FIELD OF THE INVENTION The present invention relates to a fastening device, used especially in vehicle doors where a set distance has to be maintained between the panel or lining and the plate or sheet metal of the vehicle, incorporating a nut or clip part, a bush part, and a key part, with the particular feature, inter alia, that said elements of the device have a pre-assembled position allowing the installation of the device rapidly from said position, thereby providing a fixed part and an extractable part that allows convenient re-use of the device after it has been detached.

BACKGROUND

There are numerous situations where fastening between a support or structure and a lining or panel has to be achieved, maintaining a set distance therebetween. This is the case in the automobile industry, for example, when fastening the lining to the chassis of the door of the vehicle. In such contexts, when stressed, conventional fastening means could give rise to the collapse of the panel by drawing it too close to the chassis. Requirements demand a leaktight fastening that is easy to install without tools, it being possible, in the event of detachment, for this operation to be easy and for the component not to be damaged and thereby require replacement .

European patent EP0921323 discloses a device for tackling this problem of joining a support to a plate element, in which provision is made for an intermediate region in the form of a neck that incorporates various retention elements, whereas, conversely, the coupling component incorporates linking elements antagonistic to the retention elements, with which it interacts in order to produce clearance compensation over the distance between said retention elements along said axle .

Patent EP0964170, meanwhile, relates to a device similar to the aforesaid, in which the inventive objective pursued lies in obtaining a pre-assembly position between the socket element and a bush that may be bolted hermetically therein in the sheet metal of the vehicle, which installation ultimately has to be supplemented with the addition of an element joining to the lining.

Patent EP1324898 proposes a joining element with adjusted extraction and insertion forces, which has a service position with crimping elements locked elastically and a use, or final, position. The joining element may be extracted whole for re-use by applying a sufficient extractive force allowing separation of the axle or key from the set of lower components, which loosens the flaring of said lower, or support, part, while a hood clamped at the end of the key entrains the support part and the assembly of the joining element outward . Some known devices allow rapid installation, starting from a service position of the parts that make up the fastening device, such that the operative's work is facilitated by taking the pre-assembled device and installing it in a simple operation, pressing against the bodywork. However, even with its advantages, in the prior art the join of the device to the bodywork and the panel is either difficult to re-use, normally because its extraction renders part of the device useless, or the device is extracted totally, without allowing the possibility of partial detachment, since elements of the device remain fixed, while re-use of the device is allowed, by separating the lining and allowing subseguent joining thereof. The principle subject matter of the present invention is therefore a device for fastening to a sheet metal element or support, the chassis of a vehicle, of a lining element, the panel of, for example, the door of a vehicle, which has a pre-as sembled, service position.

A further subject matter of the invention is that the installation of said device should be of the rapid type, starting from said pre-assembled, service position .

A further subject matter of the invention is that installation of the component gives rise to the fastening of a fixed part thereof, which in this operation is clamped to the chassis, such that the clip may be detached partially also, by extracting only the movable or key part thereof that fastens the lining.

A yet further subject matter of the invention is that said device should be leaktight once installed, incorporating means for sealing and rendering the installation hole hermetic.

These and other advantages of the present invention will become more apparent in the course of the description thereof, which follows.

BRIEF DESCRIPTION OF THE INVENTION The present invention relates to a device for fastening, between a structure or support and a panel or lining element, for example in vehicle doors, wherein a set distance between the panel or lining and the plate or sheet metal of the vehicle has to be maintained, which is formed by a nut-clip part, a bush part, and a key part.

The nut-clip part has an end face from which emerges a hollow cylinder, descending in the insertion direction thereof, which incorporates flexible means for retention and locking not only of the bush but also of the closure key. In the preferred embodiment of the invention, said retention means consist in the end thereof, which has the possibility of opening, being flared, forming flexible gripping clamps, and in locking catches or tabs formed in a window of said hollow cylinder, configured to act as a link with other antagonistic elements provided in the bush part.

The windows in the surface of said clip also have flexing and guide tabs on which engage, without the possibility of rotation or turning, guides provided on the surface of the bush. When said bush engages completely on the nut-clip in the use position thereof, these flexing tabs open, being flared, and represent an impediment to the extraction of the assembly upon abutment against the sheet metal of the vehicle.

The bush element is a hollow cylinder with an upper flange housed in that formed by the nut-clip part, having, on its outer surface, a perimeter ring and individual axles with linking elements, with at least two locking positions, and which form steps oriented over the perimeter, forming a grip lateral or tangential to said bush, being antagonistic vis a vis the catches of the clip described previously.

The key part has a stud-type axle which, at its end, has at least two regions that are stepped, in an annular manner, which interact with the clamps of the nut-clip part in order to lock, and at its other end two parallel surfaces, one configured in order to be on the exterior in application and the other delimiting a space between the two where the lining or panel to be fastened to the chassis is housed. Also incorporated is an enlarged intermediate region that delimits two annular grooves representing individual housings with the bush part in the service, or pre-assembly, and final use positions. The axle of the stud, at least from the upper surface, has a frustoconical shape which facilitates progressive insertion into the other parts of the device.

The device incorporates sealing gaskets, on the nut part, to ensure the hermetic nature of the assembly.

The material forming the device of the invention is plastics, within the prior art and in accordance with the specifications suited to said type of device, namely polypropylenes, polyamides, etc., incorporating elastomers, for example, in a proportion suitable for conferring flexibility on those parts that so reguire. For example, the sealing gaskets are made from a flexible material whereas, overall, the device is made from hard plastics; the clamping or movable elements incorporate an elastomer mixture to allow a degree of flexibility without the breakage of the material. All the components may optionally be produced from the same material. All the aforesaid in accordance with the technigue used in the production of plastics materials for fastening devices.

The components may be constructed by molding, which facilitates the production of complicated geometrical shapes without raising the manufacturing unit cost thereof .

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the invention, the present description is accompanied by four sheets of drawings, which are provided solely by way of illustration and do not limit the invention. Figure 1 is a perspective representation of a device according to one of the possible embodiments of the present invention, without sealing gaskets and assembled in its use position, in which the lining or panel and the chassis or support of said fastening have been dispensed with.

Figure 2, however, is a representation similar to that of the preceding figure, showing the sealing gaskets, the chassis of the vehicle and the installation casing in the panel.

Figure 3 corresponds to a front view of the nut-clip part of the device, in accordance with the embodiment shown in the preceding figures.

Figure 4 is a lateral view of the preceding figure.

Figure 5 is a cross-sectional view according to figure 4.

Figure 6 is a top perspective view of the nut-clip of the preceding figures, but without the sealing gasket. It is possible to see the reinforcement of the inner face of the flexible claws of said component.

Figures 7 and 8 are two perspective representations of the bush part of the device of the present invention shown in the preceding figures.

Figure 9 is a front view of the key part of the device of the preceding figures .

Figures 10 and 11 show cross sections of the device of the invention in one of its preferred embodiments, incorporating the sealing gaskets, presented in a pre- assembled, or service, position. These are two sectional views taken along orthogonal planes and corresponding to two sides of the assembly. Figures 12 and 13 are representations similar to the preceding two figures, but now with the assembly in its installation, or service, position.

DETAILED EXPLANATION OF THE INVENTION

The present invention relates to a fastening device of the type that form a join between a structure or support and a lining or panel element, for example in vehicle doors, wherein a separation distance between the panel and the sheet metal of the vehicle has to be maintained, which is formed by a nut-clip part (1), a bush part (2), and a key part (3) .

The nut-clip part is formed by a hollow cylinder (16) that at one end has a surface (11), in the manner of a flange, which extends over the perimeter, and at the other end has notches or recesses that allow respective fingers (12) to have an elastic capacity to open and be housed in lock elements arranged on the key part (3) .

The surface of said tubular or cylindrical body (16) has voids or windows (13) of approximately "U" shape that configure a flexing, guide tab or claw (15) . The inner perimeter of said window (13) incorporates a catch (14) oriented laterally, i.e. in a direction tangential to said cylinder (16), said catches (14) designed to lock and retention elements provided in the bush part ( 2 ) .

At the end of said flexing tabs (15) are bends or fingers (18), as may be seen easily in the cross section of figure 5, directed to the center of said nut-clip (1). This construction principally allows, upon insertion of the bush (2) in said nut-clip (1) in its final use position, by means of mechanical pushing against the fingers (18), the flexing tabs (15) to open outward from the nut-clip (1), giving rise not only to locking between said nut-clip (1) and said bush (2) but also the fastening of this assembly in the chassis of the bodywork of the vehicle, and thus said flexing tabs (15) are now a stop that impedes extraction.

On their inside, said flexing tabs (15) may incorporate reinforcements (19), as shown in figure 6.

The bush part (2) is also a hollow cylinder and incorporates in the outer surface of said cylinder (25) individual guides (22) and at least two steps (23 and 23 ' ) arranged laterally therein and configured in order to offer at least two locking positions, i.e. a service and a final position, with the antagonistic elements provided on the clip-nut part, i.e. the catches (14) .

There may also be a reinforcing rib (24) that acts as downward stop for the bush, in the form of a ring that consolidates said guides (22) and said locking steps (23, 23') . At the bottom there may be a recessed perimeter (27) for improving the elastic response of this part of the component. In the preferred embodiment shown in the drawings, windows (26) have been provided. The key part (3) has an axle or stud (31) on which, in the proximity of the end (32) of which, it has at least two annular grooves (36, 36') for the clamping of the flexible fingers (12) arranged at the end of said nut- clip (1) .

At the other end of said key (3) are the cap or end face (34) thereof and, at a certain distance therefrom, a support surface (33). The axle (31) of the key part (3) has at least, from the end face (34), a general frustoconical shape, being narrower in cross section at the tip (32) than in the region close to the planar surface (33) . This represents a progressive tapering of said axle (31), which facilitates its insertion into the other parts (1 and 2) of the device of the invention.

Said axle (31) also has various bulges that delimit annular grooves or depressions. Specifically, two such annular depressions or grooves (36, 36') are provided in the region of the tip (32) of the axle, and two more (37 and 37') at a distance from the preceding two. These grooves allow flexible locking of other antagonistic elements provided on the other parts (1 and 2) of the device, as explained below, in the service position and in the application position.

The invention envisages the use of sealing gaskets, for example the sealing gasket (17) of the nut-clip (1), which has suitable notches for housing thereof, these gaskets being produced from flexible material.

In a known manner, the upper surface (34) of the key part (3) incorporates a tolerance mechanism or centering mechanism for the component comprising an outer collar joined to the central axle by flexible means, which, once the key (3) has been installed, allows a degree of lateral clearance movement of the axle (31) of said key, for the purpose of locating the installation hole in the bodywork.

As may be inferred from the above structural details of each part (1, 2, and 3) of the device and from the drawings accompanying the present invention, the latter is a fastening device for maintaining a set distance between a support element and another, lining, chassis and panel, element of, for example, the door of a vehicle, having a service position in which the three parts are pre-as sembled in a stable position that cannot be separated unintentionally, said position being the starting point for easy installation.

Installation of the device could not be simpler. Although there may be various forms of installation, depending on the installer's preferences, one of these is to fasten it from the pre-assembled or service position in the panel or lining and to press it against the hole provided in the bodywork or chassis for fastening thereof. The force of application or thrust provided by the key (3) that moves the assembly towards the inside of the location hole gives rise, promoted by the frustoconical form of the axle (31) thereof, to locking of the three parts (1, 2, and 3) in their installation position in which the fingers (12) of the nut-clip move from the groove (36) to the groove (36') of the key. Meanwhile, in the relation between the bush (2) and the nut-clip (1), there is a movement of the catch (14) of the nut-clip (1) from the first step (23) of the bush (2) to the step (23') of the installation position. This process is guaranteed or led by the tab or claw (15) that acts as stop between two guides (22) of said bush (2), preventing a rotation or turning movement between the two components.

In this position, the fingers (18) are pushed outward, opening the flexing tabs (15); the flaring of said tabs (15) guarantees the join between said nut-clip (1), with the aid of the bush (2), in fastening the assembly to the bodywork of the vehicle, preventing the extraction thereof.

These tabs (15) have, in their inner part, on the inner face of the component, a structural reinforcement (19). In the bush part (2), the windows (26) thereof allow space for said structural reinforcement (19) in the pre-assembled position of the assembly, without flaring the tabs, as shown in figure 11.

The assembly of the various components (1, 2, and 3) of the device is produced in plastics of suitable type and properties, in accordance with the known technique pertaining to fastening elements, the selection of materials being suited to the present purpose.

By virtue of the structural nature of the device of the present invention, an assembly has been made possible that has, between its parts, a pre-installation position that is easy to use as far as its final application position and in the event of requiring removal allows partial detachment thereof, since the nut-clip (1) and bush (2) assembly remains fastened in the chassis of the vehicle, allowing the removal of the key (3) from said join and the removal of the panel without having forcibly to recover the whole clip that now provides a clamping point for the new fastening of the key and installation of the lining.

Obviously, the present case may include such variations in details of finish and form as do not adversely affect or modify the essential nature of the invention.