TECHNOLOGY FOR DYNAMIC LENGTH COMPENSATION

Description

[0001] The invention relates to a technique for dynamic length compensation during embossing of a foil strip.

[0002] Traditionally, foil strips (also known as foil pieces or foils for short) are used to mark prolate objects, especially conductors (also known as cables). A foil strip is wrapped (also known as applied) around the prolate object, and the free ends are welded. To wrap (also known as wrap) the prolate object, the foil strip is embossed at two predetermined lengths. For example, the distance between the two predetermined lengths can correspond to at least one circumference of the prolate object.

[0003] In Fig. 1The foil strip 10 is inserted into a conventional, straight and rigid guide channel 16 with opposite rigid sides 16-1 and 16-2. For embossing, the foil strip 10 is pressed and embossed by an embossing station 14 with an embossing die 14-1, in particular with a sharp-edged embossing blade 14-3, on a rigid side 16-1 of the guide channel into a flexible embossing pad (e.g., a rubber pad) 14-2, which is arranged on the opposite rigid side 16-2. As in Fig. 2As shown, the foil strip 10 is pulled and / or lengthened by the pressing. Conventionally, the foil strip 10 cannot compensate for the tensile force (generated, for example, by the embossing blade 14-3) because it is firmly fixed at one end under a pressure roller 12 and cannot yield. This results in mechanical stresses in the entire device used to emboss the foil strip 10 and mark the prolate object. Furthermore, neither the positions of the embossed edges of the foil strip 10 nor the lengths of the markings (also: signs or flags) conventionally correspond to a predetermined dimension for the wrapping because the foil strip 10 is pulled away in an uncontrolled manner from under the pressure roller 12 or the embossing pad 14-2.

[0004] Devices and methods of the type in question are known from the general state of the art from US 2019 / 202162 A1 as well as DE 197 48 789 A1.

[0005] Furthermore, devices of the type mentioned in the preamble of patent claim 1 and methods of the type mentioned in the preamble of patent claim 16 are known from WO 2009 / 143644 A1.

[0006] The invention is therefore based on the object of specifying a technique for dynamic length compensation during the embossing of a foil strip.

[0007] The object is achieved by the features of the independent claims. Expedient embodiments and advantageous further developments of the invention are specified in the dependent claims.

[0008] Embodiments of the invention are described below with partial reference to the figures.

[0009] According to a first aspect, a device for dynamic length compensation during embossing of a foil strip comprises an embossing point, a roller designed for slip-free transport of the foil strip (for example a printing roller and / or a transport roller), and a guide channel arranged between the embossing point and the roller. The guide channel comprises a guide surface movable between a first position and a second position. A path length of the foil strip between the roller and the embossing point in the first position of the guide surface is greater than a path length of the foil strip between the roller and the embossing point in the second position. In the first position of the guide surface, the foil strip is conveyed in the guide channel from the roller to the embossing point. The guide surface is moved from the first position to the second position during embossing of the foil strip.

[0010] The roller designed for slip-free transport of the film strip can comprise a pressure roller and / or a transport roller. Alternatively or additionally, slip-free transport can be achieved by a (for example, rough) surface structure and / or pressure exerted by the roller on the film strip, in particular approximately perpendicular to a longitudinal direction of the guide channel.

[0011] The guide channel can also be called a media path.

[0012] The guide surface can also be referred to as a movable deflection element.

[0013] The guide surface can be movable between the first position and the second position within the guide channel, preferably transversely to a course of the film strip determined by the guide channel.

[0014] The movement of the guide surface can compensate for any movement of the foil strip, particularly any stretching of the foil strip, during embossing. Alternatively or additionally, damage to the foil strip during embossing due to tensile forces can be prevented and / or minimized. The tensile forces can be exerted on the foil strip, for example, by the embossing point, particularly an embossing die and / or embossing blade.

[0015] By embossing the foil tape, the application of a marking to a prolate object can be made easier and / or improved.

[0016] Applying the foil strip can comprise arranging the foil strip in a circumferentially closed manner around the prolate object (for example, around a longitudinal axis of the prolate object in the longitudinal direction). The device can comprise a mechanism for applying the foil strip around the prolate object. For example, a mechanism for applying the foil strip can be arranged downstream of the embossing point in a conveying direction of the foil strip (i.e., a direction from the roller to the embossing point).

[0017] The foil strip can comprise a labeled and / or printed portion that, after the foil strip has been applied to the prolate object, protrudes from the prolate object as a flag and / or is readable in a plane. For example, the embossing can facilitate bonding (e.g., by plastic welding, in particular by means of ultrasound or heating) of two opposite ends of the foil strip and / or improve the readability of the printed (e.g., labeled) portion.

[0018] Alternatively or additionally, embossing can provide improved conformability of the film strip to the prolate object, with bending points defined by the embossing for bonding. Alternatively or additionally, embossing can achieve improved stability of a flag section of the film strip.

[0019] Alternatively or additionally, the embossing can cause the printed (e.g. labelled) section of the foil strip to be tangent to the prolate object and / or to be substantially flat and / or to have a (preferably many times) larger radius of curvature than the prolate object.

[0020] The guide surface may be preloaded to move from the first position and into the second position, for example by means of a spring.

[0021] The guide surface may comprise a spring. For example, the guide surface may be preloaded on or about a rotational axis (for example comprising a hinge) by a spring (for example a leaf spring, a torsion spring, or a gas spring). Alternatively or additionally, the guide surface may comprise a deformable (also: flexible) material and / or shape memory material. A rest position of the deformable material and / or the shape memory of the guide surface may comprise the first position and / or correspond to the first position. The deformable material and / or shape memory material may be attached (for example rigidly) to a rigid section of the guide channel by one end of the guide surface.

[0022] The tensile stress on the foil strip can be limited by the preload of the movable guide surface. The limited tensile stress can be smaller than the roller's holding torque (e.g., corresponding to the roller radius). This can prevent the roller from rotating during the embossing process or the foil strip from sliding over the roller during the embossing process.

[0023] The film strip can rest against the guide surface in the first position and / or in the second position (for example, at least in sections) to guide the film strip in a curved manner in the guide channel. Alternatively or additionally, the film strip can be guided in a curved manner in the guide channel in the first position and / or in the second position.

[0024] A (for example maximum) curvature of the path of the film strip determined by the guide channel along the path length can be greater in the first position than in the second position.

[0025] The guide surface can have a rotatably mounted roller over which the film strip can be guided, preferably without slippage. This minimizes friction on the film strip.

[0026] The guide surface may be convex on a side facing the film strip.

[0027] A radius of curvature of the convex guide surface can correspond (for example in sections) to the curvilinear guide.

[0028] The radius of curvature of the convex guide surface can be smaller than the path length of the foil strip guided in the guide channel. This allows a small transmission ratio between the preload of the guide surface and the limited tensile stress of the foil strip to be achieved. The preload of the guide surface can correspond to a normal force that the guide surface transmits to the foil strip perpendicular to the guide surface. The transmission ratio between the normal force of the guide surface and the limited tensile stress of the foil strip can be less than three to one (3:1) or two to one (2:1).

[0029] A radius of curvature of the convex guide surface can be many times larger than a thickness (i.e. strength) of the foil strip.

[0030] Preferably, the film strip does not slide over an edge (e.g., a bent or cut edge) of the guide surface. This can prevent damage to the film strip (e.g., detachment of a surface coating and / or a marking on the film strip).

[0031] A radius of curvature of the convex guide surface can be larger than the width of the guide channel, particularly in the first position. Alternatively or additionally, the width of the guide channel and / or the guide surface can be larger than the width of the foil strip (e.g., intended for embossing).

[0032] The width can be the width of a section of the guide channel bordered by the guide surface. This can prevent jamming of the film strip in the guide channel during transport.

[0033] The film strip can rest on the guide surface (for example, at least in sections) both in the first position and in the second position.

[0034] The guide surface can be arranged within the guide channel in both the first and second positions. This allows the tensile force to be limited by the pretension throughout the entire range between the first and second positions. In other words, the foil strip never runs in a plane, or only in the second position of the guide surface. For example, the guide surface deflects the foil strip out of a plane in the first position, and optionally in the second position. The plane can be determined by the sections of the guide channel at the roller and at the embossing point.

[0035] The guide surface can be pivotable between the first position and the second position. For example, a rotation axis (also: pivot axis, for example comprising a hinge or a bearing) of the pivoting movement can be arranged perpendicular to the film strip and / or perpendicular to the path of the film strip determined by the guide channel (i.e., the conveying direction).

[0036] A pivot point of the pivoting movement can be arranged outside the guide channel.

[0037] The embossing point can comprise an embossing die movable transversely to the guide channel and an embossing pad arranged in the transverse movement of the embossing die. The guide channel can open at the embossing point between the embossing die and the embossing pad.

[0038] The transverse movement of the embossing stamp into the embossing pad can shorten the path length of the foil strip in the guide channel, for example, counteracting a pre-tension of the guide surface.

[0039] During the embossing process, the guide surface and the stamping die can move in parallel relative to a transverse direction of the guide channel. The transverse direction can be perpendicular to the conveying direction (i.e., the course of the conveying channel) and / or perpendicular to the rotation axis (i.e., pivot axis) of the guide surface.

[0040] The movement of the guide surface during embossing may include a movement from the first position to the second position. This can reduce friction on stationary surfaces of the guide channel between the guide surface and the embossing point.

[0041] Alternatively or additionally, the guide surface and the embossing die can move in opposite directions relative to the transverse direction of the guide channel during embossing. Thus, a first side of the guide channel can comprise a drive for the embossing die and / or the rotation axis of the guide surface, and / or a second side of the guide channel, opposite the first side in the transverse direction, can be designed to be particularly compact and / or simple.

[0042] Alternatively or additionally, the guide surface and the embossing die can move in parallel with the transverse direction of the guide channel during the embossing process. This allows the foil strip, which is subjected to tensile stress (or tension for short), to slide over the guide surface with particularly low friction.

[0043] Alternatively or additionally, gravity can contribute to tensioning the film strip, particularly along the guide surface.

[0044] The embossing die can be or comprise a embossing blade. The embossing blade can preferably be perpendicular to the guide channel. Alternatively or additionally, the embossing die can comprise an edge (e.g., a pointed edge) for embossing.

[0045] According to a second aspect, a method for dynamic length compensation during embossing of a foil strip is provided. The method comprises a step of conveying the foil strip in a guide channel arranged between a roller (for example, a printing roller and / or a transport roller), which is designed for slip-free transport of the foil strip, and an embossing point. The foil strip is conveyed in a direction from the roller to the embossing point. The guide channel comprises a guide surface movable between a first position and a second position. During conveyance of the foil strip, the guide surface comprises the first position and / or the guide surface assumes the first position. The method further comprises a step of embossing the foil strip by means of the embossing point. The guide surface is moved into the second position during embossing (for example, due to increasing tensile stress on the foil strip).A path length of the foil strip between the roller and the embossing point in the first position of the guide surface is greater than a path length of the foil strip between the roller and the embossing point in the second position.

[0046] The method of the second aspect can be carried out by means of the device of the first aspect.

[0047] The invention is explained in more detail below with reference to the drawings using preferred embodiments.

[0048] They show: Fig. 1 schematically shows a comparative example of a conventional device for embossing a foil strip in a first position of an embossing die, in which the embossing die is arranged outside a static guide channel of the device; Fig. 2 schematically shows the comparative example of the conventional device for embossing the foil strip in a second position of the embossing die, in which the embossing die projects into the guide channel of the device and moves or stretches the foil strip to the left; Fig. 3 schematically shows a first embodiment of a device for dynamic length compensation during embossing of a foil strip in a first position of a guide surface, while an embossing die is arranged outside a guide channel; Fig.Fig. 4 schematically shows the first embodiment of the device for dynamic length compensation during embossing of the foil strip in a second position of the guide surface, while the embossing die protrudes into the guide channel and exerts a tensile force on the foil strip; Fig. 5 schematically shows a second embodiment of a device for dynamic length compensation during embossing of a foil strip in a second position of the guide surface, while an embossing die protrudes into the guide channel and exerts a tensile force on the foil strip; Fig. 6 schematically shows a guide surface comprising a deformable (e.g. shape memory) material and tensile forces acting on a foil strip; Fig. 7 schematically shows a wedge-shaped tip of an embossing die and a feed path of a foil strip as a function of a penetration depth of the embossing die into the embossing pad;Fig. 8 shows a further schematic embodiment of a device for dynamic length compensation during embossing of a foil strip, in which a movable guide surface comprises a lever arm; and Fig. 9 shows a further schematic embodiment of a device for dynamic length compensation during embossing of a foil strip, in which a movable guide surface comprises a spring.

[0049] The Fig. 3 shows schematically a first embodiment of a device 300 for dynamic length compensation according to the invention during embossing of a foil strip 10.

[0050] The device of Fig. 3 comprises a printing roller 302, an embossing point 304 and a guide channel 306 arranged between the printing roller 302 and the embossing point 304, in which the film strip 10 is guided.

[0051] The embossing station 304 of the first embodiment comprises an embossing die 304-1 with an embossing blade 304-3 and an embossing pad 304-2. The embossing die 304-1 and the embossing pad 304-2 are arranged on opposite sides 306-1, 306-2 of the guide channel 306.

[0052] The guide channel 306 comprises a first side 306-1 on which the embossing die 304-1 is arranged, and a side 306-2 opposite the first side 306-1 on which the embossing pad 304-2 is arranged.

[0053] In the first embodiment of the Fig. 3 a movable guide surface (also: flexible deflection element) 308 is arranged on the first side 306-1 and / or forms part of a side wall of the first side 306-1 of the guide channel 306. The guide surface 308 is in the first embodiment of the Fig. 3by means of a spring-loaded hinge 310 on a rigid part of the first side 306-1 of the guide channel 306 and subjected to a preload 312. Due to the preload 312, the movable guide surface 308 is in a rest position (for example, without tensile forces acting on the film strip 10) in the Fig. 3 shown first position. The second side 306-2 of the guide channel 306 is in the first embodiment of the Fig. 3 rigidly formed.

[0054] Fig. 4 shows the device 300 of the first embodiment schematically with the movable guide surface 308 in a second position. The second position is located between the first position 402 and a stop position 404, in which the guide surface 308 abuts the rigid part of the first side 306-1 with its free end facing away from the hinge 310. Alternatively, the second position can correspond to the stop position 404.

[0055] As in Fig. 4 As shown, the movable guide surface 308 assumes the second position when the embossing die 304-1 presses the foil strip 10 into the embossing pad 304-2.

[0056] In the first embodiment of the Fig. 3 and 4 the movable guide surface 308 is brought into the second position (in particular against the pretension 312) in the opposite direction to a movement of the stamping die 304-1 during stamping.

[0057] Fig. 5 shows schematically a second embodiment of a device 300 for dynamic length compensation according to the invention during embossing of a foil strip 10.

[0058] Identical parts of the device 300 in all embodiments are designated by the same reference numerals.

[0059] In the second embodiment of the Fig. 5The movable guide surface 308 is rotatably mounted on a rigid part of the second side 306-2 of the guide channel 306 by means of a spring-loaded hinge 310. In the second embodiment of the Fig. 5 the first side 306-1 of the guide channel 306 is rigid.

[0060] In the second embodiment of the Fig. 5 the movable guide surface 308 (in particular against the pretension 312) is brought into the second position in parallel with a movement of the stamping die 304-1 during stamping.

[0061] In a third embodiment, the movable guide surface 308 comprises a flexible (e.g., shape memory) material that is rigidly arranged at one end (e.g., instead of by means of a hinge 310) to a rigid part of the first side 306-1 or the second side 306-2 of the guide channel 306. In the third embodiment, the rest position of the flexible material and / or the shape memory biases the movable guide surface 308 in the first position 402, and in the second position 602, the flexible (e.g., shape memory) material of the movable guide surface 308 is deformed from its rest position, as schematically shown in Fig. 6 is shown.

[0062] As can be seen from the above exemplary embodiments, by introducing the movable guide surface 308 (also: the flexible deflection element) into the guide channel 306 (also: media path, in short: path), a tensile force and / or tensile movement of the embossing point 304 on the foil strip 10 during embossing can be compensated.

[0063] By means of the pretension 312 of the movable guide surface 308, the film strip 10 (for example, deflected by a flat surface) can reproducibly follow the same path, so that an absolute value of a length of the film strip 10 (also: sign length), in particular a section for wrapping a prolate object and / or a flag section for applying (for example, printing) a marking, does not fluctuate beyond a tolerance range. The tolerance range can, for example, comprise a change in the length of the film strip 10 of at most one-tenth of a millimeter (0.1 mm).

[0064] By means of a shape of the movable guide surface 308 and / or the pretension 312 of the movable guide surface 308, disturbances, for example film jams, in the deflection of the film strip 10 can be prevented.

[0065] A service life of a spring element, for example arranged on the hinge 308 of the first and / or second embodiment, and / or a service life of a deformable (e.g. shape memory) material, for example according to the third embodiment, can be selected according to a planned number of cycles, for example a number of embossing processes and / or a number of markings of the prolate object by means of the foil strip 10.

[0066] Fig. 6shows schematically a movable guide surface (also: flexible element) 308, which can be designed, for example, as a shape memory material and deforms or moves from the first position 402 to the second position 602 under a force exerted by the film strip 10.

[0067] The movable guide surface 308 can be stiff enough to guide the film strip 10 (also: the medium to be deflected). However, the movable guide surface 308 should not be stronger (for example, it should not exert a greater tensile force on the film strip 10) than the strength of the film strip 10 allows or than a clamping force that holds the film strip 10 in position (for example, a clamping force of the pressure roller, also: pressure roller, 302). Otherwise, the film strip 10 may slip, particularly over the movable guide surface 308. This may result in the loss of a desired effect, particularly the dynamic length compensation.

[0068] In Fig. 6A pressing force (for example, comprising friction of the foil strip 10 on the printing roller 302) 604 is shown schematically, which effectively exerts a holding force F1 on the foil strip 10 guided by the printing roller 302 in the direction of the embossing point 304. A magnitude of the pressing force and / or the friction can be determined by a friction coefficient of the printing roller 302 and / or a friction coefficient of the foil strip 10.

[0069] A stiffness of the movable guide surface 308 and / or an angle (for example, in the first position 402 and / or the second position 602) of the movable guide surface 308 can generate a required tensile force to deflect and / or deform the movable guide surface 308.

[0070] A tensile force F2, as shown schematically at reference 606, may be (in particular much) smaller than the holding force F1 at reference 604, F2 < F1 (in particular F2 << F1).

[0071] In the embodiment in Fig. 6 The embossing die 304-1 includes a wedge-shaped end that can press the foil strip 10 into the embossing die 304-2 and / or emboss the foil strip 10. Alternatively or additionally, a wedge-shaped end of the embossing die 304-1 can also be referred to as an embossing blade.

[0072] Fig. 7 shows an example of a wedge-shaped end 304-1 of an embossing die 304-1. In the exemplary embodiment, the wedge shape comprises an angle 708 of 60 degrees. Alternatively or additionally, a cross-section of an embossing blade 304-3 comprises an equiangular triangle.

[0073] In the embodiment of the Fig. 7The wedge-shaped end 304-1 comprises a height 702, which can correspond (e.g., approximately) to a penetration depth of the embossing die 304-1 into the embossing pad. For example, a (e.g., proper or correct) embossing can comprise a penetration depth of one to two millimeters (in particular, approximately 1.5 mm) of the embossing die 304-1 (e.g., the embossing blade 304-3) into the embossing pad 304-2.

[0074] The height 702 in the equiangular triangle is the 3 / 2 times the side length 704. In the example of a height of 1.5 mm, the side length corresponds to approximately 1.73 mm and half the side length 706 corresponds to approximately 0.87 mm.

[0075] The penetration depth of the embossing die 304-1 results in an additional feed path (which can also be referred to as "delta") of the foil strip approximately corresponding to half the side length 706, for example, 0.87 mm additional feed path. The additional feed path can refer to a change in the length of the foil strip 10 between the wedge-shaped end and / or the embossing blade 304-3 at one end of the guide channel 306 and a pressure roller at the other end of the guide channel, as exemplified by reference numeral 706 in Fig. 7 shown.

[0076] Preferably, the guide channel 306 is longer by the feed path, for example half the side length 706, in the first position 402 of the guide surface 308 than in the second position 602 of the guide surface 308.

[0077] The first position 402 of the guide surface 308 can also be referred to as the formation of a chicane.

[0078] A change in the length of the guide channel 308 from the first position 402 to the second position 602 may be dependent on a depth of the embossing and / or correspond to the depth of the embossing.

[0079] The dynamic length compensation, for example with a predetermined tolerance range and / or a deviation of a length of the foil strip 10 by less than one millimeter (in particular in the range of 1 / 10 mm or less), during embossing can be achieved by moving the movable guide surface 308 from the first position 402 to the second position 602. For example, the length compensation can be made possible by selecting a length of a (in particular rigid) guide surface 308 around a rotation axis (for example determined by a hinge 310) and / or by selecting an elasticity of a (for example shape memory) material.

[0080] The guide surface 308 can comprise polyester (e.g. Hostaphan) and / or a spring steel sheet as material.

[0081] The film strip 10 can comprise a plastic tape for welding, a self-adhesive tape, a carrier for adhesive labels and / or insertable labels. Alternatively or additionally, the film strip 10 can comprise a heat-sealing film (e.g., a polyester laminate and / or hot-melt adhesive) as a material.

[0082] The foil strip 10 may have a thickness of less than a tenth of a millimeter, for example, 0.03 mm. Alternatively or additionally, the width of the foil strip 10 may be between a few millimeters and a quarter or half a centimeter, for example, a width may be between 15 mm and 23 mm.

[0083] A spring, a spring constant, a lever arm, a length, and / or an elasticity (in particular of a shape memory material) of the movable guide surface 308 (for example, in the conveying direction) can be selected in a suitable size ratio to the extensibility of the film strip 10 in order to achieve the dynamic length compensation with a predetermined maximum deviation (for example, a maximum displacement and / or maximum elongation of the film strip 10). The deviation can, for example, be in the range between several micrometers and one millimeter, in particular 0.1 mm.

[0084] Fig. 8 shows a further embodiment of a device 300 with an embossing die 304-1 according to Fig. 7 . The embodiment of the Fig. 8 comprises a guide surface 308 designed as a straight lever arm. As in Fig. 8The lever arm length can be 4.15 mm. The foil strip 10 can be deflected at a deflection point 806 between the movable guide surface 308 and the embossing point 305 in the guide channel 306. In the example of Fig. 8 A free path length of the film strip 10 in the first position (reference symbol 402) can be 8.66 mm. Alternatively or additionally, a deflection of the film strip 10 from a flat guide channel in the first position 402 of the guide surface 308 can total 4.15 mm + 8.66 mm = 12.81 mm.

[0085] A path length of the film strip 10 in the second position 602 of the guide surface 308 can be approximately 12.01 mm from the rotation axis (e.g., a hinge) 310 to the deflection point 802. Alternatively or additionally, the change in the path length of the film strip 10 in the guide channel 306 from the first position 402 to the second position 602 can be, for example, 0.80 mm.

[0086] Fig. 9shows a further embodiment of a device 300 with a deformable (for example, shape memory) material, in particular a spring, as a movable guide surface 308. The lower half 906-1 of the device in the embodiment shown, for example, faces the embossing die and comprises the side 306-1 of the guide channel. The upper half 906-2 of the device in the embodiment shown, for example, faces the embossing pad and comprises the side 306-2 of the guide channel. Alternatively or additionally, the upper half of the device can face the embossing die and comprise the side 306-1 of the guide channel. The lower half of the device can face the embossing pad and comprise the side 306-2 of the guide channel. Alternatively or additionally, the guide surface 308 in a first embodiment, e.g., as in Fig. 9shown, on the lower half of the device 300 and in a second embodiment on the upper half of the device 300.

[0087] Although the invention has been described with reference to exemplary embodiments, it will be apparent to those skilled in the art that various changes may be made and equivalents may be substituted. Furthermore, many modifications may be made to adapt a particular situation or material to the teachings of the invention. Accordingly, the invention is not limited to the disclosed embodiments, but includes all embodiments falling within the scope of the appended claims. List of reference symbols

[0088] Foil tape 10 printing roller 12 Embossing point 14 Embossing stamp 14-1 Embossing pad 14-2 Conventional rigid guide channel 16 Side of the rigid guide channel facing the die 16-1 Side of the rigid guide channel facing the embossing pad 16-2 device 300 Roller for slip-free transport of a film strip, e.g. printing roller 302 Embossing point 304 Embossing stamp 304-1 Embossing pad 304-2 Embossing sword 304-3 guide channel 306 Side of the guide channel facing the die 306-1 Side of the guide channel facing the embossing pad 306-2 Guide surface 308 hinge 310 Preload 312 First position 402 Stop position 404 Second position 602 Holding force of the roller 604 Tensile force of the embossing point 606 Penetration depth of the stamping die 702 Width of the die at the penetration depth 704 Feed length of the foil strip during embossing 706 Angle of the wedge-shaped end (embossing blade) 708 Stop point of the guide surface 802 Free path length of the foil strip 804 Deflection point of the foil tape 806 Side of the device facing the stamping die 906-1 Side of the device facing the embossing pad 906-2

Claims

1. Device (300) for dynamic length compensation during embossing of a foil strip (10), comprising: an embossing point (304), a roller (302) which is designed for the slip-free transport of the foil strip (10), and a guide channel (306) arranged between the embossing point (304) and the roller (302), characterized in that the guide channel (306) comprises a guide surface (308) which is movable between a first position (402) and a second position (602), wherein a path length of the foil strip (10) between the roller (302) and the embossing point (304) in the first position (402) of the guide surface (308) is greater than a path length of the foil strip (10) between the roller (302) and the embossing point (304) in the second position (602), wherein the foil strip (10) is conveyed in the guide channel (306) from the roller (302) to the embossing point (304) in the first position (402) of the guide surface (308), and wherein the guide surface (308) is moved from the first position (402) into the second position (602) while the foil strip (10) is embossed.

2. Device (300) according to Claim 1, wherein the roller (302) formed for the slip-free transport of the foil strip (10) comprises a pressure roller and / or a transport roller.

3. Device (300) according to Claim 1 or 2, wherein the guide surface (308) is preloaded (312) for the movement from the first position (402) and into the second position (602).

4. Device (300) according to one of Claims 1 to 3, wherein the foil strip (10) bears, in the first position (402) and / or in the second position (602), against at least one portion of the guide surface (308) for the curvilinear guidance of the foil strip (10) in the guide channel (306).

5. Device (300) according to one of Claims 1 to 4, wherein the guide surface (308) has a rotatably mounted roller, over which the foil strip (10) is guided, preferably in a slip-free manner.

6. Device (300) according to one of Claims 1 to 5, wherein the guide surface (308) is convex on a side facing the foil strip (10).

7. Device (300) according to Claim 6, wherein a radius of curvature of the convex guide surface (308) is smaller than the path length of the foil strip (10) guided in the guide channel (306).

8. Device (300) according to either of Claims 6 or 7, wherein a radius of curvature of the convex guide surface (308) is many times greater than a thickness of the foil strip (10).

9. Device (300) according to one of Claims 6 to 8, wherein a radius of curvature of the convex guide surface (308) in the first position (402) and / or in the second position (602) is greater than a width of the guide channel (306).

10. Device (300) according to one of Claims 1 to 9, wherein the foil strip (10) bears, both in the first position (402) and in the second position (602), against the guide surface (308).

11. Device according to one of Claims 1 to 10, wherein the guide surface (308) is pivotally movable between the first position (402) and the second position (602), optionally wherein a rotational axis of the pivoting movement is arranged perpendicularly with respect to the foil strip (10) and / or perpendicularly with respect to the course of the foil strip (10) determined by the guide channel (306).

12. Device (300) according to one of Claims 1 to 11, wherein the embossing point (304) comprises an embossing punch (304-1) which is movable transversely with respect to the guide channel (306) and an embossing pad (304-2) arranged in the transverse movement of the embossing punch (304-1), and wherein the guide channel (306) opens at the embossing point (304) between the embossing punch (304-1) and the embossing pad (304-2).

13. Device (300) according to Claim 10, wherein the transverse movement of the embossing punch (304-1) into the embossing pad (304-2) shortens the path length of the foil strip (10) in the guide channel (306), optionally counter to a preload (312) of the guide surface (308).

14. Device (300) according to Claim 12 or 13, wherein the guide surface (308) and the embossing punch (304-1) move during the embossing operation in parallel with regard to a transverse direction of the guide channel (306).

15. Device (300) according to one of Claims 12 to 14, wherein the embossing punch (304-1) comprises an embossing blade (304-3) which is preferably perpendicular with respect to the guide channel (306).

16. Method for dynamic length compensation during embossing of a foil strip (10), comprising: conveying the foil strip (10) in a guide channel (306) arranged between a roller (302), which is designed for slip-free transport of the foil strip (10), and an embossing point (304), wherein the foil strip (10) is conveyed in a direction from the roller (302) to the embossing point (304), characterized in that the guide channel (306) comprises a guide surface (308) which is movable between a first position (402) and a second position (602), and wherein the guide surface (308) comprises the first position (402) when conveying, embossing the foil strip (10) by means of the embossing point (304), wherein the guide surface (308) is moved into the second position (602) during embossing, wherein a path length of the film strip (10) between the roller (302) and the embossing point (304) in the first position (402) of the guide surface (308) is greater than a path length of the foil strip (10) between the roller (302) and the embossing point (304) in the second position (602).