Patent Application
20190047805
The present invention relates to a handling system for handling stackable flat elements, in particular carton elements, in particular during transporting a stack of flat elements to a processing device.
In the processing industry, raw material, such as flat carton elements, is delivered in large units. The large units of the carton elements have to be assembled into stacks comprising a predefined number of carton elements before the carton elements can be further processed in a processing unit, such as a printing machine for printing desired designs onto the carton elements.
The stacks comprise a desired quantity of cartons and are handled e.g. by complex robot arms or by manually controlled cranes, for example. During the manufacturing and finishing steps of the carton elements, stacks of carton elements have to be moved several times between the processing devices. The stack have to be treated very carefully in order to prevent damage to the sensitive carton elements. Hence, complex handling mechanisms have to be used to transport the stacks of cartoon elements between the processing devices.
There may be a need to provide a handling system for handling carton elements with a reduced risk of damaging the carton elements.
According to a first aspect of the present invention, a handling system for handling stackable flat elements, in particular carton elements, is presented. The handling system comprises a supporting table having a supporting surface onto which at least an edge portion of a stack of flat elements is supportable. The handling system further comprises a clamping device configured for clamping a first part of the stack to the supporting table and a lifting device configured for lifting a second part of the stack from the supporting table. The lifting device and the clamping device are arranged to the supporting table such that the stack is bendable by clamping the first part of the stack onto the supporting table by the clamping device and at the same time lifting the second part of the stack from the supporting table by the lifting device at the same time, such that the stack is bent around a bending axis, wherein the bending axis extends within a plane parallel to a supporting plane of the supporting surface.
According to a second aspect of the invention, a method for handling stackable flat elements, in particular carton elements, is presented. According to the method, at least an edge portion of a stack of flat elements is arranged onto a supporting surface of a supporting table. The stack is bendable by clamping a first part of the stack onto the supporting table by a clamping device and at the same time by lifting a second part of the stack from the supporting table by the lifting device, such that the stack is bent around a bending axis, wherein the bending axis extends within a plane parallel to a supporting plane of the supporting surface.
The flat elements as described above describe in general elements which are stackable and which comprise a larger width and length than the thickness. The stackable flat elements may include elements which can be stacked onto each other without any fixing means. The flat elements as described above denote elements which are stacked onto each other, wherein the resulting stack can be statically robust such that the stack does not need any holding systems for preventing tilting of the stack. More specifically, the flat elements may comprise a thickness which is less than 10 cm and a length and width of more than 10 cm. Specifically, in a preferred embodiment, the flat elements are non-folded cartons. However, other flat elements, such as sheet elements or other plate like elements can be handled by the handling system.
The stackable flat elements may be carton elements, such as of corrugated card board. The carton elements may be made of paper, cardboard, flexible materials such as sheets made of metal or plastic. The carton elements may be used for forming wrappers and packages.
In the present description, an edge portion of the stack denotes a portion of the stack between an edge and a center portion of the stack within a plane along which the length and the width of the stack are defined. The edge portion runs along an edge of the stack and may have an area within the plane of ⅓ to 1/10 times or less than the area of a center portion of the stack. The centre portion of a stack is surrounded by edge portions running along respective edges of the stack, wherein the edge portions define areas between the center portion and the respective edges of a stack. Specifically, the edge portion and the further edge portion which are described herein denote opposite edge portions of a stack.
The first part defines a section of the stack which contacts the clamping device when clamping the stack to the supporting table by the clamping device. Specifically, the first part is defined by a contact region of the clamping device with a first top sheet (flat element) of the stack. The second part defines a section of the stack which contacts the lifting device when it lifts the stack from the supporting table. Specifically, the second part is defined by a contact region of the lifting device with a second lower/bottom sheet (flat element) of the stack.
In a preferred embodiment, the first part and the second part are defined within the edge portion of the stack. The edge portion of the stack is initially bent by the clamping device and the lifting device, wherein by bending the edge portion, additionally, the center portion and the opposed further edge portion are bent around the bending axis as well, also if the clamping device and the lifting device acts onto the stack only at the edge portion.
The supporting table is configured for supporting at least an edge portion of the stack. The supporting table comprises in particular a supporting surface onto which the stack is partially arrangeable. If the clamping device does not clamp the stack to the supporting table, the stack may slide along the supporting surface until the stack is located at the defined position onto the supporting table. The supporting surface may form a flat and uncurved surface or a slightly curved surface. The supporting surface may be formed within a horizontal plane. Alternatively, the supporting surface may be inclined with respect to the horizontal plane. This means, that the normal of the supporting surface may have an angle to the normal of the horizontal plane of for example approximately 1° to approximately 45°.
The clamping device may comprise a clamping element, such as a clamping bar extending along the first part of the stack. Alternatively, the clamping element is a stamp which is formed to clamp the first part of the stack against the supporting table. The clamping device may be movable along a vertical direction and may move along the clamping direction from a position spaced apart from the supporting table to a position closer to the supporting table for thereby clamping the first part of the stack between the clamping device and the supporting table.
The lifting device may comprise a lifting element, such as a lifting platform, a lifting lever or a lifting stamp, extending along the second part of the stack. The lifting device may be mounted to the supporting table and may be integrated within the supporting table in such a way that the lifting lever forms a flat and homogeneous surface with the supporting surface, wherein the lifting element may come up from the supporting surface along the lifting direction for lifting the second part of the stack. The lifting direction defines a direction having a vertical component, wherein the lifting element extends along the lifting direction when coming up from the supporting surface.
Before bending the stack of flat elements, the stack rests on the supporting surface of the supporting table. The supporting surface defines for example the supporting plane. Hence, if the stack of flat elements is arranged onto the supporting surface, each of the flat elements is arranged within a respective plane which is spaced apart from and parallel to the supporting plane. Hence, if the stack is unbent and has only a general two dimensional extension within the respective plane, the stack and the flat elements, respectively, are easy to deform around a deforming axis which extends within the respective plane. This deforming around the deforming axis is not desired, because it causes unwanted deforming of the stack during handling of the stack.
In the present invention, the stack of the elements is bent such that the stack and each flat element, respectively, is bent by the lifting device and the clamping device around a bending axis. Metaphorically speaking, a cross-section of the stack has a U-shape. The bending by cooperation of the lifting device and the clamping device describes bending which causes an elastic and non-plastic deformation of the stack. Thus, the bending by the lifting device and the clamping device does not include folding or cracking of the stack and the flat elements, respectively. The bent cross-section may be described in an abstract manner by a bending line, wherein the bending axis runs through the centers of curvature of the bending lines of respective cross sections of the stack.
Unwanted deforming of the stack around a deforming axis (which extends within the plane and differs (e.g. being perpendicular) to the above described bending axis) is avoided because the stack is stiffer against deformation around the deformation axis due to having the U-shaped cross-section. Hence, handling the stack in a bent and stiffer state reduces the risk of damaging the flat elements because the risk of unintentional folding or cracking around a deformation axis is reduced.
In order to achieve the above effect, a slight bending of the stack around the bending axis may be sufficient. For example, while the first part of the stack is clamped to the supporting table by the clamping device, the second part of the stack is lifted by the lifting device with respect to the first part by a vertical distance between the first part and the second part of approximately 5 cm to approximately 40 cm, for example.
According to an exemplary embodiment of the present invention, the supporting table is movable along a moving direction having a horizontal component between a first position and a second position. The clamping device is configured for clamping the stack to the supporting table during movement of the supporting table between the first position and the second position. For example, the supporting table may comprise roller elements for moving along a moving direction. For example, the supporting table may be arranged onto a guiding rail, for example. In an exemplary embodiment, the clamping device and the lifting device are mounted to the supporting table such that the clamping device and the lifting device move together with the supporting table along the moving direction.
For example at the first position, the stack is arranged onto the supporting surface of the supporting table. Next, the clamping device and the lifting device fix the stack. In this fixed and bent state, the supporting table moves along the moving direction to a desired second position, where the clamping device and the lifting device release the stack such that the stack is available for further processing or transportation away from the supporting table. During the transportation between the first position and the second position, the stack is in a bent state and is more robust and stiffer against undesired deformation around the deformation axis.
According to a further exemplary embodiment, the lifting device comprises at least one lifting element (as described above) which is movable along a lifting direction having at least one vertical component. In a further exemplary embodiment, the lifting element is mounted to the supporting table such that the lifting element is extendible from the supporting surface of the supporting table, onto which supporting surface the stack is arrangeable. The lifting element may be driven hydraulically, pneumatically or by an electronic motor.
According to a further exemplary embodiment, the lifting element is configured to be extendible in a telescopic manner. Hence, the lifting element may be formed as a telescopic rod which is for example installed into the supporting table. Hence, in order to lift the second part of the stack, the telescopic rods may be extendable along the lifting direction.
According to a further exemplary embodiment, the lifting element is configured to be extendible by being pivoted around a pivoting axis. For example, the lifting element is formed as a lever which is mounted pivotable to the supporting table. Hence, in order to lift the second part of the stack, the pivotable lever may be pivoted around a pivot axis, such that a part of the lever spaced apart from the pivot axis lifts along the lifting direction.
A first end of the pivotable lever is fixed pivotably to the supporting table. An opposed second end of the pivotable lever defines a free end which lifts along the lifting direction and thereby contacts the second part of the stack. In a preferred embodiment, the first end is located at a center section of the supporting table and the opposed second end of the lever is located more to an edge section of the supporting table (which edge section surrounds the center section of the supporting table). Hence, when pivoting the lever around the pivot axis, the free second end of the lever lifts with a larger distance from the supporting table than would other sections of the lever such that an inclined lifting surface is formed. The inclined lifting surface passive smooth and gentle bending of the first part of the stack.
According to a further exemplary embodiment, the lifting device comprises at least one further lifting element which is movable along the lifting direction. It has at least one vertical component, wherein the further lifting element is spaced apart from the lifting element.
In particular, according to a further exemplary embodiment, the clamping device is arranged between the lifting element and the further lifting element. Hence, the clamping device may for example clamp a central part (first part) of the stack to the supporting table, wherein an edge part (second part) of the stack and an further edge part (further second part) of the stack, which is arranged at an opposite side of the stack with respect to the edge part, is lifted by the respective lifting elements. The stack thereby is bent, wherein the bending axis is generated in the region of the central part, so that the stack forms a U-shape.
According to an exemplary embodiment, the clamping device comprises at least one clamping element (as described above) which is movable along a clamping direction having at least one vertical component. In an exemplary embodiment, the clamping element forms a stamp element for pressing and thereby clamping the stack to the supporting table. In a further exemplary embodiment, the clamping element is mounted to the supporting table in such a way that the clamping element is movable along the clamping direction to the supporting surface of the supporting table onto which supporting surface the stack is arrangeable. The clamping element may be driven hydraulically, pneumatically or by an electronic motor.
According to an exemplary embodiment, the clamping device comprises at least one further clamping element which is movable along the clamping direction having at least one vertical component, wherein the further clamping element is spaced apart from the clamping element.
In an exemplary embodiment, the lifting device is arranged between the clamping element and the further clamping element. Hence, the lifting device may for example lift a central part (second section) of the stack away from the supporting table, wherein an edge part (first section) of the stack and a further edge part (further first section) of the stack, which is arranged at an opposite side of the stack with respect to the edge part, is clamped (pressed) to the supporting table by the respective clamping elements. The stack is again bent, wherein the bending axis is generated in the region of the central part, so that the stack forms an upside-down U-shape.
According to an exemplary embodiment, the handling system further comprises a transport device. The transport device comprises a supporting platform onto which at least a further edge portion of the stack is supportable, wherein the transport device is configured for clamping the further edge portion of the stack to the supporting platform. The transport device is movable for transporting the stack to the supporting table such that the edge portion of the stack is arrangeable onto the supporting table.
The above described transport system clamps the further edge portion of the stack by the hold down element to the supporting platform. The rest of the stack, which is not clamped by the hold down element, is arranged for example onto a carrier. By moving the transport device along a desired direction, for example perpendicular to the moving direction of the supporting table, the edge portion of the stack slips away from the carrier and can be slid onto the supporting surface of the supporting table. The carrier may therefore be higher than the supporting surface in order to provide a simple handover by sliding the edge portion from the carrier to the supporting surface.
According to an exemplary embodiment, the handling system further comprises a receiving section at which the stack is receivable. The receiving section is arranged below the supporting table and the transport device. The transport device is further movable for transporting the stack to the supporting table such that the further edge portion of the stack is arrangeable above the receiving section. The transport device is configured for releasing the further edge portion of the stack and for moving away from the receiving section such that the further edge falls down to the receiving section while the first part of the stack is clamped to the supporting table by the clamping device and the second part of the stack is lifted by the lifting device.
The receiving section may define for example a section from which the stack and the single flat elements of the stack are further processed, for example by a processing device. The processing device may be a device for processing, laminating, coating or printing of the flat elements.
For example, after the transport device pushes at least the edge portion of the stack onto the supporting surface, the transport device releases the further edge portion. The further edge portion is thereby located above the receiving section. After the transport device moves away, the further edge portion falls onto the receiving section. Alternatively, the supporting table, to which the edge portion of the stack is fixed by the clamping device and the lifting device, may move away from the transport device so that the further edge portion slips from the support platform of the transporting device.
Because the stack is bent during the fall onto the receiving section, the stack is still and robust and stiff, preventing an undesired deformation of the stack. Additionally, after the further edge portion is located onto the receiving section, the supporting table may move along a moving direction, for example from the second position to the first position, such that the location of the further edge portion onto the receiving section may be adjusted by moving the supporting table. During movement of the supporting table, the stack is still bent by the clamping device and the lifting device. Therefore, the stack is stiff and robust enough that undesired deformation during the movement of the supporting table is also prevented.
If the desired location of the further edge onto the receiving section is reached, the lifting device and the clamping device release the edge portion of the stack and in a next step, the supporting table moves away from the receiving section. The edge portion falls also onto the receiving section and the whole stack is thereby arranged in the receiving section for further proceeding.
According to third aspect of the invention, a handling system is provided for handling a stack of flat elements. The stack comprises upper and lower faces and a proximal side face mutually opposing a distal side face, the system comprising a support surface arranged to support the lower face of the stack in a region adjacent the proximal side face. The system further comprises a clamp arranged to clamp the upper surface of the stack in a region adjacent the proximal side face against the support surface. The system is further arranged to bend the stack which causes the stack to become stiffer, thereby at least partially counteracting the deflection under gravity of the stack in the area adjacent the distal side face relative to the area adjacent the proximal side face. In this aspect of the invention, the bending of the stack may be achieved in a number of ways. For example, the act of clamping the stack against the support surface may itself cause the stack to bend, where the support surface is formed with a profile that corresponds to the shape of the stack when bent. Thus, the force applied by the clamp may be used to force the stack to bend, conforming to the profile of the support surface. Alternatively, the stack may be bent by one or more a separate actuators, as described below. It will be understood that other features and advantages described with reference to other embodiments according to other aspects of the invention may also be used to advantage with respect to embodiments according to this third aspect of the invention.
Embodiments of the invention have been described with reference to different subject matters. In particular, some embodiments have been described with reference to apparatus type claims whereas other embodiments have been described with reference to method type claims. However, a person skilled in the art will gather from the above and the following description that, unless otherwise notified, in addition to any combination of features belonging to one type of subject matter also any combination between features relating to different subject matters, in particular between features of the apparatus type claims and features of the method type claims are disclosed herein.
The aspects defined above and further aspects of the present invention are apparent from the examples of embodiment to be described hereinafter and are explained with reference to the examples of embodiment. The invention will be described in more detail hereinafter with reference to examples of embodiment but to which the invention is not limited.
The illustrations in the drawings are schematic. It is noted that in different Figures, similar or identical elements are provided with the same reference signs.
The flat elements forming the stack 101 may be non-folded cartons. The first part 113 of the stack 101 defines a section of the stack 101 which contacts the clamping device 103 when the device 103 clamps the stack 101 to the supporting table 102. Specifically, the first part 113 is defined by a contact region of the clamping device 103 clamping on region a first top sheet (flat element) of the stack 101. The second part 114 defines a section of the stack 101 which contacts the lifting device 104 during lifting of the stack 101 from the supporting table 102 by the lifting device 104. Specifically, the second part 114 is defined by a contact region of the lifting device 104 with a second lower/bottom sheet (flat element) of the stack 101. In a preferred embodiment, the first part 113 and the second part 114 are defined within the edge portion 303 of the stack 101 (see
The supporting table 102 supports at least the edge portion 303 of the stack 101. The supporting table 102 comprises in particular the supporting surface 111 onto which the stack 101 is partially arranged. If the clamping device 103 does not clamp the stack 101 to the supporting table 102 (see
The clamping device 103 may comprises a clamping element, such as one or more stamps, as shown in the
The lifting device 104 comprises two lifting elements 105, 106, which are mounted to the supporting table 102 and are integrated with the supporting table 102 such that the lifting elements 105, 106 form a flat and homogeneous surface with the supporting surface (see
Before bending at the stack 101 of flat elements, the stack 101 rests on the supporting surface 111 of the supporting table 102 (see
As can be seen in
Deforming of the stack 101 around a deforming axis 110 extending within the plane 112 and differing (e.g. being perpendicular) from the above described bending axis 109 is avoided because the stack 101 is stiffer against the deformation around the deformation axis due to the U-shaped cross-section. Hence, handling the stack 101 in a bent and stiffer state reduces the risk of damaging the flat elements by reducing the risk of unintentional folding or cracking around a deformation axis.
In the exemplary embodiment, the lifting device 104 comprises in the exemplary embodiment a lifting element 105 and at least one further lifting element 106, both being movable along the lifting direction 107 which has at least one vertical component, wherein the further lifting element 106 is spaced apart from the lifting element 105.
The clamping device 103 is arranged between the lifting element 105 and the further lifting element 106. Hence, the clamping device 103 may for example clamp a central part (first section 113) of the stack 101 to the supporting table 102, wherein an edge part (second part 114) of the stack 101 and an further edge part (further second part 114) of the stack 101, which is arranged at an opposite side of the stack 101 with respect to the edge part, is lifted by the respective lifting elements 105, 106. The stack 101 is thereby bent, wherein the bending axis 109 is generated in the region of the central part 113, so that the stack 101 forms a generally U-shape.
The lifting elements 105, 106 are configured to be extendible by being pivoted around a pivot axis (see arrows in
The supporting table 102 is movable along a moving direction 301 having a horizontal component, between a first position and a second position, wherein the clamping device 103 is configured for clamping the stack 101 to the supporting table 102 during movement of the supporting table 102 between the first position and the second position. The supporting table 102 comprises roller/wheel elements 305 for moving the table along the moving direction 301. For example, the supporting table 102 may be arranged on a guiding rail, for example. In the illustrated embodiment, the clamping device 103 and the lifting device 104 are mounted to the supporting table 102 such that the clamping device 103 and the lifting device 104 move together with the supporting table 102 along the moving direction 301.
For example at the first position (shown in
The handling system 100 further comprises the transport device 308, comprising a supporting platform 309 onto which at least a further edge portion 304 of the stack 101 is supportable, wherein the transport device 308 is configured for clamping the further edge portion 304 of the stack 101 to the supporting platform 309 by a hold-down element. The transport device 308 is movable along a transport direction 310 for transporting the stack 101 to the supporting table 102 such that the edge portion 303 of the stack 101 is arrangeable on the supporting table 102.
The edge portion 303 of the stack 101 denotes a portion of the stack 101 between an edge portion and a center portion 302 of the stack 101 within a plane along which the length and the width of the stack 101 are defined. The edge portion 303 runs along an edge of the stack 101 and may have an area within the plane of ⅓ to 1/10 times or less than the area of a center portion of the stack 101. The center portion 302 of a stack 101 is surrounded by edge portions 303, 304 running along respective edges of the stack 101, wherein the edge portions 303, 304 define areas between the center portion 302 and the respective edges of a stack 101. Specifically, the edge portion 303 and the further edge portion 304 which are described herein denotes opposing edge portions 303, 304 of the stack 101.
In a preferred embodiment, the first part 113 and the second part 114 are defined within the edge portion 303 of the stack 101. The edge portion 303 of the stack 101 is initially bent by the clamping device 103 and the lifting device 104. By bending the edge portion 303, additionally the center portion 302 and the opposite further edge portion 304 are bent around the bending axis 109 as well, also if the clamping device 103 and the lifting device 104 acts onto the stack 101 only at the edge portion 303.
The further edge portion 304 of the stack 101 is clamped by the hold down element 311 to the supporting platform 309. The rest of the stack 101 which is not clamped by the hold down element 311 is arranged for example on a carrier (not shown), for example. By moving the transport device 308 along a desired direction, for example perpendicular to the moving direction 301 of the supporting table 102, the edge portion 303 of the stack 101 slips away from the carrier and can be slid onto the supporting surface 111 of the supporting table 102.
A receiving section 306 is arranged below the supporting table 102 and the transport device 308. The receiving section 306 may define for example a section from which the stack 101 and the single flat elements of the stack 101 are further processed, for example by a processing device 312. The processing device 312 may be a device for processing, laminating, coating or printing of the flat elements.
The transport device 308 along a transport direction 310 is further movable for transporting the stack 101 to the supporting table such that the further edge portion 304 of the stack 101 may be arranged above the receiving section 306. The transport device 308 is configured for releasing the further edge portion 304 of the stack 101 and for moving away from the receiving section 306 such that the further edge 304 falls down to the receiving section 306 while the first part 113 of the stack 101 is clamped to the supporting table 102 by the clamping device 103 and the second part 114 of the stack 101 is lifted by the lifting device 104.
For example, after the transport device 308 pushes at least the edge portion 303 of the stack 101 onto the supporting surface 111, the transport device 308 releases the further edge portion 304. The further edge portion 304 is thereby located above the receiving section 306. After the transport device 308 moves away, the further edge portion 304 falls onto the receiving section 306. Alternatively, the supporting table 102, to which the edge portion 303 of the stack 101 is fixed by the clamping device 103 and the lifting device 104, may move away from the transport device 308 so that the further edge portion 304 slips from the support platform 309 of the transporting device 308.
Because the stack 101 is bent during its fall onto the receiving section 306, the stack 101 is still and robust and stiff, such that a undesired deformation of the stack 101 is prevented. Additionally, after the further edge portion 303 is located onto the receiving section 306, the supporting table 102 may move along a moving direction 301 for example from the second position to the first position such that the location of the further edge portion 304 laying on the receiving section 306 may be adjusted by moving the supporting table 102. During the movement of the supporting table 102, the stack 101 is still bent by the clamping device 103 and the lifting device 104. As a result, the stack 101 is stiff and robust enough such that also undesired deformation during the movement of the supporting table 102 is prevented.
If the desired location of the further edge portion 304 on the receiving section 306 is reached, the lifting device 104 and the clamping device 103 release the edge portion 303 of the stack 101. In a next step, the supporting table 102 moves away from the receiving section 306. Furthermore, a pushing platform 307 may push the stack 101 from the supporting table 102. The edge portion 303 then falls onto the receiving section 306 and the whole stack 101 is thereby arranged in the receiving section 306 for a further proceeding.
It should be noted that the term “comprising” does not exclude other elements or steps and “a” or “an” does not exclude a plurality. Also elements described in association with different embodiments may be combined. It should also be noted that reference signs in the claims should not be construed as limiting the scope of the claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 16020037.4 | Feb 2016 | CH | national |
The present application is a 35 U.S.C. §§ 371 national phase conversion of PCT/EP2017/025024, filed Feb. 9, 2017, which claims priority of European Patent Application No. 16020037.4, filed Feb. 10, 2016, the contents of which are incorporated by reference herein. The PCT International Application was published in the English language.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2017/025024 | 2/9/2017 | WO | 00 |
