Folded and glued paperboard “lockbottom” or “autobottom” cartons (also know by other names, including “folded-bottom boxes”) are generally flat as produced, but are characterized by having one edge portion that is much thicker than the opposite edge portion. The thicker edge portion (which normally forms the bottom part of the carton, when erected) consists of multiple plies (typically five) of the construction material, whereas the thinner edge portion (which normally comprises the cover) is typically of only one- or two-ply thickness. When a number of such cartons are stacked together with the same orientation, the resulting batch is of wedge-like form.
To accommodate that characteristic, lockbottom cartons are conventionally loaded into shipping cases as alternating batches of a multiplicity of cartons, arranged in opposite directions with the thicker end of one batch mated with, or complementary to, the thinner end of the adjacent batch. Doing so serves of course to most efficiently utilize the capacity of the shipping case while, at the same time, affording uniform weight distribution.
The systems for handling and loading such collapsed cartons are usually operatively connected directly to the machines by which they are folded and glued, from which they are presented as a shingled stream in which the thicker end portion of each carton is disposed as the leading edge with respect to the machine travel direction. As a practical matter, therefore, the packaging machines are also designed to handle cartons so oriented.
By way of further description, packaging of batches of lockbottom cartons, in an alternating arrangement, is depicted in
Machines for automatically transferring continuously arriving “folded-bottom boxes,” to enable packaging as alternating batches in shipping cases, have previously been provided. One such machine is described in Bensberg et al. U.S. Pat. No. 5,078,260, and is depicted in
That deficiency is indeed discussed in the passage beginning at line 16 in column 4 of the patent: “Since the alternating lay-off from the two conveyor mechanisms 3 and 4 makes its impossible to guide folded-bottom boxes 16, which have a tendency to hook onto one another, over the total lay-off area 11, the boxes are maintained at an angle to the direction of travel as they leave conveyor mechanisms 3 and 4 by rods 14.1 and 14.2 or 15.” Although the rods provided do assist in reducing the “tendency to hook onto one another,” they do not adequately solve the problem.
The reason why hooking (or catching, or interlocking) of cartons occurs during such automatic “overstocking” is illustrated in
Accordingly, it is a broad object of the present invention to provide a transporting system, in a packaging machine, for automatically merging and accumulating substantially identical, but oppositely directed, generally flat articles (especially collapsed folded cartons) in such manner that a leading edge portion of an added article does not catch upon intermediate transverse edge structure present on an underlying article.
A more specific object of the invention is to provide such a transporting system in which conveying means functions to invert articles transported thereby so that they all arrive at a common accumulation location with a substantially continuous side of each article facing upwardly.
Another broad object of the invention is to provide a method for automatically merging and accumulating articles, of the construction described, whereby alternating groups of the articles are delivered to an accumulation location inverted end-to-end but with a substantially continuous side of each article facing upwardly.
As used herein, the word “article” refers to any object that is generally flat and that has the end portion and intermediate edge structure characteristics broadly described. An “article” will usually take the form of a lockbottom carton or the like, but other such objects (e.g., packages having receptacle components attached near one end of a backing board) are also contemplated. An assemblage of a plurality of articles having the same orientation (from side-to-side and from end-to-end) is referred to herein as a “batch,” whereas the term “group” more broadly refers to a plurality of articles having such orientation but arranged either as a batch or as a consecutive sequence of individual articles.
It has now been found that certain of the foregoing and related objects of the invention are attained by the provision of a transporting system, for use in a packaging machine, for automatically merging and accumulating substantially identical, generally flat articles of the kind described, comprising first and second conveying means constructed for transporting the articles along separate paths from a common entrance location of the machine, at which all of the articles have the same, upwardly facing orientation, to a common accumulation location, the conveying means being so constructed as to maintain the articles transported with their endwise axes in alignment with the axis of travel. The first conveying means is so constructed and arranged as to deliver the articles to the accumulation location with the original orientation, whereas the second conveying means is so constructed and arranged as to deliver the articles to the accumulation location with an orientation in which they are inverted from the original orientation, end-to-end about transverse axes thereof, the first and second conveying means delivering the articles transported thereby to generally opposite sides of an upwardly facing support surface present at the accumulation location, for merging and accumulation, usually as a shingled stream. The machine also has diverting means at the entrance location, for presenting equal numbers of articles, as groups, alternatingly to the first and second conveying means for transport thereby. The second conveying means includes a portion that is so constructed as to invert the transported articles, from one side to the other about their endwise axes, so that, at the accumulation location, the substantially continuous sides of the articles face upwardly.
The inverting portion of the second conveying means is constructed to twist through an effective angle of substantially 180° about the axis of travel. The second conveying means may include at least three cooperating, separate sections, with the portion for inverting the articles comprising a section that is interposed between two others. The inverting section will preferably comprise at least one belt, assembled with support means that disposes two portions of the belt closely adjacent to one another for capturing the articles therebetween and for together traversing the two other sections; the inverting conveyor section will desirably comprise a single, endless belt.
In most instances the first conveying means will follow a path that has a substantial portion disposed above the level of the entrance location and the accumulation location (both elevated, but not necessarily at the same height) and the second conveying means will follow a path that has a substantial portion disposed therebelow. The travel axes of the first and second conveying means will normally be disposed substantially on a common vertical plane.
The machine will usually also include third conveying means disposed at the article-accumulation location and having a travel axis with a horizontal portion that extends substantially normal to the above-mentioned common vertical plane. The third conveying means will preferably provide the upwardly facing support surface on which the delivered articles are accumulated such that, with all of the conveying means in operation in appropriately timed relationships, the articles accumulate as a shingled stream, of alternating batches, on the support surface (generally, a belt or apron).
The terminal ends of the first and second conveying means will normally exit at the accumulation location at a level somewhat above the support surface, so that, upon exiting from the conveying means, the articles drop upon the support surface. The exits, or outlets, of the conveying means will usually also be so disposed that, as delivered, the leading end portions of the transported articles extend beyond lateral margins of the support surface, and over the proximal end portions of previously deposited articles, before they are released.
In certain preferred embodiments, the machine will additionally include a hold-down mechanism comprised of at least first and second contact members disposed, respectively, adjacent the generally opposite sides of the support surface at the common accumulation location. Broadly described, the hold-down mechanism will be constructed for moving the contact members, in alternating sequence, between a position proximate the support surface, for bearing upon the end portion of a deposited article, and a position displaced from the support surface for permitting the articles transported by presently discharging conveying means to exit therefrom, unimpeded. More specifically, each of the contact members will desirably comprise at least one brush, typically mounted for pivotal movement between the proximate and displaced positions. Depending upon the configuration of the article being packaged, it may for example be most advantageous to employ two wide brushes as contact members, mounted side-by-side in a laterally tandem relationship along each margin of the article-support surface.
Other objects of the invention are attained by the provision of a method for automatically merging and accumulating (usually as a shingled stream) substantially identical, generally flat articles of the nature described. The method broadly comprises the steps:
providing a multiplicity of articles at a common entrance location, all of the articles having the same, first orientation, taken end-to-end and also side-to-side, with a substantially continuous side facing generally upwardly;
delivering, by first conveying means, first groups of a plurality of the articles to one lateral side of an upwardly facing support surface, at a common accumulation location, with the articles having the first orientation;
delivering, by second conveying means, second groups of an equal number plurality of the articles to a generally opposite lateral side of the upwardly facing support surface at the accumulation location, with the articles having a second orientation in which they are reversed from the original orientation only end-to-end about their transverse axes and not reversed side-to-side about endwise axes thereof, deliveries of the groups of articles being so timed that a first group of the articles alternates with a second group, and that batches of articles merge and accumulate, usually as a shingled stream, so that, at the accumulation location, the discontinuous sides of all of the articles face the upwardly facing support surface and the substantially continuous sides face upwardly.
In most instances, the method of the invention will include a step of inverting the articles of the second groups, by use of the second conveying means, from one side to the other about endwise axes thereof. The articles employed in the method will usually be in the form of collapsed lockbottom folded cartons, or the like, in which the transversely extending thicker end portion is of multiply construction and constitutes the leading edge as the cartons are transported by the conveying means. The opposite, transversely extending thinner end portion (the trailing edge) will usually be of single-ply construction, or occasionally of double-play construction, and the leading edge:trailing edge thickness ratio will typically be 5:1 or 5:2, respectively.
By way of further, more detailed description, after exiting from a machine on which carton blanks are folded and glued, they arrive at the entrance to the transporting system as a shingled stream in which the cartons are overlapped with one another by a value that is typically about ten percent of their running-direction length; this is shown in
With equal spacing between them, a preselected, variable number of individual cartons, constituting a group, are transported in the “x-axis up” direction. Immediately thereafter, an equal-number group of equally spaced individual cartons are transported in the “x-axis down” direction; subsequent groups are established and transported, in the same alternating manner.
The individual cartons arrive consecutively at a merge point at the terminal, exit ends of the two conveyors, at which is provided a third conveyor that runs perpendicular to the x-axis plane (as is also more fully discussed below). That y-axis conveyor operates at a controlled, variable speed and at a selected ratio to the x-axis conveyors (always more slowly); it serves for off-loading of the shingled stream of cartons, generally for deposit into a transport container (for which purpose the conveyor may have a z-axis portion as well).
As seen in
Each of the individual cartons transported in the “x-axis down” direction (depicted in
Turning initially to
Conveyor mechanisms 3 and 4 extend vertically and terminate on each side of and slightly above a horizontal conveyor belt 6 that branches off at approximately the same level as incoming conveyor belt 1 and leads to an unillustrated packing machine. Lower conveyor mechanism 4 extends below conveyor belt 6, through a 180° curve, and back to just above the belt. Upper conveyor mechanism 3 extends, without rotating the boxes, straight to transverse conveyor belt 6 and terminates on the other side of the belt at approximately the same level as lower conveyor mechanism 4. To ensure that both conveyor mechanisms 3 and 4 will convey the boxes to the same extent, conveyor mechanism 3 has a compensation loop. Transverse conveyor belt 6, which is a revolving-belt conveyor, leads to an unillustrated machine that packs the boxes in shipping cartons.
Another embodiment employs, instead of rods 14 and 15, vertical guide rollers on each side of outlet-end pulleys 7 and 8 to force the lateral edges of the boxes up. The circumference of the guide rollers extends to slightly above the lower strand of upper belt 9.1 and 10.1. This relationship can be attained for example by guide rollers with a slightly longer diameter positioned coaxially with outlet-end pulleys 7.1 and 8.1.
Operation of the Bensberg et al. machine is described, at line 63 of column 3 through line 31 of column 4 of the patent, as follows: Incoming conveyor belt 1 constantly supplies an overlapping stream of boxes to transfer device 2 from the assembly and pressure-application mechanism of a folded-bottom box gluer. The folded bottoms of boxes 16 are downstream and their tops upstream and up. A specific number (e.g. ten) of folding boxes 16 are obtained from the overlapping stream backed up upstream of transfer device 2 and supplied individually and following one another separated to one of the two conveyor mechanisms 3 and 4 by distributing baffle 5. Once the prescribed number has been supplied, distributing baffle 5 shifts to the other conveyor mechanism 4 or 3. The result is a continuous overlapping stream on transverse conveyor belt 6. This stream is automatically packed in shipping cartons by an unillustrated packing machine.
The Bensberg disclosure goes on to explain that, since the folding boxes 16 laid off on transverse conveyor belt 6 by lower conveyor mechanism 4 are rotated 180°, in relation to the boxes supplied by conveyor mechanism 3, the boxes are always laid off with their thicker end, constituted by the bottom of the box, on different sides of transverse conveyor belt 6. Since the alternating lay-off from the two conveyor mechanisms 3 and 4 makes it impossible to guide folded-bottom boxes 16, which have a tendency to hook onto one another, over the total lay-off area 11, the boxes are maintained at an angle to the direction of travel as they leave conveyor mechanisms 3 and 4 by rods 14.1 and 14.2 or 15. The angle to the direction of travel stabilizes the boxes to the extent that they can be continuously laid off one on top of another with no problems. Stabilization is in particular necessary for the folding-bottom boxes 16 supplied by lower conveyor mechanism 4, which are finally secured only at the top as they leave belts 10.1 and 10.2 and must be supplied with an additional impetus by the upper sides of the boxes downstream of them.
Turning now in detail to
The illustrated system includes an infeed conveyor section, generally designated by the numeral 30 and providing an entrance support area 32, and an upper conveyor mechanism generally designated by the numeral 34. The infeed conveyor section 32 effectively constitutes part of the lower conveyor mechanism, which additionally includes an inverting section, generally designated by the numeral 36, and a curved delivery section, generally designated by the numeral 38. Albeit important that the articles be adequately captured for reliable transport, it will be appreciated that the conveyors employed in the system can take any suitable form, as will be evident to those skilled in the art. Thus, sets of belts, such as belts 21, 23, 27, 29, 31 shown in
As can be seen, both the upper conveyor mechanism 34 and the delivery section 38 of the lower conveyor mechanism lead to a merge and accumulation location, at which is provided a transverse outfeed conveyor 6 that provides a normally horizontal, belt or apron accumulation surface 40. It will be appreciated that both the upper and lower conveyor mechanisms have travel directions that lie generally on a common vertical plane (i.e., the plane of the page on which
As can be seen in
The feature of the conveyor means, here taking the form of belt 42, that is essential to the invention resides in the twist area 46 at which the contiguous portions 42a, 42b of the belt act together to effectively turn through an angle of 180° (which may involve, for example, a number of 90° or 180° twists, formed prior to joining the opposite ends of a single strand), in traversing the space between the sections 30 and 38, taken with respect to the travel direction axis of the conveyor; the arrows along the span depict the belt crossover and crossback points. In this manner the articles (not shown in
It will be appreciated that, in the prior art system, the lower conveyor mechanism reorients the cartons by effectively inverting them simultaneously both end-to-end (i.e., by making the leading end portion the trailing end portion) and also side-to-side (i.e., by turning them over). The twist of the belt portions 42a and 42b of the illustrated embodiment of the present system effectively reinverts the cartons about their endwise axes to product the final orientation desired; i.e., with the groups alternating and with the continuous sides of all of the cartons facing upwardly at the accumulation location.
These relationships are diagrammatically illustrated in
Turning finally to
Thus, it can be seen that the present invention provides a system for automatically merging and accumulating a multiplicity of substantially identical, generally flat articles (especially folded cartons) as oppositely directed batches and in such manner that a leading edge portion of an article, added to a preexisting shingled stream (or on top of a single previously deposited article), does not catch upon an exposed intermediate edge portion of an underlying article. More particularly, the invention provides a trans-porting system wherein conveying means provided functions to invert articles transported thereby so that all of the articles arrive at the common accumulation area of the machine with the substantially continuous sides of the articles facing upwardly. The invention also provides a method for automatically merging and accumulating a multiplicity of articles of the construction described, whereby the articles are delivered to an accumulation location with an optimal orientation.