Abstract:
An instrument panel having at least one needle indicator comprising a dial of indicating characters supported by a first faceplate, an indicating needle and a motor for rotating the needle along the dial. The instrument panel includes a second faceplate for supporting other indicating characters, such that the indicating needle is configured to lie between the two faceplates. The faceplates are screen-printed flat before being shaped in relief.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present Application claims the benefit of priority to the following International Application: PCT Patent Application No. PCT/FR2005/001959 titled “Instrument panel having two faceplates and method of forming a faceplate for the instrument panel” filed on Jul. 27, 2005 (which is incorporated by reference in its entirety). 
     FIELD 
     The application relates to an instrument panel with at least one indicator having a dial supported by a faceplate, especially for a motor vehicle or any other means of locomotion. 
     BACKGROUND 
     A motor vehicle instrument panel generally comprises a number of indicators, for example a speedometer, an engine revolution counter, a fuel level indicator, and especially needle indicators. 
     The needle of an indicator, controlled and rotated by a motor, or movement, generally extends in front of a support bearing screen-printed indicator characters forming a dial (for example graduations and values). The indicator is thus mounted in a protective and screening hood, which supports a protective window. 
     The support for the screen-printed indicating characters bears the name “faceplate”. It generally comprises a thick sheet of opaque or translucent plastic. 
     The Applicant has sought to provide a novel instrument panel offering many options in the arrangement of the indicating characters, especially the arrangement of the graduations with respect to the values denoting them, in rendering relief effects and in playing with transparency and opacity effects. 
     The related art only provides devices in which there are fewer options, these being limited to specific relief effects. Thus, for example, devices are known which have an indicating needle, rotated in front of a screen-printed faceplate formed in relief, which have a needle rotated to the rear of a flat faceplate, and which have a needle rotated at the front of a faceplate, with a protective window placed to the front and itself also having indicating characters. The alternatives offered to the designer of an indicator can therefore be summarized as giving a relief effect to a faceplate, playing with the arrangement of the faceplate with respect to the needle, or giving a protective window the function of a front window. These alternatives have limited application. 
     SUMMARY 
     The embodiments disclosed in this application relate to an instrument panel having at least one needle indicator comprising a dial of indicating characters supported by a faceplate, an indicating needle and a motor for rotating the needle along the dial, characterized in that it includes a second faceplate for supporting other indicating characters, the needle lying between the two faceplates. 
     In this case, indicating characters may be provided on both faceplates of the indicator, each individually providing potentialities inherent to their nature. This offers many options of attractive visual effects. In this regard, the instrument panel may even by referred to as a “universal” instrument panel. 
     Preferably, at least one of the two faceplates has structures in relief. Advantageously in this case, said faceplate having structures in relief is produced by screen printing flat, before being shaped in relief. 
     Again preferably, the dial is formed by a combination of indicating characters on said faceplate and said other indicating characters on said second faceplate. 
     Advantageously, the instrument panel includes illumination means located to the rear of the two faceplates. 
     Again advantageously, the second faceplate fulfils the function of a protective window. 
     The invention also relates to a method of forming a faceplate for the instrument panel presented above, in which instrument panel a faceplate is formed from a sheet of polycarbonate with a thickness between 0.3 and 0.5 mm, said method being characterized in that the faceplate is screen-printed flat and then shaped in relief, by cold forming or hot forming. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The invention will be more clearly understood from the following description of two embodiments of the instrument panel according to the invention, with reference to the appended drawing in which: 
         FIG. 1  shows a sectional view of a first embodiment of the instrument panel according to the invention; and 
         FIG. 2  shows a sectional view of a second embodiment of the instrument panel according to the invention. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , an instrument panel includes two indicators  1  and  12 , the indicator  1  having a needle  2  rotated by a motor (not shown) via a spindle hub  3 . 
     The needle  2  extends in front of a first faceplate  4 , that portion of said faceplate  4  which is associated with the indicator  1  being plane. This first faceplate  4  here is partially translucent. It includes indicating characters  5  screen-printed on its front surface. Here, these are graduations  5  of a counting scale for the dial of the indicator  1 . 
     Extending to the front of the first faceplate  4  and of the needle  2  is a second faceplate  6 , which is also partially translucent. It is formed so as to extend in relief, in order to give the indicator  1  a particular visual effect. In this case, the second faceplate  6  is formed, in its portion associated with the indicator  1 , so as to create an envelope in the form of a dome  7  to the front of the needle  2 . A cylindrical wall  8  extends towards the rear from the annular edge of the dome  7  as far as the point where it contacts the front of the first faceplate  4 , after which a wall  9  of frustoconical shape extends towards the front, said wall  9  bearing indicating characters, here screen-printed numerals  10 , which give values to the graduations  5  that are located within the chamber of the dome  7  and form, in combination with said graduations, the dial of the indicator  1 , the needle  2  of which indicates the values. 
     Here, both faceplates  4 ,  6  are back-lit, for example by light-emitting diodes (not shown), in a manner well known to those skilled in the art. The screen printing forming the graduations  5  and the numerals  10  may here be either opaque, so that the indicating characters appear as Chinese shadows, or translucent, with a different colour from the outline of the characters, so that they appear transparent, or they may be a combination of the two. 
     The second indicator  12 , similar to the first, also comprises a needle  13 , which here is a dome-shaped needle, an extension  14  of the first faceplate  4 , located to the rear of the needle  13 , and an extension  15  of the second faceplate  6 , located to the front of the needle  13 . The extension  14  of the first faceplate  4  is formed as a cup for housing the needle  13 , the extension  15  of the second faceplate  6  being plane. The two indicators  1 ,  12  may be lit by the same illumination means. 
     In the preferred embodiment of the instrument panel, each of the faceplates  4 ,  6  is made of a relatively thin sheet of polycarbonate, in this case with a thickness between 0.3 and 0.5 mm. Such a sheet of polycarbonate is relatively flexible. The sheet is screen-printed flat, that is to say it lies in a plane and that the indicating characters  5 ,  10  are screen-printed thereon. Once the sheet has been screen-printed, it is shaped in relief. This forming operation may take place either cold or hot, constituting a thermoforming operation in the latter case. Cold forming is conceivable owing to the thinness of the sheet. One advantage of such a method of forming the faceplates  4 ,  6  is its low cost, since screen printing flat is much simpler than screen printing in relief. Consequently, the designer is completely free to give the faceplates  4 ,  6  any aesthetically or functionally useful shape in relief, on the one hand because the screen printing has already been applied and, on the other hand, because the thinness of the sheet gives it great forming flexibility. 
     In addition, it is possible, by giving a polycarbonate sheet an appropriate shape, to stiffen it. This thus applies, for example, to a polycarbonate sheet which is made in the form of a dome, as is the case here for the second faceplate  6  of the first indicator  1 . Thus stiffened, the faceplate  6  can fulfil the function of a protective window, which is to protect the indicator, and especially the needle, from the outside. For this purpose, said front face  6  may additionally be treated with an anti-reflection coating. This therefore appears to be another advantage of the instrument panel. The faceplate function is not given to a protective window by screen-printing it, but, since the shape of such a protective window is simple, rigid and non-modifiable, the function of a protective window is given here to a faceplate, said protective window also having all the advantages of a faceplate, whatever its capability of being formed in relief or the possibility of screen-printing it in various colours, at the point where the indicating characters are or away from them. 
     It goes without saying that the protective window function of the faceplate  6  could be obtained more simply, that is to say without defining a shape whose constraints dictate the stiffness of the sheet, by using a thicker polycarbonate sheet than that used in the embodiment that has just been described. The thickness of the sheet then ensures its stiffness and therefore its function. 
       FIG. 2  shows a second embodiment of the instrument panel according to the invention. 
     A first indicator  20  here has a needle  21 , rotated by a motor via a spindle hub  22 , which extends in front of a partially translucent first faceplate  23 . This first faceplate  23  has a plane circular back wall  24 , extending beneath the needle  21 , a frustoconical wall  25  extending forwards from the edge of back wall  24 , said wall  25  having indicating characters, here graduations  26  of a counting scale forming the dial of the indicator. Extending from the front edge of this frustoconical wall  25  is a plane wall portion  27  parallel to the back wall  24 . 
     A partially translucent second faceplate  28  extends in front of the first faceplate  23  and the needle  21 . This second faceplate  28  is plane and lies just in front of the plane wall portion  27  of the first faceplate  23 . On its internal surface, it has indicating characters and numerals  29 , forming, with the graduations, the dial of the indicator  20 . It also includes a circular mask  30 , screen-printed in line with the spindle hub of the needle  21  and concealing the central part of the needle  21 . 
     In the same way as previously, the indicator  20  is back-lit. The appearance of the indicating characters is as described above. 
     The instrument panel shown in  FIG. 2  includes a second indicator  31 , identical to the first indicator  20 , formed from the same faceplates  23 ,  28  and back-lit with the first indicator. 
     The faceplates  23 ,  28  are formed using the same method as that described above, namely screen printing flat followed by forming in relief, in respect of that face having structures in relief. 
     The instrument panel furthermore includes here a protective window  32 , which lies to the front of the two indicators  20 ,  31 . The two faceplates  23 ,  28  therefore fulfil here only a faceplate function. The advantage of this embodiment is the complete freedom for the designer to arrange the faceplates  23 ,  28  to his taste, without shape constraints linked with the stiffness of the sheet, the protection function being independently fulfilled by the protective window. 
     Thanks to the invention, many options in the way the dial of an indicator appears are offered to a designer, who can easily design the forming of the two faceplates so as to give them relief effects, independently of each other or linked to each other, the arrangement of the screen-printed indicating characters, on one and the same faceplate or, relative to one another, on both faceplates, especially graduations in relation to numerals demoting them, and also the arrangement of other indications or features, such as concealments, abbreviations, etc. 
     The universal nature of the indicator according to the invention clearly stems from studying the many advantages, whether correlated or uncorrelated, that have been raised. 
     The invention has only been described in relation to back-lighting, but front lighting could be added, for example with phosphorescent indicating characters. 
     In addition, the screen-printed markings may be applied on one side of the faceplates or on the other, which may also be in different colours, at least in some of their portions. 
     Furthermore, physical features other than screen-printed features may be added to the faceplates. For example, the faceplate lying in front of the needle may include a solid cover for concealing the central part of the needle, or on the contrary a recess allowing it to project from its surface. 
     Both the faceplates described are translucent. However, that one located to the rear of the needles could be opaque while that one located to the front could be translucent, the lighting then being provided either to the front of the faceplates or between them. 
     It goes without saying that more than two faceplates may be provided.