EP2336059B1 - Method for separating printed products out of a stack - Google Patents

Description

The invention relates to a method for separating printed products from a stack, with a push-off device for separating the printed products and a downstream removal device for conveying away the separated printed products according to the preamble of claim 1.

For separating printed products from a magazine, especially from bonded printed products with a thickness from about 2 mm, often so-called from a push-off device and a subsequent Abtransporteinrichtung slide feeder are used. In this technology, the singling power is limited by the relatively large mass to be moved with a corresponding stroke of the push-off device. Due to the sudden increase in the transfer of the removal device to Abtransporteinrichtung speed of the printed products, there are also disturbing marks on these printed products.

From the DE1247266 a separating device is known with which books or brochures are conveyed out of a filling magazine by means of a translationally oscillating slide to a processing machine. The form-fitting acting on the back of the bottom book slider has on its upper side resting straps, which should prevent smearing of the printed surface of the second lowest book during the movement process. The slide is moved by a rotating crank disc and thereby performs a steady movement. Therefore, the accelerations occurring during the pushing off of a printed product can not be optimized, which is disadvantageous in separating devices with high cycle times.

With the DE9208033U1 discloses a device which also with an oscillating feed element for separating blanks from cardboard, corrugated cardboard or the like is equipped. In this case, the feed element promotes by means of attached to this transporters first the bottom blank form-fitting forward, being carried after lifting the feed element and thus the conveyors and the second bottom blank by means of trained at the top of the conveyors suction openings. While the third lowermost blank is present at a rear stop bar, the movement of the second bottom blank on a front stop bar is stopped and the lowermost blank to be separated is conveyed through a passage opening to a following machine. Thus, a two-phase separation of the blanks, which is to improve the reliability. Before the return movement of the feed element, however, this must be lowered back to its original position including the transporters. In this case, the feed element performs both a large stroke in Abschieberichtung, as well as at right angles to what comparatively complicated mechanical elements requires and has both a detrimental effect on the manufacturing cost and fatigue strength, as well as on the clock rate to be achieved.

The DE19756374A1 shows a device for separating book covers from a stack, consisting of an oscillating working suction conveyor and a downstream in the transport direction feed roller pair. To functionally safe separation of the book covers is proposed to lift the suction conveyor during its working slightly above the stacking table and lower slightly below the stacking table during its return stroke. Once the front of the bottom book cover reaches the feed rollers, the upper, non-driven roller is lowered by means of working cylinders on the lower, driven roller, while the suction conveyor changes in its return stroke. Although the use of the feed roller pair allows a safe discharge of the individual book covers, the speed ratios are unfavorable in the transfer of individual book covers from Saugförderorgan to the feed roller pair. While the driven infeed roller has a constant, high peripheral speed, which is matched to the connecting conveyor, the suction conveyor has close to it Turning point left the maximum lifting speed for a long time. When re-accelerating the isolated book cover in the feed roller pair this leads to abrasion and wear on the surface of the book cover, which may have a quality impairment. Because only the lower roller of the feed roller pair is driven, must also be expected with a deformation and an oblique running of the book covers, which can lead to problems in the following aggregates. Finally, the separation efficiency is limited in this solution because of the upper feed roller with incoming book cover on the lower feed roller working cylinder.

From the EP0384979B1 a device for separating stacked book blocks is known in which as an alternative to an oscillating Abschiebetisch an endlessly circulating, equipped with Ausstosselementen conveyor line is used. While this device hardly triggers vibrations due to continuous movement of the conveyor string, a rapid interruption of the singling operation is not possible because of the ejection elements arranged at a fixed distance from one another, which is disadvantageous in the feeding of follower apparatuses.

The DE10223350A1 discloses a device for separating printed sheets from a stack, consisting essentially of support strips, a push-off device provided with push-out elements and a removal device having a take-off roller pair. The push-out elements are driven by a linear displacement motor directly assigned to the push-off device. As a result, the movement profile of the push-off device can be varied as a function of the required removal speed. In addition, the linear motor offers the possibility of directly adjusting the Abschiebehubs to the format size of the sheet, whereby the number of required format changes can be reduced. The device can be operated so that the printed sheets are discharged either with a constant, predefined pitch or format-independent with defined gaps between the sheet. The lowermost signature is accelerated to ejection speed by means of the ejector elements and then discharged at a constant speed from the downstream take-off roller pair. While this solution allows a very flexible separation of printed sheets, the high cost and high heat development of the linear motor is a disadvantage. Since the primary part of the linear motor moves with the push-out, it must be fed via a drag chain, which is problematic in a continuous operation with high accelerations. The relatively large mass to be accelerated subsequently leads to great forces, which must be absorbed by the frame of the device. Depending on the separation performance this can lead to large vibrations. In addition, the set to each other pair of delivery rollers is not suitable for processing of adhesive bound catalogs with an applied back. Finally, there is a risk of one-sided tipping of the rest of the stack when separating the bottom sheet.

The problem with the known approaches is that the movements of the push-off process are fixed and thus the acceleration of the printed products can not be optimized for high-performance singulation. In addition, the speed conditions at the transfer points, especially in the product transfer from the Abschiebetisch on the removal rollers, so unfavorable that often the quality of the printed products is affected. Due to the motion sequences rigidly predetermined by the mechanism, the movement can not be matched to the corresponding format of the printed products to be separated. The uncontrolled slipping of the rest of the stack can lead to follow-up problems in that the printed products wedge in the magazine shaft and thus do not allow process-reliable separation. Solutions that would allow for a more flexible definition of the motion of the pusher table and the discharge speed require expensive drive systems with moving feed and control lines, but which are unsuitable for high performance continuous operation, for example, more than 15,000 strokes per hour.

From the EP0414157 A2 For example, a method and an apparatus for feeding plates, for example corrugated fiberboards, to a subsequent processing machine are known. In this solution, the plates are first separated by means of a push-off device from a stack and then conveyed by means of a Abtransporteinrichtung to the subsequent processing machine. The push-off device and the removal device have mutually independent drives. In this case, the removal device is essentially below a stack receiving magazine and has a Abschiebetisch with two different conveyor elements for the plates, namely a push rod attached to the Abschiebetisch and several, the Abschiebetisch comprehensive first Zuführwalzen which part of a pull down the bottom plate of the stack are serving suction unit. The removal device is arranged downstream of the magazine and has a retainer for in-magazine plates and second feed rollers with an upper and a lower removal roller. Between the retainer and a support surface of the Abschiebetisches a first passage height and between the removal rollers, a second passage height for the plates is formed.

The object of the present invention is to provide a method for separating printed products from a stack, with which the disadvantages of the prior art mentioned are avoided and which, with a further simple structural design, enables a high separation efficiency and a gentler treatment of the printed products.

According to the invention, this object is achieved by a method having the characterizing features of claim 1.

In this case, the removal device and the removal device of the separating device each have an independent, rotary drive. Both devices are therefore driven independently of each other, wherein the printed products are accelerated in the push-off device to a first speed and in the Abtransporteinrichtung to a higher speed compared to the first speed.

The push-off device is arranged essentially below a magazine accommodating the stack and has a push-off table with at least one driver attached to it and / or with at least one vacuum opening arranged in the push-off table. By means of a fast switching valve arranged between the at least one vacuum opening and a vacuum source, the at least one vacuum opening is connected in exact timing with the vacuum source, whereby the underside of the lowermost printed product is non-positively sucked to the Abschiebetisch. This is used especially for thin printed products of secure separation. The at least one vacuum opening is clock-accurate, advantageously even compensated for a dead time, separated by the Schnellschaltventils of the vacuum source, shortly before the printed product is transferred from the removal device to the Abtransporteinrichtung. In order to achieve a particularly rapid drop of the vacuum, the evacuated volume is additionally filled with compressed air. As an alternative, the separation may be carried out instead of or in addition to the vacuum openings with the driver who the. The driver is adapted to the thickness of the printed products, but must be so high in the minimum that a positive connection with the deported print product can arise.

In this case, the drive of the removal device is controlled so that the maximum speed of the Abschiebetisches is reached only after the middle of the Abschiebehubs and pass in the transfer of the deported printing product from the Abschiebeeinrichtung to the Abtransporteinrichtung no significant speed differences. The acceleration is thus divided into two phases, whereby a gentler treatment of the printed products can be achieved. The translational movement of the removal device is realized by means of a cost-effective and durable, limited and drive-connected with the Abschiebetisch crank mechanism. Alternatively, a crank loop can also be used to generate the movement.

In a further embodiment of the invention, the drive of Abtransporteinrichtung is controlled so that their speed does not remain constant after taking over the printed product to be deported by the push-off device, but changed in the course of further transport of the printed product, for example, increased until the for a follower unit of Separation device required feed rate is achieved. Thus, the printed product to be deported is accelerated in two phases to the speed required for removal, which contributes to the protection of the printed product. In addition, the movement of the drive and thus the Abtransporteinrichtung can be adjusted depending on the length of the printed products so that a minimum acceleration acts on the printed product to be transported. Finally, the required feed rate can be easily and quickly adjusted by the movement of Abtransporteinrichtung is changed accordingly. This allows a rapid change of the pitch, ie the distance between the printed products.

According to a preferred embodiment of the invention, the upper removal roller is at least one of the conveying of the previously separated printed product serving roller pair once per separation cycle by a stroke moves up and down. Since, in particular, adhesive-bound printed products which are conveyed transversely to the spine of the book can be damaged by press rollers on the spine, the purely non-positive engagement of the at least one pair of rollers must take place just behind the spine. Before the subsequent printed product reaches the at least one pair of rollers, the upper removal roller is moved back up to the starting position. Advantageously, the upper removal roller and thus its lifting movement is coupled to the drive of the removal device, since both systems have the same clocked sequence. It is also conceivable, however, a coupling of the upper removal roller with the drive of Abtransporteinrichtung. In order to be able to control the lifting movement independently of other conditions, a separate drive can advantageously be arranged for this function.

In a further embodiment of the invention, the at least one upper removal roller is arranged on a shaft mounted in a lifting shaft. The lifting carriage is designed to be vertically movable on a frame of the device. On lifting a driven by a drive shaft cam is provided on the circumference under the action of a directly connected to the lifting spring rolls a cam roller, the cam is equipped in particular with a drive of the deporting device and the drive of Abtransporteinrichtung separate drive. Advantageously, the movement of the lifting carriage of the upper removal roller, e.g. guided by a linear guide or recirculating ball bearings such that in an overload case, the cam roller can lift off the cam without causing damage.

At the retainer of Abtransporteinrichtung directed to the at least one upper removal roller sensor is provided, which can detect, for example, with an inductive initiator the bottom dead center of a lifting carriage of the upper removal roller. If bottom dead center is never reached during a singulation cycle, then there is an error.

The reasons for this are in relation to the thickness of the printed product too low set passage height, double trigger (two printed products are isolated together) or overload due to product jam in question.

A further embodiment of the invention provides protection of the push-off device against overload by comparing the effective torque curve of the drive of the push-off unit with an expected torque curve and immediately stopping the drive when the defined deviation is exceeded.

The restricted crank mechanism has a drive shaft with a crank disc mounted thereon. The crank pulley has an eccentric to the drive shaft arranged, the first axis and is rotatably coupled in this first axis with a first end of a connecting rod. A second end of the connecting rod is connected by means of a second axis rotatably connected to a first holder fixed to the Abschiebetisch. At Abschiebetisch each receiving a ball bush, second holder are arranged. At least two guide rods arranged parallel to one another and in a discharge direction of the printed products and fastened to a frame of the device serve as guide for the ball bushings.

Downstream of the magazine, a removal device, consisting of an upper and a lower removal roller and a retainer for located in the magazine printed products. Between the retainer and a bearing surface of the Abschiebetisches a first passage height and formed between the Abtransportwalzen a second passage height for the printed products, both passage heights are in particular fixedly coupled together.

The retainer can be adjusted to a first and the removal rollers to a second passage height. The task of the retainer is to retain the second lowest printed product in the magazine, while the lowermost printed product is transported from the Abschiebetisch in Ausförderrichtung. If the first passage height is set too small compared with the thickness of the printed products, it will happen to a product jam or damage to the printed products. If the first passage height is set too high, then the second lowest printed product can also be removed together with the lowest printed product. Particularly advantageous is the above-mentioned, fixed coupling of the first passage height with the second passage height, for example in the ratio 1.1 to 1.9. According to the invention, such a coupling is achieved by using two separate threaded spindles acting on the retainer or on the upper removal roller and thus on the first or second passage height. These thread pitches are designed differently or they have different drive wheels and thus different speeds. The direct coupling simplifies the setting during set-up, as there is no need for separate adjustment. This leads to time savings. The drive of the adjustment can be done manually or by means of adjustment. When using a separate servo motor, the first passage height can be changed dynamically during a pushing-out movement in such a way that a product thickness that differs, for example, from product samples over the product length is compensated. In this way, printed products with varying thicknesses can be separated without marking. Of course, not only the first but also the second passage height or also both passage heights can be changed together in accordance with the thickness of the respective printed products during the removal of the printed products.

In a further embodiment of the invention, the return stroke of the push-off table is designed so that simultaneously with the passing of the rear side of the lowermost printed product under the retainer and the driver of the push-off with its stop surface, the rear side of the second lowest printed product passes. In this way, a controlled slipping of the rest of the stack can be achieved. The printed products fall parallel to the support surface on the Abschiebetisch, which is particularly important for thick printed products. If, in such thick printed products, one-sided slipping occurs, the stacking movement becomes very uneasy and there is a risk that the printed products in the magazine will tilt and thus hinder the separation.

A next embodiment of the invention relates to the suppression of the singulation process during one or more work cycles, without reducing the speed of the push-off device and / or the removal device. With the device described above, the separation process can be adjusted according to need, so that no printed product is separated in at least one working cycle. In particular, it is provided to perform a return stroke movement with the drive of the push-off device after the transfer of a printed product to be separated, while the movement of the at least one pair of rollers is normally completed. The return stroke movement includes, in particular, a waiting position in an intermediate position, from which it is possible, if necessary, to return to the normal singling process. This shows the clear advantage of separately driven Abschiebe- and Abtransporteinrichtungen, which make it possible to decouple the start and stop movements of the two systems from each other. Thus, the Abschiebevorgang can be suppressed, for example, for two or more cycles. The most critical of all, however, is the suppression of a single stroke of work.

In a further embodiment of the invention, the controller is provided with information about the dimensions of the printed products to be separated, in particular their length and thickness, by means of an operating unit or by other data transmission. Then, the relevant adjustment axes are adjusted to the required dimensions by means of servomotors and / or there is a direct influence on the design of the motion profiles of Abschiebetisch and / or removal rollers taken. The corresponding input can be made by an operator, via a higher-level control or by sensing by sensors on the magazine itself. It is conceivable to record the dimensions of the printed products via sensors which are mounted directly in the magazine of the separating device.

Further advantageous features emerge from the dependent claims, the following description and the drawings.

Fig. 1

eine Seitendarstellung einer erfindungsgemässen Vereinzelungsvorrichtung im Schnitt durch die Mittelebene;

Fig. 2

eine perspektivische Darstellung einer Abtransporteinrichtung;

Fig. 3

eine perspektivische Darstellung eines Druckproduktes;

Fig. 4

eine gegenüber der Fig. 1 um 90° versetzte Draufsicht auf die erfindungsgemässe Vereinzelungsvorrichtung;

Fig. 5

ein Bewegungsdiagramm eines normalen Vereinzelungszyklus;

Fig. 6a

eine schematische Darstellung der Vereinzelungsvorrichtung zu Beginn eines Vereinzelungszyklus;

Fig. 6b

eine schematische Darstellung der Vereinzelungsvorrichtung während der Beschleunigungsphase des Abschiebetisches;

Fig. 6c

eine schematische Darstellung der Vereinzelungsvorrichtung beim Passieren der Vorderseite des untersten Druckproduktes an zumindest einem dem Abtransport dienenden Walzenpaar;

Fig. 6d

eine schematische Darstellung der Vereinzelungsvorrichtung bei der Übergabe des Druckproduktes von der Abschiebeeinrichtung auf die Abtransporteinrichtung;

Fig. 6e

eine schematische Darstellung der Vereinzelungsvorrichtung während des Abtransports des Druckproduktes durch die Abtransportwalzen;

Fig. 6f

eine schematische Darstellung der Vereinzelungsvorrichtung beim Erreichen der Ausgangsstellung.

The invention will be explained in more detail below with reference to the drawing, to which reference is made with respect to all details not mentioned in the description, using exemplary embodiments. In the drawing show:

Fig. 1

a side view of an inventive singulation device in section through the median plane;

Fig. 2

a perspective view of a Abtransporteinrichtung;

Fig. 3

a perspective view of a printed product;

Fig. 4

one opposite the Fig. 1 90 ° offset top view of the inventive separation device;

Fig. 5

a movement diagram of a normal separation cycle;

Fig. 6a

a schematic representation of the separating device at the beginning of a separating cycle;

Fig. 6b

a schematic representation of the separating device during the acceleration phase of the Abschiebetisches;

Fig. 6c

a schematic representation of the separating device when passing the front of the lowermost printed product on at least one pair of rollers serving for removal;

Fig. 6d

a schematic representation of the separating device in the transfer of the printed product from the removal device to the Abtransporteinrichtung;

Fig. 6e

a schematic representation of the separating device during the removal of the printed product by the removal rollers;

Fig. 6f

a schematic representation of the separating device when reaching the starting position.

In Fig. 1 is a separating device 1 for printed products 2, 2a, 2b, 2c ( Fig. 3 . Fig. 6a - 6f ), which consists essentially of a magazine 3, a removal device 4 and a push-off device 5, which in each case on a Frame 6 are attached. The frame 6 is, for example, a multiple-piece welding construction, but may also have screwed together joining parts or be a cast construction.

The push-off device 5 comprises a push-off table 7 and components which are required for its translatory oscillating movement. These include a drive shaft 8 with a crank disc 9 mounted thereon, which in turn is rotatably coupled to a first axis 10 with a first end 82 of a connecting rod 11. An opposite, second end 83 of the connecting rod 11 is connected by means of a second axis 12 rotatably connected to a first holder 13, which in turn is fixed to the Abschiebetisch 7. In order to achieve an oscillating translational movement of the push-off table 7 in a discharge direction 14, the push-off table 7 is connected to second holders 15, which in turn are equipped with ball bushings 16. At least two parallel to each other and arranged in Ausförderrichtung 14 and attached to the frame 6 guide rods 17 serve the ball bushings 16 as a guide. A Abschiebehub H of Abschiebetisches 7 is determined essentially by a crank radius R of the crank disk 9. By such, consisting of the drive shaft 8, crank 9 and connecting rod 11, the crankshaft 78, offset with respect to the orientation of the guide rod 17 arranged drive shaft 8, can be a simple and cost-effective way to realize a robust and wear-resistant deporting device 5. For mass balance and thus for the reduction of vibrations on the frame 6, an oscillating counterweight to the Abschiebetisch 7 can be installed. As an alternative to the limited crank drive 78, a crank loop may also be arranged.

For conveying the lowermost, to be separated printed product 2a ( Fig. 6a-f ) is at the Abschiebetisch 7 a driver 18 and / or 7 vacuum openings 19 are arranged in the Abschiebetisch. The driver 18 is dependent on a length A ( Fig. 3 ) of the printed products 2, 2a, 2b, 2c in the corresponding position on the Abschiebetisch 7 attached. An end-face abutment surface 20 of the driver 18 serves the positive entrainment of the lowermost printed product 2a. For improvement the process security when separating the printed products 2, 2a, 2b, 2c, the vertical dimension of the driver 18 of a thickness C of the printed products 2, 2a, 2b, 2c are adapted. The adjustment is usually done by using different height drivers 18. Another way to take the separated product to be separated 2, 2 a, 2 b, 2 c through the Abschiebetisch 7 represent the vacuum openings 19, which may be arranged alternatively or in addition to the driver 18. For this purpose, a quick-acting valve 79 is switched by a controller 21 so that from the beginning of a working stroke M ( Fig. 5 ) until shortly before reaching a transfer point 22 at which the respective printed product 2, 2a, 2b, 2c is transferred to two roller pairs of the removal device 4, consisting of an upper and a lower removal roller 23, 24, a vacuum chamber 25 arranged on the removal table 7 is evacuated via a supply line 81 by a vacuum source 80. Via the vacuum openings 19 connected to the vacuum chamber 25 in the Abschiebetisch 7 the underside of the lowermost printed product 2a is non-positively sucked to a support surface 26 of the Abschiebetisches 7. Of course, the vacuum can also be generated directly on the Abschiebetisch 7, for example by means of a non-illustrated, working with compressed air according to the Venturi principle injector. If necessary, the vacuum can be relatively quickly removed by additional application of compressed air. Alternatively, of course, only a single pair of rollers, consisting of an upper and a lower removal roller 23, 24 may be formed. Likewise, more than two pairs of rollers can be arranged.

The removal device 4 has a fixed to the frame 6 retainer 40 and the above-mentioned pairs of rollers whose lower removal rollers 24 are driven by a shaft 27, which in turn with in Fig. 2 shown bearings 28 is also attached to the frame 6. The removal rollers 23, 24 have on the periphery with advantage a rubberized surface, so that both the required contact pressure, as well as the required friction between the removal rollers 23, 24 and the surface of the respective printed product 2, 2a, 2b, 2c achieved become. Between the retainer 40 and the support surface 26 of the Abschiebetisches 7 a first passage height K is formed for the printed products.

The upper removal rollers 23 are driven by a shaft 29, which in turn is mounted in a lifting carriage 30. The lifting carriage 30 cooperates with a linear guide 31 fixed to the frame 6, which permits a vertical translation of the lifting carriage 30, i. perpendicular to the discharge direction 14 allows. In addition, a driven by a drive shaft 32 cam 33 is provided on the lifting carriage 30, on the circumference of which under the action of a spring 34 rolls a cam roller 35, wherein the spring 34 is directly connected to the lifting carriage 30. This arrangement results in a lift 1 for the upper removal rollers 23, the amount of which causes a second passage height L to fluctuate between the upper removal rollers 23 and the lower removal rollers 24 during one working cycle. The drive shaft 32 performs exactly one revolution per separation cycle, while the stroke I of the upper removal rollers 23, for example, 4-8 mm, which is sufficient to not injure a front side 36 of the respective printed product 2, 2a, 2b, 2c in its removal , The upper removal rollers 23 and the lower removal rollers 24 rotate in the Ausfördervorgang according to the direction of rotation arrows 37, 38 in the opposite direction.

The setting of the second passage height L to the corresponding thickness C of the respective printed product 2, 2 a, 2 b, 2 c takes place by the whole, from the upper removal rollers 23 with its shaft 29, the lifting slide 30 and the spring 34 existing assembly, on the the drive shaft 32 of the cam 33 is mounted, is displaced parallel to the linear guide 31 by means of a guide rod 39. The first passage height K represents the mass between the bearing surface 26 of the Abschiebetisches 7 and the non-designated lower edge of a likewise attached to the frame 6 retainer 40. On retainer 40 is designed as an inductive initiator sensor 41 is attached, which during the lifting movement of the upper removal rollers 23rd whose bottom dead center scans in order to detect an overload if necessary.

The drive shaft 8 of the push-off device 5 is connected to a rotary drive 42. The drive movement is transmitted by turning the drive shaft 8 to the crank disk 9 and from there via the connecting rod 11 and the holder 13 to the Abschiebetisch 7. Since both the drive shaft 8 of the push-off device 5 and the drive shaft 32 of the cam 33 have to perform one complete revolution per separating cycle, the latter is also connected to the drive 42 of the push-off device 5. Alternatively, the drive shaft 32 of the cam 33 can also be connected to a rotary drive 43 of Abtransporteinrichtung 4. The cam plate 33 arranged on the lifting carriage 30 is equipped with a drive 84 which is separate from the drive 42 of the push-off device 5 and the drive 43 of the removal device 4.

The drive 42 of the push-off device 5 is designed as a servomotor and equipped with a position feedback. Drives of this type are inexpensive. Thanks to the limited crank mechanism 78, the direction of rotation of the drive can always be maintained. As a result, such a rotary drive 42 has a greatly reduced heat dissipation compared with the linear motors used in the prior art. The drive 42 of the push-off device 5 is associated with a trained as a servo controller drive controller 44, which ensures that the drive 42, the predetermined, in this case non-uniform motion profile really departs. Alternatively, the drive 42 can also be designed as an asynchronous three-phase motor with position feedback.

The drive 43 of the removal device 4 is used directly for the movement of the upper and the lower removal rollers 23, 24 and is also designed as a servomotor with position feedback. Alternatively, the drive 43 can be designed as an asynchronous three-phase motor with position feedback. The motion transmission happens here in a known, not shown in detail. Analogous to the drive controller 44 of the push-off device 5, a drive controller 45 of the removal device 4 assumes the task of carrying out the predefined movement of the upper removal rollers 23 and the lower removal rollers 24 by means of the rotary drive 43. Essentially, it is about changing the conveying speed during the transport of the printed products 2, 2a, 2b, 2c, in particular to an increase in the conveying speed to Ausfördergeschwindigkeit. Alternatively, however, it is also conceivable that no speed change takes place or that the conveying speed is reduced.

The controller 21, which exchanges the required data for operating the separating device 1 with the drive controller 44 of the push-off device 5 and the drive controller 45 of the removal device 4, is provided in a higher-order manner. By means of an operating unit 46 settings of the separating device 1 can be displayed or changed.

Fig. 2 shows the essentially three subassemblies Abtransporteinrichtung 4. The first assembly includes the upper removal rollers 23, which, as already described, driven by the shaft 29 and stored in the lifting carriage 30. This module carries out a lifting and lowering movement per separating cycle and is drive-connected via a drive shaft 47, which is rotatably mounted at one end in a bearing 48. The bearing 48 is with the in Fig. 1 shown frame 6 connected.

The second assembly consists of a first bearing block 49, which takes over the bearing of the drive shaft 32 of the cam 33, a second bearing block 50 and a connector 51. This assembly is guided translationally by two guide rods 39 and is adjustable via a first threaded spindle 52 in height , By turning the threaded spindle 52, the second passage height L can be adjusted depending on the product. The drive shaft 32 is driven via a propeller shaft 53, which is rotatably mounted at one end in a likewise connected to the frame 6 storage 54.

The third assembly consists of the retainer 40, which is connected to a carrier 55. The translational guide is perceived by the two guide rods 39, wherein the adjustment takes place via a second threaded spindle 56. By turning the threaded spindle 56, the first passage height K can be adjusted depending on the product.

In order to achieve, for example, a fixed ratio between the first passage height K and the second passage height L, the threaded spindles 56 and 52 can each be equipped with a gear 57 or 58, the former at the same thread pitch of the threaded spindles 56, 52 a smaller number of Has teeth. As in Fig. 2 can be seen, the threaded spindles 56, 52 operated via an adjusting 59, which is mounted together with the threaded spindles 56, 52 in a third bearing block 60. About a connected to the adjusting 59 gear 61 whose rotation is transmitted to the gears 58, 57, which each move their threaded spindle 52, 56. The adjusting drive 59 can be formed for example as a motor or as a hand crank. As an alternative to a common adjusting drive 59, the second and the third assembly can also be designed to be independently adjustable.

Fig. 3 shows a printed product 2 with its on the Ausförderrichtung 14 related dimensions, ie with its length A, width B and thickness C in the discharge direction 14 leading the front side 36 of the printed product 2, while trailing a rear side 62 is formed. The printed product 2 may be, for example, a stapled magazine, a newspaper, a brochure, a hard-bound catalog, a supplement, a thread-stitched book or a printed sheet. In the case of this type of singulation, the product back is frequently arranged on the front side 36, ie transversely to the discharge direction 14, but may also be formed parallel to the discharge direction 14 or on the rear side 62 of the printed product 2.

Fig. 4 shows the separating device 1 in plan view, wherein the Abschiebetisch 7 with the driver 18 and the stop surface 20 are clearly visible. The magazine 3 consists essentially of discharge direction 14 left and right side stops 63, 64 front and a back stop 65, 66 and a magazine bottom 67. In format change, both the left and right side stop 63, 64, as well as the back stop 66 be reset. This setting of the magazine 3 can be done manually or automatically, the latter example, with actuators, not shown. Relative to the two side stops 63, 64, the vacuum openings 19 are advantageously in one middle region of the Abschiebetisches 7 and downstream in the discharge 14, ie arranged near the front stop 65. A sensor 68 mounted, for example, on the front stop 65 can be a distance measuring sensor which serves to determine the length A of the printed product 2, 2a, 2b, 2c and passes the measured value to the controller 21, whereupon the latter is sent to the drive controller 44 of the push-off device 5 and / or the drive controller 45 of the Abtransporteinrichtung 4 issued the command to perform a the length A of the printed product 2, 2a, 2b, 2c adapted motion profile.

In Fig. 5 the movement diagram of an exemplary singulation cycle is shown. The X axis represents this cycle from 0 ° to 360 °. The position of the push table 7 or its speed values are indicated on the Y axis, whereby the absolute values are not shown to scale. A movement profile 69 of the push-off table 7 indicates its lifting movement, with a turning point WP tending to lie later than 180 ° of the singling cycle. The point of inflection WP separates the working stroke M from a return stroke N. With a speed of the Abschiebetisches 7 representing, first curve 70 a 7 of the stroke movement of the Abschiebetisches 7 associated speed profile is shown. In contrast to a uniformly rotating, restricted crank mechanism, the maximum speed of the push-off table 7 according to the invention is achieved far beyond half of its Abschiebehubs H. The peripheral speed 71 of the removal rollers 23, 24 assumes the maximum speed of the Abschiebetisches 7 in a first phase and is in a second phase with advantage to a here assumed to be constant feed rate 72 of both in Fig. 1 as well as in Fig. 6f merely indicated following aggregates 73 of the separating device 1 accelerates. A second curve 74 representing the speed of the printed products 2, 2a, 2b, 2c shows that the printed product 2, 2a, 2b, 2c to be separated is first accelerated together with the push-off table 7 by positive and / or non-positive engagement it is detected at the transfer point 22 to the roller pairs formed by the upper and lower removal rollers 23, 24 at the same speed. As a result, the printed product 2, 2a, 2b, 2c further accelerated until the required feed rate 72 of the following unit 73 has been reached and the printed product 2, 2a, 2b, 2c leaves the separating device 1 at a delivery point 75 to the following unit 73. Due to the described two-phase acceleration of the respective printed product 2, 2a, 2b, 2c arise during its transfer from the removal device 5 to the Abtransporteinrichtung 4 no speed jumps, which on the one hand markings are prevented and on the other hand the possibility is created, the printed product 2, 2a, 2b, 2c gently to accelerate to the required, variable Ausfördergeschwindigkeit. In this way, a better cycle performance and improved process safety is achieved with gentle transport of the printed products advantageous.

The position of the delivery point 75 on the X-axis can vary with the length A of the printed product 2, 2a, 2b, 2c. Shorter printed products 2, 2 a, 2 b, 2 c result in a shorter engagement of the removal device 4, which leads to a greater acceleration in the case of following units 73 with a clock-bonded sequence and fixed division. As a result, the delivery point 75 to the follower unit 73 is shorter on the X-axis for shorter print products 2, 2a, 2b, 2c, while longer print products 2, 2a, 2b, 2c can be accelerated more gently. Accordingly, the acceleration phase can also be adapted to the format. For this purpose, the controller 21 triggers a corresponding change in the peripheral speed of the removal rollers 23, 24.

With a movement profile 76, the movement of the upper removal rollers 23 is shown, which are lowered towards the transfer point 22 to the pairs of rollers and raised again at the latest shortly before the end of the separation cycle to the Abschiebehub H. The control of the quick-change valve 79 for the evacuation of the vacuum openings 19 is in Fig. 5 not explicitly shown, but has already been described previously.

Fig. 6a Simplifies the situation at the beginning of a singulation cycle, what in Fig. 5 corresponds to the position at 0 ° on the X-axis. The lowest, to be singled Printed product 2a is still in the same position as a second lowermost printed product 2b and a subsequent printed product 2c of a stack 77, while the upper removal rollers 23 are in the raised position.

Fig. 6b During the acceleration phase, the lowermost printing product 2a to be separated from the stack 77 points to the maximum speed of the push-off table 7 as a result of the engagement of its driver 18. The second lowermost printed product 2b, the next printed product 2c and all other printed products of the stack 77 are picked up by the retainer 40 the co-promotion prevented. The driver 18 prevents it at the same time early tilting of the rest of the stack. The upper removal rollers 23 are still in the raised position.

Fig. 6c refers to the time at which the front side 36 of the lowermost, to be separated printed product 2a reaches the plane of the upper and lower removal rollers 23, 24. In this situation, the printed product 2a is still conveyed by the driver 18 of the push-off table 7 and the upper removal rollers 23 are still not engaged with the printed product 2a. Too early engagement of the pairs of rollers may lead to damage or deterioration of the quality of the printed product 2a by damaging its front side 36, which in particular represents a tack-bonded spine.

Fig. 6d represents the transfer of the printed product 2a of the removal device 5 to the Abtransporteinrichtung 4, ie the in the Fig. 5 shown transfer point 22. The upper removal rollers 23 are now lowered to the printed product 2a and thus engaged. For a short moment, the printed product 2a is transported both by the Abschiebetisch 7, ie by its driver 18, as well as by the pairs of rollers.

Fig. 6e shows the situation during the Ausfördervorgangs the printed product 2a through the pairs of rollers, while the Abschiebetisch 7 and its driver 18 are in the return stroke N.

In Fig. 6f is the discharged printed product 2a to see, which was passed to the following unit 73. The Abschiebetisch 7 has now reached its original position again and is ready to singulate the former second lowest printed product 2b. At the latest at this point in time, the remaining stack has slid so far that the underside of this printed product 2b makes contact with the push-off table 7. Advantageously, the driver 18 releases the slippage of the remaining stack at the same time as the printed product 2a leaves the magazine 3. In this way, a parallel slipping is possible and prevents tilting of the printed products of the rest of the stack. The upper removal rollers 23 have arrived again in their raised position. Another singulation cycle can begin.

Claims (18)

1. Method of separating printed products from a stack (77), in which the printed products (2, 2a, 2b, 2c) are transferred by a pushing device (5) separating them from the stack (77) to a downstream removing device (4) conveying away the separated printed products (2, 2a, 2b, 2c), the pushing device (5) and the removing device (4) being driven in rotation independently of one another, characterised in that the printed products (2, 2a, 2b, 2c) are accelerated in the pushing device (5) to a first speed and in the removing device (4) to a second speed that is higher than the first speed, the pushing device (5) and the removing device (4) being controlled in such a manner that there are no significant changes in speed when the printed products (2, 2a, 2b, 2c) are transferred from the pushing device (5) to the removing device (4).
2. Method according to claim 1, characterised in that the pushing device (5) is controlled in such a manner that it reaches a maximum speed after the midpoint of its pushing stroke (H).
3. Method according to claim 1 or claim 2, characterised in that the separation of printed products (2, 2a, 2b, 2c) from the stack (77) is suppressed for at least one work cycle without reducing the first and/or the second speed.
4. Method according to one of claims 1 to 3, characterised in that the pushing device (5) comprises at least one vacuum opening (19) and a quick-acting valve (79) associated therewith and that the quick-acting valve (79) is controlled in such a manner that it separates the vacuum opening (19) from a vacuum source (80) in a synchronised manner before the printed product (2, 2a, 2b, 2c) is transferred from the pushing device (5) to the removing device (4),
5. Method according to one of claims 1 to 4, characterised in that the removing device (4) is controlled in such a manner that the second speed is changed during the transportation of the printed product (2, 2a, 2b, 2c) and, in particular, is increased until a feed speed (72) of a downstream unit (73) is reached.
6. Method according to claim 5, characterised in that the feed speed (72) of the downstream unit (73) is changed in a variable manner.
7. Method according to one of claims 1 to 6, characterised in that the pushing device (5) and the removing device (4) each comprise their own drive (42, 43), wherein an actual torque characteristic for the drive (42) of the pushing device (5) is determined, the result of this determination is compared with an expected torque characteristic and the drive (42) of the pushing device (5) is stopped if the result exceeds a previously defined deviation from the expected characteristic.
8. Method according to claim 7, characterised in that the drives (42, 43) are driven with an irregular rotary motion.
9. Method according to one of claims 1 to 8, characterised in that the pushing device (5) executes a return movement after a printed product (2, 2a, 2b, 2c) to be separated has been transferred to the removing device (4).
10. Method according to claim 9, characterised in that the return movement of the pushing device (5) includes a holding point in an intermediate position from where it can be returned to the separating process if necessary.
11. Method according to one of claims 1 to 10, characterised in that the removing device (4) comprises at least one roll pair consisting of an upper and a lower removing roll (23, 24) and that the upper removing roll (23) is moved up and down by one stroke once during each separating cycle.
12. Method according to one of claims 1 to 11, characterised in that the pushing device (5) comprises a push table (7) with a pusher (18) and the removing device (4) comprises a retainer (40) for the printed products (2, 2a, 2b, 2c) situated in the stack (77) and that, at the same time as a rear side (62) of an upstream printed product (2, 2a, 2b, 2c) passes below the retainer (40), the pusher (18) also moves past a rear side (62) of a downstream printed product (2, 2a, 2b, 2c) by means of a stop surface (20).
13. Method according to claim 12, characterised in that a first clearance height (K) for the printed products (2, 2a, 2b, 2c) is provided between the retainer (40) and a bearing surface (26) of the push table (7) and a second clearance height (L) is provided between the removing rolls (23, 24) and that the first clearance height (K) and/or the second clearance height (L) is changed during the removal of the printed products (2, 2a, 2b, 2c).
14. Method according to one of claims 11 to 13, characterised in that the upper removing roll (23) is moved back up into an initial position before a printed product (2, 2a, 2b, 2c) downstream of the previously separated printed product (2, 2a, 2b, 2c) reaches the roll pair.
15. Method according to one of claims 11 to 14, characterised in that the upper removing roll (23) is arranged on a shaft (29) supported in a lifting carriage (30), the lifting carriage (30) is vertically movable on a frame (6) and the lifting carriage (30) is provided with a cam disc (33) driven by a drive shaft (32) and off the circumference of which a cam roller (35) rolls under the influence of a spring (34) directly connected to the lifting carriage (30), the cam disc (33) being driven independently of the pushing device (5) and the removing device (4).
16. Method according to one of claims 11 to 15, characterised in that the removing device (4) comprises a first threaded spindle (52) acting on the upper removing roll (23) and a second threaded spindle (56) acting on the retainer (40), that information about the dimensions of the printed products (2, 2a, 2b, 2c) to be separated, in particular about the length (A) and thickness (C) thereof, is fed to a control unit (21) of the pushing device (5) and the removing device (4) by means of an operating unit (46) or by another data transmission method and that, in accordance with this information, positioning axes of the first and second threaded spindles (52, 56) are adjusted by means of a positioning drive (59) and/or direct influence is exerted on the configuration of motion profiles of the pushing device (5) and the removing device (4).
17. Method according to one of claims 11 to 16, characterised in that a circumferential speed (71) of the removing rolls (23, 24) is adapted as a function of the length (A) of the printed products (2, 2a, 2b, 2c).
18. Method according to one of claims 11 to 17, characterised in that a circumferential speed (71) of the removing rolls (23, 24) is accelerated in a first phase to a maximum speed of the push table (7) and in a second phase to a feed speed (72) of a downstream unit (73).

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