Apparatus and method for singling sheet material

Abstract

A singling apparatus and a system for singling sheet material comprises a sheet store for receiving a sheet stack of sheets to be singled. The sheet store includes a singling gap, which is formed and arranged to deliver a sheet out of the sheet store to a transport mechanism. The singling apparatus comprises further a singling device comprising a rotating separation roller wherein the separation roller comprises partially on its rotational surface a contact area to periodically contact and transport the sheet from the sheet store to the transport mechanism. A position control device of the singling apparatus is coupled to the separation roller and comprises an alignment indication being in correlation with an angle position of the contact area of the separation roller and indicates the alignment of the contact area to the singling gap and/or the sheet.

Claims

1. A singling apparatus for singling sheet material, the singling apparatus comprising: a sheet store for receiving a sheet stack of sheets to be singled, wherein the sheet store includes a singling gap, said singling gap being formed and arranged to deliver a sheet out of the sheet store to a transport mechanism; a singling device comprising a separation roller, the separation roller comprising partially on its rotational surface a contact area to periodically contact and transport the sheet from the sheet store to the transport mechanism; and a position indication device coupled to the separation roller and comprising an alignment indication arranged in correlation with an angle position of the contact area of the separation roller, the alignment indication indicating an alignment of the contact area relative to the singling gap and/or the sheet; wherein the position indication device is arranged on the separation roller.

2. The apparatus according to claim 1, wherein the position indication device comprises a position control roller, wherein the alignment indication is arranged on the position control roller.

3. The apparatus according to claim 2, wherein the alignment indication is integrally formed with the position control roller.

4. The apparatus according to claim 1, wherein the contact area is adapted to contact the sheet, the contact area and a rotation axis of the separation roller defining an angle of contact, and a spatial extension of the alignment indication and a center of the position indication device defining an angle of alignment, wherein the angle of contact correlates with the angle of alignment.

5. The apparatus according to claim 4, wherein a degree of the angle of alignment is equal to or more than a degree of the angle of contact.

6. The apparatus according to claim 1, wherein the alignment indication comprises one or more of: a cavity; a recess; a reflecting area; an area of a material thinning; an area of a material compacting; a magnetic marking; an electrical marking; a colored marking, comprising color pigments, luminescent pigments and/or phosphorescent pigments; and a special state of surface different to surrounding area of the alignment indication.

7. The apparatus according to claim 6, wherein the special state of surface different to surrounding area of the alignment indication comprises a difference in surface roughness.

8. The apparatus according to claim 1, wherein the alignment indication forms a circular arc or a segment of a circle or a combination thereof with a center of the position indication device.

9. The apparatus according to claim 1, further comprising a sensor device to identify an alignment of the alignment indication.

10. The apparatus according to claim 9, wherein said alignment of the alignment indication comprises an angular position of the alignment indication and/or presence of the alignment indication at a defined position.

11. The apparatus according to claim 1, further comprising a feeding mechanism configured to move the sheets to the singling gap, synchronous with an angular velocity of the separation roller.

12. The apparatus according to claim 11, wherein a geometry of the alignment indication is adapted to indicate a state of the feeding mechanism.

13. The apparatus according to claim 12, wherein the state of the feeding mechanism indicated by the geometry of the alignment indication comprises a determination whether the feeding mechanism is in contact with and/or feeds the sheets.

14. The apparatus according to claim 11, wherein the feeding mechanism comprises an air feeding mechanism and/or a feeding roller.

15. The apparatus according to claim 1, wherein the position indication device is integrally formed with the separation roller.

16. The apparatus according to claim 1, wherein the sheet store comprises a level measurement device.

17. A method for singling sheet material in a singling apparatus comprising: a sheet store for receiving a sheet stack of sheets for singling, a singling device comprising a separation roller, said separation roller comprising partially on its rotational surface a contact area to periodically contact and/or transport a sheet for separation out of the sheet stack with rotation of the separation roller in a transport rotary direction; and a position indication device coupled to the separation roller and comprising an alignment indication arranged in correlation with angular alignment of the contact area and indicating alignment of the contact area to the sheet; wherein the method comprises the steps: a) sensing a position of the alignment indication of the position indication device; b) evaluating the position of the alignment indication to determine whether the contact area is in contact with the sheet; c) where the evaluation in step b) determines that the contact area is not contacting and/or not transporting the sheet rotating the separation roller against the transport rotary direction until the separation roller is aligned to a start position, wherein the start position is defined as an angular position in which after starting to rotate the separation roller in transport rotary direction it is assured that when the contact area contacts the sheet the separation roller will have a predefined minimum angular velocity; d) rotating the separation roller in the transport rotary direction to start singling the sheet from the sheet store.

18. The method according claim 17, wherein, when rotating the separation roller against the transport rotary direction, reaching the start position of the separation roller is indicated by the position indication device.

19. The method according to claim 17, wherein the position indication device is rotatably arranged and coupled to the separation roller, the alignment indication of the position indication device configured to rotate around an axle of the position indication device and an angular velocity and/or angular position of the alignment indication configured to correlate with an angular velocity and/or angular position of the separation roller, respectively.

20. The method according to claim 17, wherein the singling apparatus further comprises a filling level meter determining a filling level of the sheet store; the method further comprising: c1) where if the evaluation in step b) determines that the contact area is in contact with the sheet and/or is transporting the sheet, and the filling level of the sheet store results that there is no sheet to be singled, rotating the separation roller against the transport rotary direction until the separation roller is aligned to the start position; or c2) where the evaluation in step b) determines that the contact area is in contact with the sheet and/or is transporting the sheet, and the filling level of the sheet store determined by the filling level meter results that there is one or a plurality of sheets to be singled, rotating the separation roller in the transport rotary to start singling the sheet from the sheet store according to step d) without rotating the separation roller against the transport rotary direction.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Although the invention will hereinafter be described in more detail with reference to the accompanying drawings by the example of the singling of bank notes, it is not restricted to this application. Any kind of sheet material can be singled in the way described hereinafter, in particular value documents other than bank notes, such as checks, shares, tickets and the like. The figures are described as follows:

(2) FIG. 1 shows schematically and exemplary an apparatus for processing bank notes;

(3) FIG. 2a, b show schematically a singling apparatus according a first embodiment in start position;

(4) FIG. 3a, b, c show a separation roller, a position control roller and a feeding roll according FIG. 2a, b

(5) FIG. 4a, b show schematically the singling apparatus of FIG. 2a, b in a first singling position;

(6) FIG. 5a, b show schematically the singling apparatus of FIG. 2a, b in a second singling position;

(7) FIG. 6a, b show schematically the singling apparatus of FIG. 2a, b in a third singling position;

(8) FIG. 7a, b shows a singling apparatus according a second embodiment of the invention in perspective view;

(9) FIG. 8 shows a singling apparatus in perspective view;

(10) FIG. 9 shows the singling apparatus of FIG. 8 in side view;

(11) FIG. 10a shows a method for singling sheet material according an embodiment of the invention at machine start-up;

(12) FIG. 10b shows a method for singling sheet material according an embodiment of the invention before start of singling;

(13) FIG. 10c shows a method for singling sheet material according an embodiment of the invention at the end of singling;

(14) FIG. 11a shows schematically a method to design a singling apparatus according an embodiment of the invention; and

(15) FIG. 11b shows schematically a method to design a singling apparatus according another embodiment of the invention.

DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS

(16) FIG. 1 shows schematically a machine 100 for processing bank notes. The machine 100 comprises a singling apparatus 1. The singling apparatus 1 comprises a sheet store 3 for receiving a sheet stack, e.g. a number of bank notes. A singling device 2 of the singling apparatus 1 singularizes the bank notes out of the sheet store 3 and delivers a singled bank note to a transport mechanism 200. The transport mechanism 200 comprises a plurality of transport rollers 202. The transport mechanism 200 transports each bank note along a transport route 201. Along the transport route 201 there are sensing devices (not shown) to sense the transported bank note and to evaluate the transported bank note e.g. according its denomination, genuineness and/or fitness. In correspondence of the evaluation result the transport mechanism 200 transports the evaluated bank note to a defined output receptacle 300.

(17) In detail the sheet store 3 comprises at an end and directed to the singling device 2 and transport mechanism 200 a singling gap 32. A feeding roll 63 of a feeding mechanism contacts the lowest bank note of the sheet stack and feeds this bank note in the direction of the singling gap 32. At the singling gap 32 the singling device 2 contacts the bank notes of the sheet store 3 using a separation roller 21 and deliver it to the transport mechanism 200. At the opposite side of the singled bank note there is a retaining element 24. The retaining element 24 prevents other bank notes of the sheet stack to be delivered by the separation roller 21.

(18) Near the separation roller 21 there is a position control device 4. The position control device 4 indicates the working status of the separation roller 21 and its orientation, in particular whether the separation roller 21 seems to deliver the bank note to the transport mechanism 200. A sensor device 5 senses the position control device 4 and recognizes the working status and/or orientation of the separation roller 21.

(19) With start of the machine for processing bank notes 100 but before start of the separation roller 21 to rotate and separate the bank notes of the sheet stack a controller checks if there is already a bank note in the singling device 2 and/or if the separation roller 21 has enough time for start-up to reach an minimum angular velocity for separation of bank notes.

(20) If the controller decides that there would be not enough time and distance to accelerate the separation roller 21, the separation roller 21 turns in a direction against the delivering direction to start position to start separation. With aligning the separation roller 21 to singularize the sheet stack at the start position it is ensured that the rotation velocity of the separation roller 21 will be enough for appropriate and reliable separation of bank notes. The bank notes will not tear and a bank note jamming will not occur in the singling device 2.

(21) FIG. 2a shows schematically a singling apparatus 1 according a first embodiment in start position.

(22) The singling apparatus 1 may be like the singling apparatus 1 of the machine for processing bank notes 100 in FIG. 1. The singling apparatus 1 may also be part of any other sheet processing machine.

(23) The singling apparatus 1 comprises a sheet store 3. The sheet store 3 is able to receive a stack of sheets 31, e.g. bank notes, to be singularized by the singling apparatus 1. In this exemplary embodiment the sheet store 3 is formed as a vessel having at least one sidewall 33 and a ground plate 34. The sheets 31 of the stack rest on the ground plate 34.

(24) At a lower end of the sheet store 3 there is a singling gap 32. The singling gap 32 is an opening to leave the lowest sheet 31 out of the sheet store 3 to a singling device 2. A feeding roll 63 of a feeding mechanism 6 contacts the lowest sheet 31 through a recess in the ground plate 34 of the sheet store 3 and feeds this sheet 31 toward the singling gap 32. The feeding roll 63 comprises on its circumferential rotational surface a frictional feeding element 62. The feeding element 62 is arranged only partial on the surface of the feeding roll 63 to perform not permanently feeding activities to sheets 31 of the sheet store 3 while rotating. Hence the feeding roll 63 feeds the lowest sheet 31 periodically. Preferably, the regional extension of feeding element 62 on the rotational surface is such that with feeding the lowest sheet 31 to the singling device 2 (feeding direction) the singling device 2 will contact and transport this sheet 31.

(25) The singling device 2 comprises a separation roller 21 to contact the sheet 31 fed from the sheet store 3 for separation. In this embodiment the separation roller 21 comprises on its circumferential rotational surface a contact area 22 to contact the sheet 31, separate the sheet 31 and deliver the sheet 31 for further processing (not shown). The contact area 22 is partially arranged on the rotational surface of the separation roller 21. So, in this embodiment the separation roller 21 delivers periodically singularized sheets 31 to following processing mechanism. For appropriate separation of sheets, the singling device 2 further comprises a retaining element 24, e.g. according this embodiment a retaining roller 24. The retaining roller 24 ensures that only one sheet 31 is able to be fed to the separation roller. The retaining roller 24 is located at the singling gap 32 at a side of the fed sheet 31 opposite to the separation roller 2 and rotates in a counter direction to the feeding direction. The retaining roller 24 contacts sheets 31 arranged above the sheet 31 to be singularized and exert a force to this above arranged sheets 31 for retaining them in the sheet store 31. A rotational separation direction s of the separation roller 21 is defined as a rotational direction wherein the separation roller 21 separates a sheet 31 from the stack of sheets 31 and delivers the singularized sheet 31 downstream to processing by rotation. In view of the separation rotational direction s the contact area 22 comprises a first end 25 and a second end 26 of the contact area 22, wherein at the first end 25 is defined as the beginning boundary of the contact area 22 and the second end 26 is defined as the end boundary of the contact area 22.

(26) The singling apparatus 1 comprises a position control device 4. The position control device 4 comprises a position control roller 42. The position control roller 42 is mounted on an axis 23 of the separation roller 21 defining a common axis 23. The position control roller 42 is coupled to the separation roller 21 by the axis 23. Rotational movement of the separation roller 21 correlates to the rotational movement of the position control roller 42.

(27) The position control roller 42 comprises an alignment indication 41. In the embodiment shown in FIG. 2a the alignment indication 41 is located at the front side 43 (base area) of the position control roller 42. FIG. 2b shows the position control roller 42 of FIG. 2a in detail and can be viewed in combination. The alignment indication 41 is a recess formed in the position control roller 42. In an alternative embodiment the alignment indication 41 may be a cavity or a coating, e.g. forming a reflective material, a magnetic marking, a colored marking, wherein the marking comprises color pigments, luminescent pigments and/or phosphorescent pigments. Further, the alignment indication 41 may have a defined electrical conductive and/or magnetic attributes. Alternatively, the alignment indication 41 may be a material thinning or material thickening at an area of the position control roller 42.

(28) The separation roller 21, feeding roll 63 and position control roller 42 are coupled to each other and therefore have the same angular velocity.

(29) FIG. 2a shows the singling apparatus in start position. Point C defines a contact Point. At the contact point the separation roller 21 is able to contact the sheet to be separated. The contact area 22 of the separation roller 21 is not contacting the next sheet to be singled. FIG. 3a shows the separation roller 21 and position control roller 42 of FIG. 2a. FIG. 3b shows the feeding roll 63 of FIG. 2a and FIG. 2c shows the position control roller 42 of FIG. 2a.

(30) The position alignment of the first end 25 defines the start position alignment (line p1) of the contact area 22. The angle of contact δ is defined by an angle in which the contact area 22 extends on the circumferential surface of the separation roller 21.

(31) The feeding element 62 of the feeding roll defines analogously to the separation roller 21 a first end 64 and a second end 65 in accordance to the extension of the feeding element 62. An angle of feeding ε is defined by an angle in which the feeding element 62 extends on the circumferential surface of the feeding roll 63. The alignment indication 41 of the position control roller 42 forms an arc-segment and comprises in separation rotational direction s a first end 44 and a second end 45. An angle of transport β is defined by an angle which is made by the first and second end 44, 45 of the alignment indication 41.

(32) FIG. 3c indicates the proportions and angular positions of contact area 22, alignment indication 41 and feeding element 62 in combination with FIGS. 2a, b. As can be seen, in separation rotational direction s the first end 25 of the separation roller 21 is behind the first end 64 of the feeding roll 62. In process to separate sheets 31 of the sheet store 3 first the feeding mechanism 6 has to contact and feed the sheet(s) 31 in the direction of the singling gap 32 so that the singling device 2, i.e. the separation roller 21, is able to contact the lowest fed sheet 31 for singularizing and delivering for further processing. Thus, the first end 64 of the feeding roll 62 is preferably ahead the first end 25 of the separation roller 21 and the second end 54 of the feeding roll 6 is ahead the second end 26 of the separation roller 21. The singling apparatus contacts the sheet 31 to be singled from that time when the feeding mechanism 6 touches the sheet 31 until the contact area 22 leaves contact to the sheet 31 (with second end 26 of contact area 22). An angle of touching α is a combination of angle of transport δ and angle of feeding ε.

(33) The angular extension of alignment indication 41 matches in this embodiment with the angle of touching α. The alignment indication 41 is able to indicate if the singling apparatus 1 is in contact with a sheet for feeding, separating and delivering by the feeding mechanism 6 and singling device 2. A sensor device can be used to detect the position of the alignment indication. The sensor device comprises an optical photo sensor 51, sensing the presence of the alignment indication 41. The sensor device is located at the position of alignment indication 41. The position of the sensor 51 is calibrated with the second end 45 of the alignment indication 41 and detects the transition of presence to non-presence of the alignment indication 41 to determine start position of separation roller 41. For example, the photo sensor 51 may comprise a light source, e.g. laser diode, and a photo diode as optical receptor and photo relay. If the sensor 51 detects the above mentioned transition it is interpreted as being at or reached start position.

(34) FIGS. 4a, b show schematically the singling apparatus 1 shown in FIGS. 2a to 3c during separation process in a situation when the singling apparatus 1 first contacts the stack of sheets 31 in a singling period, e.g. after rotation the separation roller 41 in separation direction s until the singling apparatus 1 touches the sheet 31 to be separated. I.e., the first end 64 of the feeding element 62 of the feeding roll 63 contacts the lowest sheet 31 of the stack of sheets 31. A first angle of rotation ϕ.sub.1 describes the rotation angle from the start position line p1. During rotation of the separation roll 21 in separation direction s from the start position in first angle of rotation ϕ.sub.1 the sensor 51 detects no presence of alignment indication 41 because there is no recess arranged in the sensed area. With reaching the first angle of rotation ϕ.sub.1 the sensor 51 detects a transition of alignment indication 41, i.e. the sensor 51 detects the first end 44 of the alignment indication. This event is interpreted as first contact of singling apparatus 1 to the lowest sheet 31.

(35) FIGS. 5a, b show the singling apparatus 1 according to FIGS. 2a to 4b during separation process in a situation when the contact area 22 of the separation roller 21 first contacts the sheet 31 fed by the feeding roll 63. A second angle of rotation ϕ.sub.2 describes the current angle of rotation from start position line p1. During rotating the separation roll 21 in separation direction s from the position shown in FIGS. 4a, b to the position shown in FIGS. 5a, b the sensor 51 is still detecting the presence of alignment indication 41. This will be interpreted that a sheet 31 is in the singling device 2 and the singling apparatus 1 currently contacts, feeds, transports and delivers the sheet 31.

(36) FIGS. 6a, b show the singling apparatus 1 according to FIGS. 2a to 5b during separation process in a situation when the feeding element 62 of the feeding roll 63 is feeding the sheet 31 and the contact area 22 of the separation roller 21 is delivering the sheet 31. The sensor 51 is still detecting the presence of the alignment indication 41. Thus it is interpreted that there is a sheet 31 in the singling device 2.

(37) FIG. 7a, b show the singling apparatus 1 according to FIGS. 2a to 6b during separation process in a situation when the second end 26 of the contact area 22 of the separation roller 21 is just contacting the sheet 31 to be delivered by the separation roller 21. The feeding element 62 has already lost its contact to the sheet 31. A third angle of rotation ϕ.sub.3 describes the actual angle of rotation from the start position line p1. At the third angle of rotating ϕ.sub.3 the sensor 51 is still detecting the presence of alignment indication 41. Thus it is interpreted that there is a sheet 31 in the singling device 2.

(38) When the separation roller 21 continues to turn the sensor 51 still detects the presence of the alignment indication 41 until the start position line p1 is reached. Then the sensor 51 detects the start position with a detected transition of presence of alignment indication 41 to non-presence of alignment indication 41 (see FIGS. 2a-3c). The angular range between the third angle of rotation ϕ.sub.3 and start position line p1 may be set individually. In particular this angular range is dedicated to set the angular position of the separation roller to the start position. Otherwise, there might be set a safety value to ensure that sheet 31 is not contacted by contact area 22 and feeding element 62.

(39) After the separation roller 21 reaches the start position line p1 and therefore the start position the separation process may start with separating the next sheet 31 of the stack of sheets 31 according FIGS. 2a to 3c.

(40) When starting the separation process at start-up or restart of the singling apparatus 1 the singling apparatus 1 is monitored. In particular it is determined whether a sheet 31 is to be contacted and/or delivered by the singling device and/or a sheet 31 is to be fed by the feeding mechanism 6. The start position ensures that at rotational start-up of the feeding roll 63 and/or separation roller 21 they are ramped up to at least a minimal operation speed (transport speed) when, preferably before, contacting the sheet 31 to be separated. Furthermore, the start position ensures, that neither separation roller 21 nor feeding roll 63 delivers or feeds any sheet 31.

(41) In case of new start or restart the sensor device checks the alignment position of the separation roller 21 and/or feeding roll 62. To facilitate this the sensor 51 senses the presence of the alignment indication 41. If the sensor 51 detects absence of the alignment indication 41 (angular position of alignment indication 41 is between start position and first angle of rotation ϕ1) it is assumed that neither the separation roller 21 nor the feeding roll 62 is in contact with a sheet 31 to be separated. Furthermore, it is assumed that the separation roller 21 and thus the feeding roll 42, which is coupled to the separation roller 21, can be rotated against the separation rotational direction s to be set to start position without damaging any sheet 31.

(42) If the sensor detects the alignment indication 41 it is assumed that there might be a sheet in the singling device 2 and/or is fed by the feeding mechanism. If a filling level meter of the sheet store 3 results that there is no sheet in the singling apparatus 1 the feeding roll 42, which is coupled to the separation roller 21, can be rotated against the separation rotational direction s to be set to start position.

(43) If the filling level meter results that there is a sheet in the singling apparatus 1, rotation against separation rotational direction s might lead to jamming. Thus the separation process will start without start position alignment (rotation of separation roller 21 against separation rotational direction s) and starts with singling based on this alignment position.

(44) Using the above described system a start position alignment of the singling apparatus 1, in particular of the separation roller 21 and/or feeding roller 42 is ensured wherein the presence of sheets 31 in the singling device 2 is regarded. Failures on jamming sheets 31 are prevented.

(45) FIGS. 8 and 9 show a singling device 2 and a feeding mechanism 6 according to an embodiment of the present invention. This embodiment is similar to the embodiment according to FIGS. 2a, b. Some of the differences of the embodiments of FIGS. 8 and 9 are figured out below.

(46) The singling device 2 comprises multiple separation rollers 21. The separation rollers 21 are almost formed like wheels. Each separation roller 21 comprises partially on its circumferential edge a contacting area 22 to contact, to separate and to deliver a sheet to a transport mechanism 200. Each separation roller 21 is mounted on a common axis 23. The axis 23 rotates to separate sheets in a separation rotational direction s. The contacting area 22 has in separation rotational direction s a first end 25 and in counter direction a second end 26.

(47) A position control roller 42 of a position control device 4 is mounted on the axis 23, too and rotates with the rotation of the separation roller 21. The position control roller 42 is formed like a disc. The position control roller 42 comprises a semicircular recess defining an alignment indication 41. The position control device 4 is in combination with a sensor device 5. The sensor device 5 comprises a transmission sensor to detect the presence of the recess, i.e. of the alignment indication 41.

(48) The axis 23 is joined with a motor 400 by a motor belt 410 to drive the axis 23. Furthermore, the axis 23 is coupled with a second axis 66 of a feeding mechanism 6. The second axis 66 bears multiple feeding rolls 63. Each feeding roll 63 has a disc-like structure wherein the center of the feeding roll 63 is mounted on the second axis 66. Further, each feeding roll 63 comprises partially on its circumferential surface a feeding element 62 having in separation rotational direction s a first end 64 and against direction a second end 65.

(49) In this example, the angular extension of the contact area 22 is more than the angular extension of the feeding element 62. The angular position of the first end 25 of the contact area 22 corresponds to the angular position of the first end 64 of the feeding element 62.

(50) The position control device 4 and alignment indication 41 are arranged such that when the separation roller 21 is in an angular alignment in which the contact area 22 does not contact a sheet, the position control device 4 does not detect the presence of alignment indication 41.

(51) In the case of start of the singling apparatus 1 first the sensor device 5 is requested (before singling) to detect alignment indication 41. If the sensor device 5 detects alignment indication 41 the singling apparatus triggers the separation roller 21 to rotate to the start position in a direction against separation rotational direction s. If the sensor device 5 does not detect alignment indication 41 the singling apparatus 1 asks a filling level meter about the amount of sheets in the singling apparatus. If the filling level meter responds that there is no sheet in the singling apparatus the singling apparatus triggers the separation roller 21 to rotate to the start position in a direction against separation rotational direction s. If the filling level meter results that there is at least one sheet in the singling apparatus 1 the singling apparatus notifies e.g. a supervisory system that singler device 2 is not in start position at start-up. The supervisory system and/or singler device 2 might ask for user intervention, in particular to check if a sheet is in the singler devices 2 and to remove it, if necessary and/or ask a user to confirm start singling in current position and/or ask a user to operate manually, e.g. to rotate the separation roller 21 to start position.

(52) While the separation roller 21 rotates against separation rotational direction s the sensor device 5 uses edge detection logic to detect reaching the start position. In doing so the sensor device 5 senses a transition from a status of detecting alignment indication 41 to not-detecting alignment indication 41. The detected transition assumes that start position is reached and the separation roller 21 stops to rotate.

(53) In the embodiment of FIGS. 8 and 9 the angular extension of the alignment indication 41 is 180°. The angular extension of the alignment indication 41 is not a statutory value and may differ. In particular the angular extension may depend on different parameters, e.g. angular extension on contact area and/or tolerance range. Further, the angular alignment of alignment indication 41 is the same as of contact area 22. In another embodiment the angular alignments may differ but are coupled to each other so that their relative angular alignment is equal.

(54) FIG. 10a shows a schematic diagram of a method for singling sheet material at start-up, i.e. restart, of a singling apparatus and/or singling device. In Step S1.1 the singling apparatus and/or singling device starts to process sheet material. In Step S1.2 the machine senses and evaluates whether a feeding mechanism and/or a singling device is contacting a sheet. If a sheet is contacted the machine checks (S1.3) whether a sheet is inside the singling apparatus, e.g. inside the singling device. In case there is any sheet in the singling apparatus and/or singling device, the singling apparatus starts with singling process (S1.4).

(55) If neither the singling device nor the feeding mechanism contacts a sheet nor a sheet is in the singling apparatus, the machine, i.e. the singling apparatus, rotates (S1.5) a separation roll of the singling device against separation rotational direction until a start position is reached (S1.6). Then the machine checks if there is a sheet inside the singling apparatus (S1.7). Subsequently, if there is a sheet to be separated in the singling apparatus the machine starts with singling process (S1.4). Otherwise the machine stops and end process (S1.8)

(56) FIG. 10b shows a method for singling a sheet material after a break, in particular break down, or during sheet processing of the apparatus but before its singling process. The shown method may follow up the method shown in FIG. 10a but may exist without the process according to FIG. 10a.

(57) For better and simple understanding the method shown in FIG. 10b starts with singling process S1.4/S2.1, e.g. according to FIG. 10a. Afterwards, in Step 2.2 the singling apparatus senses and evaluates if a feeding mechanism and/or a singling device are contacting a sheet. If the evaluation of Step S2.2 results that the feeding mechanism and/or singling device is contacting a sheet the singling apparatus starts immediately with singling (S2.3). Otherwise, if the evaluation (S2.2) results that the feeding mechanism and/or singling device do not contact a sheet in Step 2.4 the separation roll rotates against separation rotational direction until start position is reached. When the separation roll is aligned in start position (S2.5) the singling apparatus starts with singling (S2.3).

(58) In an embodiment after step S2.5 but before step 2.3 there may be a step S2.6 to evaluate whether there is a sheet inside the singling device and/or sheet store to be separated. If there is a sheet to be separated the process continues with Step S2.3. Otherwise, in a preferred embodiment, the process ends (S2.7).

(59) In an embodiment after step S2.3 the process continues with step S2.1. In a further embodiment step S2.2 is optional and is omitted, at least at first loop after step S1.4 but may be mandatory after step S2.1.

(60) FIG. 10c shows a process according to present invention after singling a sheet material, e.g. after singling process. This may be the case, when there is no further sheet to be singled and/or apparatus break down. The shown method follows up to the method shown in FIGS. 10a, b but may exist without at least one of preprocesses in FIGS. 10a, b.

(61) In Step S2.7/S3.1 singling of sheets or the singling process is ended. E.g. this may be in result that a filling level meter doesn't detect any sheet in a sheet store of the singling apparatus, i.e. all sheets in the sheet store are singularized and delivered to a transport mechanism for further processing.

(62) When the end of singling process is detected (S2.7/S3.1) the separation roll is rotated against separation rotational direction (S3.2) until the start position is reached (S3.3). When the start position is reached work of singling apparatus is ended (S3.4). If start position is not reached process continues either with step S2.1 or step S3.1. In a further embodiment a uses will be informed that start position is not reached. Further actions, e.g. manual operations or immediate apparatus stop can follow.

(63) In an embodiment step S3.2 can be omitted if separation roll is already in start position.

(64) FIG. 11a shows schematically a design of a singling device 2 in accordance with an embodiment of the present invention. The singling device 2 comprises a separation roller 21 adapted to rotate around an axis 23. The separation roller 21 comprises on its circumferential surface a frictional contact area 22 having a circular extension δ. The contact area 22 shown in continuous line represents a situation when the contact area 22 is just not contacting a sheet 31 anymore, e.g. the contact area 22 has just delivered a sheet 31. The contact area 22 shown in dot-dashed line shows the contact area 22 in a situation when the contact area just contacts a sheet 31 at first time for separation and delivering. The rotation direction of the separation roller 21 when delivering the sheet 31 is marked with arrow s.

(65) The separation roller 21 comprises an integrally formed position control roller 42. The position control roller extends on the front side of the separation roller 21 and comprises a recess 46, formed radially around the axis 23. The radially extension γ of the recess 46 corresponds to a circular extension of 360°-δ. The recess 46 acts as an alignment indication.

(66) A first end 44 of the recess 46 is defined at an end of the recess in direction s. A second end 45 of the recess 46 is defined at an end of the recess 46 against direction s. A point-formed in preferable stationary light source 47 of a sensor device is arranged so that its light is able to shine through the recess 46. In particular, in the present application at an alignment position of the separation roller 21 wherein the contact area 22 is in position shown with continuous line, the light source 46 shines through the recess 46 just at the first end 44. When the separation roller 21 rotates in separation direction S, the light will continuously shine through the recess 46 until the contact area 22 contacts the sheet 31 (shown in dot-dashed line). When contacting the sheet 31, the light of light source 46 exceeds second end 46, i.e. the light does not shine through recess 46.

(67) A detection unit (not shown) may be positioned to detect whether light is passing through the recess 46. So the detection unit may detect the relative angular position of the separation roller 21, in particular whether the contact area 22 is in an angular position to contact the sheet 31. In case the detection unit detects light shining through the recess 46 it is assumed that contact area 22 does not contact the sheet 31. Then, as long as the detection unit detects light passing through the recess 46 the sheet 31 won't get crumbled when separation roller 21 is rotating against direction s. Rotation against direction s should be stopped when light exceeds first end 44 and detection of light transmits to non-detection. The case of non-detection of light represents an angular position of separation roller 21 in which rotation against direction S should be carefully verified.

(68) The extension of γ of the recess 46 depends amongst others on the size of the contact area 22 and radial distance of the contact area 22 to the axis 23 (see FIG. 10b). Furthermore the extension γ of the recess can include a safety distance, e.g. a distance from the position when the contact area 22 just does not contact the sheet after delivering a sheet (first end 44) or a distance from the position when the contact area 22 just does not contact the sheet before delivering a sheet (second end 45). In first case, the first end 44 of the recess 46 is located in a direction against direction s and in the second case, the second end 45 of the recess 46 is located in direction s. In both cases the extension of γ becomes smaller.

(69) To detect the alignment position of separation roller 21, in particular of contact area 22, there may be multiple alternatives in the scope of the invention to be used as alignment indication. For example, the position of the recess 46 is variable. Hence, the orientation of the detection unit and/or the light source 45 has to be adapted to the position of the recess 46. Furthermore, instead and/or in addition to the recess 46 there may be any other design to detect a local presence. For example a route of electrical conductive material can be used, wherein the detective unit senses the presence of the conductive material. Furthermore the recess 46 or other may be positioned at a separate position control roller, coupled to the separation roller 21.

(70) The above described methods may contain additional steps, e.g. to evaluate that the feeding mechanism and/or singling device is contacting a sheet. The steps are described in any combination with FIG. 1 to 9 or 11a, b and may be transferred in the method described in any of FIGS. 11a-c. It should be obvious that other embodiments e.g. alternative methods to sense the status of contacting the sheet by the separation roller and/or the feeding roll, are included in the present invention. In particular different methods to determine the position of the alignment indication, e.g. with the help of optical, electrical and/or acoustical sensors, are possible. For example it should be independent if the presence of alignment indication is detected or its non-presence. The same applies to the devices and/apparatus shown in FIGS. 1 to 9 and 11a, b.