US20130019571A1

US20130019571A1 - Methods and apparatus for high-speed pouch-filling

Info

Publication number: US20130019571A1
Application number: US13/552,770
Authority: US
Inventors: Mark R. Nease
Original assignee: Oystar North America Inc
Current assignee: Oystar North America Inc
Priority date: 2011-07-20
Filing date: 2012-07-19
Publication date: 2013-01-24

Abstract

Bandoliers of serially-connected four-seam pouches are received, opened and filled in continuous motion on a rotating parallel land high capacity filler wheel with a tucker finger engaging the bottom seam of each pouch to facilitate the opening process, and where the pouches are held solely by the lands without other pouch engaging or holding clips or other structures.

Description

BACKGROUND OF THE INVENTION

Filling pouches is an industrial manufacturing task in which attaining higher speeds without reducing fill consistency is a constant goal. One mechanism for filling pouches involves taking a web of pouches, usually defined by connecting two plies of sheet material with seams at regular intervals, and bringing the so-called bandolier web to a filler wheel to sequentially fill the pouches along the web. The sheet material may be plastic, cloth, paper, or any suitable material.
There exist two different constructions for a bandolier-type web of pouches. A three-seam pouch is made of a single sheet of web material which is folded to form both plies, with the fold acting as the bottom of the pouch. Side seams are formed at regular intervals by transverse seals across the two-ply web and a top seam is sealed after filling. Such three-seam pouches therefore lack a bottom seam and, rather, have a bottom fold. A four-seam pouch may use two separate webs for its plies, connecting the webs with a sealed bottom seam as well as sealed side seams and a top seam after filling. Such a four-seam pouch is known. For both three-seam and four-seam pouches, the top of the pouch is open during the filling process, and is sealed after the pouch is filled. Such webs are also referred to as a pouch bandolier, a line of serially-connected or entrained pouches, and other terms of art which are herein understood to be synonymous with the aforementioned web. For both three-seam and four-seam pouches, the seams may represent heat seals, stitching, adhesive, or any other means or combination of means for connecting two plies of sheet material at the locations of the seams.
At least two forms of filler wheels are known in the art for bandolier-type pouch webs. In one, known as a tapered land filler wheel, the pouch supporting lands mounted about the filler wheel are inclined upwardly and inwardly with respect to the vertical wheel axis. Specifically, the upper ends of lands are inclined toward the axis and lower ends away from the axis, tilting the lands inward along the circular wheel. The result of this geometry is that the lands under the pouch side seams at the lower ends are spaced apart a first distance defining a chord between the lower land ends about equal to the pitch of the closed or flat pouch. At the upper end, and as a result of the inward taper, the distance between the lands at the upper end are at a second distance or chord less than the first distance or chord between the lands at the lower end. This reduction allows the mouth of the pouch, at the upper end, to open (i.e. the seams at the upper pouch end being closer together than at the lower pouch end). Thus, the pouch can be filled with a spout extending into the open mouth.
Additional features may be included to aid in opening and filling each pouch. For example, vacuum cups between the lands, air jets, and over-driven rollers may each help to “pop” the pouch open. Further teachings related to a tapered land filling wheel can be found in U.S. Pat. No. 3,821,873 to Benner, Jr. et al., which is hereby incorporated by reference as though included herein in its entirety.
The speed of a tapered land filler wheel can be potentially increased by enlarging the diameter of the wheel and increasing the number of stations around the wheel, thus increasing the available fill time of the pouches on the wheel and overall speed. However, there may be a floor plan or footprint or various other reasons limiting wheel diameter enlargement. Moreover, due to the geometry of the tapered land filler wheel, increasing the number of fill stations for any given wheel diameter reduces the pouch mouth width for each station. If the number of pouch stations (lands) is simply increased on the same diameter wheel in order to increase through speed or line speed, the geometry is such that the chord reduction at the pouch mouths decreases, resulting in smaller and smaller mouth openings until the openings are too small to receive a spout for accurate filling. Accordingly, increasing line speed for pouches in such inclined land equipment quickly reaches an upper limit due to the geometric limitations of the system.
Due to geometry constraints, tapered land filler wheels can create only a finite amount of pouch width reduction for mouth opening, usually about 5%-8%. The more mouth width is reduced, the smaller the mouth and cooperating spout and the slower one can achieve the desired flow rate of fill material. When the restriction is smaller, the achievable fill speed is slower. Moreover, for any given pouch size, as the diameter of a tapered land filler wheel increases (in order to correspondingly increase the number of stations), the possible pouch width reduction decreases and an operational limit is reached. The effects on reduction discussed above are a function of the geometry.
Historically, four-seam pouches have been filled using tapered land filler wheels, which, due to the difference in chord length between the top and bottom pouch surfaces, can provide reduction to the pouch opening without disturbing the bottom seam of the pouch.
In another type of filler wheel for three-seam bandolier-type pouches presented, known as an increased capacity filler wheel, the pouch stations around the periphery of a filler wheel are defined by a plurality of parallel pouch seam lands disposed in parallel to the vertical axis of the wheel. In contrast to the tapered lands described above, these parallel lands can impart the same width reduction along the entire height of the pouch. However, a tucker, such as a tuck finger, tuck paddle or the like is located between respective pouch lands at the lower end thereof to engage and push up the folded pouch bottom toward a more cylindrical pouch configuration for filling.
Additional features, such as vacuum lands, air jets, and over-driven rollers, may aid the opening and filling process as above. Further discussion related to this type of filler wheel may be found in U.S. Pat. No. 4,232,504 to Dieterlen et al., which is hereby incorporated by reference as though included herein in its entirety.
Such increased capacity filler wheels have generally provided for higher fill volumes, even as speeds increase. Because the reduction is not based on the diameter of the filler wheel, an increased capacity filler wheel can easily accommodate a pouch width reduction of as much as about 18%-22% independent of the number of lands used.
Historically, use of increased capacity filler wheels has been limited to three-seam pouches. Conventional wisdom holds that these wheels cannot be used with four-seam pouches, since the lower seam flange or margins were believed to stiffen or rigidify the pouches at their bottom. When manipulated or tucked to cause pouch deformation, the added stiffness at the bottom seam resulted in inconsistent deformation and pouches could not uniformly be filled. This would render the system ineffective at increased speeds for such four-seam pouches.
More particularly, four-seam pouches were understood to not be suitable for increased capacity type filler wheels for three seam pouches because the relatively rigid bottom seam would not fold well or because it would wrinkle, sometimes inwardly and sometimes outwardly when engaged by the tucker. It was also believed that the upward motion of the tucker would tend to push the pouch up and off the vacuum lands, also due to the increased stiffness produced by the sealed bottom seam.
The concept of the increased capacity filler wheel is to create the pouch width reduction by having parallel vacuum lands smaller than the width of the unopened pouch. When running three-seam pouches, a tucker paddle raises up to make contact with the pouch; the bottom (being a fold and not a rigid seam) conforms to the shape of the tucker. Because the bottom seam in a four-seam pouch does not have the flexibility of a bottom fold, it was believed that four-seam pouches would not consistently open or conform to the tucker during high-speed filling. As will be described, the prior art teaches that when four seam pouches are thus handled, such an apparatus requires additional pouch holding or supporting mechanisms such as clips.
Conventional tapered land and increased capacity fillers typically run at speeds up to approximately 4000 inches of web per minute.
Accordingly, it is nevertheless desired to provide a high line speed apparatus and method for filling a web of four-seam pouches at greater speeds, for example, at speeds of 5000 and 6000 to 7000 inches per minute or more, and without any pouch holding structures other than the filler wheel vacuum lands.
In yet another form of pouch filling and sealing processes, three-seam pouches are formed in a bandolier configuration, but are cut or separated one from the other, before separate introduction to sets of pouch-edge grippers on a filler wheel where the separate pouches are filled, then sealed. U.S. Pat. No. 7,954,307 is expressly incorporated herein as illustrating that process and apparatus for background only.

DESCRIPTION OF THE DRAWINGS

These and other advantages will become readily apparent from the following detailed description of the drawings in which:

FIG. 1 is an isometric view of a single four-seam pouch in closed or flattened condition with the mouth in slightly open position shown in phantom;

FIG. 2 is an isometric view of a train or integral bandolier of four-seamed pouches as in FIG. 1;

FIG. 3 is a combined top plan view comparing a single flattened pouch of FIG. 1 to the same pouch, but as opened, when disposed on a filler wheel;

FIG. 4 is a diagrammatic plan view of a filler wheel and bandolier pouch web disposed therein;

FIG. 5 is a cross-sectional view through the filler wheel of FIG. 4 taken along lines 5-5 of FIG. 4;

FIGS. 6 and 7 are fragmentary, diagrammatic top plan views illustrating the sequence of positions of a four-seam pouch web as it moves onto the filler wheel;

FIG. 8 is a side elevational view in partial cross-section taken along lines 8-8 of FIG. 7;

FIG. 9 is a fragmentary cross-sectional view illustrating the raised position of one tuck finger and clamping clip; and

FIG. 10 is a side elevational view taken along lines 10-10 of FIG. 7.

DESCRIPTION OF THE INVENTION

To these ends, the invention contemplates continuously running four-seam bandolier pouches on a filler wheel of the increased capacity type, with parallel vacuum lands. Contrary to conventional wisdom and surprisingly, it has been found that the tucker at the bottom ends of the lands engages the bottom seam of the pouch and urges the pouch bottom upwardly into a consistent pouch configuration that is suitable for filling, even for four seam pouches without the need for any clips or other pouch holding devices other than the vacuum lands. High line speeds of about 5000 and 6000 to about 7000 inches per minute, and greater, are realized by solving the problems otherwise associated with increasing the filler wheel diameter for more pouch time on the wheel and increasing the size of the pouch mouth opening, as further described herein.
Thus, this invention combines the four-seam bandolier pouch web on one hand with the increased capacity filler on the other hand and despite the otherwise conventional wisdom and prior art teachings that such four-seam pouches could not be consistently handled at high speeds on an increased capacity filler and, in any event, would require pouch holding clips.
In attempting to exceed the conventional 4000 inches per minute rate, two problems must be solved. First, it is desired to create a larger diameter filler wheel to maximize filling time. Second, the filler spout size must be maximized in order to maximize flow rates of the fill material which, in turn, requires maximizing the size of pouch openings.
A primary factor for increasing opening size of each pouch is the pouch width reduction afforded by the spacing of the vacuum lands. Since tapered land filler wheels cannot practically achieve reductions higher than approximately 8%, an increased capacity filler wheel having parallel transverse sealer lands was used in the invention instead.
As shown in the figures, an increased capacity filler wheel may include vacuum lands as will be described, each of which is disposed parallel to the axis of the filler wheel and spaced to accommodate and hold the side seams of adjacent pouches, slightly closer together than their distance in a fully-flattened pouch. Tuckers (also referred to as tucker fingers or paddles) move upwardly to exert a shape-deforming force upon the bottom of the pouches. Static mounted tuckers may be used. The bottom of each pouch responds to the tucker by taking on a shape that facilitates opening the top of the pouch. Once open, fill material passes through filler spouts to fill each pouch. The pouches then leave the filler wheel to proceed to the next station in the manufacturing process. Subsequent stations may seal the opening at the top of the pouches, as well as cutting, collating, or further packaging the four-seam pouches as known in the art.
As shown in the figures, tucking rollers and air jets assist the vacuum lands and tuckers in opening each pouch. Further features facilitating high-speed fill will be recognized by persons skilled in the art of being compatible with methods of the present invention.
It is appreciated that while the prior art teaches that pouch-holding clips are required for stiff bottom or four seam pouches, according to the prior art, this invention contemplates four seam pouches supported exclusively by the vacuum lands and without any clips or additional pouch supporting structures.
As one exemplary embodiment of the present invention, a web of four-seam pouches was successfully run through an increased capacity filler wheel at speeds of up to 7000 inches per minute. It was determined that the bottom seam did in fact wrinkle inward or outward when engaged by the tucker, but that the device was nonetheless able to control and open the pouches for filling consistently and without any pouch holding clips. It was also found that the tuckers can be configured to make only light contact with the pouch bottoms, thus preventing the tuckers from pushing the pouches off the vacuum lands.
To allow for higher filling speeds, the exemplary embodiment also included an increased capacity filler wheel with more stations. These extra stations not only allow for more filling time of a pouch on the wheel, but also provide more time to use air jets to blow open the pouch. The extra space on the filler wheel allowed the use of longer air nozzles to aid in opening the pouches prior to filling.
In deference to the concerns associated with filling a four-seam pouch web using an increased capacity filler wheel, the selected vacuum land spacing resulted in a pouch width reduction of approximately 8%-10%. This resulted in a bigger pouch opening than was possible with the smaller reduction afforded by the tapered land filler wheel. That allowed for a bigger spout on the one hand for better flow of fill material, and also allows for a bigger mouth target for the spout to enter the pouch, making the pouch opening a little less sensitive. This helps to alleviate some of the problems mentioned above.
In the described embodiment, it was also found that the combination of the bottom seam with the increased capacity filler wheel created a pouch opening shape that was different than normal. An increased capacity filler wheel used with three-seam pouches normally produces a pouch opening with an oval shape. In the exemplary embodiment, the opening of each four-seam pouch was more diamond shaped. The contour of the filler spout was altered to conform to this shape of pouch opening, which optimizes the shape and size of the spout to best fit in the pouch and also maximize the flow of fill material. It will be recognized that the invention is functional, even without this additional alteration, which was nevertheless made for the purpose of further optimizing the filling process.
One of ordinary skill in the art will recognize that other accommodations may be made to accommodate the shape of the pouch and opening characteristic of a four-seam pouch used in conjunction with an increased capacity filler wheel.
Details of the invention are now described with the filler wheel apparatus for handling bandoliers of four-seam pouches as further described and in a continuous filling process.
Turning to the drawings, there is shown in FIGS. 4-10 an apparatus 11 for handling an integral bandolier web 1 (FIG. 2) of serially-connected four seam pouches 2, illustrated individually at FIG. 1. It will be appreciated that the pouches are formed preferably from two respective overlying plies of separate suitable pouch material webs 3, 4 having a bottom seam 5 and traverse, typically vertical, side seams 6 and 7. The upper end 8 of the flattened pouch 2 forms an unsealed, closed pouch mouth (the open position shown in phantom in FIG. 1). Each pouch 2 of the bandolier web 1 (FIG. 2) is of similar four-seam configuration. The pouches are connected along their side seams 6, 7 eventually after filling and sealing to be cut apart along cut lines illustrated at 9 in FIGS. 1 and 2.
With more particular reference to FIGS. 4-10 and FIG. 4 in particular, a web 1 is illustrated as being fed toward a transfer or filler wheel 11. The web is a two ply, four seam type bandolier pouch web as described above, and provided by any suitable apparatus producing bottom seam 5. The web 1 passes between a pair of registration rolls 13 driven by a variable speed drive 16.
The registration rolls have been illustrated as being downstream of the web-forming mechanism, but they can perform satisfactorily if located on the upstream side of the mechanism. The web passes by a photoelectric system 17 which reads registration marks on the web and controls the drive for the registration rolls 13 in order to feed the web properly onto the transfer wheel 11 with transverse seals aligned with the lands. The web first passes around a vertical sealer 18 having heated lands. During the excursion around the vertical sealer, the contact of the web with the heated lands creates longitudinally-spaced vertical or transverse seals 19 across the web. As well, bottom seams 5, for example, are also provided by any suitable heated lands. For this purpose the web has an internal film of thermoplastic material capable of being fused by the heated lands in order to create the seals. The seals define individual, although interconnected, pouches in the web. The web plies may also be synthetic films which are sealed together upon application of heat.
One of the registration rolls is driven by a V-belt passing over a spring-loaded pulley. If the belt is driven at a constant speed, increased tension on the belt spreads the pulley apart, thereby permitting the belt to drive a reduced diameter and consequently drive the registration roll at a higher speed.
The web passes by the photoelectric system 17 which reads registration marks at the location of each transverse seal. Another electric eye, on the machine, provides electrical pulses timed to the machine speed. A control system monitors the pulses from the two electric eyes. If the control system determines that the web is beginning to lag with respect to the sealer, means are provided to apply greater tension to the belt which in turn causes the registration roll to speed up, thereby permitting the web to catch up to the sealer. If the web starts to lead the sealer, on the other hand, the control system applies less tension to the belt to correct that situation.
Following the sealing, the web passes around idler rolls 20, 21, one of which may be driven. From the idler rolls 21, the web passes around a feed roll 25. The feed roll may be provided with holes around its circumference connected to a vacuum source in order to securely grip the web 1 as it passes around the feed roll. Preferably, however, the feed roll is simply rubber-coated, the rubber providing a sufficient friction grip on the web to function satisfactorily. The feed roll 25 preferably engages the web above the bottom of the web leaving about one inch of the bottom of the web free from engagement by the feed roll. This lower overhang of the web with respect to the feed roll appears to improve the capability of the bottom of the web ballooning out as it moves onto the transfer wheel.
The feed roll is connected by a slip clutch 26 (FIG. 8) to a drive 27. The drive 27 is a part of the main drive for the pouching apparatus so that the feed roll is driven synchronously with the transfer wheel 11. The slip clutch which reduces the speed of the feed roll from the input speed of the drive 27 by about one to thirty percent maintains a uniform tension on the web as it is fed onto the transfer or filler wheel 11.
The speed of the surface of the feed roll 25 is slightly greater than the speed of the surface defined by the lands 35 of the transfer wheel so as to force the web into the space between the lands on the transfer wheel. A spring steel finger 28 may be mounted adjacent the feed roll and in engagement with the upper portion of the web to prevent the pouches from opening until they pass between the line of centers between the feed roll and transfer wheel. A pressure roll 30 is urged by a compression spring 31 toward the feed roll and securely clamps the web against the feed roll to minimize slippage.
The transfer or filler wheel 11 has a plurality of substantially vertical lands 35 uniformly spaced around the periphery of the wheel. For some applications, the lands may be inclined but here are preferably vertical and parallel to the axis of rotation of filler wheel 11. A tuck finger 36, to be described more fully below, is located midway between each pair of adjacent lands.
It is contemplated that the apparatus be adapted to accommodate webs having different pouch widths, that is, the transverse seals would be on different centers but adapted for filling on the same transfer wheel without changing the spacing of the lands 35. For example, a pouch which is approximately four inches wide can be run on the same transfer wheel with width variations in the range of ¾ inch. This change can be effected by replacing the vertical sealer 18 with one having its sealing lands on the new centers. Additionally, the variable speed drive 16 to the registration roll is altered slightly in order to match the feed of the web to the new spacing of the lands on the sealer. The slip clutch 26 on the feed roll has a sufficient range of slip to continue to apply a uniform tension to the web as it is fed onto the transfer wheel even though the different rate of feeding of the web causes the feed roll to rotate at a different rpm. If the range of the slip clutch is not sufficient to accommodate the changed speed of the feed roll, a feed roll of a different diameter can be used.
The structure of the transfer wheel 11 which is associated with a filling head 40 is best illustrated in FIG. 5. The filling mechanism 40 is diagrammatically illustrated and may be of the type disclosed, for example, in U.S. Pat. No. 3,563,001, incorporated herein by reference. The function of the filling mechanism is to deliver a charge of particulate material to each of the spouts 41 which are uniformly spaced around the perimeter of the transfer wheel and are located above the space between each pair of adjacent lands 35.
The spouts 41 are mounted on a plate 42 which is rotatably mounted by bearings 43 on an inclined shaft 44. As the plate 42 rotates with respect to the inclined shaft, the filler spouts 41 will rise above the lands 35 during the time that the web is being fed onto the transfer wheel. In another portion of the excursion around the circumference of the apparatus, the inclined shaft 44 causes the plate 42 to lower the filler spouts into the space between the lands and into the opened pouches. While in the open pouches, the filler mechanism 40 causes a measured charge of material to be introduced into each pouch through the filler spouts.
The filler wheel 11, mounted below the filler mechanism, is supported on a fixed plate 49 on which a rotatable plate 50, forming a part of the wheel 11, is mounted. The wheel 11 is keyed to a shaft 51 which passes through a sleeve 52 connected by bolts 53 to the plate 50. The sleeve 52 has notches 54 circumferentially spaced around sleeve 56 in its upper end. Each notch 54 receives a roller 55 mounted on the lower end of a sleeve 56 which surrounds the shaft 44. The rollers 55 provide the driving connection between the sleeve 52 and the filler mechanism as the filler mechanism rotates around the inclined shaft 44.
Means, preferably vacuum, are provided for holding the web 1 on the lands 35. Each land 35 is fixed to the perimeter of the plate 50. Each land has a vertical bore 60 which is plugged by a screw 61 at its upper end, the vertical bore being connected to a horizontal bore 62. Projecting outwardly from the bore 60 are four radial bores 63 which provide a vacuum grip on the transverse seals of the web. Vacuum is applied to the lands through a radial bore 64 in the plate 50, the radial bore being connected to a vacuum source 65 which is threaded into an annular block 66 secured to the fixed plate 49. The block 66 has a channel 67 extending around approximately 270° of the circumference of the block 66. The channel begins at about the point that the feed roll 25 drives the web onto the lands (3 o'clock position on FIG. 1A) and extends counterclockwise around to approximately the 6 o'clock position on FIG. 1A where the pouches leave the transfer wheel. Vacuum through the lands 35 is sufficient to retain the four seam pouches thereon for opening and filling without the need for clips or any other pouch holding structures.
A sealing or wear ring 68 is fixed to the rotatable plate 50 and bears on the annular block 66. The sealing plate has a port 69 connected to each bore 64 of each land and forms the communication between the channel and the bore 64.
The face of each land is covered with a soft, resilient strip 70 such as vinyl which has four channels 71 in its face, the channels communicating with the radial ports 63.
The lands may be removed and replaced with lands having a different radial dimension in order to adapt the apparatus to pouches having substantially different widths from those illustrated.
A plurality of tuck fingers 36 are mounted around the perimeter of the plate 50 intermediate adjacent lands 35. Each tuck finger is pivoted at 74 to a bracket 75 mounted on the edge of the plate 50. The pivot axis 74 is located below the axis of the tuck finger about one-half the distance between the point where the finger first engages bottom seam 5 of a pouch and the final upper position of the finger. The tuck finger has a depending arm 76 carrying a roller 77 at its lower end. The roller 77 rides on a circumferential cam 78 fixed to the fixed plate 49 by bolts 79. While the profile of the cam is not illustrated, it should be understood that it has a relatively steep slope extending from about the 3 o'clock position as viewed in FIG. 4 counterclockwise for about 10° so as to cause the tuck finger 36 to swing upwardly and fully up into the bottom of a pouch in about 15° after the pouch has engaged the transfer wheel. Instead of providing a roller follower to connect the tuck fingers to the cam, the connection can be made simply by locating the cam under the fingers and configurating the upper surface of the cam to cause the fingers to raise and lower. The profile of the cam should be such as to maintain the tuck finger in a raised position at least through the filling of each pouch. Filling occurs during approximately the excursion between the 1 o'clock and 10 o'clock positions of the pouch as viewed in FIG. 4. Thereafter, the cam is profiled to permit the tuck fingers to disengage from the bottom of the pouch.
By pivoting the tuck finger below the axis of the finger, the point on the finger which engages the pouch seam 5 initially will slide radially outwardly on the pouch as the finger swings up, and midway in the upward movement of the fingers the point of engagement will move radially inwardly, thereby minimizing the stress on the bottom of the pouch.
In the figures, the tuck finger 36 is shown as a simple cylindrical finger which is about ½ inch in diameter. For some applications, it may be desirable to increase the lateral dimension of the finger by mounting a curved plate or other shaped component on the end of the finger for engagement with the bottom of the pouch. It has been found that for large pouches of approximately 4 inches width, a curved plate having a radius of approximately 2½ inches, tends to eliminate undesirable wrinkling of the pouch when the pouch is engaged by the tuck finger.
Thus, FIGS. 8-10 show a prior art spring clamping clip 82 (FIG. 9) mounted on an L-shaped arm 83 which is pivoted at 84 to a land. The lower end of the arm has a roller 85 which rides against a vertical cam 86 extending around the circumference of the fixed plate 49.
The prior art spring clip 82 was required by the prior art as necessary to handle pouches with a bottom seal. While FIGS. 8-10 are provided herein as showing a necessary prior art construction, such a clip previously described as necessary in the prior art, is specifically omitted in connection with this present invention, applicant having discovered the clip is not necessary for high capacity filling of tucked, four-seam pouches, contrary to the prior art teachings.
The clip was, according to the prior art, necessary for pouches whose structure is such that it is hard to form the tuck in the bottom as, for example, in the pouches made of very stiff material and particularly when the pouches have a seal across the bottom. The cam for the clamping fingers therefore was configurated to thrust the clip against the pouch which has been fed onto the transfer wheel as soon as it contacted a land. The clip remained in place at least until the tuck finger has reached its maximum elevation into the bottom of the pouch which, as indicated above, is after about 15° of travel away from the feed roll 25. Such a clip forms no part of the present invention, the four seam pouches supported on lands 35 alone.
In order to open the pouches, two nozzles are provided to direct blasts of air downwardly into the unsealed top of the pouch. The first nozzle 88 is located just a degree or so counterclockwise from the feed roll 25. The second nozzle 89 is located about the distance between the lands counterclockwise from the first nozzle. The positions of the nozzles are preferably adjustable in order to obtain the best results for different speeds and/or different types of pouches.
The first nozzle has an opening of about ⅛ inch, sufficient to begin the opening of the pouch. The second nozzle has a larger opening, for example, ¼ inch diameter, to provide sufficient air to fill the pouch during the brief time that the pouch passes underneath the nozzle. Improved results are obtained if the airstream from the second nozzle can be flattened out as by using an oblong hole (directed along the width of the pouch) in the nozzle or, alternatively, to direct the flow of air across a plate before it reaches the pouch.
The combination of the manner in which the feed roll frictionally drives the web 1 onto the transfer wheel, coupled with the two air jets for a first opening and then a pouch filling with air, provides assurance that even the hard-to-open pouches are opened satisfactorily.
Downstream of the wheel 11 is a sealer of any suitable type, such as shown in U.S. Pat. No. 4,232,504. The sealer has a curved plate over which the web of now filled pouches passes. In passing the web over the curved plate, the upper portion of the pouches (which are open) is stretched out in order to bring the two lips of the pouch together. The upper portion of the pouches is fed past a heated sealer bar to effect the sealing of the pouches. Optionally, a vibrator may be attached to the plate in order to effect a settling of the particular material in the pouches, thereby providing greater head room at the top of the pouches to facilitate the sealing.
In the operation of the invention, two web plies are passed around the sealer 18 where transverse seals 19 and bottom seal 5 are formed. A representative pouch width at that stage is illustrated at FIG. 2. The two ply web 1 is then passed around the idler rolls and around feed roll 25 where it is driven by the higher surface speed of the feed roll into the spaces between the lands 35 of the filler wheel.
The pouch width, when a pouch is shoved between the lands, is reduced as illustrated in FIG. 3. This reduction in width is accompanied by the opening of the pouch toward a circular or even diagonal cross-section.
In the first 10° of travel of the web around the transfer wheel 11, several things happen. First, a first jet of air from nozzle 88 begins the opening of the pouch just as it leaves the feed roll. Then the second larger jet of air fills the pouch, and opens it completely.
In the meantime, the tuck fingers are cammed upwardly into the bottom seal 5 of the pouches 2 in order to form the tuck and facilitate opening of the pouch mouth for receipt of a filler spout 41.
Vacuum is applied to the lands 35, which vacuum remains applied until the land reaches approximately the 6 o'clock position as viewed in FIG. 4. Thereafter, a blast of air is applied to free the web from the lands. The vacuum is usually sufficient to hold the web on the lands even without the assistance of the clamping clips.
As soon as the pouches are open, and at about the 2 o'clock position as viewed in FIG. 4, the filling spout 41 begins to enter the pouch. The orientation of the shaft 44 around which the plate 42 and filling spout 41 pass is such that the maximum outer or upper position of the spout is at about the 5 o'clock position as viewed in FIG. 4 and the point of maximum insertion into the pouch is at about the 11 o'clock position.
The rotation of the transfer wheel 11 carries the web counterclockwise as viewed in FIG. 4. At about 1 o'clock position, the filling process begins and is concluded at about the 10 o'clock position. During this period, a metered charge of particulate material flows by gravity into the pouches. Optionally, a spring strip 93 may be employed simply to rub against the pouches as they are being filled in order to assist in shaking the product down into the bottom of the pouches. Also, the tuck fingers could be vibrated at this point (during and after the filling sequence) to help settle the product.
The pouches continue to be carried counterclockwise by the transfer wheel 11 and at about the 8 o'clock position the filler spout 41 leaves the pouch. The web is withdrawn from the transfer wheel at about the 6 o'clock position and immediately passes into the sealer mechanism. There, the mouths of the pouches are sealed and the web of pouches passes through a cutting mechanism of the type illustrated in U.S. Pat. No. 3,597,898.
It will be appreciated that the invention thus contemplates an increased capacity filler with vertical, parallel vacuum lands handling four seam pouches which are supported exclusively on and by the lands during tucking and filling; thus permitting the high speed filling of four seam pouches with bottom tucking but without additional pouch supporting or confining structures such as the required clips of the prior art.
The exemplary embodiment disclosed herein, in conjunction with the accompanying documents and figures, is used by way of illustration and is not intended to limit the invention. Other embodiments and variations will be understood by one skilled in the art. The scope of the invention is limited only by the language of the claims and equivalents thereof.

Claims

1. A method of high-speed pouch filling, comprising:

receiving a web comprising a plurality of connected pouches, each pouch defined by side seams oriented on parallel vacuum lands of a wheel and a bottom seam connecting two plies of material to form the walls of the pouch, each pouch further including an upper mouth defined by the top edges of both plies of the material;

holding one of the plurality of pouches along the two side seams of that pouch on said lands, such that the side seams are disposed approximately parallel to each other;

engaging the bottom seam of the one pouch to deform the pouch; and

while holding the side seams parallel and engaging the bottom seam, filling the pouch without engaging the pouch except with said vacuum lands.

2. The method of claim 1, further comprising:

exerting an upward force against the bottom seam of the pouch with said engaging step and causing the opening of the upper mouth of the pouch.

3. The method of claim 2, wherein exerting an upward force against the bottom seam comprises contact between the bottom seam and a moveable tucker insufficient to pull the side seams way from said lands.

4. The method of claim 1, further comprising:

blowing air to cause the upper mouth of the pouch to open.

5. The method of claim 1, wherein the pouch is exclusively held with at least two of a plurality of parallel vacuum lands.

6. The method of claim 5, wherein the plurality of vacuum lands are equally spaced along a filler wheel, the adjacent distance between the vacuum lands less than the width of each pouch such that the spacing of the vacuum lands allows each pouch to open.

7. The method of claim 1, wherein the web comprising a plurality of pouches is filled at a line speed rate in excess of about 5000 inches per minute.

8. An apparatus for high-speed pouch filling, comprising:

a filler wheel having a vertical axis of rotation;

a web comprising a plurality of pouches, each pouch defined by sealed side seams and a bottom sealed seam connecting two plies of material to form the walls of the pouch, each pouch further including an upper open mouth defined by the top edges of both plies of the material;

a plurality of vacuum lands circumferentially spaced below the filler wheel and disposed approximately parallel to the vertical axis of rotation, the lands configured to contact the two side seams of each pouch in the web and for holding each pouch with its side seams approximately parallel to each other; and further comprising a plurality of tuckers each disposed between adjacent lands, each tucker operable to move upward to exert a force against the bottom seam of a pouch, held exclusively by and between the adjacent lands, in order to open the pouch.

9. Apparatus for high speed four seam pouch filling wherein such pouches include two side seams and a bottom seam, said apparatus comprising:

a filler wheel having a vertical axis of rotation;