Device for separating individual, two-dimensional, flexible objects from the lower side of a stack

Abstract

A device for separating individual, two-dimensional, flexible objects from the lower side of a stack of such objects and for conveying the separated objects away from the stack. The device includes a stack space with a support region, and a support member that supports the stack from below in the support region. The support member includes a support roller arrangement of a plurality of support rollers. The device further includes at least one separating member for separating the objects from the lower side of the stack in the support region. The support roller arrangement is part of a roller guidance device and is translatorily movable to and from between a support position and a release position.

Claims

1. A device for separating individual, two-dimensional, flexible objects from a lower side of a stack of two-dimensional, flexible objects and for conveying the separated objects away from the stack, comprising: a stack space with a support region; a support member that supports the stack from below in the support region, wherein the support member comprises two support roller arrangements with at least one support roller and a stationary support arrangement; and at least one separating member for separating the objects from the lower side of the stack, wherein the two support roller arrangements are arranged next to one another considered in the movement direction of the support roller arrangements, wherein between the support roller arrangements a central gap is formed which extends along the movement direction of the support roller arrangements and through which the at least one separating member can be moved towards the support region for the purpose of gripping the lowermost object of the stack, wherein the support roller arrangements are part of a roller guidance device, and the support roller arrangements are periodically movable between a support position and a release position, wherein the stationary support arrangement forms together with the support roller arrangements, located in the support position, a common support surface for the stack, wherein the movement of the support roller arrangements, at least along the support surface, is translatorily and parallel to the support surface, and wherein between the stationary support arrangement and the support roller arrangements, located in the release position, a release gap is formed, and wherein the width of the release gap can be enlarged or reduced due to the movement of the support roller arrangements between the support position and the release position.

2. The device according to claim 1, wherein the support roller arrangements at least in sections are movable along an arcuate movement path.

3. The device according to claim 1, further comprising a controller that is operable to control movement of the support roller arrangements in a cyclically synchronous manner to the separating procedure.

4. The device according to claim 1, further comprising biasing members that are capable of exerting a restoring force in the direction of the support position or release position of the support roller arrangements.

5. The device according to claim 1, further comprising a blowing air feed device that is adapted to blow air in between a lowermost object of a stack, which is at least partly bent away by the separating member, and the stack.

6. The device according to claim 1, wherein a stationary guide roller, which is arranged in the support region, connects to the stationary support arrangement towards the support roller arrangements.

7. The device according to claim 1, wherein the at least one separating member is arranged on a take-over device arranged below the support region.

8. The device according to claim 1, further comprising at least one transport member for transporting the separated objects away from the stack, and the at least one transport member is arranged on a take-over device arranged below the support region.

9. The device according to claim 7, further comprising a deactivation device that is operable to stop movement of the support roller arrangements given a continued revolving movement of the at least one separating member.

10. The device according to claim 1, further comprising a rear stack space limitation member that forms an essentially vertical limitation surface, and towards the support region comprises a wall section that is angled or bent in the direction of the support roller arrangements.

11. The device according to claim 1, wherein the support roller arrangements form a roller carpet.

12. A method for separating individual, two-dimensional, flexible objects from a lower side of a stack of two-dimensional, flexible objects and for conveying the separated objects away from the stack by way of the device according to claim 1, wherein the support roller arrangements are located in the support position for supporting the stack, comprising the following steps: moving the support roller arrangements at least along the support surface translatorily and parallel to the support surface along a release direction out of the support position to enlarge the release gap; moving the at least one separating member through the central gap towards the support region; gripping the lowermost object of the stack by way of the at least one separating member; separating the lowermost object from the stack by way of bending the object away from the stack lower side into the release gap; moving the support roller arrangements in a support direction opposite to the release direction to reduce the release gap; transporting away the object through the release gap.

13. The method according to claim 12, wherein the support roller arrangements are moved in the support direction already during the bending of the object away from the stack lower side.

14. The method according to claim 12, wherein the at least one separating member grips the object while the moving support roller arrangements enlarge the release gap.

15. The method according to claim 12, wherein the object is bent away from the stack lower side while the support roller arrangements move in the support direction.

16. The method according to claim 12, wherein the device comprises a controller that is operable to control movement of the support roller arrangements in a cyclically synchronous manner with the separating step of the objects.

17. The method according to claim 12, wherein the device comprises a blowing air feed device that is operable to blow air in between the at least partly bent-away, lowermost object and the stack, during the bending of the lowermost object away from the stack, by way of the blowing air feed device.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The subject-matter of the invention is hereinafter explained in more detail by way of preferred embodiment examples which are represented in the accompanying drawings. There are shown in:

(2) FIG. 1 is a perspective view of a device according to the invention;

(3) FIG. 2 is an elevation lateral view of the device according to the invention and according to FIG. 1;

(4) FIGS. 3a-3d are elevation views that illustrate the course of the method according to the invention, according to FIG. 2;

(5) FIG. 4 is a perspective view of the device according to FIGS. 1 to 3, from the region of the support roller arrangement; and

(6) FIG. 5 is a perspective view of the device according to FIGS. 1 to 3, from the region of the support roller arrangement, with an alternative embodiment of the support roller arrangement.

(7) Basically, the same parts are provided with the same reference numerals in the figures.

DETAILED DESCRIPTION OF THE INVENTION

(8) FIGS. 1 to 4 show a specific embodiment of the present invention. FIGS. 3a to 3d in particular show the method course with regard to the separation and transport of objects away from a stack.

(9) FIG. 5 shows an alternative embodiment of a support roller arrangement and of a blowing air device which however in the device according to the FIGS. 1 to 4 can be applied as an alternative embodiment to the support roller arrangement and blowing air device which are shown there.

(10) The device 1 forms a stack space 4 which receives a stack 3 of two-dimensional, flexible objects 2. The flat sides of the objects 2 are orientated perpendicularly to the gravity direction G. The object 2a of the stack 3 which is lowermost in the gravity direction G lies with its flat side on support means supporting the stack 3 from below. The support means for this form a plan support means surface.

(11) The support means comprise a stationary support arrangement 22 which forms a type of rest table for the part-surfaced support of the stack 3. Part-surfaced means that the stationary support arrangement 22 supports the stack only over a first part of the surface side of the lowermost object 2a. The rest table forms a support surface 27.

(12) A stationary, rotatably mounted guide roller 23 connects to the stationary support arrangement 22 in a release direction FR which is hereinafter yet described in more detail. This guide roller is part of the stationary support arrangement 22. Moreover, considered in the release direction FR, two support roller arrangements 7a, 7b of a roller guidance device 6 which are designed in a mirror-symmetrical manner and are arranged next to one another and distanced to one another, connect to the stationary guide roller 23. The support roller arrangements 7a, 7b in each case likewise form a part of the support surface 27 for the stack 3. The support surface 27 of the support roller arrangements 7a, 7b lies in the same plane as the support surface 27 of the stationary support arrangement 22.

(13) A central gap 32 is formed between the two support roller arrangements 7a, 7b, through which gap separating members 19 arranged on a carrier wheel 21 can be moved into the support region. The carrier wheel 21 is arranged below the support region 5.

(14) The separating members are present as suction members 19. These, as described in more detail hereinafter, are led by the rotating carrier wheel 21 along their revolving path in a cyclically controlled manner into the support region 5 and out of this again, for the purpose of gripping the objects 2a from the stack 3. The suction members 19 according to FIG. 1 comprise two suction disks. The suction members however can also comprise only one or more than two suction disks.

(15) Transport members in the form of grippers 20 which are likewise moved by way of the rotating carrier wheel 21 along a revolving path are likewise attached onto the carrier wheel 21. A suction member 19 and a gripper 20 in each case form a pairing. In total four pairs with a suction member and gripper, are arranged along the periphery of the carrier wheel in a manner distanced to one another, in the present embodiment example.

(16) The pairing is of a functional type and is characterised in that the suction member 19 transfers an object 2a bent away from the stack 3, to the gripper 20 of the pairing assigned to this, for the transport away.

(17) The two support roller arrangements 7a, 7b are then periodically and translatorily movably guided between a support position SP and a release position FP. In the support position SP, the support roller arrangement 7a, 7b connects to the stationary support arrangement 22 or to its guide roller 23. The support arrangement 22 and the support roller arrangement 7a, 7b form a common support surface. This support surface is continuous in the broadest sense.

(18) In the release position FP, the support roller arrangement 22 is maximally distanced to the stationary support arrangement 22. A release gap 33 is formed between the support arrangement or the guide roller 23, and the support roller arrangement 7a, 7b.

(19) In FIG. 1, the one support roller arrangement 7a, 7b of the roller guidance device 6 for illustration is in the support position SP and the support roller arrangement 7a, 7b arranged on the other side of the central gap 32 is shown in the release position FP. Of course both support roller arrangements 7a, 7b are led synchronously in regular operation of the device.

(20) The support roller arrangement comprises three support rollers 8 arranged one after the other in the release direction FR. The exact number of support rollers however is not essential to the invention. The support rollers 8 are rotatably mounted in laterally arranged roller carriers 9. The roller carriers 9 are designed as longitudinal profiles which extend along the release direction FR.

(21) The roller guidance device 6 moreover comprises lateral guide profiles 37 which are part of a carriage guide. The roller carriers 9 designed as carriages are thereby led in the guide profiles 37.

(22) The periodic and translatory movement of the support roller arrangement 7a, 7b is controlled via mechanical cam guidance. For this, the support roller arrangement 7a, 7b is coupled via a first and second link arm 10, 11 and via a link shaft 36, to a cam arm 12. A rotatably mounted cam roller 13 is attached at the distal end of the cam arm 12. The cam roller 13 is actively connected to a control cam 14. The control cam 14 is connected to the carrier wheel 21 in a rotationally fixed manner and accordingly rotates with the carrier wheel 21. The cam roller 13 accordingly rolls on the cam path of the control cam 14 which moves past.

(23) For executing a translatory movement, the control cam 14 via the rolling cam roller 13 activates a pivot movement of the cam arm 12. The rotational pivot movement 13 of the cam arm 12 is converted via the link connection of the first and second link arm 11, 12 into a periodic and translatory movement of the support roller arrangement 7a, 7b.

(24) The cam arm 12 for this is connected to a link shaft 36 in a rotationally fixed manner. The second link arm 11 of the link connection in contrast is rotatably mounted on the link shaft 36. The link shaft 36 is led by a biasing means in the form of a rotatory spring 15. The rotary spring 15 bears with its first limb on a first bolt 28 of a component co-rotating with the link shaft 36. Moreover, the rotary spring 15 with its second limb bears on a second bolt 28 connected to the second link arm 11.

(25) The pivot movement of the cam arm 12 causes a rotation of the shaft 36 which via the first bolt and the first limb exerts a torsion movement onto the rotary spring 15. The torsion movement is transmitted from the rotary spring 15 via the second limb and the second bolt 28 onto the second link arm 11. The second joint arm 11 is set into a rotation movement by way of this.

(26) The rotation movement of the second link arm 11 now moves the first link arm 10 which is articulately attached on the distanced end of the second joint arm 11, along an arc-shaped movement path. The first joint arm 10 with its other end is articulately connected to the support roller arrangement 7a, 7b, i.e. to the roller carrier 9 and transmits the movement into a translatory movement of the support roller arrangement 7a, 7b along the carriage guide.

(27) The rotary spring 15 moreover due to its biasing can exert a restoring force in the form of a torque onto the second link arm 11. This restoring force has the effect that the support roller arrangement 7a, 7b is guided via the link arrangement 10, 11 into the release position SP.

(28) The device moreover comprises deactivation means in the form of blocking or locking means, which are to prevent the movement of the link arms 10, 11 and thus the movement of the support roller arrangement 7a, 7b out of the support position SP. The blocking or locking means are necessary, if despite the separating member 19 continuing to revolve, no objects 2a are to be pulled from the stack 3.

(29) The control cam 14 which rotates further with the carrier wheel 21, although continuing to exert a control movement of the cam arm 12, the torsion moment exerted by the pivot movement of the cam arm 12 onto the rotary spring 15 is however accommodated and compensated by the rotary spring 15. The rotary spring 15 is additionally tensioned by this procedure.

(30) The stack space 4 in its rear end lying opposite to the release direction FR is limited by rear stack space limitation means 24. The stack space limitation means are present as a stack space limitation wall 24. The stack space limitation wall 24 forms a vertically aligned limitation surface 25. A terminating limitation surface 26 which is bent towards the support roller arrangement 7a, 7b connects onto the vertical limitation surface 25 towards the support region 5.

(31) The stack space moreover is limited in its front end lying in the release direction FR by way of front stack space limitation means 29. The front stack space limitation means 29 comprise vertically arranged angle elements 30 which define a stack space limitation in the corner regions of the rectangular objects 2 of the stack 3. The angle elements 30 at their lower termination each comprise a corner support element 31. These form a rest surface for the corner regions of the lowermost object 2a. The size of the corner support elements 31 and accordingly also the size of the rest surface are dimensioned and limited in a manner such that the objects 2a can be pulled away downwards via the corner support elements 31 without any problem.

(32) Adjustment means are moreover provided, which permit an adjustment of the front and rear stack space limitation means 24, 29. In this manner, the stack space 4 can be adapted to the different object formats by way of adjusting the stack space limitation means 24, 29. The adjustment mechanism is not dealt with in more detail at this location, since it is not essential to the invention.

(33) The method shown in FIGS. 3a to 3d for singularising objects from a stack and for transporting these away from takes its course as follows.

(34) In an initial position, the support roller arrangement 7a, 7b is arranged in its support position SP, in which this directly connects to the stationary support arrangement 22 or to its guide roller 23. I.e., in the support position SP, no or a narrow gap is formed between the support arrangement 22 or the guide roller 23, and the support roller arrangement 7a, 7b.

(35) For removal of the lowermost object 2a from the stack 3, a suction member 19 moved along a revolving path on the carrier wheel 21 is now led up and onto the lower side of the lowermost object 2a in its end section supported by the support roller arrangement 7a, 7b. For this, the suction member 19 is moved through the central gap 32 between the two support roller arrangements 7a, 7b.

(36) The support roller arrangement 7a, 7b, simultaneously or even before this, is moved in the release direction FR away from the stationary support arrangement 22. A release gap 33 opens (see FIG. 3a).

(37) The suction member 19 grips the lowermost object 2a on its front end section and bends this downwards away from the stack lower side. The bending-away downwards is effected via a superimposed movement, consisting of a pivot movement of the suction member 19 about a pivot axis as well as a rotation movement of the suction member 19 with the carrier wheel 21. The front end section of the object 2a is accordingly led downwards through the release gap 33 (see FIG. 3b).

(38) With regard to the objects 2 pulled away from the stack 3, it is the case of multi-page printed products each with a fold and a cut edge. The objects 2a are then bent away downwards with the fold in front and transported away.

(39) During the bending-away of the lowermost object 2a by way of the suction member 19, the support roller arrangement 7a, 7b is moved back in the support direction SR opposite to the release direction FR, back in the direction of the support position SP. The support roller arrangement 7a, 7b thereby moves in between the bent-away object 2a and the stack 3. In this manner, an as early as possible support of the stack 3 in the region of the release gap 33 is ensured, specifically already before the lowermost object 2a has already been pulled away (see FIG. 3b).

(40) Moreover, by way of a blowing air feed device 16, blowing air is blown in between the at least partly bent-away lowermost object 2a and the stack lower side, during the bending-away of the lowermost object 2a. By way of this, an air cushion reducing the static friction is formed between the lowermost object 2a and the stack lower side, during the bending-away of the lowermost object 2a. The reduction of the static friction permits a reliable removal of the lowermost object 2a from the stack lower side.

(41) A first embodiment variant of a blowing air device 16 is shown in FIG. 4, which shows an enlarged part detail from the region of the support roller arrangement 7a. This comprises a blowing air tube 17 arranged transversely to the movement direction of the support roller arrangement 7a and having air exit openings 38 which are directed to the stack lower side (not shown). The blowing air tube 17 is designed as part of the support roller arrangement 7a and is arranged running in front of the frontmost support roller 8 seen in the support direction SR as well as parallel to the rotation axes of the support rollers 8. The blowing air 18 on retracting or moving back the support roller arrangement 7a in the support direction SR is now blown through the air exit openings 38 towards the gap opening between the bending-away, lowermost object 2a and the stack lower side.

(42) An alternative embodiment of a blowing air feed device 46 is shown in FIG. 5. The blowing air feed device 46 analogously to the embodiment variant according to FIG. 4 comprises a blowing air tube 47 which is arranged transversely to the movement direction of the support roller arrangement 57a and having air exit openings 38 directed towards the stack lower side (not shown). The blowing air is fed via a blowing air flexible tubing to the blowing air tube.

(43) The blowing air tube 47 is likewise designed as part of the support roller arrangement 57a and, considered in the support direction SR is arranged running in front of the support rollers 8 as well as parallel to the rotation axis of the support rollers 8. Now according to this embodiment, several additional support rollers 48 which are rotatably mounted and are arranged in a manner distanced to one another along longitudinal axis of the blowing air tube 47 are arranged on the blowing air tube 47. The blowing air tube 47 forms a roller pivot designed as a hollow pivot, for the additional support rollers 48. The mounting of the additional support rollers 48 on the roller pivot can be effected via suitable ball bearings. The individual, additional support rollers 48 which are arranged next to one another transversely to the movement direction of the support roller arrangement 57a likewise serve for the support of the stack 3 in the support position SP.

(44) The blowing air 18 with this embodiment, on retracting the support roller arrangement 57a in the support direction SR, is now blown through air exit openings 38 towards the gap opening between the bending-away lowermost object 2 and the stack lower side. The air exit openings 38 are arranged between the additional support rollers 48.

(45) In a further development of the method, the suction member 19 now transfers the object 2a to a gripper which is likewise co-moved in a revolving manner with the carrier wheel 21. The gripper 20 now pulls the gripped object 2a downwards completely away from the stack 3. With this procedure, the object 2a is pulled away downwards around the guide roller 23 (see FIGS. 3c and 3d).

(46) The support roller arrangement 7a, 7b again reaches its support position SP with the pulling of the object 2a away from the stack 3. A new operating cycle can begin.

(47) The transferring suction member 19 and the taking-over gripper 20 form a pairing. The manner of operation of the suction members 19 and grippers 20, which are led in a revolving manner on a common carrier wheel 21, is already known from the state of the art mentioned in the description introduction and is therefore no longer described in all details at this location.

(48) The translatory movement of the support roller arrangement 7a, 7b is of course controlled in a cyclically synchronous manner with the movement of the suction members 19 and grippers 20. The movement of the suction members 19 as well as of the grippers 20 along their revolving path and, as the case may be, the pivot movement of the suction members and grippers about a pivot axis and the closure and opening movement of the grippers can likewise be effected via control cams.

(49) The device 1 moreover also comprises a damping element 34 in the form of an elastic loop which damps the radial deflection of the trailing end section of the object 2a, said deflection being produced by way of pulling down the object 2a.

LIST OF REFERENCE NUMERALS

(50) 1 device 2 objects 2a lowermost object 3 stack 4 stack space 5 support region 6 roller guidance device 7a, 7b support roller arrangement 8 support rollers 9 roller carrier 10 first link arm 11 second link arm 12 cam arm 13 cam roller 14 control cam 15 biasing means (rotary spring) 16 blowing air feed device 17 blowing air channel 18 blowing air 19 separating member (sucker) 20 transport member (gripper) 21 take-over device (carrier wheel) 22 stationary support arrangement 23 guide roller 24 rear stack space limitation means 25 vertical limitation surface 26 terminating limitation surface 27 support surface 28 bolt 29 front stack limitation means 30 angle elements 31 corner support element 32 central gap 33 release gap 34 damping element (elastic loop) 35 guide plate 36 link shaft 37 carriage guidance 38 air exit openings 46 blowing air feed device 47 blowing air channel 48 support rollers 57a support roller arrangement SP support position FP release position FR release direction SR support direction AR movement direction of the separating members G gravity direction