Patent Publication Number: US-6990792-B2

Title: Carton bottom folding assembly

Description:
BACKGROUND OF THE INVENTION 
   The present invention pertains to a folding device for carton bottoms. More particularly, the present invention pertains to an apparatus for in-folding, for sealing, over-folded carton bottoms. 
   A common form of container for milk, juice and the like is the gable top carton. In this regard, packaging technology has made enormous strides vis-à-vis these gable top cartons, as well as other types of packages. Present technology permits the packaging of perishable food items for non-refrigerated shelf lives that can be as much as 90 days. Such packages provide the ability to bring these food items into parts of the world that have limited transportation, distribution and storage infrastructure. 
   To this end, efforts have been directed to increasing the ability to maintain high levels of cleanliness in forming, filling and sealing these containers to provide the highest quality product and to provide the greatest product shelf life. And, in conjunction with this, the demands on packaging machines have become greater, in particular, relative to operating speeds. One packaging machine in which cartons or packages are formed, filled and sealed in a sterile environment by a single machine an operate at machine speeds that exceed 10,000 packages per hour. 
   In order to maintain the integrity of the package after it is filled and sealed, advanced technologies have been applied to the carton materials, as well as the processing operations. Many such packaging materials are formed from paperboard or fiberboard-based materials formed in a composite structure. Typically, one or more layers, such as polymeric coatings, foil coatings and the like, are applied to the paperboard or fiberboard substrate to reduce or eliminate the gas and liquid permeability of the substrate material. 
   In the form, fill and seal process, it has been observed that the contact of machine parts with the carton material tends to result in the generation of dust. This is particularly so when machine parts contact container material surfaces at relatively high rates of speed (e.g., when machine parts continuously contact container material surfaces relatively soon after the heating process, especially at the bottom forming and sealing process, in that the packaging material surface is easily scratched when the polymer surface is soft). For example, when machine parts (moving at a relative speed that is greater than the speed of the moving container) contact the container. One particular area in which this is observed is the bottom panel folding assembly. 
   Known bottom panel folding assemblies include a pair of spaced apart rotating hubs having multiple outwardly extending fingers. As the carton passes between the hubs, the fingers contact the flaps and fold over the flaps. Although this assembly works quite well to fold the flaps and to provide a well folded and sealed arrangement, it tends to generate a considerable amount of dust. 
   Accordingly, there exists a need for a carton bottom folding device for folding over-folded carton bottoms, which device can be used with known form, fill and seal machines. Desirably, such a folding device can accommodate carton folding operations at the operating speeds of known filling machines. Most desirably, the folding device carries out the folding operation while reducing the amount of dust generated. 
   BRIEF SUMMARY OF THE INVENTION 
   A bottom folding assembly for a packaging machine is configured to infold the bottom side panels, leading panel and trailing panel of a carton for forming a sealed carton bottom. The folding assembly reduces the contact of rotating elements with the carton material to reduce the generation of dust. 
   A packaging machine in which the bottom folding assembly is used includes a carton magazine for storing a plurality of cartons in a flat folded form, and a carton erection station for receiving the cartons and opening the cartons to a tubular form. A rotating turret is positioned for receiving the erected cartons. The turret rotates to define a turret plane. 
   A plurality of carton mandrels are mounted to the turret for rotation with the turret. Each mandrel is configured to receive the carton in the tubular form and to carry the carton with the carton positioned such that a bottom of the carton is positioned at a free end of the mandrel. The machine includes a carton bottom heater located along a rotational path of the turret and a carton bottom sealer located along the rotational path of the turret. 
   The bottom folding assembly is positioned between the heater and the sealer. The folding assembly includes a rotating drive shaft mounted transverse to the turret plane and spaced from a periphery of the turret path. A pair of opposing rotating members are disposed on either side of the rotational path of the turret and are operably mounted to the drive shaft. Each of the rotating members is configured to rotate in a plane that is transverse to the turret plane. 
   A tucking assembly is disposed between the opposing rotating members. The tucking assembly is mounted to the drive shaft for rotating in a plane transverse to the plane of the rotating members and parallel to the turret plane. When a carton is positioned on the mandrel and passes the folding assembly, the opposing rotating members contact the bottom side wall flaps, urging the bottom side wall flaps inwardly, and the tucking assembly contacts the bottom trailing flap, urging the bottom trailing flap inwardly, over the bottom side wall flaps. 
   In a present folding assembly, the opposing rotating members are operably connected to the drive shaft by a transmission for changing a direction of rotational movement. The transmission can include a plurality of gears, such as bevel gears for changing the direction of rotation about 90 degrees. 
   The tucking assembly can includes a mount extending from the drive shaft and a blade disposed at an end of the mount. A preferred embodiment of the tucking assembly includes a roller at an end of the blade to reduce resistance of movement of the blade along the trailing flap. 
   A tab tucker can extend from the mount between the shaft and the blade. The tab tucker is used for tucking the sixth flap or tab that is included in certain types of carton blanks. A form, fill and seal packaging machine having the bottom folding assembly is also disclosed. 
   These and other features and advantages of the present invention will be apparent from the following detailed description, in conjunction with the appended claims. 

   
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     The benefits and advantages of the present invention will become more readily apparent to those of ordinary skill in the relevant art after reviewing the following detailed description and accompanying drawings, wherein: 
       FIG. 1  is a perspective illustration of a form, fill and seal packaging machine having a carton bottom folding assembly embodying the principles of the present invention; 
       FIG. 2A  is a partial plan view of an exemplary carton blank used in conjunction with the form, fill and seal packaging machine; 
       FIG. 2B  is a partial bottom view of a carton bottom shown for reference; 
       FIG. 3  is a partial perspective view of the interior of the packaging machine showing, in part, the folding assembly disposed between the carton bottom panel heaters and the bottom panel sealing station; 
       FIG. 4  is a perspective view of the folding assembly; 
       FIG. 5  is a side view of the folding assembly; 
       FIG. 6  is another perspective view of the folding assembly that shows the drive mechanism for the folding assembly; 
       FIG. 7  is a side view of the folding assembly and drive mechanism; 
       FIG. 8  is illustrates a carton passing through the folding assembly with the fingers in-folding the side panels; and 
       FIG. 9  is an illustration of the carton following that depicted in  FIG. 8 , showing the carton with the tucking blade positioned on the trailing panel, as the carton passes to the guide plate. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   While the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described a presently preferred embodiment with the understanding that the present disclosure is to be considered an exemplification of the invention and is not intended to limit the invention to the specific embodiment illustrated. 
   It should be further understood that the title of this section of this specification, namely, “Detailed Description Of The Invention”, relates to a requirement of the United States Patent Office, and does not imply, nor should be inferred to limit the subject matter disclosed herein. 
   Referring now to the figures, and in particular to  FIG. 1 , there is shown a form, fill and seal packaging machine  10  that includes a bottom folding assembly  12  in accordance with the principles of the present invention. One example of a packaging machine  10  (without the present bottom folding assembly) is disclosed in U.S. Pat. No. 6,012,267 to Katsumata which patent is incorporated herein by reference. 
   The packaging machine  10  includes a carton magazine  14  for storing flat, folded carton blanks B, a carton erection station  16  and a bottom forming and sealing station  18 . The bottom folding assembly  12  is formed as part of the bottom forming and sealing station  18 . 
   The machine  10  can further include a sterilization station  20  for sterilizing the cartons C and further includes a filling station  22  at which the cartons C are filled with product. Following the filling station  22 , the carton top panels are pre-folded and subsequently folded and sealed at a top folding and sealing station  24 . The cartons C are then off loaded from the form, fill and seal packaging machine  10 . The packaging machine  10  illustrated includes a conveyor  26  for transporting a series of cartons C to and through each of the stations. 
   At the bottom forming station  18 , the bottom M of the carton C is heated, folded and sealed to produce an open-top carton with side walls and a sealed bottom. The open top carton C is placed on the conveyor  26  for transport at a predetermined rate, and moves in an indexed manner toward the right as viewed from the perspective of the machine illustrated in  FIG. 1 . The cartons C are typically disposed equidistantly from one another and advance a predetermined number of carton positions during each periodic advancing step (e.g., indexing) of the conveyor  26 . 
   Between each advancing step of the conveyor  26 , the cartons C generally remain stationary for processing for a predetermined period of time. This predetermined period of time generally corresponds to the slowest process on the line in the fabrication of the carton C. The slowest process is generally the sealing of the top of the carton C after the carton C is filled with a desired product. A carton C will await the predetermined period of time, and then proceed, in the indexed manner, on to the next station. 
   Referring to  FIG. 2 , there is illustrated generally, the lower portion of a carton blank B that is configured for forming an overfolded bottom. The blank B has a plurality of bottom panels  102 , a plurality of side panels  104 , a sealing panel  106  and a sixth panel or tab  108 . Each of the bottom panels  102  is partitioned from a corresponding side panel  104  by a horizontal score line  110 . Each of the bottom panels  102  is partitioned from adjacent bottom panels by vertical score lines  112  (with vertical score line  114  partitioning bottom panel  102  from the sealing panel  106 ). One exemplary carton C is that disclosed in U.S. Pat. No. 6,328,204, to Stacy-Ryan, which patent is commonly assigned with the present application and is incorporated herein by reference. 
   The bottom panels  102  each have diagonal score lines  116  respectively, for folding the bottom panels  102  inward during the bottom forming process. The sixth panel or tab  108  is partitioned from bottom panel  102  by a horizontal score line  118 . Although an overfolded carton blank B is illustrated, those skilled in the art will recognized that other carton blanks, including traditional TETRA REX® carton blanks, may be used with the present invention without departing from the scope and spirit of the present invention. It will also be recognized that the carton blank B can be of the type having an interior aluminum barrier layer. 
   As shown in  FIG. 3 , the bottom forming station  18  includes generally, a turret  28  with mandrels  30  projecting therefrom. The turret  28  rotates about a fixed axis A 28  to rotate each of the mandrels  30  to sub-processing stations disposed about the turret  28 . 
   The magazine  14  stores a plurality of carton blanks B and feeds erected carton blanks individually to a mandrel  30  at an infeed station  32 . The erected carton blanks have the bottom panels  102  projecting outwardly from the mandrel  30  in order to heat, fold and seal the bottom panels  102  together to form the carton sealed bottom wall M. 
   Following carton C erection and placement on the mandrel  30 , the carton C is indexed to the next sub-processing station, the heating station  34 , in which the bottom panels  102  are heated for sealing. The bottom panels  102  are heated to a temperature that is about equal to the melting point of a thermoplastic coating that is formed on the carton blank B. A typical coating is a low density polyethylene. 
   The next station is the sealing station  36 , in which the bottom panels  102  are sealed to one another. Mounted between the heating station and the sealing station is the novel folding assembly  12  of the present invention. The folding assembly  12 , in conjunction with the sealer  36  facilitates forming a tight seal on each carton C that is processed at the bottom forming station  18 . The final sub-processing station on the bottom forming station  18  is the discharge station, in which the carton C, with its newly sealed bottom wall M, is discharged to the conveyor  26  for further processing on the packaging machine  10 . 
   The bottom folding assembly  12  is configured to minimize the relative movement of the portions of the folding assembly  12  that contact the carton C. As seen in  FIGS. 3 and 4 , the folding assembly  12  includes a main drive shaft  40  that is oriented transverse to the plane P 28  defined by the rotational movement of the carton turret  28 . The drive shaft  40  rotates to drive the folding assembly  12 . 
   A pair of opposing, inwardly rotating finger assemblies  42  are operably mounted to and driven by, the drive shaft  40 . The finger assemblies  42  each include a transmission  44  that reorients the rotational movement of the shaft  40 . A spindle  46  is mounted to the transmission  44 , transverse to the shaft  40 . The spindle  46  is driven by the shaft  40  through the transmission  44 . In a present embodiment the transmission  44  includes a pair of crown or bevel gears  48 ,  50 . As will be appreciated by those skilled in the art, one gear  48  is mounted to the drive shaft  40  and meshes with the second gear  50  which is mounted to the spindle  46 . A finger  52  extends radially from the spindle  46  to cross the path of the carton C as the carton C passes the folding assembly  12 . As set forth above, each folding assembly  12  includes a pair of such fingers  52 , with the fingers  52  opposing each other to contact the opposing sides of the passing carton C. In a present dual process packaging machine  10  (that forms, fills and seals two cartons in a side-by-side manner), two such folding assemblies  12   a ,  12   b  are mounted to a common drive shaft  40 . 
   The folding assembly  12  further includes a tucking assembly  54  that is mounted to the shaft  40  between the finger assemblies  42 . The tucking assembly  54  is mounted to the shaft  40  so as to rotate directly from and along with the shaft  40 . The tucking assembly  54  includes a mount or extender  56  having an outer tucking blade  58  mounted thereto. The blade  58  has a leading end  60  that includes a roller or bearing  62  and a trailing end  64 . The blade  58  is mounted to the folding assembly  12  so that it rotates along with the drive shaft  40  with the blade  58  rotating about the shaft  40 . 
   The tucking assembly  54  can include a tab tucker  66 . The tab tucker  66  is formed similar to the blade  58  and extends from the mount  56  between the shaft  40  and the outer tucking blade  58 . The tab tucker  66  extends forwardly, that is in same direction as the blade  58 , and serves as an inner tucking blade when used to form the bottom M of a carton C having a “sixth” panel or tab  108 , such as that disclosed in the above-noted patent to Stacy-Ryan. As seen in  FIGS. 6 and 7 , the folding assembly drive shaft  40  is driven by a drive mechanism  68  that can include an indexing shaft  70  that is operably coordinated with the overall form, fill and seal machine  10 . 
   In operation, prior to folding, a carton C that is loaded onto the mandrel  30  is indexed (i.e., rotated) to the bottom panel heaters  34 . The heaters  34  heat the bottom panels  102  to soften the polymeric coating to prepare the panels  102  for folding and sealing. 
   The carton C is then indexed (rotated) toward the bottom sealing station  36 , passing the bottom folding assembly  12 . It should be noted that in the present machine  10 , the carton C does not stop at the folding assembly  12 , rather, it passes the folding assembly  12  as it moves toward (and stops at) the reciprocating bottom sealing plate  72 . 
   As the carton C approaches the bottom folding assembly  12 , the bottom panels  102  are essentially extending outwardly as an extension of the carton side wall panels  104 . The bottom panels  102  include a leading panel  102   a , as the first panel approaching the folding assembly  12 , a trailing panel  102   b  (from which the tab  108 , if present, extends) as the last panel approaching the assembly and a pair of side panels  102   c  that include triangular, in-folded panels  120 . 
   As the carton C approaches the folding assembly  12 , the blade  58  is out of the way, e.g., above, the carton C path, and the fingers  52  are out of the way, e.g., outside of, the carton C path, in that they have not yet rotated into the carton C path. As the carton approaches, the drive shaft  40  is timed so that the ends  74  of the fingers  52  contact an upper portion of the triangular panels  120 , just at the point at which the length of the fingers  52  permit touching the carton C. That is, in that the fingers  52  are rotating and the carton C is moving between the rotating fingers  52 , the fingers  52  contact the carton C when the triangular bottom panels  120  are just at the point at which the fingers  52  can touch or reach the carton C. 
   At this point, the blade  58  is rotating downward, toward the trailing panel  102   b . As the blade  58  rotates down, because the panels  102  are still, to a great extent, extending “upwardly” from the side panels  104 , the tab tucker  66  engages and “holds” the sixth panel or tab  108 , essentially bending it backward. In this manner, rather than permitting the tab  108  to be positioned within the carton C adjacent an interior portion of the leading panel  102   a , the tab  108  is “pulled” back so that it lies between the trailing panel  102   b  and the infolded side panels  102   c . This configuration is intended to prevent any liquid within the package from contacting an uncoated or raw edge of the packaging material. Again, such a carton C configuration is disclosed in the aforementioned patent to Stacy-Ryan. 
   With the blade  58  continuing its downward movement and with the fingers  52  continuing inward rotation, the panels  102  are urged inward and downward to form the bottom wall M, essentially as seen in  FIG. 9 . As such, the tab or sixth panel  108  has “pulled” away from the tab tucker  66  and the blade  58  contacts the trailing panel  102   b . This urges the panel  102   b  to fold inward. As the carton C continues toward the bottom sealing plate  72 , it first engages a guide plate  76  that retains the panels  102  in the folded position as the carton C moves to the sealing plate  72 . The guide plate  76  maintains the panels  102  infolded prior to sealing. 
   As set forth above, the cartons C are conveyed through the machine  10  at a predetermined velocity and the shaft  40  is timed to rotate so that the fingers  52  contact the carton bottom side panels  102   c  as the carton C approaches the “inlet” to the bottom folder  12 . The shaft  40  rotational velocity is such that the tangential velocity of the tucking blade  58  is about equal to the linear velocity of the carton C. As such, the tucking blade  58  “contacts” the carton C as the carton C enters the folder  12  and, as the carton C continues to move through the folder  12 , the tucking blade  58  remains in contact with the panel  102   b , but does not substantially move (longitudinally) along the panel  102   b . Thus, the tucking blade  58  essentially contacts a spot on the panel  102   b  and remains in contact with that spot as the carton C moves through the folding assembly  12 . It has been found that such an arrangement reduces the amount of moving or sliding contact between the machine  10  parts and the carton C material. This, in turn, reduces the amount of dust that may otherwise be generated by contact of “moving” parts with the carton C material. 
   All patents referred to herein, are hereby incorporated herein by reference, whether or not specifically done so within the text of this disclosure. 
   In the present disclosure, the words “a” or “an” are to be taken to include both the singular and the plural. Conversely, any reference to plural items shall, where appropriate, include the singular. 
   From the foregoing it will be observed that numerous modifications and variations can be effectuated without departing from the true spirit and scope of the novel concepts of the present invention. It is to be understood that no limitation with respect to the specific embodiments illustrated is intended or should be inferred. The disclosure is intended to cover by the appended claims all such modifications as fall within the scope of the claims.