Patent Description:
Fasteners can be used to retain two components together. Such fasteners and fastening arrangements are for example used in automotive industry for fastening trim parts and attached parts to the vehicle body or to body parts such as doors and the like. For example, fastener clips can be used to retain an automotive door or trim panel to an automotive doorframe or support surface. The fastener clips can engage with a hollow portion, commonly called "dog house" assembly in or on the door panel and can be inserted through an opening in the doorframe to retain the panel on the doorframe. Fastening there should be accomplished in the simplest possible manner and without the use of tools (or only few).

Various fasteners of the specified type are known for example from <CIT>, <CIT> or <CIT>. The prior art fasteners have in common that an element in the shape of a stud is provided as the connecting part and is joined to the support part in a latching manner by insertion through an opening in the support part.

In <CIT>, the fastener is a two-part fastener comprising a first part with a stem and a flange and an extension sleeve made in a first material with a second material partly overmolded. The second material forms a sealing element or sealing sleeve which continuously extends from a flange to a portion of the shank of the sleeve. The use of this fasteners may be burdensome with the two elements. Besides, the manufacture is complicated. <CIT>, <CIT> and <CIT> also disclose fasteners made of two different materials.

The object of the present invention is to go some way towards solving or at least mitigating the problem above and providing a fastener allowing easy manufacture and manipulation with dismounting possibilities and adjustable mounting and dismounting forces. The object of the present invention is further to provide a fastener avoiding or lowering the risks of paint scratches or paint abrasion.

To this aim, according to the invention, it is provided a fastener for attaching a panel to a frame according to claim <NUM>.

The mounting and dismounting forces of such fasteners can be adjusted through the second plastic material. Indeed, the position of the second plastic material, notably overmolded on the engaging member allows to adjust the mounting and dismounting forces by adjusting the thickness of the material. Besides, the position of the second plastic material extending at the perimeter of the flange and over the engaging member allows to protect all the parts of the body element which are possibly in contact with the panel or the frame to be covered by a softer material and thus lowering the risks of paint scratching or abrasion.

In some embodiments, the free end of the stem comprises a first segment having a first conical shape and a second segment having a second conical shape, wherein the second segment extends between the first segment and the flange, and wherein the support element is overmolded on the second segment, the base of the first conical shape of the first segment forming an abutment for the support element overmolded on the second segment. The two cones shape at the free end of the stem is particularly convenient to form an abutment portion and a recess portion for the second plastic material. The distal end of the stem stays uncovered, allowing easy manufacture of the fasteners.

According to the invention, each engaging member comprises a free end directed toward the internal surface of the flange, and wherein a protrusion is arranged on the free end, so that the protrusion forms an abutment for the support element on the engaging member. The protrusion clearly delimits the support element.

In some embodiments, the support element overmolded on the engaging member further comprises flaps extending sensibly parallel to the flange from the protrusion. The flap entirely made in the second plastic material (soft material) thus reduces the risks of scratch. During dismounting, the flap is retracted so that several mounting and dismounting steps are possible.

In some embodiments, two engaging members are provided, and wherein the stem has a rectangular cross section. Such design is easy to manufacture. Besides, the rectangular cross section of the stem allows a better positioning of the engaging members.

In some embodiments, the grip portion comprises a first segment extending from the external surface of the flange with a restricted cross section, and a second segment extending from the first segment having an arc-shaped body.

In an alternative embodiment, the grip portion comprises a first segment extending from the external surface of the flange with a restricted cross section, and a second segment extending from the first segment parallel to the flange.

In some embodiments, the rim is a stepped rim. The stepped rim is easy to manufacture and can be overmolded such that the support element extending at the peripheral of the flange can partly freely extend and form a non-zero angle with the flange.

In some embodiments, the support element is overmolded on a portion of the stem. More particularly, the support element is overmolded on an external portion of the rim.

According to another embodiment of the invention there is provided a fastening arrangement with a fastener as described above, a frame comprising a slot and a panel, wherein the panel comprises a hole, the frame comprises a slot.

Other characteristics and advantages of the invention will readily appear from the following description of embodiments, provided as non-limitative examples, in reference to the accompanying drawings.

On the different figures, the same reference signs designate identical or similar elements.

<FIG> and <FIG> show a fastener <NUM> according to a first embodiment of the present invention. The fastener <NUM> comprises a body element <NUM> made in a first plastic material and a support element <NUM> made in a second plastic material. The second plastic material is softer (or less rigid) than the first plastic material. It is to be understood that the first plastic material is more rigid than the second plastic material. In other words, the second plastic material has an elasticity which is superior to the first plastic material's elasticity, avoiding thus to scratch painting for instance. The second plastic material is more compressible than the first plastic material. The first material is for example a PA66, PA6 or POM, wherein the second plastic material can be a TPE material.

The body element <NUM> comprises a flange <NUM> having an internal and an external surface opposite the internal surface, the flange <NUM> being flat. The flange <NUM> thus extends along a plane and has a rim <NUM>. The body element <NUM> further comprises a stem <NUM> extending from the internal surface until a free end portion <NUM>. The free end portion <NUM> of the stem <NUM> (or portion of the stem distal from the flange <NUM>) has a conical shape. A grip portion <NUM> is arranged on the external surface of the flange. Engaging members <NUM>, <NUM> extending from the stem <NUM> and expanding obliquely upwards toward the internal surface of the flange <NUM> are arranged on the stem <NUM>.

The grip portion <NUM> comprises a first segment extending from the external surface of the flange with a restricted cross section, and a second segment extending from the first segment having an arc-shaped body.

The support element <NUM> is overmolded on the rim <NUM> of the flange <NUM> and extends externally forming a spring collar <NUM> extending at the perimeter of the flange <NUM>. The spring collar forms a non-zero angle with the flange <NUM>. The spring collar <NUM> is entirely made in the second plastic material, so that the spring collar <NUM> is not rigid. Actually, the spring collar <NUM> is retained on the flange only through overmolding on the rim <NUM>. The rim <NUM> can be a stepped rim, such that an elbow is formed between the internal and the external surfaces on the lateral side of the flange <NUM>. The elbow forms an abutment for the support element.

The support element <NUM> is further overmolded on the engaging members <NUM>, <NUM>. The support element <NUM> may be discontinue, such that the support element <NUM> overmolded on the engaging members <NUM>, <NUM> does not interact with the support element <NUM> overmolded on the rim <NUM> of the flange <NUM>.

In another embodiment, the support member <NUM> is further overmolded on a portion of the stem. For example, as depicted <FIG>, the support element <NUM> is overmolded on a surface of the stem visible from the outside (or an outer surface). A first overmolded portion extends from flange and is less wide than the stem, whereas a second overmolded extends from the first overmolded portion and covers the thickness of the stem. Thus, in the vicinity of the flange, the support element on the stem is longitudinally delimited on both side by the first plastic material.

The fastener is a one-piece element. The engaging members may have interlock portions I (as shown in <FIG> for instance) which allow a better adhesion of the support element <NUM> during the overmolding step. The interlock portions I may comprise one or several grooves or other geometrical shape allowing the adhesion. In another embodiment, the interlock portions may comprise ribs less wide than the engaging element and provided at the end of toward the end of the engaging members.

The engaging members <NUM>, <NUM> extends from a portion of the stem <NUM> which is between the flange <NUM> and the free end portion <NUM>. The engaging members <NUM>, <NUM> comprise each an internal surface facing the stem and an external surface opposite the internal surface. As seen on the figures, the fastener <NUM> comprises two engaging members. However more engaging members might be arranged on the stem.

The stem <NUM> has for instance a rectangular cross section, and the engaging members <NUM>, <NUM> are arranged on the long side of the rectangle. The engaging members <NUM>, <NUM> each comprise a free end directed toward the flange <NUM>. The free end is provided with a protrusion <NUM>, as seen on <FIG>. The protrusion forms an abutment for the support element <NUM>. The interlock portions may be arranged in the vicinity of the protrusion <NUM>.

The support element extends on the engaging members <NUM>, <NUM> on their external surface and from the protrusion toward the free end of the stem, without extending on the free end of the stem. The support element <NUM> can be further overmolded on the short side of the stem. In other words, the support element is overmolded on the external side of the stem.

The distal end of the stem <NUM> comprises a first conical shape S1 and a second conical shape S2. The first conical shape S1 corresponds to the portion the most distal from the flange <NUM> and is not covered by the support element <NUM>. The base of the first conical shape forms however an abutment for the support element <NUM> provided on the engaging member. Besides, the second conical shape forms a recess for the support element such that the support element can extend from the base of the first conical shape to the protrusion seating relatively flush with the free end portion <NUM> of the stem.

In a second embodiment, which is not part of the invention, depicted in <FIG>, the support element <NUM> is overmolded entirely at the external surface of the engaging members. More particularly, the support element <NUM> covering the engaging members <NUM>, <NUM> extend from the base of the first cone until the free end of the engaging members directed toward the flange <NUM>.

In a third embodiment depicted in <FIG>, the support element <NUM> covering the engaging portion extends from the base of the first cone shape to the protrusion and then further extends radially outside from the stem, such as to form flexible flaps. The flaps may extend sensibly parallel to the flange <NUM>. The rest of the fastener is similar or identical to the first or second embodiment.

In the fourth embodiment, which is not part of the invention, depicted in <FIG>, the grip portion <NUM>' comprises a first segment extending from the external surface of the flange with a restricted cross section, and a second segment extending from the first segment parallel to the flange. The rest of the fastener is similar or identical to the first or second embodiment.

The engaging members <NUM>, <NUM> form latches which can be retracted by introducing the fastener in an opening provided on a panel.

<FIG> shows a fastener according to the first embodiment in an assembled state with a frame (or rail). The frame (which is actually a rail) comprises a slot and the first segment of the grip portion with the restricted section extends in the slot, wherein the second segment of the grip portion extends on the upper side of the frame. The frame is thus sandwiched between the second segment of the grip portion and the flange.

The fastener arranged in the frame is then mounted to the panel, as seen in <FIG>.

<FIG> shows a fastening arrangement. The fastening arrangement comprises a fastener, a panel and a frame. The panel is provided with a hole, in which the stem and the engaging members can be introduced. The underside of the frame faces the upper side of the panel. During the introduction of the fastener inside the hole, the engaging members <NUM>, <NUM> are retracted such as to be inserted in the hole. The support element is in contact with the fastening surface, such that no paint scratching is provided. After insertion, the engaging members elastically expand such that the free end of the engaging member can abut on the underside of the panel. The flange and the spring collar extend on the upper side of the panel. The flange and the spring collar are sandwiched between the panel and the frame. Here again, due to the position of the support element, paint scratching is limited.

Claim 1:
Fastener (<NUM>) for attaching a panel to a frame comprising:
a) a body element (<NUM>) made in a first plastic material and
b) a support element (<NUM>) made in a second plastic material,
the second plastic material being less rigid than the first plastic material,
the support element being at least in part overmolded on the body element, wherein
the body element comprises
- a flange (<NUM>) having an internal and an external surface opposite the internal surface, the flange (<NUM>) being flat and having a rim (<NUM>),
- a stem (<NUM>) extending from the internal surface until a free end portion (<NUM>), wherein the free end portion of the stem has a conical shape,
- a grip portion (<NUM>) arranged on the external surface of the flange
- engaging members (<NUM>, <NUM>) extending from the stem and expanding obliquely upwards toward the internal surface of the flange, the engaging members (<NUM>, <NUM>) having an internal surface facing the stem and an external surface opposite the internal surface,
wherein the support element (<NUM>) is overmolded on the rim and extends externally forming a spring collar extending at the perimeter of the flange and forming a non-zero angle with the flange, and wherein the support element is further overmolded on the engaging members,
wherein each engaging member (<NUM>, <NUM>) comprises a free end directed toward the internal surface of the flange (<NUM>), characterized in that a protrusion (<NUM>) is arranged on the free end, so that
the protrusion (<NUM>) forms an abutment for the support element on the engaging member (<NUM>, <NUM>), and wherein the support element (<NUM>) extends on the engaging members (<NUM>, <NUM>) on their external surface and from the protrusion toward the free end of the stem, without extending on the free end of the stem.