Decorative functional component having a transparent partial surface

A decorative functional component with a transparent partial surface includes a substrate and a flat cover body. The substrate is of a first plastic material and has a recess. The cover body is of a transparent second plastic material and covers the recess of the substrate. The substrate and the cover body are connected together by a loose form-fit connection. The substrate and the cover body and are jointly coated with a low viscosity curing transparent plastic flooded thereon.

TECHNICAL FIELD

The present invention relates to a decorative functional component with a transparent partial surface, the decorative functional component including a plastic substrate and a flat cover body, the plastic substrate being made of a first plastic material and having a recess, and the cover body being made of a transparent second plastic material and covering or filling the recess of the plastic substrate.

BACKGROUND

Components that are manufactured as two-component, injection-molded parts are known that acquire a transparent partial area or a completely transparent molded part, possibly back-molded behind a decorative film, which in a further step is partially or fully back-molded. These components contain high mechanical stresses.

A functional component having a viewing window in a housing is known from German Patent application DE 10 2006 048 550 A1. The housing and viewing window are designed as a two-component injection-molded part, with adjoining edges of the housing and the viewing window having a tongue and groove joint.

It is preferably provided that the plastic material of the viewing window is slightly melted in the area of the tongue and groove joint and forms a tight material bond with the material of the housing. Such a tight material bond is advantageous when the viewing window in particular is to be framed into the housing in a liquid-tight manner. However, mechanical tensions that influence the optical properties of the viewing window are unavoidable.

This is disadvantageous in particular when the viewing window is to be situated in front of a display whose appearance may thus be impaired.

In addition, for many applications it is undesirable for a viewing window to be discernible as a particular or special area of a functional component.

SUMMARY

An object is to provide a generic functional component in a simple manner while largely avoiding the disadvantages stated above.

In embodiments of the present invention, a decorative functional component with a transparent partial surface includes a plastic substrate (or plastic carrier) and a flat cover body. The plastic substrate is made of a first plastic material and the cover body is made of a transparent second plastic material. The plastic substrate has a recess. The cover body covers or fills the recess of the plastic substrate. The plastic substrate and the cover body are joined by a loose locking fit and are jointly coated, by flooding, with a low viscosity curing transparent plastic.

Embodiments of the present invention achieve the above object and/or other objects in that the plastic substrate and the cover body are joined together by a loose form-fit connection and are jointly coated with a low viscosity, curing (or hardening), transparent plastic by flooding.

A “loose form-fit connection” is understood to mean a form-fit arrangement of components whose mechanical connection is intentionally designed with play.

Embodiments of the present invention thus provide, firstly, to mechanically decouple the two joined components (i.e., the plastic substrate and the cover body) in order to prevent mechanical stresses, and secondly, to overmold these two joined components in a further step using a transparent elastic compound, preferably a polyurethane, in order to form or cover the surface of the functional component in such a way that the separate arrangement of the two components is optically concealed. The transparent plastic layer that adheres to both the plastic substrate and the cover body also affixes these two components to one another without thereby building up mechanical stresses between them.

DETAILED DESCRIPTION

Referring now toFIG.1,FIGS.2aand2b, andFIGS.3a,3b, and3c, a decorative functional component in accordance with a first exemplary embodiment will be described. The decorative functional component includes a plastic substrate (or plastic carrier)11.FIG.1illustrates plastic substrate11in cross-section. As shown inFIG.1, plastic substrate11includes a recess13. Plastic substrate11is injection-molded from a first plastic material. Plastic substrate11, illustrated schematically, may be part of a housing or an operator panel.

The decorative functional component further includes a cover body12.FIG.2aillustrates a first design variant of cover body12andFIG.2billustrates a second design variant of cover body12′. Cover body12,12′ is transparent. Particularly, cover body12,12′ is either fully transparent, semi-transparent, or partially transparent. Like plastic substrate11, cover body12,12′ is also manufactured by injection molding. However, cover body12,12′ is injection-molded from a second plastic material different than the first plastic material.

As shown inFIGS.2aand2b, cover body12,12′ has clip hooks15,15′. Clip hooks15,15′ allow a loose form-fit connection of cover body12,12′ to plastic substrate11. The outer spacing of clip hooks15,15′ intentionally has a smaller design than the associated cross section of recess13of plastic substrate11, so that after being clipped in, cover body12,12′ is situated at plastic substrate11with play and free of mechanical stresses.

Cover body12,12′ may already be provided with printing53prior to the mounting. Design print, color print, and also functional electrically conductive print may be imprinted on the top side or bottom side of cover body12,12′. The cover body may be manufactured either in one piece (FIG.2a) or as an overmolded or back-molded film (FIG.2b). The film may in particular be a functional film51having electrical sensors or display elements (not shown). It is indicated that functional film51has an electrical connection52.

FIGS.3a,3b, and3crespectively illustrate first, second, and third mounting steps for producing the decorative functional component in accordance with the first exemplary embodiment. Cover body12illustrated inFIGS.3a,3b, and3cis provided to form a transparent window within plastic substrate11. For this purpose, cover body12is clipped with its clip hooks15into recess13of plastic substrate11, per the first mounting step shown inFIG.3a. The joined components (i.e., cover body12joined to plastic substrate11) are subsequently jointly flooded using a transparent low-viscosity liquid that cures to form a transparent plastic layer14, per the second mounting step shown inFIG.3b. A polyurethane is preferably provided as flooding material.

When the first plastic material of plastic substrate11and/or the second plastic material of cover body12does not adhere to the low viscosity liquid (or does not take up any flattening to the low viscosity liquid), the surfaces of plastic substrate11and of cover body12may advantageously be provided with an adhesion promoter beforehand.

The window created by cover body12within plastic substrate11is preferably provided to allow a view of a display or some other display element, which in particular may be an integral part of the functional component.

For the further building or construction of such a functional component, a display18is mounted to the rear side of cover body12, per the third mounting step shown inFIG.3c. Display18is mounted to the rear side of cover body12, for example, with the aid of an optical adhesive17. This third mounting step may be omitted when cover body12′, as shown inFIG.2b, already has a functional film51with one or more display elements.

Referring now toFIGS.4a,4b,4c, and4d, a decorative functional component in accordance with a second exemplary embodiment will be described.FIGS.4a,4b,4c, and4drespectively illustrate first, second, third, and fourth mounting steps for producing the decorative functional component in accordance with the second exemplary embodiment.

The decorative functional component in accordance with the second exemplary embodiment includes a plastic substrate21, a cover body22, and a transparent plastic layer24.

Plastic substrate21includes a recess23and is of a first plastic material. Plastic substrate21having recess23is manufactured by injection molding, per the first mounting step shown inFIG.4a. In addition, the inner edge of recess23here has a molded-on circumferential ridge26.

In the following second mounting step shown inFIG.4b, recess23in an injection mold is filled with a transparent second plastic material. After curing, the second plastic material forms a cover body22that fills up recess23. The second plastic material is chemically different from the first plastic material of plastic substrate21and is selected in such a way that the two plastic materials are not able to form an integrally bonded connection. As such, the two plastic materials cannot form a material bond with one another.

The overmolded circumferential ridge26thus forms a true form-fitting tongue and groove joint or connection29between plastic substrate21and cover body22, shown inFIGS.4b,4c, and4d, without their plastic materials forming a fixed connection to one another. A loose form-fit connection may thus be achieved in which cover body22is stable, but at the same time is seated within recess23of plastic substrate21with play and free of stress.

In the following third mounting step shown inFIG.4c, plastic substrate21and cover body22are flooded using a low viscosity liquid which subsequently cures to form transparent plastic layer24. Plastic layer24stabilizes the arrangement of cover body22on plastic substrate21. Consequently, cover body22, despite the loose, stress-free connection, can no longer be displaced or shifted relative to plastic substrate21. At the same time, plastic layer24optically conceals the multipart design of the surface underneath.

In the following fourth mounting step shown inFIG.4d, mounting a display28at the bottom side of cover body22by use of an optical adhesive27is optionally available.

Referring now toFIG.5, a decorative functional component in accordance with a third exemplary embodiment will be described. The decorative functional component in accordance with the third exemplary embodiment includes a plastic substrate31, a cover body32, and a transparent plastic layer (not shown inFIG.5).

The decorative functional component in accordance with the third exemplary embodiment is a variant of the decorative functional component in accordance with the first exemplary embodiment shown inFIGS.3a,3b, and3cin that plastic substrate31has a plane offset. In this regard, plastic substrate31at the edge of its recess (not numbered inFIG.5) forms a circumferential bent abutment ridge36. Clip hooks35of cover body32snap on to bent abutment ridge36. Bent abutment ridge36allows cover body32to be inserted into the recess of plastic substrate31in such a way that the surface of cover body32is in flush alignment with the surface of plastic substrate31.

As a result, the plastic coating (not shown inFIG.5) may have a very thin design compared to plastic layer14in the first exemplary embodiment, since in this case the plastic coating does not have to enclose a majority of the volume of cover body32.

FIGS.6aand6brespectively illustrate design details of a decorative functional component in accordance with one or more of the exemplary embodiments. Particularly,FIGS.6aand6bshow two examples of a possible design of the transition between a plastic substrate41and a cover body42.

For functional components, for example narrow straight gaps45may be provided between plastic substrate41and cover body42, as shown inFIG.6a. For functional components with rounded edges, gaps with transition radii46may be provided as shown inFIG.6b, which during the flooding operation are filled up by the low viscosity liquid. This low viscosity liquid after curing forms transparent plastic layer44.

LIST OF REFERENCE NUMERALS