US2886072A - Bag packing machine - Google Patents

Description

May 12, 1959 J. M. HOFF 2,886,012

BAG PACKING MACHINE Filed Aug. 1s, 195e 2 sheets-shan 1 Setthng Siohon Bog Aftuchmg Sintion Bag Removal Station MaylZ, 1959 .1. M. HoFF BAG PACKING MACHINE Filed Aug. 115. 1956 2 Sheets-Smet 2 COQ Fig. 4.

Charging Station Bug Attaching 7 I A Y station IMEATOR.

Jeun M. Hoff Bag Removal Station Fig. 3.

TTORNEY' BAG PACKING MACHINE Jean M. Holi, Wyandotte, Mich., assgnor to Wyandotte 'ChemcalsCorporatiom Wyandotte, Mich., a corpora tion ofMichigan ApplicationAugust 13, 1956, Serial No. 603,598

6 Claims. (Cl.` 141-59) This invention relates tota bag packing machine. More especially it relates to a bag packing machine adapted for illingvalve type bags with low density, nely divided, easily uidized materials.

Low density, powdery materials such as` ultraiine calcium carbonate, carbon black, `flour andthe like, are readily suspended in air las dust. Consequently, it is customary in :the artto package such materials in valve type, closed end, paper bags. Such bags are completely closed at both" ends `except `for a small` infeed `opening at one corner, which is provided witha apper valve that covers the openingwhen the bag contents rest against it. To iill such` a bag, the bag is thrusttonto a horizontally disposed filler spout with the spout passing through said infeed opening and the materials to be bagged is passed through` the charge port of the spout. Thus, such: bags tend to `minimize dust loss` although enough dust may escape in shorts from between the infeed `opening and the `filler spout to required dust collection equipment.

Besides their ability to form dust, low density, powdery matexialshave a tendency` to entrap air within their interstices and become somewhat fluidized or expanded in apparent `volume per given Weight of material. Indeed such materials may be` intentionally fluidized to facilitate their introduction into bags. In order that a given bag of. material might contain a proper, conventional ultimate weight ofimaterial `it is therefore necessary, when bagging such materials with conventional bag iilling equipment, to use extra large bags.

In mostcommercial operations,` the bags, after being `filled,` are inan apparently compact and firm condition,

and, in` this condition,-they are stacked on their sides p on a pallet. After lan appropriate number of bags have 4accumulated `to make a` load, the pallet is then conveyed by a lift truck; tor a warehouse `for storage or to a box c-ar or the like for `transportation probably to a place of storage. period of time, which might be considerably shortened where the bags are subjected to a substantial amount of jigglingin` the course of transportation, the entrapped air percolates out of the interstices of the particles and eventually outofteach bag, leaving each bag in a loose, abbycondition `wherebytthe` pallet of ybags tends to lose Shape, sag, and sometimes tumble, resulting in an untidy storage condition as well as a substantial loss of storage space.

Thus, the `art has been faced with the problem of tinding ways and means` to avoid dust losses, to avoid the use` ofextra large bags and to avoid the disadvantages of defluidization.

One lapproach the `art has taken to this problem is to ll the bags in a vacuum so that as the material descends into the bags, the pressure-diiierential between `air in the material and the ambient pressure causes the entrapped air `to escape from the interstices of the particles of material `and be removed. There may be some dust productionbut inthis type of operation the dust Understorage conditions, over a` ICC can .be conned to the bag or to the machine and in the latter case collected with conventional dust collecting equipment.

Vacuum bag packing machines are known, the most advanced of which is exemplied by U.S. Patents, No. 2,687,271 and No. 2,720,375, to C. F. Carter. The Carter machine is characterized by an airtight, bag llling` chamber and a complicated sequence of operations which involve opening the shroud enclosing the chamber in order to p-lace an empty bag inside, evacuating air from the chamber, filling4 the bag bytsucking in material, opening the shroud, and then removing the bag therefrom. To perform these operations automatically, not only a complex mechanism required but such a mechanism has a tendency to give to these machines low bagging rates. In addition, bag filling machines of this type construction have a disadvantage in that vacuum is applied in the bag filling chamber to the seams and corners` of thebag whereat the bags arethe weakest and are most likely to burst or leak; i

It is therefore a general object of this `invention provide the art with an improved vacuum type, bag packing machine.

More especially, it is an object of this invention to provide the art with an improved vacuum type, bag packing machine adapted for use with valve type bags, which machine is capable of high bagging rates.

A specific object of this invention is to develop` a vacuum type, bag packing machine for lling valve type, multi-walled paper bags with low density, powdery, fluidized materials and obtaining compact, permanently firm bags under substantially dust-free conditions.

Another specific object of this invention is` to obtain a vacuum type, bag packing machine in which vacuum is `applied only to the sides of each bag.

These objects and other objects which may appear as this specifi-cation proceeds are achieved by this invention which is based on the principle that `the walls of valve type paper bags are permeable to air but not to powdery materials within such bags.

In summary, this invention involves a vacuum type, bag packing machine comprising means for supporting a valve type, multi-walled paper bag in a bag filling position, means for inflating the bag, means for introducing a weighed charge of low density, powdery material into the inflated bag, means for removing air from the interior of the bag through one of its air permeable side walls and thus from the interstices of the bag contents,

which means comprise a pair of plates spacedly set apart i the Width of the filled bag and adapted with means to apply suction to substantially the entire area of at least one of the air permeable side walls of the bag.

A preferred embodiment of this invention comprises a bag hanger arm, arranged horizontally, stationed between two oppositely disposed suction panels and adapted to pass through the infeed openingof a` valve type, paper bag and to support the pasted or sewn infeed end of the bag when it is placed in position thereon. The suction panels are adapted and provided with means for applying suction to substantially the entire area of both side walls of a bag supported on the` .bag hanger arm. Preferably, the hanger arm has at one end thereof a bag illerspout opening which is arranged to be within the bag supported by the hanger arm and through which is first introduced pressurized air to inflate the bag and thereby cause its side Walls to engage the suction panels and then a weighed charge of bag lling material.

The operation of the bag lling machine is sequential in nature, comprising the essential steps of (1) inflating the empty bag with pressurized air while simultaneously apply-ing air suction to the side walls thereof by means of the suction panels; (2) introducing a weighed charge of material into the bag while applying suction to the sides of the bag; and (3) disrupting the suction to the side walls of the bag and removing the bag.

In this preferred embodiment the ller spout opening may be the outlet of a feed hopper into which the charge of weighed materials is dropped for introduction into the empty bag on the hanger arm. Indeed, when dealing with finely divided materials having a high angle of repose, this hopper may be of advantage because of the fact that such materials have a tendency to move rather slowly through the ller spout opening even though fluidized. Therefore, particularly when dealing with such materials, the suction should be applied at least at intervals until all of the charge has entered the bag. As' a matter of fact it may be desirable to interrupt the suction at predeter* mined intervals, particularly where such materials are of such iineness as to blind the pores in the side walls of the paper bag. Such interruptions not only tend to keep kthe pores open and free but also to compact the material in the bag and to prevent inward dimpling of those portions of the bag not in contact with the suction plates. Further and more rapid compaction of the materials in the bag can be obtained by providing means for vibrating the bag either continuously or at a particular step in the bag filling operation either in or out of phase or bothl with the application of suction through the suction panels.

The extent of interruption and application of suction to the bag and the application of vibration to the bag depends almost entirely on the materials being bagged and the materials of construction in the bag. This aspect of the invention, however, is not critical and with the teachings of this specification in mind can be worked out in any given case by those of ordinary skill in the art.

A further feature of advantage is that at the packed bag removal step in the operation of the machine of this invention, pressurized air can be applied, preferably as a short but strong blast, through the suction panels to the packed bag to impel the bag in the direction of removal. This also assists in disengaging the suction panels from the packed bag. Other means, such as an air actuated piston, may be used to impel the packed bag in the direction of discharge.

The machine of this invention may comprise a single bag filling station or a number of bag filling stations at which all of the steps are performed. In such case means are provided for -automatically supplying pressurized air and vacuum at predetermined steps in the bag lling and compacting operation.

The machine of this invention may also comprise a number of assemblies comprising a hanger arm and a pair of suction panels which pass from one station to another whereat one or more steps of the bag filling and compacting operation are performed. In a preferred embodiment of this invention the machine is provided with a number of bag hanger arms associated with a rotatable plate and associated with the same number of pairs of suction plates travelable with the bag hanger arms. The rotatable plate is provided with means for supplying pressurized air and vacuum to the suction panels and with a hopper and filler spout in association with the hanger arm. Adjacent the rotatable plate is a stationary plate provided with pressurized air distributing means and vacuum distributing means which are positioned in relaton to the rotatable plate and adapted so that as the rotatable plate rotates, pressurized air and suction are respectively supplied to the ller spout and suction panels at the bag attaching and inilation station, vacuum is supplied to the panels at the bag charging station, pressurized air is supplied to the panels at the bag removal station, and predetermined air pressures (pressurized air and vacuum) are applied at any of the intermediate bag settling stations that may be provided.

Before turning to the drawings, it should be understood that this invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, wherefore, the embodiment to be described is illustrative and not restrictive inasmuch as the scope of the invention is defined by the appended claims rather than by the description preceding them, and all changes that fall within the metes and bounds of the claims or of forms that are their functional as well as conjointly cooperative equivalents are therefore intended to be embraced by those claims.

Referring to the drawings, it will be observed that Fig. 1 is a plan view of a preferred embodiment of a vacuum type bag packing machine of this invention;

Fig. 2 is a cross sectional side view of this machine, taken along the lines 2-2 of Fig. 1;

Fig. 3 is a plan view of the machine taken along the lines 3-3 of Fig. 2;

Fig. 4 is a sectional view of a bag filling station of the machine, which view has been taken as along the lines 4-4 of Fig. 3; and

Fig. 5 is a bottom view of the stationary upper plate taken along the lines 5-5 of Fig. 2.

In somewhat more detail, the drawings illustrate a bag filling machine 10 having a rotatable turntable 12 of the indexing type and a stationary base 14 provided with means (not shown) for rotating the turntable. At the center of the rotatable turntable and embedded in the stationary base is a stationary, vertically disposed, tubular center post 16 at the upper end of which is mounted a generally circular, stationary upper plate 18. The center post 16 is concentrically arranged within a rotatable. vertically disposed cylindrical shaft 20. This rotatable shaft is associated with a generally circular, rotatable lower plate 22, the upper surface of which slidingly contacts the lower surface of the stationary upper plate 18.

Arranged in circular alignment and equidistant from one -another about the rotatable lower plate 2.2 and hanging downwardly therefrom are a number of hoppers 23, each of which is provided at the top with an infeed opening 24 in the rotatable lower plate 22 and a discharge outlet 2S at the bottom which is associated with a ller spout 26, having -a charge port 27 located on the under side of a bag hanger arm member 28 and in position to be inside a valve type bag hanging from said bag hanger arm member. The hanger arm member 28 is adapted with a iive degree downward slope and has as its purpose the supporting of valve type, multi-walled paper bags 29 such as shown in outline form in Fig. 2.

These bags are well known in the art and are described, for example in the U.S. Patent, No. 2,720,375, to Carter, in column 3 at lines 55-61. From this description, it can be seen that the bag is suspended from the hanger arm member by inserting the hanger arm member through the valve opening of the bag and sliding the bag on the arm until the valve iller spout is reached. The filler spout 26 of the machine of this invention should be large enough on its outside to completely occupy the valve opening of the bag to thereby prevent dust losses and to make the most efficient use of pressurized air and vacuum during the bagging operation.

Below each of the bag hanger arm members 28 is a platform 30 supported by a platform base 32 which may comprise a vibrator means. The platform base is attached to the rotatable turntable 12.

On each side of the platform 30 and connected thereto is a rectangular shaped suction panel 34 arranged parallel to its opposite member and spaced apart from its opposite member by the approximate width of a lled and compacted bag. It will be observed that each suction panel is provided with a number of grooves 36 arranged in a circular, crisscross, and rectangular configuration to distribute the suction forces over substantially the entire area of each of the side walls of the bag 29. Surrounding the configuration of suction grooves 36, and adjacent the rectangular periphery of the suction panel 34 is a continuous sealng'groove 38 which functions when a `bag is in place and at full size to minimize the passage of air from about the end of the panel along the inside surface of the panel to the suction grooves 36. The suction grooves 36 communicate with each other and with a port 40 positioned in the center of the suction panel 34 and connected to a conduit branch 42 from feeder conduit 44 which leads to an inlet opening 46 in the rotatable lower` plate 22. This inlet opening 46 is positioned in the rotatable lower plate in a. circle of similar openings, each of which is spaced an equal distance from its neighboring openings. Coincident with the circle of inlet openings 46 is a semicircular vacuum distribution channel 48` grooved in the surface of the stationary upper plate 18 and provided with a blanking piece 49, the function of which will be more fully described hereinafter. Communicating with the vacuum distribution channel 48 is a vacuum supply conduit 50 provided with a valve 51 for controlling the degree of vacuum to be applied to the channel 48 and thus to each of the suction panels 34.

The stationary upper plate 18 is also provided with a pressurized air inlet 56, which is stationary in circular alignment with the vacuum distribution channel 48 so as to be in circular alignment with the inlet openings 46 of the rotatable lower plate 22. Said pressurized air inlet 56 is associated with a pressurized air conduit section 58 which has a Valve 59 for controlling the supply of pressurized air to the suction panels 34.

Disposed in the stationary upper plate and in ci-rcular alignment with the inlet openings of the hoppers 23 is a pressurized air inlet 52 which is associated with a pressurized air conduit section 54 having a valve 55 for controlling the passage of pressurized air therethrough. The inlet 52 is radially positioned with reference to the leading end of the vacuum distribution channel 48 and both this inlet and the leading end of the vacuum distribution channel are located at the bag attaching station of the apparatus.

Both pressurized air conduit sections 54 and 58 branch o from a pressurized air supply conduit 60 which has a valve 61 for controlling the over-all supply of pressurized air to the apparatus.

Situated on top of the Istationary upper plate is a feed chute 62 having la discharge outlet 64 in the stationary upper plate, which outlet is positioned at the charging station of the apparatus in alignment with the inlet openings 24 of the hoppers 23. Although it can be made smaller than the hopper inlet openings 24, it is preferred that the discharge outlet 64 be at most the same size and shape as the hopper inlet openings. The feed chute 62 may comprise the discharge chute section of a charging and weighing device such as disclosed in the aforementioned Carter patents.

The operation of the apparatus just described can be summarized in somewhat the following manner.

At the bag attaching station of the apparatus a valve type, multiwall bag is thrust either by automatic means or by hand on the bag hanger arm member 28. Because vacuum is applied through the vacuum distribution channel 48, feeder conduit section 44 and thus the suction panels 34, and pressurized air is charged preferably as a blast into the hopper inlet 24 from the pressurized air inlet 52 in the stationary upper plate 18, the bag becomes inliated to its ultimate size and the side walls of the bag contact the suction panels 34 and are held thereto by the suction. To keep the pressurized air passing into the bag from overloading the vacuum supply system, the air valve 55 may be manually or automatically opened for `a short period of the time interval for this step to admit a blast of air to the bag and/or the portion of the vacuum distributing groove 48 supplying vacuum to the bag attaching station may be constricted.

The 'hopper inlet 24 is then in register with the feed chute outlet 64 and, at this point, a weighed charge of material is dropped through the feed chute 62 into the hopper 23. Meanwhile, vacuum is being continuously applied through thedistribution channel 48 into the feeder conduit section 44 and thus to the suction panels 34. This assists in drawing the weighed charge of material through the hopper outlet 25 and liller spout inlet 27 into the bag and functions to expel air from the interstices of the particles of material being charged into the bag.

The rotatable turntable 12 is then moved into the next position whereat vacuum is still applied to the suction panels. This station has been referred to in the drawings as settling station A. At this station the vibrator in platform base 32 is operated to assist in settling the materials in the bag and in the percolation of air from the interstices of the materials.

The turntable 12 is then rotated to the next position whereby the bag is brought to settling station B. At `this station, because of the blankng piece 49 closing off that portion of the vacuum distribution channel 48 which would be in register with the inlet 46 of the feeder conduit section 44 at that station, there is no vacuum applied to the suction panels 34 at that station. This is an optional step and is preferably done because in a number of instances material may not ilow into the bag fast enough at its charging station to prevent the bag from dimpling inward at places` along its gusset. This can be counteracted by using a cycle wherein vacuum is applied to the bag for a period of time and then released, followed by vibrating the bag to mechanically settle the material and force out the dimpled in spots. Hence, in this particular instance, the vibrator in platform base 32 at the settling station B is also operated.

Another reason for discontinuing the vacuum at settling `stat-ion B is that continual application of vacuum tends to cause particles in the bag to blind the pores of the paper bag. Disruption of the vacuum breaks loose those particles blinding the pores.

The rotatable turntable 12 is again rotated one more position whereby the bag is at settling station C whereat vacuum is again applied through the conduit section 44 from the distribution channel 48 to the suction panels 34. lt is at this station that the bag is finally compacted and made firm.

The rotatable turntable 12 finally is rotated another position whereby the compacted, rm bag is brought to the bag removal station. At this station pressurized air is introduced into the inlet of the feeder conduit section 44, preferably as a blast, and passes therethrough into the suction panels 34 whereby the suction is broken and the bag thus made ready for manual or automatic removal.

This latter operation can be substantially facilitated by pointing the conduit branch 42, where it joins the port 40 of each suction panel, in the direction of bag removal whereby blasts of air passing therethrough tend to impel the packed bags in the direction of removal.

Although the foregoing apparatus has been described with a rotatable turntable of the indexing type, it will be realized that a rotatable turntable of the continuous type can be used.

The number of stations of the machine are dependent for the most part on the local conditions. ln the particular embodiment shown there are three settling stations. The number, however, is not critical insofar as this invention is concerned and can be varied to suit. the local conditions. Moreover, the operating cycle of the machine can be easily changed by positioning the pressurized air outlets and vacuum distributing grooves to register with the outlets of the feeder conduit lines to the suction panels at any desired station and step of operation.

It is expected that the bags may be removed manually or be pushed off with an air cylinder which could be con- :7 nected to the feeder conduit section 44 leading to the suction panels 34. This latter means of removing bags from the machine is shown in the Carter patents previously noted herein.

The machine of this invention offers a number of advantages. In the first place it is practically dust free in operation. Secondly, it enables the bags to be filled with the proper weight of materials and then compacts the materials in the bags. The machine has a large capacity or high bagging rate. In addition, bag size of the bags used with this machine is now dependent only on the deiluidized volume of the solids to be packed. Finally, the machine of this invention is readily adapted to local conditions and under local conditions offers flexibility of operation.

What is claimed is:

l. A bag filling machine for filling valve type paper bags with readily liuidized materials, which comprises a horizontally disposed, rotatable turntable connected to a rotatable, upright center shaft; means for rotating said turntable and shaft; a rotatable, horizontally disposed plate above said turntable and associated with said rotatable shaft; a number of hoppers suspended from said rotatable plate with the inlets thereto disposed in a circle about said plate; at the discharge end of each of said hoppers a filler spout for valve type bags; for each filler spout a pair of suction panels mounted upright and in association with said turntable, said suction panels being oppositely disposed with said filler spout in between, said panels being spacedly set apart by the approximate ultimate width of a packed bag, and the opposing faces of said suction panels being adapted with grooves arranged in a conguration to communicate with one another and to apply suction to substantially the entire side wall area pf the bag in contact with said panel; a stationary plate in sliding contact with said rotatable plate, provided with a feed chute, the outlet of which is in circular alignment with the inlets of said hoppers, and provided adjacent said rotatable plate with a semi-circular suction distribution groove connected to a source of suction and disposed adjacent said feed chute; and conduit means in communication with said grooves in said suction panels and with inlets in said rotatable plate, which are in circular alignment with said semi-circular suction distribution groove.

2. A bag lling machine according to claim l wherein .said stationary plate comprises a pressurized air inlet in circular alignment with, and adjacent to the trailing end of, said semi-circular suction distribution groove and in alignment with said inlets to said conduit means, the position of said inlet corresponding to the bag removal station of said machine, said pressurized air inlet being connected to a source of pressurized air.

3. A bag filling machine according to claim 2 wherein said conduit means are angled in the direction of bag removal at the juncture thereof to said grooves of said suction panels.

4. A bag filling machine according to claim 1 wherein said stationary plate comprises a pressurized air inlet in circular alignment with, and in advance of, said feed chute with said inlet being connected to a source of pressurized air.

5. A bag filling machine according to claim l wherein for each pair of suction panels there is a platform resting on said turntable and provided with vibrator means.

6. A bag filling machine according to claim 1 wherein each suction panel is provided with a continuous sealing groove positioned adjacent the periphery of said panel.

References Cited in the le of this patent UNITED STATES PATENTS 2,565,045 Ray Aug. 21, 1951 2,780,247 Claassen Feb. 5, 1957 2,783,786 Carter Mar. 5, 1957

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