The present disclosure is directed to a conveyor having opposed upper and lower decks for transporting a stream of sheets, and, more specifically, toward a conveyor having opposed upper and lower conveyor decks, one of which includes a plurality of belts for contacting the sheets and one of which includes a plurality of wheels for contacting the sheets.
A conventional stacking apparatus 10 is illustrated in
Die cut machines produce a certain amount of scrap material during operation which consists mainly of the portions of the input material that do not become part of a finished blank. In addition, each blank may include slots or through-openings. The material cut from the blanks to form these slots and through-openings also constitutes scrap.
Most scrap material produced by the die cut machine drops beneath or immediately in front of the die cut machine as it operates. However, it is not uncommon for a material sheet to be cut incompletely so that portions of the sheet that were supposed to be removed wind up traveling into the layboy with the blank. Excessive scrap in the transport path between the layboy section and the final stack of blanks may adversely affect the transport of the blanks. That is, the scrap may interfere with the alignment of the blanks or lead to jams. Alternately, if the scrap is carried all the way through the stacker and into the final stack of blanks, the blanks in the stack will have gaps therebetween where the scrap material is present thus resulting in a crooked, or oversized or non-uniform stack of blanks. Some scrap may even end up inside a finished box formed from the cut blanks; this is generally undesirable to most end customers and must be completely avoided in some applications, such as boxes for use to package food.
It is therefore known to provide various scrap removal devices in a layboy. These may comprise, for example, brushes that gently contact a top and/or bottom surface of the moving blanks to dislodge the scrap. It would be desirable to further reduce the presence of scrap in a stream of sheets being conveyed in a sheet stacking system.
It may sometimes be desirable to add an additional conveyor section to a stacking system, between the layboy section 14 and the transfer conveyor 16 or between the transfer conveyor 16 and the main conveyor 18, for example. This additional section may be, for example, a section configured to divert selected sheets from a stream of sheets as described in co-pending application Ser. No. 15/783,630, filed concurrently herewith, entitled “Diverter Conveyor,” which application is hereby incorporated by reference, or a section having brushes or a fan for removing scrap and dust from the stream of sheets as described in co-pending application Ser. No. 15/783,679, filed concurrently herewith, entitled “Conveyor Section Having A Fan For Dust Removal,” and assigned to the assignee of the present application, which application is hereby incorporated by reference.
Conveyors having upper and lower decks that face each other and define between them a transport path for a single stream of sheets or multiple parallel streams of sheets are known. These conveyors either have belts on the upper deck and belts on the lower deck, which belts have contact surfaces that define the transport path, or have wheels on the upper and lower decks, which wheels define the transport paths. However, in some applications, such as those discussed herein, it may be advantageous to provide one of the opposed upper and lower conveyor decks with belts and the other with wheels.
Conveyor types are described herein on the basis of the structure that makes contact with a sheet of material being transported along a transport path and that defines one side of the transport path. Therefore, even though the belts of a conveyor having belts are supported by pulleys, which may be considered a type of wheel, a conveyor having belts is not a conveyor in which the wheels are intended to contact the sheets being transported. Conveyor decks discussed herein that have wheels for forming a contact surface for transporting sheets are not conveyors having belts. This is true even if a small portion of one or more of the pulleys that support the belts make contact with the sheets being transported.
A first aspect of the present disclosure therefore comprises a conveyor configured to transport sheets along a transport path from an input end to a discharge end. The conveyor includes a first conveyor deck comprising a first plurality of contact elements, each contact element of the first plurality of contact elements having a contact surface movable around a first closed path from a first contact region to a first non-contact region, the first contact regions lying in a first plane or being bounded by the first plane. The conveyor also includes a second conveyor deck comprising a second plurality of contact elements, each contact element of the second plurality of contact elements having a contact surface movable around a second closed path from a second contact region to a second non-contact region, the second contact regions lying in a second plane or being bounded by the second plane. The transport path of the conveyor is defined by the contact surfaces of the first plurality of contact elements in the first contact region and the contact surfaces of the second plurality of contact elements in the second contact region, and the conveyor is configured such that the sheets make direct contact with the contact surfaces of the first plurality of contact elements and make direct contact with the contact surfaces of the second plurality of contact elements when the sheets move along the transport path. The first plurality of contact elements are belts and the second plurality of contact elements are wheels.
Referring now to the drawings, wherein the showings are for the purpose of illustrating embodiments of the disclosure only and not for the purpose of limiting same,
In
Each of the support shafts 74 includes a plurality of wheels 84. The wheels 84 are fixed against rotation relative to the support shafts 74 and therefore rotate with the support shafts 74. The wheels 84 may be discrete elements that are selectably securable to the support shafts 74, using screws or clamps (not illustrated) so that the number and location of the wheels 84 on the shafts 74 can be adjusted. Alternately, the wheels 64 may be integrally formed with the shafts 74 and thus comprise portions of the shafts 74 that have greater diameters. In other words, each shaft 74 may comprise first portions having a small diameter and second portions having a large diameter, the large diameter portions forming the wheels 84.
The wheels 84 on each of the shafts 74 are evenly spaced in a transverse (third) direction, that is, a direction transverse to the sheet travel direction. However, counting the shafts from front to back in the view of
The wheels 84 are intended to make contact with sheets being transported, and the wheels 84 may therefore sometimes be referred to as “contact elements.” The radially outer surfaces of the wheels 84 may be referred to as “contact surfaces” because they are intended to directly contact sheets being transported through the conveyor section 50. These outer surfaces may be knurled to increase friction between the wheels 84 and the sheets. The portions of the wheels 84 facing in the direction of the upper conveyor deck 56, which portions will directly contact sheets, are described as being located in “contact regions.” These contract regions of the wheels 84 are the regions of essentially line-contact between the sheets and the wheels 84 (because the sheets are not perfectly rigid, the area of contact is likely to be a small angular portion of the wheels 84 rather than a line). The contact regions therefore lie in a plane or are bounded by a plane, the plane representing the plane of a hypothetical perfectly rigid sheet resting on the surfaces of the wheels 84. Therefore, as the wheels 84 rotate, a given point on the surface of each wheel 84 will rotate into and out of the contact region.
Referring now to
A plurality of pulleys 98 are mounted on the middle transverse shaft 88 and attached to the middle shaft 88 so that they rotate with the shaft when the shaft 88 is driven. The pulleys 98 are evenly spaced along the middle shaft 88 and may be described as being located at numbered locations 1, 2, 3 . . . 31 along the middle shaft 88. The front shaft 86 also includes a plurality of pulleys 98 that are fixed to the front shaft 86 for rotation therewith. The number of pulleys 98 on the front shaft 86 is approximately one half the number of the pulleys 98 on the middle shaft 88, and the pulleys 98 on the front shaft 86 are aligned with every other one of the pulleys 98 on the middle shaft 88. In
The belts 100 of the upper conveyor deck 56 are examples of sheet contact elements that are configured to make direct contact with sheets traversing the conveyor section 50. The portions of the belts 100 that face the lower conveyor deck 62 form sheet contact surfaces. These sheet contact surfaces lie substantially in a plane parallel to the sheet transport direction. The portions of the belts 100 that face the lower conveyor deck 62 are located in a contact region, and all points on the belts 100 travel from contact regions (facing the lower conveyor deck 62) to non-contact regions (facing away from the lower conveyor deck 62) as the belts 100 rotate.
In operation, the upper conveyor deck 62 is positioned relative to the lower conveyor deck 56 so that the vertical separation between the plane in which the tops of the wheels 84 lie and the plane in which the bottoms of the belts 100 lie are separated by a desired distance based on the thickness of the sheets to be transported. In order to allow adequate control of the movement of the sheets without crushing or damaging the sheets during transport, the vertical separation will be approximately equal to the thickness of the sheets being transported. The sheets will exit the layboy conveyor 68 and enter a nip at the upstream end 70 of the conveyor section 50, which nip is defined by the belts 100 of the upper conveyor section 56 and the wheels 84 of the lower conveyor section 62. The lower conveyor deck drive 81 and the upper conveyor deck drive 96 are coordinated so that the belts 100 travel at the same speed as the tops of the wheels 84, and this pulls the sheets along the conveyor section 50 from the upstream end 70 to the downstream end 72 and ejects the sheets to a downstream conveyor (not illustrated) which may comprise the main conveyor 18 of a stacking system as illustrated in
In many cases, belts provide a greater degree of control over the movement of sheets in a conveyor because a relatively large surface area of the belts remains in contact with the sheets as they move along a conveyor section. At the same time, this greater area of contact may hold scrap against the sheets and prevent the scrap from being removed from the sheets before they are stacked. The inventors have found that using wheels 84 on the lower conveyor deck 62 makes it easier for scrap to fall from the sheets and out of the sheet transport path (onto the scrap removal conveyors 64, for example) than if belts were used on both the upper and lower conveyor decks. That is, all lower surfaces of the sheets are free from roller or wheel contact at some time as the sheets traverse the conveyor section 50. At the same time, the use of belts 100 on the upper conveyor deck 56 provides adequate control over the movement of the sheets. And, because the belts 100 are staggered such that no individual belt 100 extends all the way from the upstream end 70 to the downstream end 72 of the conveyor section 50, all upper surfaces of the sheets are free from belt contact at some point as they traverse the conveyor section 50. This arrangement, when used with brushes, blowers, vacuums or other devices for removing scrap from sheets, has been found to improve the scrap removal process.
The present invention has been described herein in terms of a preferred embodiment. Additions and modifications to this embodiment will become apparent to persons of ordinary skill in the art upon a reading of the foregoing description. It is intended that all such modifications and additions form a part of the present invention to the extent they fall within the scope of the several claims appended hereto.
The present application claims the benefit of U.S. Provisional Patent Application No. 62/408,633 filed Oct. 14, 2016, the contents of which are hereby incorporated by reference.
Number | Name | Date | Kind |
---|---|---|---|
5163672 | Mennie | Nov 1992 | A |
5244197 | Helmstadter | Sep 1993 | A |
5685539 | Janatka | Nov 1997 | A |
5697880 | Auerbach | Dec 1997 | A |
Number | Date | Country | |
---|---|---|---|
20180105381 A1 | Apr 2018 | US |
Number | Date | Country | |
---|---|---|---|
62408633 | Oct 2016 | US |