WINDOW REGULATOR FOR A MOTOR VEHICLE

Description

[0001] The invention relates to a window lifter for a motor vehicle, comprising a plastic component and a metal component, wherein the plastic component is in mechanical contact with a metal component at least in sections on a contact surface. The invention further relates to a door module with such a window lifter and to the use of microcapsules in a plastic granulate.

[0002] Today, movable vehicle windows are typically moved between a closed and an open position by electrically or electromotor-operated actuating devices known as (vehicle) window lifters. Such a window lifter typically comprises an (electric) actuator and an actuating mechanism that connects the actuator to the window pane, i.e., couples the force transmission. To install the window lifter in a vehicle door, it is possible to pre-assemble the window plate onto a carrier plate, also called a door module carrier or assembly carrier. The assembly comprising the window lifter and door module carrier (and, if applicable, other functional elements of the vehicle door) is also referred to below as the door module.

[0003] The adjustment mechanism of such a window lifter, for example, comprises a cable pull mechanism, which is guided on the one hand in a cable drum that winds and unwinds the cable, and on the other hand, with multiple deflections by means of (cable) deflection pulleys, is guided to a driver or rail slider and fixed there. To guide the window pane, the window pane of a vehicle door, for example, is provided with at least one rail slider as a pane guide element on a front and / or rear side window edge. This rail slider is guided in at least one guide rail of the adjustment mechanism, which acts as an adjustment or guide track, and can be moved along the vehicle height (Z direction).

[0004] Rail gliders of the aforementioned type typically comprise a plastic base body with a guide area that, when assembled, encompasses the guide rail. In other words, the guide rail sits within the guide area. The base body and the guide rail are thus engaged with each other. The base body is mounted so that it can be moved along the guide rail, so that the window pane is guided linearly between the closed and open positions.

[0005] The actuating mechanism of such window regulators thus comprises a multitude of components that move relative to one another. These components are designed, for example, as plastic parts to reduce costs and weight. High frictional forces are a frequent cause of damage to moving plastic parts. To extend the service life of such plastic parts, friction reduction and wear protection are therefore desirable. For this purpose, the contact surfaces between the moving components are regularly coated with a lubricant or anti-friction agent.

[0006] Lubricants are divided into dry lubricants and liquid or pasty lubricants. Dry lubricants or solid lubricants, such as powder coatings made of graphite or ceramic, allow for comparatively easy incorporation into plastics, but dry lubricants offer only a limited range of materials. Therefore, liquid, viscous, or pasty lubricants, such as lubricating oils or greases, are often used, which offer a wider range of materials and improved distribution or wetting properties. Furthermore, the microcapsules enable the special use of highly effective greases, such as silicone.

[0007] For example, the rail glider or its base body is designed as an injection-molded part, with the guide rail being a metal rail, for example, made of aluminum. The guide rail is, for example, powder-coated or galvanized. To improve the sliding properties, a sliding insert made of polyamide (PA) or polyoxymethylene (POM) is often inserted into the rail wraparound of the rail glider. A translational or sliding interface is formed between the rail glider and the guide rail, with a lubricating grease (for example, FK 3) usually also inserted between the powder coating (powder coating) and the sliding insert.

[0008] Another example is a pulley made of POM, which is mounted on the door module via a metal bolt for rotation. The rotating interface between the bolt and pulley is often coated with grease.

[0009] The disadvantage of lubricating greases or oils is that they require external dosing and have a comparatively high consumption. Furthermore, the effort required to apply liquid lubricants is greater than with dry lubricants. Furthermore, incorrect or neglected application of liquid or pasty lubricants can lead to damage or destruction of the components involved, thereby adversely reducing the quality of the window regulator.

[0010] US 2014 / 157677 A1 discloses a window regulator for a motor vehicle in which a matrix coating is applied to a metal blank. The matrix coating consists of particles of a fluoropolymer (such as polytetrafluoroethylene) contained in an organic polymer binder. The coated metal blank is cold-formed into the shape of a guide rail with a longitudinal track arranged along one edge of the guide rail. A window slider is mounted on the guide rail and slides along the longitudinal track, so that the fluoropolymer particles lubricate the sliding of the window slider along the longitudinal track.

[0011] The invention is based on the object of providing a particularly suitable window regulator for a motor vehicle. In particular, the aim is to ensure the most cost-effective and reliable lubrication of the adjusting mechanism possible. The invention is further based on the object of providing a particularly suitable door module and a particularly suitable application.

[0012] With regard to the window regulator, the problem is solved according to the invention with the features of claim 1, with regard to the door module with the features of claim 13, and with regard to the use with the features of claim 14. Advantageous embodiments and refinements are the subject of the dependent claims. The advantages and embodiments cited with regard to the window regulator are also transferable mutatis mutandis to the door module and / or the use, and vice versa.

[0013] The window lifter according to the invention is intended for, and is suitable and configured for, a motor vehicle. The window lifter comprises an electric actuator and a coupled actuator mechanism.

[0014] The actuating mechanism comprises a plastic component and a metal component, which are movable relative to each other and between which a mechanical interface is formed. The plastic component is designed, for example, as an injection-molded part. The plastic component has a contact surface as a mechanical or friction-stressed interface with the metal component, at which the plastic component and the metal component are in mechanical contact, at least in sections.

[0015] According to the invention, microcapsules (microbubbles) filled with a lubricant are embedded in the plastic material of the contact surface, at least in the area of the contact surface. The microcapsules are introduced, for example, into the surface of the contact surface material or close to the surface. A lubricant is understood here to mean, in particular, a pasty or liquid lubricant. In other words, a liquid or pasty lubricant, such as a lubricating grease or lubricating oil, is immobilized by means of microencapsulation and integrated into the contact surface of the plastic component. This creates a particularly suitable window lifter.

[0016] The lubrication concept according to the invention enables local, on-demand lubrication of the components to reduce friction and protect against wear, thereby improving the performance of the plastic components in particular. In particular, the lubricant microcapsules enable permanent friction minimization of the plastic components. This subsequently has a beneficial effect on the service life of the window regulator, reducing maintenance and repair work.

[0017] The lubricant microcapsules enable savings in the use of dry lubricants, such as powder coating. Furthermore, microencapsulation can be integrated into an automated system for manufacturing the plastic component with reduced effort. Furthermore, microencapsulation enables a quality improvement of the window regulator, as the lubricant cannot be misapplied or forgotten. In particular, CO2 emissions are reduced during production due to the elimination of lubricant. Furthermore, leaching is minimized or completely eliminated.

[0018] The microencapsulation of the lubricant is carried out in particular in the form of a core-shell encapsulation, in which the lubricant (core material) is enclosed in a shell material, particularly a plastic material. The microcapsules have a diameter of, for example, a few millimeters to approximately 1 µm (micrometer). Depending on the core material and shell material, the microcapsule diameter is, for example, between 5 µm and 100 µm.

[0019] The microencapsulation is designed in such a way that it opens under sufficiently high mechanical stress, releasing the enclosed lubricant. "Opening" of the microcapsules refers in particular to a rupture of the shell material, which generally releases the lubricant completely within a short time (burst). The stress level considered sufficient is initially irrelevant. In particular, the stress at which the microcapsules open can be determined by a suitable choice of encapsulation material or by varying the capsule diameter (volume of the core material) and / or the capsule wall thickness (capsule wall thickness, wall material thickness) of the microcapsules. This can be determined, for example, through trials and tests for the specific application of the components.

[0020] Because the microencapsulation is positioned particularly near the contact surface or mechanical interface or friction point, the lubricant is distributed locally or selectively at the mechanically stressed areas when the microcapsules are opened, ensuring reliable lubrication of the components. Microencapsulation thus advantageously allows lubricant to be released only when needed and in low concentrations.

[0021] Microencapsulation allows the liquid or pasty lubricant to be incorporated into the plastic component as a finely dispersed solid (powder). This effectively combines the advantages of liquid and dry lubricants. In particular, the microcapsules enable comparatively easy incorporation into the plastic material, while simultaneously utilizing the greater material versatility and improved distribution or wetting properties of the pasty or liquid lubricant.

[0022] The inventive use of microencapsulated lubricant at the interface enables lubrication even in otherwise difficult-to-access parts and components. Furthermore, the microencapsulation integrated directly into the plastic component eliminates the need for lubricants, especially dry lubricants or powder coatings, on the metal component.

[0023] In a suitable embodiment, the plastic material of the plastic component is a polypropylene (PP), a polyoxymethylene (POM), or a polyamide (PA), in particular polyamide-6 (PA 6).

[0024] In a practical embodiment, the proportion of microcapsules in the plastic material of the contact surface is between 1 wt.% (percent by weight) and 20 wt.%. In other words, the lubricant content in the contact surface is, for example, 1 wt.%, 5 wt.%, or 20 wt.%. The proportion can be flexibly adjusted to the respective lubrication requirements between the plastic component and the metal component, ensuring sufficient and reliable lubrication of the components or the interface at all times.

[0025] In one conceivable embodiment, the microcapsules, in particular the shell material, are made from the plastic material of the plastic component or the contact surface. This ensures reliable mixing of the plastic material of the contact surface and the microencapsulated lubricant. For example, the plastic material in this case is PA.

[0026] The lubrication concept according to the invention can be flexibly applied to various interfaces with plastic components or parts. For example, the microencapsulated lubricant can be used on (plastic) gears. Furthermore, the lubricant microcapsules can be used on interfaces where standard lubricating greases cause problems due to sticking.

[0027] The lubricant microcapsules are particularly advantageous for sliding interfaces, allowing, for example, the need for powder coatings on (guide) rails to be eliminated. In one advantageous application, the plastic component is designed as a sliding insert for a rail wraparound of a rail glider, with the corresponding metal component being a guide rail for the linear guidance of the rail glider, which is partially encompassed or enclosed by the rail wraparound. The sliding insert is preferably made of PA or POM.

[0028] In an equally advantageous application, the plastic component is a (cable) pulley, for example, made of POM, while the metal component is a bolt supporting the pulley. The bolt is attached, for example, to a door module carrier in the area of the guide rail. This ensures appropriate lubrication for the rotating pulley.

[0029] In a further advantageous application, the plastic component is designed as a cable drum, wherein the metal component is a cable that can be wound up and unwound thereon, for example a steel cable.

[0030] In one possible embodiment, the microcapsules are not merely localized in the contact surface or boundary layer, but are distributed throughout the entire plastic component. In other words, the microcapsules are embedded in the entire plastic material of the plastic component. Preferably, the microcapsules are distributed as homogeneously as possible, or evenly, throughout the plastic material. This means that the plastic material essentially has a constant density of microcapsules throughout the component volume. As a result, the plastic component or plastic material exhibits uniform strength or mechanical stability.

[0031] To produce such a plastic material with evenly or homogeneously distributed microcapsules, it is possible according to the invention, for example, to use plastic granules with embedded microcapsules. By incorporating the microcapsules into the granules, it is ensured that the microcapsules are particularly evenly distributed in the finished plastic component. In particular, this means that the microcapsules are already evenly distributed during the production of the plastic material, i.e. in an extruder screw or in a plastic melt. By using plastic granules with integrated microcapsules, it is thus possible to use existing injection molding systems to produce the plastic component without conversion or retrofitting. This enables particularly simple and cost-effective production of the window regulator.Advantageously, the shell of the microencapsulation, i.e. in particular the wall or wall thickness of the microcapsules, is dimensioned such that the microcapsules do not open during the production of the plastic component, i.e. in the melt or in the extruder.

[0032] An additional or further aspect of the invention provides for microcapsules with different capsule properties to be embedded in the plastic material. A capsule property is understood here, in particular, to be a geometric property of the (capsule) shell, i.e., a (shell) shape and / or a (shell) diameter and / or a (shell) wall thickness. The conjunction "and / or" is to be understood here and below in such a way that the features linked by this conjunction can be formed both together and as alternatives to one another. The different capsule properties effectively create different pressure levels at which the microcapsules open and thus release the lubricant. This allows a simple relubrication solution to be implemented.

[0033] Preferably, an activator is provided during assembly of the window lifter, which activator processes the contact surface during assembly and thereby opens at least a portion of the microcapsules, so that an initial or initial lubrication for the window lifter is realized.

[0034] In one conceivable embodiment, the activator is implemented as an activation tool, for example, a cutting or grinding tool, in particular sandpaper. Additionally or alternatively, a geometric activator in the form of a counter-contour of the metal component is conceivable.

[0035] The counter contour can, for example, be designed like a stamp, so that when the plastic component moves toward the metal component, increasing contact pressure is generated, which opens the microcapsules in the contact surface and thus lubricates the bearing point. Alternatively, the counter contour can be designed, for example, as a sharp-edged contour or burr, at which the contact surface is specifically machined during installation or assembly.

[0036] Preferably, the counter-contour is designed as a local change in the surface quality, in particular the surface roughness, of the metal component. In particular, the metal component has an increased surface roughness in the area of the counter-contour. The area of the counter-contour is thus rougher or more uneven than the rest of the metal component.

[0037] For a metal component designed as a guide rail, the counter contour is located, for example, in the area of an upper and / or lower end stop for the plastic component designed as a sliding insert. When the plastic component is moved to the end stop, the contact surface is machined by the counter contour, so that a greater local mechanical stress acts on the contact surface, causing the microcapsules to open and release the lubricant. This enables the sliding insert to be mounted between the end stops with as little friction as possible.

[0038] The door module according to the invention is intended for a motor vehicle, in particular for a side door of the motor vehicle, and is suitable and configured therefor. The door module comprises a door module carrier and a window lifter, as described above, arranged thereon. This creates a particularly suitable door module.

[0039] Exemplary embodiments of the invention are explained in more detail below with reference to a drawing. In the drawings: Fig. 1 shows a schematic and simplified representation of a door module with a window lifter, Fig. 2 shows a schematic and simplified representation of an interface between a plastic component and a metal component, Fig. 3 shows a perspective sectional view of a detail of the door module with a cable pulley and with a bolt, and Fig. 4 shows a perspective sectional view of a rail glider and a guide rail.

[0040] Corresponding parts and sizes are always provided with the same reference symbols in all figures.

[0041] In the Fig. 1 A simplified and schematic representation of a door module 2 of a motor vehicle is shown. The door module 2 is installed in a side door of the motor vehicle (not shown in detail). The door module 2 has a support plate as a door module support 4, on which an electric (vehicle) window lifter 6 is shown as an adjusting device for a (vehicle) window pane 8 of a motor vehicle.

[0042] The (vehicle) window lifter 6 has a servomotor 10, which acts on the window pane 8 by means of an adjusting mechanism 12 and a rail slider 14. In the illustrated embodiment, the window lifter 6 is designed as a single-strand lifter or single-strand cable-operated window lifter, wherein the adjusting mechanism 12 has a cable 16 and a guide rail 18 for the rail slider 14.

[0043] The actuator motor 10 of the window lifter 6 drives a cable drum 22 of the actuating mechanism 12 via a worm or spur gear 20. A pull cable of the cable pull 16 is arranged on the cable drum 22 in such a way that the pull cable is wound and unwound upon rotation of the cable drum 22 caused by the gear 20. The cable pull 16, designed, for example, as a Bowden cable, moves the rail slider 14, and thus the window pane 8, via deflection pulleys 24 of the guide rail 18.

[0044] When the actuator 10 is actuated, the window pane 8 is moved into its (pane) position P. The window pane 4 is reversibly movable between a closed position S, which represents the highest possible position P, and an open position O, which represents the lowest possible position P. In these positions S and O, the window pane 4 is in the Fig. 1 are indicated by dashed lines. Window pane 8, however, is shown in a half-open intermediate position by solid lines.

[0045] The components or parts of the adjusting mechanism 12 are designed as plastic components or metal components. Especially for plastic components that are directly connected to metal components, a lubrication concept according to the invention is integrated to reduce friction and wear, which is described below with reference to the Fig. 2 is explained in more detail.

[0046] The Fig. 2 shows a section of a plastic component 26 and a metal component 28 in the area of a mechanical or frictionally stressed interface. The frictionally stressed area of the plastic component 26 is referred to below as the contact surface 30, wherein the metal component 28 has, at least in sections, a mechanical contact with the contact surface 30 during a relative movement to the plastic component.

[0047] As in the Fig. 2 As can be seen, in the region of the contact surface, microcapsules 32 are embedded in the plastic material of the contact surface 30, each of which is filled with a lubricant, in particular a lubricating grease or a lubricating oil. Preferably, the microcapsules 32 are embedded evenly or homogeneously distributed throughout the entire plastic material of the plastic component 26. The microcapsules 32 have, for example, a shell material which is made of the same plastic as the contact surface 30. The microcapsules 32 are in the Fig. 2 provided with reference numerals merely by way of example. The proportion of microcapsules 32 in the plastic material of the contact surface 30 is, for example, between 1% and 20% by weight. The microcapsules 32 are preferably already embedded in a plastic granulate of the plastic material, so that a homogeneous distribution of the microcapsules 32 is ensured during the production of the plastic component 26.

[0048] The microcapsules 32 are designed in such a way that they open under sufficiently high mechanical stress and release the lubricant 34 enclosed therein. The microcapsules 32 can have different capsule properties, in particular different sizes, shapes, wall thicknesses, etc., so that the microcapsules 32 open under different mechanical stresses. Under mechanical stress, the plastic component 26 and the metal component 28 move relative to each other, which in the Fig. 2 indicated by a double arrow. The resulting frictional forces cause the microcapsules 32 on the surface of the contact surface 32 to open, thereby releasing the enclosed lubricant 34, which subsequently spreads over the surfaces of the plastic component 26 and the metal component 28 due to the mutual movement and wets them. As a result, when the microcapsules 32 open, the lubricant 34 is released locally or selectively at the mechanically stressed points of the contact surface 30, thus ensuring reliable lubrication of the components 26, 28.

[0049] The lubrication concept explained above is applicable to a variety of different plastic and metal components 26, 28 in the actuating mechanism 12. The following are based on the Fig. 3 and the Fig. 4 Two possible application examples are explained in more detail.

[0050] The Fig. 3 shows a cable deflection area of the window lifter 6. The deflection of the cable 16 is achieved by means of the deflection pulleys 24, which are arranged in the front end areas of the guide rail 18. The deflection pulleys 24 are mounted on bearing points and are rotatably or rotatably mounted there. The bearing point is designed, for example, as a (bearing) bolt 36, which is held on the door module carrier 4. The bolt 36 essentially forms the axis of rotation of the deflection pulley 24.

[0051] In the embodiment of the Fig. 3 The deflection pulley 24 is designed as a POM injection-molded part, with the bolt 36 being made of a metal.

[0052] In this embodiment, the deflection roller 24 thus forms the plastic component 26, and the bolt 36 forms the metal component 28.

[0053] The deflection pulley 24 has a first contact surface 30a with the carrier plate 4 and a second contact surface 30b with the bolt 36. The lubricant-filled microcapsules 32 are inserted into the contact surfaces 30a, 30b. This ensures reliable lubrication of the carrier plate / deflection pulley and the deflection pulley / bolt interfaces during rotation of the deflection pulley 24.

[0054] The lubricant microcapsules 34 are particularly advantageous for sliding interfaces. Such a sliding interface is realized, for example, between the rail slider 14 and the guide rail 18. The application of the lubrication concept is in Fig. 4 shown.

[0055] The guide rail 18 has, for example, an L-shaped contour in cross-section. The rail slider 14 has a molded rail wrap 38 for this L-contour of the guide rail 18. A clip-in or clipped-in sliding insert 40 is releasably attached to the rail wrap 38, which slide insert 40 rests against the guide rail 14 with four contact surfaces 30a, 30b, 30c, 30d as punctiform running surfaces. The sliding insert 40 is designed as a plastic part with particularly good sliding properties, i.e., with the lowest possible frictional resistance with respect to the guide on the guide rail 14.

[0056] The rail slider 14 is made, for example, of a mechanically stable plastic material, so that the actuating forces acting on the actuating mechanism 12 during operation are guided safely and reliably. The rail slider 14 is made, for example, of a polyamide (PA), in particular of a glass-fiber-reinforced polyamide (PA-GF), for example with a glass fiber content of approximately 35%. The sliding insert 56 is designed, for example, as a POM injection-molded part, with the guide rail 18 being made of a metal.

[0057] In this embodiment, the sliding insert 56 forms the plastic component 26, and the guide rail 18 forms the metal component 28. The microcapsules 32 are integrated into each of the four contact surfaces 30a, 30b, 30c, 30d. The contact surfaces 30a, 30b and 30c, 30d are arranged in pairs opposite one another. The contact surfaces 30a, 30b bear opposite one another on the vertical L-shaped leg of the guide rail 18, while the contact surfaces 30c, 30d bear opposite one another on the horizontal L-shaped leg of the guide rail 18.

[0058] For example, it is possible to provide an activator, i.e. an activation tool or a counter-contour of the metal component 28, which processes the plastic component 26 or the contact surface 30 during assembly and / or during operation of the window lifter 6 and thus opens the microcapsules 32. In an application according to Fig. 4For example, in the area of an upper and / or lower end stop of the guide rail 18, a counter contour in the form of a local surface roughening is provided, so that the microcapsules 32 are opened in particular in the area of the counter contour or the end stop.

[0059] Although exemplary embodiments and applications have been explained in the preceding description, it should be noted that numerous modifications are possible without departing from the scope of the claims. In particular, such a lubrication concept according to the invention is also suitable for the cable drum 22 as a plastic component and the traction cable as a metal component. Furthermore, it should be noted that the exemplary embodiments are merely examples and are not intended to limit the scope of protection, applications, or design in any way.Rather, the foregoing description provides the person skilled in the art with a guide for the implementation of at least one exemplary embodiment, wherein various changes, in particular with regard to the application to the components of the actuating mechanism 12, can be made without departing from the scope of protection as it results from the claims and their equivalent combinations of features. List of reference symbols

[0060] 2 Door module 4 Door module carrier 6 Window lifter 8 Window pane 10 Actuator 12 Adjusting mechanism 14 Rail slider 16 Cable pull 18 Guide rail 20 Worm / spur gear 22 Cable drum 24 Deflection pulley 26 Plastic component 28 Metal component 30, 30a, 30b, 30c, 30d Contact surface 32 Microcapsule 34 Lubricant 36 Bolt 38 Rail wrap 40 Sliding insert PSlice position Sclosed position Oopen position

Claims

1. Window lifter (6) for a motor vehicle, comprising a plastics component (26) and a metal component (28), wherein the plastics component (26) is at least partially in mechanical touching contact with the metal component (28) on a contact surface (30, 30a, 30b, 30c, 30d), characterized in that microcapsules (32) filled with a lubricant (34) are embedded in the plastics material of the plastics component (26) at least in the region of the contact surface (30, 30a, 30b, 30c, 30d).

2. Window lifter (6) according to Claim 1, characterized in that the plastics material is polypropylene, polyoxymethylene, or polyamide-6.

3. Window lifter (6) according to Claim 1 or 2, characterized in that the proportion of microcapsules (32) in the plastics material of the contact surface (30, 30a, 30b, 30c, 30d) is between 1 weight per cent and 20 weight per cent.

4. Window lifter (6) according to one of Claims 1 to 3, characterized in that the microcapsules (32) are made of the plastics material.

5. Window lifter (6) according to one of Claims 1 to 4, characterized in that the plastics component (26) is a sliding insert (40) of a rail wraparound means (38) of a rail slider (14), and in that the metal component (28) is a guide rail (14), around which the rail wraparound means (38) at least partially engages.

6. Window lifter (6) according to one of Claims 1 to 4, characterized in that the plastics component (26) is a deflection roller (24), and in that the metal component (28) is a bolt (36) which mounts the deflection roller (24).

7. Window lifter (6) according to one of Claims 1 to 4, characterized in that the plastics component (26) is a cable drum (22), and in that the metal component (28) is a cable that can be wound up thereon.

8. Window lifter (6) according to one of Claims 1 to 7, characterized in that the microcapsules (32) are distributed throughout the plastics material of the plastics component (26).

9. Window lifter (6) according to Claim 8, characterized in that the microcapsules (32) are as far as possible homogeneously distributed in the plastics material.

10. Window lifter (6) according to one of Claims 1 to 9, characterized in that microcapsules (32) with different shapes and / or diameters and / or wall thicknesses are embedded in the plastics material.

11. Window lifter (6) according to one of Claims 1 to 10, characterized in that the contact surface (30, 30a, 30b, 30c, 30d) is worked by an activation tool in the course of mounting in such a way that at least some of the microcapsules (32) are made to open and release lubricant (34) on the contact surface (30, 30a, 30b, 30c, 30d).

12. Window lifter (6) according to one of Claims 1 to 11, characterized in that the metal component (28) has a mating contour for selective release of the lubricant (34).

13. Door module (2) for a motor vehicle, comprising a door module carrier (4) and a window lifter (6) according to one of Claims 1 to 12 arranged thereon.

14. Use of microcapsules in a granulated plastic for producing a plastics component (26) for a window lifter (6) according to one of Claims 1 to 12.