for supporting a bearin-. assembly 77 externally of the machine, in which to rotatably mount 20 a shaft 79 which extends through the opening 65 in the do-or and into the die chamber, where -@'t mounts an extrusion element 81 in the form of a roll. The roll shaft bearing assembly 77 includes an outer 25 bearing shell 83 adapted to sinoothly fit witliin the cylindrical flange 63, said outer shell being provided with an intermediate outside flange 85 adapted to engage the exposed end of the cylindrical flange where, by means of a clamping ring 87, the bearing assembly may be 3( securely retained in position; Longitudinally spaced beariii,s 91, 93 within the auter shell 83 support the roll shaft in proper aligned position. Adjacent the surface of the door, the roll shaft is formed with a laterally extendingflange 97. Between the 35 p,-ripheral edge of this flange and the outer shell 83 of the bearing assembfy, is a leak seal 99 while mountcd in a groove in the face of the flange, is a spring pressured ring seal 101 maintained in frictional contact with the door insert. 40 An end cap 105 bolted to the outer shell, perniits, in conjunction with the leak seal 99, of the retention of lubricant in the bearing assembly 77. The roll is preferably keyed or otherwise, affixed against rotation on the shaft, and is adjustable irto and out of 4.5 extrusion contact with the die, by making the outer shell 83 of the bearing assembly, of gradually varying thickness, whereby the roll shaft will be eccentrically disposed with respect to the outside diameter of th,- outer shell. Upon loosening the clarnping ring 87, the entire bearing 50 assembly 77 can then be angularly rotated sufficiently to gdjtist the roll with respect to the die, and when properly adjusted, its position may be fixed by again tightening the clamping ring. To relieve the strain placed on the door hinges by 55 reason of the co-mbined weight of the door and mounted bearing assembly arid roll shaft, a peripheral flange 109 o--Q the door adipted to abut the rirn 17 of the face plate, permits of the door, in its closed position, to be bolted 60 to the front wall of the machine housing. Material to be extruded, is fed into the die chamber through the hollow drive shaft 13 by means of a fced screw III lying within the hollow shaft and protruding beyond the tail end thereof where it terminates in a stub shaft 113 for couplin.- the screw to a source of drive power. A screw housing 115 for the exposed end of the feed screw, includes a feed hopper 117, and enter's at one end, the drive shaft passage to guaxd against loss of material being fed from the screw housing. A bearing as70 sembly 119 for the drive end of the screw is affixed to a wall of the screw housing. Material fed.iito the die,chamber, will accordingly be

3 exti-uded throligh the ring die and emerge therefrom as strings of extruded material which may be severed into pellets by a knife assembly 113 odjustably mounted in the cylindrical wall of the door, with the knife cornponent 125 held in substantial contact with the discharge side of the die. T'he mat@erial to be extruded is loaded into the hopper 117 of the screw housing and fed by the rotating screw III throi-,gh the hollow drive shaft 13 from which it is discharged into the die chamber 55 and then extruded ihrou@ the die from which the extruded material is ,h severed into pellets and dischar.-ed through the lower opening 67 in the door. Movement of the extrudable material into the die chamber will cause some of the material to pile, up against the door and more specifically the insert 61 in thefront wall of the door and around the exposed end of the Toll shaft 79, but escape of such material from the die chamber at this point is discouraged by the iing seal 101 in the flange of the roll shaft. In like manner, pellet dust or other fines created in the extrusion chamber 57 are blocked from filtering back into the die chamber 55 by the similar ring seal 71 in the engaging side of the front door insert. Access of such dust or fines from the extrusion chamber to the region of front supporting bearin.- assembly 21 for the drive shaft, is avoided by the provision of a blocking wall assembly 131 including a blocking wall 133 affixed to the flange 39 at the front end of the drive sbaft 13 and extending substantially to the inner peripheral wall surface of the extrusion chamber 57. Adjacent the front surface of this blocking wall and affixed to the iniier peripheral surface of the extrusion chamber, is a ringor rib 137 which will block movement of dust or fines by the free edge of th@e blocking wall along the inner surface of .the ext-rusion chamber. To discourage escape of dust or small particles by way of the extremely narrow space between the blockiiig wall 133 and the rib 137, a shroud 139 of ring shape is affixed to the blocking wall and in overhanging relitionship to the rib. The.aforementioned seal means 101, 71. and 13@l sei-ve to preclu@e contamination of the lubricating oil in the @.earin.-s of the machine by the material under extrusion. Contamination of the rnaterial itself by oil employed . in lubricating the bearings of the machine, is precluded primarily by the design of the machine which enables the bearing assemblies to be located outside of the die chamber ard extrusion chamber, whereby, even should one of the lubrication @e-als 2A or 99 go bad, leakage of oil from the associated bearing assen-lblies is not likely to result in such oil iinding its way into the die chamber or into the extrusion chamber to contaminate the material. To further minimize probable contami.nation of the material by such lubricating oil in the event of a leaky seal, escape openings are provided t<) permit sl,.ch oil to discharge from the machine and not accumulate therein. One or more such escape openings 143 are located in the door at the junction o@f the cylindrical. flan.-e 63 with the front wall thereof, while a sirailar discharge opening or openings 145 are provided through the cooperating rim portions of the face plate 15 and the door at the lowerMost point tllereof. While only one extrusion roll is provided for in the above embodiment of the invention, as many may be incorporated as the door can accomraodat-,@ From the foregoin,-, it will be a,)par6nt that the extrusion mill of the present invention viill fulfill all the objects attributable thereto and while I have diselose-d my invention in its preferred foi-m, it will 'ce apparent that the same is subject to change and modification without departin from the underlying pritciples involved. I accordingly do not desire to be limited in my protection to the specific details illustrated and desciibed except as may be nepessitated by the appelided clair-qs, 3,010,150 .4