ACTIVE COMPRESSION ADHESIVE PACKAGING METHOD AND APPARATUS

Abstract

A method and system for packaging products in a container employs an active compression assembly having pressure members which are shifted from a raised position to a lowered operational position. In the operational position, each pressure member holds a respective upper container flap against a lower container flap while an interposed adhesive sets. More specifically, with the at least one pressure member pushing upon the upper flaps, both the container and the at least one pressure member are forced to move in unison along a manufacturing line while the at least one pressure member applies pressure on the upper flaps as the adhesive sets to seal the upper flaps to the lower flaps and close the upper opening.

Description

FIELD OF THE INVENTION

The invention pertains to the art of packaging and, more particularly, to packaging various products, such as food products, in containers or cases having folding upper and lower flaps which are adhesively attached to close the container.

BACKGROUND OF THE INVENTION

Numerous manufactured products are pre-packaged, either individually or in groups, and then a plurality of the pre-packaged products are packaged in a larger container and shipped to a wholesaler who unpacks the container and places the pre-packaged products on display shelves for purchase by consumers. In particular, it is common to package a wide range of products in containers having folding flaps, such as cardboard boxes. Often in the manufacturing of products at many existing facilities, the pre-packaging of the products is performed by automated equipment, while the packaging of the various products into a larger container for shipping or storage purposes is performed manually. For instance, it is still commonplace for manufactured products to be conveyed to an assembly line region supplied with containers wherein assembly workers manually fill and seal the containers for shipping. However, in other situations, shipping containers can be loaded and sealed using automated machinery.

When utilizing cardboard boxes, each box is generally erected, either manually or with the use of machinery, to erect the box so as to create a packaging chamber having an open top which can be closed by folding minor and major flaps. Once the box is erected, the chamber can be filled with products, either pre-packaged or not, and then the minor and major flaps are folded for shipping. Of course, it is desirable to prevent the box from opening prior to reaching its destination such that it is common practice to seal the flaps. Basically, two methods are almost universally employed to perform this sealing function. The first is to externally apply adhesive tape along seams of the major flaps, with the tape generally being in the order of a couple inches in width and extending across the top and onto opposing sides of the box. The other approach is to apply an adhesive to the upper surfaces of the minor flaps after they are folded, then fold the major flaps onto the minor flaps so that the adhesive is also placed in contact with the major flaps, and finally compress the major flaps onto the minor flaps for a period of time to enable the adhesive to set to a certain extent.

This second approach is considered advantageous in that it can be more readily automated. Unfortunately, there are at least two potential problems associated with this sealing method. The first problem only arises if the products being packaged are not solid in nature. That is, when the products being packaged are both generally solid in nature and fill the box to the fold seams associated with the flaps, the box can be easily sealed in this manner as the products provide the back pressure needed to hold the major flaps against the minor flaps while the adhesive sets. An example of such an arrangement would be packaging reams of paper in a box. However, if the products are not solid in nature, the products cannot provide the back pressure necessary to enable the major flaps to be adequately compressed against the minor flaps such that the seal is inherently compromised. For instance, various products are pre-packaged with considerable headspace, including a wide range of food products such as bags of potato chips, frozen vegetables, frozen biscuits, marshmallows and the like, which prevent the products from providing the requisite back pressure. The other problem concerns the downtime associated with sealing a box in this manner. That is, although quick dry adhesives are commonly employed, the boxes being sealed need to be paused during the overall manufacturing process, such as for about 5-10 seconds, during which time flap static bars hold the flaps in the folded position until the adhesive sets. Certainly, incorporating a mandatory pause in a portion of a manufacturing operation is not optimal.

Based on the above, there is seen to still exist a need for an more efficient way of adhesively sealing packaging boxes in a manufacturing operation wherein the box sealing operation can occur in a continuous process. In particular, there exists a need for a packaging operation, which can be employed in connection with products which do not terminate directly adjacent flap seams of the boxes and/or do not provide the requisite back pressure needed for forcibly sealing the flaps, while also enabling the flaps of boxes to be adhesively sealed in a continuous operation.

SUMMARY OF THE INVENTION

The invention is directed to a method and system for packaging products in a container, defining a compartment with an upper opening which can be closed by adhesively securing foldable upper flaps upon lower flaps, along a manufacturing line. In accordance with the method and system of the invention, at least one pressure member of an active compression assembly is shifted from a raised, home position to a lowered, operational position against the upper flaps. In the operational position, each pressure member holds a respective upper flap against a lower flap while the interposed adhesive sets. More specifically, with the at least one pressure member pushing upon the upper flaps, both the container and the at least one pressure member are forced to move in unison along the manufacturing line while the at least one pressure member applies pressure on the upper flaps as the adhesive sets to seal the upper flaps to the lower flaps and close the upper opening. To assure the unison movement, a leader member, which is attached to the at least one pressure member, is positioned against a frontal portion of the container for a predetermined distance along the manufacturing line. Thereafter, the leader member is shifted to a retracted position and the at least one pressure member is shifted away from the upper flaps such that the entire system can be shifted back to a home position for use in closing a subsequent container.

In operation, an open, assembled and loaded container is directed to a terminal portion of the manufacturing line wherein the lower flaps are folded, followed by the application of adhesive to surface portions of the lower flaps and then folding of the upper flaps. At this point, the position of the container is sensed such that, as it reaches and engages the leader member, the pressure member(s) of the active compression assembly is lowered against the upper flaps. Thereafter, the pressure member(s) engages the container, the pressure member(s) and the container continue down the line in unison. During this time, the force exerted by the pressure member(s) can be increased by further lowering the same. After the container reaches another predetermined position, the leader member is retracted from in front of the container and the active compression assembly is repositioned to act on another container. In this manner, an automatic, continuously operating active compression operation is performed to assure a high quality seal of the container flaps.

Additional objects, features and advantages of the invention will become more readily apparent from the following detailed description when taken in conjunction with the drawings wherein like reference numerals refer to corresponding parts in the several views.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a terminal portion of a manufacturing line including the packaging system of the invention, with a container being shown in an initial closing stage.

FIG. 2 is a perspective view of the terminal portion of FIG. 1 illustrating the container in an intermediate closing stage.

FIG. 3 is a perspective view of the terminal portion of FIG. 1 illustrating the container in a final stage.

FIG. 4 is a perspective view of an active compression assembly employed in the packaging system of FIGS. 1-3.

FIG. 5 is a partial exploded view of the active compression assembly of FIG. 4.

DETAILED DESCRIPTION OF EMBODIMENTS

With initial reference to FIG. 1, a terminal portion of a manufacturing line is generally indicated at 5. As shown, terminal portion 5 includes upstanding support framework 8 and a substantially horizontal support framework 10. Horizontal support framework 10 rotatably supports a plurality of rollers 13, as well as a pair of side housings 18 and 19 in which are positioned endless side belts 22 and 23 driven by respective motors (not shown). As also illustrated in this figure, terminal portion 5 is provided with a pair of opposing side guide rollers, one of which is indicated at 27, as well as a pair of upper guide rollers, one of which is indicated at 29.

As will be described more fully below, a container 33 is adapted to be loaded and directed down terminal portion 5 where it is sealed in a final packaging stage of an overall manufacturing process. Although container 33 can be made of various materials, including cardboard, container 33 includes a bottom 36 and opposing sets of upstanding sides 38, 39 which define a compartment or chamber (not labeled) with an associated upper opening 42. Upper opening 42 can be closed by folding a pair of lower or minor flaps 45, followed by a pair of upper or major flaps 46. More specifically, as will be detailed more fully below, lower flaps 45 are initially folded along side seams (not labeled) and then, after an application of hot melt adhesive upon lower flaps 45, upper flaps 46 are folded and adhesively secured in order to close upper opening 42. To this end, container 33 is initially loaded with various products 53 prior to reaching terminal portion 5. At this point, it should be recognized that container 33 can be designed to receive a wide variety of products 53. However, for reasons which will be more fully evident below, the present invention is particularly advantageous for use in combination with products 53 which are not loaded all the way up to the fold seams for lower and upper flaps 45, 46 and/or are prepackaged in bags or the like with the inclusion of head space, e.g., bags of potato chips, pretzels, frozen vegetables, frozen biscuits, marshmallows and the like, such that products 53 cannot provide the requisite back pressure upon lower flaps 45 needed to prevent lower flaps 45 from pivoting within container 33 beyond a substantially horizontal position. In any case, as container 33 reaches terminal portion 5 full of products 53, container 33 reaches a lower flap folding mechanism 56 which functions to engage and fold lower flaps 45 into a substantially horizontal plane as generally indicated in this figure. Although lower flap folding mechanism 56 can take various forms in accordance with the invention as such flap folding mechanisms are known in the art, the preferred embodiment employs one or more vertically moving arms, such as that indicated at 59, which, timed with the movement of container 33 along the manufacturing line, abuts and pushes down lower flaps 45 to the folded position. Subsequent to the folding of lower flaps 45, container 33 reaches an adhesive dispenser 62 which applies a predetermined amount of a hot melt adhesive 63 upon lower flaps 45. Thereafter, continued movement of container 33 upon rollers 13 causes upper flaps 46 to engage upper flap folding arms 64. At this point, it is the intent that upper flap folding arms 64 will cause upper flaps 46 to fold over at least portions of lower flaps 45 with the hot melt adhesive 63 therebetween such that upper flaps 46 will be attached to lower flaps 45 in order to close upper opening 42 of container 33.

In accordance with the invention, an active compression assembly generally indicated at 75 is added to terminal portion 5 of the manufacturing line in order to ensure that upper flaps 46 are positively engaged with lower flaps 45 during a critical period in which adhesive 63 sets, thereby ensuring that upper opening 42 is adequately sealed such that additional tape over upper flaps 46 is not necessary. With particular reference to FIGS. 4 and 5, active compression assembly 75 will now be detailed. In the illustrated embodiment, active compression assembly 75 includes an upright support 78 from which extends a cantilevered arm 82. A gusset plate 83 interconnects upright support 78 and cantilevered arm 82 for additional support. Mounted to cantilevered arm 82 is a rail or track 87 upon which is slidably mounted a guide unit 90. As shown, guide unit 90 includes a grooved plate 93 which mates with rail 87. Although not shown for the sake of simplicity of the drawings, an additional grooved plate is positioned on the other side of rail 87 and is interconnected with groove plate 93 to clamp guide unit 90 for sliding movement along rail 87. In addition, the structure of rail 87 and/or groove plate 93 can be made of a low friction material or various rollers, bearings or the like can be interposed therebetween in order to ease the linear shifting of guide unit 90 along rail 87. As movement of guide units along rails are widely known in the manufacturing field and this is not considered to be a particular aspect of the present invention, further details thereof will not be provided here. More importantly, guide unit 90 also includes a housing 96 that is fixed relative to plate 93 and formed with a pair of spaced bores 103 and 104. Spaced bores 103 and 104 slidably receive guide bars 107 and 108 that are attached to a vertically displaceable base plate assembly 112. A first drive mechanism 116 is interposed between housing 96 and base plate assembly 112 to vertically shift base plate assembly 112 relative to housing 96. More specifically, first drive mechanism 116 includes a linear actuator 119 defined by a cylinder 122 and a piston rod 125. At this point, it should be recognized that linear actuator 119 can take various forms in accordance with the invention, including pneumatic, hydraulic and electric solenoid-type linear actuators. Therefore, it is only important to note that first drive mechanism 116 provides for the selective vertical shifting of base plate assembly 112 relative to housing 96 and rail 87.

Also carried by base plate assembly 112 is a second drive mechanism 130. Second drive mechanism 130 is also defined by a linear actuator including a cylinder 136, which is fixed relative to base plate assembly 112, and a piston rod 139 which is movable relative to cylinder 136. Piston rod 139 is attached by means of a pin 143 to a pair of arms 146 and 147 extending from a rod 149 that is rotatably mounted in a pair of leg members 152 and 153 secured to base plate assembly 112. Also extending from rod 149 for concurrent rotation therewith is a leader member or drag arm 156. In the embodiment shown, leader member 156 includes a main body 158 and a terminal abutment member shown in the form of an extruded metal tube 160. With this arrangement, extension and retraction of piston rod 139 relative to cylinder 136 causes arms 146 and 147, as well as rod 149 and leader member 156, to rotate about an axis defined by rod 149. More specifically, retraction of linear actuator 133 from the extended position shown in this figure causes leader member 156 to shift from a substantially vertical plane as depicted to a substantially horizontal plane.

As will be detailed more fully below, active compression assembly 75 is employed to provide pressure upon upper flaps 46 during a critical drying period for adhesive 63, thereby providing an enhanced interconnection between upper and lower flaps 46 and 45. In addition, it is desirable to construct active compression assembly 75 in a manner which will accommodate varying sized containers 33. In accordance with these aspects of the invention, base plate assembly 112 includes a main portion 168 formed with a plurality of spaced openings 171. A respective pressure member 175 is mounted in each of the openings 171 as will be discussed further below. Each side of main portion 168 is also provided with an elongated slot 185 which generally extends in the direction of rail 87. Portions of each slot 185 are aligned with a slot 188 in a respective extension arm 190, with each extension arm 190 receiving an additional pressure member 193 in a respective opening 171. With slots 185 and 188 aligned, a respective bolt 196 extends through the slots so as to secure extension arm 190 to main portion 168. With the provision of slots 185 and 188, or an analogous arrangement including a plurality of holes, it should be readily apparent that extension arms 190 can be mounted at various angular positions and to establish different distances between the plurality of pressure members 175, 193. In this fashion, base plate assembly 112 can be readily reconfigured for different size containers 33.

It is the function of pressure members 175 and 193 to apply downward forces upon upper flaps 46 to ensure a positive pressure between upper flaps 46 and lower flaps 45 during a critical setting period for the adhesive. For this purpose, each of the pressure members 175 is preferably made of a resilient material, such as an elastomeric or rubber material. More specifically, each pressure member 175 includes a head 202, a shank 204 and a flexible finger portion 206. Flexible finger portion 206 is inserted into a respective opening 171 and shank portion 204 preferably defines a reduced diametric portion (not labeled) directly adjacent head 202, with the reduced diametric portion being slightly greater than the thickness of either main portion 168 or extension arm 190. In this fashion, each pressure member 175 can be frictionally maintained in place by simply pulling on shank portion 204 until head 202 is positioned against either main portion 168 or extension arm 190. In any case, finger portion 206 is made more flexible than shank 204 and therefore will resiliently bend to apply the desired pressure as will be described in detail below. In the embodiment shown, the controls associated with active compression assembly 75 are pneumatic in nature such that various air hoses 225-229 are illustrated in FIGS. 1-3, including hoses extending to linear actuators 119 and 133.

As discussed above, in the position shown in FIG. 1, container 33 has lower flaps 45 folded in and adhesive dispenser 62 has applied the adhesive 63 thereon. Container 33 then proceeds wherein upper flaps 46 engage folding arms 64. At this point, container 33 reaches the position shown in FIG. 2 where a frontal portion of container 33 abuts terminal abutment member 160 of leader member 156, with main body 158 of leader member 156 extending substantially vertically. At this time, linear actuator 119 of first drive mechanism 116 is activated such that piston rod 125 is extended and base plate assembly 112 shifts relative to housing 96 such that the plurality of pressure members 175 and 193 come into engagement with predetermined sections of upper flaps 46. Given the construction of base plate assembly 112 as described above, the exact position of at least pressure members 193 can be readily adjusted. In the present case wherein lower flaps 45 do not extend the entire width of container 33 as clearly shown in these figures, extension arms 190 are angled inwardly such that pressure members 193 abut adjacent centerline portions of upper flaps 46, while pressure members 175 abut more central portions of upper flaps 46. Given the resilient nature of pressure members 175 and 193, the downward movement of base plate assembly 112 causes flexible finger portions 206 to bend, thereby applying the requisite degree of pressure for setting of adhesive 63.

In accordance with a preferred embodiment of the invention, it is desired to time the positioning of container 33 with the movement of first drive mechanism 116 such that a sensor 255 is employed to detect a frontal edge portion of container 33 along terminal portion 5 of the manufacturing line. In the embodiment shown, a photo eye 256 cooperates with a reflector 258 to sense this leading edge. However, it should be understood that various types of sensor systems, including switches, could be employed. Once active compression assembly 75 is engaged with container 33, container 33 reaches endless side belts 22 and 23 to carry the container 33 to the terminal portion 5 of the manufacturing line. At the same time, guide unit 90 carries base plate assembly 112 along rail 87 in unison with the movement of container 33. Although guide unit 90 could be driven in this direction by endless side belts 22 and 23 and container 33 given the abutment between container 33 and leader member 156, the most preferred form of the invention provides a separate linear drive mechanism, such as a horizontal, rodless air cylinder (not shown), to move guide unit 90 along rail 87 in unison with container 33. In accordance with one aspect of the invention, a progressively increasing vertical application pressure is applied to vary the force exerted by pressure members 175 and 193 upon container 33 as base plate assembly 112 is guided along rail 87 as evident in comparing at least FIGS. 2 and 3. Upon reaching the end of its operational movement, second drive mechanism 130 is activated to rotate leader member 156, while first drive mechanism 116 functions to vertically shift pressure members 175 and 193 out of engagement with upper flaps 46 and active compression assembly 75 is returned to the ready position shown in FIG. 1. To signal these operations, it is desirable to provide a second sensor generally indicated at 275. In the configuration shown, second sensor 275 is constituted by a switch 276 that becomes engaged with an abutment member 278 carried by housing 96 of guide unit 90. In other embodiments, different sensors, such as another photo eye, could be employed.

Based on the above, it should be readily apparent that the active compression assembly of the invention enables at least one pressure member to be shifted from a raised, home position spaced from the upper flaps of the container to a lowered, operational position in which the pressure member abuts and applies pressure to respective upper flap in order to hold the upper flap in a desired position while the adhesive between the upper and lower flaps sets. During this period of positive pressure, both the container and the pressure member move in unison along the manufacturing line until a predetermined point where the pressure member is moved away from the upper flap and back to the home position. As it is not desirable for the pressure members to slide relative to the container during this operation, the leader member is provided to prevent the container from moving at a faster pace than the base plate assembly of the active compression assembly. That is, the leader member is maintained in an active position during the concurrent movement and then is shifted to a retracted position to enable the active compression assembly to be repositioned for use in closing a subsequent container coming down the manufacturing line. Again, although the invention can be employed in connection with containers which are filled up to the fold lines for the upper and lower flaps and which could provide back pressure to enable the upper flaps to be pushed against the lower flaps without deflection of the lower flaps, the invention finds particular applicability for use in sealing containers which are filled with products that cannot provide the requisite back pressure. In such an arrangement, it is desired to mount the pressure members generally close or only slightly spaced from the fold lines of the lower flaps, thereby minimizing any undesirable added deflection of the lower flaps while still assuring a positive pressure between the upper and lower flaps for setting of the adhesive. It has been found that the invention is extremely productive in ensuring that a strong adhesion is created between the upper and lower flaps such that additional taping of the container is not necessary.

Although described with reference to certain embodiments of the invention, it should be readily understood that various changes and/or modifications can be made to the invention without departing from the spirit thereof. For instance, the type of product, the container material, the location, mounting and structure of the pressure members, and also the exact drive and interaction between the active compression assembly and the container can be altered without departing from the invention. Instead, the invention is only intended to be limited by the scope of the following claims.

Claims

1. A method of packaging products comprising:

directing a container, defining a compartment with an upper opening which can be closed by folding upper and lower flaps, along a manufacturing line;

positioning a plurality of products in the compartment of the container;

folding a lower flap over a portion of the upper opening;

folding an upper flap upon the lower flap with adhesive there between;

shifting at least one pressure member of an active compression assembly from a home position spaced from the upper flap to an operational position against the upper flap;

directing both the container and the at least one pressure member to move in unison along the manufacturing line while the at least one pressure member applies pressure on the upper flap as the adhesive sets to close the upper opening; and

shifting the at least one pressure member away from the upper flap and moving the active compression assembly back to the home position for use in closing a subsequent container.

2. The method of claim 1, wherein the adhesive is applied to the lower flap following the folding of the lower flap and prior to the folding of the upper flap upon the lower flap.

3. The method of claim 1, wherein shifting the at least one pressure member comprises moving a plurality of spaced fingers into engagement with the upper flap.

4. The method of claim 3, wherein the plurality of spaced fingers are vertically shifted into engagement with the upper flap.

5. The method of claim 3, further comprising: selectively adjusting a spacing between the plurality of spaced fingers.

6. The method of claim 3, further comprising: resiliently biasing the plurality of spaced fingers into engagement with the upper flap.

7. The method of claim 1, further comprising: shifting a leader member into a ready position for engagement with a frontal portion of the container to assure that both the container and the at least one pressure member move in unison along the manufacturing line.

8. The method of claim 7, further comprising: pivoting the leader member from a retracted position to the ready position.

9. The method of claim 1, further comprising: linearly guiding the at least one pressure member along a track while both the container and the at least one pressure member move in unison along the manufacturing line.

10. The method of claim 1, wherein positioning the plurality of products in the compartment of the container constitutes loading the container with sealed packages having headspaces such that the sealed packages do not provide any significant back pressure to the upper and lower flaps when closing the container.

11. The method of claim 10, wherein closing the container constitutes sealing a cardboard box.

12. A system for closing an upper opening of a container defining a compartment in which is positioned a plurality of products, the system comprising:

at least one pressure member;

a first mechanism drivingly connected to the at least on pressure member of an active compression assembly for moving the at least one pressure member from a first position spaced from the container to a second, operational position wherein the at least one pressure member engages an upper flap of the container to force the upper flap towards a lower flap of the container with an adhesive there between; and

a second mechanism connected to the at least one pressure member and causing both the container and the at least one pressure member to move in unison along a manufacturing line while the at least one pressure member applies pressure on the upper flap as the adhesive sets to close the upper opening, wherein the first mechanism can reposition the at least one pressure member away from the upper flap and the second mechanism can move the active compression assembly back to a home position for use in closing a subsequent container.

13. The system of claim 12, wherein the at least one pressure member comprises a plurality of spaced fingers.

14. The system of claim 13, wherein the first mechanism shifts the plurality of spaced fingers vertically into engagement with the upper flap.

15. The system of claim 13, wherein the active compression assembly includes first and second, adjustably connected plates, wherein at least one of the plurality of spaced fingers is attached to the first plate and another of the plurality of spaced fingers is attached to the second plate, said second plate being adjustably attached to the first plate to vary spacings between the plurality of spaced fingers.

16. The system of claim 13, wherein each of the plurality of spaced fingers is formed of a resilient material.

17. The system of claim 12, wherein the active compression assembly further comprises a leader member mounted for movement between a ready position for engagement with a frontal portion of the container and a non-engaging, retracted position.

18. The system of claim 17, wherein the leader member is pivotable between the ready and retracted positions.

19. The system of claim 17, further comprising: a sensor for sensing the frontal portion of the container at a predetermined location along the manufacturing line, with movement of the leader member being dependent on the frontal portion being sensed.

20. The system of claim 12, further comprising: a sensor for sensing a position of the active compression assembly along the manufacturing line, with movement of the second mechanism back to the home position being dependent on the position of the active compression assembly.

21. The system of claim 12, wherein the active compression assembly includes a track member, said at least one pressure member being mounted for linear movement along the track member.

22. The system of claim 12, wherein the container constitutes a cardboard box and each of the products is constituted by a sealed package including a headspace.