EP4028668A1

EP4028668A1 - Improved tolerance compensating fastening means

Info

Publication number: EP4028668A1
Application number: EP20772015.2A
Authority: EP
Inventors: Gérald BUGLI; Frédéric DEGOUTTE
Original assignee: Zephyros Inc
Current assignee: Zephyros Inc
Priority date: 2019-09-12
Filing date: 2020-09-09
Publication date: 2022-07-20
Also published as: WO2021048218A1

Abstract

The present invention relates to a tolerance compensating fastening means, to be applied in or at a structure with dimensions comprising a tolerance, the fastening means comprising a first nut with an outer thread and a second nut with an inner thread, wherein the two threads interact such that a relative rotational movement of the two nuts leads to an axial displacement of the nuts relative to each other and wherein there is a gap between the two nuts extending from the inner and outer surfaces of the nuts. The present invention further relates to the production of the tolerance compensating fastening means, assembly means and a method to fix a part at a structure, particularly the structure of a vehicle.

Description

Improved Tolerance Compensating fastening means

Tolerance compensating fastening means are known from the state in the art and within vehicle production are for example placed into the cavity of a pillar, for example a roof pillar or other cavities in the vehicle-roof and are utilized to fix a roof-rail to the vehicle. However, the tolerance compensating fastening means according to the state in the art have the deficiency that they can only be applied after the inside cavity or inside of the panel has been corrosion- protected, for example e-coated. Furthermore or alternatively, often during attachment of a part, for example a roof-rail, the vehicle-body.

It is therefore the problem of the present invention, to provide a tolerance compensating fastening means, a method to produce the tolerance compensating fastening means assembly means, a fixation set, and/or a method to fix a part at a structure, that do not have the deficiencies according to the state in the art.

The problem is attained with a tolerance compensating fastening means, to be applied in or at a structure with dimensions comprising a tolerance, the fastening means comprising a first nut with an outer thread and a second nut with an inner thread, wherein the two threads interact such that a relative rotational movement of the two nuts leads to an axial displacement of the nuts relative to each other and wherein there is a gap between the two nuts, wherein the gap and/or the thread is sealed.

The disclosure made regarding this embodiment of the present invention also applies to the other inventions and vice versa. Subject matters from this embodiment can be included in other embodiments and vice versa.

The present invention relates to a tolerance compensating fastening means which is applied in or at a structure, particularly a vehicle structure and even more particular in the cavity of such a structure. Since the structure is being produced with tolerances, the inventive fastening means must be able to compensate this tolerance. This is accomplished by first nut with an outer thread and a second nut with an opening with an inner thread. The opening of the second nut extends over the entire axial height of the second nut. The first nut also comprises a, preferably cylindrical, opening, which comprises extends over the entire axial height of the first nut, to take up a fastening means, preferably a screw. The two threads of the first- and second nut interact such that a relative rotational movement of the two nuts in one direction leads to an axial displacement of the nuts relative to each other, so that the axial height of the tolerance compensating fastening means increases until the first- and the second nut each touch two opposing sidewalls of the structure, particularly the cavity. Before the tolerance compensating fastening means is installed in/at the structure, the two nuts are threaded together, preferably to the maximum extent, resulting in a minimal axial extension of the two nuts. However, there will be always a gap between the two nuts. According to the invention, this gap is at least partially, preferably entirely, sealed, so that little or no liquid, for example a coating, can enter the gap and solidify. The gap preferably extends from the inner and/or outer surfaces of the first- and/or second nut. The gap preferably includes the interface between the threads of the first- and second nut. Preferably, the gap is sealed at the outer and/or inner circumference of the first- and/or second nut.

According to an alternative or additional embodiment, the thread between the two nuts is at least partially sealed. This sealing can be executed, by providing a substance, for example a grease, an adhesive and/or a liquid-repellent substance, into the thread between the two nuts. Preferably, the substance is liquid or semi liquid. Preferably, the substance is added prior to screwing the two nuts together. The substance at least partially covers the surface of the thread. The sealing of the thread hinders for example water and/or a coating substance from entering into the thread and/or to totally fill the thread with for example water, a watery- substance and/or a coating substance, which may solidify there. In this case, the water, a watery-substance and/or coating substance may enter the gap but not the thread.

The nuts are preferably made from metal, preferably steel.

The sealing, preferably a coating or preferably a separate part, more preferably a plastic or rubber part, or preferably by an overmould, as disclosed below, prevents that a liquid, specifically a coating and/or water, enters into the gap and solidifies there, so that the torque needed to turn the two nuts relative to each other is too high. According to another inventive or preferred embodiment of the present invention, the nuts are provided with a water- and/or color-proof-coating over the inner and outer surface of both nuts in the vicinity of the gap, respectively.

The coating covers the gap, preferably at both of its ends so that no liquid can enter the gap.

The coating can be any water- and/or coating-proof-coating, for example an overmould material is preferably a plastic material, more preferably a thermoplastic material, even more preferably a polyamid and/or a rubber material. After the coating the coating material preferably solidifies on the surface of the two nuts.

The connection between the coating, preferably the overmould and the nuts is preferably waterproof, or proof regarding a potential coating such as e-coating and/or a color-coating. The connection between the coating, preferably the overmould, at the inner opening of the two nuts and the first nut has to be such, that the coating, preferably the overmould, and the first nut corotate during the axial movement of the nuts relative to each other for the tolerance compensation.

Preferably, the first nut comprises at the circumference of the inner opening a means that can be utilized for a form-fit-connection with the coating, preferably the overmould.

Preferably, this means is a groove that extends at least partially around the inner circumference or the inner opening of the first nut. Preferably, this groove is ring shaped. The groove is at least partially filled during coating, for example overmoulding, of the two nuts.

Each coating, preferably the overmould, is preferably essentially cylindrical, but may comprise a flange and/or a circular extension.

The inner diameter of the coating, preferably the overmould, provided at the inner opening of the two nuts has preferably a diameter or a shape that a the thread of a screw rotated within the coating, preferably the overmould, cuts a thread into the coating, preferably the overmould, and/or induces a torque onto the first nut sufficiently high to rotate the first nut relative to the second nut until both nuts are in contact with the structure to which the tolerance compensating fastening means is attached. Thereafter, the screw is just advanced through the inner coating, preferably the overmould, while it is screwed into the part to fixed. The friction between the screw and the inner coating, preferably the overmould, preferably maintains the position between the two nuts.

The problem is also attained with a method to produce the inventive tolerance compensating fastening means, whereby the assembled first nut and second nut are placed into a die of an injection moulding apparatus and that the gap is overmoulded and thereby sealed.

According to this embodiment of the present invention, the first- and the second nut, are screwed together, preferably to an extent, that the gap between the nuts is minimal. Then the assembled two nuts are placed in a die of an injection moulding apparatus and the gap is coated, preferably overmould and thereby sealed. The gap is preferably coated, preferably overmould at its two ends. Preferably, an essentially cylindrical coating, preferably overmould is provided at the inner- and outer diameter of the two nuts. After the coating, preferably the overmould has at least partially solidified, the coated, preferably overmoulded nuts are removed from the die.

The problem is also attained by an assembly means to attach tolerance compensating fastening means, preferably as disclosed above, to a structure. The assembly means comprise a carrier which holds the tolerance compensating fastening means. The carrier also supports a layer of expandable material.

According to this subject matter of the present invention, an expandable material is provided to a carrier, which is placed into the structure together with tolerance compensating fastening means. The expandable material is preferably a thermo-expandable material, more preferably a thermoexpandable polymer, even more preferably a epoxy expandable foam The expandable material preferably expands under the influence of heat, more preferably during curing of a coating to which the structure has been subjected. During or after expansion the expandable material solidifies, preferably by crosslinking of the expanded foam. The expanded material is preferably a foam, more preferably a structural foam, which increases the mechanical properties of structure, particularly against buckling.

The expandable material is preferably a plastic material, preferably a polymer, more preferably an epoxy based expandable material.

Preferably, the carrier comprises an indentation, in which the tolerance compensating fastening means is fixed, preferably clamped. Preferably, the second nut is connected to the carrier and more preferably fixed torque-proof, so that is does not corotate together with the first nut.

The layer of expandable material is preferably provided sheet-like. More preferably the expandable material surrounds the circumference of the circumference of the tolerance compensating fastening means in a horizontal plane. Preferably, the sheet-like expandable material comprises a hole, through which the tolerance compensating fastening means extend. Preferably, there is a gap between the tolerance compensating fastening means and the expandable material.

The expandable material is preferably overmould onto the carrier. The expandable material preferably sticks to the carrier by adhesion.

The assembly means comprising the tolerance compensating are preferably produced by placing the assembled nuts and coated for waterproofness in a mold, preferably automatically, for example by a robot. The carrier, preferably a Nylon carrier, is injected around the nuts, preferably by maintaining a free-play. As a next or simultaneous step, expandable foam is overmolded on the carrier, preferably in the same mould. Finally, the mould is opened and the assembly means including the nuts can be removed.

The problem is also attained by a method to fix a part at a structure, the utilizing the inventive assembly, wherein

- the assembly means are fixed into a cavity of the structure,

- expanding the expandable material under the influence of heat and thereby filling the cavity at least partially and hardening of the expanded material,

- inserting and rotating a fastening means in the hole of the first nut and thereby rotating the first nut relative to the second nut until the first nut and the second nut are in contact with sidewalls of the cavity, respectively and - extending the fastening means into the part until it is fixed to the structure.

This invention relates to a method to fix a part, for example a roof-rail to the structure of the roof of a vehicle, by utilizing the inventive tolerance compensating fastening means and/or the inventive assembly means, which are preassembled and then fixed, preferably without a tool, to the structure of the vehicle. Preferably, the assembly means are clipped onto the structure. Optionally, the structure is then closed and further optionally, the structure is then coated, for example with an anti-corrosion coating. During the coating the assembly means and the tolerance compensating fastening means will be exposed to the coating. Subsequently, the expandable material is expanded under the influence of heat and thereby fills the cavity at least partially. After and during expansion, the expanded material hardens, preferably by crosslinking. During hardening and/or thereafter, a fastening means, preferably a screw is inserted into the tolerance compensating fastening means, preferably into the tube-shaped overmould at the inner circumference of the first- and second nut. The thread of the screws preferably cuts into the coating, preferably the overmould, on the nuts and thereby induces a rotation onto the first nut relative to the second nut, so that the gap between the two nuts increases until both nuts are in contact with the surface of the structure. Then the screw further advances through the coating, preferably the overmould, until it sticks out of the structure, so that it can be screwed into the part to be fixed and thereby fixes the part to the structure.

Preferably, the expanded material reinforces the cavity. Preferably the deformed material avoids a deformation of the cavity or a metal panel above the cavity when a torque is applied onto the assembly means.

In addition to the above description, the following additional features, particulars, modifications and/or variations of the general teachings are contemplated as well for each of the embodiments.

The nuts, carrier, and coating can be made of one or more materials. The one or more materials may be sufficiently strong to retain the one structure to another structure, provide reinforcement to a structure, avoid deformation, or any combination thereof. The one or more materials may include one or more metals, one or more polymeric materials, or both. Metal may include cast iron, steel, stainless steel, titanium, aluminum, plain carbon steel, the like, or any combination thereof. Polymeric material may be any material which may be molded, extruded, and/or the like. For example, the polymeric material may be injection molded. Polymeric material may include a thermoset polymer, a thermoplastic polymer, or a combination thereof. Polymeric material may include polyamide (e.g., Nylon), polyester, polypropylene, polyethylene, polycarbonate, polybutadiene, acrylonitrile butadiene styrene (ABS), or any combination thereof, such as PC/ABS. Polymeric material may be filled or unfilled. A filler (e.g., reinforcement fibers) may include glass, aramid (e.g., Kevlar®), or both. One or more of the nuts, carrier, and coating may be made from a same or a dissimilar material. Both nuts may be made of the same material to avoid galvanic corrosion. One nut may be made of different material to provide for a sacrificial anode. As an example, both nuts may be made of metal, such as steel. As another example, one nut may be made of metal while another nut is made of a polymeric material.

The expandable material may function to adhere the carrier to a surface, such as a wall of a cavity within a structure. The expandable material may function to provide a seal, sound mitigation, and/or structural reinforcement. The seal may prevent entry of debris and fluid into a cavity, opening, or both. The expandable material may function to isolate the tolerance compensator from the structure.

The expandable material may be located anywhere on the carrier. The expandable material may be located on a portion of the carrier which partially or completely surrounds a tolerance compensating fastening means. The expandable material may be free of contact with a tolerance compensating fastening means, in the pre-expanded state, expanded state, or both. The expandable material may be located on a support surface configured on the a carrier. The expandable material may be located on one or two sides of a support surface configured on the carrier. The expandable material may be located on opposing sides of a support surface of a carrier. The expandable material may be partially or completely contained within the carrier. The expandable material may partially or completely fill the body of the carrier. The expandable material may extend from one end to another end of a carrier. The expandable material may be continuous, intermittent, or both as it extends along the support surface of the carrier. The expandable material may extend conterminously with one or more flanges (e.g., side walls) of the carrier.

The expandable material may be capable of activation for expansion by an external stimulus (e.g., to at least partially fill a gap or cavity). External stimulus may include application of heat, moisture, radiation, or a combination thereof. The expandable material may be capable of curing to form an adhesive bond to at least one surface. The expandable material may be capable of expanding in a paint bake oven during an electric coating process such that the activatable material will activate, expand, and then cure. An activation temperature for a blowing agent of the activatable material may be below the activation temperature of the curing agent.

The resulting expanded material may be expanded to at least about 50%, 100%, 200%, 400%, 600%, or even 1000% of its original volume. The resulting expanded material may be expanded from its original volume, but in an amount that is below about 2500%, 2000% or even below about 1500% of its original volume. Expansion may be limited such that the resulted expanded material does not flow outside of the cavity, does not flow into the opening of the carrier, or both.

Expansion of the expandable material may be substantially perpendicular to the support surface of a carrier. Expansion of the expandable material may be substantially upward, downward, or both. Expansion of the expandable material may include some lateral expansion. Expansion of the expandable material may be from the support surface to a generally parallel surface of a structure. For example, a wall of a cavity of the structure may be substantially parallel to the support surface of the carrier.

The expandable material may be comprised of one or more materials. It is contemplated that the expandable material can be activated to form a foam. For instance, the material may be activated to form a structural foam (e.g., the material may include an epoxy ingredient). The material may be activated to form an acoustic foam, energy absorbing foam, structural foam, or a combination thereof. The material may be activated to flow for purposes of sealing a region within a cavity, such as sealing against fluid and debris. The material may include one or more expandable materials, non-expandable materials, or both. For example, the material may be a combination of an inner material that is activatable to expand and an outer material that is not activatable to expand. As another example, the material may be made entirely of one or more expandable materials.

The expandable material may be an epoxy-based material including an epoxy resin, a curing agent, and an optional filler. The expandable material may be a resinous generally dry to the touch or tacky (in which case it may include a handling layer). The expandable material may be shaped in any form of desired pattern, placement, or thickness. The expandable material may be a relatively high expansion foam having a polymeric formulation that includes one or more of an epoxy resin, an acetate (e.g. ethylene vinyl acetate), a thermoplastic polyether, an acrylate and/or a methacrylate (e.g., a copolymer of butyl acrylate and methyl acrylate), an epoxy/elastomer adduct, and one or more fillers (e.g., a clay filler, and/or a nanoparticle- containing filler). For example, and without limitation, the expandable material may also include an EVA/rubber-based material, including an ethylene copolymer or terpolymer that may possess an alpha-olefin.

As described previously, the first nut, second nut, or both may have a form-fit-connection with the coating (e.g., overmold). A form-fit-connection may mean interference fit, friction fit, or other mechanical connection, with or without an intermediate layer of bonding agent. It is possible that one of the nuts (e.g., the first nut) may be free of a form-fit-connection with the coating.

The first nut, second nut, or both may have one or more attachment features for having the coating secured thereto. The one or more attachment features may provide for additional surface area for a coating to be in contact with, provide for a form-fit-connection, or both. The one or more attachment features may be located on an inner surface, outer surface, or both of the first nut, second nut, or both. The one or more attachment features may include one or more projections, depressions, or both. One or more depressions may include one or more grooves, threads, notches, indentations, the like, or any combination thereof. One or more projections may include one or tabs, ribs, posts, the like, or any combination thereof. One or more attachment features may extend partially or completely about an inner circumference, outer circumference, or both of the first nut, second nut, or both. One or more attachment features may extend partially or completely along a length of the first nut, second nut, or both. The one or more attachment features may be continuous, intermittent, or both.

The coating may extend along one or more surfaces of the first nut, second nut, or both. The coating may extend along part or all of a length of a first nut, second nut, or both. The coating may extend partially along an outer surface, inner surface, or both of the first nut, second nut, or both. The coating may be located on one or more flanges, rims, outer surfaces, inner surfaces, curved surfaces, plane surfaces or any combination thereof of the first nut, second nut, or both.

The coating may be formed on the first nut, second nut, or both. The coating may first be formed and then assembled to the first nut, second nut, or both. The coating may be die-cut, extruded, injection molded, the like, or any combination thereof.

The coating may include one or more ribs. The one or more ribs may function to align a fastening means (e.g., screw), prevent cross-threading, provide for a friction-fit between the coating and the fastening means, still allow for movement of the fastening means within the first nut, or a combination of both. The friction fit of between the coating and the fastening means may allow for the coating, first nut, or both to move with the fastening means when being secured to another structure (e.g., roof rail). The one or more ribs may project toward the center of the opening of one or more nuts. The one or more ribs may be formed as part of an interior surface of the coating. The exposed surface of the one or more ribs may create an inner diameter of the coating. The inner diameter of the coating may be less than or equal to the outer diameter of the fastening means. The one or more ribs may include one or more, two or more, or even four or more ribs. The one or more ribs may include ten or less, eight or less, or even six or less ribs. The one or more ribs may be spaced out evenly or irregularly about the interior surface of the coating. The one or more ribs may alternatively include one or more projecting structures. The one or more projecting structures may include one or more tabs, posts, teeth, threads, the like, or any combination thereof.

The carrier may include one or more fasteners (e.g., fastening means, clipping means). The one or more fasteners may function to secure the carrier to a surface of a structure. The surface may be a wall of a cavity, panel, or the like (e.g., a vehicle roof panel). One or more fasteners may include a single fastener or a plurality of fasteners. One or more fasteners may include one or more, two or more, or even three or more fasteners. One or more fasteners may include six or less or even four or less fasteners. One or more fasteners may project from a support surface of the carrier. One or more fasteners may project opposite a roof rail (e.g., once assembled), opposite a screw, or both. The one or more fasteners may be symmetrical or asymmetrical. The one or more fasteners may be integrally formed with the carrier or separately formed from the carrier. The one or more fasteners may include a threaded fastener, an opening for receiving a fastener, a fir tree fastener, arrowhead fastener, push pin fastener, clip fastener, a hook-like fastener, a friction-fit fastener, the like, or any combination thereof.

The carrier may function to retain a tolerance compensating fastening means, affix an assembly means into a cavity or other surface, retain and/or direct flow of an expandable material, or any combination thereof. The carrier may be a one-piece structure or may be comprised of multiple pieces. The carrier may include one or more support surfaces, openings, flanges (e.g., side walls), anti-rotation features, expandable materials, the like, or any combination thereof. A support surface may function to retain one or more expandable materials. An opening may be formed in the support surface. The opening may be substantially centered or off-center. A tolerance compensating fastening means may reside within the opening. An interior wall of the of the support surface forming the opening may include one or more anti-rotation receiving features. The anti-rotation receiving features may include one or more flanges, notches, or both. The anti-rotation receiving features may allow for one or more anti-rotation means (e.g., anti-rotation structure, keyed structure) to pass through. One or more flanges may extend about at least a portion of an exterior periphery, interior periphery, or both of the carrier. One or more flanges may be continuous, discontinuous, or both about the exterior periphery, interior periphery, or both. The one or more flanges may help retain an expandable material, guide the flow and/or expansion of the expandable material, or both. The carrier may be substantially symmetrical or asymmetrical. The carrier may have mirror symmetry about both a longitudinal and lateral axis. The carrier may be configured to have rotational symmetry.

As an alternative approach to producing the assembly means, the tolerance compensating fastening means may first be assembled separate from the carrier. As a previous, subsequent, or even simultaneous step, the carrier may have the expandable material located thereon. The expandable material may be overmolded, extruded, or even die-cut and then adhered to the carrier. Thereafter, the tolerance compensating fastening means may be located through the opening of the carrier. The tolerance compensating fastening means may be inserted through a bottom. The bottom may be the side facing opposite a future secondary structure (e.g., roof rail). The tolerance compensating fastening means may be aligned during insertion such that one or more anti-rotation means are aligned with, located in, or both one or more anti-rotation features of the carrier. After insertion, the tolerance compensation means may be rotated, or otherwise located, such that it resists pull through. One or more anti-rotation means may prevent pull-through.

As has been discussed, the assembly means may be useful in affixing one or more roof rails, cross members, or both to a vehicle roof to result in a roof rack assembly. Even though the present teachings contemplate a roof rack assembly including an assembly means with a tolerance compensator, the tolerance compensator has additional applications. The assembly may also be useful in one or more other rails or other structures with a cavity of a vehicle. The assembly may be useful for affixing a spare tire to a panel of a vehicle, a bumper to a frame of a vehicle, a tool box within a truck bed, or attaching other components to a frame or panel of a vehicle, or any combination thereof. While the present teachings are focused on vehicle use, the assembly means may be useful in structural supports, walls, and/or surfaces in building construction, non-automotive transportation vehicles (e.g., aircraft, watercraft, rail or otherwise), furniture, and even appliances. Among the many benefits of the present teachings is that when the assembly means is assembled to a pillar and/or within a cavity, there may be no visible deformation of structural material of the pillar and/or cavity walls within the region. Visible deformation may mean that a vehicle A-surface may be free of evidence of deformation occasioned by the assembly.

Free of evidence of deformation may mean there is no visible deformation of the surface in excess of 1 mm from normal tolerance to a person of 20/20 vision from a distance of three feet.

The assembly means may be beneficial so a roof-rail may be maintained in a fixed position and withstand manufacturing specifications for roof rack assemblies.

The structure may be formed by extrusion, welding, stamping, rolling, the like, or a combination thereof. The structure may be formed such that a cavity is formed therein. For example, a roof-rail may be extruded (e.g., an extruded aluminum rail). As another example, a rail may be welded stainless steel rail.

The inventions are now being explained according to Figures 1 to 7. The explanations apply to all inventions likewise. The explanations do not limit the scope of protection.

Figure 1 to Figure 1b show the inventive tolerance compensating fastening means.

Figure 2 shows the manufacturing of the inventive tolerance compensating fastening means.

Figure 3 shows the inventive assembly means.

Figure 4 shows the steps of fastening a part to a structure.

Figure 5 shows details of the inventive tolerance compensating fastening means.

Figures 6 and 7 show alternatives to seal the thread

Figure 1 shows the inventive tolerance compensating fastening means 11, which comprises a first nut 1 and second nut 2. The first nut 1 comprises at its outer circumference a thread 9, which cooperates with the thread 9 at the inner circumference of the second nut 2. The two nuts have an opening 23, preferably a cylindrical opening, along their center axis, through which a fastening means (not depicted) can be inserted. Between the two nuts 1 ,2 there is gap 3, which extends in the present case from the outer circumference and/or the inner circumference of nuts 1 ,2 and which is in contact with the thread 9. In the present case, nut 1 comprises a rim/flange 6 and the second nut 2 comprises a support flange 8. The gap 3 here extends between the rim 6 and one axial end, here the upper end, of the second nut 2 and between an axial end, here the lower end, of the first nut 1 and the flange 8 at the second nut 2. According to the present invention, the gap 3 is now sealed to avoid that a liquid, e.g. a paint and/or coating, which is applied to a structure (not depicted), on which the tolerance compensating fastening means is attached, enters the gap 3. According to an inventive or preferred embodiment of the present invention, this sealing is executed by an overmould, which is applied to the first and second nut, preferably on the inner and outer circumference of the nuts 1, 2. Preferably, the first nut 1 comprises at its inner circumference form-fit-means 7, which is filled during overmoulding and hence leads to a form-fit-connection between the overmould 5 and the first nut 1. The overmould is preferably a plastic material, preferably Nylon. Furthermore, preferably, the overmould extends over the rim/flange 6, which may be part of the first nut 1. Furthermore, one or both ends of the gap, may be enlarged, e.g. by an indentation 4 in order to ensure that the gap is partially filled with overmould and/or that there is a form-fit between the overmould and the gap 3.

Figure 1a shows the tolerance compensating fastening means in its initial state after production. This embodiment corresponds to the embodiment shown in Figure 1. The first- and second nut 1 , 2 have been screwed together to an extend that the gap 3 and/or the axial extension of the tolerance compensating fastening means 11 is minimized. By rotating the first nut 1 relative to the second nut 2 the cooperation of the threads 9 will lead to an axial movement of the nuts 1,2 relative to each other, as can be seen in Figure 1b. This movement is carried out in order to compensate a tolerance, so that due to the rotation and hence the increase of the axial length of the tolerance compensating fastening means 11, both axial ends of the tolerance compensating fastening means 11 will come into contact with the structure in which the tolerance compensating fastening means 11 is inserted. From Figures 1a and 1b it can be clearly seen that the coating 5, here an overmould, seals the gap 3 fluid-tight, but does not hinder the axial movement of the nuts 1, 2 relative to each other. Due to the form-fit-connection 7 and the flange 6, the coating 5, here the overmould 5, moves, here upwards, together with the first nut 1.

According to an alternative or additional embodiment, the thread 9 between the two nuts is at least partially sealed. This sealing can be executed, by providing a substance, for example a grease, an adhesive and/or a liquid-repellent substance, into the thread 9 between the two nuts 1, 2. Preferably, the substance is liquid or semi liquid. Preferably, the substance is added prior to screwing the two nuts 1 , 2 together. The substance at least partially covers the surface of the thread 9. The sealing of the thread hinders for example water and/or a coating substance from entering into the thread 9 and/or to totally fill the thread 9 with for example water, a watery-substance and/or a coating substance, which may solidify there. In this case, the water, a watery-substance and/or coating substance may enter the gap 4 but not the thread 9.

Figure 2 shows the production steps of the tolerance compensating fastening means 11. According to steps a and b the first and second nuts 1,2 are provided and screwed together, here screwed together such that the gap 3 between the nuts 1 and 2 is as small as possible. This assembly according to step b is preferably inserted into the die of an injection moulding device and consequently, the coating 5, here the overmould, is applied around the nuts 1, 2, at the inner and outer surface, as depicted in step c. After the coating 5, here the overmould has been solidified the tolerance compensating fastening means 11 can be removed from the die. The coating 5, here the overmould 5, may comprise anti rotation means 10.

Figure 3 shows how the tolerance compensating fastening means 11 and composite body solution 18 are combined to the assembly means 19. The tolerance compensating fastening means 11 , preferably according to the present invention, is combined with a composite body solution 18, which comprises in the present case a carrier 12. Preferably, fastening means 14, here clipping means 14, can be utilized to fix the carrier 12 to a structure (not depicted), particularly a vehicle structure, e.g. a pillar. On top of this carrier an expandable material 13, preferably a thermo-expandable material is provided, preferably overmoulded. According to a preferred embodiment the composite body structure 18 comprises guiding means 15, which guides the expandable material during expansion. As can be seen from Figure 3 the two parts 11, 18 are combined, here by attaching the tolerance compensating fastening means 11 in an indentation of the carrier 12. The connection between the two parts 11, 18 is preferably by friction and/or a form-fit-connection.

The assembly means 19 are preferably produced by placing the assembled nuts 11, preferably being already coated for waterproofness in a mold, preferably automatically, for example by a robot. The carrier material to form carrier 12, preferably a Nylon carrier, is injected around the nuts 11 , preferably by maintaining a free-play. As a next or simultaneous step, expandable foam 13 is overmolded on the carrier 12, preferably in the same mould. Finally, the mould is opened and the assembly means including the nuts can be removed.

Figure 4 shows the assembly of a part 20 to a structure 17 utilizing the assembly means 19. In the present case, a roof rail 20 is attached to the roof of a vehicle. As can be seen according to Figures 4 a) and b), the assembly means 19, as for example depicted in Figure 3, is provided and fastened to a structure 17, here clipped to the structure. Optionally, as shown in Figure 4 c) the structure 17, particularly in case it is a pillar, is closed and then also optionally according to Figure 4 d), the structure is coated, here in an E-Coat bath. During curing of the coated structure in an oven, the assembly means is heated and thereby the thermo-expandable material 13 expands, which leads to the expanded material 16 as depicted in Figure 4 e). The expanded material 16 solidifies after expansion and hence provides structural support for the structure 17, e.g. to avoid bumps in the structure 17 during mounting and/or use of the part 20. According to step shown in Figure 4 f), the structure can be optionally painted and then according to Figure 4 g), a part 20, here a roof rail 20, is attached to the structure 17 by utilizing the tolerance compensating fastening means 11. Therefore, as shown in Figure 4 h), a fastening means 21, here a screw, is inserted into the inner hole of the nuts 1, 2 and is threaded into the overmould 5. Since the friction force between the fastening means 21 and the first nut 1, here the overmould 5, is higher than the friction force between the threads 9, the nut 1 will co-rotate together with the screw and hence, as explained according to Figure 1b, the gap between the first and the second nut 1, 2 increases as depicted by the arrow in Figure 4 j). This gap will increase until the upper portion of the outer overmould at nut 1 or the rim 6 is in contact with the structure 17. Due to the relative axial movement of the two nuts 1,2, a tolerance/gap between the upper and the lower part of structure 17 is filled out. In a final step, by further rotating the fastening means 21, here the screw, the part 20 is fixedly attached to the structure 17.

In Figure 5, reference is particularly made to the inner circumference of the overmould 5 at the inner circumference of the first and the second nut 1,2. As can be seen from this figure and also Figure 1, preferably the inner circumference comprises one or more longitudinal ribs, which particularly will be in contact with the thread of a fastening means 21 , particularly the thread of a screw.

Figure 6 show an alternative to seal the thread between the nuts 1, 2. Here, a sleeve 25 is pressed around the nuts 1 , 2 to seal the thread. The sleeve may comprise one or more lip(s) which are pressed into the gap(s) between the nuts 1, 2.

In the embodiment according to Figure 7, one or two O-ring(s) 26 is/are used to seal the gap(s) between the nuts. The O-ring is preferably made from a rubber material. The O-ring(s) may be in combination with or without the sleeve 25. One or both of the O-ring(s) may be substituted by a metal seal. The person skilled in the art understands that the thread can also be sealed and/or protected against the coating of the vehicle by a thread sealant which is applied to the thread for example by a paintbrush or the like.

Alternatively, the sealing can be realized by a bulge , for example a rubber bulge, which is applied to the gap(s) between the nuts or on a sleeve that surrounds on or both nuts. The bulge has preferably a circular shape. The bulge is preferably compressible.

List of reference signs:

1 first nut

2 second nut

3 gap, interface between nuts 1, 2

4 indentation

5 coating, waterproof coating, color-proof coating, overmould, thermoplastic material,

6 rim, flange

7 form-fit-connection

8 support flange

9 thread

10 anti-rotation means

11 Tolerance compensating fastening means

12 Carrier

13 Expandable material, layer of expandable material.

14 Fastening means, clipping means

15 Guiding means

16 Expanded material, expanded foam

17 Structure, vehicle structure, panel, cavity

18 Composite Body solution, CBS, reinforcement

19 Assembly means, CBS plus tolerance compensator

20 Part, part to be fastened, roof rail

21 Fastening means, screw

22 Ribs

23 Inner hole of the first nut

24 Cavity

25 Sleeve

26 O-ring

Claims

Claims:

1. Tolerance compensating fastening means (11), to be applied in or at a structure (17) with dimensions comprising a tolerance, the fastening means (11) comprising a first nut (1) with an outer thread (9) and a second nut (2) with an inner thread, wherein the two threads (9) interact such that a relative rotational movement of the two nuts (1 , 2) leads to an axial displacement of the nuts (1 , 2) relative to each other and wherein there is a gap (3) between the two nuts (1 , 2), characterized in, that the gap (4) and/or the thread (9) is at least partially sealed.

2. Tolerance compensating fastening means (11) according to claim 1 or the preamble of claim 1, characterized in, that the nuts (1, 2) are provided with a water- and/or coating-proof-coating (5) over the inner and outer surface of both nuts (1, 2) in the vicinity of the gap (4), respectively.

3. Tolerance compensating fastening means (11) according to claim 2, characterized in, that the coating (5) is a thermoplastic material, preferably polyamid.

4. Tolerance compensating fastening means (11) according to claims 2 -3, characterized in, that the first nut, preferably at the circumference of the inner opening comprises a form-fit-connection (7) with the coating.

5. Method to produce the tolerance compensating fastening means (11) according to one of the preceding claims, characterized in, that the assembled first nut (1) and second nut (2) are placed into a die of an injection moulding apparatus and that the gap (4) is coated and thereby sealed.

6. Assembly means (19) comprising tolerance compensating fastening means (11), preferably according to claims 1 - 4, to a structure (17), and a carrier (12) which holds the tolerance compensating fastening means (11), characterized in, that it supports a layer of expandable material (13).

7. Assembly means (19), characterized in, that the carrier (12) comprises an indentation, in which the tolerance compensating fastening means (11) is fixed, preferably clamped.

8. Assembly means (19) according to claim 7, characterized in, that the second nut (2) is fixed torque-proof to the carrier (12).

9. Assembly means (19) according to one of claims 6 - 8, characterized in, that layer of expandable material (13) surrounds the circumference of the circumference of the tolerance compensating fastening means (11) in a horizontal plane.

10. Method to fix a part (20) at a structure (17), utilizing assembly means (19) according to claims 6 - 9, characterized in, that

- the assembly means (19) and the tolerance compensating fastening means (11) are fixed into a cavity (24) of the structure (17),

- inserting and rotating a fastening means (21) in the hole of the first nut and thereby rotating the first nut (1) relative to the second nut (2) until the first nut and the second nut are in contact with sidewalls of the cavity, respectively and

- extending the fastening means into the part (20) until it is fixed to the structure (17).

11. Method according to claim 10, characterized in, that the expanded material reinforces the cavity (24).