Apparatus for separating sheet material

Abstract

A device and a method for separating sheet material is provided. The separation of sheet material is not effected statically, but a suitable pick-up position and/or a suitable pick-up mechanism is selected for each sheet material piece, for example in dependence on the quality of a surface of the sheet material piece to be picked up, in order to pick up the sheet material piece from the sheet material stack and remove it from the same.

Claims

1. A device for separating sheet material, comprising: a sheet material pick-up which is configured to pick up a single sheet material piece from a sheet material stack, which includes several sheet material pieces; and an actuator which is configured to shift the sheet material pick-up, wherein, the device is configured to selectively pick up the single sheet material piece by a first pick-up mechanism of the sheet material pick-up and/or by a second pick-up mechanism of the sheet material pick-up, in order to remove the single sheet material piece from the sheet material stack, and, wherein, the first pick-up mechanism of the sheet material pick-up and the second pick-up mechanism of the sheet material pick-up are of different type mechanisms.

2. The device according to claim 1, further comprising: an image acquisition unit which is configured to capture an image of a surface of the single sheet material piece and to provide image data; and an evaluation unit downstream of the image acquisition unit, which is configured to receive the image data and to provide an evaluation result in dependence on an evaluation of the image data; wherein, the device is configured to select the first and/or the second pick-up mechanism in dependence on the evaluation result.

3. The device according to claim 1, wherein the sheet material pick-up comprises the first pick-up mechanism, which is configured to pick up the sheet material piece by generating a first force of attraction that is a suction force.

4. The device according to claim 3, wherein the sheet material pick-up comprises the second pick-up mechanism, which is configured to pick up the sheet material piece by generating a second force of attraction that is a van der Waals force.

5. The device according to claim 3, wherein the first pick-up mechanism comprises a suction sleeve and a suction piston movably arranged in the suction sleeve, wherein the suction piston is configured to generate a negative pressure by its movement in an empty space of the suction sleeve defined by the suction sleeve and the surface of the single sheet material piece.

6. The device according to claim 5, wherein the suction sleeve is coupled to a guide element of the actuator via a coupling piece.

7. The device according to claim 5, wherein the second pick-up mechanism comprises an adhesive film which is designed to form a van der Waals force upon contact with the surface of the single sheet material piece and wherein the adhesive film is arranged on at least one of an end face of the suction piston and an end face of the suction sleeve.

8. The device according to claim 1, wherein the second pick-up mechanism is configured to pick up the sheet material piece by generating a second force of attraction that is a van der Waals force.

9. The device according to claim 8, wherein the second pick-up mechanism comprises an adhesive film which is designed to form a van der Waals force upon contact with the surface of the single sheet material piece.

10. The device according to claim 1, wherein the actuator is configured to put the sheet material pick-up into a translational movement along a first direction substantially vertical to a perpendicular direction, in order to position the sheet material pick-up at the single sheet material piece and/or in order to remove the single sheet material piece picked up from the sheet material stack, wherein the first direction is substantially vertical to a long side of the single sheet material piece.

11. The device according to claim 10, wherein the actuator is configured to put the sheet material pick-up into a translational movement along a second direction substantially vertical to the perpendicular direction, in order to position the sheet material pick-up at the single sheet material piece and/or in order to remove the single sheet material piece picked up from the sheet material stack, wherein the second direction is substantially parallel to a long side of the single sheet material piece.

12. The device according to claim 1, wherein the actuator is configured to put the sheet material pick-up into a translational movement along a perpendicular direction, in order to perform at least one of positioning the sheet material pick-up at the single sheet material piece and removing the single sheet material piece picked up from the sheet material stack.

13. A method for separating sheet material by a sheet material pick-up which is configured to pick up a single sheet material piece from a sheet material stack, which includes several sheet material pieces, and an actuator which is configured to shift the sheet material pick-up, the method comprising: selectively picking up the single sheet material piece by a first pick-up mechanism of the sheet material pick-up and/or by a second pick-up mechanism of the sheet material pick-up, in order to remove the single sheet material piece from the sheet material stack, wherein, the first pick-up mechanism of the sheet material pick-up and the second pick-up mechanism of the sheet material pick-up are of different type mechanisms.

14. The method according to claim 13, further comprising: shifting the sheet material pick-up using the actuator.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The idea underlying the invention will be explained in detail below with reference to the exemplary embodiments illustrated in the Figures.

(2) FIG. 1 shows a schematic cross-sectional view of an exemplary embodiment of a device for separating sheet material.

(3) FIG. 2 shows a perspective and schematic view of an exemplary sheet material pick-up.

(4) FIG. 3 shows a schematic cross-sectional view of the sheet material pick-up shown in FIG. 2.

(5) FIG. 4 shows a schematic view of an exemplary sheet material piece.

(6) FIG. 5 shows a schematic representation of adhesion properties of the sheet material piece shown in FIG. 4.

DETAILED DESCRIPTION

(7) FIG. 1 shows a schematic cross-sectional view of an exemplary embodiment of a device 1 for separating sheet material. FIG. 1 shows the device 1 merely schematically, in order to explain the function of the device 1. The arrangement of the individual components of the device 1, as they are shown in FIG. 1, hence not necessarily is to be understood as specification for a practical implementation.

(8) The device 1 for separating sheet material includes a sheet material pick-up 12 which is configured to pick up a single sheet material piece 5-1 from a sheet material stack 5. The sheet material stack 5 comprises several sheet material pieces 5-1 to 5-n. In the illustrated exemplary embodiment, the single sheet material pieces 5-1 to 5-n are layered one above the other along a perpendicular direction y. The single sheet material pieces 5-1 to 5-n can, however, also be present in the form of a substantially unordered accumulation. The sheet material stack 5 is located on a sheet material support 3.

(9) For shifting the sheet material pick-up 12 an actuator 11 is provided, which on a base 111 is coupled via a first coupling element 112-1 and a second coupling element 112-2. The actuator 11 in addition includes a guide element 113 which is connected with the sheet material pick-up 12. Via the guide element 113, the sheet material pick-up 12 is shifted along the perpendicular direction y. For example, the actuator 11 places the sheet material pick-up 12 on a surface 51 of the uppermost sheet material piece 5-1 without exerting a pressing force, in order to pick up the uppermost sheet material piece 5-1 from the sheet material stack 5. Furthermore, the actuator 11 can put the sheet material pick-up 12 into a translational movement along a first direction x substantially vertical to the perpendicular direction y, in order to position the sheet material pick-up 12 at the sheet material stack 5 and/or in order to remove a single sheet material piece picked up from the sheet material stack 5. In the illustrated example, the first direction x is substantially vertical to a long side L (cf. FIG. 2) of the single sheet material piece 5-1. In addition, the actuator 11 can put the sheet material pick-up 12 into a translational movement along a second direction z substantially vertical to the perpendicular direction y, again in order to position the sheet material pick-up 12 at the sheet material stack 5 and/or in order to remove a single sheet material piece picked up from the sheet material stack 5, wherein the second direction is substantially parallel to the long side L of the single sheet material piece 5-1.

(10) As a result, the sheet material pick-up 12 of the device 1 is movably mounted along the three directions x, y and z, in order to on the one hand be positioned at the sheet material stack 5 and on the other hand remove a sheet material piece picked up from the sheet material stack 5. For shifting the sheet material pick-up 12, the device 1 can comprise corresponding linear motors (not shown in FIG. 1). Alternatively and/or in addition, the sheet material pick-up 12 can movably be mounted also in directions other than the directions x, y and z. For example, the sheet material pick-up 12 also is movably mounted along one or more directions of rotation, in order to be positioned at the sheet material stack 5 and/or to be shifted, in order to remove a sheet material piece picked up from the sheet material stack 5.

(11) To support shifting and/or positioning of the sheet material pick-up 12 by means of the actuator 11, the device 1 can be equipped with a sensor device 114 which determines the values of one or more measurement quantities, in order to control the process of sheet material separation. In FIG. 1, this sensor device 114 is shown merely schematically.

(12) The device 1 furthermore comprises an image acquisition unit 13 which is configured to capture an image of the surface 51 of the single sheet material piece 5-1 and to provide corresponding image data 13-1. An evaluation unit 14 of the device 1 downstream of the image acquisition unit 13 receives the image data 13-1 and in dependence on an evaluation of the image data 13-1 provides an evaluation result 14-1. An exemplary function of the image acquisition unit 13 and the evaluation unit 14 will be explained with reference to FIG. 4 and FIG. 5:

(13) FIG. 4 shows a schematic view of an exemplary sheet material piece, and for the following example it should be assumed that the sheet material piece of FIG. 4 is the uppermost sheet material piece 5-1. In the illustrated example, the sheet material piece 5-1 is a 5-Euro note. The sheet material piece 5-1 has a length L and a width B. On the abscissa axis the length I is indicated in millimeters and on the ordinate axis the width b, likewise in millimeters. For the optical analysis of the surface 51 of the sheet material piece 5-1 a grid 2 is used, which includes a plurality of identical grid elements 5-1 to 5-n. The grid elements 2-1 to 2-n each have the same grid element width RB and the same grid element length RL. In the illustrated example, the grid element width RB is 5 mm and the grid element length RL likewise is 5 mm.

(14) For example, the evaluation unit 14 is configured to determine the adhesion properties of the surface 51 of the sheet material piece 5-1 with reference to the image data 13-1. FIG. 5 shows a schematic representation of adhesion properties of the sheet material piece 5-1 shown in FIG. 4. On the left ordinate axis, the width b in turn is plotted in millimeters, and on the abscissa axis the length I, likewise in millimeters. The right ordinate axis indicates an adhesive force HK in an arbitrary unit, wherein dark shading represents a strong adhesive force and light shading represents a low adhesive force. FIG. 5 thus shows an adhesive force distribution 41 which finally represents at which points the surface 51 of the sheet material piece 5-1 has advantageous adhesion properties. Corresponding to the adhesive force distribution 41, advantageous points for example are located in a first region 512 or in a second region 513.

(15) The determination of the adhesion properties by the evaluation unit 14 can be effected in various ways. For example, one variant provides that the evaluation unit 14 independently determines the adhesion properties based on an evaluation algorithm with reference to the image data 13-1. Another variant provides that the evaluation unit 14 determines a type of the sheet material piece 5-1 with reference to the image data 13-1 and then accesses a memory (not shown in the Figures) in which predetermined standard adhesion properties each are stored for a number of types of sheet material. Based on the example concretely shown in the Figures, the evaluation unit 14 thus determines with reference to the image data 13-1 that the sheet material piece 5-1 is a 5-Euro note, and by using the memory thereupon detects that the 5-Euro note for example has the adhesion properties schematically shown in FIG. 5.

(16) In one variant, the device 1 is configured to determine a pick-up position 511 with reference to the evaluation result 14-1 and to position the sheet material pick-up 12 by means of the actuator 11 at the determined pick-up position 511 at the sheet material piece 5-1, in order to pick up the sheet material piece 5-1 at the pick-up position 511 by means of the sheet material pick-up 12 and then remove it from the sheet material stack 5. With reference to the optical evaluation of the sheet material stack 5 by means of the image acquisition unit 13 and the evaluation unit 14 a determination of a suitable pick-up position 511 is effected, at which the sheet material piece 5-1 advantageously can be picked up by means of the sheet material pick-up 12. For example, the pick-up position 511 is located in said first region 512 or in the second region 513. Thus, it is possible to pick up the respective sheet material piece to be picked up of the sheet material stack 5 at a corresponding suitable pick-up position in dependence on the quality of the sheet material piece to be picked up and in this way increase the reliability of the device 1 for separating sheet material.

(17) In another variant, which does not necessarily require the presence of the image acquisition unit 13 and the evaluation unit 14, the device 1 is configured to selectively pick up the sheet material piece 5-1 by means of a first pick-up mechanism of the sheet material pick-up 12 and/or by means of a second pick-up mechanism of the sheet material pick-up 12, in order to remove the sheet material piece 5-1 from the sheet material stack 5. In this variant, the sheet material pick-up 12 is designed to selectively actuate a first pick-up mechanism and/or a second pick-up mechanism, in order to pick up the sheet material piece 5-1. For this purpose, the sheet material pick-up includes a first means which is configured to execute the first pick-up mechanism and a second means which is configured to execute the second pick-up mechanism.

(18) The selection of the pick-up mechanism, i.e. the selection of the first means or the second means of the sheet material pick-up 12, for example likewise is effected in dependence on the quality of the sheet material piece 5-1 to be picked up. The selection on the one hand can be effected without any logic (without a software-based evaluation), in that the sheet material pick-up 12 is constructed such that the selection is effected automatically, which will be explained in detail later on with respect to FIG. 2, and/or the selection of the pick-up mechanism is effected based on a software-controlled evaluation of the quality of the surface 51 of the sheet material piece 5-1 to be picked up, for example by means of said image acquisition unit 13 and said evaluation unit 14. For example, the evaluation unit 14 determines a type of the sheet material piece 5-1 to be picked up with reference to the image data 13-1 and in dependence on the particular type of the sheet material piece 5-1 selects the first and/or the second pick-up mechanism, in order to pick up the sheet material piece 5-1 from the sheet material stack 5 with the selected pick-up mechanism or with the two pick-up mechanisms, and to remove it from said stack.

(19) With respect to FIG. 2 and FIG. 3 that variant will now be explained, in which the selection of the pick-up mechanism is effected without any logic and solely based on the mechanical construction of the sheet material pick-up 12. For illustration purposes, FIG. 2 merely shows the single sheet material piece 5-1. This sheet material piece is picked up by the sheet material pick-up 12, which for these purposes has been positioned at the sheet material stack 5 by the actuator 11 and has been attached to the surface 51 of the sheet material piece 5-1. In the illustrated example, the sheet material pick-up 12 is configured to selectively execute the first pick-up mechanism or the second pick-up mechanism.

(20) The sheet material pick-up 12 is configured to selectively pick up the sheet material piece 5-1 by generating a suction force (first pick-up mechanism) or by generating a van der Waals force (second pick-up mechanism). For these purposes, the sheet material pick-up 12 includes a suction sleeve 122 which at a coupling cap 122-1 is coupled to the guide element 113 of the actuator via a coupling piece 121. In the suction sleeve 122 a suction piston 123 is movably arranged along the perpendicular direction y, for example via a spring element 123-1. The suction piston is configured to generate a negative pressure by its movement against the perpendicular direction y in an empty space 124 defined by the suction sleeve 122, the surface 51 of the single sheet material piece 5-1 and an end face 123-2 of the suction piston 123.

(21) On the other hand, an adhesive film 123-3 is applied onto an end face of the suction sleeve 122-2 and onto the end face of the suction piston 123-2, which film is configured to generate a van der Waals force upon contact with the surface 51 of the sheet material piece 5-1. The adhesive film 123-3 for example is a so-called Gecko film, for example a Gecko Nanoplast film of the enterprise Gottlieb Binder.

(22) When the sheet material pick-up 12 now is positioned at the sheet material stack 5 by the actuator 11 and is attached to the surface 51 of the sheet material piece 5-1, said van der Waals forces therefore are generated due to the adhesive film 123-3 between the surface 51 and the end faces 122-2 and 123-2. When the actuator 11 now puts the sheet material pick-up 12 into a translational movement against the perpendicular direction y, the sheet material piece 5-1 remains stuck to the sheet material pick-up 12, in case the van der

(23) Waals force generated is large enough. If this is not the case, the suction piston 123 is shifted against the perpendicular direction y within the suction sleeve 122 due to the pulling force of the guide element 113, whereby a negative pressure and hence a suction force is obtained in said empty space 124.

(24) The selection of a suitable pick-up mechanism is expedient, because the surface 51 of the sheet material piece 5-1 to be picked up can be different at the pick-up position 511; for example, the surface 51 has a number of holes at the pick-up position 511, so that the sheet material pick-up 12 cannot pick up the sheet material piece 5-1 by forming a suction force, because the suction force does not take effect due to the holes. In this case, however, picking up the sheet material piece 5-1 succeeds by means of the adhesive film 123-3. When the surface 51 of the sheet material piece 5-1 however has a comparatively rough surface at the pick-up position 511, the van der Waals force generated might not be sufficient, which however does not preclude the separation, as the sheet material pick-up 12 in this case nevertheless can pick up the sheet material piece 5-1 from the sheet material stack 5 by generating the suction force.

(25) With reference to the above explanation of concrete exemplary embodiments, an idea should be expressed, namely that the separation of sheet material is not effected statically, but that for each sheet material piece 5-1 to 5-n a suitable pick-up position 511 and/or a suitable pick-up mechanism is selected, for example in dependence on the quality of the sheet material piece 5-1 to be picked up, in order to pick up the sheet material piece from the sheet material stack and remove it from the same. Both possibilities can be combined with each other. Hence, it is possible to determine the suitable pick-up position 511, to position the sheet material pick-up 12 at the determined pick-up position, and then to select the suitable pick-up mechanism or the means provided therefore, in order to pick up the sheet material piece 5-1 from the sheet material stack 5 and remove it from the same.

(26) With respect to the above Figures not only the exemplary device 1 for separating sheet material has been explained, but also a method for separating sheet material, e.g., a method for separating sheet material by means of the device 1 explained above.

LIST OF REFERENCE NUMERALS/USED ABBREVIATIONS

(27) 1 device for separating sheet material 11 actuator 111 base 112-1 first coupling element 112-2 second coupling element 113 guide element 114 sensor device 12 sheet material pick-up 121 coupling piece 122 suction sleeve 122-1 coupling cap 122-2 end face of the suction sleeve 123 suction piston 123-1 spring element 123-2 end face of the suction piston 123-3 adhesive film 124 empty space 13 image acquisition unit 13-1 image data 14 evaluation unit 14-1 evaluation result 2 grid 2-1, . . . , 2-n grid elements 3 sheet material support 4 scale 41 adhesive force distribution 5 sheet material stack 5-1, . . . , 5-n sheet material pieces 51 surface of the uppermost sheet material piece 5-1 511 pick-up position 512 first region 513 second region B width of a single sheet material piece L length of a single sheet material piece RB grid element width RL grid element length x x-axis/first direction y y-axis/perpendicular direction z z-axis/second direction