Automated bundling and stacking of folded corrugated boxes

#The present invention relates to the manufacture of boxes from corrugated stock material. In particular, the invention relates to an automated apparatus and method for counting, squaring, bundling, and stacking loads of folded corrugated blank boxes.

#The present invention relates to manufacturing boxes from corrugated paper stock. As used herein and as well understood in the industry, corrugated stock refers to a paper product that is also commonly (but somewhat erroneously) referred to as "cardboard." More properly, corrugated board is formed from one or more pieces of "fluted" paper, a term that describes paper that has been crimped into a somewhat sinusoidal cross section by an appropriate fluting machine. One or more layers of flat paper typically referred to as "liners" are glued to the fluted layer. Accordingly, many corrugated boxes (as well as corrugated packing inserts and similar structures) are formed of inner and outer liner sheets, with one or more fluting layers in between, and with at least one liner between each fluting layer.

#Because corrugated board is typically formed in long running sheets, it must be cut and folded to form boxes. Typically, the corrugated board (which can be referred to as a "blank") is first cut and creased to define the portions that will eventually be folded. The blank is then partially folded and a glue strip is applied to one side to fasten it to an overlapping side. The resulting structure is a flattened parallelogram of corrugated board containing cuts and creases that will later define the sides and flaps of the box, and thus its eventual solid rectangular shape. The folding and gluing operation is usually automated, and carried out by a machine referred to as a "folder-gluer." A printing step is often carried out on the blanks at some point in this process. Because the present invention does not generally relate to printing boxes, the specific details of printing will not be discussed in any further detail herein. Boxes are, however, typically printed, folded, and glued one at a time. Because corrugated boxes are often used in large volumes, these individual flattened boxes must be collected, counted, bundled, and stacked into loads for eventual shipment to an end user, typically in the flattened condition.

#FIG. 1 is a perspective view of an apparatus according to the present invention;

#FIG. 2 is a perspective view similar to FIG. 1 illustrating a bundle of box blanks in a different position;

#FIG. 3 is a side elevational view taken along elevation line A--A of FIG. 1 and showing the progression of a bundle through the apparatus of the invention;

#The present invention is an apparatus for automated bundling and stacking of corrugated folded and glued boxes and is broadly designated at 20 in FIG. 1. In its overall parameters, the apparatus comprises a squaring station broadly designated at 21 for receiving individual folded (i.e., flat) corrugated boxes and squaring the boxes into a bundle; a conveyer broadly designated by the bracket 22 for advancing a squared bundle B of folded boxes from the squaring station 21; a lift broadly designated at 23 adjacent the conveyer 22 for successively receiving squared bundles B from the conveyer 22; means for delivering a squared bundle from the conveyer 22 to the lift 23 with the lift positioned below the plane of the conveyer 22; and an exit conveyer broadly designated at 24 for discharging a stack of bundles from the lift.

#The operation of the invention of the apparatus described herein is enhanced by a plurality of detectors, preferably photodetectors or proximity detectors, that identify the positions of folded glued boxes, bundles of boxes, and stacks of bundles as they progress through the apparatus. Such detectors are generally well known in the art and will not be otherwise described in detail. An exemplary discussion of photodetectors is, however, set forth in Dorf, The Electrical Engineering Handbook, including Section 31.2 ("Sources and Detectors") at page 811 ff, Sections 56.1 and 56.2 ("Physical Sensors") at page 1255ff, and "Photodiodes and Solar Cells" at page 524. The detectors are also relatively small, particularly when compared to the overall device 20. Thus, in FIG. 1 the photodetectors will be identified by position rather than as discrete illustrated elements. A first detector is positioned at location 25 adjacent the entry portion of the apparatus 20 and counts individual corrugated boxes as they are fed into a bundle at the squaring station 21. A second detector is positioned at location 26 along the conveyer 22 for identifying the presence of a bundle B on the conveyer 22. A third detector is positioned at location 27 the downstream end of the conveyer 22 for identifying the movement of a leading or trailing edge of a bundle B past the third detector. A fourth detector is positioned at location 30 at the upper range of movement of the lift 23 for identifying the movement of the top of a bundle B as the lift 23 lowers. Finally, a fifth detector, whose position at location 31 is at best illustrated in FIG. 9, is positioned adjacent the exit conveyer 24 for identifying the discharge of a stack from the exit conveyer.

#Other elements of the apparatus 20 and the method in which it is used are best understood by a description of the operating sequence which is illustrated by FIGS. 1-10.