Blank joining module with registration control

Abstract

The invention relates to a blank joining module for a conversion machine. The blank joining module comprises an upper feeder arrangement configured to feed and transport an upper blank (2b) and a lower blank (2a) towards a joining point (J) at which the upper blank overlaps the lower blank. The blank joining module includes a registration control system including a sensing system and a position correction device (86) configured to displace the upper blank to align with the lower blank.

Description

Technical Field

[0001] The present invention relates to a converting machine for producing paper and paperboard containers, such as folding boxes. In particular, the present invention relates to a blank joining module configured to join two blanks prior to folding the blanks together. Background Art

[0002] Converting machines, such as folder-gluers, are used in the production of packaging items such as paperboard and cartons. These machines consist of multiple workstations that fold and glue blanks to form boxes, which are then counted, stacked, and collated into batches.

[0003] Folder-gluers can be configured to produce many different types of packaging containers and folding boxes. One type of box, consisting of two joined blanks, is often called a "shelf-ready" box. A shelf-ready box consists of an outer box and an inner box that are glued together. The inner box serves as a container for the items to be stored, while the outer box protects them during transport. This type of box is often used in supermarkets and stores, where the inner box is placed on the shelf while the items remain inside.

[0004] When producing a box with several blanks connected together, a blank joining module with a double feeder is needed. Specifically, the first blank and the second blank each require a dedicated feeder.

[0005] An example of a blank joining module is described in document EP 2 072 241. Since the composed box is an assembly of two different blanks, it is necessary to ensure that the blanks are correctly aligned before joining together.

[0006] In order to control the alignment, the blank joining module in EP2072241 comprises upper and lower clamping belts provided with supports to control the positions of the first blank and the second blank.

[0007] US2002077236 discloses an alignment device configured to align an insert sheet and a blank relative to each other. The insert sheet is transported along a separate transport path until the insert sheet and the blank are joined together.

[0008] Alignment is achieved by detecting the position of each blank and insert sheet. The insert sheet is then shifted to advance or delay its arrival, bringing it into alignment with the blank. This shift is provided by a conveyor belt that is configured to accelerate or decelerate each insert sheet, depending on whether it arrives at the sensor early or late. Summary of the Invention

[0009] In view of the prior art, it is an object of the present invention to provide a register control system that is configured to provide accurate register correction while maintaining high production speeds.

[0010] This object is achieved by a blank joining module according to claim 1 .

[0011] According to a first aspect of the present invention, there is provided a blank joining module comprising an upper feeder device configured to supply an upper blank, a lower feeder device configured to supply a lower blank, and an upper conveyor system configured to transport the upper blank from the upper feeder device and a lower conveyor system configured to transport the lower blank from the lower feeder device, the upper conveyor system and the lower conveyor system being configured to transport the upper blank and the lower blank toward a joining point where the upper blank is positioned on the lower blank;

[0012] The blank joining module includes a register control device, which includes a sensing system and a position correction device. The sensing system includes an upper conveying sensor configured to detect the passage of the upper blank and a lower conveying sensor configured to detect the passage of the lower blank;

[0013] The registration control device also includes a control unit and a memory. The control unit is configured to receive detection signals from the upper transfer sensor and the lower transfer sensor, and calculate the total relative displacement between the upper blank and the lower blank. The control unit is also configured to activate the position correction device to provide a correction displacement in the transport direction to the upper blank so that the upper blank moves to be aligned with the lower blank.

[0014] The present invention is based on such a recognition that by correcting only the position of the upper blank, the production speed defined by the lower blank can be maintained. In a preferred embodiment, only the position of the upper blank is corrected. Therefore, the position of the lower blank is not corrected.

[0015] The total relative displacement is the displacement of the upper blank relative to the actual position of the lower blank in the transport direction and relative to the predefined assembly position of the upper and lower blanks. The total relative displacement is determined by the detection time of the leading edge of the upper and lower blanks passing each corresponding conveying sensor.

[0016] Thus, the actual position of the lower blank may be considered as a reference position for the upper blank, and the position correction means is configured to provide a correction displacement such that the upper blank is aligned with the lower blank at the joining point.

[0017] The transport direction can be defined as a horizontal direction extending from the upper and lower feeder devices to the junction point. The transport direction preferably coincides with the longitudinal direction of the converter. The transport direction extends between the inlet and outlet of the converter. Thus, the transport direction can extend from the upper and lower feeder devices to the folding and gluing module of the converter and further downstream to the conveying module of the converter.

[0018] Upstream of the junction, the transport path of the upper blank is inclined downwards. For the lower blank, the transport path upstream of the junction can be horizontal or have an inclination angle of about 15 °.

[0019] The term "upstream in the transport direction" refers to the direction from the junction point J to the upper feeder device. The term "downstream in the transport direction" refers to the direction from the upper feeder device to the junction point J.

[0020] The correction displacement corresponds to the relative total displacement. The displacement is provided by the acceleration or deceleration of the upper blank.

[0021] The memory preferably contains instructions for performing the calculations and temporary storage for storing the total relative displacement of each blank present between the feeder unit and the engagement point.

[0022] The upper conveyor system may include an alignment conveyor and a registration conveyor.

[0023] Preferably, the upper blanks are conveyed at a selected displacement distance such that each upper blank is moved relative to a predetermined register position of the upper blanks.

[0024] In a preferred embodiment, the selected displacement distance is chosen so that each upper blank always reaches the position of the upper transfer sensor with a total relative displacement relative to the lower blank, and wherein the position of each upper blank is corrected using a position correction device.

[0025] In one embodiment, the selected displacement distance is selected so that each upper blank needs to be corrected in the same direction in the upper transport path. The same direction means that each upper blank is corrected so that it is displaced in the upstream or downstream direction of the upper transport path and relative to the transport direction.

[0026] In one embodiment, the lower transfer sensor is configured to detect the actual position of the lower blank before the upper transfer sensor detects the actual position of the upper blank.

[0027] This allows the control unit to first determine a reference position based on the position of the lower blank.

[0028] Preferably, only the position of the upper blank is corrected.

[0029] In one embodiment, the lower transfer sensor is configured to detect the actual position of the lower blank before the upper transfer sensor detects the actual position of the upper blank.

[0030] In one embodiment, the position correction device comprises a housing shroud provided with an extension, which extends further upstream than the gripper belt in the transport direction, and wherein the upper transport sensor is located on said protruding extension.

[0031] In one embodiment, the actual speed of the upper blank is different from the actual speed of the lower blank.

[0032] In another embodiment, the release time of the upper blank or the actual transport speed of the upper blank is selected so that the upper blank has a selected displacement relative to the register position of the upper blank.

[0033] In one embodiment, the position correction device comprises a clamping belt provided with at least one abutment, and wherein the control unit is configured to position the abutment against the leading or trailing edge of the upper blank to modify the position of the upper blank in the transport direction.

[0034] The memory preferably includes a first set of operating instructions for a first operating mode in which the position correction device is configured to abut against the trailing edge of the upper blank so that each upper blank is accelerated by the position correction device, and a second set of instructions for a second operating mode in which the position correction device is configured to abut against the leading edge of the upper blank so that each blank is decelerated by the position correction device to reach a desired position. Acceleration or deceleration causes the upper blank to reach its desired position.

[0035] In one embodiment, the position correction device is connected to a shifting mechanism that is attached to the structural frame of the blank joining module, and wherein the position correction device can be shifted in the transport direction so that the position correction device can be moved to a first operating position in a first operating mode and to a second operating position in a second operating mode.

[0036] The shift mechanism includes a motor and a sliding mechanism, and the control unit is configured to actuate the motor to move the position correction device according to the longitudinal length of the upper blank and the type of correction mode selected. The sliding mechanism may include a slide rail and a slider.

[0037] In one embodiment, the registration control device further comprises an upper feed sensor and a lower feed sensor configured to detect the respective passages of the upper blank and the lower blank, and wherein the control unit is configured to determine an initial relative feeder displacement based on a difference in detection time, and wherein the control unit is configured to issue a warning signal if the initial relative feeder displacement is above a correction threshold.

[0038] In one embodiment, the upper conveyor system includes an alignment conveyor and a registration conveyor, and wherein the upper alignment conveyor is connected to the registration conveyor and an upper feeder, wherein the upper feeder is movable in a longitudinal direction, and wherein the upper alignment conveyor has a variable length.

[0039] In one embodiment, the control unit is configured to modify the release time and / or the transport speed of the upper blank based on the length of the upper alignment conveyor. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The present invention will now be described with reference to the accompanying drawings, in which like features are indicated by like reference numerals, and in which:

[0041] - Figure 1 is a schematic diagram of a converting machine configured as a folder-gluer;

[0042] - Figure 2a is a schematic perspective view of a folding box in a shelf-easy box configuration;

[0043] - Figure 2b Is used for production Figure 2a A plan view of a blank composed of a folding box;

[0044] - Figure 3 is a schematic perspective view of a blank joining module according to an embodiment of the present invention;

[0045] - Figure 4 yes Figure 3 A cross-sectional view of a blank joining module;

[0046] - Figure 5 is a schematic cross-sectional view of a feeder unit according to an embodiment of the present invention;

[0047] - Figure 6a is a schematic cross-sectional view of a position correction device according to an embodiment of the present invention;

[0048] - Figure 6b is a detailed view of the position correction device;

[0049] - Figure 7 is a schematic cross-sectional view of a lower alignment device according to an embodiment of the present invention;

[0050] - Figure 8a and Figure 8b is a schematic cross-sectional side view of an upper alignment device according to an embodiment of the present invention;

[0051] - Figure 8c yes Figure 8a and Figure 8b a schematic perspective view of an upper alignment device; and

[0052] - Figure 8d yes Figures 8a-8c A top view of the upper alignment device. DETAILED DESCRIPTION

[0053] With reference to the accompanying drawings, in particular with reference to Figure 1, which shows a converting machine 1 in the form of a folder-gluer 1. The folder-gluer 1 is configured to receive a first stack S1 and a second stack S2 of blanks 2, join them, and then fold and glue them together to form a folding box 2' or other composed packaging container.

[0054] The folder-gluer 1 can produce several types of boxes 2″, packaging containers as well as boxes. Figure 2a and Figure 2b One type of such a box 2″ is shown in FIG, which is commonly referred to as a “shelf-friendly” box 2″. This type of box 2″ consists of two blanks 2b, 2a joined together. One blank 2a can form an inner container and the other blank 2b can form an outer container. In use, the outer container can be manually removed while the inner container still holds the items to be stored.

[0055] The production of this type of composed box 2 ″ begins with forming a composed blank 2 ′ from a first blank 2 a and a second blank 2 b in a folder-gluer 1 . Subsequently, the composed blank 2 undergoes a folding and gluing operation.

[0056] like Figure 1 As shown, the folder-gluer 1 comprises a series of workstations in the form of different modules. From the inlet A to the outlet B, these modules may include: a blank joining module 10, a folding pre-breaking module 12, a gluing module 14 and a folding module 16. The folder-gluer 1 may also include a main user interface 11 and a quality control system 18. After the gluing and folding modules, a conveying module and a regulating section 20 may be provided to count the shingled flow of folded boxes 2" and divide them into separate batches. The conversion machine 1 also includes a conveying system 19, which includes a conveying device such as an endless belt and rollers, which is configured to transport the first blank 2a and the second blank 2b along the transport direction T. The conversion machine 1 also includes a control circuit 80 configured to control the operation of the blank joining module 10.

[0057] The blank joining module 10 enables the folder-gluer 1 to produce composed blanks 2'. Figure 3 and Figure 4 As shown, the blank joining module 10 includes a feeder unit 32 , an alignment unit 34 , a bonding device 100 , a registration control device 36 , and a joining conveyor device 38 .

[0058] like Figure 3 and Figure 4 As best shown, the feeder unit 32 comprises a lower feeder device 32a and an upper feeder device 32b. The upper feeder device 32b and the lower feeder device 32a are configured to feed the blanks 2a, 2b, respectively, one by one along the transport direction T.

[0059] The upper feeder device 32b is configured to feed a first blank 2b (also referred to as "upper blank" 2b) from a stack located on an upper loading surface 33b. The lower feeder device 32a is configured to feed a second blank 2a (also referred to as "lower blank" 2a) from a stack located on a lower loading surface 33a in the lower feeder device 32a.

[0060] The upper loading surface 33b is located directly above the lower loading surface 33a. To facilitate access to the upper loading surface 33b, the upper feeder device 32b can be displaced in the longitudinal direction L and the transport direction T1. This allows the upper loading surface 33b to be displaced to a horizontally offset position relative to the lower loading surface 33a. This allows the upper loading surface 33b to be moved closer to the machine operator.

[0061] like Figure 3-Figure 5 As best shown, the upper feeder device 32b is slidably mounted on the structural frame 40 of the blank engaging module 10. The connection between the upper feeder device 32b and the structural frame 40 can be achieved by a sliding connection. The sliding connection can include a slide rail 42 and a slider 41. The upper feeder device 32b can be moved along the slide rail 42 by a motor 44. The motor 44 can perform an automatic displacement of the upper loading surface 33b. The control circuit 80 of the blank engaging module 10 can automatically operate the motor 44 to move the upper feeder device 32b to a predetermined operating position calculated based on the longitudinal length La of the lower blank 2a in the lower feeder device 32a. The longitudinal length La is the length of the lower blank 2a along the transport direction T.

[0062] To further facilitate access to the upper feeder device 32b, the blank engaging module 10 may also include a modular podium 50. Figure 3 As best shown, the base 50 includes at least one stepping surface 52a. Preferably, the base 50 includes a second stepping surface 52b movably disposed on top of the first stepping surface 52a.

[0063] like Figure 4 As shown, the alignment unit 34 is arranged downstream (in the transport direction T) of the feeder unit 32 and is configured to align the upper blank 2b and the lower blank 2a laterally to their respective predetermined lateral positions. In this way, when the blanks 2a, 2b contact each other at the junction J, the upper blank 2b and the lower blank 2a are in the correct lateral position.

[0064] The alignment unit 34 comprises an upper alignment device 34b configured to align the upper blank 2b and a lower alignment device 34a configured to align the lower blank 2a. The upper alignment device 34b and the lower alignment device 34a are provided with respective distal upstream connection ends 35b, 35a, which are preferably fixedly connected to the upper feeder device 32b and the lower feeder device 32a.

[0065] The lower alignment device 34a is configured to transport the lower blank 2a along a substantially horizontal transport path Pa. Figure 7 As best shown, the lower alignment device 34a includes an upper pressing member 60a, a lower conveyor 61a, and a guide (not shown). The lower conveyor 61a includes an endless conveyor belt 62a having a contact length Lca, which is configured to contact the lower blank 2a and drive the lower blank 2a forward along the transport direction T.

[0066] like Figures 8a-8d As best shown, the upper alignment device 34b includes an upper pressing member 60b and an upper conveyor 61b. The guide 63 is arranged so that it is straight in the transport direction T. The upper pressing member 60b and the upper conveyor 61b are arranged at a certain angle in the transport direction T so that the lateral edge of the lower blank 2a abuts the guide 63. The upper conveyor 61b includes an endless conveyor belt 62b having a contact length Lcb, which is configured to contact the upper blank 2b and drive the upper blank 2b forward in the transport direction T.

[0067] Thus, the upper alignment device 34b is configured similarly to the lower alignment device 34a. However, the upper alignment device 34b has a variable contact length Lcb in the transport direction T. The upper alignment device 34b also includes a movable distal end 35a connected to the upper feeder device 32b and a fixed distal end 37b connected to the structural frame 40 of the blank joining module 10. This allows the upper feeder device 32b to be displaced in the longitudinal direction L while maintaining a fixed connection to the upper alignment device 34b.

[0068] like Figure 8b and Figure 8c As best shown, the upper conveyor 61b of the upper alignment device 34b further includes a support structure 69 configured to support the conveyor belt 62b. The support structure 69 includes a plurality of rollers 67 (see FIG. Figure 8a ), the conveyor belt 62b is mounted on rollers 67. The rollers 67 are attached to the frame members 70, and the connecting mechanism 68 connects adjacent frame members 70 to each other. The connecting mechanism 68 is expandable so that the distance between the frame members 70 can be modified. The frame members 70 are displaceable in the transport direction T. Each roller 67 is attached to the frame member 70 and arranged in a straight line.

[0069] Preferably, the connecting mechanism 68 includes a plurality of pivotable links 74a, 74b that allow for equidistant displacement of the frame members 70. The pivotable connecting links 74a, 74b can be provided by two linear elements. The pivotable connecting links 74a, 74b are connected to each frame member 70 in a central pivot 75. The pivotable connecting links 74a, 74b are also connected to each other in an upper pivot 76 and a lower pivot 77. The upper pivot 76 and the lower pivot 77 are movable in the longitudinal direction L.

[0070] The horizontal position of the central pivot 75 is maintained constant by connecting the frame member 70 to the central pivot 66. The support structure has a first distal end 35b connected to the upper feeder device 32b and a second distal end 37b connected to the frame 40 of the blank engagement module 10.

[0071] The frame member 70 is connected to the central pivot 75 of the connection mechanism 68. The frame member 70 includes a first cantilever extension 70a and a second cantilever extension 70b that are connected to a frame member bracket 70c.

[0072] The guide roller 67 of the conveyor belt 62b is attached to the first cantilever extension 70a, and the pressure roller 66 is attached to the second cantilever extension 70b. The first cantilever extension 70a and the second cantilever extension 70b extend horizontally and parallel to each other. The second cantilever extension 70b is arranged directly above the first cantilever extension 70a.

[0073] The second cantilever extension 70b may be supported by an upper rail 71b, and the second cantilever extension 70b may be supported by a lower rail 71a. The rails 71a, 71b may be in the form of longitudinal bars disposed below the first and second cantilever extensions 70a, 70b, respectively.

[0074] The distal inlet end 35b of the upper alignment assembly 34b may include an attachment bracket 79 configured to attach to the upper feeder assembly 32b. The attachment bracket 79 also provides a fixed structure to form an inlet portion I for the upper press roller 66 and the support roller 67 of the conveyor belt 62b. The attachment bracket 79 provides a fixed connection to the cantilever extensions 70b, 70c, ensuring that the inlet portion I has a constant length regardless of whether the connection mechanism 68 is extended or retracted. A distal center pivot 79a is attached to the attachment bracket 79. A second distal center pivot 79b is attached to the frame member 77 of the upper alignment module 34b.

[0075] The guide 63 is not present in the inlet portion I defined by the length of the attachment bracket 79. Thus, the upper blank 2b is not guided in the inlet portion I. This allows the upper blank 2b to be carried out of the upper feeder device 32b before being pushed sideways.

[0076] The register control device 36 is configured to compensate for longitudinal register offsets in the transport direction T and align the upper and lower blanks 2b, 2a with each other in the transport direction T. Longitudinal register offsets are undesired displacements of the blanks 2a, 2b relative to their predefined longitudinal register positions Pa_reg, Pb_reg at a specific moment.

[0077] Both the upper blank 2b and the lower blank 2a will experience a registration displacement offset due to changes in blank transportation. Such changes may include changes in the feeder discharge time, which results in the feeder displacement Δdb_feeder (Δdb_feeder) and Δda_feeder (Δda_feeder) at the corresponding upper feeder device 32b and the lower feeder device 32a. The discharge time of the upper feeder device 32b and the lower feeder device 32a can be advanced or delayed relative to their predetermined discharge time. Another change is the transport displacement Δdb_transport (Δdb_transport) and Δda_transport (Δda_transport) of the upper blank 2b and the lower blank 2a, which is caused by local wear of the conveyor belt and related support components.

[0078] like Figure 4 6 , the register control device 36 includes a sensing system 83 , a position correction device 86 , and a control circuit 84 . The control circuit includes a control unit 91 and a memory 93 .

[0079] like Figure 6a and Figure 6b As best shown, the position correction device 86 includes a cleat belt 88 mounted on a belt drive mechanism 104. The belt drive mechanism 104 is attached to a frame member 105. The cleat belt 88 is configured to be driven at variable acceleration and speed. The cleat belt 88 is provided with one or more supports 90. Preferably, two supports 90 are provided. The position correction device 86 also includes a motor 92 configured to drive the cleat belt 88.

[0080] The position correction device 86 may include an inductive sensor 89 configured to detect the position of the cleat strip 88, thereby determining the position of the support 90. The inductive sensor 89 may be configured to sense the support 90. The support 90 may include a metal material that can be sensed by the inductive sensor 89.

[0081] By making the support 90 abut against the leading edge E1b or trailing edge E2b of the upper blank 2b and accelerating or decelerating the upper blank 2b in the transport direction T, the position of the upper blank 2b can be corrected. Therefore, two different operating modes O1 and O2 can be provided. In the first operating mode O1, the support 90 of the position correction device 86 contacts the trailing edge E2b of each upper blank 2b and provides acceleration. In the second operating mode O2, the support 90 of the position correction device contacts the leading edge E1b of each upper blank 2b and provides deceleration. For the two operating modes O1 and O2, the position of the position correction device 86 can be different. In the second correction mode O2, the position correction device 86 is preferably closer to the junction point J than in the first correction mode O1.

[0082] The position correction device 86 can be mounted to the slide rail 95. This allows the position correction device 86 to be positioned according to the type of operating mode O1, O2 and the longitudinal length Lb of the upper blank 2b in the transport direction T. This allows the support 90 to be positioned against either the trailing edge E2b or the leading edge E1b of the upper blank 2b.

[0083] like Figure 4 As shown, the sensing system 83 includes an upper transfer sensor 81b configured to detect the passage of the leading edge E1b of the upper blank 2b and a lower transfer sensor 81a configured to detect the passage of the leading edge E1a of the lower blank 2a. The upper transfer sensor 81b and the lower transfer sensor 81a are located a certain distance upstream of the junction J.

[0084] 6, the upper transfer sensor 81b is preferably mounted on a protruding extension 87 of the position correction device 86. The protruding extension 87 may be connected to the frame member 105 of the position correction device 86. The protruding extension 87 positions the upper transfer sensor 81b upstream of the cleat belt 88.

[0085] The control unit 91 is configured to receive detection signals from the upper transfer sensor 81b and the lower transfer sensor 81a and determine the actual position Pb_act2, Pa_act2 of the upper blank 2b and the lower blank 2a at each corresponding transfer sensor 81a, 81b. The actual position Pa_act2, Pb_act2 of the upper blank 2a and the lower blank 2b is the position along the transport direction T at a predetermined time. The predetermined time can be defined based on the duration of time that has passed since the discharge signal from the lower feeder was issued.

[0086] The register control device 36 further includes an upper register conveyor 78 configured to transport the upper blank 2b and a lower transport conveyor 79 configured to transport the lower blank 2a. The upper register conveyor 78 and the lower transport conveyor 79 transport the upper blank 2b and the lower blank 2a toward the junction J, respectively.

[0087] The upper blank 2b has a transport path Pb extending from the upper feeder device 32b to the junction J. The lower blank 2a has a transport path Pa extending from the lower feeder device 32a to the junction J.

[0088] The upper transport path Pb has an upper conveyor system 31b including an upper alignment device 34b and an upper registration conveyor 78. The lower transport path Pa has a lower conveyor system 31a including a lower alignment device 34a and a lower transport conveyor 79.

[0089] The register control device 36 is preferably configured to correct only the position of the upper blank 2b. Because the lower blank 2a also experiences register displacement, the actual position Pa_act2 of each lower blank 2a at the lower transport sensor 81a is selected as the reference position for each associated upper blank 2b. Before the upper blank 2b reaches the junction point J, the position of each upper blank 2b is modified using the position correction device 86.

[0090] The detection times from the respective transfer sensors 81a, 81b define the actual positions Pb_act2 and Pa_act2 of the upper and lower blanks 2b, 2a. The lower transfer sensor 81a is located a distance upstream of the junction J. Since the upper transfer sensor 81b is preferably mounted on a protruding extension 87 connected to the position correction device 86, the passage of the upper blank 2b can be detected before the upper blank 2b comes into contact with the clamping belt 88.

[0091] The control circuit 84 is configured to calculate a corresponding desired position Pb_des of the upper blank 2b at the conveying sensor 81b based on the actual position Pa_act2 of the lower blank 2a. The desired position Pb_des of the upper blank 2b is the position where the upper blank 2b is aligned with the lower blank 2a in the transport direction T. Aligning the upper blank 2b with the lower blank 2a means that the upper blank 2b is conveyed so as to be superimposed on the lower blank 2a at a position corresponding to a designated assembly position in the transport direction T.

[0092] The control unit 91 is configured to calculate the desired position Pb_des of each upper blank 2 b by determining the actual position Pa_act2 of each associated lower blank 2 a and executing an algorithm stored in the memory 93 .

[0093] Since the inclined upper transport path Pb is longer than the lower transport path Pa, the actual transport speed Vb_act of the upper blank 2b upstream of the junction J may be higher than the actual transport speed Va_act of the lower blank 2a.

[0094] Because the length of the upper transport path Pb can vary depending on the contact length Lcb of the extendable upper alignment device 34b, the control unit 91 can calculate the theoretical transport speed Vb_t of the upper blank 2b based on the position of the upper feeder device 32b. The position of the upper feeder device 32b can be determined based on the longitudinal length La of the lower blank 2a. Therefore, the position of the upper feeder device 32b can determine the length of the upper transport path Pb and the theoretical transport speed Vb_t. The theoretical transport speed Vb_t can then be calibrated using the sensing system 83 so that the upper blank 2b reaches a suitable position relative to the lower blank 2a. This suitable position allows for position correction using the position correction device 86.

[0095] The position correction device 86 is configured to correct the position of the upper blank 2 b by accelerating or decelerating each upper blank 2 b in the transport direction T.

[0096] Preferably, the upper blank 2b is conveyed with a selected displacement Δd_selected in the transport direction T. The selected displacement Δd_selected is a deliberately selected displacement distance relative to the predefined register position Pb_reg of the upper blank 2b at the upper transport sensor 81b. This selected displacement Δd_selected ensures that each upper blank 2b always arrives at the upper transport sensor 81b with a register displacement distance Δdb.

[0097] The selected displacement distance Δd_select is selected as an amount that can be corrected by the position correction device 86. The displacement distance Δd_select is preferably 10-15 mm.

[0098] This deliberately selected displacement distance Δd_selects either delay or advance. Delay means that each upper blank 2b always arrives at the transfer sensor 81b too late relative to the registration position Pb_reg. Advance means that each upper blank 2b always arrives at the transfer sensor 81b too early relative to the registration position Pb_reg.

[0099] The selected displacement distance Δd_selected can be provided by selecting the actual transport speed Vb_act of the upper blank 2b such that the predefined selected displacement Δd_selected always occurs at the position of the upper transport sensor 81b.

[0100] In another advantageous embodiment, the release time of the upper feeder device 32b can be selected so that the upper blank 2b is conveyed with a selected displacement Δd_selected. Thus, when the upper blank leaves the upper feeder device 32b, this displacement has already occurred. This time offset represents a time delay or a time advance of the upper blank 2b relative to the register position Pb_reg of the upper blank 2b.

[0101] The upper feeder device 32b has a theoretical release time t_b_register so that the upper blank 2b is in register position and aligned with the lower blank 2a. Similarly, the lower feeder device has a theoretical release time t_b_register so that the lower blank 2a is discharged at a timed and registered position.

[0102] The time deviation Δt_b is therefore added to the theoretical release time t_b_register of the upper blank 2 b .

[0103] The actual release time tb_actual of the upper blank 2b is selected as:

[0104] tb_actual = t_b_register + Δt_b

[0105] In this embodiment, the actual transport speed Vb_act of the upper blank 2b is selected so that the upper blank 2b is theoretically located at the registration position and thus reaches the upper transfer sensor 81b at the registration position. The actual transport speed Vb_act of the upper blank 2b can be higher than the actual transport speed Va_actual of the lower blank 2a, but only to accommodate the length difference between the upper transport path Pb and the lower transport path Pa.

[0106] At the upper transfer sensor 81b, the displacement Δdb of the upper blank 2b relative to the upper blank registration position Pb_reg can be calculated based on the arrival time of the upper blank 2b at the upper transfer sensor 81b. This is valid regardless of whether the upper blank 2b has a time deviation Δt_b or has a transport speed generated at the selected displacement of the upper transfer sensor 81b.

[0107] The displacement Δdb includes a selected displacement Δd_selected, a feeder displacement error Δdb_feeder (Δdb_feeder), and a transport displacement Δdb_transportation (Δdb_transportation).

[0108] Figure 9 The first operating mode O1 is shown, in which the upper blanks 2b are conveyed with a delayed time offset Δt_b, which is added to the release time tb_actual. Alternatively, the actual transport speed Vb_act is lower than the theoretically required speed Vb_t. This results in a predefined and selected negative displacement Δd_selected being added to each upper blank 2b. Consequently, all upper blanks 2b arrive at the upper transport sensor 81b with a time delay.

[0109] Figure 10A second operating mode O2 is shown, in which the blanks are conveyed with an advance time offset Δt_b, which is added to the release time tb_actual. Alternatively, the actual transport speed Vb_act is higher than the theoretically required speed Vb_t. This results in a predefined and selected positive displacement Δd_selected being added to each blank. As a result, all upper blanks 2b arrive at the upper transport sensor 81b earlier than expected.

[0110] exist Figure 9 and Figure 10 In the illustrated modes O1 and O2, the upper blank 2b has received the time deviation Δt_b and the selected displacement Δd_selected has been effective at the upper feeder device 32b. If the actual transport speed Vb_act is selected to produce the displacement Δd_selected, the displacement Δd_selected is preferably gradual and effective in its entirety at the upper conveyor sensor 81b.

[0111] The sensing system 83 may also include an upper feed sensor 85b located a distance downstream of the upper feeder device 32b and a lower feed sensor 85a located a distance downstream of the lower feeder device 32a.

[0112] The upper feed sensor 85b and the lower feed sensor 85a detect the passage of the leading edges E1b and E1a of the upper and lower blanks 2b and 2a, respectively. The passage of the leading edges E1b and E1a of the upper and lower blanks 2b and 2a can be used to determine the actual positions Pb_act1 and Pb_act2 of the blanks 2b and 2a at the respective feed sensors 85b and 85a and when they are discharged from the upper and lower feeder devices 32b and 32a. In an embodiment in which a time offset is provided for the upper blank 2b, the feeder displacement Δdb_feeder and the actual position Pb_act1 of the upper blank 2b at the feed sensor 85b can be determined by the following relationship:

[0113] Pb_act1=P_reg1-Δdb_feeder-Δd_selected

[0114] Δdb_feeder = Pb_act1 - Pb_reg1

[0115] The actual position Pa_act1 of the lower blank 2a at the lower feed sensor 85a and the feeder displacement Δda_feeder can be determined by the following relationship:

[0116] Pa_act1=P_reg1-Δda_feeder

[0117] Δda_feeder = Pa_act1 = P_reg1

[0118] Based on the actual positions Pb_act1, Pb_act2 provided by the upper feed sensor 85b and the lower feed sensor 85a, the initial relative displacement Δdb_initial of the upper blank 2b relative to the lower blank 2a can be calculated. Based on the initial relative displacement, the preliminary required correction of the support 90 on the clamping belt 88 can be determined.

[0119] Δdb_initial = Δdb_feeder - Δda_feeder

[0120] This initial preliminary required correction Δdb_initial is advantageous for calculation because the feeder displacements Δda_feeder, Δdb_feeder are typically higher than the transport displacements Δda_transport, Δdb_transport. Based on the initial preliminary required correction Δdb_initial, control unit 91 can determine whether position correction device 86 is capable of correcting the initial preliminary required correction Δdb_initial. If the required correction Δdb_initial is greater than the correction threshold T_corr of position correction device 86, control unit 91 can generate a control signal to issue a warning or shut down conversion machine 1.

[0121] The register displacement Δda of the lower blank 2a at the lower transfer sensor 81a is calculated based on the difference between the detected actual position Pa_act2 of the lower blank 2a and the corresponding register position Pa_reg2. Therefore, the following relationship applies:

[0122] Δda=Pa_act2–Pa_reg2

[0123] Δda=Δda_feeder+Δda_transport

[0124] For the upper blank 2b, the registration displacement Δdb at the upper transport sensor 81b and relative to the predefined registration position of the upper blank Pb_reg2 is:

[0125] Δdb=Pb_act2–Pb_reg2

[0126] Δdb=Δd_selected + Δdb_feeder + Δdb_transport

[0127] The displacement Δdb is therefore the sum of the feeder register displacement Δd_feeder, the transport displacement and the selected predefined displacement Δd_selected of the upper blank 2b.

[0128] The total relative displacement Δdb_total of the upper blank 2b with respect to the lower blank 2a at the transfer sensors 81a, 81b is the register displacement Δdb of the upper blank 2b minus the register displacement Δda of the lower blank 2a.

[0129] Therefore, the total relative displacement Δdb_total between the upper blank 2b and the lower blank 2a at the positions of the upper transfer sensor 81b and the lower transfer sensor 81a can be calculated as follows:

[0130] Δdb_total=Δdb-Δda

[0131] The position correction device 86 is configured to provide a displacement correction Δc to each blank 2b along the transport direction T. The correction Δc is equal to the total relative displacement Δdb_total. In this way, the upper blank 2b is shifted to the desired position P_des_b determined by the control unit 91. Thus,

[0132] Δc = Δdb_total

[0133] In the first operating mode O1 , the position correction device 86 is configured to accelerate the upper blank 2b so as to provide a position correction Δc to each blank 2b. In the first operating mode O1 , the position correction device 86 is positioned so that the support 90 contacts the trailing edge E2b of the upper blank 2b.

[0134] In the second operating mode O2 , the position correction device 86 is configured to decelerate the upper blank 2 b in order to provide a position correction Δc for each blank 2 b .

[0135] In the first operating mode O1 , for an upper blank 2 b having a smaller longitudinal length Lb, the position correction device 86 is preferably positioned closer to the joining point J than in the case of a longer blank 2 b.

[0136] Providing two operating modes O1, O2 may also allow the position correction device 86 to be set against the optimum edges of the leading edge E1b and the trailing edge E2b. Ideally, the optimum edges are straight or uniform edges.

[0137] The position correction device 86 may further include a shifting motor 97 configured to automatically shift the position correction device 86 along the slide rail 95. The longitudinal position of the position correction device 86 is selected based on the type of correction mode O1, O2 and the longitudinal length of the upper blank Lb.

[0138] The blank joining module 10 further includes a gluing device 100 arranged upstream of the joining point J. The gluing device may include a glue reservoir, a pump, and a dispensing nozzle. Preferably, the gluing device 100 is arranged to dispense glue onto the top side of the lower blank 2a so that the glue is located between the upper blank 2b and the lower blank 2a. Preferably, the gluing device 100 is activated based on the detection time of the lower transport sensor 81a.

Claims

1. A blank joining module, comprising an upper feeder device (32b) configured to feed an upper blank (2b), a lower feeder device (32a) configured to feed a lower blank (2a), and an upper conveying system (31b) configured to transport the upper blank from the upper feeder device, and a lower conveying system (31a) configured to transport the lower blank from the lower feeder device, wherein the upper conveying system and the lower conveying system are configured to transport the upper blank and the lower blank toward a joining point (J), and the upper blank is positioned on the lower blank at the joining point, The blank joining module comprises a register control device (36) including a sensing system (83) and a position correction device (86), and wherein the sensing system comprises an upper conveying sensor (81b) configured to detect the passage of the upper blank and a lower conveying sensor (81a) configured to detect the passage of the lower blank, And wherein the registration control device also includes a control unit (91) and a memory (93), the control unit is configured to receive detection signals from the upper transfer sensor and the lower transfer sensor and calculate the total relative displacement (Δdb_total) between the upper blank and the lower blank, and the control unit is also configured to activate the position correction device (86) to provide a correction displacement (Δc) to the upper blank so that the upper blank is shifted to be aligned with the lower blank.

2. The blank joining module according to claim 1, wherein the upper blank (2b) is conveyed at a selected displacement distance (Δd_selected) so that each upper blank is displaced relative to its predefined registration position (Pb_reg2) at the upper conveying sensor (81b).

3. A blank joining module according to claim 2, wherein the selected displacement distance (Δd_selected) is selected so that each upper blank (2b) always reaches the position of the upper conveying sensor (81b) with a total relative displacement (Δdb_total) relative to the lower blank (2a), and wherein the position of each upper blank (2b) is corrected using the position correction device (86).

4. The blank engagement module according to claim 2, wherein the selected displacement distance (Δd_selected) is selected such that each upper blank requires a correction in the same direction in the upper transport path (Pb).

5. A blank joining module according to any one of the preceding claims, wherein only the position of the upper blank is corrected.

6. The blank joining module according to any one of the preceding claims, wherein the lower transfer sensor is configured to detect the actual position (Pa_act2) of the lower blank before the upper transfer sensor detects the actual position (Pb_act2) of the upper blank.

7. The billet joining module according to any of the preceding claims, wherein the actual speed (Vb_act) of the upper billet is different from the actual speed (Va_act) of the lower billet.

8. A blank joining module according to any one of claims 1-8, wherein the actual release time (tb_actual) of the upper blank (2b) or the actual transport speed (Vb_act) of the upper blank (2b) is selected so that the upper blank has a selected displacement (Δd_selected) relative to the registration position (Pb_reg) of the upper blank.

9. A blank joining module according to any one of the preceding claims, wherein the position correction device comprises a clamping belt provided with at least one support (90), and wherein the control unit is configured to position the support to abut against the leading edge (E1b) or the trailing edge (E2b) of the upper blank (2b) to modify the position of the upper blank (2b) in the transport direction.

10. A blank joining module according to any one of the preceding claims, wherein the position correction device comprises a shell shield provided with an extension portion, which extends further upstream than the clamping belt in the transport direction (T), and wherein the upper transfer sensor is located on the protruding extension portion (87).

11. A billet joining module according to claim 9 or 10, wherein the memory includes a first set of operating instructions for a first operating mode (O1) and a second set of instructions for a second operating mode (O2), wherein in the first operating mode, the position correction device is configured to abut against the trailing edge of the upper billet so that each upper billet is accelerated by the position correction device, and in the second operating mode, the position correction device is configured to abut against the leading edge of the upper billet so that each billet is decelerated by the position correction device.

12. A blank joining module according to the preceding claim, wherein the position correction device is connected to a shifting mechanism, the shifting mechanism is attached to the structural frame (40) of the blank joining module, and wherein the position correction device can be shifted in the transport direction so that the position correction device can be moved to a first operating position in the first operating mode and to a second operating position in the second operating mode.

13. A blank joining module according to the preceding claim, wherein the shifting mechanism comprises a motor and a sliding mechanism, and wherein the control unit is configured to actuate the motor to move the position correction device according to the longitudinal length (La) of the upper blank and the type of correction mode (O1, O2) selected.

14. A blank joining module according to any one of the preceding claims, wherein the registration control device further comprises an upper feed sensor and a lower feed sensor, configured to detect the respective passage of the upper blank and the lower blank, and wherein the control unit is configured to determine an initial relative feeder displacement (Δdb_initial) based on a detection time difference, and wherein the control unit is configured to issue a warning signal if the initial relative feeder displacement (Δdb_initial) is higher than a correction threshold (T_corr).

15. A blank joining module according to any one of the preceding claims, wherein the upper conveying system includes an alignment conveying device and a registration conveying device, and wherein the upper alignment conveying device is connected to the registration conveying device and an upper feeder, wherein the upper feeder is movable in a longitudinal direction (L), and wherein the upper alignment conveying device has a variable length.

16. The blank engagement module according to the preceding claim, wherein the control unit is configured to modify the release time and / or the transport speed of the upper blank based on the length of the upper alignment conveyor.

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