TECHNICAL FIELD

The present invention relates to a retaining device, in particular for connecting vehicle body parts to one another.

BACKGROUND ART

It is known that retaining devices of various type, of the snap-fit or bayonet type, are used in the automotive field, in order to obtain the reciprocal fastening of body parts, e.g. an interior finishing panel to the frame of a door or of a side panel of the passenger compartment of a vehicle.

For example, a retaining device is known from KR20110049216, consisting of a bearing element made of plastic material and provided with a head and an elastically deformable shank adapted to engage a seat carried by the vehicle body or by another intermediate part, provided with a deformable washer applied onto the head.

Problems of detachment of the washer from the head may occur even in the preferred case in which the washer is co-molded onto the head. Furthermore, the retaining device itself is intended to be used to fix panels or finishing elements onto sheets of different thickness, as would be desirable in order to obtain scale economies, which results in the head/washer assembly being either too flexible or not flexible enough, thus creating the risk of partial detachments or assembly problems.

These drawbacks are even more severe when it is considered that the panels are to be removed several times for maintenance without breaking the retaining devices or loosening the retaining force, which events could give rise to annoying noises in use when the vehicle is running.

DISCLOSURE OF INVENTION .

It is an object of the present invention to overcome the drawbacks of the prior art by providing a reliable and relatively cost-effective retaining device of simple construction and small dimensions which allows panels or other finishing parts of different thickness to be fixed to the vehicle body with equal efficiency.

The present invention thus relates to a retaining device as specified in claim 1.

In particular, the retaining device according to the invention comprises a bushing-shaped bearing element, in turn comprising a flanged head and - a shank, which overhangingly extends from the head along a common axis of symmetry, and an elastically deformable, compressible sucker integrally carried by the flanged head so that at least part of the head is embedded within a thickness, measured in an axial direction, of the sucker.

The flanged head is also sucker-shaped as it is delimited by a pair of opposing conic-truncated surfaces, a front surface facing the shank and a rear surface, respectively, which are coaxial to each other and to the common axis of symmetry of shank and head, and by a radially outermost side edge, which delimits the head on the opposite side from the shank; the head instead is delimited, radially toward the interior, by an annular root portion which is integrally obtained in one piece with the shank.

According to an aspect of the invention, the head is provided with respective axial through apertures arranged in a circle, about the common axis of symmetry and which extend through the front and rear surfaces of the head; and at least at some of these axial through apertures, the head is provided with radial slots which extend through the head in an axial direction and which each extend from a corresponding axial through aperture and toward the radially outermost side edge up to interrupt the latter in a circumferential direction.

According to a further feature of the invention, the width measured in a circumferent-i-al—direction of the axial through apertures is greater than that of the radial through slots. Furthermore, the head is preferably provided with a radial through slot for each axial through aperture present on the head, so that the head, from a top plan view, appears as an annular-shaped element provided with a plurality of fan-shaped radial petals separated on the head by the axial apertures and corresponding radial slots, which are obtained through a radially outer annular portion of the head.

Thereby, on the one hand, the flexibility of the flanged head is increased in a controlled manner at the outer edge thereof, and on the other hand coupling elements are created, consisting of the slots and corresponding apertures, which allow the sucker to be safely restrained to the head, and above all make the sucker capable of cooperating with the head during the elastic deformations that they both undergo in use, thus behaving as a single element.

The sucker is preferably co-molded onto the head using an elastomeric material or one with equivalent properties (e.g. silicone or silicone rubber), and the whole bearing element is molded from synthetic plastic material .

The generation of annoying noises is also avoided and a substantially constant retaining force of the device is obtained.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages of the present invention will be apparent from the following description of a preferred embodiment thereof, merely provided by way of non-limitative example, with reference to the accompanying drawings, in which:

- figure 1 shows an orthogonal, elevation view of a retaining device provided according to the invention;

figure 2 shows a section view taken along a plotting line II-II of the device in figure 1 on enlarged scale;

- figure 3 is a top plan view of a bearing element of the retaining device in figure 1;

figure 4 shows a perspective, three-quarters front view of the bearing element in figure 3 on reduced scale; and

- figure 5 shows a detail of figure 3 on enlarged scale .

BEST MODE FOR CARRYING OUT THE INVENTION

With reference to figures from 1 to 5, reference numeral 1 indicates a retaining device as a whole, particularly adapted to connect vehicle body parts (known and only diagrammatically shown in figure 2 for simplicity) to one another, the parts consisting, for example, of a first vehicle body part consisting in turn, for example, of a panel or other finishing part 5, of which a (known) fastening turret is shown diagrammatically and only in part, and of a second vehicle body part 4, consisting of a part of the vehicle body and intended to integrally receive the body part 5, by means of one or more devices 1 and a series of pins 5b (known and only diagrammatically shown for simplicity), e.g. of the bayonet-type, which are fixed in a known manner to part 5 and which are then snappingly introduced into device 1, generally bushing- shaped and already snappingly fixed to part 4.

Device 1 comprises a bearing element 2, bushing- shaped as a whole, made of an elastically deformable, but relatively rigid material, such as a synthetic plastic material, filled or not, and elastically deformable, compressible annular sucker 3, made of a material having a lower rigidity than the material of the bearing element 2, e.g. an elastomer or a material having equivalent softness and elasticity properties, e.g. silicone.

The bearing element 2 (figures 3 and 4) comprises, in turn, an annular flanged head 6 adapted to be abuttingly coupled in use against the body part 4, as diagrammatically shown in figure 2, and a shank 7, which overhangingly extends from the head 6 along a common axis of symmetry A and is adapted to be coupled in use to a through seat 8 (known) of the body part 4 in order to block device 1 onto part 4 in a known manner.

Sucker 3 is integrally carried by the flanged head 6, so that at least part of head 6 is embedded within a thickness, measured in an axial direction, of sucker 3, which is thus interposed in use between the flanged head

6 and the body part 4, as di _j grammatically shown in figure 2.

The flanged head 6 is also sucker-shaped, as it is delimited by a pair of opposing conic-truncated surfaces

9, a front surface facing the shank 7 and rear surface

10, respectively, which are coaxial to each other and to the common axis of symmetry A of shank 7 and head 6, and by a radially outermost side edge 11, which delimits head 6 on the opposite side from shank 7; indeed, head 6 is radially delimited toward the interior by an annular root portion 12 opposite to edge 11, which annular root portion is integrally obtained in one piece with shank 7.

In the non-limitative example shown, shank 7 is made as a cylindrical sleeve, thus empty inside to receive in use and in a known manner pin 5b, laterally provided with elastically deformable teeth 13 (known) for snap-fitting into seat 8, but for the purposes of the invention, it may have any shape and structure and be coupled in seat 8 in any known manner, either of the snap-fit or bayonet or any other type. Furthermore, as described below, device 1 may be even used to directly couple parts 4 and 5 to each other without using pin 5b, as obvious for a person skilled in the art.

According to one of the features of the invention, head 6 is provided with respective axial through apertures 14 arranged in a circle about the common axis of symmetry A and which extend through both the front 9 and rear 10 surfaces of head 6, and thus... through- the - entire thickness of head 6 measured in an axial direction; according to the invention and in combination with the presence of the apertures 14, head 6 is provided with respective radial slots 15 at some of the apertures 14 at least, (and at all the apertures 14 in the preferred embodiment shown) , which slots extend in an axial direction through head 6 'and which each extend from a corresponding axial through aperture 14 and toward the radially outermost side edge 11 up to interrupt the edge 11 itself in a circumferential direction.

The radial slots 15 are rectilinear and the radially outermost side edge 11, when looking at the head 6 from the top in plan view (figure 3), has a substantially circular shape (circular, in the example shown), or however generally curved, e.g. oval or elliptical as well.

Furthermore, according to the invention, the width of the axial through apertures 14 measured in a circumferential direction is greater than the width, measured in the same circumferential direction, of the radial through slots 15.

If head 6 is provided with a radial through slot 15 for each and every axial through aperture 14 on head 6 (as in the preferred embodiment shown) , the head 6 seen in a plan view (figure 3) appears as an annular-shaped element provided with a plurality of fan-shaped radial petals 16 separated on head 6 by the axial apertures 14 and corresponding radial slots 15; slots 15 and apertures 14 are indeed obtained through a radially outer annular portion 17 of head 6.

When looking at head 6 from the top in plan view, the axial through apertures 14 each have a substantially square shape (figure 5) with rounded vertices, delimited by four rectilinear sides 18,19,20,21 joined by curved join stretches 22, where the side 21 facing the radially outermost side edge 11 of the head is completely interrupted by a corresponding slot 15, except at the respective curved join stretches 22, so that each aperture 14 defines, with a respective slot 15 corresponding thereto, a single radial recess 23 (figure 5) obtained through the radially outermost side edge 11 of head 6, having a substantially exclamation mark shape, when looking at the head from a top plan view.

The opposing front 9 and rear 10 conic-truncated surfaces (figure 2) preferably have a different angle of conicity such that the flanged head 6 becomes thinner in an axial direction, progressively tapering as it moves radially away from the axis of symmetry A toward the radially outermost side edge 11.

Moreover, again to increase the elasticity of device 1 in a controlled manner, sucker 3 has a peripherally outer annular portion 24 which covers, by completely incorporating it, the radially outer annular portion 17 of the flanged head 6 provided with apertures 14 and slots 15; an end 25 of the annular portion 24, which is radially outermost than the portion 24 itself, radially overhangingly extends from edge 11.

Furthermore, such a peripherally outer annular portion 24 of sucker 3 is provided, on the side of the conic-truncated front surface 9 of the flanged head 6, with a plurality of holes or depressions 26, preferably circular in shape, arranged in a circle about the axis of symmetry A; a peripherally inner annular portion 27 of the sucker covers the root portion 12 of head 6 and is connected to the peripherally outer annular portion 24 by means of a plurality of radial straps 28, so as to leave the parts of head 6 uncovered on the side of surface 10. In addition, in diametrically opposite position, portion 12 is provided with two protrusions 19 having a circular crown sector shape in plant view, which improve the connection between sucker 3 and head 6.

According to the invention, the above-described device 1 is made of two co-molded parts consisting of the bushing-shaped bearing element 2, which is first obtained by injection molding, and of sucker 3 which is co-molded in the aforesaid elastomeric material or in a material having equivalent features, directly over the flanged head 6.

By virtue of the described structure, sucker 3 cooperates with head 6, and vice versa, appropriately distributing deformation stresses therebetween, and creating a synergistic effect which considerably improves the operation of the device 1 as a whole, thus always ensuring a correct pressure on part 4, regardless of the thickness of the latter, so that the device 1 itself may be used to fix a part 5 onto parts 4 having a different thickness and thus belonging to many different vehicle models, again with excellent results and allowing to obtain high scale economy.