Tray erector

Abstract
The present invention provides an apparatus that can erect a tray from a generally flat, rectangular blank. The tray erector incorporates an inventory section, a transfer section, a construction section and an exit section. The inventory section has a hopper with flanges and tab stops, which hopper stores an inventory of stacked, flat blanks that will eventually become the trays. In the transfer section, a blank is transferred from the inventory section to the construction section of the present erector. The construction section includes a setup assembly and a locking assembly. The setup assembly folds the pre-cut and scored end and side panels of the tray blank up into approximately perpendicular planes in relation to the plane of the bottom panel of the blank. The end and side panels are folded up from the plane of the bottom panel of the blank in preparation for the locking of the corner webs. While the end and side panels are folded, the corner webs begin to extend out from the tray due to the actions of folding the end and side panels. The locking assembly of the construction section completes the remaining tray folding and locking steps, and an erected tray is produced. This includes folding the web corners against the end panels, and locking the web corners to form the finished tray. The erected tray then drops from the construction section to the exit section, where the tray is guided onto a conveying device, preferably a moving delivery conveyor belt.
Description




BACKGROUND OF THE INVENTION




1. Field of the Invention




The present invention relates generally to a paperboard carton erector capable of preparing a folded carton from a flat blank, and relates more specifically to an automated erector that folds a flat, die-cut blank of laminated paperboard or corrugated paperboard into a tray, which tray can be used for baking, shipping and storing food and other products. The present invention erects shallow, open-top trays having leakproof corner constructions. The design and folding of the blank eliminates the need for gluing, taping and the like to lock the tray's walls in an upright configuration.




2. Description of Related Art




Conventional foldable cartons are well known and are used worldwide in a variety of applications. For example, the packaging industry utilizes a vast number of cartons in which numerous products are packaged for subsequent shipment. Similarly, a variety of automated carton erectors exist for folding cartons. Foldable cardboard carton erector devices are known for setting up folded carton or box blanks, closing their bottom flaps, and sealing the bottom flaps so the carton can be loaded. Many of the cartons folded by a box erector are commonly referred to as slotted boxes or cases known as a RSC (regular slotted case). These cartons are shipped to a packaging company as stacks of flat collapsed blanks for ease of handling and shipment. After arriving at the packaging company, the blanks are placed into a box erecting apparatus, usually located immediately adjacent a packaging machine. Box erectors automatically remove collapsed boxes individually from a magazine and by various mechanisms, move a box to an unfolded open position, immediately after which the erector automatically moves a pair of minor and major closure flaps on the bottom of the box into a closed position so the box, upon reaching the end of the erector, is in a top open position so that any articles to be contained therein can be inserted manually or automatically into the open top of the erected box. Yet these box devices are not entirely suitable, particularly because they are relatively complicated in construction, and require a large amount of floor space.




These types of disadvantages similarly plague conventional tray erecting devices. Automated construction of foldable trays has been limited primarily to the high-speed production of like trays of the same size. For example, six-pack trays with or without a shrink wrap assist are well known and are produced in high speed and great volume. These types of trays are designed to retain the lower portion of the containers by providing a bottom and four secured sides. While these sides may be secured by a binding means like staples, adhesive is conventionally preferred since the tray is thus much more rigid and the possibility of injury to one's hand during emptying is greatly reduced.




The conventional binding method uses a thermally sealable coating on the carton blank. The places that are to be fastened together are coated and heated by hot air, and thereafter these places are subjected to pressure by clamping jaws, clamping rollers or the like. During erection of these types of trays, the sides or flaps are laid one above the other and fastened by the heat and pressure.




Trays also can be erected by hand, versus automatically, although this method requires both more manpower and more floor space than needed with an automated tray erector.




Typical tray construction begins by manipulating a scored flat sheet or blank. While there may or may not be cutouts in the tray blank providing grip assists for lifting the tray, tray blanks generally have cutout portions that provide tabs that are folded to secure end and side walls. Conventionally, the erected tray has the side and end walls of substantially the same height.




In the conventional erection of a rectangular tray-type carton from a flat blank, it is known to fold the end and side wall panels of the carton approximately perpendicular from the bottom panel of the carton, and then to secure those panels in their desired formation by means of folded gussets formed from gusset panels which join the end and side wall panels integrally together.




Foldable paperboard and corrugated paperboard trays have been developed for a variety of uses, and have been found to provide an economical means for storing and transporting a variety of products. For example, disposable concession trays, such as those disclosed by U.S. Pat. No. 4,705,173 to Forbes, Jr. and U.S. Pat. No. 4,757,937 to Maio, et al., have been found to provide inexpensive and disposable containers for transporting food and drink. These foldable paperboard containers are typically fabricated from a die-cut paperboard blank, and can be stored in a flat configuration, in order to minimize space requirements during shipping and prior to their use by the consumer. The paperboard blanks are typically configured in a manner that permits quick and easy assembly into their erected configurations when placed into use. Unless otherwise indicated, the term “paperboard” herein will also include corrugated paperboard.




The nature of paperboard and corrugated paperboard cartons, however, limit their use to post-preparation storage and handling of most food products. For example, typical paperboard and corrugated paperboard are generally inadequate for use during the baking or cooking of food items, as the materials from which they are constructed will burn or char at elevated temperatures. A shallow wall baking tray is disclosed by U.S. Pate. No. 4,632,302 to Manizza.




Moreover, the structural configuration of many known foldable paperboard or corrugated paperboard containers prevents the containers from being utilized in applications where fluid contents are introduced into the container. In particular, the corner construction of many known foldable paperboard or corrugated paperboard containers includes slits or openings in the blank to facilitate the formation of corners or locking panels when the blank is folded into its assembled configuration. Thus, if fluid contents are introduced into the assembled container, the contents will leak from the container.




For example, the Manizza '302 patent shows a folded panel baking tray wherein the tray's corners comprise an open slot between upright sidewalls, resulting from the tray's assembly from a blank having a generally rectangular corner cutout. When the blank of the Manizza reference is foldably assembled to form a shallow tray, adjacent edges of the sidewall panels at this corner cutout form a slotted corner which is incapable of retaining fluid contents. Moreover, the C-shaped or caddie cuts required along the base panel of the Manizza tray present further openings from which fluid contents can leak. It has also been recognized that containers such as that disclosed by the Manizza reference suffer the further disadvantage that gluing of certain panels is necessary to assemble the container. Such gluing results in additional time and expense to assemble the container, and is preferably avoided.




U.S. Pat. No. 4,844,331 to Oldfather discloses another variety of foldably assembled container. This container includes a corner assembly formed by a slit in the die blank that may permit any fluid content to leak. In addition, a slot is cut into the main panel of this assembly near its corner to receive a locking tab for retaining the structure in its assembled configuration. This slot, owing to its location adjacent the floor of the assembled container presents a further point of potential leakage of fluid contents.




U.S. Pat. No. 4,832,257 to Wood shows a paperboard tray having folded corners requiring no cut lines or openings. However, in order to retain this tray in its assembled configuration, it is necessary to adhesively secure the corner assemblies in their upright configuration. The necessity of gluing disadvantageously requires additional time and expense in the assembly of this tray. Also, because the corner assemblies must be glued to retain the tray in its upright configuration, the tray cannot readily be knocked down into a generally flat configuration for more easy access to the contents of the tray, without substantially damaging the tray. Thus, the tray disclosed by this reference is not suitable for applications in which it is desired to periodically disassemble and reassemble the tray. Moreover, the corner assemblies of this variety of tray are typically glued in the assembled configuration at their point of manufacture. Therefore, the blanks cannot be shipped to their point of use in a flat, unfolded configuration.




Therefore, it can be seen that a need yet exists for a compact and efficient automated erector for constructing a paperboard or corrugated paperboard tray container, which tray can be used for baking, shipping and storing food and other products. The tray should be foldably constructed from a flat, die-cut blank, and should enable fluid contents to be contained therein without the use of glue that can liquefy upon heating in an oven.




BRIEF SUMMARY OF THE INVENTION




Briefly described, in its preferred form, the present invention provides an apparatus that can erect a tray from a generally flat, rectangular blank. The typical blank manipulated by the present erector generally comprises: a bottom panel bounded by first and second end score lines and first and second side score lines; first and second end panels connected to the opposite ends of the bottom panel at the first and second end score lines; first and second side panels connected to the opposite sides of the bottom panel at the first and second side score lines; and, corner webs or gussets adjacent each corner of the bottom panel between adjacent end and side panels.




The blank further preferably comprises a heat-resistant laminate of paperboard or corrugated paperboard and an inner and/or outer liner of heat-resistant, leakproof material. The preferred liner material is a polyester film bonded by polyethylene to the paperboard material.




The erected tray has leak-proof corner assemblies wherein a tab portion of each corner is folded against the tray's exterior and engaged within a retaining slit in the end panel of the tray when a flap portion of the end panel is folded over the corner tab. The slit retains the corner tab and maintains the tray in its assembled configuration. This “roll-over lock,” being formed to the tray's exterior, does not interfere with the use of the tray's interior space, and provides a convenient “handle” by which to grasp the assembled tray. In the tray's assembled configuration, the retaining slit is adjacent to the top edge of the tray's end wall, where the retaining slit does not present a lower opening from which fluid contents can leak from the tray.




The tray erector of the present invention comprises an inventory section, a transfer section, a construction section and an exit section. The inventory section preferably includes a hopper having flanges and tab stops, which hopper stores an inventory of stacked, flat blanks that will eventually become the trays. Each blank has both an outside and inside face. Upon manipulation, the outside face of the blank forms the outside surface of the tray. The inside face of the blank, which preferably is laminated, forms the interior surfaces of the constructed tray. The inventory section of the erector is preferably the uppermost portion of the erector, as the various sections lie vertically.




In the transfer section of the present erector, a blank is transferred from the inventory section to the construction section of the present erector. The transfer section includes a transfer mechanism and a grasping mechanism both to grasp a bottom blank from the inventory section, and then transfer the bottom blank to a release position situated over the construction section. The blank is released from the grasping mechanism at the release position and slides down to, and rests atop, a stop member in the construction section. Thus, the bottom blank is transferred from a stacked position in the inventory section into a tray-construction position in the construction section. Generally, the blank travels down through the present invention from the release position through to the exit section by means of gravity feed.




The construction section includes a setup assembly and a locking assembly. The setup assembly folds the pre-cut and scored end and side panels of the tray blank up into approximately perpendicular planes in relation to the plane of the bottom panel of the blank. The end and side panels are folded up from the plane of the bottom panel of the blank in preparation for the locking of the corner webs. While the end and side panels are being folded, the corner webs begin to extend out from the tray due to the actions of folding the end and side panels.




The locking assembly of the construction section completes the remaining tray folding and locking steps, and an erected tray is produced. This includes folding the web corners against the end panels, and locking the web corners to form the finished tray.




The erected tray then drops from the construction section to the exit section, where the tray is guided onto a conveying device, preferably a moving delivery conveyor belt.




The present device is automatic and only requires an attendant to replenish the tray hopper and insure that jams do not occur or are freed in short order. Additionally, a trained attendant performs the adjusting of size for product changes.




Accordingly, an object of the invention is to provide a tray erecting apparatus for foldably constructing a unitary blank into an open top container, wherein the blank preferably comprises: a generally rectangular bottom panel; first and second side panels connected to opposite sides of the bottom panel; first and second end panels connected to opposite ends of the bottom panel; and corner webs or gussets continuously connecting adjacent side panels and end panels.




Another object of the invention is to provide a tray erector that can be utilized to erect different size trays without undergoing extensive retooling.




Yet another object of the invention is to provide a tray erector which erects trays taken from an inventory of stacked blanks in a smooth and reliable manner.




It is a further object of the present invention to provide a tray erector that can erect a tray-shaped paperboard or corrugated board laminated container, which container prevents the leakage of fluid contents such as cake batter.




These and other objects, features and advantages of the present invention will become more apparent upon reading the following specification in conjunction with the accompanying drawing figures.











BRIEF DESCRIPTION OF THE FIGURES





FIG. 1

shows a foldable laminated corrugated paperboard container constructed by the present invention, according to a preferred form, in its assembled configuration.





FIG. 2

shows the foldable laminated corrugated paperboard container of

FIG. 1

, in a partially assembled configuration for illustrative purposes.





FIG. 3

shows a laminated corrugated paperboard blank of the container of FIG.


1


.





FIG. 4

illustrates a preferred corner web or gusset of the blank of FIG.


3


.





FIG. 5

shows a cross-sectional detail of a laminated corrugated paperboard of the blank of FIG.


3


.





FIG. 6

is a perspective view of a tray erector according to a preferred form of the present invention.





FIG. 7

is a side view of a tray erector according to the present invention.





FIG. 8

illustrates the inventory and transfer sections of the present tray erector according to a preferred embodiment.





FIG. 9

illustrates the inventory and transfer sections of

FIG. 8

, wherein the blank has been transferred from the inventory section by the transfer mechanism





FIG. 10

illustrates the setup assembly of the construction section of the present tray erector according to a preferred embodiment.





FIG. 11

illustrates the folding of the sides of the blank by the setup assembly of FIG.


10


.





FIG. 12

illustrates the folding of the ends of the blank by the setup assembly of FIG.


10


.





FIG. 13



a


illustrates the locking of the sides and ends of the blank by the locking assembly of the present erector according to a preferred embodiment.





FIG. 13



b


illustrates the flippers and actuators of the locking assembly of

FIG. 13



a.







FIG. 14

illustrates the folding of the flap panel over the locking tabs of the corner web by the locking bars.





FIG. 15

illustrates the ejector plate moving the erected tray out from the tray's construction location and into the exit section of the present erector.





FIG. 16

illustrates the exit section of the present tray erector according to a preferred embodiment.





FIG. 17

illustrates the conveyor mechanism of the exit section of FIG.


16


.











DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT




Briefly described, in its preferred form, the present invention provides an apparatus for erecting a generally rectangular tray from a blank. The description of preferred tray erectors of the present invention follows the description of preferred blanks manipulated by the erectors. In this manner, the erector descriptions of the present invention will be clearer as the erector descriptions can relate to the manipulation of specific elements of the blank and tray.




The Blank




Referring now in detail to the drawing figures, wherein like reference numerals represent like parts throughout the several views,

FIG. 1

shows an erected open top container produced by the present invention, which container generally comprises an open-top tray or tray


10


having a bottom


12


, first and second side walls


14


,


16


and first and second end walls


18


,


20


. Thus defined, the baking tray


10


comprises a generally rectangular, open-top box.




The baking tray


10


is constructed by folding a one-piece blank


30


, which is shown in preferred form by FIG.


3


. The blank


30


is die cut and scored, according to known techniques, from a flat sheet of heat-resistant laminated paperboard or corrugated paperboard having a laminated linerboard, which material will be described in greater detail below.




The blank


30


generally comprises a bottom panel


32


having a top face and a bottom face, which, when the blank


30


is foldably assembled to form the baking tray


10


, forms the bottom


12


of the baking tray


10


. The bottom panel


32


is generally rectangular, and is bounded by first and second end score lines


34


,


36


, and first and second side score lines


38


,


40


.




The blank


30


further comprises first and second end panels


50


,


52


, connected to the opposite ends of bottom panel


32


at first and second end score lines


34


,


36


, respectively. When the blank


30


is foldably assembled to form the baking tray


10


, the first and second end panels


50


,


52


form the first and second end walls


18


,


20


, respectively, of the baking sheet


10


. The first and second end panels


50


,


52


are generally identical mirror images of one another and, therefore, for purposes of brevity, only the first end panel


50


will be described in detail. It will be understood that the second end panel


52


is of similar construction to that described. First end panel


50


preferably comprises an end wall panel


54


and a flap panel


56


, connected to one another by means of a hinged fold joint


58


, which will be described in greater detail below. End wall panel


54


is generally rectangular, having a width equal to that of the bottom panel


32


, and a height he generally corresponding to the desired wall height h


e


of the side walls


70


,


72


of the baking tray


10


.




The hinged fold joint


58


comprises perforated sections


60


,


62


at each end of the abutting line between the end wall panel


54


and the flap panel


56


, and further comprises a retaining slit


64


extending between the perforated sections


60


,


62


along the central portion of the line of connection between the end wall panel


54


and the flap panel


56


. The perforated sections


60


,


62


each comprise a generally parallel pair of perforations or score lines


63




a


,


63




b


, the perforations or score lines being spaced apart from one another a distance s, at least approximately twice the thickness of the laminated paperboard or corrugated paperboard comprising the blank


30


, and preferably approximately four times the thickness of the laminated paperboard forming the blank


30


for ease of erecting the tray


10


. Each of the parallel perforations or score lines


63




a


,


63




b


is of a length d. To facilitate the folding of the tray and the locking of the locks, a knifecut


66


can be provided between the interior ends of the perforations


63




a


,


63




b.






The perforated sections


60


,


62


can also have knifecuts


67


centered along perforations


63




a


and


63




b


to ensure the proper locking and holding position of the locked baking tray


10


.




It will be evident that if the blank


30


is comprised simply of fold lines, and had no knifecut portions, any tray formed of blank


30


could retain liquid only to the height of the shortest panel. For example, if blank


30


did not include perforated sections


60


,


62


, upon assembly blank


30


would be leakproof up to a height h


e


or h


s


, depending on which of these heights was shortest as measured from the respective score lines


34


,


40


.




The retaining slit


64


extends along the central portion of the abutting line between the end wall panel


54


and the flap panel


56


, from the approximate midpoint of the knifecut


66


at the interior end of each perforated section


60


,


62


. Although the embodiment depicted by

FIG. 3

shows the retaining slit


64


extending along the entire central portion of the abutting line between the end wall panel


54


and the flap panel


56


between the perforated sections


60


,


62


, one or more additional perforated sections, of similar construction to those described above can be provided along the central portion of the line of connection between the end wall panel


54


and the flap panel


56


, in order to prevent excessive spread of the retaining slit


64


when the blank


30


is assembled to form the baking tray


10


.




The blank


30


further comprises a first side panel


70


and a second side panel


72


which, when the blank


30


is foldably constructed into the baking tray


10


, forms its first side wall


14


and second side wall


16


, respectively. The first and second side panels


70


,


72


connect to the bottom panel


32


at first and second side score lines


38


,


40


, respectively. The first and second side panels


70


,


72


are generally rectangular, having a length equal to that of the bottom panel


32


, and a height h


s


corresponding to the desired wall height of the side walls


14


,


16


and approximately equal to the height he of the end wall panels


54


.




The blank


30


preferably further comprises corner webs or gussets


80


, adjacent each corner of the bottom panel


32


between an adjacent end wall panel and a side panel. The four corner webs


80


are generally identical and, therefore, for purposes of brevity, only a single representative corner web


80


A will be described in detail. As shown in

FIG. 4

, the corner web


80


A connects to side panel


70


at a score line


82


, and connects to end wall panel


54


at a score line


84


. A diagonal score line


86


extends centrally along the corner web


80


A, between the adjoining corner of the bottom panel


32


and an outer corner


88


of the corner web


80


A as shown in FIG.


3


. Alternatively, the outer corner may be a truncated corner


88


A, as shown in FIG.


4


. In a preferred embodiment, the score line


86


extends a distance through the juncture of score lines


34


,


38


and into bottom panel


32


, as shown by extension


86




a


of score line


86


. Additionally, for ease in erecting the tray


10


, score line


86


can have a knifecut portion


87


provided near the outer corner


88


A of corner web


80


A.




Generally rectangular cutouts


90


,


92


are provided along each exterior edge of the corner web


80


A, to form top locks


94


,


96


, respectively. Each cutout


90


,


92


is of a length I


c


, which is preferably incrementally greater than the length d of the respective perforated sections


60


,


62


of the end panel


50


to provide clearance for the top locks


94


,


96


to engage the retaining slit


64


during assembly. The cutouts


90


,


92


are preferably of a height h


c


from bottom cutout lines or bottom edges


90




b


,


92




b


to top edges


90




t


,


92




t


. Top locks


94


,


96


can be separated by knifecut portion


87


and score line


86


, or just by score line


86


. Thus described, it can be seen that the corner webs


80


are generally symmetric about the diagonal score line


86


.




Bottom edge


92




b


is preferably incrementally nearer score line


82


than perforation


63




a


is to score line


34


, so that the flap panel


56


can be folded about the perforations


63




a


,


63




b


during assembly, without interference from the corner web


80


A. Thus as described before, the height at which the present tray


10


is leakproof is that height from score lines


34


,


38


to bottom edges


92




b


,


90




b


, respectively. Since, upon construction of the tray


10


, that height is only incrementally less than the height of the end walls


18


,


20


, the present tray


10


provides leakproof assembly to nearly the height of the end walls


18


,


20


which height is easy to visualize by the user.




In one preferred embodiment of corner web


80


A, perforations


63




a


and


63




b


are approximately ⅜ inches apart, perforation


63




a


is approximately ⅛ inch above bottom edge


92




b


, and retaining slit


64


is approximately {fraction (5/16)} inches above bottom edge


92




b


. Further, while bottom edge


90




b


can be perpendicular to side edge


90




s


and parallel to top edge


90




t


, in preferred form side edge


90




s


is angled approximately 98 degrees from bottom edge


90




b


, and substantially perpendicular to top edge


90




t


. It will be understood that the above ranges of measurements are preferred ranges.




The present tray


10


provides an easily disassembled roll-over lock so that products in the tray


10


can be removed without deformation of the product by moving the sides and ends of the tray


10


back down into the flat blank


30


configuration. The roll-over lock requires only a purposely directed, gentle urging to unlock the sides and ends of the tray


10


. To remove a baked product from the tray


10


, for example a cake, one need simply fold the side and end wall panels down. Thus, one does not need to place a spatula or the like at side, end or corner locations to “scoop out” a portion of the baked food product.




The blank


30


preferably comprises a heat-resistant laminated paperboard or corrugated paperboard. Preferably corrugated paperboard known by the name E-flute is used, however, the blank


30


can be fabricated from any of a variety of foldable paperboard, cardboard, or other materials. In order to provide a leakproof and heat-resistant container, the material comprising the blank


30


is preferably a laminated composite including a layer of plastic film bonded to the paperboard, cardboard, or other material of construction. The laminated composite material comprising the blank


30


is shown, according to one preferred form, by FIG.


5


. As depicted, a corrugated paperboard stock


100


is provided with a layer of plastic film


102


on at least one of its faces. In most preferred form, the plastic film layer


102


will be provided on the interior of the assembled baking sheet


10


to prevent liquid content from being absorbed by, or from leaking through the baking sheet


10


. Alternatively, the plastic film layer


102


can be provided on the exterior of the baking sheet


10


, or on both the interior and exterior thereof




In its preferred form, the tray


10


comprises a composite material of corrugated paperboard having a layer of bi-oriented polyester film bonded thereto through the use of a polyethylene bonding agent


104


. U.S. Pat. No. 5,772,819 to Olvey, the teaching of which is incorporated herein by reference, discloses such a composite material, and a method of making said material.




The composite laminate material preferably comprising the blank


30


of the tray


10


is fabricated by passing a web of paperboard or kraft paper and a web of plastic film such as a bi-oriented polyester through the nip of a pair of nip rolls, extruding a molten plastic impregnating and bonding agent, such as polyethylene, at an elevated temperature of approximately 600° F. into the nip between the paper and plastic film webs, such that part of the molten plastic agent impregnates partially into and becomes part of the paper web and a portion of the plastic agent extends outwardly of the paper web surface and forms a new solidified surface on which the plastic film is supported and to which the plastic film is firmly bonded.




The preceding paragraphs describe the various features of the preferable blank


30


forming tray


10


as constructed by the present erector described hereinafter.




The Erector




As shown in

FIGS. 6 and 7

, the automated tray erector


200


of the present invention that forms the tray


10


from the blank


30


preferably comprises an inventory section


300


, a transfer section


400


, a construction section


500


and an exit section


600


. The present tray erector


200


preferably has a frame


210


suitably configured to present the erector


200


as a single unit. The frame


210


provides a chassis upon which each of the various elements of the present erector


200


may be secured and allows an operator sufficient space between components to navigate inside and around the erector


200


should there be any need to repair the erector


200


. Further, the present tray erector


200


has appropriately located guards (not shown) to protect an operator or observer from accidental entanglement with the operating and moving components of the erector


200


. Preferably, the guards are transparent and are fixed upon the chassis


210


, and are easily removable for inspection of erector


200


. The erectors


200


of

FIGS. 6 and 7

are movable about a floor space by wheels


212


.




The inventory section


300


preferably comprises a hopper


310


having bent flanges


312


and tab stops


314


, which hopper


310


stores an inventory of stacked, flat, pre-cut tray blanks


30


.




As shown in

FIGS. 6-9

, in the transfer section


400


, a bottom blank


320


of the stacked blanks is transferred from the inventory section


300


to the construction section


500


of erector


200


. Transfer section


400


comprises a transfer mechanism


410


that transfers the bottom tray blank


320


forward against the bent flanges


312


of the hopper


310


. The transfer mechanism


410


includes a grasping mechanism to grasp the blank


320


in order to transfer it. The blank


320


is then released and slides down the bent flanges


312


to, and rests against, a stop member


480


shown in FIG.


7


. Thus, the bottom blank


320


of the inventory of blanks


30


is transferred from the stacked position in the inventory section


300


to a tray-construction position sitting atop stop member


480


in the construction section


500


.




The inventory section


300


of the present invention continually positions a bottom tray blank


320


in a pick-up position, wherein the inside face of the blank


30


(preferably laminated) is facing the grasping mechanism


410


. Each time the transfer mechanism


410


of transfer section


400


transfers the bottom blank


320


to the construction section


500


, a blank


30


previously stacked above the bottom blank


320


is automatically lowered and becomes the new bottom blank


320


.




The construction section


500


receives a rectangular blank


30


as it rests atop stop


480


, and comprises both a setup assembly


510


and a locking assembly


560


. In the setup section


510


, the pre-cut and scored end and side panels


50


,


52


,


70


, and


72


of the tray blank


30


are initially folded up from the parallel plane of the bottom panel


32


of the blank


30


in preparation for the locking assembly section


560


of the construction section


500


. The locking assembly


560


completes the remaining tray folding and locking, and an erected tray


10


is then produced.




The erected tray


10


then falls from the construction section


500


to the exit section


600


, where the tray


10


is guided to an exiting device, preferably a moving delivery conveyor belt


610


. The exit section


600


can incorporate a sensing mechanism to detect each tray


10


as it proceeds through the exit section


600


, which sensing mechanism is capable of stopping the operation of the present tray erector


200


should an error in tray exiting be detected, thus preventing possible damage to the trays


10


or the erector


200


. The exit section can further comprise a stabilizing device


630


that ensures each falling tray


30


consistently lands smoothly onto the exiting device


610


. The stabilizing device can be a set of rubber fingers or the like to keep tray


10


from bouncing off the conveyor belt


610


when dropped from the construction section


500


.




Construction of the Baking Tray




Initially, flat tray blanks


30


are loaded into the hopper


310


, shown stacked in

FIGS. 6 and 8

. The hopper


310


has a tab stop


314


, bottom guide


316


and bent flanges


312


. The tray blanks


30


are disposed so the blanks


30


slope forward within hopper


310


. Generally, the blanks


30


are positioned in hopper


310


so a blank's


30


side wall


70


or


72


lies adjacent to bottom guide


316


, so end wall panels


50


,


52


are perpendicular to bottom guide


316


. As blank


30


is preferably symmetrical, either side wall


70


,


72


may rest upon guide


316


. Further, the inside face of each blank


30


faces the grasping mechanism


410


, and thus eventually each inside face rests against one or more tab stop


314


.




Tab stop


314


extends downward into contact with bottom blank


320


holding back the stack of stacked blanks


30


and is adjustable so as to accommodate the varying widths of different lots of tray blanks


30


. The hopper


310


is easily adjusted to accommodate different length and width sizes of blanks


30


. The inventory section


300


of the present invention also positions a bottom tray blank


320


into a pick-up position, wherein the bottom tray blank is releasably held in place by tab stop


314


until blank


320


is received by the grasping mechanism


410


.




In a preferred embodiment, the hopper


310


is designed to accommodate full size and ¼, ⅓ and ½ size trays, and can hold over


150


blanks stacked one on top of another. Further, such changeover can be completed in less time than presently possible, for example, thirty minutes or less. If the blanks


30


are laminated on one side, it is preferable to have the laminated side (inside face) facing the grasping mechanism


410


.




As shown in

FIG. 7

, the transfer section


400


preferably comprises transfer mechanism


410


including a linked first and second transfer arm


420


,


430


, and a transfer drive (not shown) for rotating the linked transfer arms


420


,


430


(the combination of both first and second transfer arms


420


,


430


will sometimes be referred to singularly as the articulated transfer arm


460


) through a prescribed angle between the pick-up position of bottom blank


320


and the release position over the construction section


500


. In a preferred embodiment, the articulated transfer arm


460


is engaged with the transfer drive at the first transfer arm


420


. The transfer drive rotates the articulated transfer arm


460


first through the prescribed angle, and then back in an opposite direction into the bottom blank


320


pick-up position. Alternatively, the transfer arm


460


may not be articulated, but comprise a single integral component.




Transfer arm


430


has a grasping device to grasp the bottom blank


320


, so transfer arm


430


can move the bottom blank


320


through tab stop


314


to the release position. Preferably, the grasping device is vacuum assembly


450


. The vacuum assembly


450


is carried by the second transfer arm


430


for grasping the inside face of the bottom panel


32


of the bottom blank


320


. The vacuum assembly


450


includes vacuum suction cups


452


for engaging the inside face of the blank


320


in the pick-up position. The vacuum suction cups


452


are in communication with a source of vacuum, for example, venturi pump


454


illustrated in FIG.


8


. The articulated transfer arm


460


releasably grasps the bottom blank


320


via the suction devices


452


at the pick-up position, and swings the blank


320


into a generally vertical orientation at the release position, as the transfer arm


460


rotates between the pick-up and release positions. The articulating arm


460


feeds the bottom tray blank


320


forward against the bent flanges


312


of the hopper


310


, where it is released and slides down the flanges


312


to, and rests atop, stop


480


.




As is shown in

FIGS. 8 and 9

, vacuum assembly


450


preferably has three suction cups


452


configured in such a way so that when the suction cups


452


contact the inside face of bottom blank


320


, the blank is releasably secured to transfer arm


460


so that transfer arm


460


can pull bottom blank


320


with enough force to overcome tab stop


314


so that bottom blank


320


may move between the pick-up position and the release position. The blank


320


is released by cutting off the vacuum to the suction cups


452


.

FIG. 8

illustrates transfer arm


460


ready to engage bottom blank


320


in the pick-up position. In

FIG. 9

, the transfer arm


460


has moved blank


320


forward against flanges


312


and has released the blank


320


at the release position, wherein the bottom blank


320


has slid down flanges


312


and stopped in the construction section


500


.




The construction section


500


constructs the blank


320


(referred now as blank


30


) into a tray


10


. The blank


30


, as described above, can be foldably constructed to form the baking sheet or tray


10


, as will now be described in greater detail.




The construction section


500


includes the setup assembly


510


and the locking assembly


560


. The setup assembly


510


folds the end and side panels


50


,


52


,


70


and


72


upward from the plane of the bottom panel


32


of blank


30


. The setup assembly


510


comprises a ram assembly


520


having a ram


522


and an actuating means


530


for moving the ram


522


approximately normal to the blank


30


. The setup assembly


510


slides between a retracted position and an extended position. The setup assembly


510


preferably further comprises ram tooling plates


542


,


544


, ejector plate


546


, and side folders


552


,


554


.




As the blank


30


is symmetrical about lines of both vertical and horizontal bisection, so too the construction section


500


comprises several components that are symmetrical both above and below, and to the left and right of, lines of bisection both horizontally and vertically, respectively, of bottom panel


32


of a blank


30


. For example, in preferred form, ram tooling plate


542


is identical to ram tooling plate


544


, and side folders


552


and


554


are similarly identical. Such design limits the production costs of the present invention.

FIGS. 10 and 11

show manipulation of blank


30


in the construction section


500


. Description of these and the following figures may detail only one of a set of components. For example, when describing only ram tooling plate


542


and side folder


552


, it will be understood that these descriptions are identical to the description of ram tooling plate


544


and side folder


554


.




Referring back to

FIG. 7

, when blank


30


first comes to rest on stop


480


, setup assembly


510


is in the retracted position, away from contact with blank


30


. In the retracted position, the ram head


523


(shown in

FIG. 10

) is retracted from contact with blank


30


. The ejector plate


546


and locking assembly


560


are located on the other side of blank


30


from the ram


522


, also out of contact with blank


30


.




The ram


522


with ram head


523


and ram tooling plates


542


,


544


is driven by the actuating means


530


to first engage the inner face of the bottom panel


32


of the blank


30


, and then continue to extend and exert pressure on the blank


30


, trapping it against the ram tooling plates


542


,


544


and ejector plate


546


. The ram


522


and tooling plates


542


,


544


overcome the forces maintaining the blank


30


in its single plane configuration, and press the trapped blank


30


against ejector plate


546


between the side folders


552


,


554


, thus folding the tray side panels


70


and


72


approximately 90 degrees about first and second side score lines


38


,


40


upward from the flat plane, as shown in

FIGS. 10 and 11

.




The tooling folders


552


,


554


preferably are curved so they gently urge side panels


70


,


72


to fold about score lines


38


,


40


while the ram head


523


continues to push the blank


30


through the aperture between the two folders


552


,


554


. Upon full extension of ram


522


, the side panels


70


,


72


are preferably perpendicular to the plane of bottom panel


32


of blank


30


, wherein the panel


32


remains sandwiched between ram head


523


and ejector plate


546


.




The side panels


70


,


72


are then momentarily folded a further approximately 90 degrees and onto the inside face of the bottom panel


32


and released to return approximately perpendicular to the bottom panel


32


. The side panels


70


,


72


are further folded by the extension of tooling extenders (tooling extender


556


is shown and extends side folder


552


). While the ram


522


extends blank


30


between the folders


552


,


554


, the folders


552


,


554


remain fixed in a first position. In order to fold the side panels


70


,


72


the further 90 degrees, tooling extender


556


extends the top edge


557


of tooling folder


552


through to a second, extended position. The side folders


552


,


554


preferably are rotationally driven about an axis aligned with score lines


38


,


40


by tooling extenders (tooling extender


556


is shown in FIG.


11


), so that side panels


70


,


72


are folded 180 degrees about score lines


38


,


40


.




As shown in

FIG. 11

, the length of side folder


552


is preferably shorter than the length of side panel


70


so that the side folder


552


does not interfere with or contact web


80


. The side folders


552


,


554


are then returned to their first positions. It has been found that rotating side panels


70


,


72


through 180 degrees leaves side panels


70


,


72


in approximately perpendicular planes to bottom panel


32


upon rotation of side folders


552


,


554


back into their first, retracted positions. Depending on the material construction of blank


30


, the over-rotation of side panels


70


,


72


beyond approximately 90 degrees may need to be less than an additional approximately 90 degrees. It will be understood that the over-rotation may be varied, but should leave the side panels


70


,


72


free-standing approximately perpendicular to bottom panel


32


.




After the side panels


70


,


72


have been folded, the end panels


50


,


52


are then folded approximately perpendicular to bottom panel


32


by end folders


562


,


564


. The end folders


562


,


564


are rotationally driven about an axis aligned with score lines


34


,


36


by end extenders (end extender


563


is shown and extends end folder


562


) from a retracted position to an extended position so that end panels


50


,


52


are folded approximately 90 degrees about score lines


34


,


36


. As shown in

FIG. 12

, the length of end folder


562


is preferably shorter than the length of end panel


50


so that the end folder


562


does not interfere with or contact web


80


.




Upon the folding of the end panels


50


,


52


, the four corner webs


80


are themselves kicked outward (due to scoring of the blank


30


and the completed folding of side panels


70


,


72


), ending up folded 180 degrees onto themselves, and sticking out on all four corners of the tray


10


, as shown in FIG.


12


. At this point in time, the side folders


552


,


554


are in their retracted positions, and the end folders


562


,


564


are in their extended positions. The end folders


562


and


564


contact the outside surfaces of the end panels


50


and


52


of blank


30


, and fold these panels about their respective score lines.




The locking assembly


560


then folds the four folded corner webs


80


by four flippers


566


, mounted on four preferably 180 degree actuators


568


, against the end panels


50


,


52


as shown in

FIGS. 13



a


and


13




b


. Referring specifically to corner web


80


A, the corner web


80


A is folded outwardly and about the diagonal score line


86


, so that the corner web


80


A forms flap


120


extending outwardly from the corner formed at the edge where score fines


82


,


84


meet, as seen best in FIG.


2


. The flap


120


comprises generally triangular elements having top locks


122


extending upwards from their top edges


124


. In reference to the blank of

FIG. 4

, the flap


120


comprises generally triangular elements having top locks


94


,


96


extending upwards from bottom cutout lines or bottom edges


90




b


,


92




b


along side edges


90




s


,


92




s


. As the flap


120


comprises the corner web


80


A folded upon itself at diagonal score line


86


, the flap


120


(and the top locks


122


thereon) have a total thickness of twice the thickness of the laminated paperboard comprising the blank


30


.




Extension


86




a


of score line


86


into the bottom panel


32


ensures that the juncture point of folding at each corner of bottom panel


32


(for example, the intersection of first end score line


34


and first side score line


38


) does not interfere with the folding of corner webs


80


to form flaps


120


.




The flap


120


is next folded outwardly onto the exterior surface of the first end


18


by a flipper


566


, as the flap


120


is shown by FIG.


1


. When the flap


120


is folded against the end


18


, the top edges


124


of the flap


120


are preferably adjacent, or incrementally below, the lower perforations


63




a


of the hinged fold joints


58


, and the top locks


122


lie alongside the perforated sections


60


,


62


and extend upwards a distance above the retaining slit


64


to facilitate locking and unlocking.




Next, the flap panel


56


is then folded downward along the hinged fold joint


58


, towards the exterior of the baking tray


10


, as seen best in

FIG. 1

, by the rotation of locking bars


572


,


574


, shown in

FIG. 14

, whereupon the locks


122


are engaged within the retaining slit


64


. The flipper


566


must keep flap


120


in proximity to end


18


long enough so rotation bar


572


can rotate flap panel


56


and the retaining slit


64


over lock


122


.




The locking bar


572


is rotationally driven about an axis aligning with retaining slit


64


by bar extender


573


from a retracted position to an extended position so that flap panel


56


is folded approximately 180 degrees about retaining slit


64


. Thus, locking bar


572


must move from a position inside the forming tray, through initial contact with flap panel


56


, then rotating flap panel


56


approximately 180 over retaining slit


64


, finally ending up on the outside face of flap panel


56


outside the tray.




Because the locks


122


extend upwards a distance, preferably at least the thickness of the material comprising the blank


30


, above the retaining slit


64


, the locks are retained within the retaining slit


64


, and also secure the flaps


120


against unfolding away from the end walls


18


,


20


of the baking tray, thereby forming a substantially rigid, leakproof corner.




A knifecut portion


87


is preferably provided near the outer corner


80


A of representative corner web


80


A as shown in

FIGS. 2 and 4

to eliminate a wide rolling fold that typically occurs from the end of the knifecut


87


to the juncture of score lines


34


,


38


, if corner web


80


A did not have knifecut


87


. Knifecut


87


and score line


86


form the two top locks


94


,


96


, and allow the locks


94


,


96


to work independently of one another as the flap panel


56


is folded downward along the hinged fold joint


58


. The knifecut portion


87


ensures the proper insertion of the locks


122


up through retaining slit


64


, and the proper holding of the flaps


120


form the tray


10


.




Knifecuts


67


centered along perforations


63




a


and


63




b


ensure the proper rollover of the perforated section


60


over the double thickness of rectangular cutouts


90


,


92


, which also aid in forming the proper locking and holding position for the locked tray


10


.




Moreover, because the spacing s between the perforations


63




a


,


63




b


is at least twice, and preferably four times the thickness of the laminated paperboard comprising the blank


30


, the width of the retaining slit


64


in the assembled configuration of the baking tray


10


provides a positive locking action when the top locks


122


are engaged within the retaining slit


64


, without the necessity of gluing. This positive locking feature results in part from the provision of a retaining slit


64


which, when the container is assembled and the flap panel


56


is folded downwardly adjacent the end wall panel


54


, opens to a width of approximately twice the thickness of the stock comprising the blank


30


when the spacing s between perforations


63




a


,


63




b


is approximately four times the thickness of the stock comprising the blank


30


(owing to the thickness of the end wall panel


54


and flap panel


56


). When the spacing between the perforations


63




a


,


63




b


is less than four times the thickness of the stock comprising the blank


30


, the width of the retaining slit


64


in the container's assembled configuration will, correspondingly, be less than twice the stock's thickness. In this manner, the retaining slit


64


is of approximately the same thickness as, or somewhat less than, the thickness of the locks


122


that are retained therein.




The corners of the baking sheet of the present invention do not present any openings from which fluid contents can leak. The fluid contents remain enclosed within tray


10


up to the height of top edges


124


of flaps


120


.




Upon completion of the locking steps by the locking assembly


560


, each tooling component is returned to its retracted position, and the ejector plate


546


is moved in the opposite direction it was initially pushed by the ram


522


. The finished tray


10


is then ejected from the tooling by the ejector plate


546


, and stripped from plates


542


,


544


as the ram cylinder


522


retracts, shown in FIG.


15


. As the ram


522


retracts, the completed tray


10


slides down the guide plate


582


and onto the moving delivery conveyor belt


610


of the end section


600


shown in

FIGS. 16 and 17

.




The exit section


600


can further comprise a sensor beam assembly (not shown) to detect the tray


10


as it drops onto the conveyor belt


610


, automatically stopping the erector


100


if a tray


10


is not detected by a certain time, preventing possible tooling damage. If a tray


10


is detected each time, the erector


100


continues to run.




The erector


100


can be changed over to form assorted tray sizes by adjusting the above-described components. Further, the erector


100


comprises movement means to power the various components of the erector


100


. The movement means can be a variety of power and translation of power embodiments, for example, vacuum and cam controls. All folding and vacuum preferably is air powered. In one embodiment, the erector utilizes 80 psi with 5 cfm, and start, stop; safety switches, sensors and conveyor belt are electric and operate on 110-120 Volts.




The present tray erector can run at a variety of speeds, and preferably can be set to run a fixed speed of up to 25-28 cycles per minute. Once set for a specific speed, a variable speed range of plus or minus ten percent from the fixed speed may be used. In a preferred form, the weight of the present tray erector


100


is approximately 450 pounds, and is designed with caster


212


having brakes, to allow for easy movement and storage. Further, the relatively small size of the erector, in one embodiment 36′ long×28′ wide×64′ high, adds to the mobility for easily placing the erector in line with the product filler.




In use, the above-described blank


30


can be assembled to form a baking tray


10


as described, according to the above-described assembly method. Fluid contents, such as, for example, cake batter can be introduced to the interior of the baking tray


10


. Owing to the closed nature of the corners, as described above, the baking tray


10


resists leakage of any contents. The baking tray


10


can then be used for baking, storing and shipping products in a variety of applications. In addition, the flap panels


56


, which are folded outwardly and downwardly along the exterior of the first and second end walls


18


,


20


in the assembled configuration of the baking tray


10


provide convenient gripping edges for handling the assembled baking tray


10


, and do not interfere with the contents of the tray. The “roll-over lock” permits the tray to open and some of the contents to be removed, for example by a spatula, and re-locked by hand for storage.




While the invention has been disclosed in its preferred forms, it will be apparent to those skilled in the art that many modifications, additions, and deletions can be made therein without departing from the spirit and scope of the invention and its equivalents as set forth in the following claims.



Claims
  • 1. An automated erector for erecting an open top container having corners from a generally flat blank, the blank having a bottom panel bounded by end and side score lines, first and second end panels connected to the opposite ends of the bottom panel at the respective end score lines, first and second side panels connected to the opposite sides of the bottom panel at the respective side score lines, and corner webs adjacent each corner of the bottom panel between an adjacent end and side panel, each corner web having a top lock, each of the first and second end panels having a flap panel each flap panel connected to each end panel by a hinged fold joint having a retaining slit for receiving the top locks of the adjacent corner web, said erector comprising:(a) an inventory section including a hopper with a releasable retainer, said hopper capable of storing an inventory of stacked blanks; (b) a construction section including a setup assembly and a locking assembly, said construction section capable of transforming the blank into the open top container; (c) a transfer section that transfers a blank from said hopper to said construction section, said transfer section including a transfer mechanism to transfer the blank from a pick-up position to a release position; and (d) an exit section where an erected open top container exits the automated erector; said setup assembly of said construction section (b) being capable of folding the first and second end panels of the blank approximately 90 degrees from the plane of the bottom panel about the respective end score lines, and being capable of folding the first and second side panels of the blank approximately 90 degrees from the plane of the bottom panel about the respective side score lines, wherein while the first and second end and side panels are being folded, the corner webs extend out to form corner flaps each having a top lock; said locking assembly of said construction section (b) incorporating actuators with flippers mounted on said actuators, said flippers being capable of folding the corner flaps against the folded end panels, wherein the folding of the corner flaps provide the open top container with leakproof corners; and said locking assembly further incorporating a flap panel locking mechanism being capable of lowering the flap panel over the corner flaps so the top locks of the corner flaps are engaged in the retaining slit in the hinged fold joint.
  • 2. The erector of claim 1, further comprising:(a) a frame to which said sections are fixed; and (b) guards secured to said frame to protect an operator or observer from accidental entanglement with the operating and moving components of the erector.
  • 3. The erector of claim 1, wherein said transfer section (c) further comprises a grasping mechanism to releasably grasp a blank from said hopper at a pick-up position, wherein said transfer mechanism transfers a blank forward against bent flanges of said hopper at which point said grasping mechanism releases the blank.
  • 4. The erector of claim 3, wherein said exit section (d) comprises a moving delivery conveyor belt for transferring the erected open top container away from the automated erector.
  • 5. The erector of claim 4, wherein said exit section (d) further comprises a sensing mechanism to detect each erected open top container as it exits the automated erector.
  • 6. The erector of claim 5, wherein said exit section (d) further comprises a stabilizing device that stabilizes each exiting container so an exiting container does not interfere with subsequently exiting containers.
  • 7. The erector of claim 1, wherein said setup assembly of said construction section (b) comprises:(i) a ram assembly having a ram and an actuator, said actuator capable of moving said ram back and forth approximately normal to the blank between a retracted position and an extended position; (ii) side folders forming an aperture between which the blank is extended by said ram, said side folders folding the sides of the blank approximately perpendicular to the bottom panel of the blank; and (iii) an ejector plate; wherein when the blank is released from said grasping mechanism at the release position, the blank falls into said construction section and comes to rest upon a stop, such that the blank is positioned between said retracted ram and said ejector plate, and wherein, upon extension, said ram traps the bottom blank between said ram on one side and said ejector plate on the other.
  • 8. The erector of claim 7, wherein said setup assembly of said construction section (b) further comprises:(a) side tooling extenders that rotate said side folders so the side panels of the blank are folded beyond approximately perpendicular to the bottom panel of the blank; (b) end folders that fold the ends of the blank approximately perpendicular to the bottom panel of the blank; and (c) end tooling extenders that rotate said end folders.
  • 9. The erector of claim 8, wherein said flap panel locking assembly comprises locking bars, said locking bars rotationally driven about an axis parallel to the retaining slit by a bar extender.
  • 10. The erector of claim 9, wherein said side folders are curved to urge the side panels of the blank to fold about the side score lines while said ram continues to push the blank through the aperture between said side folders.
  • 11. An automated erector for erecting a tray having corners from a generally flat blank, the blank having a bottom panel bounded by end and side score lines, first and second end panels connected to the opposite ends of the bottom panel at the respective end score lines, first and second side panels connected to the opposite sides of the bottom panel at the respective side score lines, and corner webs adjacent each corner of the bottom panel between an adjacent end and side panel each corner web having a top lock, each of the first and second end panels having a flap panel flap panel connected to each end panel by a hinged fold joint having a retaining slit for receiving the top locks of the adjacent corner web, said erector comprising:(a) an inventory section including a hopper having bent flanges, a bottom guide and a tab stop capable of holding back a stack of blanks; (b) a construction section including a setup assembly and a locking assembly, said construction section capable of transforming the blank into the erected tray; (c) a transfer section that transfers a blank from said hopper to said construction section, said transfer section including a transfer mechanism to transfer the blank from a pick-up position to a release position; and (d) an exit section where the tray exits the automated erector; said setup assembly of said construction section (b) being capable of folding the first and second end panels of the blank approximately 90 degrees from the plane of the bottom panel about the respective end score lines, and being capable of folding the first and second side panels of the blank approximately 90 degrees from the plane of the bottom panel about the respective side score fines, wherein while the first and second end and side panels are being folded, the corner webs extend out to form corner flaps each having a top lock; said locking assembly of said construction section (b) incorporating actuators with flippers mounted on said actuators, said flippers being capable of folding the corner flaps against the folded end panels, wherein the folding of the corner flaps provide the tray with leakproof corners; and said locking assembly further incorporating a flap panel locking mechanism being capable of lowering the flap panel over the corner flaps so the top locks of the corner flaps are engaged in the retaining slit in the hinged fold joint.
  • 12. The erector of claim 11, further comprising:(a) a frame to which said sections are fixed; (b) guards secured to said frame to protect an operator or observer from accidental entanglement with the operating and moving components of the erector; and (c) movement means fixed to said frame to enable movement of the frame.
  • 13. The erector of claim 12, wherein said transfer section (c) further comprises a grasping mechanism to releasably grasp a blank from said hopper at a pick-up position, wherein said transfer mechanism transfers a blank forward against bent flanges of said hopper at which point said grasping mechanism releases the blank.
  • 14. The erector of claim 1, wherein said transfer section (c) includes a linked first and second transfer arm, and a transfer drive for rotating the linked transfer arms through a prescribed angle between the pick-up position and the release position over said construction section (b).
  • 15. The erector of claim 14, wherein said grasping mechanism comprises a releasable vacuum suction device.
  • 16. The erector of claim 15, wherein said exit section (d) comprises:(a) a moving conveyor belt; (b) a sensing mechanism to detect each tray as it exits the erector onto said conveyor belt; and (c) a stabilizing device that stabilizes each exiting tray so an exiting tray does not interfere with subsequently exiting trays.
  • 17. A method of folding a generally flat blank into a tray having corners with an automated erector, the blank having a bottom panel bounded by end and side score lines, first and second end panels connected to the opposite ends of the bottom panel at the respective end score lines, first and second side panels connected to the opposite sides of the bottom panel at the respective side score lines, and corner webs adjacent each corner of the bottom panel between an adjacent end and side panel each corner web having a top lock, each of the first and second end panels having a flap panel, with a flap panel connected to each end panel by a hinged fold joint having a retaining slit for receiving the top locks of the adjacent corner web, said method comprising the steps of(a) providing an inventory of blanks in a hopper having bent flanges and a tab stop, said hopper capable of storing an inventory of stacked blanks, said tab stop extending into contact with a bottom blank of the stacked blanks, holding back the stack of stacked blanks; (b) transferring the bottom blank of the inventory of blanks to a construction section, said step of transferring using a transfer mechanism to transfer the blank from a pick-up position to a release position and a grasping mechanism to releasably grasp the bottom blank at the pick-up position, wherein said transfer mechanism transfers the bottom blank forward against said bent flanges of said hopper where said grasping mechanism releases the bottom blank at the release position; (c) folding the first and second end panels of the blank approximately 90 degrees from the plane of the bottom panel about the respective end score lines, and folding the first and second side panels of the blank approximately 90 degrees from the plane of the bottom panel about the respective side score lines, wherein while the first and second end and side panels are being folded, the corner webs extend out to form flaps each having a top lock; (d) folding the corner flaps against the folded end panels with flippers mounted on actuators panels, wherein the folding of the corner flaps provide the tray with leakproof corners; and (e) folding each flap panel downward over the corner flaps so the top locks of the corner flaps are engaged in the retaining slit in the hinged fold joint.
  • 18. The method of claim 17, said step (c) of folding incorporating the use of:(i) a ram assembly having a ram and an actuator, said actuator capable of moving said ram back and forth approximately normal to the blank between a retracted position and an extended position; (ii) side folders forming an aperture between which the blank is extended by said ram, said side folders folding the sides of the blank approximately perpendicular to the bottom panel of the blank; and (iii) an ejector plate; wherein when the bottom blank is released from said grasping mechanism at the release position, the blank falls into said construction section and comes to rest upon a stop, such that the blank is positioned between said retracted ram and said ejector plate, and wherein, upon extension, said ram traps the bottom blank between said ram on one side and said ejector plate on the other.
  • 19. The method of claim 18, wherein said folding step (c) further comprises using:(a) side tooling extenders that rotate said side folders so the side panels of the blank are folded beyond approximately perpendicular to the bottom panel of the blank; (b) end folders that fold the ends of the blank approximately perpendicular to the bottom panel of the blank; and (c) end tooling extenders that rotate said end folders.
  • 20. The method of claim 19, wherein said folding step (e) further comprises using locking bars, each said locking bar capable of rotating each flap panel downward over the corner flaps, said locking bar rotationally driven about an axis parallel to the retaining slit by a bar extender.
  • 21. A method of foldably constructing a tray with an automated erector comprising the following steps:(a) providing a blank having leak-proof corner constructions, the blank having a bottom panel bounded by end and side score lines, first and second end panels connected to the opposite ends of the bottom panel at the respective end score lines, first and second side panels connected to the opposite sides of the bottom panel at the respective side score lines, and the leak-proof corner constructions, the corner constructions being corner webs adjacent each corner of the bottom panel between an adjacent end and side panel, each corner web having a top lock, each of the first and second end panels having a flap panel, with a flap panel connected to each end panel by a hinged fold joint having a retaining slit for receiving the top locks of the adjacent corner webs; (b) folding the first and second end panels and the first and second side panels of the blank with the automated erector, the automated erector folding the first and second end panels of the blank approximately 90 degrees from the plane of the bottom panel about the respective end score lines, and folding the first and second side panels of the blank approximately 90 degrees from the plane of the bottom panel about the respective side score lines, wherein while the first and second end and side panels are being folded, the corner webs extend out to form flaps each having a top lock; (c) folding the leak-proof corner constructions with the automated erector against the folded end panels such that the corner constructions remain leakproof upon folding; and (d) folding downward each flap panel, and over the corner flaps, with the automated erector so the top locks of the corner flaps are engaged in the retaining slit in the hinged fold joint.
  • 22. The method of claim 21, said step (c) of folding the leak-proof corner constructions incorporating the use of actuators with flippers mounted on said actuators, said flippers being capable of folding the leak-proof corner constructions against the folded end panels.
  • 23. The method of claim 21 further comprising the step (e) storing an inventory of the blanks in a hopper, the inventory of stacked blanks including a bottom blank being the blank of step (a), the bottom blank being folded through said steps (b), (c) and (d).
  • 24. The method of 21 further comprising the step (e) of exiting the foldably constructed tray from the erector, said exiting step (e) incorporating a movable conveyor belt, a sensing mechanism to detect each tray as it exits the erector onto said conveyor belt, and a stabilizing device that stabilizes each exiting tray so an exiting tray does not interfere with subsequently exiting trays.
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