The present invention concerns a device as well as a method for pulling in flat-stock pieces and precisely-aligned feed of flat-stock pieces at a work station of a rotary machine for processing flat-stock pieces. Among the flat-stock pieces handled are, in particular, flat-stock sheets made of cardboard or pulp sheet, and among the rotary machines involved are, in particular, a rotary die cutter which makes folding-box blanks out of the previously mentioned flat-stock sheets for later production of folded boxes, for example folded boxes for medicines. Among the flat-stock pieces, however, other types of sheet or envelope blanks, etc. can also be handled.
With sheet printing machines, it is well-known that they pull in the sheet(s) being printed from a shingle flow. Here a pivoting gripper grabs the forward edge of the sheet to be pulled in and accelerates it to the cycling speed of the rotary sheet printing machine. A sheet pick-up roller which exhibits one or several roller grippers disposed on its circumference takes up the accelerated sheet from the pivoting gripper with the aid of the roller gripper. The sheet picked up is then further fed by the sheet pick-up roller over some angular sector and finally transfers it, precisely aligned and at cycling speed to the gripper of the rotating printing cylinder.
By way of example, within the scope of the rotary manufacture of folded-box blanks made of sheets of cardboard or pulp sheet, it is advantageous—due to their proportionally high bend strength if compared to paper sheet—to feed in the sheets as straight a line as possible to suction belts at least in that area of the rotary machine in which precise alignment is important. No proposals are known to date in prior art for the type and manner of the precisely-aligned pulling in of sheets to a suction belt.
It is hence the task of the present invention to produce a device as well as a method for pulling in flat-stock pieces and for the precisely-aligned feed of flat-stock pieces at a work station of a rotary machine for processing flat-stock pieces, which makes possible the precisely-aligned pulling of pieces of flat stock, particularly sheets, in a rotary-machine suction belt that transports the pieces of flat stock further.
This problem is solved by means of a device and by means of a method with the features of claims 1 and 6. Further embodiments of the present invention result from the subclaims.
According to the invention, it is proposed to provide (the) sheet pick-up roller with several suction holes which can be charged with intake air in a portion of its circumference or its housing surface in the direction of its rotation behind at least one roller gripper. Using these suction holes, the piece of flat stock is held, besides by the roller gripper, at least partially on the circumference of the sheet pick-up roller. A suction conveyor-belt apparatus exhibits at least one suction belt which can be charged with intake air, to which the piece of flat stock is transferred from the sheet pick-up roller according to the invention. At the same time, the opening of the roller gripper and thus the release of the forward edge of the piece of flat stock to be transferred, as well as the intake-air charge of the suction holes provided in the sheet pick-up roller can be controlled such that the piece of flat stock can be transferred from the sheet pick-up roller to the suction belt essentially without slipping.
The suction holes disposed in the sheet pick-up roller, in addition to the roller gripper, guarantee in an advantageous manner secure feed even with variations in the thickness of the flat-stock pieces. This results from the fact that a gripper always has to be installed for a specified thickness of the piece of flat stock. A relatively thin piece of flat stock which falls below the specified thickness hence may not be held sufficiently firmly by the gripper and as a result may not be held without slipping. In this case, the intake air sucked through the suction holes ensures that the relatively thin pieces of flat stock are held firmly and without slipping on the sheet pick-up roller in spite of the reduced action of the gripper. Within the scope of the present invention, looser tolerances can consequently be tolerated with respect to the thickness of the piece of flat stock.
While the suction belt is continuously being charged with intake air, the intake-air charge to the suction holes in the sheet pick-up roller can, on the one hand, be controlled for the sheet pick-up roller to pick up the piece of flat stock from the gripper apparatus and on the other hand to transfer the flat-stock piece from the sheet pick-up roller to the suction belt.
When transferring the flat-stock pieces from the sheet pick-up roller to the suction belt, at the same time as or immediately after the opening of the roller gripper, the suction holes beginning with the suction holes lying next to the roller gripper circumferentially are operated against the direction of rotation of the sheet pick-up roller one after the other at the least without intake air. At the same time, the piece of flat stock is held in a portion increasing in size or area essentially without slipping on the suction belt, and is transported in a portion decreasing in size or area and being still held on the sheet pick-up roller in a guiding manner.
Operating the suction holes without intake air occurs in a known manner with the aid of a control valve, which is disposed on one of the front sides of the sheet pick-up roller. Within the scope of the present invention, it is conceivable not only to cut off the intake-air charge of the suction holes, but to charge them in addition with compressed air against the rotation direction of the sheet pick-up roller one after the other, and in this way to support the detachment process of the flat-stock piece from the surface of the sheet pick-up roller. This optional measure will be grasped from the phrasing “at the least without intake-air” used in the present application.
Preferably, the suction holes are constructed in a known manner in the form of rows of suction holes, each being disposed parallel to the axis of the sheet pick-up roller and comprising a plurality of suction holes. The gradual cut-off of the intake-air charge against the rotation direction of the sheet pick-up roller can occur row-by-row according to the invention, so that the rows of suction holes are operated one after the other without intake air. Alternatively, the possibility exists to combine two or several rows of suction holes adjacent circumferentially to a group of suction holes and the groups of suction holes created thereby operating at the least without intake air individually one after the other.
The control of the intake-air charge of the suction holes occurs with the transfer of the flat-stock piece by the sheet pick-up roller from the gripper apparatus in such a way that the suction holes, beginning with the suction holes lying circumferentially next to the roller gripper, are operated against the rotation direction of the sheet pick-up roller one after the other from the state without intake air to the state of being charged with intake air. Here also as an alternative to row-by-row guidance, two or several rows of circumferentially adjacent suction holes may be combined to a group of suction holes and the suction-hole groups thus created can be operated individually one after the other from the state without intake air to the state of being charged with intake air.
The axis of the sheet pick-up roller is preferably disposed essentially vertically above the axis of the guide pulley to guide the continuously running suction belt. If such an arrangement is chosen, it cannot be avoided that in that area of the suction belt in which the piece of flat stock will be picked up, there is a zone with no suction effect.
Provided this is the case, the roller gripper can then first be opened, if required, when the forward edge which it holds of the flat-stock piece to be transferred is fed by the sheet pick-up roller through the zone with no suction effect.
It is conceivable to arrange the axis of the sheet pick-up roller horizontally offset relatively to the axis of the guide pulley, so that the forward edge of the piece of flat stock to be transferred can be moved tangent to the transport plane of the suction belt in its suction zone. If such a horizontal setting is not possible, then the forward edge of the flat-stock piece can be fed with the closed roller gripper through the zone without suction effect and at the same time be moved a little out of the transport plane of the suction belt or can be lifted up or raised out of it. A positively secured transport transition of the zone of the suction belt without suction effect can be attained in this way, if necessary.
The roller gripper or grippers protrudes or protrude radially from the housing surface of the sheet pick-up roller. In order to make it possible for the transport plane of the suction belt to end up lying tangent to the movement path of the surface area of the sheet pick-up roller that is provided with suction holes, the suction belt exhibits a number of drop spaces corresponding in number to roller grippers into which the respective roller gripper can drop when transferring the piece of flat stock to the suction belt. Either throughholes or, if necessary, just recesses in the suction belt can act as the drop spaces. Alternatively, there is the possibility of providing the suction conveyor-belt apparatus with several suction belts or suction straps running parallel to one another and with spaces in between. The roller gripper or grippers can then drop into each one of the spaces when transferring the flat-stock piece to the suction belts or suction straps.
One embodiment of the present invention is described below by way of example, using the drawings enclosed. They show:
In
The sheet pick-up roller 3 exhibits at its circumference two roller grippers 4 lying one behind the other in
With the aid of the roller gripper 4 as well as of the suction holes 5, the sheet pick-up roller 3 transfers the flat-stock sheets B to the suction conveyor-belt apparatus 6 shown in
In
As is particularly shown in
In
In
The transfer, without slipping and thus precisely aligned, of the flat-stock sheet B to the suction belt 7 can occur in different ways with regard to the zone SZ with no suction effect.
Within the scope of a first method for transferring the sheet of flat stock B to the suction belt 7, the roller grippers 4 of the sheet pick-up roller 3, shown at 6 o'clock in
In the rotation position of the sheet pick-up roller 3 in
A second method for transferring the sheet of flat stock B to the suction belt 7 differs from the first method in that the roller grippers 4 are already open when they are in the 6 o'clock position of
Independent of the manner in which the transfer of the flat-stock sheet B to the suction belt 7 occurs, the area ZB shown in
Provided that the spatial relationships with respect to the movement path of the gripper apparatus 2 permit it, the possibility alternatively exists of setting the sheet pick-up roller 3 in
As may be seen in
Alternatively, the perforated suction belt 7 shown in
A further alternative exists in which the suction conveyor-belt apparatus 6 instead of the suction belt 7 is fitted with four relatively narrow suction belts 12 according to
Number | Date | Country | Kind |
---|---|---|---|
10 2007 035 435 | Jul 2007 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/EP2008/005740 | 7/15/2008 | WO | 00 | 1/28/2010 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2009/015761 | 2/5/2009 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
3791642 | Schunemann | Feb 1974 | A |
5938193 | Bluemle et al. | Aug 1999 | A |
6702283 | Berlingen et al. | Mar 2004 | B2 |
7845636 | Isaak et al. | Dec 2010 | B2 |
20020135123 | Maul et al. | Sep 2002 | A1 |
20040026851 | Schaede et al. | Feb 2004 | A1 |
20040164481 | Edinger | Aug 2004 | A1 |
20050012265 | Berlingen et al. | Jan 2005 | A1 |
20090139838 | Isaak et al. | Jun 2009 | A1 |
Number | Date | Country |
---|---|---|
19 17 795 | Nov 1969 | DE |
24 39 790 | Mar 1976 | DE |
44 39 808 | May 1996 | DE |
202004009490 | Nov 2004 | DE |
10 2004 020 252 | Dec 2004 | DE |
102004058601 | Aug 2005 | DE |
10 2006 015 731 | Oct 2007 | DE |
0 864 520 | Sep 1998 | EP |
1 801 060 | Jun 2007 | EP |
Number | Date | Country | |
---|---|---|---|
20100201060 A1 | Aug 2010 | US |