Abstract:
A folding aid with registers is aligned with notches in a specially designed carton blank to facilitate the efficient manual construction of cartons with gusseted corners.

Description:
FIELD OF THE INVENTION 
     This invention relates to an apparatus, carton blank and method for manually manipulating such a carton blank using the apparatus to form a gusseted, rectangular box that may be filled with products, locked, closed, and stacked. 
     BACKGROUND OF THE INVENTION 
     The food service industry consumes both an enormous quantity and great diversity of packaging, and particularly cartons or boxes, for food products. In commercial food production, cartons are formed at the packaging manufacturer on specialized automated equipment; are delivered to food processing facilities; and are filled and closed, usually in a highly automated fashion with additional specialized and automated closing equipment. However, in retail food service establishments such as fast food restaurants and specialty food shops such as confectioners, bakeries, groceries, and caterers, it is rarely practical from either an economic or logistical standpoint to employ specialized automated equipment to fill and close food cartons. Instead at such retail food service establishments, the food packaging process is manually performed. Several of the most common types of packaging are described below: 
     Formed, Prefolded and Glued Cartons: 
     Many styles of cartons may be formed then glued at the packaging converter on specialized equipment. Also, some types of cartons may be molded (shaped) from suitable materials, even though many suitable molding materials are foams or plastics that may not be environmentally friendly. To minimize space requirements at the user&#39;s location, the cartons may be designed to nest within one another when stacked. When a need arises for one of these preformed cartons, one is selected, filled with one or more food items, and manually closed, typically with some type of latching apparatus constructed in the lid or in one or more of the side walls. Even though preformed cartons may be nested and packed to reduce space requirements, such cartons are both more voluminous than the flat carton style blank packs (or bundles) and the nested styles require shipping in corrugated boxes. Conversely flat carton style blanks can be shipped with only plastic wrap packaging, and have only minimal amounts of empty space within the wrapped package. 
     Folded Carton Blanks/Glued and Unglued: 
     Alternatively, folded carton blank styles of paperboard (or other similar fibrous materials) may be obtained from a packaging converter and processed by automated folding and sealing apparatuses at the food processing facility to create cartons ready for loading and locking. Many cartons of this same style are also employed in the retail food service industry, and such cartons are preferably supplied in configurations so that the retail establishment does not require excessive space to store these types of cartons. This box style is particularly common with boxes (that due to size or structural and performance needs), cannot be easily nested (vertically stacked inside one another). However, the manual preparation of cartons at retail food service outlets diverts valuable employee time from the preparation and service of food. Some of these box styles can be prefolded and stored in a collapsed state and then opened and erected into their useful carton shape, usually with some further interlocking to maintain the shape, and thereby minimize the time required to create a useful carton from a flat blank (see  FIGS. 1 a    &amp;  1   b ). However, most designs for collapsible cartons have foldable and multi-part bottom panels that are not suitable to hold many food products. Such multi-part bottom cartons are characteristic of “perimeter type” blanks. 
     Conventionally, such a perimeter type box or carton is manufactured from a sheet of relevant material in a number of stages. First, the sheet is cut and creased to form the carton blank. The cuts and creases mark out the relevant portions of the carton panels that will form the carton&#39;s front, rear and side walls, its top and bottom surfaces, and any necessary flaps, tongues and slots, and so provide the blank with the shape that will define the resulting carton. The cuts and creases are also located to enable the basically flat sheet to be folded in the way required to construct the desired three dimensional carton. The perimeter construction usually requires one flap-part of the blank to be permanently affixed, by glue or staples for instance, to another part (usually one of the areas of the blank defining a wall panel of the carton). The next stage is to effect this affixation and the blank is conveniently designed so that this can be done with only a single fold of the blank and in such a way that a flat, easily stored, collapsed version of the carton results. Finally, for use, the folded and affixed blank is opened up and then further folded along the provided creases so as to move the wall and top and bottom portions into their required carton-defining positions. A typical example of a perimeter type blank for an exemplary box is shown as  FIG. 1 a   , while  FIG. 1 b    shows the box erected from that blank. It can be seen that the perimeter type construction leads to openings in the bottom of the carton between the multiple panels that form the bottom surface, and this structure does not lend itself to creation of an economical leak-resistant carton. 
     Flat Carton Blanks/Unglued: 
     Pizza boxes are a common example of this box style used in a retail food service packaging application. In contrast to the perimeter type blank, a typical pizza box is of a “base type” construction with a central panel to form the bottom of the carton and having wall and top panel extensions disposed around the base. However, this design is both time consuming to assemble and lacks leak resistant corners. A blank suitable to construct a base type pizza box is depicted in  FIG. 2 a    and the carton constructed from that blank is shown in  FIG. 2 b   . However, the base type blanks can be unnecessarily complicated. It is difficult to provide a leak resistant carton of base type construction that can be quickly assembled on an as needed basis. 
     Accordingly, there is a need for improved carton designs and methods of assembly suitable for use in retail food service settings. The present invention provides, in various embodiments, one or more of a carton blank, a carton folding aid, and a method of carton forming adapted to allow retail food service business to create leak resistant cartons from blanks in an efficient and economical fashion. 
    
    
     
       BRIEF DESCRIPTION OF THE INVENTION 
       Features of the present invention will become more readily apparent from the following description taken in conjunction with the accompanying drawings in which: 
         FIG. 1 a    is a prior art perimeter type carton blank. 
         FIG. 1 b    is a carton assembled from the prior art blank of  FIG. 1   a.    
         FIG. 2 a    is a prior art base type carton blank. 
         FIG. 2 b    is a carton assembled from the prior art blank of  FIG. 2   a.    
         FIG. 3  is an exemplary blank suitable for use in certain aspects of the invention. 
         FIG. 4 a    is a perspective view of an exemplary folding aid for use in practicing aspects of the carton forming steps of the invention. 
         FIG. 4 b    is a top plan view of the folding aid of  FIG. 4   a.    
         FIG. 4 c    is a sectional view of a folding guide of the folding aid of  FIG. 4   a.    
         FIG. 5 a    is a perspective view of the exemplary blank of  FIG. 3 a    positioned on the folding aid of  FIG. 4   a.    
         FIG. 5 b    is a first sequential illustration of the carton blank and folding aid of  FIG. 5 a    as the blank is pushed into the folded aid and the carton panels begin to be folded. 
         FIG. 5 c    is a second sequential illustration of the carton blank and folding aid of  FIG. 5 a    with the carton panels substantially folded. 
         FIG. 5 d    is a perspective view of a carton formed by the carton blank of  FIG. 3  after folding as illustrated in  FIGS. 5 a   - 5   c.    
         FIG. 6  is a perspective view of outward and folded gusset constructions in isolation. 
         FIG. 7  is a perspective view of stacks of three different carton constructions. 
         FIG. 8  is a top view of an exemplary carton after opening. 
         FIG. 9  is a contrasting perspective view of two-inch standard clamshell containers that are shipped nested in a corrugated box versus flat carton blanks of the type suitable for the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The prior art carton blank  10  of  FIG. 1 a    is of interest for the flaps  11   a - 11   d  that form the base of the erected carton shown in  FIG. 1 b   . Prior to folding into a collapsed state, the perimeter of the carton is attached by the use of adhesive on tab  13  to connect to wall  12   a . In the blank&#39;s collapsed state, not shown separately, the base forming flaps  11   a - 11   d  are folded up between the walls  12   a - 12   d  of the carton, and as the erection process takes place, the flaps  11   a - 11   d  drop down into place through what becomes the volume enclosed by the carton  10 ′. Thus, the carton  10 ′ of  FIG. 1 b    is erected from the blank  10  which, in its collapsed state, has its base flaps  11   a - 11   d  folded upwards to lie against its inner wall surfaces  12   a - 12   d , and then upon erection, these flaps  11   a - 11   d  are encouraged to drop down into place, passing through the volume that is the inside of the carton  10 ′. The notches  14   b ,  14   d  on flaps  11   b ,  11   d  respectively, interlock so that the carton formed has some stability. Due to the multi-part base formed of flaps  11   a ,  11   b ,  11   c , and  11   d , it is not appropriate to put food items in the carton  10 ′ that might exude liquid, since the liquid could leak out between the base flaps  11   a - 11   d.    
     Turning then to the prior art base-type carton blank  20  of  FIG. 2 a   , the base  21  of the carton is a unitary panel surrounded by wall panels  22   a - 22   d . At the ends of side wall panels  22   a ,  22   c  are rear folding tabs  25   a ,  25   c  and front folding tabs  26   a ,  26   c . Connected along the top edge of rear wall panel  22   b  is top panel  24  and its side panels  23   a ,  23   c ,  23   d . When constructed, the folding panels  29   a ,  29   b  of front wall  22   d  are folded inward so that panel  29   a  is adjacent and interior to front wall  22   d , while panel  29   b  is frictionally engaged along the forward portion of the base  21 . Tabs  26   a ,  26   c  folded inward and are inserted into the channel formed between front wall  22   d  and panel  29   a  while rear tabs  25   a ,  26   c  are folded inward of the rear wall  22   b . The top  24  with its side panels can be folded downward so the side panels  23   a ,  23   c ,  23   d  are aligned inward of the side walls  22   a ,  22   c ,  22   d . While the base type blank  20  forms a carton  20 ′ with a solid base  21 , the corner portions with front and rear tabs  25   a ,  25   c ,  26   a ,  26   c  are not in the form of gussets and fluid leakage may occur through those corner portions. 
     A different base type blank  30  that may be utilized in some aspects of the invention is illustrated in  FIG. 3  and when utilized with folding aid  50  (shown in  FIGS. 4 a -4 c   ) provides for the rapid construction of a carton  30 ′ (shown in  FIG. 5 d   ) with a solid base  31  and outfold gussets at the corners that provide structural strength and resist leakage. The principal elements of blank  30  in  FIG. 3  include the previously mentioned base  31 , surrounded by fold lines  41   a - 41   d  that separate base  31  from the wall panels  32   a - 32   d . The top of rear wall panel  32   a  has fold line  42  by which it is attached to top panel  36  which has a folding top flex lip  37  and latching tab  38  that flex or pivot along the fold line  47 . Front wall panel  32   c  has a front lip flap  34  with latching opening  35 , the flap  34  folding along line  44  where it connects to front wall  32   a . Of particular interest are the outfold gusset forming elements and alignment notches  61  at the corners of the wall panels  32   a - 32   d . Specifically, with regard to left wall panel  32   d , there are inward fold score lines  48   a ,  48   c  and outward fold score lines  45   a ,  45   c . These fold score lines allow side panel front edge  33   c  and rear edge  33   a  to be folded and faced against front panel landing area  43   c  and rear panel landing area  43   a  to form outfold gusset corners. The outward fold score lines  45   a ,  45   c  are oriented at about a 135° angle with respect to both the adjacent side wall fold line  41   d ,  41   b  and the rear wall fold line  41   a . At the edges of the left wall side panel  32   d , the inward fold score lines  48   a ,  48   c  are oriented at about a 100-105° angle with respect to the side wall fold line  41   d  and about a 165-170° angle with respect to the adjacent rear wall fold line  41   a  and front wall panel fold line  41   c.    
     A similar outfold gusset structure is accomplished on the opposite side with right wall panel  32   b  and inward fold score lines  48   a ,  48   c  and outward fold score lines  45   a ,  45   c  allowing rear edge  39   a  and forward edge  39   c  of right wall panel  32   b  to be folded and faced against front and rear panel landing areas  49   c ,  49   a  respectively. Where the side panel front edges  33   c ,  39   c  and rear edges  33   a ,  39   a  are wider than rear wall panel  32   a  and front wall panel  32   c  alignment notches  61  are created. The formation of the outfold corner gussets is further elaborated as the use of carton blank  30  in connection with the folding aid  50  is discussed in connection with  FIGS. 5 a   - 5   d.    
     Turning then to the folding aid  50  illustrated in  FIGS. 4 a -4 c   , the aid  50  comprises a base surface  51  with four registers  52   a ,  52   b ,  52   c  and  52   d  located in the corner areas of the surface. It is possible to implement the invention with only two registers, typically proximate one edge of the surface  51 , however, four registers facilitate the prompt location of a carton blank on the aid  50 . Also on the surface  51  are four folding guides, namely the illustrated right guide  53 , rear guide  54 , left guide  55  and front guide  56 . The four guides define an open rectangular base surface area within which a carton may be seated. Each guide, as shown in the sectional view of  FIG. 4 c   , has a mounting segment  55   a , a vertical segment  55   b  and an introductory segment  55   c . The mounting segments  53   a ,  54   a ,  55   a ,  56   a  may have a variety of configurations, however, the depicted embodiment is designed for ease of bonding or welding the guide to the surface  51 . It would be possible to mold the surface and guides as an integral piece, in which case no mounting segment would be necessary. The vertical segments  53   b ,  54   b ,  55   b ,  56   b  of the guides are preferably not precisely vertical but instead have an outward slant of approximately 5-20 degrees from the vertical. The introductory segments  53   c ,  54   c ,  55   c ,  56   c  are preferably angled outward at approximately 30-60 degrees from the vertical. As described below, the outward slant of the vertical and introductory segments assists in guiding the base of a carton blank toward the surface  51 . In order for the carton blank to be properly positioned, the registers should be located outside the introductory segments of the folding guides. 
       FIG. 5 a    depicts the placement of blank  30  on folding aid  50  with the four registers  52   a - 52   d  disposed in the alignment notches  61  of the blank to locate the blank  30  on the folding aid  50  in proper relationship to the folding guides  53 - 56 . Typically, the distances between the folding guides will be approximately 1/10 th  to 4/10ths of an inch greater than the corresponding width or length of the carton blank base  31 . As illustrated in  FIG. 5 a   , the carton wall panels  32   a - 32   d  are located intermediate the registers  52   a - 52   d . In order to form a carton, downward pressure is placed on the base  31  and this pushed the base  31  toward the surface  51  while the folding guides hold the wall panels  32   a - 32   d  away from the surface. This causes the blank  30  to begin to fold along fold lines  41   a - 41   d  and the side panels  32   a - 32   b  begin to tilt upward from the planar base  31 . In addition, the outward gusset folds of  45   a ,  45   c  each begin to fold outward while the inward gusset folds  48   a ,  48   c  begin to fold inward.  FIG. 5 c    depicts the carton blank  30  when the base  31  has been pushed substantially into contact with surface  51  of folding aid  50 . In this position, the side walls  32   a - 32   d  are erect and the corner gusset surfaces  33   a ,  43   a  and  33   c ,  43   c  on the left, as well as  39   a ,  49   a  and  39   c ,  49   c  on the right, are facing and contacting or nearly in contact with each other. The base and folded erect side walls create and define an interior carton space or volume for the placement of food products (and possibly ancillary items such as utensils). In order to secure the gusset surfaces against one another, the front lip flap  34  is folded rearward and the top  36  is folded downward with latch panel  38  tilted by pivoting flex lip  37  so that latch panel  38  can be inserted into front lip opening  35 , resulting in the closed container configuration  30 ′ shown in  FIG. 5 d    with four outfold gussets. Numerous alternate latch configurations are possible, including placing openings on one or more of the side wall panels  32   b - 32   d  and having one or more lip flaps extending downward from the top  36  with a latch panel to engage a corresponding side wall panel opening. 
     The result is that by simply pushing the base  31  of carton blank  30  downward into contact with the folding aid surface  51  and folding the front lip flap  34  and top  36  with flex lip  37  and latch panel  38  the entire carton is constructed. Preferably the carton is filled while still sitting in the folding aid  50  and closed and latched and removed so the folding aid  50  may receive another carton blank  30 . The latched carton  30 ′ has an outfold gusset at each corner which provides a greater strength to weight ratio than is typically achieved in either ungusseted or folded gusset constructions. The gusset structure is shown in isolation in  FIG. 6  where the outfold gusset panel  33   c  is folded outward from sidewall  32   d  and flush against the gusset landing area  43   c  of the front wall  32   c.    
     The most similar carton designs are prefolded cartons with outfold gussets that are folded alongside the side walls of the carton and glued in place at extra expense, as shown with gusset  63  glued to sidewall  65  in  FIG. 6 . The unglued outfold gussets of the described embodiment, however, when combined with vertical side panels  32   a ,  32   b ,  32   c , and  32   d  provide greater strength than folded or glued gussets of clamshell cartons and also allow more ready access to the interior of the carton when it is unlatched. As previously mentioned, prefolded and glued cartons are also more voluminous. 
     The carton strength and stackability is illustrated in  FIG. 7  with exemplary cartons formed according to aspects of the invention  30 ′ are stacked adjacent to cartons  60 ′ with folded and glued outfold gussets, and clamshell cartons  70 ′. It can be seen that the clamshell cartons  70 ′ are less amenable to stacking and the sidewall and gusset structure of those clamshell cartons  70 ′ provides less rigidity. Because it is necessary to be able to nest the empty clamshell cartons  70 ′ during shipment (as shown in  FIG. 9 ) and prior to use, the sidewalls of clamshell cartons must tilt slightly outward from the base, and do not provide vertical rigidity. 
     When the carton  30 ′ is unlatched and opened the front wall panel  32   c  tends to release forward slightly as the carton blank  30  tends to slightly return toward its original flat shape. This slight flattening of the wall panels provides ready access to contents of the carton, as shown in  FIG. 8 . The efficiency with which strong, leak resistant cartons can be created utilizing the blanks, folding aid and method of the present invention is an improvement over prior art designs that do not include some preassembly of the carton. In addition, carton blanks according to the invention and folding aid dimensions may be adjusted to create a variety of carton sizes according to the needs of any particular food service establishment. 
     The economies in shipping and storage may be better appreciated with reference to  FIG. 9  where clamshell cartons  70 ′ are shown formed, glued, and stacked in nested arrangement in corrugated carton  76 . In contrast the carton blanks  30  suitable for use in the present invention can be shipped completely flat, wrapped only in a flexible covering such as plastic wrap, and even palletized, with a space savings of over 30%, 40%, 50%, 60% and even 75% for smaller quantities (one to twelve dozen) relative to nested cartons. Plastic wrap  77  for clamshell cartons  70 ′ is also greater than the wrap  75  for flat carton blanks  30 . The result is that the carton blanks  30  require less transit space for shipping and less storage space after delivery. In addition to these savings, by avoiding the manufacturing steps of folding and gluing the blank, the carton blanks can be delivered to the retail food service establishment at lower cost. 
     All publications, patents and patent documents are incorporated by reference herein as though individually incorporated by reference. Although preferred embodiments of the present invention have been disclosed in detail herein, it will be understood that various substitutions and modifications may be made to the disclosed embodiment described herein without departing from the scope and spirit of the present invention as recited in the appended claims.