AUTOMATIC PACKAGING MACHINE REPLENISHING METHOD AND APPARATUS

Description

BACKGROUND OF THE INVENTION

Packaging machines are well-known in the art, an omnipresent necessity in a consumer driven economy in which billions of consumer products are packaged and boxed every year. A vast array of packaging machine styles and assemblies include the use of blanks such as cardboard or paperboard blanks including pre-glued cartons, that are opened, folded, bent, glued, or otherwise constructed into cartons or boxes, containing articles of manufacture. Packaging machines also frequently include provisions for inserting flat items, such as information sheets, inserts, cards or spacers into a package along with the product being packaged. The present invention contemplates a general supply of flat items, whether they be blanks or inserts or sheets or cards, that will be supplied from a feed stack held in a magazine, with the packaging machine picking such a flat item from the feed stack in the magazine for the package being created.

As the packaging machine creates packages, beginning with picking a flat item from the magazine, the feed stack of the flat items in magazine becomes depleted and must be replenished, and it is preferable that the replenishment occur continuously without requiring shut down of the packaging machine. There is a vast variety of systems and methods for replenishing packaging machine magazines in the prior art. Traditionally, replenishment of the magazine has been done manually, with a machine operator periodically loading a new stack of flat items into the magazine. In many manual systems, operation of the magazine is interrupted to reload or replenish the stack of flat items in the magazine. Modern high-speed and high-volume packaging machines have automated the process of reloading the magazine, including the use of robots that will grab a stack of flat items from a supply pallet and load them on demand into the packaging machine magazine.

Whether done manually or through robotic or automatic loading, the replenishment of flat items into a magazine is performed in a variety of ways. There are a number of prior art solutions wherein the flat items are vertically stacked, with the packaging machine picking an item from the top of the stack, with typically a spring loaded or driven pressure plate device, pushing the stack up from the bottom until it is depleted. To reload flat items into a vertical stack it is necessary to either pause the machine operation and add flat items to the top of the stack, pushing the lower pressure plate to accommodate the added blanks or, if the blanks are added to the bottom of the stack, it is necessary to support the remaining items in the stack and retract and reinsert the lower pusher plate such that it pushes up against the newly added flat items on the bottom of the vertical stack. In either case, it is a complicated maneuver that will almost certainly cause interruption of the packaging process. Within this application, “blank” will be used to generically refer to a pre-glued carton, or a flat item, such as a blank, sheet, or card insofar as, for purposes of magazine replenishment operations the principles of handling each such class of item is the same.

Other packaging machine magazines provide for horizontal orientation of the stack of blanks such that said blanks are substantially vertically oriented with supporting structure to keep the stack from tending to fall over at the ends and the stack flowing toward a “picker” device that grabs the next blank from the flowing stack in any of a variety ways, mechanically or using a suction device or using an overdrive belt or wheel to accelerate and separate a single blank away from the stack, and then moves the blank into the packaging machine for further processing, whether the blank requires folding, bending, gluing, or construction into a box or carton or whether the blank is actually a sheet or card or spacer inserted into the package.

Horizontally oriented magazines make picking of the blanks simple as described above, but as the blanks in the stack are consumed and the magazine has to be replenished, it is desirable to replenish the horizontal stack with a new supply stack of blanks without interruption of the packaging machine, even as the flowing stack of blanks continues to be depleted as it has blanks picked from it and moved into the packaging machine for further processing. To load an additional supply stack of blanks into a horizontally oriented flowing stack of substantially vertically oriented blanks in the magazine, it is necessary to orient the new supply stack of blanks horizontally, such that the blanks themselves are substantially vertically oriented, similar to the blanks in the flowing horizontal feed stack onto which the new supply stack will be added. The substantially vertically oriented blanks in the flowing stack horizontal stack are supported at the tail end with a removable support device to prevent the last few blanks from falling over until the new supply stack of vertically oriented blanks are positioned adjacent to the tail end of the flowing stack, at which point the removal support device is removed, the blanks of the new supply stack now supporting the former tail end of the flowing stack in a substantially vertical orientation, such that the new supply stack of vertically oriented blanks becomes integrated into the flowing stack. The removable support device is then relocated to the new tail end of the flowing stack after integrating the supply stack into the flowing stack. Typically, the removable support device holding the last few blanks at the tail end of the flowing stack in a substantially vertical orientation is a spring loaded pressure plate that is positioned at the tail end of a horizontal flowing stack and provides pressure and supports the last few vertically oriented blanks, the spring loaded pressure plate being removed to allow the new supply stack of blanks to be integrated into the flowing stack, and the spring loaded pressure plate is then repositioned at the new tail end of the flowing stack.

A wide array of prior art packaging machines utilizing a horizontal magazine have implemented a method and structure wherein the blanks propagate through the magazine at a slight angle to vertical, rather than being perfectly upright. Typically, the blanks in the magazine have a lean angle of 10° to 30° to the horizontal to allow them to be advanced through the magazine to where they will be “picked” by the picker and forwarded to the packaging machine for further processing. A number of advantages are achieved by providing the forward lean angle for the blanks, including eliminating the need for an end follower to maintain the orientation of the flowing stack of blanks and to keep the items in the flowing stack from falling over as the flowing stack moves forward. In light of the fact that packages come in such a vast assortment of sizes and shapes, packaging machines and flat items, blanks, sheets and cards also come in a wide variety of sizes and shapes, and it is desirable to provide a magazine for packaging machines that is adaptable to handle a variety of sizes and arrangements of flat items, blanks, sheets and cards that can be used across a variety of machines. It is important to consider the structure, weight, rigidity and other characteristics of the blanks processed through the magazine, and often will require adjustment of the lean angle at which they are maintained. For example, a heavy corrugated sheet of cardboard will require a much different lean angle to maintain the desired vertical orientation as opposed to a thin sheet of glossy paper that will be processed to be inserted into a package. It is desirable to provide a single magazine handler that can accommodate a variety of blanks/items to be included in the packaging operation.

The main problem of introducing a refill and replenish stack into the magazine is that it is desirable to introduce it at the same lean angle at which the existing stack of blanks is being processed. The flowing stack of blanks that are being consumed by the packaging machine are maintained at an optimal angle for introduction into the packaging machine, and for picking the next blank. Introducing a new supply or replenishment of blanks into the flowing stack requires either the placement of the blanks behind the flowing stack at the same angle, or the introduction of a resupply/replenishment of blanks that are vertically oriented, and then allowed to fall over onto the back, tail end of the flowing stack. Both scenarios present difficulties that often result in machine malfunction. It is desirable that the tops of the blanks in the magazine are maintained at a constant level elevation. It has been found that if the replenishing stack of blanks is introduced at too shallow of an angle, the level across the tops of the blanks drops. If the replenishing stack of blanks is introduced at too steep an angle, the level across the tops of the blanks also rises, disadvantageously. These conditions will both cause downstream problems when the blanks are picked one a time to go into the packaging machine.

The present invention, as will be set forth in more detail herein provides an adjustable support plate with a corresponding angle of inclination relative to horizontal, upon which both the flowing stack and a standby stack, a prime stack of blanks, will be placed. That is, there is a flowing stack from which blanks are picked and the stack moves forward, while a prime stack, positioned and oriented and held in a standby position, is prepared to replenish the flowing stack, and both the flowing stack and the prime stack are provided on a support plate and maintained at the same angle determined by the angle of the inclination of the support plate. This is possible by providing an adjustably angularly inclined support plate as part of the magazine.

The present invention alleviates the significant problem of loading blanks into a packaging machine at an optimal lean angle, and replenishing the supply of blanks at that angle, by providing an angularly inclined support plate as part of the magazine, wherein a prime stack of replenishing blanks is seamlessly moved into the flowing stack. This is done in a manner such that machine operation is not interrupted, there is no surge or push on the tail end or elsewhere on the flowing stack when the new blanks are inserted into the magazine, and the optimal angle is maintained in the prime stack and flowing stack throughout the process of being fed into the packaging machine.

As is known in the art, the present invention utilizes a robot to select cases of blanks from a pallet and will then move them into the packaging machine magazine. In a common example the blanks are held within a case and a robot depalletizer selects a case and then upends it to allow the blanks to be placed upon the support. In the most applicable embodiment, the robot utilizes a flat bottom plate and a flat top plate that sandwich the case and the blanks contained therein, retaining all of the blanks within the case, The robot then flips the case upside down as it is relocating it to the desired location at the magazine so that, upon removal of the plates, the blanks are free to fall from gravity onto the angularly inclined magazine support plate. The case is then lifted off the blanks and removed so that the new supply of blanks exist in a substantially vertical orientation in a substantially horizontal stack in the magazine.

By providing a lane for the flowing stack of blanks being consumed by the packaging machine in parallel to a lane for a prime stack of planks right next to it, it is possible to deplete the flowing stack until a sensor detects that the flowing stack is sufficiently depleted, at which point the prime stack is seamlessly pushed into the flowing stack without interrupting the flow of the flowing stack or the operation of the packaging machine. The angularly inclined support plate on which both the flowing stack and the prime stack are maintained is specifically oriented to use desirable gravitational force down the low friction inclined surface to keep the flowing stack blanks moving down the into a curved transition section and ultimately into the packaging machine while also maintaining the flowing stack lean sufficiently upright that the last few blanks at the tail end of the flowing stack to not fall from their substantially vertical orientation. An automatically movable follower mechanism may be applied to the tail end of the flowing stack to ensure that the last blanks in the flowing stack are maintained in a substantially vertical until the blanks from the prime stack are pushed over into the flowing stack lane to engage and support what had been the tail end of the flowing stack. By maintaining the prime stack on the inclined support plate at the same angle as the flowing stack, when the time comes for moving the prime stack blanks into the flowing stack lane, a simple lateral push of the prime stack from the parallel prime stack lane into the flowing stack lane allows a seamless and uninterrupted replenishment of the magazine, so that no interruption of the packaging machine is necessary. In the event that a follower is applied at the rear of the flowing stack, as discussed above, the follower is disengaged to allow the prime stack blanks to be pushed into the flowing stack and then reengages upon receiving a signal that the prime stacker pusher bar has returned to its position adjacent the prime stack lane.

OBJECTS OF THE INVENTION

It is an object of the present invention to provide an improved automatic magazine loader for use with packaging machines.

It is another object of the present invention to provide a packaging machine magazine assembly that is adjustable to accommodate different size, shape, weight, and characteristics of blanks, sheets, cards and flat items.

It is yet another object of the present invention to provide a automatic magazine loader that provides for the replenishment of blanks with an identical lean angle for newly supplied blanks to that of the flowing stack of blanks.

It is another object of the present invention to provide a packaging machine magazine loader that automatically detects depletion of the flowing stack of blanks and triggers replenishment of the flowing stack with blanks from a standby prime stack, and subsequently automatically calls for the automatic replenishment of the prime stack.

It is yet another object of the present invention to provide an automatic magazine loader for a packaging machine that is adjustable for corrugated cardboard blanks, paperboard blanks, single sheet card insertions, and other flat items included in the construction and filling of a package.

SUMMARY OF THE INVENTION

The present invention comprises a method and apparatus for loading blanks into a packaging machine. The method comprises multiple discrete steps including, first, providing a magazine support plate having a flowing stack lane area and a prime stack lane area. The next step is to position a flowing stack of blanks in the flowing stack lane area and to position a prime stack of blanks in the prime stack lane area. As the machine operates and the flowing stack is consumed, the next step in the method is the detecting of a low limit of blanks in the flowing stack and, upon such detection, moving blanks from the prime stack lane into the flowing stack lane. The final step occurs upon the detection of an absence of blanks in the prime stack lane when then triggers the robot to pick another case of blanks and then to load a new supply of blanks into the prime stack lane.

In the most preferred embodiment of the invention, the method also includes the step of orienting the magazine support plate at an optimal angle for the specific parameters of the blanks being used. The present inventive method contemplates the providing of a magazine support plate having a low friction surface intended to facilitate the gravity feeding of blanks in the angularly inclined flowing stack.

Further, the method contemplates the flowing stack being oriented parallel and next to the prime stack lane such that the moving of blanks into the flowing stack lane comprises pushing blanks from the prime stack lane across the low friction surface into the flowing stack lane.

In the most preferred embodiment the method also includes a step for the loading the prime stack lane comprising the multiple sub steps of placing a case containing blanks into the prime stack lane and removing the case. In this loading step the case is placed into the prime stack lane such that the blanks are oriented substantially perpendicular to the angularly oriented support plate, such that the blanks, oriented perpendicular to the magazine support plate, are also oriented to align with the substantially perpendicular angle of the flow stack on the angle magazine support plate.

In a significant aspect of the present invention, the method also comprises a step for transitioning the blanks in the flowing stack from the angularly oriented support plate to a horizontal machine feed path through a curved transition section such that the blanks in the flowing stack maintain a lean angle after transitioning onto the horizontal machine feed path.

The inventive method of the present invention further provides for the step of triggering prime stack replacement upon detection of the condition wherein a signal from a sensor detects that there are no blanks in the prime stack lane and that a pusher arm has completed a cycle of pushing blanks from the prime stack lane into the flowing stack lane.

The most preferred embodiment also includes the step of applying pressure to the last blank of the flowing stack to maintain the last blank in the flowing stack at the lean angle.

In the most preferred embodiment of the apparatus of the present invention, an apparatus for loading and continuously replenishing blanks into a packaging machine comprises an angularly inclined support plate having a flowing stack lane area and a prime stack lane area. The apparatus also includes a means for decasing a case of blanks and a means for positioning the blanks in the prime stack lane at a preferred lean angle on the support plate. A means for detecting a low limit of blanks in the flowing stack, along with a means for pushing the blanks from the prime stack lane to the flowing stack lane. A horizontal machine entry means is provided wherein a blank is picked from the flowing stack of blanks for further processing. In a critical feature of the inventive apparatus, the blanks in said flowing stack are oriented at a preferred lean angle. The apparatus of the present invention also comprises a transition section between the angularly inclined support plate section and the horizontal machine entry means, as well as means for triggering replenishment of blanks in the prime stack lane. Further, a flowing stack follower means is provided to maintain pressure on the last blank to maintain the lean angle of the last blank, flat item. In a significant aspect of the present invention, the angularly inclined support plate is adjustable to accommodate different sizes and shapes of blanks. The angular support plate also comprises a low friction surface to allow gravity feed of the flowing stack in the flowing stack lane.

The apparatus of the present invention comprises a prime stack lane that is parallel and next to the flowing stack lane, as well as a transition section between the angularly inclined support plate and the horizontal machine entry means through which a lean angle of the blanks is maintained throughout the flowing stack into the packaging machine. An end follower device provides a means for maintaining the substantially vertical orientation of the last blanks in the flowing stack as the flowing stack becomes depleted until replenishment of the flowing stack with the blanks for the prime stack occurs.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic representation of a robot depalletizer selecting and loading a case from a pallet to the present invention magazine.

FIG. 1A is a detailed schematic representation of a topless case of blanks utilized within the packaging operation.

FIG. 1B is a detail schematic representation of a case being procured by the articulating robot Arm from the pallet.

FIG. 1C is a detailed schematic representation of the upended empty case being removed by the robot after placement of the blanks onto the inclined support plate.

FIG. 1D is a detailed schematic representation of the removal of the case from the blanks on the inclined support plate.

FIG. 1E is a detailed schematic representation of the case being jogged up and down to allow removal without disturbing the front blanks.

FIG. 1F is a detailed schematic view illustrating the use of a vacuum means positioned in the prime stack holding bar to hold the face of the front blanks down during case extraction.

FIG. 1G is a blown up detail illustration of FIG. 1F.

FIG. 1H is a detailed schematic view illustrating the use of a vacuum means positioned under the angled support plate to hold the edge of the front blanks down during case extraction.

FIG. 1J is a blown up detail illustration of FIG. 1H.

FIG. 2 is a representation of the depalletization step in which the robot depalletizer initially secures the case from its position on the pallet.

FIG. 3 is a schematic representation of the step in the depalletization sequence, wherein the robot positions the case of blanks therein into the prime stack lane of the magazine.

FIG. 4 is a schematic representation of the inclined support plate of the present invention with a flowing stack lane and a prime stack lane.

FIG. 5 is a schematic representation of the inclined support plate with the prime stack lane loaded with blanks parallel to the flowing stack lane.

FIG. 6 is a schematic representation of the magazine of the present invention wherein the flowing stack lane is partially depleted as blanks are consumed by the packaging machine.

FIG. 7 is a schematic representation of the step in the sequence of operations of the magazine wherein the flowing stack depletion is detected by a sensor and the prime stack is moved into the flowing stack lane.

FIG. 8 is a schematic representation of the magazine replenishment step wherein the prime stack blanks are pushed into the flowing stack lane.

FIG. 9 is a schematic representation of the step in the magazine replenishment wherein the pusher plate has returned and the prime stack lane is empty awaiting a new supply of blanks.

FIG. 10 is a front sectional view of the flowing stack of the present magazine wherein the benefit of the incline support plate is illustrated.

FIG. 11 is a schematic view of the adjustable incline support plate that provides for altering of angle of inclination to accommodate alternative blanks.

DETAILED DESCRIPTION OF THE INVENTION

A generic packaging machine 10 is illustrated in FIG. 1 that utilizes flat items, such as blanks, cards, sheets or other flat items that are incorporated or constructed into packages, cartons or boxes. To simplify the nomenclature in this application the broad family of flat items utilized in such a packaging machine are referred to as “blanks”, including without limitation cardboard, corrugated board, and paper board that will be bent, folded and glued to create boxes, as well as cards and sheets that are single, relatively thin sheets of paper stock or card stock, laminated or unlaminated and inserted or incorporated into packages, all contemplated within the term “blanks”. As depicted in FIG. 1, a number of cases 16 containing blanks are provided on a pallet 14 and are accessible to a robot depalletizer 12. The cases 16 are shown in FIG. 1A as a horizontal stack of blanks 18 in an open top case 16. An articulating robot arm 20 is equipped with a suction device 21, sandwich top plate 22 and sandwich bottom plate 24. For each case 16 on the pallet 14, the articulating robot arm 20 extends and applies the suction device 21 to the side of the case 16 to pull the case 16 in direction S so that is between the sandwich bottom plate 24 and sandwich top plate 22. The sandwich top plate 22 then applies downward pressure P1 on top of the case and the sandwich bottom plate 24 applies pressure P2 on the bottom of the case 16 (see FIG. 1B) to securely hold the blanks 18 within the case 16, and between the sandwich top plate 22 and the sandwich bottom plate 24. The articulating robot arm 20 then rotates in direction RO as shown in FIG. 2, and from the position adjacent the pallet 14 to a position adjacent the packaging machine 10. During rotation in direction RO the articulating robot arm 20 inverts the case 16 containing the blanks 18, they are positioned just above the inclined support plate 28 with the sandwich top plate 22 on the bottom and the sandwich bottom plate 24 on the top. Once the articulating robot arm 20 has positioned the inverted case 16 and blanks 18 immediately above the angled magazine support plate 28 the pressure of the top plate 24 and bottom plate 22 is released to allow the suction device 21 plunger arm 23 to extend in the direction shown in FIG. 1C to push the blanks 18 and case 16 off of the bottom plate 22 and onto the magazine support plate 28 (see FIG. 1C) allowing the blanks 18 to fall onto the angled magazine support plate 28. The case 16, still retained by suction device 21 between the top plate 22 and bottom plate 24 of the articulating robot arm 20, is then lifted in direction L off the blanks 18 (see FIG. 1C). As a result of the case 16 and blanks 18 being positioned on the angularly inclined support plate 28, the lifting of the case 16 in direction L for removal is not perpendicular to horizontal and may result in a force exerted by the case 16 on the front blanks 18F (FIGS. 1D, 1E) as the case 16 is lifted. Depending on the nature of the blanks 18, whether they are heavy cardboard blanks, or thin, laminated paper sheets, or something in between, the force exerted on the front blanks 18F by the rising case 16 may cause the front blanks 18F to be disadvantageously lifted along with the case 16 see FIGS. 1D and 1E). To address the problem of the front blanks 18F rising with the lifting of the case 16, the outcome of beneficially providing prime stack blanks 18 on the angularly inclined support plate 28 and then lifting the case 16 off of the angularly oriented blanks 18, the preferred embodiment of the present invention comprises alternative means for ensuring that the front blanks 18F are not lifted and removed during extraction of the case 16 to prevent malfunction. In a first embodiment, to prevent malfunction from lifting the blanks 18F, the case 16 is jogged up and down, and partially lifted and lowered as necessary so that any of the blanks 18 F that are initially lifted along with the case 16 are jogged up and down and replaced back down onto the angularly inclined support plate 28 when the case 16 is removed (FIG. 1E). In another preferred embodiment, a vacuum means 54 is provided at the prime stack holding bar 52 on the front face of the front blanks 18F to retain the front blank 18F against the holding bar 52 to prevent it from being lifted off of the angularly inclined support plate 28 while the case 16 is lifted (see FIGS. 1F and 1G). In yet another preferred embodiment, a vacuum means 56 is provided under the angularly inclined support plate 28 (see FIGS. 1H and 1J) to hold the edges of the front blanks 18F down onto the angularly inclined support plate 28 during removal of the case 16. While this structure provides preferred embodiments and methods for removal of the case 16 to load blanks 18 into the magazine and onto the angularly inclined support plate 28, other methods and embodiments are contemplated by the principles of the present invention, and the use of such other embodiment does not depart from the principles of this invention.

The magazine support plate 28 is provided as part of an overall magazine assembly 26 and, in the most preferred embodiment of the mention, the magazine support plate 28 includes a low friction surface 29 that will allow blanks 18 to be moved and slide across the surface 29 with relative ease. The low friction surface 29 allows the blanks 18 to slide down the angled surface 29 driven by gravity only, as depicted in FIGS. 2-8, and urged and fed into the curved transition section 38 as further described herein.

On the angularly inclined magazine support plate 28 there is provided a flowing stack lane area 30 and a prime stack lane area 32. When the robot depalletizer 12 places the upended case 16 and blanks 18 onto the magazine support plate 28, the blanks 18 are positioned in the prime stack lane 32 as shown in FIGS. 2, 3 and 4. The flowing stack lane 30 on the support plate 28 is aligned with the overall flowing stack 31 that extends from the magazine structure 26 all the way to the packaging machine entry pick point 44 at which the blanks 18 enter the packaging machine for further processing, construction or insertion (FIG. 10). As the packaging machine 10 consumes the blanks 18 in the flowing stack 31, it will eventually be necessary to reload an additional supply of blanks 18 into the flowing stack 31. As depicted in FIG. 7, when the flowing stack 31 has been depleted such that sensor 42 detects depletion of blanks 18 from the angularly inclined portion 36 of the flowing stack 31, the substantially horizontal stack of blanks 18 on the angular incline support plate 28 that are in the prime stack lane 32 are pushed across the low friction support plate 28 by pusher arm 34 (see FIGS. 6-8). It should be noted that, in the event that an end follower (not shown) is used to maintain pressure on the back of the flowing stack to ensure that they remain upright, in the event that a follower is applied at the rear of the flowing stack, as discussed above, the follower is disengaged to allow the prime stack blanks to be pushed into the flowing stack and then reengages upon receiving a signal that the prime stacker pusher bar has returned to its position adjacent the prime stack lane.

When the flowing stack 31 has been replenished and the depletion sensor 42 no longer detects depletion, the pusher arm 34 is retracted as shown in FIG. 9 so that the prime stack lane 32 is empty and can be replenished with a new supply of blanks 18 from the pallet 14 (FIGS. 2-5). A prime stack lane empty sensor 35 is provided that detects the absence of blanks 18 in the prime stack lane 32. Another sensor 37 detects the return of the pusher arm 34 after completing its travel back and forth across the support plate 28 to move the blanks 18 into flowing stack 31, as described above, such that the combined detection of the absence of blanks 18 in the prime stack lane 32 and the detected return of the pusher arm 34 results in a permissive signal to be sent to the robot depalletizer 12 to procure a new case 16 to resupply blanks 18 to replenish the prime stack lane 32 of the magazine 26.

In a significant aspect of the present invention, the angle of inclination A of the magazine support plate 28 (see FIGS. 10 and 11) is of critical importance, and the principles of the present invention allow for both coarse and fine adjustment of the angle of inclination (see FIG. 11). As discussed further herein, the composition, size, weight, rigidity and material aspects of the blanks 18 will be determinative of the optimal angle of inclination A. For example, blanks constructed from corrugated cardboard are different from blanks constructed of paperboard which are very different from blanks constructed from glossy paper card inserts. The construction and composition of the blanks 18 is a significant consideration in a number of aspects, affecting how the blanks 18 are handled, and when some additional handling equipment is required for some blanks 18 and not for others, as well as adjustment of the angle of inclination of the inclined support plate 28. In the preferred embodiment of the present invention, for example, an end follower (not shown) is available to maintain the tail end of the flowing stack to keep the last few blanks 18 upright in the flowing stack and to prevent them from falling over as they flow down the gravity fed angularly inclined plate 28. Depending on the particular characteristics of the blanks 18, the angle of inclination may also be adjusted to balance the sliding movement down the inclined path portion of the flowing stack 31, and the advantages and disadvantages of having the inclined flowing stack applying pressure at the entry to the curved transition section 38 (FIG. 10) to facilitate flow through the entire length of the flowing stack 31 while maintaining the desired lean angle B at the entry to the packaging machine. As is known in the prior art, it is advantageous to provide blanks 18 with a forward lean angle B as they approach and enter the low pressure throat 60 at the packaging machine entry (see pick point 44 in FIG. 10) where they reach the picking station at which the packaging machine picks the next blank NB for processing (see FIG. 11). Generally it is desirable for the next blank NB to have a forward lean angle B of between 10 and 25°to vertical (FIG. 10). The purpose of the lean angle for selection of the next blank NB is to facilitate the picking by, for example, accelerating the next blank NB near the bottom, using a driven belt 50 (see FIG. 10) without creating a risk of the next blank NB from falling forward due to too much lean.

To move blanks 18 stably through the flowing stack 31 to arrive at the entry pick point 44 to the packaging machine with an adequate lean angle B, it is necessary to have the entire flowing stack 31 progressing with a lean angle. This is accomplished within the principles of the present invention by initially registering blanks 18 on the angularly inclined support surface 28 at the same angle in both the prime stack lane 32 and the flowing stack lane 32 to allow uninterrupted operation of the packaging machine even during replenishment of the magazine 26 as set forth herein.

In the most preferred embodiment of the present invention, it is contemplated that the inclination angle A of the angularly inclined support plate 28 is balanced between being sufficient to have blanks 18 slide down the low friction surface 29 driven by gravity in a inclined section 36 of the flowing stack 31 (see FIG. 11) while not being too great an angle that complicates the loading of blanks 18 into the prime stack lane 32, with specific consideration given to the angle at which the case 16 is lifted off the blanks 18 (FIGS. 1D and 1E). In addition, the pressure exerted in the flowing stack 31 at the entry to the curved transition section 38 is critical to properly and stably move the blanks 18 through the curved transition section 38 and is a controllable variable based upon the weight and composition of the blanks 18 and the angle of inclination A. It is a countervailing concern to prevent excessive pressure on the rearward blanks 18 at the entry to the curved transition section 38. Thus, within the principles of the present invention the calculation of the angle of inclination must account for loading of blanks 18 into the prime stack lane 32, at angle of inclination A, which will vary depending on the size, structure, composition, and weight of the blanks 18, with other considerations for the angle of inclination A being that it is desirable that the blanks 18 move freely down the low friction surface support plate 28 driven by gravity or, alternatively, an end follower pusher, while providing enough pressure to drive the blanks into the curved transition section 38 without being excessive vertical downward pressure at the entry to the curved transition section 38. It is contemplated within the principles of the present invention that and end follower may be employed in addition to or instead of utilizing gravity as the sole driver of the flowing stack blanks 18 down the inclined angularly inclined support plate 28.

The blanks 18 in the flowing stack 31 travel through the curved transition section 38 and then enter the horizontal section 40 of the flowing stack 31 progressing until reaching the pick point 44 where the next blank NB is selected and proceeds into the packaging machine for further processing (FIG. 10). The bottom of the blanks 18 may be accelerated through the curve transition section 38 such that the desired lean angle B for entry to the packaging machine is maintained. However, since both the angle B and the inclination angle A of the support plate 28 may vary depending on the nature, weight, composition, and parameters of the blanks 18, the necessity and extent of the acceleration through the curved transition section 38 will vary. The angle of inclination A of the support plate 28 will generally be in the range of 30 to 45°. It is critical that for each blank 18 the size, weight, sickness, smoothness, and other parameters will be important considerations to determine the proper angle of inclination A of the support plate 28. As the blanks 18 travel down the support plate 28, they provide pressure on the back of the blanks 18 as they enter the curved transition section 38 to push the flowing stack blanks 18 through the curved transition section 38. The pressure applied from the flowing stack 31 at the entry to the curved transition section 38 is critical to stabilize the flow through the curved transition section 38 so a low pressure detector 46 is located near the entry to the curved transition section 38, downstream in the flowing stack 31 from the flowing stack low limit detector 42 that will be able to interrupt the operation the continuous flow of the flowing stack 31 to prevent malfunction in the curved transition section 38.

The foregoing description of a preferred embodiment of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiment was chosen and described in order to best illustrate the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto