US 2815621 A
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Description (OCR text may contain errors)
Dec. 10, 1957 c. F. CARTER 2,815,621
METHOD AND APPARATUS FOR FILLING OPEN MOUTH RECEPTACLES Filed April 28, 1955 VALVE flv START FIRSTCYCLE SEC'OIVDGVCLE HEAD VCUM- A HEAD RELIEF A HEAD RELIEF-B VALVE 640.950 III- VALVE @PEN INVENroR Clalelu'el! Cwrel ATTORNEYS United States Patent O METHOD AND APPARATUS FOR FILLING OPEN MOUTH RECEPTACLES Clarence Freemont Carter, Danville, Ill. Application April 28, 1955, Serial No. 504,488
9 Claims. (Cl. 53-22) This invention relates generally to a method and machine for lling open mouth receptacles with particulate material and more specifically to a method and an apparatus for use in the filling of open mouth receptacles which are provided with an impervious open top bag liner into which the particulate maten'al is dispensed.
The problems encountered in the filling of receptacles with finely divided powdered material have been recognized for some time. The primary problem in this field results from the characteristic of this type of material to accumulate air between the powder particles so as to make the material fluffy and of low density. Such entrained air is difiicult to remove so that the material will be compact and of high enough density in the shipping container such that the material will not settle to any substantial degree due to vibration encountered during shipping. On the other hand, the existence of such entrained air between the powder particles is an asset during filling in that it enables the material to flow freely, thereby simplifying the handling of the material in directing it into the receptacle to be filled.
The instant invention is directed to solving a particular problem encountered in filling lined receptacles with particulate material and in compacting the material dispensed into the receptacles. Such receptacles, as Ifor example cylindrical walled drurn containers, are provided with an impervious bag liner where the particulate material to be transported in the receptacle has a characteristie of absorbing moisture or Where it is contemplated that the receptacle may come in contact with water in shipment. In the absence of an impervious liner, the walls of the receptacle may permit moisture to reach the material within the receptacle.
Where open mouth receptacles, as described hereinabove, are to be filled, with an impervious bag liner inserted thereinto to receive the material, it has been found diflicult to properly position the liner within the receptacle so that a full quantity of material may be dispensed thereinto. Where the bag liner is simply positioned within a drum container with the liner mouth overlapping the upper end of the open mouth container, it has been found that air very often becomes trapped between the liner and the wall of the container so that a full measure of material cannot be dispensed into the liner. To overcome this diiiiculty and insure that the liner is in juxtaposition with the particular receptacle wall, the hereinafter described invention has been developed.
As a further problem solved by the instant invention, compacting or increasing of the material density is achieved so that the receptacle is rapidly filled with a full quantity of the powdered material. In comparison with prior known methods for compa-cting powdered materials, as by agitating the container being filled, the filling method of this invention is substantially faster in completing the filling of a particular size receptacle and also results in a more compact fill so that during shipment settling will not take place to any marked degree.
2,815,621 Patented Dec. 10, 1957 It is an object of this invention to provide a method for filling open mouth receptacles such as drum containers and bags with finely divided particulate material to produce a high degree of compacting of the material in a minimum filling time.
It is a further object of this invention to provide an improved method and apparatus for filling open mouth receptacles with particulate material, which apparatus is especially adapted for lling receptacles wherein an impervious bag liner is employed to line the inner wall of the receptacle.
It is also an important object of this invention to provide an apparatus for filling receptacles which have an impervious liner disposed therein wherein such apparatus includes a plurality of perforated conduit means positioned intermediate the liner and the inner wall of the receptacle to enable withdrawal of air from between the receptacle wall and the liner so that such liner will be juxtaposed with the interior wall of the receptacle as the material is dispensed thereinto.
Other and more specific objects, features and advantages of the invention will be apparent from the detailed description given below taken in connection with the accompanying drawing which forms a part of this application and illustrates by way of example a preferred arrangement of the apparatus for carrying out the invention. In the drawing:
Figure l is a cross-sectional view of a filling machine incorporating the features of and operable in accordance with the methods of the instant invention;
Figure 2 is a diagram representing the relationship of the valves on the apparatus of Figure 1 during the various stages of a filling operation.
Considering the structure of the invention as illustrated by Figure 1 on the drawing, the various valves incorporated into the filling apparatus are numbered consecutively 1 through 7. More specific details and description of these valves and their sequence of operation will be given in connection with the description of Figure 2 on the drawing and the overall operation of the filling machine. Reference will also be had to the valves individually in connection with the description of the overall apparatus.
The filling apparatus includes a lift plate 10 which is mounted on a lifting cylinder 11. Cylinder 11 may be associated with pneumatic or hydraulic lifting means (not shown) in a manner such as suggested in my prior Patents 2,360,198 and 2,613,864. Mounted above the lift plate 10 is a filling head 12. A container encircling shroud 13 is bolted to the head 12 by fasteners 14 and extends downwardly beneath the head to engage with the lift plate 10 upon the raising of such plate by means of lifting cylinder 11. A flexible seal element 15 is provided around the lower end of shroud 13 to engage with the lift plate 10 and form an air-tight seal therebetween. It will be recognized that upon the raising of plate 10 into engagement with the lower end of the shroud 13 there is formed a chamber for the container supported on plate 10 to be filled. This chamber is evacuated to assist in the filling operation as described in detail hereinafter.
A pair of ducts 16 and 17 communicate with the charnber within shroud 13 and are provided with valves 6 and 7 respectively. Valves 6 and 7, as well as the other valves illustrated on the drawing are of the diaphragm type wherein flow through the valve is controlled by the magnitude of the pressure applied to one side of a diaphragm. The application of pressure to such side of the diaphragm closes the valve and upon release of the pressure and/or upon the drawing of a vacuum on the side of the diaphragm, such diaphragm is moved away from the valve seat to open the valve, This type of valve has been found to be particularly well suited for use in controlling the sequence of operation of the container filling apparatus of this invention. In view of the fact that fthe `construction of this type .ofwalve is wellknown a detailed illustration and description ,thereof is notdeemed necessary.
The .duct 16, .the flow .through which is controlled by valve 6, is connected to a suitable source of vacuum or low pressure so that upon opening valve 6 the interior `of the shroud will be evacuated. Duct 17, controlled by valve ,7, communicates with the atmosphere exterior of the shroud so ythat upon opening of valve 7 the shroud interior will be placed in communication with atmospheric pressure.
`(.onsidefing .more `specically `the ydetails of kfilling head 12, such head is provided with a pair of separate compartments 20 and 21 which are formed by a partition 22 which extends radially outwardly` on opposite sides of 4a material feed inlet tube 23. Thus, the compartments ,21)4 and A2,1 are maintained separate from one another. A screen `24 is provided across the lower opening of compartaient 2.0.a11d a screen k25 is provided across the lower opening of compartment 21. A duct 430 `communicates with compartment 20 and is provided with va valve `4 interposed therein. Duct 30 is ,connected with a suitable source of vacuumv or low pressure so that upon the opening of valve 4 a vacuum may be created in chamber 20 and, through screen 24, within the container C to be filled. A second duct 31 communicates with chamber 20 and is provided with ya valve The latter duct extends to atmosphere so that upon Opening of valve 3 the chamber 20 and container interior will be coupled with atmospheric pressure.
A-pair of `ducts 32 and 33 are provided communicating with compartment 21 similar to the ducts 30 and 31 associated with compartment 20. Duct 32 is provided with a valve 1v interposed therein anda valve 2 is provided to control ow through duct 33. Duct 32 is coupled to a suitable source of vacuum or low pressure so that upon opening of valve 1 such low pressure will produce a vacuum in compartment 21 and within the container. Duct 33 is open to atmosphere so that upon opening valve 2 lthe compartment 21 and container interior will be placed in communication with atmospheric pressure.
Reference has been made tothe material feed inlet'tube 23 which in the illustrated embodiment extends downwardly through the center of the filling head 12; A control valve is provided in the flow'line of this tube so that opening-and .closing of valve'S may be employed toregulate the ,flow of material into the container to be filled. Aresi1ient seal element .35 is mounted on the underside of head 12 outwardly of the screens 24 and 25. This element encircles the screened area of the filling head and is positioned so as to overlie the upper edge of the mouth of the container C to be filled.
On Figure l container C is shown supported on rigid plate in the position for filling. An impervious bag liner L is illustrated positioned within the container with the open upper edge thereof overlapping the upper edge of the container mouth. A ring-like element 40 having a channel cross section'is supported on the upper edge of the container mouth and is provided with apertures 41 which communicate with conduits 42, perforated as shown at 43, and carried by element 40. The conduits 42 are provided at spaced points around the circumferenceof element 40 communicating at their upperendsby means of apertures 41 with the exterior of the container C. Accordingly, upon the pressure exteriorly of container C being reduced, air between the liner L and the inner wall of the container will be withdrawn through conduits 42.
It will be appreciated from the relationship of con tainer C, element 40 and liner L to the filling head 12, as shown in Figure l, that the upper open mouth of liner L which overlaps the upper edge of container Candelement 40 is clamped between the uppermost face of'. element .4,0 and thevresilient sealelement carried by filling head 12. This clamping of the open mouth of the liner L is effected when the lift plate 10 raises container C up into the filling position. The seal between the shroud 13 and lift plate 10 is also completed by the raising of the container into filling position.
The provision of a shroud 13 .to enclose the container which vis being lled performs Aa dual function in connection with the `ope'rationfo'f 'the instant invention. During the filling operation Ythe interior of the container is subjected to a relatively `high vacuum to assist'in drawing in the particulate material and also in withdrawing air entrained between the powder particles so that `a more dense compacted Afilling of the container may be achieved. Where the container walls are relatively thin and lack sufficient strength to resist such a high vacuum created within the container during filling, it is desirable to also `create ,a vacuum eXteriorly of the container to diminish thetpressure difference between the inside and outside of the container. Accordingly, shroud 13 provides a chamber in which `the container is positioned during filling, which chamber -is evacuated so that very little pressure difference exist-s between the pressure inside and outside the container during filling. A
The shroud 13 also provides a means for withdrawing air trapped between liner L and the inner wall of container C when the liner is loosely positioned within the container lfor -lling. Removal of such trapped air is facilitated by the provision of the ring-like element which carries the perforated conduits 42. It will thus be seen that upon reducing the pressure within the shroud 13 by opening valve 6, with valve 7 closed, the liner L will be sucked outwardly to lie in close contact with the inner wall of the container C. In this position the liner is disposed to receive a full complement of the particulate material as dispensed into the container through tube 23.
Where the structure of the container being filled is suffi ciently rigid to withstand the vacuum created within its interior during filling the container enclosing shroud may be omitted. Where the shroud is not provided, other suitable means may be provided to couple the perforated conduits 42 to a source of low pressure so that air may be withdrawn from between the liner and container wall through conduits 42 and element 40.
It will beappreciated that element 40 will have an annular configuration when employed with cylindrical wall containers so that the element can be supportingly engaged with the upper edge of the container. Likewise, Where the container wall has a configuration other than that of a cylinder, the element 4f) will be provided with a Aconfiguration generally conforming to the configuration of the container wall so as to be supported on the upper edge of the container wall in the manner as shown by the illustrated embodiment on the drawing. Likewise, the seal element 35 carried by the filling head 12 will be made to permit effective clamping of the liner mouth against the upper surface of the element 40 so as to preclude seepage during filling of material outwardly between the filling head and the impervious liner.
Having described in detail the structure of the specific embodiment illustrated by Figure l, reference will now be had to the method preferably employed in connection with filling through utilization of such apparatus. Preferably, the method of filling where relatively large containers are involved and wherein very finely divided material is to be dispensed into such containers will be in accordance with the generic method principles described and claimed in my co-pcnding application, Serial No. 490,942, filed February 28, A1955. Generally in the method of this prior applicatiomthe particulate material is dispensed into the receptacle in'separate individual increments with the pressure within the receptacle being continuously maintainedunder vacuum. By this method of filling, the vacuum, continuously existent over the material, tends to encourage withdrawal of air entrained between the powder particles while at the same time assisting in or eectin'g drawing of the material int'o the receptacle. It
has been found that this incremental lling, wherein a low pressure is maintained within the receptacle, results in very effective compacting or increasing of the material density so that the final quantity of material within the receptacle will be :substantially greater than that which could normally be dispensed into such receptacle by prior known methods.
Figure 2 on the drawing illustrates the relationship between the various valves during a filling operation wherein the hereinabove described apparatus is operated in accordance with the method of the instant application. As evidenced by the legend provided for Figure 2, the shaded blocks on the diagram indicate that the particular valve is closed while the unshaded blocks represent the valve in its open condition. The diagram is plotted against time so that each block represents one second in the filling cycle. It may be further pointed out that the two cycles shown on the diagram would not normally constitute a complete lilling operation but rather the cycles would be repeated in sequence a number of times until the container is completely filled.
The first column of the diagram lists the name designation of the individual valves and the second column lists the number given to each valve as applied to the structure shown on Figure l. The third column is provided to illustrate the condition of the various valves when at rest or prior to commencing a filling operation.
With the valves in the condition as shown in the column identified Start, the container C with the liner L positioned therein and element 40 supported on the upper edge of the container wall will be raised on plate up into the shroud 13 to assume a position as shown on Figure 1 of the drawing. At this time the valves 1 and 4 which control communication of vacuum with compartments 21 and 20, respectively, are closed while valves 2 and 3 which relieve the compartments 21 and 20 to atmospheric pressure are opened. Likewise, the valve 6 is closed and valve 7 opened so that the shroud interior exists at atmospheric pressure. At the same time the material valve 5 is closed.
Upon initiation of the lst cycle of the filling operation, valve 1 opens and valve 2 closes so that a vacuum is drawn within the container through screen 25. For the initial second of the lst cycle, valve 3 remains open thus permitting a momentary flow of air into compartment and through screen 24 as air is withdrawn through duct 32, compartment 21 and screen 25. This momentary flow of air through screen 24 serves to clean the screen of any powdered material that may have collected thereon in the last cycle of the previous filling operation. Valve 4 which controls communication of compartment 20 with the vacuum source and the material valve 5 remain closed during this initial portion of the lst cycle. As for the shroud control valves 6 and 7, valve 6 opens to initiate reducing the pressure exteriorly of the container C while valve 7 is maintained open for the first second of this lst cycle.
After the first second of the 1st cycle, valves 3 and 7 close and are maintained closed during the rest of the cycle. The closing of valve 3 terminates the ow of cleaning air through screen 24 and thereafter the pressure within the container and liner diminishes under the action of vacuum being applied through duct 32 with valve 1 open. At the same time, with the communication to atmosphere for the shroud cut olf by the closing of valve '7, the pressure within the shroud exteriorly of the container diminishes. As this pressure decreases, the air which may be trapped between the liner L and the inside wall of the container C is withdrawn through perforated conduits 42 so that the liner will be juxtaposed with the interior wall of the container. n
The opening of valve S which admits material into the container through pipe 23 is preferably controlled in response to the pressure within the container being filled. Thus, during the initial stage of the cycle, valve 5 remains closed. When the pressure within the container has decreased to the setting of the control for valve 5, the control is actuated and after a delay of one or two seconds the valve 5 opens to admit the powder to ow into the container through tube 23. As shown on Figure 2, the opening of valve 5 takes place after the fourth second of the cycle. The valves remain in this state for the remainder of the lst cycle during which time an increment of material Hows into the container so as to partially fill such container. As the increment flows into the container, air is withdrawn through screen 25, compartment 21 and duct 32. Such outow of air as powder Hows in through tube 23 causes powder to collect on screen 25 as filtered from the air being drawn out of the container.
After eight seconds the 1st cycle is terminated with an increment of material having been dispensed into the container. As the 2nd cycle commences, valve` 1 is closed and valve 2 opened. Valve 3 remains closed whereas valve 4 is opened to place compartment 20 in communication with the vacuum source through duct 30. With valve 2 open for the first second of the 2nd cycle, air flows into compartment 21 and back through screen 25 to reverse Hush the screen of any powder which collected thereon during the 1st cycle of the filling operation. The material valve 5 closes and does not there again open until after the pressure within the container has again been reduced to the point at which the control for valve 5 responds. This point of opening of the material valve is shown as occurring at about the fth second of the 2nd cycle similar to the response which took place during the 1st cycle. Valve 6 remains during the 2nd cycle while valve 7 is opened only for the first second of the 2nd cycle so that the pressure exteriorly of container C is diminished commensurate with the pressure drop within the container caused by the opening of valve 2.
The action which takes place in the 2nd cycle of the filling operation is similar to that which occurred during the lst cycle except that air is being withdrawn through duct 30, compartment 2t), and screen 24 by reason of valve 4 being open. Thus, in the 2nd cycle, when the material valve 5 opens, powder tends to accumulate on screen 24 as air is withdrawn from the container interior through duct 30. At the end of the 2nd cycle a second increment of powdered material will have been dispensed into the container. For the third, fourth and subsequent increments which are to be dispensed into the container to complete filling, the lst and 2nd cycles will be repeated in sequence until such time as the number of increments dispensed into the container lls such container to the desired degree.
It will be appreciated that the diagram of Figure 2 is merely exemplary of one particular valve timing relationship which may be employed and that in any specific case the time for opening and closing the various valves may vary from that shown on Figure 2. The size and therefore number of increments required to till the container with a desired weight of material may be varied depending upon the particular size container and/ or material which is being dispensed. For a particular size of container the density of the powdered material dispensed thereinto may be increased by employing a larger num ber of increments, thus operating with shorter cycles in the filling operation and likewise may be decreased by employing a longer cycle which results in fewer increments being required to lill the container. Also the magnitude of the vacuum used in the filling operation may be varied to give a lesser or greater density in the final product dispensed.
After the material to be transported by the container has been dispensed into the liner, the repetition of the 1st and 2nd cycles of the filling operation will be terminated and the valves returned to their condition as shown by 'aplacar 'the `colui-iin Start "on Ythe diagram of Figure 2. ,This vvillfreturn the pressure, bth within the container Iabove the material Vtherein and exterior-'ly of the container, to atmospheric pressure. Thereafter, lift plate 10 willbe lowered by means of cylinder 11 to remove container C `from within the shroud 13. The upper free end of liner 11 canthen be folded across the top of the material contained therewithin and sealed or otherwise closed to exclude the entrance of moisture into the impervious bag liner. A cover is then applied to the container C and such container prepared for transportation or storage as desired.
In `filling,ithe repetition of the cycles to complete a filling Operation will be set to fill the container with the desired weight ofvmaterial, with the sum total of the increments providing the desired degree of container fill as to weight and volume. Thus, it will be appreciated Athat for a particular size drum or open mouth bag container .the desired weight to be dispensed into the container will be employed in determining the number and density rof increments for which the machine will be set 'inperforming .the filling operation.
As shown `on the drawing the receptacle to be filled takes the lform of a rigid cylindrical walled drum con tainer C. It will be appreciated, however, that this illustration is merely by way of example and that within the scope of this invention the incremental filling method as Yset forth in the hereinafter appended claims may be `'employed in filling a variety of types of open mouth receptacles.
Having thus described my invention, what I claim is: l. A method of filling open mouth receptacles with finely divided particulate material employing a filling head having a pair of separate screened openings including lthe steps of withdrawing air from the receptacle to be filled through one screened opening to Yproduce a vacuum within the receptacle, admitting a limited quantity of air into the receptacle through Vthe other screened opening while continuing to Withdraw air through said one screened opening to maintain a vacuum within the receptacle, introducing an increment of material into the receptacle while ,continuing to withdraw air from the receptacle and from between the material particles to compact the material, withdrawing air from the receptacle through said other screened opening, admitting a limited quantity of air into the receptacle through said one screened opening while continuing to withdraw air from the receptacle and from between the material particles to compact the material, and repeating the above recited steps until the increments of material fill the receptacle to the desired degree.
, 2. A method of filling open mouth receptacles with finely divided particulate material employing a filling head having a-pair of separate screened openings including the steps of withdrawing air from the receptacle to be filled through one screened opening to produce a vacuum within l between the material particles to compact the material,
terminating the withdrawal of air through said one lscreened opening, withdrawing air from the receptacle through said other screened opening, admitting a limited quantity of air into the receptacle through said one screened opening while continuing to withdraw air through said other screened opening to maintain a vacuum within the receptacle, introducing an increment of material into the receptacle while continuing to withdraw air from the receptacle andsfrom between the material particles to compact the material, ,terminating the withdrawal of air through said other screened opening, and repeatingthe above recited steps -until` the increments of material fill the receptacle to the desir/ed degree.
3. KA infhd of f'fiIling open mouth receptacles Vhaving a iiexibleopen .top bag liner with finely divided particulate material and employing a filling head having a pair of separate screened openings including the steps of withdrawing air 'from betwen the wall of the receptacle to be filled and the liner to position the liner in juxtaposition with the receptacle wall, withdrawing air from the lined receptacle 'through one screened opening to produce a vacuum within the lined receptacle, admitting a limited 'quantityof air into the 'lined receptacle through the'other screened opening while continuing to withdraw air through said one screened opening to maintain a vacuum within .the lined receptacle, introducing an increment of material into the lined 'receptacle while continuing to withdraw air from the 'lined-receptacle and from between the material particles to compactthe material, withdrawing air Vfrom the llined receptacle through said other screened opening, admittingva limited quantity o f air into the lined receptacle through saidone screened opening while continuing to withdraw air from the lined receptacle and trombetween the ,material particle to compact the material, and repeating the above recited method steps two through six until the increments of material fill the lined receptacle to the 4desired degree.
r4. A method of filling open mouth receptacles having a flexible open top bag liner with finely divided particulate material comprising the steps of subjecting the space between the wall of the receptacle to be filled and the liner to a pressure lower than the pressure interiorly of the liner to open the liner and position it in juxtaposition with the receptacle wall, creating a vacuum within the lined receptacle, admitting material into the lined receptacle while continuing to maintain a vacuum within the lined receptacle, terminating the admission of material into the lined receptacle, relieving the vacuum widiin the lined receptacle, and thereafter closingT the open tops of the receptacle and liner.
5. An kapparatus 'for filling open mouth receptacles with particulate material wherein an impervious bag liner is disposed within the receptacle prior to filling which comprises a support member for holding the receptacle during the filling operation, a filling head positioned above said member to cooperate with the open mouths of the receptacle and liner to be filled, a material inlet carried by a said filling head, a ring-like element, a plurality of conduit means carried by'said element to extend downwardly therefrom to be disposed along the inner wall of the receptacle to be filled between such inner wall and the bag liner, said conduit means providing apertures adjacent the lower portion of the receptacle for withdrawal of air through said conduit means from between the inside wall of the receptacle and the bag liner, and means for connecting Vthe upper ends of said conduit means with a source of vacuum.
6. ln an open mounth bag lined container filling machine including a container supporting member and a 'filling head positioned thereabove with means for drawing a vacuum within the container through said head, a seal element carried by said head to cooperate with the mouth of the bag 'liner to preclude escape of material from around the mouth of the liner during filling, and a shroud carried by said head for enclosing the container during filling, the improvement which comprises a ringlike element having a configuration generally conforming a to the shape lof vthe open mouth of the container and supportable on the upper edge of the mouth of the container to be filled with the mouth of the bag liner overlapping the upper surface of said element, a series of conduit meansl carried by said element opening outwardly at their upper rends to the space exterior of the container and extending downwardly along the inner wall of the container between such wall and the bag liner.
7. A device for use with a machine adapted to fill open mouth containers employing a flexible bag liner comprising a ring-like element having a configuration generally conforming to the shape of the open mouth of the container to -be filled and supportable on the upper edge of the mouth of the container with the mouth of the liner overlapping the upper surface of said element, a seri-es of conduit means carried at peripherally spaced points on said element with the upper end of each of said conduit means communicating with the outer periphery of said element, said conduit means extending downwardly from said element so as to be disposed along the inner wall of the container when said element is positioned on the upper edg-e of the mouth of the container being filled, said conduit means providing apertures adjacent the lower portion of the container between the container and the bag liner to enable withdrawal of air through said conduit means from between the container wall and bag liner.
8. An apparatus for filling open mouth containers with particulate material wherein an impervious bag liner is disposed within the container prior to filling which comprises a support member for carrying the container during the lling operation, a iilling head positioned above said support member to receive the container to be lled between said support member and said filling head, a feed inlet tube carried by said filling head for dispensing material into the container carried by said support member, duct means carried by said filling head and having valve means therein for connecting the interior of the container being filled with a source of vacuum, a ring-like element having a configuration generally conforming to the shape of the open mouth of the container and supportable on the upper edge of the mouth of the container to be filled with the mouth of the bag liner overlapping said element, a plurality of perforated conduit means carried by said element to extend downwardly therefrom to be disposed along the inner wall of the container when said element is supported on the edge of the mouth of the container, said conduit means communicating at their upper ends with the exterior of said element, seal means carried by said lling head to clamp the portion of the bag liner which overlaps said element against the upper surface of said element, and means for connecting the upper ends of said conduit means to a source of low pressure whereby air will be withdrawn from between the container wall and the impervious bag liner to draw the liner into juxtaposition with the container wall.
9. An apparatus for filling open mouth containers with particulate material wherein an impervious bag liner is disposed Within the container prior to iilling which comprises a support member for carrying the container during the filling operation, a filling head having separate screened openings therein positioned above said support member to receive the container to be filled between said support member and said illing head, duct means communicating with said screened openings and having valve means therein for connecting the respective screened openings alternately with a source of vacuum and atmos pheric pressure, a feed inlet tube carried by said filling head and having a valve therein for controlling the admission of particulate material into the container to be filled, a ring-like element having a configuration generally conforming to the shape of the open mouth of the container and supportable on the upper edge of the mouth of the container to be filled with the mouth of the bag liner overlapping said element, a plurality of perforated conduit means carried by said element to extend down wardly therefrom to be disposed along the inner wall of the container when said element is supported on the edge of the mouth of the container, said conduit means being in communication at their upper ends with the atmosphere exterior of the container, a shroud interposed between said plate and said filling head to provide a cham]- ber enclosing the container to be filled, duct means communicating with the interior of said shroud and having valve means therein for connecting the shroud interior -alternately with a source of vacuum and atmospheric pressure whereby air will be withdrawn from between the container wall and the impervious bag liner upon reduction in pressure within the shroud to draw the liner into juxtaposition with the container wall, and seal means carried by said filling head to clamp the portion of the bag liner which overlaps said element against the upper surface of said element.
References Cited in the le of this patent UNITED STATES PATENTS 2,565,045 Ray Aug. 21, 1951 2,678,764 Carlson May 18, 1954