Patent Description:
A converting machine can be used for producing individual sheet elements from a substrate in sheet or web form. In a related process, the substrate can be printed and die-cut to form individual printed sheet elements, each with a unique motif.

One example of such sheet elements is a set of playing cards, where each card defines a sheet element. After printing and die-cutting, the sheet elements are arranged in rows and columns and are to be stacked to form decks. In a conditioning section of the converting machine, these sheet elements may initially travel in the rows and columns and then overlap on top of each other to form the final complete set.

Document <CIT> discloses a stacking device for assembling cards into decks. Partial decks are deposited into small recipients having a geometry allowing moving fingers to move across the recipients and push one partial deck over the other to form a single deck.

Another example of a stacking device is disclosed in document <CIT>. The device is configured to transversely move adjacent cards so they become positioned on top of each other and to form a pile.

Document <CIT> discloses a device for collating a plurality of sheets. The device comprises a main transportation conveyor and a plurality of transverse feed means arranged at an angle with the main conveyor. The sheets from the transverse feed means intercept the conveyor at selected locations such that a stack of superposed sheets is created.

Document <CIT> discloses a stacking device for sheet-like products.

A supply of individual spaced-apart sheets is transformed into batches of overlapping sheets along a flow path. The device further comprises a stack merger apparatus which is configured to convert a plurality of parallel lanes of stacks traveling along the flow path into a single stream of stacks.

It is an object of the present invention to provide a stacking device for generating decks of sheet elements which is able to reliably stack sheet elements at high speed without a risk of jams of the sheet elements.

The invention provides a stacking device for generating decks of sheet elements, the stacking device comprising.

The guide is inclined with respect to the transport direction. Hence, the guide extends across in an inclined manner as seen in a top view of the stacking device.

"Upstream" and "downstream" are used with respect to stacking direction S. "Rear" and "front" are used with respect to transport direction T.

Preferably, a plurality of sheet elements are located on the first sheet section and a plurality of sheet elements are located on the adjacent second sheet section, each plurality of sheet sections forming a partial deck, and wherein the displacement element is configured to shift the partial deck on the first sheet section onto the partial deck on the adjacent second sheet section.

The partial decks of one column may form a common deck. Hence the "common deck" is a complete set of sheet elements. Such a common deck may include all playing cards in one full deck.

A sheet element and the input of the stacking device may be already made of several sheets, for example forming a sub-deck of playing cards, which is called here a "sheet element" and which has a given sheet thickness. The height offset between the sheet sections must be at least as large, but preferably larger than the sheet thickness.

In order to guarantee stacking in a given sequence and in order to avoid suction tools for handling sheet elements for stacking purposes, the present invention uses a transport device with a specific, profiled upper side. The specific profile extending along the stacking direction allows to shift the sheet element positioned on a higher sheet section onto the adjacent sheet section having a lower sheet section. This shifting is achieved by a displacement element being moved across the upper side of the transport device. preferably the profiled upper side of transport device is the same across rows which facilitates production of the profile of the upper side.

Stop protrusions can be provided to define the front ends of the sheet sections. This allows to perfectly align the sheet elements which contact the stop protrusions with their front edge. Stop protrusions are preferable perpendicular to the surface of the upper sheet section that is in contact with the lowermost sheet element.

Preferably, the sheet sections are sloped in the stacking direction. The slope may be upwardly sloped in the stacking direction. This ensures an uninterrupted contact of the sheet stacks with the ends of the sheet section during the shift along the stacking direction, so they are not rotated during their sideward shift movement. Preferably, the slope may be between <NUM>% and <NUM>%, for example <NUM>%, with respect to the horizontal. The front end of each sheet section being lower than its rear end. The tilting is particularly suited when a single displacement element of cylindrical shape is used to shift the sheet stacks sideward.

The stop protrusion or stop protrusions of one column may be extending or provided in a linear arrangement. This ensures a guiding of the sheet elements stacks during the shift along the stacking direction.

The stop protrusion or protrusions can be integrally connected to the part defining the upper side of the transport device or can be a separate part attached to the part defining the upper side of the transport device.

At least one displacement element can be associated with each column, i.e. the at least one displacement element shifts the sheet elements of one column onto each other.

In an embodiment, the guide can be a linear guide and can extend in an angular range of <NUM>-<NUM>°, more specifically in a range of <NUM>-<NUM>° with respect to the transport direction.

In an embodiment, the guide forms part of an endless, loop track. This provides a reliable mechanism for the drive of the displacement elements. Within this track, a driven push or pull means like a belt, chain or cable can be located. Displacement elements are attached to the push or pull means.

The track can have a triangular shape with rounded corners, wherein one side (the guide) extends across the upper side of the transport device inclined to the transport direction. The other sides can extend perpendicular to the end in transport direction.

The displacement element or elements preferably extend from above to a position below the sheet sections. In such a way, any gap can be avoided between the upper side of the sheet sections and the lower end of the displacement elements.

The sheet sections may comprise at least one lateral groove into which the displacement element protrudes. This helps to avoid the above-mentioned gap. The lateral groove can extend along the stacking direction. The stacking direction is preferably perpendicular to the transport direction.

In an embodiment, at least two displacement elements can be provided for each column. Each of the displacement elements can have a single, associated groove in the sheet sections of a column. This has an effect of contacting the sheet elements safely so they are not rotated during their sideward shift movement. As an alternative to the two displacement elements, a single displacement wide element with a width of at least <NUM>% of the sheet length can be provided.

The displacement elements of each column can be affixed to a common carrier guided by the guide. This ensures a sufficient stability of the displacement elements.

The transport velocity of the sheet sections in transport direction corresponds to the velocity (more precisely to the components of the velocity) of the displacement element in the transport direction. This ensures that the relative movement between the displacement element or elements and the sheet elements is a pure lateral movement directed perpendicular to the transport direction.

The transport device can be an endless track forming a loop. This endless track can be formed e.g. by an endless belt, an endless chain or an endless cable or a plurality of these elements, driven by driving and deflecting rollers.

Profiled transport blocks define the upper side of the transport device. These profiled transport blocks are attached to each other.

According to one embodiment, an endless, flexible push or pull element, e.g. an endless belt, chain or cable is provided, and the transport blocks are attached to the corresponding endless push or pull element.

According to another embodiment, the transport blocks are immediately attached to each other by a rotational axis in order to define an endless chain.

It is advantageous that the transport blocks are not rigidly connected to each other as they have to move or swivel downwardly at the end of the upper side of the transport device when reaching the final deflecting or driving roller. In this manner the transport block after having released its sheet elements can be moved underneath the table-like upper side. It is then moved in the counter-transport direction towards the deflecting roller at the front end of the transport device where it is moved upwardly to define part of the upper side again.

A dispatching device, i.e. an endless belt, is arranged adjacent to the edge of the transport device associated to the lowermost row of sheet sections. The displacement elements are arranged so as to shift the decks onto the adjacent dispatching device which removes the decks from the stacking device.

The present invention also provides a transport block for the stacking device according to the invention. The transport block has a profiled upper side and an opposite lower side. The profiled upper side has a plurality of sheet sections configured to receive sheet elements to be arranged thereon, and wherein said height offset is provided in the stacking direction between adjacent sheet sections.

The transport block has a front and rear end, the front end comprising a stop protrusion protruding above the sheet sections and/or the transport block has at least one groove at its upper side extending parallel to the front end.

The transport block can be molded from plastic material.

In <FIG>, a stacking device for generating decks <NUM> of sheet elements <NUM> made of paper, cardboard (including corrugated board) or plastic is shown.

The stacking device comprises a transport device <NUM> which is an endless track comprising a push or pull means as an endless belt <NUM> (see <FIG>) which is driven by one or more rollers <NUM> and is partly wound around deflecting rollers.

Instead of an endless belt <NUM>, a chain or one or more endless cables can be provided. Thus, whenever the term "endless belt" is used in the following, chains, cables etc. can be used instead of an endless belt <NUM>.

Several elongate transport blocks <NUM> are attached to the outer side of the endless belt <NUM> (see <FIG> and <FIG>).

The endless belt <NUM> is driven in a transport direction T (see <FIG> and <FIG>).

The transport blocks <NUM> may be arranged with their longer side coinciding with the transport direction T. Alternatively, in a non-illustrated embodiment, the longer side of the transport blocks may be aligned perpendicular to the transport direction T.

Each transport block <NUM> has a front end <NUM> and a rear end <NUM> which are parallel to each other and to the stacking direction S and perpendicular to transport direction T.

Furthermore, each transport block <NUM> has a first longitudinal edge <NUM> upstream (here the left hand edge seen in transport direction T) and an opposite edge <NUM>. The edges <NUM> and <NUM> of all blocks <NUM> define the longitudinal edges of the transport device.

A displacement device <NUM> is arranged above the upper side of the transport device. The "upper side" is defined by all transport blocks <NUM> protruding upwardly from the endless belt <NUM>, i.e. having their upper side being directed upwardly. As endless belt <NUM> is been moved together with its transport blocks <NUM> some transport blocks <NUM> are facing downwardly and some upwardly.

Displacement device <NUM> comprises an endless, loop track <NUM> which guides and drives displacement elements <NUM> (see <FIG>).

In an embodiment, one single displacement element <NUM> is attached to a carrier <NUM>, or directly to an endless push or pull element <NUM>, e.g. a chain, endless belt or cable which is moved along track <NUM>. The displacement element <NUM> is placed preferably in the middle of each sheet element longitudinal side, so that the sheet element is not rotated during its sideward shift movement. This embodiment allows the carrier <NUM> to freely rotate around the vertical axis, resulting in a simpler system. In another embodiment, two displacement elements <NUM> are attached to a carrier <NUM> in order to form a fork-like body. Carrier <NUM> has a pin <NUM> (see <FIG>) which protrudes into track <NUM> in which an endless push or pull element, e.g. a chain, endless belt or cable is moved. Pin <NUM> is coupled to sliders within guide track <NUM> which are attached to the push or pull element. As a drive for moving the endless push or pull element a motor with a gear or friction roller engaging the push or pull element can be used. In this embodiment, the orientation of the carrier <NUM> along the vertical axis must be fixed, thus the guide <NUM> must be arranged to control the orientation of carrier <NUM>.

Linear guides that are arranged to control the orientation of the guided element, or that let the orientation of the guided element free are well known in the art. <FIG> shows an example of a guide <NUM> that controls the orientation of the carrier <NUM>, whereas <FIG> shows an example of a guide where the orientation of the carrier is not well controlled, but which is simpler to implement.

<FIG> shows a guide <NUM> with two inner grooves <NUM>. A guided carrier <NUM> comprising three wheels with ball bearings and with an outer profile <NUM> adapted to engage into groove <NUM>. When engaged into the groove <NUM> with its three wheels <NUM>, the guided carrier <NUM> has a single degree of freedom, resulting in the control of the orientation of the displacement element(s) <NUM> attached below. The guided carrier <NUM> is connected to and transported by an endless push or pull element <NUM>, e.g. a chain, endless belt or cable, which moves the guided carrier along guide <NUM>. The endless push or pull element car be placed in-between the guided carrier <NUM> and the displacement element(s) <NUM>, as shown in <FIG>, or above the guided carrier <NUM>. <FIG> shows a guide <NUM> with a groove <NUM> in which a guided carrier <NUM> engages. The engagement of the guided carrier <NUM> into the groove <NUM> fixes the orientation along direction V of the displacement element <NUM>, to ensure a proper alignment of the stacks of sheet elements along stacking direction S. The guided carrier <NUM> is transported by an endless push or pull element <NUM>, e.g. a chain, endless belt or cable, along guide <NUM>.

Track <NUM> has a triangular shape with two sides arranged perpendicular to each other. The first side extends parallel to transport direction T and the second side perpendicular thereto. A third side which is termed "guide" <NUM> extends at an angle across the upper side (see <FIG>).

Guide <NUM> may extend at an angle α of <NUM>-<NUM>°, more particular <NUM>-<NUM>° with respect to the transport direction T, across the upper side of the transport device (see <FIG>).

Guide <NUM> extends linearly from an rear end <NUM> at the left hand side longitudinal edge to a front end <NUM> at the right hand side longitudinal edge.

As can be seen from <FIG>, <FIG> and <FIG>, carriers <NUM> are aligned in different angles with respect to the portion of the track <NUM> at which they are positioned. Along guide <NUM>, carriers <NUM> are arranged inclined to longitudinal direction T of guide <NUM>, whereas in the remainder of track <NUM> carriers <NUM> are arranged in track direction. Deflector elements or drive elements are provided to align carriers <NUM> correspondingly.

As can be seen from <FIG>, numerous sheet elements <NUM> are distributed over the upper side of the transport device in rows R (aligned in transport direction T) and columns C (aligned in stacking direction S). The plurality of transport blocks <NUM> (see <FIG>) are defined by the rows R and columns C and provide sheet sections <NUM> on which the sheet elements <NUM> lie. In an embodiment, each transport block <NUM> may initially receive one sheet element <NUM>. However, in a preferred embodiment, each transport block <NUM> is configured to receive a plurality of superposed sheet elements <NUM> in the form of partial decks. In such a way, the present stacking device can stack a plurality of partial decks on top of each other and quickly form a larger complete deck <NUM>.

As the present stacking device comprises several columns C, each column C is preferably associated with at least one displacement element <NUM> (as described above). The displacement elements <NUM> are travelling along the endless loop track <NUM> and numerous displacement elements <NUM> can be distributed along the endless loop track <NUM>. The displacement elements <NUM> are preferably evenly distributed at a constant distance from each other along the endless loop track <NUM>. This ensures that there is a constant supply of displacement elements <NUM> in order to continuously engage with the sheet sections <NUM> in the columns C. Hence, this allows some displacement elements <NUM> to be in operation (i.e. moving in the columns), while others are positioned on a return path of the endless loop track <NUM>.

A device and method for creating such partial decks is described in the application<CIT>. The device in <CIT> is an upstream-located stacking device which is designed to gradually overlap, in the transport direction T, individual sheet elements <NUM> in several transportation paths (i.e. rows R) on top of each other in order to form partial decks.

In such a way, the stacking device of the present disclosure can be used further downstream of the device in <CIT> to superpose the partial decks from each column C, in a direction perpendicular to the transport direction T, such that a complete deck is created.

At the rear end, before reaching guide <NUM>, sheet elements <NUM> are arranged one by one next to each other and distanced from each other. Therefore, each sheet element <NUM> has a specific row and a specific column position.

While being transported on the upper side of the transport device in transport direction T and as soon as the upstream side sheet elements <NUM> have reached guide <NUM>, the sheet elements <NUM> of a column C are displaced beginning from the sheet element <NUM> on the upstream side, i.e. from the longitudinal edge at the left hand side in the figures, continuously towards the opposite longitudinal edge on the downstream side, i.e. a longitudinal edge on the right hand side in the figures.

Displacement of sheet elements <NUM> from upstream to downstream is achieved by displacement elements <NUM> engaging the upstream edge of the upstream side of sheet element <NUM> as can be seen in <FIG>. Each pair of displacement elements <NUM> is associated to the column C at which it starts to contact a sheet element <NUM>.

<FIG> shows that carriers <NUM> move together with their columns C of sheet elements <NUM> in transport direction. Carriers <NUM> are both moving in transport direction T and transversely thereto in stacking direction. The velocity of their movement in transport direction T corresponds to the velocity of the transport device.

As can be seen from <FIG>, sheet elements <NUM> of one column C are shifted to edge <NUM> when being moved in transport direction T by corresponding displacement elements <NUM>. Partial decks formed on one of the sheet sections <NUM> are shifted onto the sheet element adjacent thereto so that the height of the deck is permanently increasing until all sheet elements <NUM> of one column C are stacked together.

At the end <NUM> of guide <NUM> the displacement elements <NUM> shift the decks <NUM> onto a dispatching device <NUM> in the form of an endless belt. The upper side of the dispatching device <NUM> is arranged slightly underneath the lowermost sheet section <NUM> which defines edge <NUM>.

<FIG> further shows that each transport block <NUM> is associated to one, preferably one single column C. Thus, sheet elements <NUM> of one column C are positioned on the upper side of one transport block <NUM>.

In order to perfectly align sheet elements <NUM> of one column C in transport direction T, each transport block <NUM> has at least one associated stop protrusion <NUM> at its front end. <FIG> shows that the stop protrusions <NUM> are protruding over the upper side of the transport device and that the stop protrusions <NUM> of one column C are arranged in a linear line. Transport blocks <NUM> are, for example, molded plastic parts.

Stop protrusions <NUM> can be integrally formed to transport blocks <NUM> or be defined by a separate plate-like part attached to the front side of transport block <NUM> (see <FIG>).

As can be seen from <FIG>, each sheet section <NUM> is arranged with a height offset Δh in relation to an adjacent sheet section <NUM> in the stacking direction S. By travelling from upstream to downstream in the stacking direction S, every sheet section <NUM> exhibits a height offset Δh with its adjacent sheet section <NUM>. This height offset must be at least as large, but preferably larger than the sheet element thickness, in order to ensure a proper stacking of the sheet elements. In a given column C, the sheet section which is the most upstream is also referred to as the "highest" sheet section, or the sheet section at the "upper side", the one which is the most downstream is referred to as the "lowermost" sheet section, even if their respective height compared to the horizontal might be the same. This height offset Δh allows the sheet elements are shifted onto each other (as can be seen in <FIG>).

The sheet sections <NUM> of one column C have a first longitudinal edge 50A and a second longitudinal edge 50B. The second longitudinal edge 50B is located further downstream in the stacking direction S than the first longitudinal edge 50A. The second longitudinal edge 50B of the first sheet section <NUM> is located at a higher vertical position than the first longitudinal edge 50A of an adjacent second sheet section <NUM>, arranged further downstream in the stacking direction S. This provides a height offset Δh in the stacking direction S between the adjacent sheet sections <NUM>. The first longitudinal edge 50A and the second longitudinal edge 50B can be aligned with the respective edges of the sheet elements <NUM>.

In order to avoid a gap between the upper side of the transport device and the lowermost end of displacement elements <NUM>, even at the lowermost sheet section <NUM>, displacement elements <NUM> extend into an associated lateral groove <NUM> in its transport block <NUM>. Lateral grooves <NUM> extend along the full width of its transport block <NUM> so that displacement elements <NUM> can enter the lateral grooves at edge <NUM> and exit therefrom at edge <NUM>.

Claim 1:
Stacking device for generating decks (<NUM>) of sheet elements (<NUM>), the stacking device comprising
a transport device (<NUM>) with an upper side for transporting the sheet elements (<NUM>), the upper side having a plurality of sheet sections (<NUM>) configured to receive sheet elements (<NUM>) to be arranged thereon, the plurality of sheet sections (<NUM>) being arranged in rows (R) and columns (C),
wherein rows (R) are aligned in a transport direction (T) of the stacking device, and columns (C) perpendicular thereto in a stacking direction (S),
and wherein the plurality of sheet sections (<NUM>) of one column (C) comprises at least one first sheet section (<NUM>) and at least one adjacent second sheet section (<NUM>) arranged further downstream in the stacking direction (S), and wherein a height offset (Δh) is provided in the stacking direction (S) between the first sheet section (<NUM>) and the second sheet section (<NUM>), said height offset (Δh) allowing at least one sheet element (<NUM>) on the first sheet section to be moved over and be positioned on top of an adjacent sheet element on the second sheet section (<NUM>),
at least one displacement element (<NUM>) driven to be moved transverse to the transport direction (T) along the sheet sections (<NUM>) of a column (C),
the displacement element (<NUM>) engaging with the sheet sections (<NUM>) of one column (C) for shifting the at least one sheet element (<NUM>) of a first sheet section (<NUM>) onto the sheet element (<NUM>) on the adjacent, second sheet section (<NUM>), and wherein a guide (<NUM>) for the at least one displacement element (<NUM>) is arranged above the sheet sections (<NUM>), characterized in that the guide (<NUM>) extends obliquely across the upper side of the transport device (<NUM>) in the transport direction (T), such that as seen in a top view of the stacking device, the guide (<NUM>) extends across inclined with respect to the transport direction (T).