US2538441A - Method and apparatus for filling containers - Google Patents

Description

Jan. 16, 1951 a c. F. CARTER 2,538,441

METHOD AND APPARATUS FOR FILLING CONTAINERS Filed Aug. 18, 1944 4 Sheets-Sheet l INVENTOR. CL AREA/CE E 64/2752 wmwyfsammd Arroelvs Y6 Jan. 16, 1951 c. F. CARTER 2,538,441

METHOD AND APPARATUS FOR FILLING CONTAINERS Filed Aug. 18, 1944 4 Sheets-Sheet 2 INVENTOR. CL mam/c5 f. 6427-59 QW A W Jan. 16, 1951 c. F. CARTER 2,533,441

METHOD AND APPARATUS FOR FILLING CONTAINERS Filed Aug. 18, 1944 4 Sheets-Sheet 15 FIG. 7

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IN V EN TOR. C1. 4e -c E C men-1e Jan. 16, 1951 c. F. CARTER 2,533,441

METHOD AND APPARATUS FOR FILLING CONTAINERS Filed Aug. 18, 1944 4 Sheets-Sheet 4 as 76 Fhu/vd H540 REL/5F fa Fay/vs H540 70 GMNTA JA'GMEA/TB D/A Men GM //9 INVENTOR. F/a. l5 CLARE/V05 E 614127252 ATTORNEYS Patented Jan. 16, 1951 METHOD AND APPARATUS FOR FILLING CONTAINERS Clarence F; Carter,Danville, Ill. Application August 18, 1944, Serial No. 550,001

Claims.

1 This invention relates to improvements in methods and apparatus for filling cans, cartons, jars and similar containers or receptacles with powdered or granulated materials, and particularly to a multiple-head automatic filling machine.

It is the purpose of this invention to provide a method and apparatus for automatically and rapidly filling and packing a container with a comminuted material of either fine or coarse density to a prescribed and constant volume, weight and density. This is accomplished through a stepwise procedure wherein a major portion of the filling is accomplished by means of a pressure differential between the container being filled and the bulk supply of powder, the preliminary filling step being accomplished by alternately reducing and increasing the atmospheric pressure within the container while agitating the powder being drawn into the container and thereafter exerting a positive compressing action upon the powder within the container in order to effect uniform packing. By this method, the apparent bulk density of the powder within the package may be adjusted to a substantially constant predetermined value.

My invention also concerns an improvement in machines for filling containers with powder which comprises means for accomplishing. the above described objectives and carryin out the above described method.

Whereas the conventional type of auger filler is slow and dusty in its operation, and whereas the vacuum type of filler will not successfully handle some of the granulated materials; this invention comprises improvements, thereover, embodying a means for packing powder uniformly in a container, together with certain more desirable principles of vacuum fillers. The resulting multiple automatic filler herein disclosed, operates rapidly in its continuous filling operations without dust. 7

The full nature of the invention will be. understood from the accompanying drawings and the following description and claims.

Figure l is a side elevation of the machine with parts broken away and shown in central vertical section. Figure 2 is a top plan view of the machine shown in Figure-l with the hood removed. Figure 3 is a sectional view taken on' the line 3-3 of Figure 1. Figure 4 is an elevation, with parts in section, of the adjustable filler control of which Figure 5 is a top view. Figure 6 is a sectional view of a filler head showing a modified form thereof and a modified form of associated vacuum control. Figure 7 is a developed view of the vacuum control valve sleeve. Figure 8 is a developed view of the parted vacuum head. Figure 9 is a plan view of the underside of the filler head shown in Figure 6. Figur 10 is a side elevation partly in section of an improved device for alternately reducing and increasing the pressurewithin and around the container being filled. In Figure 11, is a top view of Figure 10 taken through lines ll--|I. Figures 2, 13, and 14 illustrate a modified apparatus for agitating the powder in the filling throat and for In the drawings, there is illustrated a multiplehead filling machine having a base H] with supporting frame II in which there is provided .a

vertically extending hollow supporting shaft l2,

adapted to support at its upper end for rotation thereabout, a hopper supporting casting l3. For this purpose the shaft I2 has securedthereabout a fixed collar M to support the ball bearing race I 5 upon which the hopper casting I3 revolves. A tie rod I6 extends centrally'through the hollow shaft to secure over the top thereof a centering and closure washer l1.

Secured to suitable flanges about the casting l3, there are spaced sprocket wheels I8 and I9. Said sprocket wh'eels carry and are driven .by driving and conveyor chains as will be hereinafter described. At spaced intervals along said driving and conveyor chains, there are mounted thereon a series of brackets 20, each supporting a lifter plate 2| for receiving and positioning a container indicated at 22. Forthis purpose, a plunger 23 is slidably mounted in the inwardly turned upper and lower flanges of each bracket 20, carryingsaid plate at its upper end Each lifter plate 2| is provided with a finger 24' extending'upwardly therefrom for receiving, centering and maintaining the container 22 in aligned position thereon,v the stem of said finger being slidably guided'in the upper fiangeof the bracket 20. Adjacent each bracket 20 and depending downwardly from the lower chain and its sprocket wheel l9, there is a yoke25 having a lifter arm 26 fulcrumed thereto intermediate its ends. One end of the lifter arm'is .engageable .with a cam track 21. The otherend thereof is in roller contact with the lower end of the plunger "spring 29;

'moved from their respective lifter plates.

sprocket wheel l9.

wheel l8, as shown in Figures 1 and 3.

3 fiange of the bracket and its lower end seated upon a, collar fixed to the plunger. A lifting Spring 29 is connected to the pivoted arm 26 at one end and to the base of the yoke at its filler head under tension of the spring 29 until the armjfi rides onto the cam track 21, thereby permitting the plunger 23, lifter plate and container to be lowered by the spring 28.

The hopper casting l3 also supports hopperfid v which is provided with a central cone 3! extending upwardly therein. Extendin downwardly from spaced openings in the bottomof the'hopper, there is a series of filling heads 32, each being axially aligned with one of the lifter plates 2! and its plunger 23. Extending downwardly from the hopper through the throat of each of the heads 32, there-is provided ashaft 2M fitted with a chuck engaging with a member 33 having a powder compressing means at the lower end and whichmay alsobe equipped along its length with agitating means for agitating the powderin the filling head, throat and the entrance thereto from the hopper as'described" more fully hereinafter.

Inalignment with each of the throats and car- "ried in the upper part of the hopper 35,'are bearing's and liousing,*35. Shaft 34 extends upwardly therethrough and has secured at its-upper end adriving wheel or pulley 36, adapted to rotate one of the shafts when in alignment with one of the lifter plates '2! as hereafter'described. The

hopper 'is'provided with an upwardly-extending filler neck 31, centrally thereof, and within the annular series of pulleys 35 termined partial cycle of the hopper.

The lower end of the filler head is flared to rece ivethe mouthof the container .22 and center it with'respect' to the throat.

detail in Figures 6 and 9.

For controlling the amount of material fed into "the 'contain'ers according to prescribed volume,

weight and density, it is essential that the hopper be rotated at a predetermined speed, and that the containers 22 bev automatically fed to and re For this. purpose, there is provided a pair of dual 'driving and conveyor chains, one chain 38 ex-- tending about an idler sprocket 3'9, and the driven The other chain 49 passes about the idler sprockets 4i and the sprocket Said chains, in addition to driving the sprocket wheels l8, l9, serve to convey the containers to the filling heads.

The driving and conveyor chains' are' driven by a pair of sprocket wheels 42 mounted on a shaft 43 extending upwardly from a speed re- -duction transmission, as indicated at 44, the speed justment on a base 49 by a hand wheel 55. The base, and driving pulley may be any suitable variable-speed type and are for controlling the duration of the filling cycle of the containers.

The driving mechanism is supported upon an extended frame 5| in which the-shaft 43 of the driving sprockets and the spindle 52 of the idler The filler head is shown in greater sprockets 39, 4|, have their supporting bearings.

The pulleys 35 on the shafts act to rotate the powder compressing and agitating means attached thereto as hereafter described. They are driven by the motor 53, carried upon a supporting bracket 54 and adjustable relative thereto by a hand wheel 55. Said motor is adapted to drive a belt 56 as illustrated in Figures 1 and 2. The pulleys 36 are rotated only during a portion of the feeding operation, said belt 56 being'so arranged as to engage and drive said pulleys during a prede- Inasmuch as it is desirable to impart rotation to the shafts "for'only a predetermined time and throughout a portion of their travel, the relative position of their driving engagement by the belt 56 is controlled through'an adjustable filler control comprising idler pulleys 51, 58, which may be located inpairs at spaced points around the machine. Said idler pulleys, as shown in Figures 2, 4, and 5, are supported upon independent spaced vertical shafts 59 and 60, carried by an adjusting bracket 61 having a clamping :base 62. The'base' 6710f each pair of idlers' is clamped for adjustment about'the'frame H and so arranged that the belt 58 passes between the idlers, on the outer side of idler58-and on the inner side of. idler 51... Idler 51, therefore, acts tothrow' the belt'into frictional engagement with the driving pulleys 35 when they reach. a predetermined position and idler 58 directs the belt out of engagement therewith when the filling operation is completed.

By reason of thisadjustment, the members 53 are caused to agitate the material in the throat of the filling head and to'compress'the powder within the-container throughout a predetermined path of travel of the hopper during driving association of pulleys 35 with belt'55. The powder is drawn into the container by virtue. of thereducedpressure therein and. the member. 3 I compresses it, permitting additional-powder to be drawn in. Although the period of" engagement of belt. 56 .between pulleys '5lma i'nclude the entire timethe container is in thefilling position, it is'preferred-that-the shaft operate only a portion of this time. It is illustrated as engaging'at about 209 of the revolution ofthe'hopper, andremains engaged to a point between about 250"and1 275 where idler- '58 causes' it to'dis- "engage. The purpose of members' 33is not to feed the respective lifterplates 2 l'- of the conveyor chains 38'and'40. Said chains convey-each container on a lifter -plate zl' into alignment'witha fillinghead, at which position the driving belt 55 is out of driving engagement with the corresponding pulley "36,and the lifter-plate 2l-is in its lowermostposition through the action of the spring 28. The centainer having'been thus positioned by said-lifter plate-and centered thereon by the centering finger24, further travel thereof brings the lifting arm 26 to position for release from the cam track 21, whereupon-the lifting spring- 29- raises the lifter plate-with the 'mouth'of the container pressed and sealed under spring tension in filling position against the filler head 32. As the hopper casting continues to rotate, the pressure within the container is reduced, as for example, by a vacuum pump, and powder is forced into the container by the greater pressure on the powder in the hopper; the pulley 35 moves into driving engagement with the belt 56, according to the adjustment of the idler pulley 57, and is rotated. The number of revolutions is governed by the speed of the motor 53, and the duration of the'filling' operation is controlled by the rotation of the hopper casting governed by the speed controller 44. The amount of material introduced is governed by the volume of the container and the extent of packing or compression exerted on the powder after a substantial amount has been introduced, thereby permitting more to be drawn into the container. The amount of compression is governed by the fraction of the cycle pulley 36, is engaged with driving belt 55, and this, in turn, influences the amount of powder added since the reduced pressure automatically and instantly fills up the space provided when the powder compresses. Preferably, the belt 56 disengages just before the pressure is allowed to come to normal in order that dust may be withdrawn from the container and that a bridge may form over the mouth of the feeding head as hereinafter described, to prevent spillage. v

The cam is engaged to lift the arm. 26, permitting spring 28 to lower the lifter plate 2i. This frees the mouth of the container from the filler head, whereupon the container is carried therefrom by the link conveyor chains to a position for removal.

In order to accomplish the purpose of my invention, the pressure within the container is the pressure in the hopper is atmospheric, but in some cases, a higher or lower pressure can be maintained. I prefer to employ a sub-atmospheric pressure within the container and to return the pressure to atmospheric at the end of the cycle, this being the preferred pressure on the hopper.

The operation is accomplished by causing the powder to flow at a rapid rate into the container when the pressure is reduced therein. It should be understood that in carrying out my process, sufficie'nt pressure reduction is employed in the container so that the major portion of the filling is accomplished by virtue of this reduction in pressure and without a positive mechanical feeding action such as the conventional auger-type filling machine employs. The compressing member 33 has of itself no feeding action because flow of powder past it is too rapid. If anything, the member tends to impede the flow of powder except insofar as it exerts an agitating efiect.

With certain powders which do not flow readily the packing action since, as the level of powder.

rises to the top of the container, the powder tightly fills the space around and under the event, the function of the packer is not to feed or measure the powder introduced into the container, but to speed up the compressing of the powder, thus permitting additional powder to be drawn into the vessel because of the reduced pressure. I am able to approximately triple the rate of filling of containers over what can be done with a conventional auger-feed machine, and can increase the amount of powder introduced into a unit-size container by as much as about 7% over what can be introduced me like period of time by a conventional vacuum feed filler.

To apply the vacuum, a suitable vacuum pump is connected to a nipple Hi leading to theinterior of the hollow shaft I2 and vacuum head il in the hopper casting l3, as illustrated in Figure 6. The vacuum head is embraced by an apertured stationary ring 12 securely clamped to the upper end of the hollow shaft l2 by the washer I]. Said ring is viewed from the interior in developed form in Figure 8, being provided with a staggered series ofelongated apertures 13 and spaced intermediate downwardly-extending air ventsl4 registering with suitable ports 15 in the washer ll. Surrounding and conforming to said stationary ring there is a rotating ring l6, a development of which is shown in Figure '7. Said ring is provided with a double series of spaced apertures ll adapted to register periodically with the apertures l3 and air ports '55 in the stationary ring during their relative rotation. The rotating ring is locked to the rotating head 18 having apertured sockets 19.

Connected with each of the sockets 19, there is a flexible air hose, the upper of which is indicated as and the lower of which is indicated as 8|. Each pair of hose 80 and 8| is connected to opposite sides of the modified filler head I32, being in communication with the air ducts 82 and 83, respectively. Said air ducts lead to the semicircular screened openings 84 and 85, also designated as segments A and B, respectively. Surrounding said semi-circular screened openings, there is provided an annular gasket 86 against 'which'the upper edge of a large mouthed container engages.

In operation, as the hopper casting I3 is rotated,"the rotating ring 16 rotates relative to the stationary ring 12. This brings the aperture 11 of the rotating ring in periodic registry with the elongated apertures 13 and the ports 15 of ducts 14. Each pair of apertures TI is connected through the flexible hose with one of the filler heads 132 which comprise a modification of and is otherwise similar in its operation to the heads 32. The upper series of apertures 11 being connected with their respective hose 80, lead to the screened opening 84. The lower series of the apertures 11 communicate with their respective hose 81, leading to the screened opening 85.

With a partial vacuum being maintained in the vacuum head 1! air will be drawn from the container through first one and then the other of screened openings 84 and 85. This has the effect of evacuating the air in the container to permit introduction and some packing of the material therein and at the same time, remove and carry away'any dust developed in the filling of the con-a entrapped: air;from the :;hose B-I and there are no apertures in that portion thereof extending from the unloading stations of the hopper. Immediately uponthe filling operation commencing, the apertures I1 of the rotating ring will engageboth anupper. and loweraperture I3 in the stationary ring. This has, the effect of initially withdrawing air; from the container through both screened openings simultaneously for about 30 of the hopper'rotation.

Upon apertures I3, 1! initially passing out of registry, apertures I? of the rotating-ring register with air ports I5,.allowing the air hose to fill up with air at atmosphericpressure. Thereupon apertures 11 move outer-registry with, the ports I5, the lower-aperture 11 then registering with thelower aperture-I3. This. evacuatesthe air' trapped in the lower; hose'8l, and drawsair from the container upwardly through the screened opening 85 in'the; head while-at the same time, drawing. the trapped- .air from the hose 80 in the reverse direction through the, op-

posite-screened opening-84 to therebyunclog the latter. Continued rotationof the hopper moves the-lower apertures 11' out of. registry-with lower aperture: I3 and brings; it. into; registry with the next following air ventl4-,.ifilling .hose 8| with air at atmospheric pressure. ,Thereupon the-upper aperture 1! registers, with theupperaperture I3 to withdrawair from the' container upwardly through the screened opening 84 and-draw the downwardly through; the screen 85- to unclog it. This-{cycle of pulsations; first-drawing airw upwardly from the container through the screen;;on:one:side of the head; and drawingentrappedyai-ri from, the-hose .down; through: the: ODDOSitEYSCI'GBII'jtO"HI1C10git, isrepeated,?first onone side ofthe head-and-then thepther during; each :filling operation.

- By means-of the combined packinggmechanism and; intermittent pulsating vacuum control, ad-

where a dense packing is desired. Thisresults in a packaging-operation which is. accurate as? to quantity, weight and density, aswell as. being dustless.

As claimed herein, the driving belt and-wheels or pulleys for the packers and hopper may bein the form of link'belts or chains and sprocket wheels; or the belts may be of a character for driving flat-faced; pulleys orrsheaves. Also the comminuted; material may beof varying degrees vof-iinenessi. e.-,; either fine and powdery or coarse andgranulated. With theformer, it is moredesirable to utilize a greater vacuum, that is, a lower internal pressure, than is needed. for coarser'materials.

.Figure -10-is.:an improved device foreffecting the." alternate reduction and increase in pressure within the container and may. be used in place of the device above described. One of these may be used ior each fillinghead. althoughin some cases, one may be used for each pair of heads.

The-,deviceconsists of alower block- I'IIILand upper-block IOI, upon-whichhead, I02 isplaced. The upper block,xthe lower block and the head may beassembled by the conventional means such as stud bolts I03 to produce a tight seal.

Lower block I00, which may'comprise a single casting, contains a plurality of guides, through which pistons I-05',-I06, I01 and I08pass. The-guides I04; serve also as supports for springs I'Il9.-.which bear at one end uponthe base of block IOU-,and atthe other end upon a collar III] attached to the pistons. Also attached to this collar, is .a yoke: I I I having a journal therein for the bearing I I2 of wheel or, roller I I3. A threaded holeis drilled in. theupper end of the pistons and is designed toxreceive-valve stem I I4 which'is adjustable and-;-maybeheld inany desired position by locknut,- I I5. Intermediate in the valve stem lengthisa washer, III which may be attached to-or integralwiththe valve stem. The valve-stem passes through an elastic diaphragm, H9. A spool, IIB-rides upon. the diaphragm and supports the valve, I I6 which may be held in place by a means such as washen-IZI] and nut, I2I. The other valve assemblies are similar to the one described. 7

The valves illustrated. inFigure l0 have novel features which are particularly useful in connectionwith operationsassociated with dust or powder which may tend to accumulate on valve seats and heads preventing their proper functioning. The valve head comprises a; resilient disk-cf suitable material,- such as rubber orsyn- ,theticelastomers such asneoprene, chloroprene, etc. The disk has aV-Winged member extending oi-rcumferentially around it. This-may comprise a ridge or roll of rubber. The preferredmethod of forming the head --is by-molding it from the proper material, or the head may be made byincising; adisk circumferentially and then compressing 'theiportioninearest the center. Ahole is provided for'insertion, on the valvestem. Although any suitable means of attachment may be used, as illustrated-i-nFigure 10, the valve head .I I6 is placed on'the-valve-stem over spool IIB which is 101 smaller cross-section than the resilient head. :A washer I29 also of smaller-diametenthangthenhead, is placed over the head and drawn up tightly by means of nut I2 I. This compresses-the. mid-portion of, the rubber head and tends: to throw the winged member upward toward the valve seat, The travel of the valve stem is set so that the wings strikethe valve seat before. the valve is completely closed. The upward travel of' the valve causes the wings to spreadoutward in all directions across the face of the valve seat. imparting .a wiping efiect, thus forming a tight seal and at'the same time, cleaning the valve seat of, any powder or foreign matter. cling-ingthereto.

The upper block IEII is-designed torest upon a rubber'diaphragm' I19, and as previously mentioned, maybe fastened to the lower block by conventional means. The rubber diaphragm may serve-as a gasketbetween the upper block Iili and lower block I98. Between the head I82 and block IBI is a rubber-lining 53!] extending, except for openings as described, over the entire surface of head I62. If desired, it may be'cemented to head I02. As illustrated, it serves: as a gasket betweenblock IGI at. head I02. It is within the scope of the invention that only the portion of the head adjacent to. and comprising the valve seats be rubber lined.

Block IUI maycontain an aperture I29 which may be threaded to receivea nipple. This may be connected with a hood or shroud surrounding the container, these being used when the container is collapsible. to permit the pressure to be kept equalized inside andoutside the container. When a rigid container is used, the opening I29 may be plugged. Cylinder head I22 contains ports I22, I23, I24 and I25. ,These ports are equipped to be attached to suitable conduits. The valves, by virtue of their design and the material used, tend to wipe the face of the rubber lines I30, removing powder which may cling theretoand preventing faulty action due to plugging of the ports. r

The operation of the device shown in Figure is as follows and may be further clarified by reference to Figure which is a diagrammatic illustration of the process cycle. I The wheels II3 ride upon cams (not shown) which may be supported in a conventional man- 'ner and which are cut so as to produce cyclic operations such as are illustrated in Figure 15.

The 0 point in the Figure 15 is the point about 58 before the container first is engaged with the filling head. At this point, the relief valve I is open to the atmosphere. When hygroscopic powders are employed, the relief valve may be attached to an air dryer or air conditioner. The

ports I22 and I24 lead through ducts or conduits attached to the respective sides A and B of the filling head '(see Figure 9) and both valves H6 and I21 controlling ports I22 and I24 are open until the hopper has passed through about 58 of revolution. At this point therelief valve I25 is closed and the vacuum valve I 28 is opened, reducing the pressure within the container. Both sides of the filling head are open at this point. At about 86 of revolution, the vacuum valve I28 is closed'and the relief valve I25 is opened in order to allow the pressure to. return to atmospheric and to clear thescreens. 'Although the pulleys 36 may be engaged at this point, in the preferred operation, this is not yet done, "al-" though as stated before, this depends on t the character of the powder. At this point, the vessel has beenpartially filled with'powder by the vacuum actions I I Valves I25 -and-l2l are closed at 96 revolu tion, valve l I 6- remains open, vacuum valve I28 opens and remains open to'125 revolution, at which tinii it (310588,"171'16 relief valve I26 opens. This permits air to pass back through section A of the filling head screen and clear it of powder. At 133 revolution, valve I25 to the relief port, and valve I I6 to one filling-head port A closes and valve I 21 to segment B and I28 to the vacuum line opens and remains open to 163. The vacuum is then shut oil and the relief valve I26 opened to permit air to pa s back through the 1 screen on the side B of the filling head controlled by valve I2! and swept clean. At 171, the

vacuum valve I 28 and the valve I I6 to filling head A open and the relief valve I25 closes permitting a reduction of pressure in the container through the side of the filling head controlled by valve I It. At 201, the vacuum line valve I28 closes and the relief valve I26 opens to clear the screen on the A side of the filling head.

At about this point, the container has as much powder as can readily be introduced by vacuum means alone and according to my preferred operation, the packer begins operation by virtue of the engagement of the driving belt 56 with pulley 36. In those cases, where the packer is equipped with agitating member, it usually begins to function as a packer at about this point and the powder within the container. is compressed. The exact point will depend in part on the duration of the cycle. the degree of vacuum and the flowin characteristicsof the powder, The point'at which the packer is disengaged may vary, butin one preferred embodiment, this is done whilesthe container is evacuated in order that there be no dusting when the container is finally disengaged from the fillinghead. In any event, it is preferred not to operate the packer after the pressure in the container is restored to normal. In

" order to completely fill the container,vacuum and filling valve I I6.to the filling head is opened.-

Thepacker may continue to compress the powder within the container from approximately 209 to 277 of revolution during which time, additional powder is being supplied by virtue of the vacuum to fill the space made by compressing the powder already in the vessel. At 277, the packer has preferably stopped and the vacuum valve I28 closed; relief valve I26 is opened and so is valve heads, clearing them for the next cycle. The

period from 277 to the starting position is '00-- tainer. An additional function is to permit a slight bridge to form over the mouth of the.fil.l-'

ing head which is tapered for this purpose. .This

' prevents spillage of the powder between'the timethe filled container is removed and the next empty is put in place.

In large capacity machines with large filling heads, several taperedopenings may be provided in the 'head. Theta-per begins below the packer f. and becomes smaller toward the lower outlet of with comminuted material hasadvantages over those machines heretofore used for this purpose 1 in that it provides rapid filling and at the same time, more uniform' packing of the material] Combination ofivacuum and-auger filling havebeen used but these methods dependedv upon the auger to supply the filling. The vacuum was intended to eliminate dust due to air displacement in the container. The vacuum did not aid otherwise in the filling operation, indeed could not if the purpose of the auger for measuring powder were to be accomplished. As a consequence, the rate of filling is no greater than that of a regular auger filler, ince these machines use the auger to measure the amount of material introduced into the container. They depend upon the auger operating a certain fixed time to do the filling and hence must design the auger and limit the vacuum used so that the auger does all the filling work. If this were not so, there would be no control over the amount of material introduced insofar as the auger is concerned.

My device on the other hand, does not depend on an auger feed. It uses a vacuum feed for the actual introduction of the powder, but it sup.- plies a further feature in that the material already introduced canbe packed more compactly and uniformly. This permits the use of a smaller This permits a back blast of air to both In some cases, the operation of the packer may be stopped between about 250 and 275: largely to permit removal of dust from the con- 11- container for the same "W'eightbf material than an be used-with vacuiitn'flll-ing' alone,- and'at the same time,- increases the speed of fillingl en'or m'ous'lyl The apparatus is'u'sefiil forothei" purposes as well -as 'for filling containers, for'examp1e'm-sup plying'powdred resins, plastics, wood fiben clays' etc; to'm'old forms in connection with 'th" echniqiie of' molding from powders dvelop'ed -in the last fewyears. Une m'achine may supplyseveral molding machine's'and maybe synchronized with it.

I claim as my invention:

1. #An apparatus for filling containers with c omn inu'ted solids'which comprises a rotating hopper, aplurality'of filling heads depending thererrcin, zneans for al-igning anden'gag'ingcon ta'i'riers with-said 'filling heads, anner-alter: nately" reducing and increasing the pressure within'tl'ie containers *while in fillingrelationship witli" s'aid heads, "mechanic-a1 means i associated with each filln g neaq for compressing the powder' thu's' introduced, means tor reducing the pressure '"with'in trie' said container cbrilatd' wltnthe operation of -said compressingmeans and means for removing the'filled container;

2'. a nlling'rnachine for loading coin miiiuted solids" have a' container; said machine comprising ahopper'and"a fill'inglhead and having a condu it' containing a'throat communicating between said 'hdpp'er "and said filling" head, means for alternatly redncing' and increasingthe pressure within said container 'so as to draw 'comm'inuted solids "through said "throat from said "hopper; a" compressing and agitating "means" extending into said throat' and terminating adjacent the mouth thereon said throat being" tapefedat its =termi n'a'I*end,- the taper beginning "at a point-below thetermination or the agitating and compress ing means, said means for reducing the pressure"- in said container being synchronized withtheoperation of said' compressingmeans; and means for'removingthe =filled 'container;

apparatus for" filling containerswith conuninuted solids which-comprises "a hopper, a plurality of filling heads depending therefrom; in ns -for'aligning andrengaging containers with said filling heads, means foralternatelyream-- ing- :and increasing --the pressure within the con tainers while'in filliilglehtionship with-=said= heads; -mechanical means associated with each filling head for'compressingthe powder" thus in= troducexf saidimechanicalfmeans comprising a section of a screw, said- :means'for reducing 'the pressure'within said container synchronized with the operation of'said compressing'means, and means for removing'th'e" filled container.

4. 'An apparatus 'for filling containers with comminuted solids'which comprises a-hopper, a plurality of filling heads depending therefrom, meansforT'aligning and engaging containers with saidrfi'lling heads, meansfo'r alternately reducing and increasing thelpressure within the containers' 'while'in filling relationship with said head, mechanical means associated with each filling head for compressing the powder thus introducedysaid mechanical means comprising agitatingmeinbersand a packing member, said means for'reducing' the pressure within said container synchronized with 'the operation of said compressing 'means and means for removing the filled-container.

5 A method for filling containers with com- Ininuted"'s'olids' 'whi'chcomprises' reducing the pressure within a container whilein filling relations'hip with a filling head thereby filling said container substantially to capacity "With'loose powder but without substantial-positive mechanical feeding action,- then mechanically compressing-the "powder'thus drawninto said container while maintaining a reduced" pressure therein during the compressing 'Steptherebysupplying additionalpowd'er to the container,-stoppingthe mechanical compressing action and restoring the pressure within" the container" to atmospheric pressnre and "removing thefilledcontainer from engagement with the filling head.

CLARENCE-F. CARTER.

REFERENCES CITED Theioliowing references are "of record in the file ofthis patent? UNITED STATES MTENTS Number Name Date 346,265 Charlton et ale July 27; 1 886- 648 702 1900 1,'452;585- -1Q23 1,520,669 .1924 1-,-880';840 1932 13981585 1934 2;1'70;469= Carter I ugx 22,1939 2,443-,182'

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