Device for separating sheet material

Abstract

An apparatus for singling sheet goods which comprises a suction device with a stator and a rotor movable relative to the stator. The stator has at least one first opening and the rotor at least one second opening which overlap upon a rotation of the rotor and thereby define an opening area with a first end and a second end. The opening area extends starting from the first end up to the second end, wherein a section of the opening area between the first end and the second end forms a suction area in which sheet goods to be singled can be sucked by the suction device. The first end of the opening area is arranged spaced from the suction area so that arising noise can be dampened.

Claims

1. An apparatus for singling sheet goods, comprising a suction device with a first section and a second section movable relative to the first section, wherein the first section has at least one first opening and the second section at least one second opening which overlap upon a motion of the second section relative to the first section and thereby define an opening area with a first end and a second end, wherein the opening area extends starting at the first end up to the second end and a section of the opening area between the first end and the second end forms a suction area in which sheet goods to be singled can be sucked by the suction device, wherein the first end of the opening area is arranged spaced from the suction area; the first section of the suction device is configured as a substantially cylindrical stator and the second section as a substantially cylindrical rotor arranged and rotatable around the stator; the first opening of the stator extends along a longitudinal direction and has an opening edge, which extends along the longitudinal direction of the first opening; the opening edge defines the first end of the opening area and the first opening extends from the opening edge along the circumference of the stator over an angle of at least 120; and the at least one second opening extending along a circumference of the rotor over an angle that is smaller than the extension of the first opening.

2. The apparatus according to claim 1, wherein the first end of the opening area is spaced from the suction area along the circumference of the suction device by at least 45.

3. The apparatus according to claim 1, wherein the opening edge runs at an angle to the longitudinal axis of the stator.

4. The apparatus according to claim 1, wherein the opening edge is beveled.

5. The apparatus according to claim 1, furthermore comprising a cover which covers the first end of the opening area.

6. The apparatus according to claim 5, wherein the cover is devised to dampen a noise which arises at the start of the overlap of the first opening and the second opening at the first end of the opening area.

7. The apparatus according to claim 1, wherein the second section has a plurality of the second openings, which are arranged in rows transversely to the moving direction of the second section.

8. The apparatus according to claim 7, wherein the plurality of the second openings are arranged offset in neighboring rows.

9. The apparatus according to claim 7, wherein the plurality of the second openings have different sizes in different rows.

10. The apparatus according to claim 1, furthermore comprising a guiding device which defines a start of the suction area.

11. The apparatus according to claim 1, wherein the first section has an attachment for applying a vacuum, which is connected to the at least one first opening.

12. An apparatus for processing sheet goods, comprising at least one apparatus for singling sheet goods according to claim 1.

13. An apparatus for singling sheet goods, comprising a suction device with a first section and a second section movable relative to the first section, wherein the first section has at least one first opening and the second section at least one second opening which overlap upon a motion of the second section relative to the first section and thereby define an opening area with a first end and a second end, wherein the opening area extends starting at the first end up to the second end and a section of the opening area between the first end and the second end forms a suction area in which sheet goods to be singled can be sucked by the suction device, wherein the first end of the opening area is arranged spaced from the suction area; the suction device further comprising a cover which covers the first end of the opening area, a section of a surface of the cover being concentric with the first section.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will hereinafter be described by way of example with reference to the schematic drawings. Therein are shown:

(2) FIG. 1 an apparatus for singling sheet goods from the prior art,

(3) FIG. 2 an apparatus for singling sheet goods according to the invention,

(4) FIG. 3 the stator from the apparatus according to FIG. 2 and

(5) FIGS. 4a-4d different schematic representations of openings of a rotor of an apparatus for singling sheet goods.

DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS

(6) In FIG. 1, an apparatus 1 is schematically represented for singling sheet goods, in particular bank notes, as it is known from the prior art. The apparatus 1 has a suction device 2 in the form of a singler roller having a stator 10 and a rotor 20 rotatable around the stator 10. The moving direction of the rotor 20 is marked by the arrow 3. In contrast to the prior art, the suction device 2 is arranged in a housing 6. A stack of sheet goods 100, for example a stack of bank-notes, is fed to the apparatus 1 and lies against a guiding device 4 in the form of an air baffle plate, which conveys the uppermost piece of sheet goods 100 by means of compressed air from the stack in the direction of the suction device 2. The schematic structure and basic function of the air baffle plate is known from DE 28 14 306 A1, for example. During singling, the remaining stack, in particular the pieces immediately following the uppermost piece of the sheet-goods stack, is held back by means of a retaining device 5 to avoid double and multiple picks. The retaining device 5 can likewise act by means of compressed air and be configured like an air baffle plate, which utilizes the hydrodynamic paradox occurring in the air baffle plate in connection with the stagnation pressure forces for the purpose of holding back the pieces of sheet goods following the uppermost piece. Likewise, the retaining device 5 can act with a vacuum to hold back the pieces of sheet goods following the uppermost piece. The retaining device 5 can be also configured as a roller, which rotates opposite to the singler roller 2. For the retention of the sheet goods, the roller has friction areas or likewise acts by means of a vacuum. After the singling, the singled sheet goods are transported off in a transport direction 8 by means of a transport device 7.

(7) The singling of the sheet goods 100 is effected by means of a vacuum so that the sheet goods 100 to be singled are sucked by the suction device 2, drawn from the stack and then released. For this purpose the stator 10 has an access 14, which is connected to an apparatus for generating a vacuum (not represented). Here, the access 14 is configured as a central bore along the longitudinal axis of the stator 10, it can, however, be configured arbitrarily in order to subject the stator 10 to a vacuum. The access 14 is connected with an opening 11 of the stator 10 which extends along the length of the stator 10 and in the circumferential direction from an opening edge 12 up to an edge 13. The opening 11 forms an open sector of the stator 10 which can extend, for example, over an angle of 60.

(8) The rotor 20 has several openings 21 which upon a rotation of the rotor 20 around the stator 10 overlap with the opening 11 of the stator 10. The overlap begins upon the rotation of the rotor 20 at the opening edge 12 and ends at the edge 13. An opening area 30 having a first end 31 and a second end 32 is thereby defined, i.e. that area along the circumference of the suction device 2 which the applied vacuum can reach through the openings 21. Simultaneously, a suction area 40 having a first end 41 and a second end 42 is thereby formed along the circumference of the suction device 2 in which sheet goods 100 to be singled can be sucked.

(9) In the known apparatus 1 represented in FIG. 1, the opening area 30 and the suction area 40 are congruent. With regard to the moving direction 3, the first end 31 of the opening area 30 or the first end 41 of the suction area 40 lies before an edge of the air baffle plate 4 or, where applicable, at the same level relative to the circumference of the suction device 2. The sheet goods to be singled 100 is sucked in the suction area 40 and released upon reaching the second end 32 of the opening area 30 or the second end 42 of the suction area 40, because the openings 21 of the rotor 20 are again closed by the rotation of the rotor 20. After the intermittent drive by the singler roller 2, the sheet goods can then be transported off by means of the transport device 7.

(10) As soon as the openings 21 of the rotor 20 reach the opening edge 12 of the stator 10, they open abruptly, whereby an opening bang arises. This arises in the singler gap being exposed and passes undampened in the direction of an operating person. For a fast singling apparatus with a high rotating speed of the singler roller, this opening bang can occur, for example, 44 times per second.

(11) In FIG. 2, an embodiment example of the present invention is represented. The apparatus 1 for singling sheet goods 100 resembles in wide sections the known apparatus described in connection with FIG. 1. It differs, however, in the realization of the opening 11 of the stator 10. In comparison to the known apparatus, the opening 11 extends over a much farther circumferential portion of the stator 10 so that the first end 31 of the opening portion 30, which is formed by the opening edge 12 of the opening 11, is spaced from the suction area 40. In other words, according to the invention, the opening area 30 and the suction area 40 do not coincide, rather the suction area 40 is merely a section of the opening area 30. Accordingly, the corresponding first ends 31 and 41 also do not coincide, rather the first end 31 of the opening area 30 is spaced from the first end 41 of the suction area 40. In this embodiment example, the distance of the first ends 31 and 41 along the circumference amounts to about 150.

(12) By shifting the first end 31 of the opening area 30 away from the suction area 40, i.e. away from the singler gap being exposed, the opening bang arising at the first end 31 can be dampened. For this purpose, the cover or the housing 6 is configured as a noise-dampening material. It surrounds the area of the singler roller 2 in which the first end 31 of the opening area 30 is arranged and preferably also the front faces of the singler roller 2. In this manner the noise level of the apparatus 1 during operation can be reduced considerably. Exemplary measurements of the sound level in the center of the singler roller 2 in a distance of 20 mm yielded a reduction of 1.5 dB(A) without the housing 6. With a housing a further reduction can be attained, for example of about 1 dB(A).

(13) Furthermore, the energy consumption of the apparatus can be reduced because the vacuum necessary for the singling does not need to be available abruptly, as this is the case in the apparatus according to FIG. 1, where the first end 31 of the opening area 30 and the first end 41 of the suction area 40 coincide. In the apparatus 1 according to FIG. 2, the first end 31 of the opening area 30 is spaced from the first end 41 of the suction area 40 so that this distance can be utilized for attaining a sufficient vacuum in the openings 21. For this, the total vacuum applied in the stator 10 can be less than in the known apparatus according to FIG. 1. The generation of the vacuum from excess pressure by means of the ejector principle can be effected through the reduced energy demand of the apparatus and by simultaneously employing the principle of the air baffle plate for the retaining device 5 (see above). It is thereby possible to dispense with a separate aggregate for the vacuum generation, which results in further improvements as to energy consumption and noise reduction.

(14) In FIG. 3, the stator 10 of the apparatus 1 of FIG. 2 is represented in a perspective view. A fitting 16 serves for attaching to an apparatus for generating a vacuum which is applied to the opening 11 at the access 14. The opening edge 12 of the opening 11 can be recognized, which is obliquely arranged with regard to the longitudinal axis of the stator 10 to further reduce the noise level, i.e. it runs not parallel but at an angle to the longitudinal axis. In this way it is attained that not all openings 21 of the rotor 20 open simultaneously but gradually. A gentle opening is further attained by a bevel 15 at the opening edge 12. The opening bang is thereby reduced when the openings 21 of the rotor 20 hit the opening edge 12.

(15) In FIG. 4, the different patterns in which the openings 21 can be arranged along the rotor 20 are schematically represented. In FIG. 4A, the openings are all equally large and arranged uniformly in rows. A time-shifted opening can be attained by an offset of the openings 21 as in FIG. 4B, similar to the slant of the opening edge 12 of the opening 11, whereby a noise reduction can be attained. Alternatively or additionally, the openings 21 can have different sizes, as is represented in FIGS. 4C and 4D. The openings 21, which reach the opening edge 12 first, are configured smaller.

(16) In this way, an abutting of the sheet goods 100 against the rotor 20, which can likewise cause an annoying noise, is reduced. A gentler clinging of the sheet goods 100 to the rotor 20 can be attained by the differently large openings 21 because the sheet goods 100 are drawn toward the rotor 20 with increasing force and not abruptly.