PUNCHING OR STAMPING MACHINE AND SHEET PROCESSING METHOD

Abstract

In a sheet processing method for sheets of paper or cardboard, a sheet for processing is, in the processing station, firstly brought to a standstill and then set down, whereas the processed sheet is, in the output station, set down from a moving state. A punching or stamping machine has an input station, a processing station and an output station arranged one behind the other in a sheet transport path, and a sheet gripping device which is designed to set down a sheet for processing in the processing station when the sheet gripping device has come to a standstill in a second reversal position, and to set down a processed sheet in the output station as the sheet gripping device approaches the second reversal position.

Claims

1. A sheet processing method for sheets of paper, cardboard, plastic or the like, in which sheet processing method an input station for the provision of sheets for processing, a processing station for processing a sheet arranged therein, and an output station for the setting-down of processed sheets are provided one behind the other in a sheet transport path, and, repeatedly in series, in the input station, a sheet for processing, and in the processing station, an already-processed sheet, are gripped, the sheet for processing is moved from the input station into the processing station and is set down, and the processed sheet is moved from the processing station into the output station and is set down, and the sheet for processing is processed in the processing station, wherein the sheet for processing is, in the processing station, firstly brought to a standstill and then set down, whereas the processed sheet is, in the output station, set down from a moving state.

2. The sheet processing method as claimed in claim 1, in which, in the output station, a conveyor which operates continuously with a conveying speed is provided for the onward transport of a sheet, onto which conveyor the processed sheet is set down.

3. The sheet processing method as claimed in claim 2, in which the sheet for processing and the processed sheet are moved with a transport speed which, at least during the setting-down of the processed sheet in the output station, at least approximately corresponds to the conveying speed of the conveyor.

4. The sheet processing method as claimed in claim 2, in which the processed sheet is held on the conveyor by generation of an air pressure difference between a top side and a bottom side of the processed sheet.

5. The sheet processing method as claimed in claim 2, in which the processed sheet is held on the conveyor by the generation of at least one force which acts on a top side of the processed sheet.

6. A punching or stamping machine, comprising an input station, a processing station and an output station arranged one behind the other in a sheet transport path, and a sheet transport device which is designed for gripping, moving and setting down two sheets, which sheet transport device has at least one linear guide arranged parallel to the sheet transport path and has a sheet gripping device which is movable back and forth along the linear guide between a first reversal position and a second reversal position, wherein, in the first reversal position, the sheet gripping device is positioned in the input station and in the processing station in order to grip in each case one sheet, and in the second reversal position, the sheet gripping device is positioned in the processing station and in the output station in order to set down in each case one sheet, wherein the sheet gripping device is designed to set down a sheet for processing in the processing station when the sheet gripping device has come to a standstill in the second reversal position, and to set down a processed sheet in the output station as the sheet gripping device approaches the second reversal position.

7. The punching or stamping machine as claimed in claim 6, in which the sheet gripping device has at least two gripping elements which are controllable separately from one another.

8. The punching or stamping machine as claimed in claim 7, in which the sheet gripping device has a common base rail with which the at least two gripping elements interact in order to independently of one another grip in each case one sheet and/or in order to independently of one another set down in each case one sheet.

9. The punching or stamping machine as claimed in claim 6, in which a conveyor which operates continuously with a conveying speed and which serves for the onward transport of a sheet is arranged in the output station.

10. The punching or stamping machine as claimed in claim 6, in which the sheet gripping device moves between the first reversal position and the second reversal position with a transport speed which, at least during the setting down of the processed sheet in the output station, at least approximately corresponds to the conveying speed of the conveyor.

11. The punching or stamping machine as claimed in claim 9, in which the conveyor is designed to generate a negative pressure at the bottom side of the processed sheet.

12. The punching or stamping machine as claimed in claim 11, in which the conveyor is a belt-type conveyor with a perforated belt and with a suction box arranged under said belt.

13. The punching or stamping machine as claimed in claim 9, in which, above the conveyor, there is arranged at least one pressure-exerting means which acts on a top side of the processed sheet.

14. The punching or stamping machine as claimed in claim 6, in which the at least two gripping elements are operatively connected to a jointly acting actuating device for gripping the respective sheet and to separately acting actuating devices for setting down the respective sheet.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The invention will be discussed in more detail below on the basis of an exemplary embodiment and associated drawings, in which FIGS. 1 to 8 show different method steps on a punching or stamping machine.

DETAILED DESCRIPTION

[0031] The punching or stamping machine 1 illustrated in FIGS. 1 to 8 comprises a discontinuously operating input station, a discontinuously operating processing station, and a continuously operating output station. Laterally adjacent to the input station, the processing station and the output station, and thus parallel to a sheet transport path along which sheets are moved through the punching or stamping machine, there extends a sheet transport device which is designed for gripping, moving and releasing two sheets, which sheet transport device has a linear guide arranged parallel to a sheet transport path and has a sheet gripping device, which sheet gripping device is movable back and forth along the linear guide between a first reversal position and a second reversal position and has a common base rail, which in the exemplary embodiment is the lower rail, and two separately activatable gripping elements, which in the exemplary embodiment are partial rails of the upper rail, which gripping elements interact with the common base rail in order to grip in each case one sheet at a lateral edge.

[0032] Laterally adjacent to the punching or stamping machine 1 in the region of the input station 11, there is arranged a sheet stack by means of which the sheets for processing are provided to the machine and fed individually to the input station.

[0033] In FIG. 1, the sheet gripping device is arranged in a first reversal position, in which a first gripping element for gripping a sheet for processing is positioned in the input station and a second gripping element for gripping a processed sheet is positioned in the processing station. Those gripping elements are open and are thus ready to grip a respective sheet.

[0034] FIG. 2 shows how a sheet for processing is removed from the sheet stack and moved transversely with respect to the sheet transport path into the input station, whereas, in the processing station, an already-processed, that is to say stamped or punched, sheet is situated such that it can be gripped by the second gripping element. In FIG. 3, the sheet for processing has also come to a standstill in the input station, such that it can be gripped by the first gripping element.

[0035] FIG. 4 shows how the first gripping element grips the sheet for processing lying in the input station, and the second gripping element grips the processed sheet lying in the processing station. The gripping occurs simultaneously by virtue of both gripping elements being simultaneously closed by means of a common actuating device, such that both sheets are gripped at a lateral edge, that is to say an edge running parallel to the sheet transport path.

[0036] FIG. 5 shows how the sheet gripping device is, with the closed gripping elements and with the two sheets, moved from the first reversal position in the direction of the second reversal position. FIG. 6 illustrates how the second gripping element is opened by means of a separate actuating device and sets down the processed sheet on a continuous conveyor arranged in the output station, which conveyor moves at the same speed as the sheet gripping device as the sheet gripping device approaches the second reversal position, that is to say already before the second reversal position is reached. From this point in time onward, only the sheet for processing is moved by the first gripping element of the sheet gripping device, whereas the processed sheet is moved onward by the continuous conveyor.

[0037] FIG. 7 shows the moment at which the sheet gripping device reaches the second reversal position and comes to a standstill there. The first gripping element sets down the sheet for processing in the processing station by virtue of the first gripping element being opened by means of a separate actuating device. Both gripping elements are now open, and the processed sheet is moved onward by the continuous conveyor arranged in the output station.

[0038] As shown in FIG. 8, the processed sheet exits the punching or stamping machine 1 on the conveyor, for example in order to be fed to a breakaway station, while the sheet gripping device with the two gripping elements is moved back into the first reversal position and the sheet for processing is processed, that is to say punched or stamped, in the processing station. The described steps are subsequently repeated again.