DEVICE AND USE OF THE DEVICE FOR STRIPPING A CABLE

Description

[0001] The invention relates to a device for stripping a cable with an outer protective sheath, wherein the device comprises a support roller arrangement and a working wheel arrangement, wherein the support roller arrangement is arranged on a rotating base of the device which is rotatable about an axis of rotation and the working wheel arrangement is arranged on a working wheel guide, wherein the rotating base and the working wheel guide are connected to each other via at least one guide and the working wheel guide is displaceable relative to the rotating base in a guide direction extending transversely to the axis of rotation, wherein the support roller arrangement comprises at least two support rollers which are rotatably mounted on the rotating base about a support roller axis and the working wheel arrangement comprises a rolling wheel which is rotatably mounted on the working wheel guide about a rolling wheel axis and wherein a clamping area is formed around the axis of rotation and between the at least two support rollers and the rolling wheel.the diameter of the working wheel guide can be increased or decreased depending on the direction of movement by shifting it in the guide direction relative to the base of rotation. The invention also relates to the use of this device for stripping a cable with an outer protective sheath, which is to be removed by stripping the insulation.

[0002] Shielded cables essentially consist of a shielded conductor assembly comprising one or more conductors, at least one shielding layer surrounding the conductor assembly, and an outer protective sheath. The shielding layer and the protective sheath are arranged concentrically around the conductor assembly, with the shielding layer protecting the conductor assembly against electric or magnetic fields and the protective sheath arranged around the shielding layer providing, in particular, mechanical protection against external influences and electrical insulation of the conductor assembly.

[0003] The shielding layer of a shielded cable often consists of a braided shield and a foil shield surrounding the braid. The protective jacket, in turn, surrounds the foil shield. An additional problem when stripping the insulation is the friction between the protective jacket and the foil shield. Sometimes the protective jacket and foil shield are even glued or welded together. With such cables, stripping must be done in a single step, as the protective jacket cannot be removed on its own. In these situations, stripping is particularly tricky because part of the shielding layer has to be removed without damaging the braided shielding layer.

[0004] To connect shielded cables, it is necessary to cut the protective jacket around the entire length of the cable at a certain distance from the cable end and then peel it off the shielding layer, possibly along with a shielding foil. This process is also known as stripping. However, the shielding layer, or at least the necessary portion of it, must remain intact; otherwise, after connecting the cable, effective shielding cannot be guaranteed, or connecting the shielding, usually to an electrical reference potential, will not be possible at all.

[0005] The shielding layer generally consists of an extremely thin and delicate material, such as thin aluminum foil, a metallic-coated plastic film (shielding film), a fine wire mesh, or several such layers. The protective sheath, on the other hand, must be made of a robust material, such as durable plastics like PUR, PVC, silicone, etc., and must have a corresponding thickness. The protective sheath is significantly thicker than the shielding layer.

[0006] Stripping shielded cables is therefore usually done manually and requires dexterity and experience. Even well-known mechanical tools, such as wire strippers or rotary cutters, require very careful and experienced handling, as the shielding can easily be damaged with them as well. For example, DE 21 58 888 A1 describes a wire stripper with which the cable is manually cut lengthwise. To move the stripper along the cable, a wheel with radially projecting points is used, which press superficially into the cable sheath. FR 2 373 131 A also shows a stripping process along the cable, where a wheel with projecting points is also used to move the cable towards a cutting blade. In both cases, the wheels with the radially projecting points have nothing to do with the stripping process itself, i.e., with cutting the cable sheath.

[0007] Especially the assembly of numerous shielded cable connections, as is required in the industrial production of electric cars, can therefore be a time-consuming undertaking.

[0008] EP 2 693 581 A1 discloses a device for stripping shielded cables with a blade arrangement rotatable around the cable, the position of which is adjustable for making a cut in the protective sheath. An electronic detection device detects when the blades come into contact with the shielding; however, it is usually too late when the detection device is triggered, as the shield or conductor has already been cut or damaged.

[0009] WO 2019 / 243193 A1 discloses a device for stripping a shielded cable, comprising a support roller assembly with multiple support wheels and a working wheel assembly with a roller wheel. During use, the cable is clamped between the support roller assembly and the working wheel assembly, and both assemblies rotate around the stationary cable. The working wheel assembly is displaceable transversely to the axis of rotation, allowing the roller wheel to penetrate the outer protective sheath of the cable and cut it along its circumference. The working wheel assembly may also include a cutting wheel or blade to assist in cutting the protective sheath. A disadvantage of this device is that the roller wheel can deform or even damage the sensitive shielding layer, or a portion thereof, when used with softer cables.This was particularly noticeable with cables whose shielding layer is surrounded by a shielding foil that also has to be cut during stripping. Cutting such a shielding foil requires considerable pressure from the cutting wheel, which can deform or damage the underlying parts of the shielding layer, such as a braided shield.

[0010] The object of the present invention is to provide devices and methods with which the stripping of cables, in particular shielded cables, can be carried out simply and safely without adversely affecting a shielding layer through stripping, in particular through deformation or damage.

[0011] This problem is solved according to the invention by a device of the type mentioned at the outset, in which a plurality of perforation elements are arranged around the circumference of a radially outer rolling contour on the rolling wheel, projecting radially from the rolling contour by a certain length. The rolling wheel effectively cuts through the protective sheath, which is usually made of a plastic, by rolling along the cable sheath along a cutting area, thus wearing down the material of the cable sheath until the cable sheath can no longer withstand the pressure of the rolling wheel, allowing it to penetrate radially into the cable sheath and cut through it. However, the rolling wheel cannot penetrate a harder and more rigid shielding layer within the cable, and this layer therefore remains undamaged.On the other hand, the radially projecting perforation elements ensure that the local pressure of the roller on the shielding layer, particularly on the braided shielding of a shielding layer, remains low, thus preventing any adverse deformation or even damage to the shielding layer. Furthermore, the perforation elements also perforate any existing shielding foil, which can then be easily removed from the cable along the perforation. The perforation elements penetrate the underlying braiding only slightly, so that it is not damaged. The required pressure of the roller can be easily generated and controlled by suitable actuators, such as springs or appropriate actuators.

[0012] Advantageously, the length and / or position of the guide can also be adjusted, for example by means of limiting elements and / or adjusting screws. This allows the device to be easily adapted to different cable thicknesses.

[0013] To assist in cutting through the cable's protective sheath, the working wheel assembly additionally includes a cutting wheel rotatably mounted on the working wheel guide about a cutting wheel axis, with a radially outward-facing cutting edge, or a cutting edge arranged on the working wheel guide. In this case, the clamping area is formed between the at least two support rollers, the roller wheel, and the cutting wheel. The cutting wheel actively cuts into the protective sheath, thus facilitating the radial penetration of the roller wheel into the protective sheath.

[0014] It is advantageous if the radially outer rolling contour of the roller wheel is positioned closer to the axis of rotation than the radially outer edge of the cutting edge of the cutter wheel. This ensures that the cutting edge of the cutter wheel does not come into contact with the shielding layer, particularly with a braided shielding layer, during the stripping process and thus avoid damaging it.

[0015] To ensure that the perforation elements reliably perforate a shielding foil but do not penetrate too far into the shielding mesh of a shielding layer, it is preferably provided that the length of the perforation elements is between 0.02mm and 0.5mm.

[0016] In order to be able to use the rolling wheel for different cables and to achieve the most uniform perforation patterns possible along the circumference, it is advantageously provided that two circumferentially adjacent perforation elements are spaced apart from each other circumferentially by a perforation increment, wherein the perforation increment is located in a region U n U n + 1 The perforation increment is defined as follows: where n is a natural number between 2 and 15, preferably between 2 and 10, and U is a circumferential length on a radius around the axis of rotation at which the perforation elements are to create perforations when the device is used. The perforation increment is preferably selected as centrally as possible within this area.

[0017] If the working wheel guide has an eccentric weight distribution relative to the axis of rotation, causing a centrifugal force to act on the working wheel guide when the rotating base, with the working wheel guide mounted on it via the guides, rotates around the axis of rotation, the required contact force to cut through the protective sleeve can be easily generated by the centrifugal force. This can be easily and reliably influenced and controlled by the weight distribution and / or the rotational speed. In this case, no actuating devices, such as tension springs or actuators, are required to generate the contact force.

[0018] The device is used for stripping a cable with an outer protective sheath, wherein the end of the cable to be stripped is clamped in the clamping area between the roller of the working wheel assembly and the at least two support rollers of the support roller assembly by applying a pressure force, wherein the unit of working wheel assembly and support roller assembly rotates around the cable by rotating the rotation base and the roller and the at least two support rollers roll along the cable and the working wheel guide with the working wheel assembly is moved in the guide direction in the direction towards the axis of rotation, so that the roller penetrates radially into the protective sheath of the cable in a cutting area generated by the rolling contour and thereby cuts through the protective sheath of the cable along the circumference.The displacement of the working wheel guide with the working wheel arrangement is advantageously effected by the pressure force, which is preferably caused by an acting centrifugal force.

[0019] During stripping, it is preferably provided that the roller penetrates radially into the cable's protective sheath until the roller contour reaches a shielding layer within the cable. If the shielding layer comprises a braided shield and a surrounding shielding foil, the roller preferably penetrates radially into the cable until the roller contour reaches the shielding foil within the cable, thereby perforating the foil around its circumference with the roller's perforation elements. In this way, stripping and perforation of the shielding foil can be achieved simultaneously, allowing the foil to be easily peeled off along the perforation along with the detached protective sheath.

[0020] To easily monitor the stripping process, the shield braid of the cable being stripped can be electrically contacted using an electrical test contact. This test contact is electrically connected to the stripping roller, and a measuring device and continuity test are used to check whether the roller makes contact with the shield braid during stripping. If contact is detected, the stripping process is stopped. For example, a required electrical voltage can be applied between the test contact and the stripping roller to perform the continuity test.

[0021] To ensure the quality of the stripping process, it can also be provided that the shield braid of the cable being stripped is electrically contacted using an electrical test contact. This test contact is then electrically connected to the cutting wheel or blade, and a measuring device and an electrical continuity test are used to check whether the cutting wheel or blade comes into contact with the shield braid during stripping. In this way, cables where the cutting wheel or blade came into contact with the shield braid during stripping can be rejected.

[0022] The present invention is described below with reference to the Figures 1 to 13 In more detail, the invention is explained, and exemplary, schematic, and non-restrictive embodiments are shown. This includes showing Fig. 1An exemplary embodiment of the device according to the invention for stripping cables, shown schematically in a front view, Fig. 2 the in Fig. 1 Device shown in a sectional view along line II-II in Fig. 1 , Fig. 3 a cable shown schematically in cross-section, which is arranged in the device according to the invention for stripping and the working wheel and support roller arrangement acting on the cable, Fig. 4 a typical cross-section of a cable to be stripped, with a braided shield and a shielding foil, Figs. 5 to 8 various designs of a rolling wheel with perforation elements, Fig. 9 an irregular perforation pattern, Fig. 10 a regular perforation pattern, Fig. 11 an electrical continuity test for quality assurance of the stripping process, Fig. 12 a device with a roller wheel as a working wheel arrangement and Fig. 13a device with a roller wheel and a cutting edge as a working wheel arrangement.

[0023] The in Figs. 1 and 2 An exemplary device for stripping a cable 4 has a rotating base 2, preferably plate-shaped, which is rotatable about an axis of rotation 1. A support roller arrangement 20, consisting of a plurality of support rollers 3, for example a pair of support rollers 3 as in the illustrated embodiment, is arranged on the front of the base 2. Each support roller 3 is rotatably mounted on the rotating base 2 about a support roller axis 3'. When the device is in use, the rotating base 2 rotates about the axis of rotation 1. For this purpose, the rotating base 2 is driven to rotate about the axis of rotation 1 in a predetermined direction.

[0024] The rotation base 2 can, for example, be connected via a shaft 19 to a drive (not shown), such as a motor or a combination of a motor and a gearbox, which drives the rotation base 2.

[0025] The support roller axes 3' of the support rollers 3 are preferably arranged parallel to the axis of rotation 1 of the base of rotation 2 and have a radial distance A (e.g. Fig. 3The rotation of the cable 4 is oriented towards the axis of rotation 1, which is selected with respect to the diameter of the cable 4 to be stripped such that the cable 4, arranged on the support rollers 3, is centered on the axis of rotation 1, i.e., the longitudinal axis of the cable 4 coincides with the axis of rotation 1. The diameters of the support rollers 3 and their radial distances A do not necessarily have to be the same. If necessary, the radial distance A of the support rollers 3 on the rotation base 2 can be adjusted to accommodate cables 4 of different diameters. Alternatively, the rotation base 2 can be changed to adapt to different cables 4. During the stripping of the cable 4, the position of the support rollers 3 relative to the rotating rotation base 2 remains unchanged, with the support rollers 3 moving around the cable 4 with the rotating rotation base 2 and rolling onto its outer sheath.

[0026] A working gear guide 5, preferably plate-shaped, is arranged on the base of rotation 2 and is displaceable relative to the base of rotation 2 in a guide direction 6 extending transversely, preferably perpendicularly, to the axis of rotation 1. The working gear guide 5 can, for example, be connected to the base of rotation 2 via one or more guides 7. A guide 7 can be designed as a linear guide, as shown in Figs. 1 and 2A linear guide can be designed as a slotted guide, in which sliding elements are slidably arranged in guide slots. However, guides 7 of any other design can also be used. If necessary, the length of the guides 7 can also be adjusted and / or limited, for example, by means of adjustable limiting elements (such as adjusting screws), in order to restrict the possible range of motion of the working wheel guide 5 relative to the base of rotation 2. Suitable guides 7 and corresponding limiting elements are well known to those skilled in the art and therefore do not need to be described in more detail here. Sufficient precision of movement must be ensured when designing the guides 7.

[0027] The rotation base 2 may optionally be provided with a central recess 21 into which the end of the cable 4 can protrude or through which the cable 4 can protrude, thus minimizing the space required by the rotating parts. The recess 21 is in Fig. 1 It is only shown schematically; however, it can also be significantly deeper and can even extend through the entire base of rotation 2. In the latter case, the drive mechanism for the base of rotation 2 must be designed appropriately.

[0028] A working wheel assembly 10 is arranged on the working wheel guide 5, wherein the working wheel assembly 10 comprises at least one rolling wheel 8. In an advantageous embodiment, the working wheel assembly 10 additionally comprises a cutting wheel 9. In a preferred embodiment, the working wheel assembly 10 comprises a rolling wheel 8 and a cutting wheel 9. Such an embodiment is described in Figs. 1 and 2 depicted.

[0029] This design of the device creates a clamping area 24 around the axis of rotation 1 and between the at least two support rollers 3 and the roller wheel 8, and optionally the cutting wheel 9. This clamping area can be enlarged or reduced by moving the working wheel guide 5 in the guide direction 6 relative to the base of rotation 2, depending on the direction of movement. The cable 4 to be stripped is arranged in this clamping area 24 and, when the device is in use, clamped between the at least two support rollers 3 and the roller wheel 8, and optionally the cutting wheel 9. As the base of rotation 2 rotates, the support roller assembly 20 with the support rollers 3 and the working wheel guide 5 with the roller wheel 8, and optionally the cutting wheel 9, rotate around the clamping area 24. If a cable 4 is arranged and clamped in the clamping area 24, the support rollers 3 and the roller wheel 8, and optionally the cutting wheel 9, roll along the outer sheath of the cable 4.Cable 4 does not rotate.

[0030] The roller wheel 8 and cutter wheel 9 (if present) are rotatably mounted on the working wheel guide 5 and, for this purpose, have a roller wheel axis 8' and cutter wheel axis 9' preferably arranged parallel to the axis of rotation 1. With respect to the axis of rotation 1 (and the position of the cable 4 defined above it in the device), the working wheel assembly 10 is arranged in the guide direction 6 on the side opposite the support rollers 3, so that the cable 4 resting on the support rollers 3 can be clamped between the support rollers 3 and the working wheel assembly 10 by sliding the working wheel assembly 10 in the guide direction 6. In the embodiment according to Fig. 1The cable 4 is clamped between the support rollers 3 and the roller wheel 8 and the cutter wheel 9 of the working wheel assembly 10. When the rotation base 2 rotates about the rotation axis 1, the support rollers 3, the roller wheel 8 and the cutter wheel 9 (if present) roll along the sheath of the cable 4, i.e., its protective sheath 14, in a circumferential direction along a cutting area 15.

[0031] It should be noted that the cutting area 15 need not be a cutting line, but generally designates an area extending in the axial direction of the cable 4 in which the protective sheath 14 of the cable is to be cut. As will be explained further below, the effect of the roller 8 on the cable 4 also extends laterally in the axial direction beyond the area of ​​direct contact between the roller 8 and the protective sheath 14, so that the roller 8 and the cutting wheel 9 can also be arranged slightly offset from each other laterally in the axial direction (as in Fig. 2(shown). The axial area affected by the action of the roller wheel 8 is referred to as the cutting area 15 in connection with the present invention.

[0032] The cable 4 can also be secured in a fixed (i.e., not rotating with the rotating parts of the device) clamping device 22, which is located in Fig. 2 The clamping device 22 can be arranged very close to the working wheel guide 5 and press the cable 4 into its round cross-sectional shape and hold it in place during machining. This is particularly advantageous for softer cables 4. If necessary, the free end of the cable 4 can also be held with a corresponding internal clamping device 22' (this is shown in Fig. 2(also shown schematically), wherein the inner clamping device 22' can, for example, be mounted on the rotation base 2 by means of a ball bearing (not shown). Thus, the inner clamping device can remain stationary during the rotation of the moving parts and center the cable 4. The inner clamping device 22' can then also be used, for example, to pull the separated part of the protective sheath 44 off the cable 4 after processing.

[0033] At the end of the work wheel guide 5 opposite the working wheel arrangement 10 with respect to the axis of rotation 1 in the guide direction 6, in the embodiment according to Figs. 1 and 2 A weight 16 is provided which gives the working wheel guide 5 an eccentric weight distribution with respect to the axis of rotation 1. The eccentric weight distribution can also be ensured without an additional weight 16 solely by the shape of the working wheel guide 5.

[0034] When the rotation base 2, with the working wheel guide 5 arranged on it via the linear guides 7, rotates about the axis of rotation 1, a centrifugal force Fzf acts on the working wheel guide 5 in the guide direction 6 due to the eccentric weight distribution. This causes the working wheel guide 5, with the working wheel assembly 10, to be pressed against the outer surface of the cable 4 (or against the counterforce applied by the support rollers 3). The contact force of the working assembly 10 against the cable 4 can thus be controlled structurally by the design of the weight distribution of the working wheel guide 5, for example by means of a weight 16, and procedurally by the rotational speed. If necessary, the weight 16 can be designed to be interchangeable or adjustable in order to vary the contact force.The working wheel guide 5 can optionally be pre-tensioned into the "open" position, in which the support rollers 3 and the working wheel assembly 10 are furthest apart, by means of clamping devices such as springs. In this position, the working wheel assembly 10 only comes into contact with the protective sheath 14 of the cable 4 when the rotation base 2 of the device rotates sufficiently fast and the working wheel guide 5 is sufficiently counteracted by the centrifugal force Fzf by the force applied by the clamping device. Alternatively or additionally, the drive of the rotating parts can be controlled such that the weight 16 is positioned at the top when the device is at rest, so that the working wheel assembly 10 is automatically pressed downwards (i.e., into the open position) by its own weight.

[0035] The contact force can also be applied by suitable actuating means, such as a spring or a stall drive. In this case, an eccentric weight distribution of the working wheel guide 5 is also not required. A combination of an actuating drive and the effect of a centrifugal force Fzf is also conceivable.

[0036] In the context of the present disclosure, the term "front" refers to the side of the device on which the cable 4 to be stripped is to be arranged, i.e., the side in Fig. 1 displayed page or in Fig. 2the right side. This term is used solely for understanding and orientation and is not to be interpreted restrictively. In particular, it would also be possible to "reverse" the arrangement of the rotation base 2 and the working wheel guide 5, so that the working wheel guide 5 with the elements attached to it is located opposite the front, i.e., "behind" the rotation base 2, with the cable 4 then being inserted through a central opening provided in the rotation base 2 to come into contact with the working wheel assembly 10 and the support roller assembly 20. Optionally, the working wheel assembly 10 can also be arranged axially between the rotation base 2 and the working wheel guide 5, or it can be protected within an interior space of the working wheel guide 5. The implementation of the design modifications required for such alternative embodiments is within the capabilities of a person skilled in the art.

[0037] Cable 4 consists, as in Fig. 4The cable 4 is shown to consist essentially of one or more conductors 11 arranged in a conductor assembly 12 that forms the core of the cable 4. The individual conductors 11 can be electrically insulated from each other or from the outside, and depending on the cable type, further layers may be provided, for example, to separate individual conductor bundles within the conductor assembly 12. A shielding layer 13 is provided around the conductor assembly 12, for example, a thin metal foil, such as one made of aluminum or copper, or a delicate braided shield 25 made of metal wire. The shielding layer 13 may optionally consist of several such layers. Such shielding layers 13 are well known in the field in a wide variety of embodiments and therefore do not need to be described in more detail here.Since the shielding layer 13 is usually made of relatively expensive material(s), manufacturers strive to make this layer as thin as possible. Therefore, the shielding layer 13 is usually very sensitive, especially to mechanical stress. The outermost layer of the cable 4, the protective sheath 14, is arranged around the shielding layer 13. This sheath protects the unit consisting of the conductor assembly 12 and the shielding layer 13 from external influences and serves as electrical insulation for the cable 4.

[0038] The shielding layer 13 can also comprise a shielding foil 26 surrounding a shielding braid 25 or a metal foil (or both). The shielding foil 26 is typically made of plastic, usually as a metal-coated plastic foil (either by vapor deposition of a metal layer onto the plastic foil or by laminating a metal foil with a plastic foil).

[0039] To strip the cable 4, the protective sheath 14 must be removed along an axial section of the cable 4, typically in the area of ​​the axial free end of the cable 4. If the shielding layer 13 also includes a shielding foil 26, then the shielding foil 26 must also be removed to expose the braided shield 25 or the metal foil (or both) in this area for electrical contact. The braided shield 25 or the metal foil (or both) should not be excessively deformed or damaged in the process.

[0040] The rolling wheel 8 and the cutting wheel 9 each have a different cross-section in a plane parallel to their axis of rotation 8', 9', as shown in Fig. 3The hatching indicates the specific features. In particular, the cutting wheel 9 forms a radially circumferential, radially outer cutting edge 17, while the rolling wheel 8 has a blunter edge geometry radially outward than the cutting wheel 9, which, in connection with the present disclosure, is referred to as the rolling contour 18. The rolling contour 18 of the rolling wheel 8 is designed to suit the material parameters of the protective jackets 14 to be cut and the set or adjustable contact forces such that the rolling wheel 8 does not cut into the material of the protective jacket 14, but merely presses and slightly displaces the material. In contrast, in connection with the present invention, a "cutting edge" is considered to be a contour that, under these conditions, cuts into the material of the protective jacket 14.The cutting wheel 9 therefore tapers to a point at the radial end towards the cutting edge 17, while the rolling wheel 8 has an axial width at its radial end as a rolling contour 18 which is adapted to the material parameters of the protective jacket 14.

[0041] The continuous stress on the protective sheath 14 caused by the rolling contour 18 of the roller wheel 8 rotating around the cable 4 impinges on the material of the protective sheath 14 in the cutting area 15, causing it to become brittle. This causes the roller wheel 8 to penetrate the protective sheath 14 radially by displacing the material. If a cutting wheel 9 is also provided, the protective sheath 14 can be easily cut by the cutting wheel 9 due to this rolling action, which facilitates stripping. However, the protective sheath 14 can also be cut by the roller wheel 8 alone.

[0042] Since the shielding layer 13 is made of a different material (i.e., metal) than the protective jacket 14 (i.e., plastic), the pressure of the rolling contour 18 on the shielding layer 13 causes only a smaller deformation than on the material of the protective jacket 14. Therefore, as soon as the rolling contour 18 enters the area of ​​the shielding layer 13, the rolling wheel 8 is indented less deeply. Ideally, the further movement of the working wheel guide 5 with the rolling wheel 8 in the guide direction 6 is stopped when the rolling contour 18 reaches the shielding layer 13. This can be achieved by appropriately designing the rotational speed of the rotation base 2 and / or the eccentric weight distribution of the working wheel guide 5.

[0043] If the working wheel assembly 10 includes a cutting wheel 9, then it is advantageous if the cutting wheel 9, which moves along with the rolling wheel 8 as part of the working wheel assembly 10, does not come into contact with the shielding layer 13. The shielding layer 13 therefore cannot be cut by the cutting wheel 8 and thus damaged.

[0044] For this purpose, it can be provided that the outer radial edge of the rolling contour 18 is arranged slightly closer to the axis of rotation 1 than the outer radial edge of the cutting edge 17. This is in Fig. 3The difference between the (larger) distance D between the cutting edge 17 and the axis of rotation 1 and the (smaller) distance d between the rolling contour 18 and the axis of rotation 1 is very small and can be, for example, between 5% and 50%, preferably between 10% and 20% of the layer thickness of the protective coating 14 to be cut. For example, the difference (Dd) can be between approximately 50 µm and 200 µm, in particular approximately 100 µm.

[0045] The difference (Dd) can be produced constructively in various ways. In a very simple embodiment, for example, the rolling wheel 8 and the cutting wheel 9 can each have different outer radii, wherein the outer radius R of the rolling wheel 8 is larger than the outer radius r of the cutting wheel 9, as shown in Fig. 3This is shown. This makes it possible to arrange the axes of rotation 8', 9' of the rolling wheel 8 and the cutting wheel 9 at the same radial distance from the axis of rotation 1, which is structurally advantageous. In another possible embodiment, the axes of rotation 8', 9' of the rolling wheel 8 and the cutting wheel 9 can lie on different diameters. In this case, the outer radii r, R can also be the same.

[0046] Possible radii, distances, and contours are shown in Fig. 3The cable 4, arranged coaxially on the axis of rotation 1, is held in position between the two support rollers 3 and the working wheel assembly 10, consisting of a roller wheel 8 and a cutting wheel 9, which presses against the support rollers 3 due to the acting contact force, for example, due to the centrifugal force Fzf. The rollers and wheels rotate around the cable 4 due to the rotation of the base 2. In this process, the roller wheel 8 rolls and displaces the material of the protective sheath 14, thus very quickly leading to controlled material fatigue, so that the material at this point can be cut by the "following" cutting wheel 9. The roller wheel 8 then penetrates radially into this cut and displaces and further fatigues the material.

[0047] Once the roller wheel 8 reaches the material of the shielding layer 13, further displacement and penetration into the material are prevented due to the higher strength of the shielding layer 13 and the conductor arrangement 12. The roller wheel 8 then rolls on the surface of the shielding layer 13 without penetrating further into the cable 4, thus preventing the shielding layer 13 from coming into contact with the cutter wheel 9. This layer is in Fig. 3 The dashed outline of roller wheel 8 and cutter wheel 9 is shown. It is greatly exaggerated that the cutter wheel 9 does not touch the shielding layer 13. The drive of the device can then be switched off, the cable 4 removed, and the detached part of the protective sheath 14 pulled off.

[0048] The design of the rolling contour 18, in particular the axial width and the geometry at the radial end of the rolling wheel 8, is either known or can be easily carried out by appropriate tests with cables 4 to be stripped.

[0049] Particularly in the case of cables 4 with a shielding foil 26 in the shielding layer 13, a high contact force of the rolling wheel 8 on the cable 4 may be necessary to cut the shielding foil 26. For example, the rolling wheel 8 would have to penetrate the cable 4 sufficiently until the shielding foil 26 is cut by a cutting wheel 9. However, this could result in significant deformation or even damage to the other parts of the shielding layer 13, especially a shielding braid 25, which must be avoided. To remedy this, perforation elements 27 are provided on the rolling contour 18 of the rolling wheel 8, distributed around its circumference. These perforation elements project a predetermined radial length L from the radially outer rolling contour 18 of the rolling wheel 8. This is demonstrated by advantageous embodiments in the Fig. 5-8 depicted.

[0050] In Figs. 5 and 6Figure 8 shows an embodiment of a rolling wheel 8 with perforation elements 27, wherein the perforation elements 27 are an integral part of the rolling wheel 8, i.e., formed in one piece with the rolling wheel 8. For this purpose, the rolling wheel 8 can, for example, be injection-molded from plastic (such as PEEK (polyetheretherketone) or a filled or fiber-reinforced plastic) and then machined, in particular to ensure the desired length L. However, the rolling wheel 8 can also be made of metal (steel or stainless steel), and the perforation elements 27 can be machined using a subtractive manufacturing process. Other known manufacturing processes for producing the perforation elements 27, such as wire EDM or spark erosion, are also conceivable.

[0051] In the execution according to Figs. 7 and 8The rolling wheel 8 is made of plastic (such as PEEK (polyetheretherketone) or a filled or fiber-reinforced plastic) or metal (steel or stainless steel), with needles inserted into the rolling contour 18 as perforation elements 27. The needles are made, for example, of steel or stainless steel. The needles can have a diameter of 0.1 mm to 0.5 mm. To achieve a precise length L of the perforation elements 27, the inserted needles can be ground to the desired length L after insertion.

[0052] The shape of the protruding perforation elements 27 can be tapered to a point, for example conical or pyramidal, but can also be prism-shaped or cylindrical.

[0053] The length L by which the perforation elements 27 project radially from the rolled contour 18 is preferably between 0.02 mm and 0.5 mm. This ensures that the perforation elements 27 perforate a shielding foil 26, typically with a thickness of 10 to 100 µm, without damaging other underlying parts of the shielding layer 13, in particular a shielding braid 25. Furthermore, no large radial contact forces are required for perforation, which significantly reduces or completely prevents the risk of unwanted deformation and damage to a shielding braid 25 or other parts of the shielding layer 13. If no shielding foil 26 is present, the perforation tips 27 penetrate a shielding braid 25 without causing any significant or adverse deformation.

[0054] A roller 8 with perforation elements 27 allows the protective sheath 14 to be easily and reliably cut through as described above. When the roller 8 reaches the shielding layer 13, any shielding foil 26 present is perforated around the entire circumference of the cable 4 with just a few revolutions of the roller 8. The severed protective sheath 14, along with the shielding foil 26, can then be easily removed, with the shielding foil 26 tearing cleanly at the perforation. In this way, stripping can be achieved with lower pressure forces and less penetration depth of the roller contour 18 into the cable 4, thus preventing deformation of sensitive parts of the shielding layer 13, such as a braided shield 25.

[0055] The circumferential spacing between two adjacent perforation elements 27 on the roller 8 (perforation increment P) is preferably selected such that, during repeated rotations of the cable 4 during stripping, the perforations in the shielding foil 26 do not create excessively large gaps between perforations 30 or excessively closely spaced perforations 30 (clusters of perforations). Both can lead to an unclean separation of the shielding foil 26, which can result in fraying and a ragged cut. This can impair the quality of the stripped cable 4 and its further use.

[0056] In Fig. 9For example, an accumulation of perforations 30 produced by the perforation elements 27 on a screen film 26 (which is shown here unwound for illustration) can occur. A cluster 31 of perforations 30 and larger gaps 32 between perforations 30 can be seen distributed along the circumference U of the screen film 26. The perforations 30 are in Fig. 9 For better understanding, different geometric figures are used, each corresponding to a circumnavigation of the cable 4 by the rolling wheel 8. These accumulations 31 and gaps 32 arise from an unfavorably chosen perforation increment P on the rolling wheel 8. The perforation increment P is understood to be the arc length between two adjacent perforation elements 27 on the rolling wheel 8.

[0057] To avoid such accumulations 31 or gaps 32, the perforation increment P in the area U n U n + 1 The value of n is chosen, where n is a natural number. Here, U denotes the circumferential length on the radius around the axis of rotation 1 in the region of the cable 4 on which the perforations 30 are to be produced. This is usually the radius on which the shielding foil 26, which is to be perforated, lies. Advantageously, n is chosen such that, with the expected number of revolutions of the cable 4 by the roller 8 for perforation, the distance between adjacent perforations 30 in the circumferential direction does not become less than 1 to 3 mm, because an excessively small perforation increment P can also lead to an unclean separation. For typical cables 4, the natural number n lies between 2 and 15, preferably between 2 and 10.If the perforation increment P is chosen approximately in the middle of this area, a continuous application range of the rolling wheel 8 for different cable diameters within a specific diameter range is achieved, whereby accumulations 31 and / or gaps 32 can be avoided.

[0058] A desired perforation pattern with perforations 30 on a screen film 26 without such accumulations 31 and / or gaps 32 is in Fig. 10 shown for comparison.

[0059] However, different rolling wheels 8 can of course be used for different cables 4, or for different cable diameter ranges, whereby the perforation increment P of the perforation elements 27 of the rolling wheel 8 is adapted to the respective cable 4.

[0060] An electrical continuity test can also be used to monitor the quality of the stripping process, as demonstrated by: Fig. 11 is explained. Fig. 11Only cable 4 is shown, but not the other parts of the device, for example as in Figs. 1 and 2As shown, for continuity testing, a braided shield 25 of the cable 4 is electrically contacted by means of a test contact 40. The test contact 40 can be designed as an electrically conductive blade or brush and contacts the braided shield 25 in the region of the axial end of the cable 4. Alternatively, the test contact 40 can be designed as a plate that is axially spaced from the cable end and positioned in the region of the braided shield 25. The resulting air gap between the plate and the braided shield 25 can be bridged by supplying ionized air, thus establishing a sufficient electrical connection between the plate and the braided shield 25. The test contact 40 is electrically connected to the cutting wheel 9 via a test lead 41. The cutting wheel 9 must be electrically conductive for this purpose.An electrical connection between the test contact 40 and the cutter wheel 9 can then be detected using a measuring device 42, for example by applying a test voltage and measuring a current. If an electrical connection is detected, the cutter wheel 9 would have inadvertently touched the braided shield 25, which is detected in this way, thus preventing further use of the cable.

[0061] A second test contact of 45 (in Fig. 11(dashed line) is provided, which, as described above, is also intended to contact the shield braid 25. This second test contact 45 is connected to the first test contact 40 via a second test line 44. This allows an electrical continuity test to be performed between the first test contact 40 and the second test contact 45 using a second measuring device 43 to ensure that the first test contact 40 is making contact with the shield braid 25. The test procedure can be carried out as follows: first, using the first and second test contacts 40 and 45 and a continuity test, it is determined whether the first test contact 40 is making electrical contact with the shield braid 25; and then, using the first test contact 40, it is verified whether the cutter wheel 9 is touching the shield braid 25.

[0062] Such a continuity test can also detect when the roller 8 reaches the braided shield 25 or the shielding foil 26. If the roller 8 is electrically conductive, it can be determined, as described above, by means of a test contact on the braided shield 25, which is electrically connected to the roller 8, that the perforation elements 27 of the roller 8 penetrate the braided shield 25. If this is detected, the stripping process of the cable 4 can be stopped. If a shielding foil 26 is also present in the cable 4, this simultaneously ensures that the shielding foil 26 has been perforated as desired by the perforation elements 27.

[0063] Due to its simple and stable construction, the device according to the invention can be operated at high speeds, for example between 100 rpm and 5000 rpm. The process of stripping a cable 4 can therefore be carried out very quickly, requiring only a few seconds for a stripping operation. It is also unnecessary to measure the cutting of the protective sheath 14 with complex and error-prone devices, since cutting the desired parts of the shielding layer 13 is impossible with the device according to the invention anyway.

[0064] In Fig. 3For clarity, the roller wheel 8 and the cutter wheel 9 are shown relatively far apart. However, to securely clamp the cable 4 between the working wheel assembly 10 and the support rollers 3, it is preferable to arrange the roller wheel 8 and the cutter wheel 9 close together, whereby the circumferential contours of the two wheels may overlap, provided the wheel profiles allow this. Wheel profiles for roller wheel 8 and cutter wheel 9 that allow overlapping are shown, for example, in Fig. 2 This arrangement utilizes the property of the roller wheel 8, which deforms and wears down the material of the protective sheath 14 not only in direct contact, but also in a certain area laterally to this contact.

[0065] In the design according to Fig. 12The working wheel arrangement 10 comprises only one roller 8 with perforation elements 27, which rolls along the cable 4, pressing against the protective sheath 14 and thereby fatigues the sheath material until it can no longer offer sufficient resistance to the penetration of the roller 8. The roller 8 thus penetrates further and further into the material of the protective sheath 14 until it reaches the shielding layer 13 and the perforation elements 27 perforate a shielding foil 26 (if present).

[0066] Fig. 13 shows another alternative design of the working wheel arrangement 10. Fig. 13 This shows that the working wheel arrangement 10 can not only use wheels, but can also include other, non-rolling elements. In particular, in Fig. 13A rolling wheel 8 with perforation elements 27 is shown, combined with an "off-center" arranged cutting edge 23. The arrangement of the cutting edge 23 is chosen such that, when the device functions correctly, it cannot come into contact with parts of the shielding layer 13 that must not be damaged. In use of the device, the cutting edge 23 is fixed (but possibly adjustable) on the working wheel guide 5. The cutting edge 23 is arranged such that, when the working wheel guide 5 moves in the guide direction 6, the cutting edge 23 cannot touch the shielding layer 13, or any part thereof. This is easily achieved due to the known geometry of the cable 4. The cutting edge 23 assists the rolling wheel 8 in cutting through the protective sheath 14.

Claims

1. A device for stripping a cable (4) having an outer protective sheath (14), the device having a support roller arrangement (20) and a work wheel arrangement (10), the support roller arrangement (20) being arranged on a rotation base (2) rotatable about an axis of rotation (1) and the work wheel arrangement (10) being arranged on a work wheel guide (5), the rotation base (2) and the work wheel guide (5) being connected to one another via at least one guide (7) and the work wheel guide (5) being displaceable relative to the rotation base (2) in a guide direction (6) running transversely to the axis of rotation (1), wherein the support roller arrangement (20) comprises at least two support rollers (3) each mounted on the rotation base (2) so as to be rotatable about a support roller axis (3') and the work wheel arrangement (10) comprises a rolling wheel (8) mounted on the work wheel guide (5) so as to be rotatable about a rolling wheel axis (8') and wherein a clamping region (24) is formed around the axis of rotation (1) and between the at least two support rollers (3) and the rolling wheel (8), which clamping region can, by displacing the work wheel guide (5) in the guide direction (6) relative to the rotation base (2), be enlarged and reduced depending on the displacement direction, characterized in that a plurality of perforation elements (27) are arranged on the rolling wheel (8) on a radially outer rolling contour (18) such that they are distributed over the circumference, which perforation elements protrude radially by a length (L) from the rolling contour (18).

2. The device according to claim 1, characterized in that the work wheel arrangement (10) additionally comprises a cutting wheel (9) mounted on the work wheel guide (5) so as to be rotatable about a cutting wheel axis (9') and having a radially outer cutting edge (17), whereas the clamping region (24) is formed between the at least two support rollers (3), the rolling wheel (8) and the cutting wheel (9).

3. The device according to claim 2, characterized in that the radially outer rolling contour (18) of the rolling wheel (8) has a blunter edge geometry than the radially outer cutting edge (17) of the cutting wheel (9).

4. The device according to claim 2 or 3, characterized in that the radially outer rolling contour (18) of the rolling wheel (8) is arranged closer to the axis of rotation (1) than the radially outer edge of the cutting edge (17) of the cutting wheel (9).

5. The device according to claim 1, characterized in that the work wheel arrangement (10) additionally comprises a cutting blade (23) arranged on the work wheel guide (5).

6. The device according to claim 2 or 5, characterized in that the rolling contour (18) defines a cutting region (15) and the cutting edge (17) of the cutting wheel (9) or the cutting blade (23) is arranged in said cutting region (15).

7. The device according to any of claims 1 to 6, characterized in that the length (L) is between 0.02 mm and 0.5 mm.

8. The device according to any of claims 1 to 7, characterized in that two perforation elements (27) adjacent in the circumferential direction are arranged spaced apart from one another in the circumferential direction by a perforation increment (P), the perforation increment (P) being in a range U n U n + 1 , n being a natural number between 2 and 15, preferably between 2 and 10, and U indicating a circumferential length on a radius about the axis of rotation (1) on which the perforation elements (27) produce perforations (30) when the device is used.

9. The device according to any of claims 1 to 8, characterized in that the work wheel guide (5) has an eccentric weight distribution in relation to the axis of rotation (1), as a result of which a centrifugal force (Fzf) acts on the work wheel guide (5) when the rotation base (2) with the work wheel guide (5) arranged on the rotation base via the guides (7) rotates about the axis of rotation (1).

10. Use of the device according to any of claims 1 to 9 for stripping a cable (4) having an outer protective sheath (14), the end of the cable (4) to be stripped being clamped in the clamping region (24) between the rolling wheel (8) of the work wheel arrangement (10) and the at least two support rollers (3) of the support roller arrangement (20) by applying a pressure force, the unit formed of the work wheel arrangement (10) and the support roller arrangement (20) rotating around the cable (4) by rotation of the rotation base (2) causing the rolling wheel (8) and the at least two support rollers (3) to roll over on the cable (4) and the work wheel arrangement (10) to displace in the guide direction (6) toward the axis of rotation (1), so that the rolling wheel (8) radially penetrates the protective sheath (14) of the cable (4) in a cutting region (15) produced by the rolling contour (18) and severs the protective sheath (14) of the cable (4) along the circumference.

11. The use according to claim 10, characterized in that, if the work wheel arrangement (10) additionally comprises a cutting wheel (9) or a cutting blade (23), the cutting wheel (9) or the cutting blade (23) additionally penetrates the protective sheath (14) of the cable (4) in the cutting region (15) of the rolling wheel (8) and supports the severing of the protective sheath (14).

12. The use according to claim 10 or 11, characterized in that the rolling wheel (8) radially penetrates the protective sheath (14) of the cable (4) until the rolling contour (18) reaches a shielding layer (13) in the cable (4).

13. The use according to claim 11, characterized in that the shielding layer (13) comprises a shielding braid (25) and a shield foil (26) surrounding the shielding braid (25), and the rolling wheel (8) radially penetrates the cable (4) until the rolling contour (18) reaches the shield foil (26) in the cable (4), as a result of which the shield foil (26) is perforated over the circumference thereof by the perforation elements (27) of the rolling wheel (8).

14. The use according to claim 13, characterized in that the shielding braid (25) of the cable (4) to be stripped is electrically contacted by means of an electrical test contact (40), and the test contact (40) is electrically connected to the rolling wheel (8), and a measuring device (42) and an electrical continuity check are used to check whether the rolling wheel (8) comes into contact with the shielding braid (25) during stripping and the stripping process is ended in the event that contact is identified.

15. The use according to claim 13, characterized in that the shielding braid (25) of the cable (4) to be stripped is electrically contacted by means of an electrical test contact (40), and the test contact (40) is electrically connected to the cutting wheel (9) or the cutting blade (23), and a measuring device (42) and an electrical continuity check are used to check whether the cutting wheel (9) or the cutting blade (23) comes into contact with the shielding braid (25) during stripping.