Patent Application
20090309289
This application claims the priority of European patent Application No. 08405156.4, filed on Jun. 12, 2008, the subject matter of which is incorporated herein by reference.
The invention relates to an apparatus for removing flat printed products from a stack and transferring the printed products to a moving transporting device. Such an apparatus including a separating device for separating out and removing the printed products from the stack, as well as a rotating conveyor for taking over the separated printed products and supplying them to the transporting device, wherein the conveyor has an axis of rotation and at least one gripper for taking over the printed products in a gripping plane. Further, the transporting device has a transporting direction and a vertical center plane that extends in the transporting direction, and wherein the rotational axis is oriented at least approximately at a right angle to the center plane. The invention furthermore relates to a corresponding method for the removal of flat printed products from a stack and for transferring the printed products to a moving transporting device.
A rotary feeder is disclosed in Swiss patent document CH 617905 A5, which is designed to pull flat printed products with off-center folds individually from a stack inside a hopper, to open up these printed products, and to deposit them on the gathering chain of a gathering and wire-stitching machine. The printed products, which are separated with the aid of a suction device, are gripped successively by a continuously rotating draw-off drum provided with a gripper and are accelerated to the drum speed. The movement direction for the printed products is reversed at an end stop for the sheets. The printed products are subsequently opened up with the aid of two counter-rotating drums that are also provided with grippers. The first opening drum in this case grips the first leg of the respective printed product, provided with an overlay fold, while the second opening drum grips its shorter leg. The sheets are subsequently deposited by dropping them at a 90° angle relative to the transporting direction of the gathering chain. In the process, the printed products are in free fall for a short distance, until the respective inside of a printed product impacts with the saddle of the gathering chain or comes to rest on the back of previously gathered printed products. The printed products are accelerated to the transporting speed of the gathering chain when coming in contact with the pusher on the gathering chain.
Under this approach, the printed products are strongly accelerated while being gripped by the draw-off drum. The subsequent change in direction at the end stop causes a deceleration and then a renewed acceleration of the printed products, which requires additional processing time and can lead to undesirable markings on the printed products or deformation of the printed products. Since the printed products are not accelerated to the chain speed prior to being dropped onto the gathering chain, the pushers on the gathering chain impact at a high speed with the deposited printed products. The printed products can thus be pushed together with enough force, so that their reliable acceleration through the pushers is no longer ensured and the end position of the respective printed product relative to the previously gathered printed products and/or the pusher can greatly vary. This can result in a reduction of the quality of the end product and can cause process interruptions and thus a reduced production capacity. Finally, the dropping of the sheets during the free fall is uncontrolled and is furthermore influenced by the surface-related mass of the printed products, the side dimensions, the structure, the production speed and the format for the printed products. A relatively large chain pitch, meaning a long distance between the pushers, is therefore required to ensure nonetheless that the printed products are dropped between two successively following pushers onto the gathering chain. The chain speed must therefore be increased while the cycle time is maintained, which further complicates the processing and can lead to problems with the quality.
European patent document EP 1024099 A1 discloses an apparatus for opening and depositing a folded, flat printed product on a moving transporting device of a high-performance machine, operating at a processing speed of more than 16000 printed products per hour. The printed products can be pre-accelerated in this machine through additionally installed acceleration drums or rolls, up to the speed of the transporting device, thus making it possible to drop the product, at least in part, in the movement direction of the transporting device.
However, this solution cannot remove the disadvantage of the relatively high dropping distance and the connected, undefined free fall of the printed products. To be able to achieve high production capacities with a corresponding process safety, the printed products must be separated with the highest possible definition and must be opened, conveyed, and transferred to the transporting device.
Swiss patent document CH 695052 A5 relates to an apparatus for removing flat printed products from a plurality of stacks and for gathering the printed products along a gathering section, consisting of a transporting device and a plurality of conveyors, wherein the conveyors function to supply the printed products to the transporting device. This type of machine, which differs from the aforementioned prior art, is a so-called gathering machine and can be connected to a downstream-arranged adhesive binding machine. An opening of the printed products is neither intended nor necessary in this case. The rotational axes of the conveyors for this solution are respectively arranged at a right angle to a vertical center plane for the transporting device that extends in transporting direction of the transporting device, so that the printed products are respectively dropped in the transporting direction onto the transporting device, wherein the printed products are initially stacked one above the other. The respectively lowest printed product is partially separated from the stack with the aid of a separating device in the form of suction cups or the like, is then gripped by grippers arranged on the respective conveyor drum, is pulled completely from the stack and is conveyed to the transporting device. The conveying device is thus formed by the surface of the respective drum and the grippers that operate jointly with this drum.
A gripper plane that extends parallel to the rotational axis for the conveyor and thus at a right angle to the center plane for the transporting device is embodied between the drum surface and the grippers. This gripper plane corresponds to the contact surface of the drum and the gripper, without a printed product disposed in-between, and corresponds to the location where the grippers take over the printed products from the separating device.
However, the inherent weight of the stack composed of printed products increases with increasing stack height, which can result in problems with the separation. Stack compartments of this type therefore have a height limit and can only be used to a limited degree as buffer storage for upstream-installed feeding devices, such as roller systems. In addition, this solution cannot be used for processing the so-called bundles, meaning intermediate products composed of a plurality of side-by-side stacked, upright and strapped products, without expensive additional devices. Furthermore, it is extremely difficult to process stiff printed products with this technology because of the required rotation around the drum.
It is therefore an object of the present invention to provide a simplified apparatus and a corresponding method for removing folded printed products from a stack and depositing these on a moving transporting device, which apparatus removes the aforementioned disadvantages and/or combines the known advantages of gathering and stitching machines and collating machines. In particular, the goal is to improve the process safety, the quality of the final products and the production capacity, to avoid problems with the separation, and to allow a simple yet sufficient buffer storage of printed products.
The above and other objects are accomplished according to one aspect of the invention wherein there is provided an apparatus for withdrawing flat printed products from a stack and transporting the printed products, comprising: a transporting device having a transporting direction and a vertical center plane that extends in the transporting direction; a separating device to separate out the printed products from the stack; and a rotating conveyor having a rotational axis and a conveying direction, the rotating conveyor including at least one gripper with a gripper plane to grip a separated printed product in the gripper plane and supply the separated printed product to the transporting device, wherein the rotational axis is oriented approximately at a right angle to the center plane of the transporting device, and the gripper plane of the at least one gripper is essentially arranged in the center plane of the transporting device.
As a result of the invention, the printed products are essentially taken over by the rotating conveyor, conveyed and transferred to the transporting device in the center plane for the transporting device.
As a result, the required number of transfer locations for the printed products and the resulting process risks can be noticeably reduced. The change of direction during the conveying operation, as well as the connected deceleration and renewed acceleration of the printed products are consequently also omitted. A relatively low drop height can be realized as a result of a tangential approach of the conveyor to the transporting device, thus advantageously resulting in a compact apparatus including a continuously operating conveyor. Access to the individual structural components is furthermore improved and the process sequence can be tracked and monitored more easily by the machine operator. As a result of the embodiment of grippers with the defined gripper plane for and the corresponding orientation of the printed products, the stack alignment is essentially horizontal from the start, or at least need not be vertical. A hopper suitable for the buffer storage of the printed products can thus be used advantageously, wherein the hopper can also accommodate bundles composed of printed products. Finally, the speed of the printed products relative to the speed of the transporting device can be reduced optionally at the instant of dropping the sheet or signature. Since a deformation of the printed products is not required for the product takeover, as is required for the known withdrawing or opening drums, the printed products remain in a substantially extended position while passing through the device according to the embodiment, so that stiff printed products can be processed as well.
In another embodiment, at least one supply device for supplying the printed products is arranged in the region upstream of a takeover location, arranged between the separating device and the conveyor. The supply device supplies the printed products to the gripper with at least one edge oriented substantially in the gripper plane. The at least one supply device is embodied as a hopper that accommodates the stack, is provided with an end stop as well as the separating device and is arranged adjacent to the conveyor, or it is embodied as a feeding device for the printed products that are arranged between the separating device and the conveyor. Before reaching the takeover location, the printed products are oriented with at least one edge essentially in the gripper plane for the at least one gripper. Following the separation, they are either taken over directly at the takeover location, or they are first supplied to the takeover location.
In yet another embodiment, the option of either taking over the printed products directly or alternatively using the feeding device in-between makes it possible to advantageously adapt the apparatus and method to the respective process requirements.
According to a further embodiment, a sheet opener is installed between the separating device and the transporting device. The printed products can thus be opened during the feeding or conveying operation and can also be opened and transferred in the opened state to the transporting device, either in the same plane used for the takeover, conveying and transfer, or in an upstream positioned plane that is arranged at an angle thereto. An embodiment employing the invention can therefore advantageously be used even for devices having a saddle-shaped gathering chain, such as a gathering and stitching machines, thread-stitching devices, or the like.
In another embodiment, the conveyor is equipped with a driven rotor having at least one rotor arm. A gripper with a pair of gripper elements for gripping the printed products is arranged on each rotor arm, wherein at least one gripper element of each pair is embodied to be movable. The at least one gripper is attached to a support lever with a first and a second lever end, wherein the first lever end is connected via a joint to a rotor arm and wherein a cam roller for a control cam that is arranged on an apparatus frame is positioned on the second lever end. A defined control of the gripper position is thus possible during its rotation around the axis of rotation for the rotor, which allows a parallel orientation to the printed product to be taken over and/or to the transporting direction of the transporting device during the takeover as well as the transfer of the printed products.
According to a further embodiment, the conveyor is provided with a separate drive motor, in particular a servo-motor, such that it can advantageously be operated independent of the downstream-arranged transporting device and its operating speed can be varied, depending on the upstream and/or the downstream arranged devices.
In one embodiment, the at least one gripper is connected to a control element arranged on the support lever for the gripper elements. As a result, the gripper can be activated directly and individual printed products can be gripped purposely. The direct activation of the gripper furthermore allows an individual adaptation of the closing and opening moments.
In another embodiment, a measuring device for measuring the thickness of the printed products is advantageously arranged on the at least one gripper. This measuring device can be used to determine whether the gripper has gripped a single printed product, a plurality of printed products, or no printed product at all. In the event of a processing error, the partial processes that follow can be stopped and the amount of waste material reduced. If a plurality of printed products have been gripped impermissibly, these can be removed during a later partial process.
In yet another embodiment, the sheet opener is arranged in the region of the conveyor, immediately following the separating device in the conveying direction, and is provided with an opening device as well as a guide element arranged downstream in the conveying direction of the printed products. The opening device comprises a pivoting blade and the guide element is embodied in the shape of a sickle, thus making it possible to open the printed products during the conveying, without any additional acceleration or delay. The fact that the blade takes up the overlay fold along the front permits a secure opening of even small overlay fold lengths, thereby resulting in improved process safety as compared to the prior art.
In a further embodiment, at least one printing head and/or at least one glue-application head is arranged in the region of the guide element and/or the feeding device. The printed products can thus be provided with additional information during the conveying and/or the feeding operation and/or can be attached with glue to printed products already positioned on the transporting device.
In one embodiment, the guide element further comprises an intake part and a discharge part, which are embodied adjustable relative to each other, thereby making it easier to adjust the format adjustment depending on the printed products to be processed.
In another embodiment, following the removal from the stack, meaning after the separation, the printed products are taken over by a rotating gripper and are released from this gripper for the transfer to the transporting device, wherein the respective gripper is oriented parallel to the stack and/or the transporting device even before the takeover as well as the transfer of a printed product, and wherein this orientation is maintained until after the takeover and/or the transfer of the printed product. The respective printed product can thus be removed by the gripper essentially parallel to the stack and can also be transferred essentially parallel to the transporting device, resulting in a relatively quiet material flow where the printed products are transferred to the conveyor with defined control. The transporting device can be realized with smaller chain pitches, which results in a reduction of the transporting speed while simultaneously maintaining the same production capacity, thereby contributing to improving the process safety.
The present invention will be more readily understood from the following detailed description when read in conjunction with the accompanying drawings, in which:
The feeder 2 that is supported by a frame 9 comprises a hopper 10, a separating device 11, a sheet opener 12, and a rotating conveyor 13 for the printed products 4. The hopper 10 and the separating device 11 are arranged above the conveyor 13, meaning directly adjacent thereto in the frame 9. The sheet opener 12 can be omitted if the printed products 4 do not have to be opened for the processing steps following the transporting device 1.
The hopper 10 comprises two sheet metal side panels 14, 15, a bottom panel 16, as well as an end stop 17 for forming a stack 19 with the printed products 4, which are respectively taken over with the edge 18 that is embodied as a back pointing in downward direction.
A bottom and/or a side clearance space 20, 21 is embodied between the end stop 17 and the bottom panel 16 on the bottom, as well as between the end stop 17 and the side panel 15, wherein these clearance spaces are designed to aid the withdrawal from the stack 19 of the separated printed products 4. Sensors 22 and 23 are attached to the end stop 17 and the side panel 15, wherein one sensor is directed toward the lower clearance space 20 while the other sensor is directed toward the side clearance space 21. The hopper 10 is arranged at an angle in the frame 9, meaning it is arranged at an angle α that opens up in the direction of the side clearance space 21, relative to the ridge 8 of the transporting device 1, resulting in a defined and also slanted positioning of the printed products 4 on the side panel 14, regardless of the format. Of course, it is also possible to use only a single side panel. The hopper 10 can furthermore be arranged horizontal inside the frame 9, meaning parallel to the transporting device 1, wherein the positioning of the printed products 4 in that case is realized with a corresponding adjustment of the side panels 14, 15 of the hopper 10.
The separating device 11 is arranged in the lower clearance space 20 of the hopper 10 and is provided with a number of suction devices 24, as well as separating needles that are not shown herein.
The sheet opener 12, arranged in conveying direction 25 of the printed products 4 between the hopper 10 and the transporting device 1 and immediately following the separating device 11, is connected via a first fastening element 26 to the hopper 10 and via a second fastening element 27, shown in
The sheet opener 12 consists of an opening device 29 and a following, two-part guide element 30 in the shape of a sickle. As shown in
According to
The conveyor 13, which is shown in further detail in
The axis of rotation 50 for the conveyor 13 is arranged horizontal and at a right angle to the transporting direction 6 of the transporting device 1, as well as simultaneously also parallel to the orientation of the stack 19 and thus at a right angle to the end stop 17 on the hopper 10. Of course, the axis of rotation 50 for the conveyor 13 can also deviate somewhat from the right-angle position relative to the transporting direction 6 of the transporting device 1, which advantageously provides more freedom for embodying the conveyor 13.
A drive motor 53 is arranged on the frame 9, offset to the side of the drive shaft 51, which can be embodied as stepping motor, servo motor, or torque motor and permits a uniform as well as a non-uniform rotational movement of the conveyor 13 (
The drive motor 53 is provided with a first toothed belt wheel 54 while the drive shaft 51 is provided with a second toothed belt wheel that is not shown herein. A toothed belt 55 moves around both toothed belt wheels and drives the rotor 47.
The grippers 49 are respectively provided with a pair of gripper elements 56 (shown in
The grippers 49 are respectively positioned on a support lever 60, which is attached with a first lever end 61 via a joint 62 to the respective rotor arm 48 and which supports on a second lever end 63 a cam roller 65 that is forcibly guided inside a control curve 64 (
For each gripper element 56, the control element 66 is provided with a pneumatic cylinder that is not shown herein. Of course, the control element 66 can also be operated differently, for example hydraulically or electrically. The gripper movement is triggered by the control element 66, based on variables specified by the machine control unit. For example, a faulty withdrawal or a double withdrawal by the upstream-arranged feeders 2 can result in suppressing the gripper movement.
During the operation of the feeder 2, the printed product 4 that rests with its back, meaning the downward pointing edge 18, against the end stop 17 and the side panel 14 is initially lifted with the aid of the separating device 11, meaning the suction device 24 and the non-depicted separating needles, off the following printed product 4 in the stack 19 in the region of the lower clearance space 20 and is then moved to the gripper plane 58 of a gripper 49, which moves in the movement direction of the printed product 4. Following this, the printed product 4 is gripped along this edge 18 by the gripper elements 56. Of course, a different edge such as a side edge can also be gripped, depending on how the printed product 4 is supplied.
A separated out printed product 4 is then guided with the aid of the rotor 47 that rotates in the conveying direction 25 in a clockwise direction over the opening blade 32, which lifts the leg 45 with the overlay fold 3 slightly off the other leg 46 of the printed product 4. Depending on whether the printed products 4 to be processed are provided with a pre-fold or an overlay fold 3 embodied as a binding flap and before starting the processing for the respective work order, the blade 32 is pivoted with the aid of the pivoting drive 35 around the axis of rotation 34, so that it comes in contact with the corresponding leg 45, 46 of the printed product 4.
The position of the blade 32 is either adjusted manually or selected with the aid of a motor, wherein the required position can also be adjusted automatically. In the latter case, the sensors 40 arranged on the opening device 29 monitor the position of the legs, to ensure that a leg 45 is present in front and a leg 46 is present behind the guide element 30. If that is not the case, it is assumed that the printed product 4 is not opened and has an overlay fold 3 embodied on the other leg. The position of the blade 32 is then automatically adapted via the pivoting drive 35, activated by the machine control, to ensure a correct opening of the following printed product 4.
An automatic format adaptation is furthermore possible for each work order by initially determining the back length of a printed product 4 with the sensor 22, arranged above the end stop 17, and then the leg length of the printed product, meaning its format, via the sensor 23 that is arranged on the side panel 15 for the hopper 10. Accordingly, the distance between the sheet opener 12 and the printed products 4 is adapted with the first adjustment device 28, wherein simultaneously the intake portion 36 of the guide element 30 is displaced telescopically relative to the discharge portion 37. A corresponding displacement of the side panels 14, 15 for the hopper 10 occurs with the aid of the second adjustment device, which is not shown herein.
The rotor 47, which continues to rotate, conveys the opened printed product 4 that is pulled from the stack 19 in a vertical center plane 59, which is positioned in the drawing plane of
While following the control curve 64, the cam rollers 65 and thus also the grippers 49 attached thereto move along an essentially circular movement path around the axis of rotation 50. However, in the region ranging from immediately before to immediately after a takeover location 68 for the printed products 4 from the hopper 10, as well as in the region extending from immediately before to immediately after the transfer location 69 for transferring the printed products 4 to the transporting device 1, a movement in the conveying direction or counter to the conveying direction 25 is superimposed onto the grippers 49 by the correspondingly embodied control cam 64, via the joint 62, so that the grippers 49 respectively experience a corresponding movement relative to the rotation of the rotor 47 and/or the rotor arms 48. In these regions the grippers 49 are consequently oriented parallel to the hopper 10 and/or the ridge 8 of the transporting device 1. At the takeover location 68 for the printed products 4, the gripper elements 56 are closed with the aid of the control element 66 and are opened again at the transfer location 69. The takeover by the grippers 49 of the conveyor 13, the transport as well as the transfer of the printed products 4 are realized in a continuous movement, meaning without change in direction. In the transporting direction 6 of the transporting device 1, the printed products 4 are deposited at approximately at the same speed as the speed of the transporting device 1. The printed products 4 are therefore not only conveyed in the center plane 59 of the transporting device 1, but are also opened and deposited onto the transporting device 1 in this plane. The center plane 59 can therefore also be called the working plane.
As an alternative to the blade 32, which is stopped during the opening of the printed products 4, it is also possible to arrange gripper elements that are not shown herein above a specific section of the guide element 30. Such gripper elements may move along with the respective gripper 49 and are operated with the aid of a crank drive that is also not shown herein.
Additional and identically embodied feeders 2 can be installed before and/or after the feeder 2, so that a plurality of printed products 4 can be collected and stacked one above the other on the transporting device 1 and can be made available for a subsequent further processing, for example for the stitching in a wire-stitching or thread-stitching device not shown herein. To prevent the depositing of perfect printed products 4 on top of a previously deposited, imperfect product on the transporting device, it is possible to suppress the opening of the gripper 49 at the transfer location 69. The gripper 49 continues to hold the respective printed product 4, which is moved past the hopper 10 during a further rotation of the conveyor 13 and is deposited only then on the transporting device 1 and/or on a printed product previously deposited on the transporting device and recognized as perfect. In this way, it is possible to react shortly after detecting the imperfect product and to prevent further paper waste.
With the aid of one or more additional feeders, other flat materials such as DVDs, CD sleeves, product samples or the like can also be supplied alternatively to the printed products 4. In that case, two glue-application heads 43′ can be arranged on the support arms 42, 44 in place of the printing heads 43, which are connected to a corresponding glue supply line. Following the essentially identical operation of separating and withdrawing of the flat materials from the stack 19, glue is supplied to the surfaces of these flat materials during the conveying with the conveyor 13, meaning while they are clamped into the grippers 49, and they are subsequently glued together with a printed product 4 that is already located on the transporting device 1, wherein pressing rollers or brushes, not shown herein, are used to attach the flat materials provided with glue.
The frame 9′ and thus also the hopper 10′ and the separating device 11′ are arranged offset to the side and at an angle to the frame 9 for the conveyor 13, such that sufficient space remains next to the feeder 2′ for the transporting device 1 as well as adjacent feeders 2′. A second vertical plane 59′ is thus created, which is oriented at an angle to the center plane 59 of the transporting device. Since the separating and feeding of the printed products 4 to the center plane 59 takes place in the second plane 59′, the second plane 59′ can be referred to as the feeding plane. To connect the structural components of the feeder 2′ which are arranged in both planes 59, 59′, the transport belts 70 of the feeding device 71 respectively have an angled section 72. Additional printing heads or glue application heads 43, 43′ can be arranged in the region for the feed device 71, either in place of or in addition to the printing heads/glue application heads 43, 43′ installed in the region of the guide element 30. The additional components of the feeder 2′ are embodied and arranged identically to the first embodiment.
The mode of operation of the feeder 2′ essentially corresponds to the mode of operation of the feeder 2 of the first embodiment. As a result of the spatially separate arrangement of the separating device for the following conveying, opening, and depositing operations, additional processing options can advantageously be realized during an intermediate feeding step, such as applying inscriptions and adhesive, folding or positioning the printed products 4 that are supplied to the conveyor 13, but also the inserting or gluing on of additional printed products or other flat items.
Alternatively, the opening of the printed products could also occur upstream of the feeding device. In that case, which is not shown herein, a corresponding sheet opener is arranged upstream of the takeover location 68. The opening of the products is furthermore easier because the printed products are transported linear in this region, as compared to a rotational transport.
In the first embodiment, the hopper 10 that is positioned adjacent to the conveyor 13 is designed to hold the stack 19 and is provided with the end stop 17 and the separating device 11. In the second embodiment, the feeding device 71 that is arranged between the separating device 11 and the conveyor 13 is provided as the device 73, 73′ for supplying the printed products 4, wherein the printed products 4 are essentially supplied with the edge 18 extending in the gripper plane 58 for the grippers 49. Thus, in the first embodiment, a printed product 4 may be immediately gripped by the rotating conveyor 13 at a takeover location 68 proximate to the stack and, in the second embodiment, the printed product 4 may be supplied to a distal takeover location (see
It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 08405156.4 | Jun 2008 | EP | regional |
