FR2782162A1 - Pointer for instrument in vehicle dash board has finger molded onto cap covering and carried by hub, in simpler design reflecting incident light into pointer finger - Google Patents

Abstract

The pointer comprises a finger molded onto a cap which is carried on and covers, the front face of a hub. The hub includes reflective structures deflecting light received towards the finger.

Description

The present invention relates to the field of indicators to

  needle especially for dashboard of motor vehicles.

  The object of the present invention is to propose a new needle, of simplified structure compared to known prior needles. We know that most of the known needles are of very complex structure and typically include 1) an elongated index, 2) a barrel or hub designed to be fixed on a drive member, 3) a cap intended to cover the hub , 4) reflecting means

  placed opposite the hub, and 5) sometimes a counterweight.

  An example of embodiment of such a known needle will be found.

in document EP-A-0 295 165.

  The abovementioned object is achieved within the framework of the present invention by means of a needle which comprises an integral index for molding a cap, attached to a barrel or hub, the geometry of the cap being adapted to cover the front face of the barrel or hub and said barrel or hub being provided with reflecting structures for deflecting at least towards the index part of the light received from said barrel or hub. Other features, objects and advantages of the present invention

  will appear on reading the detailed description which follows, and

  look at the accompanying drawings, given by way of nonlimiting examples and in which: - Figure 1 shows a top view of a needle index in accordance with a preferred embodiment of the present invention, - Figure 2 shows a section view of this index according to the section plane referenced 11-11 in FIG. 1, - FIG. 3 represents a view from below of this index, - FIG. 4 represents a section view of this index according to the plane of section referenced IV-IV in Figure 2, - Figure 5 shows another sectional view of this index according to the section plane referenced VIII-VIII in Figure 2, - Figures 6 and 7 show two perspective views of the 'needle index, - Figures 8 and 9 show two perspective views of a needle hub according to the present invention, - Figure 10 shows a side view of this hub, - Figure 11 shows a view of above this hub, and - Figures 12 and 13 represent ntent two views in longitudinal section of this

  hub according to the section planes referenced respectively XII-XII and XIII-

XIII in Figures 13 and 11.

  There is shown in the accompanying figures, a needle for a dashboard indicator for motor vehicles, in accordance with

present invention.

  This needle 100 essentially comprises a barrel or hub by which the needle can be fixed on a drive means, and a tapered index finger 300 which extends in a general direction orthogonal to the axis

from canon 200.

  The drive means can be the subject of numerous embodiments. It may for example be a logometer or a stepping motor. Similarly, the means for connecting the barrel 200 to the output shaft of the drive means can be the subject of different embodiments. As can be seen in the appended figures, according to the preferred embodiment, the barrel 200 is provided with a channel 220 through which

  the needle can be driven onto the output shaft of the drive means.

  Furthermore, at least the index 300, is preferably made of an optically transparent material capable of forming an optical guide so that a light flux introduced into the needle, preferably at the level of the barrel 200 and for example deflected longitudinally in the index 300 by optical structures with prism effect provided at the level of the barrel 200,

  broadcasts from index 300 towards an observer.

  More precisely still according to the preferred embodiment illustrated in the appended figures, the needle 100 is formed by assembling two parts: a first part 200 forming a hub and intended to be fixed on a drive means and a second part formed by the combination of the index 300 and lateral protrusions 310 integral therewith and intended to form a cap covering the front surface of the

hub 200.

  The hub 200 and the second part 300/310 are each made of an optically transparent plastic material, to each form an optical guide structure. It is preferably polycarbonate or

polymethyl methacrylate.

  More precisely still according to the embodiment illustrated in FIGS. 1 to 7, the part 300/310 is essentially formed by a light bar or forefinger 300 and a rear heel 330 connected together by

  symmetrical lateral protrusions or flanges 310.

  The index 300 is tapered towards its end opposite to the heel 330. Thus its lateral flanks 301 converge away from this heel 330. Furthermore these flanks 301 can be defined by rectilinear generatrices parallel to the axis of rotation of the needle or generators which converge at least slightly, approaching the front surface 320 of the index finger

  300, that is to say the surface directed towards the user.

  This front surface 320 can be flat. However according to the embodiment illustrated in Figures 1 to 7 it is slightly curved, convex outward, either in a longitudinal plane as seen in Figure 2 for example, or in a transverse plane as shown seen in Figures 4 and 5. More specifically as seen in these Figures 4 and 5, preferably the index 300 is provided on its front face 320 with a longitudinal rib 302, having for example a cross section rounded in convex cylindrical sector, itself provided on its top with a longitudinal groove 303, for example of rectangular cross section

even slightly flared.

  The rear surface 304 of the index 300 is preferably slightly curved convex towards the outside and converges towards the front surface 320 away from the hub 200. Thus the rear surface 304 is adapted to return the light which travels towards the front surface 320 longitudinally in this index 300, coming from the hub 200, with an incidence at least substantially orthogonal to the axis of rotation, and this with a practically homogeneous luminosity over the entire length of the index 300. It will be noted that according to the mode of embodiment illustrated in Figures 1 to 7 attached, the lateral flanks 301 of the index are extended beyond the rear surface 304 in the form of partitions 305 of a few tenths of a mm over the entire length of the index 300. These partitions 305 are for example

visible in Figures 2, 4 and 5.

  Finally, it will be noted that the optical bar making up the index 300 is delimited on the hub side, by an entry surface 306, generally parallel to the axis of rotation and for example planar. This face 306 is called the "entry" surface, because it is through it that the light coming from the hub 200

enters index 300.

  Of course it is essential not to deposit a coating

  likely to obscure light, on this entry face 306.

  The heel 330 is also slightly tapered towards its end opposite the index 300. Thus its lateral flanks 331 converge away from this index 300. Furthermore, like the index 300, these flanks 331 can be defined by parallel rectilinear generatrices to the axis of rotation of the needle or of the generators which converge at least slightly, in proximity to the front surface of the needle, that is to say

  the surface directed towards the user.

  The front surface 336 of the heel 330 can be flat. However according to the embodiment illustrated in Figures 1 to 7 it is slightly curved, concave outward, in a longitudinal plane as seen in Figure 2 for example. This front surface 336 of the heel 330 is moreover preferably delimited by a plane generator orthogonal to

The axis of rotation.

  The rear surface 334 of the heel 330 converges towards the front surface 336 away from the hub 200. Thus the rear surface 334 is adapted to return to the front surface 336, the light which travels longitudinally in this heel 330, coming from the hub 200, with an incidence at least substantially orthogonal to the axis of rotation, and this with a practically uniform brightness over the entire length of the heel 330. According to the preferred embodiment illustrated in the appended figures, the rear surface 334 of the heel 330 is inclined compared to a

  plane orthogonal to the axis of rotation by an angle of around 240.

  Note that according to the embodiment illustrated in Figures 1 to 7 attached, the lateral flanks 331 of the index 330 and the rear edge thereof are extended beyond the rear surface 334 in the form of

  partitions 335 a few tenths of a mm around the entire periphery of the heel 330.

  These partitions 335 are for example visible in FIGS. 2, 4 and 6.

  Finally, it will be noted that the optical bar making up the heel 330 is delimited on the hub side, by an entry surface 338, generally parallel to the axis of rotation. This entry surface 338 can be flat. However, according to the embodiment illustrated in the appended figures, the surface 338 is preferably formed of a sector of cylinder of revolution around the axis of rotation of the needle. This face 338 is called the "entry" surface, because it is through it that the light coming from the hub 200

enters heel 330.

  Of course it is essential not to deposit a coating

  likely to obscure light, on this entry face 338.

  The protrusions 310 forming a cap can be the subject of

  many variants.

  According to the particular embodiment illustrated in the appended figures, these protuberances 310 define in combination a generally cylindrical structure of revolution. More precisely still according to the preferred embodiment illustrated in the appended figures, each of these protuberances 310 is defined by a front wall 312 of substantially semi-circular outline surrounded on its periphery by a skirt 314 substantially semi-cylindrical, convex towards the outside, in protrusion on its rear surface (alternatively the skirts 314 can be slightly

  frustoconical tapering towards the front of the needle).

  The front walls 312 meet in the middle part of the needle in the form of a longitudinal beam 316 which provides the connection between the bars 300 and 330 on the front of their respective entry faces 306 and 336. This beam 316 is itself provided on its front face, preferably, with a rounded rib having a longitudinal groove which extend the rib 302 and the groove 303 of the index 300. For the rest the front surface of the walls 312 is preferably generally planar

and orthogonal to the axis of rotation.

  The skirt sections 314, for their part, provide a connection between the

  partitions 305 and 335 which laterally border the index finger 300 and the heel 330.

  Preferably surfaces 338, 337, 303, 304, 320, 306 and 334

are polished optical surfaces.

  Of course as previously indicated in a variant, the

  contour of the skirts 314 may be non-cylindrical in revolution.

  We will now describe the structure of the hub 200 illustrated on the

Figures 8 to 13 attached.

  The hub 200 essentially comprises a barrel 230 pierced with a central through channel 220 and an upper shoulder 250 intended to be housed in the chamber 390 of the index finger and by which the hub 250 is fixed

in this room 390.

  The barrel 230 can be cylindrical of revolution around the axis of rotation of the needle. However as illustrated in the appended figures, preferably the barrel 230 is slightly frustoconical tapered towards its end

opposite index 300.

  The underside 232 of the barrel 230 is preferably flat and perpendicular to the axis of rotation. It preferably constitutes an entry face by which light is injected into the hub 230 with an incidence parallel to the axis of rotation, that is to say parallel to the axis of the channel 220. Preferably this face d input 232 is polished optically and adapted

  so as not to deflect the light received, when it is passed through.

  The light emitting means may be arranged directly opposite this input face 232. It may for example be light-emitting diodes. However as a variant, the light emitting means may be located at a distance from this entry face 232, the light being guided between these emitting means and said entry face 232 by any suitable means, for example guides formed by bars.

  molded optics of suitable geometry.

  According to yet another variant, the light emitting means can be adapted to direct a light flux towards the hub 200 with a radial incidence relative to the axis of rotation, the hub 200 then being provided at the barrel 230 with reflecting means with prism effect capable of returning parallel to this axis of rotation and towards the index 300 the light received from the emitting means with a radial incidence. Such prism reflector means on the barrel 230 can be inspired by the means defined in the patent application filed by the

  Applicant in France on June 16, 1998 under No. 98 07571.

  At the shoulder 250 there is provided on the one hand means adapted to ensure the fixing of the hub on the index 300, on the other hand reflective means adapted to deviate towards the index 300 and towards the heel 330 according to a direction generally orthogonal to the axis of rotation, the light

received parallel to this axis.

  The fixing means can be the subject of numerous modes of

production.

  According to the preferred embodiment illustrated in the appended figures, these fixing means comprise on the top of the shoulder 250, two plates in the form of crown sectors 252 whose upper surfaces are coplanar and intended to come to rest against the lower surface walls 312 of the index cap to be

attached to them.

  To this end, the external radius of the plates 252 is substantially equal,

  while being slightly lower than that of the walls 312.

  More precisely still, the plates 252 are preferably fixed to the walls 312 by ultrasonic welding. To this end preferably, the plates 252 are each provided with several ribs 254, for example of triangular cross section, ensuring contact between the plates 252 and the

  walls 312 and the connection zone between them.

  According to the nonlimiting embodiment illustrated in the appended figures, each plate 252 is thus provided with three ribs 254

  equally spaced and generally radial to the axis of rotation.

  The plates 252 are substantially diametrically opposite with respect to the axis of rotation. The reflective means provided at the shoulder 250 are

disposed between these plates 252.

  There is thus provided a structure 260 intended to divert part of the flow towards the index 300 and a diametrically opposite structure 270 intended

  to divert another part of the flow to the heel 330.

  The structure 260 consists essentially of a bar 262 generally radial with respect to the axis of rotation which has a radially internal surface 264 inclined on the order of 45 relative to this axis of rotation, diverging with respect to this axis approaching the top of the hub 200. The function of this surface is to deflect received from the base of the hub 200 with an incidence substantially parallel to the axis of rotation, in a radial direction towards the outside, inside the bar 262. This surface 264 is preferably delimited by rectilinear generatines inclined by about 45 relative to the axis of rotation as indicated above. The surface 264 can be flat or slightly inclined convex towards the outside, as illustrated in the appended figures. The exit surface 266 of the bar 262 is intended to be placed opposite the entry surface 306 of the index 300. This exit surface 266 is preferably adapted so as not to deflect the light. Thus this surface 266 is preferably flat and orthogonal to a radius erected at

from the axis of rotation.

  It will be noted that the bar 262 projects widely from the outside of the

was 230.

  On the other hand, the structure 270 associated with the heel 330 consists essentially of a bar 272 generally radial relative to the axis of rotation which is contained in the casing of the barrel 230. This bar 272 has a radially internal surface 274 inclined by about 45 with respect to this axis of rotation, diverging from this axis in approach to the top of the hub 200. The function of this surface 274 is to deflect the light received from the base of the hub 200 with an incidence substantially parallel to the axis of rotation, in a radial direction towards the outside, inside the bar 272. This surface 274 is preferably delimited by rectilinear inclined generatrices

  about 45 with respect to the axis of rotation as indicated above.

  The surface 274 can be flat or slightly inclined convex towards

  the exterior, as illustrated in the appended figures.

  The outlet surface 276 of the bar 272 is intended to be placed opposite the inlet surface 338 of the heel 330. This outlet surface 276 is preferably cylindrical of revolution around the axis of rotation and

  complementary to the entry surface 338 of the heel 330.

  The path of the light according to the preferred embodiment of the present invention is as follows: the light is introduced into the barrel 230 of the hub 200, by the input face 232, with an incidence parallel to the axis of the hub 200 , the light is guided in the barrel 230 until it reaches the deflection faces 264 and 274, 20. the face 264 deflects part of the light radially outwards, and this part of the light after passing through the faces of output 266 and input 306 propagates in index 300; at this level it is deflected by the rear surface 304 of the index 300 towards the front face of the needle, the face 274 deflects another part of the light radially outwards and this part of the light after having crossed the exit faces 276 and entry 338, propagates in the heel 330; at this level it is deflected by

  the rear surface 334 of the heel 330 in the direction of the front face of the needle.

  Again preferably the surfaces 264, 266, 274 and 276 are

polished optics.

  The integration of the cap 310 by molding on the index 300 makes it possible in particular to avoid any leakage of light between this cap 310 and the index 300 as was the case with the known prior solutions in which generally the cap is formed of a piece initially

  separated from the index and reported thereon.

  Of course the present invention is not limited to the particular embodiments which have just been described but extends to all variants in accordance with its spirit. Thus according to an alternative embodiment of the present invention, the needle comprises at least one part (preferably formed by the index 300 and the cap 310) provided with a coating (if necessary constituted by a succession of multiple layers ) having a controlled area at which said coating is at least partially removed. By way of nonlimiting example, this zone can be defined by the longitudinal bottom surface of the groove 303 and a contour in the form of

  "brush" referenced 337, on the front surface of the heel.

Claims (16)

  1. Needle for an indicator, in particular for a dashboard of a motor vehicle, characterized in that it comprises an index (300) integral with the molding of a cap, attached to a barrel or hub (200), the geometry of the cap being adapted to cover the front face of the barrel or hub (200) and said barrel or hub (200) being provided with reflecting structures for deflecting at least towards the index part of the   light received from said barrel or hub (200).   2. Needle according to claim 1, characterized in that the barrel (200) is driven into a blind cavity (390) opening onto the   rear surface (395) of the index finger (300).   3. Needle according to one of claims 1 to 2, characterized by   causes the barrel or hub (200) to be fixed to the index finger by ultrasonic welding.   4. Needle according to one of claims 1 to 3, characterized by the   one of the barrel (200) or the index (300) is provided with projecting structures (254) to ensure contact between the barrel (200) and the index (300) and   an ultrasonic weld between them.   5. Needle according to one of claims 1 to 4, characterized by the   causes the cap to be formed from lateral protrusions (310) integral with the index (300).   6. Needle according to claim 5, characterized in that the   protuberances (310) are formed between an index finger (300) and a heel (330).   7. Needle according to one of claims 1 to 6, characterized by the   fact that the index (300) is provided on its front face (320) with a longitudinal rib (302), having for example a rounded cross section in a convex cylindrical sector, itself provided on its top with a longitudinal groove ( 303), for example of rectangular cross section even slightly flared.   8. Needle according to one of claims 1 to 7, characterized by the   fact that the index (300) is made of polymethylmethacrylate or polycarbonate.   9. Needle according to one of claims I to 8, characterized by the   fact that the needle barrel (200) has reflecting structures (260, 270) with prism effect capable of returning longitudinally in the index (300)   a luminous flux received in the barrel.   10. Needle according to one of claims 1 to 9, characterized by the   causes the underside (232) of the barrel (200) to be flat and perpendicular to the axis of this cannon.   11. Needle according to one of claims 1 to 10, characterized by   the fact that it is associated with light emitting means suitable for directing a light flux towards the hub (200) with a radial incidence relative to the axis of rotation, the hub (200) being provided with reflecting effect of prism capable of returning parallel to this axis of rotation and towards the index (300) the light received from the emitting means with a radial incidence.   12. Needle according to one of claims 1 to 11, characterized by   the fact that the barrel (200) has a structure (260) adapted to deflect   at least part of the luminous flux towards the index (300).   13. Needle according to one of claims 1 to 12, characterized by   the fact that the barrel (200) has a structure (270) adapted to deflect   at least part of the light flux towards a heel (330).   14. Needle according to claim 12, characterized in that this structure (260) consists essentially of a bar (262) generally radial relative to the axis of rotation, which has a radially internal surface (264) inclined about 45 relative to this axis of rotation, diverging from this axis in approaching the top of the hub (200), to deflect the light received from the base of the hub (200) with a substantially parallel incidence at the axis of rotation, in a radial direction towards the outside, inside the bar (262), the exit surface (266) of the bar (262) intended to be placed opposite the entry surface (306) of the index (300) being preferably adapted so as not to deflect the light, this exit surface (266) being planar and   orthogonal to a radius erected from the axis of rotation.   15. Needle according to claimn 13, characterized in that this structure (270) consists essentially of a bar (272) generally radial relative to the axis of rotation and which has a radially internal surface (274) inclined about 45 relative to this axis of rotation, diverging from this axis in approaching the top of the hub (200), to deflect the light received from the base of the hub (200) with a substantially parallel incidence to the axis of rotation, in a radial direction towards the outside, inside the bar (272), the exit surface (276) of the bar (272) intended to be placed opposite the entry surface (338) of a heel (330) being preferably cylindrical of revolution around the axis of rotation and complementary to the   entry surface (338) of the heel (330).   16. Indicator for a dashboard of a motor vehicle, characterized in that it comprises a needle conforming to one of the claims 1 to 15.