Three-dimensional structure, a blank for its production and a tab connection of the structure

Abstract

A three-dimensional structure (1) made of paper, cardboard or plastic, with at least one tab connection (2) for fixing a tab carrier (4) which is at least partially flat to a contact surface (7) in a plane-parallel fixing position, wherein the tab carrier (4) has at least one tab (8) extending in the plane of the tab carrier (4) and which, in the fixing position, penetrates a recess (9) of the contact surface (7), wherein the contact surface (7) has a contact section (12) which is pivotable or bendable about a straight bending line (11), wherein the bending line (11) runs through the recess (9) and at least one edge region (13) of the recess (9) formed in the contact section (12) is designed to be elastically deformable against a restoring force, wherein the tab (8) penetrates the recess (9) in the elastically deformed position of the edge region (13) and forms an undercut with the contact section (12), characterized in thatthat as a result of a pivoting movement (10) of the contact section (12) about the bending line (11), the edge region (13) can be placed against an end face (14) of the tab (8) and the edge region (13) can be elastically deformed and deflected by means of the end face (14) of the tab (8) forming an abutment during continued pivoting movement (10), and that in the fixing position, the contact section (12) is bent over and lies parallel to the contact surface (7), whereby the at least one tab (8) is enclosed between the contact section (12) and the contact surface (7) in the fixing position.

Description

The invention relates to a three-dimensional structure, in particular a packaging made of paper, cardboard or plastic, having at least one tab connection for fixing an at least partially planar tab carrier to a contact surface in a plane-parallel fixing position, wherein the tab carrier has at least one tab, in particular a protruding tab, which extends in the plane of the tab carrier and penetrates a recess of the contact surface in the fixing position, wherein the contact surface has a contact portion which can be pivoted or bent about a bending line, in particular impressed, formed into the paper, the cardboard or the plastic and is designed, for example, as a grooving, according to the preamble of the main claim. The invention further relates to a blank for producing the three-dimensional structure and to a tab connection.In the production of three-dimensional structures from a flat blank, it is already widely known to realize the fixing of different surface sections by means of a so-called plug-in tab, in which the tab engages in a recess and is thus secured at least against a transverse displacement. The displacement counter to the joining direction is avoided by an additional securing or counter-plate.In a transport aid made of cardboard according to DE 20 20 2017 100 554 U1, an edge-side projection is formed by a plurality of angled portions connected by score lines. The edge region of the outer bend has a plug-in tab which engages in a plug-in slot in the bend.DE 20 2018 005 756 U1 describes a foldable automatic carton in which bottom wall flaps are connected by plug-in flaps that are inserted into matching plug-in flap slots.DE 20 2017 104 977 U1 discloses a carton and a blank which comprises a plurality of side faces which are connected to one another by way of score lines, while a bottom flap is connected to a plug-in flap by way of a score line.A folding carton according to DE 10 2018 118 248 A1 has a pivotably mounted stabilizing tab on the underside of the carton front wall. The carton bottom has a pocket for securing the unfolded state.DE 20 2021 106 091 U1 describes a cardboard box with side walls, wherein an outwardly projecting plug-in flap can be inserted into a slot of an opposite side wall.EP 1 466 845 A1 discloses a wrapper made of paper or cardboard with longitudinally folded flaps which can be folded over inwards, wherein a closure section has a plug flap which can be inserted into a slot.EP 3 222 544 A1 relates to a folding box made of cardboard, in which a bottom shell and a lid shell are connected to one another such that they can be pivoted via a folding line. A push-in tab protrudes from the upper edge of a bottom side wall and has a first locking element with a cut-out in a lid side wall and at least one second locking element.CN 1 05 813 944 B already describes a paper product which, in the state of use, forms a tray-shaped container. A locking receiving section receives a locking nose of a locking section. Between a bottom surface and a side surface, a receiving section protrudes into the container interior in the region of a fold line. The locking nose, during folding, meets this locking receiving section with its end face in order to form an undercut.It has proven disadvantageous in the prior art that the use of tab connections, in particular plug tab connections, cannot ensure reliable fixing without an additional securing means, for example in the form of a counter or securing tab.The invention is based on the object of creating a snap-in tab connection that is reliable even under load on the three-dimensional structure without an additional securing means. Furthermore, the object of the invention is to create a blank and such a plug-in tab connection.The first-mentioned object is achieved according to the invention with a three-dimensional structure made of paper, cardboard or plastic according to the features of claim 1. The further embodiment of the invention can be taken from the dependent claims.According to the invention, a three-dimensional structure is thus provided in which, as a result of a pivoting movement of the contact portion about the bending line, the edge region can be placed or abuts against an end face of the tab and, during a continued pivoting movement, the edge region can be elastically deformed and deflected out of the plane of the contact portion by several millimeters, in particular between 1 mm and 5 mm or between 2 mm and 3 mm, by means of the end face of the tab forming an abutment, and in that, in the fixing position, the contact portion is bent over and lies parallel to the contact face, as a result of which the at least one tab is enclosed between the contact portion and the contact face in the fixing position.The invention is based on the surprisingly simple finding that the additional securing of the tab, which is designed as a simple plug tab and can be released from the recess without further securing against the joining direction according to the state of the art, can be dispensed with if the tab in the recess forms a self-locking undercut with the edge region. In order to achieve the undercut fixing position, only a simple pivoting movement of the contact section is required. Since the pivot axis of the contact section is determined by the straight bending line which runs through the recess, the edge region meets the end face of the tab during the pivoting movement. Since the forces acting in this case act with a substantial force component in a direction orthogonal or perpendicular to the end side of the tab and thus in the direction of the main insertion of the tab and the tab carrier, the comparatively high deformation resistance of the tab and the tab carrier leads to the edge region of the cutout being deformed, while the tab is not subject to any substantial deformation or deflection. The deformation produces a sufficient free space for the passage of the tab, which free space is blocked in the undeformed state of the edge region, so that the tab thereby reaches the rear side of the contact surface and forms an undercut.According to the invention, the tab does not become detached from the recess, for example, during a pivoting movement of the contact section in the opposite direction. Rather, the different relative orientation of the tab with respect to the edge region of the cutout in the fixing position compared to the starting position before fixing leads to no corresponding deformation force acting on the edge region. The tab can therefore not be released from the recess without an additional external force effect. Thus, although the tab connection remains releasable and only requires the pivoting of the contact section during the production of the fixing position, an additional manual intervention during the release of the tab from the fixing position by a return pivoting movement in order to deform the edge region and optionally also the tab, so that the tab connection is not accidentally released. A counter-strap known from the prior art for securing the strap is therefore unnecessary. In addition, the tab connection according to the invention has proven to be particularly easy to handle during use, because the tab connection is formed by folding or bending over the contact section and does not require a separate engagement. The tab carrier and the contact surface can be any desired surfaces, in particular wall surfaces, bottom surfaces or lid surfaces of a three-dimensional structure, for example a cardboard box.A particularly advantageous embodiment of the structure according to the invention is achieved in that each bracket carrier has a plurality of brackets arranged in the same plane, which may preferably have corresponding dimensions. This substantially improves the fixing, in particular the load-bearing capacity of the tab connection thus produced. Since the bending line runs through all the recesses assigned to the respective different lugs, these are simultaneously fixed by the undercut in the recess, so that accordingly no additional effort arises in the fixing of the lug connection.A particularly expedient embodiment of the present invention is also achieved in that the tab carrier is formed by a planar angled portion of a first wall surface and the contact surface is formed by a planar second wall surface of the three-dimensional structure, wherein the first and the second wall surface enclose an acute angle, in particular a right angle, in the position of use. By connecting different wall surfaces by means of the tab connection, complex three-dimensional structures, in particular packaging made of cardboard or paper, can also be produced in this way in a very short time without an additional adhesion connection being required. The three-dimensional structure is thus produced by a plurality of contact sections being successively bent or folded over along the respective bending line, wherein the tab connection according to the invention is produced quasi automatically without an additional intervention. Consequently, after the three-dimensional structure has been built up, additional fixing is no longer necessary, which applies both to open and to closed three-dimensional structures or three-dimensional structures which can be closed by a cover. In the context of the present invention, a panel is understood to mean any outer or inner panel or a panel section including insert or separating panels, which can form, for example, panel, base or lid panels in the structure produced.It has a particularly advantageous effect that the tab connection can also be used in the case of those wall surfaces of the three-dimensional structure which are to be connected which are not connected at a right angle, so that a wide variety of design possibilities are available. For example, the three-dimensional structure can be designed as a bumper cardboard with a central part and two rectangular or trapezoidal side parts which are oriented at an obtuse angle to the central part.According to a further embodiment of the invention promising particular success, the bending line is formed by a grooving, in particular a double grooving, as a result of which the pivoting movement can already be determined structurally and undesired changes by the user, which can lead to a defective connection, are avoided. In addition, by configuring the bending line as a double grooving, the restoring force counteracting the pivoting movement can be further reduced, which is especially advantageous also in the case of wall surfaces which require a pivoting movement of more than 90°.The deformation of the edge region of the recess in the tab connection can be promoted by the selection of the material used. In contrast, it is particularly advantageous if the edge region of the cutout extends in the direction of the contact surface between a base line and a lateral line which is at a maximum distance from the base line. In this case, the base line delimits the maximum width and the lateral line delimits the minimum width of the cutout. The clearance of the edge region achieved in this way creates a further bending line, in particular along the base line, about which the edge region can correspondingly elastically deform in order to form the desired undercut as a result of the restoring movement.In this case, the bending line between the base line and the lateral line runs in particular parallel to the base line, such that the base line and the lateral line are arranged in the plane of the contact surface on different sides of the bending line. As a result of the pivoting movement defined in this way, the end face of the tab strikes the edge region during the pivoting movement, wherein the distance from the base line and the distance from the lateral line can be dimensioned to be identical or different. The distance relationships can be adapted accordingly in accordance with the material selection and the geometric relationships, in particular the size of the tab.The edge region can be rectangular or prismatic in its basic shape, for example. Particularly preferably, the edge region of the cutout is designed convex, in particular arcuate, and in this case follows in particular a continuous course between the base line and the lateral line, in order thus to largely avoid possible damage, for example cracks. Of course, a combination of several basic geometric shapes or several different shapes combined in a tab can also be realized.By the contact section of the contact surface being pivotable about the bending line by more than 90°, prismatic three-dimensional structures can also be created which enclose an acute angle in the interior, in particular of less than 60° or less than 45°, wherein, unlike in the prior art, adhesion connections can be dispensed with.In order to reliably achieve the self-locking undercut of the tab in the recess, a restoring force of the edge region is used according to the invention. The tab and / or the tab carrier preferably consists of a dimensionally stable or bendable material, wherein the three-dimensional structure can also be produced from different materials in different regions.The second-mentioned object of creating a blank for producing the three-dimensional structure is achieved according to the invention in that the blank has at least one planar tab carrier and a contact surface for plane-parallel contact of the tab carrier, wherein the tab carrier has at least one tab, which extends in particular protrudes, in the plane of the tab carrier and passes through a recess of the contact surface in the fixing position, wherein the contact surface has a contact portion which can be bent about a straight bending line which is formed in the blank, in particular impressed, wherein the recess is bounded by an edge of the contact surface and at least one edge region of the recess is formed opposite the contact portion of the tab or the tab carrier, wherein the straight bending line runs through the recess and the edge region of the recess which extends into the recess is configured to be elastically deformable against a restoring force.This achieves a self-locking tab connection for the first time in that the blank already has all the elements required for securing the three-dimensional structure in the assembled position and no additional securing means, such as adhesion connections, are required. The recess is dimensioned such that, with respect to the relative angular position of the tab with respect to the contact portion, during the pivoting movement about the bending line, it limits an initially insufficient passage for the tab and can only penetrate the recess as a result of the deformation counter to the restoring forces of the edge region. This deformation results directly during the construction of the three-dimensional structure by the folding-up of the blank as a result of a bending along the bending line, wherein the end face of the tab and the edge region of the cutout, which in the lying position lie in a plane as a blank, meet one another, so that the edge region is deformed.Furthermore, the object according to the invention is also achieved with a tab connection by means of which a planar tab carrier is fixed on a contact surface in a plane-parallel fixing position, wherein the tab carrier has at least one in particular projecting tab which extends in the plane of the tab carrier and passes through a recess of the contact surface in the fixing position, wherein the contact surface has a contact portion which can be pivoted about a straight bending line which is formed in particular embossed into the three-dimensional structure, wherein the recess is bounded by an edge of the contact surface and at least one edge region of the recess is formed opposite the contact portion of the tab or the tab carrier. Since the axis of the bending line runs through the recess and the edge region of the recess extending into the recess is designed to be elastically deformable counter to a restoring force, as a result of a pivoting movement of the contact portion about the bending line, the edge region abuts against an end face of the tab and is thereby elastically deformed, such that the edge region is deflected during a continued pivoting movement by means of the end face of the tab forming an abutment, and the tab in the deflected position penetrates the recess and forms an undercut with the contact portion.The invention allows various embodiments. To further clarify its basic principle, one of these is illustrated in the drawing and is described below in each case on the basis of a perspective illustration. This shows in FIG. 1 shows a flat blank of cardboard; FIG. 2 shows a three-dimensional structure produced from the blank according to FIG. 1 ; FIG. 3 shows an enlarged illustration of an unlocked tab connection of the three-dimensional structure; FIG. 4 is an enlarged view of the closed tab connection; FIG. 5 shows a detail view of a recess of the tab connection.A three-dimensional structure 1 according to the invention made of cardboard with at least one tab connection 2 is explained in more detail below with reference to FIGS. 1 to 5. In order to transfer a planar blank 3 shown in FIG. 1 into the three-dimensional structure 1 shown in FIG. 2 and to fix it accordingly, a plurality of tab carriers 4 are used which are produced by a right-angled bent portion of a first wall surface 5 serving here as a base surface. By connecting this first wall surface 5 to a second wall surface 6 serving as a contact surface 7 in a predetermined angular position by means of the tab carrier 4, the desired spatial shape is defined by the relative position and orientation of the wall surfaces 5, 6 by the resulting contact surface between the wall surfaces 5, 6.Unlike in the case of three-dimensional structures from the prior art, the wall surfaces 5, 6 are not connected by an adhesion connection in the region of this contact surface 7, but by two tabs 8 designed as plug-in tabs. The tabs 8 are designed as an extension projecting on the edge side in one piece with the tab carrier 4, so that the tab 8 and the tab carrier 4 lie in the same plane.In order to secure the plane-parallel fixing position of the plate carrier 4 on the contact surface 7, it is provided that each plate 8 is inserted into a corresponding recess 9 of the contact surface 7 in order to penetrate the latter and to prevent an undesired displacement of the plate carrier 4 relative to the contact surface 7. It is obvious that the mere insertion of the tab 8 into a recess 9, regardless of the possible design, for example in a slot shape, does not allow a secure connection if no additional measure prevents a return movement counter to the joining movement of the tab 8. For this purpose, counter plates are often used in the prior art.According to the invention, such additional securing elements can be dispensed with in that the tab 8 is secured by a pivoting movement 10 of a contact section 12 of the contact surface 7 which can be pivoted about a straight bending line 11 and is locked against a restoring movement. This effect essential to the invention is realized in that the bending line 11 runs between the contact section 12 and the contact surface 7 through the recess 9. As a result, during the pivoting movement 10 of the contact section 12, that edge region 13 which lies in this contact section 12 is also pivoted about the bending line 11, as a result of which this edge region 13 collides with an end face 14 of the respective tab 8. However, this does not block the further pivoting movement 10. Rather, the edge region 13 concerned is elastically deformed counter to its material-dependent restoring force, while the tab 8 retains its original, planar shape unchanged. In particular, the load capacity of the tab 8 in the direction of its main extension, i.e. perpendicular to its end face 14, is much greater than the load capacity of the edge region 13 on which the tab 8 acts at least approximately perpendicular to the main extension. The edge region 13 is thus deformed as a result of a continued pivoting movement 10 of the contact portion 12 until the tab 8 slides along the deformed edge region 13, penetrates the cutout 9 and finally assumes its end position on the rear side of the contact portion 12.The tab 8 can accordingly pass into the recess 9 exclusively in the elastically deformed position of the edge region 13 and forms the desired undercut there with the contact portion 12, but at the same time the deformed edge region 13 bears against the tab 8 as a result of its restoring force. The clamping action exerted thereby secures the tab 8 in a force-fitting manner against a restoring movement of the tab 8 out of the recess 9. In this fixing position, the contact portion 12 is preferably completely bent and lies parallel to the contact surface 7, whereby the tab 8 is enclosed between the contact surface 7 and the contact portion 12. As a result, the tab 8 is additionally protected against an external force effect. A flat contact of the tab 8 with the bent-over contact portion 12 is not important for securing the fixing position, because this is already produced by the clamping effect of the edge region 13.For the securing function, the elastic deformation of the edge region 13 is essential, which can be further improved by a suitable geometry of the edge region 13. For example, instead of a straight boundary line 15, the edge region 13 can have a convexly shaped boundary line 16, which is only shown by dashed lines, so that the edge region 13 of the recess 9 extends between a base line 17 and a lateral line 18 at maximum distance from the base line 17. The bending resistance is reduced by this exposure of the edge region 13. In this way, the holding force of the tab connection 2 can be optimally adapted to the respective intended use. A comparable effect can also be achieved, for example, by lateral incisions or groove-shaped recesses.

Claims

A three-dimensional structure (1) made of paper, cardboard or plastic, having at least one tab connection (2) for fixing a tab carrier (4) which is planar at least in sections to a contact surface (7) in a plane-parallel fixing position, wherein the tab carrier (4) has at least one tab (8) which extends in the plane of the tab carrier (4) and which, in the fixing position, penetrates a cutout (9) of the contact surface (7), wherein the contact surface (7) has a contact portion (12) which can be pivoted or bent about a straight bending line (11), wherein the bending line (11) runs through the cutout (9) and at least one edge region (13) of the cutout (9) formed in the contact portion (12) is designed to be elastically deformable counter to a restoring force, wherein the tab (8) penetrates the recess (9) in the elastically deformed position of the edge region (13) and forms an undercut with the contact portion (12), characterized in that, as a result of a pivoting movement (10) of the contact portion (12) about the bending line (11), the edge region (13) can be placed against an end face (14) of the tab (8) and the edge region (13) can be elastically deformed and deflected by means of the end face (14) of the tab (8) forming an abutment during the continued pivoting movement (10), and in that, in the fixing position, the contact portion (12) is bent and lies parallel to the contact face (7), as a result of which the at least one tab (8) is enclosed between the contact portion (12) and the contact face (7) in the fixing position.Structure (1) according to Claim 1, characterized in that the tab carrier (4) is formed by a bent portion of a first wall surface (5) and the contact surface (7) is formed by a second wall surface (6) of the three-dimensional structure (1).Structure (1) according to at least one of the preceding claims, characterized in that the first wall surface (5) and the second wall surface (6) enclose an acute angle, in particular a right angle, in the fixing position.Structure (1) according to at least one of the preceding claims, characterized in that the bending line (11) is formed by a grooving, in particular a double grooving.Structure (1) according to at least one of the preceding claims, characterized in that the edge region (13) of the cutout (9) extends between a base line (17) and a lateral line (18) at maximum spacing from the base line (17).Structure (1) according to at least one of the preceding claims, characterized in that the bending line (11) runs between the base line (17) and the lateral line (18), in particular parallel to the base line (17).Structure (1) according to at least one of the preceding claims, characterized in that the edge region (13) of the recess (9) is formed convexly, in particular arcuately.Structure (1) according to at least one of the preceding claims, characterized in that the contact section (12) of the contact surface (7) is pivotable about the bending line (11) by more than 90°.Tab connection (2) of a three-dimensional structure (1) according to at least one of the preceding claims.Blank (3) for producing the three-dimensional structure (1) and / or a tab connection (2) according to at least one of the preceding claims.

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