FR2778453A1 - Reflector for motor vehicle headlamps - Google Patents

Abstract

The reflector has two surfaces (1,2) generated as surfaces of revolution using a spiral logarithmic generator. The two surfaces may be coaxial or have offset axes, and may be co-linear or separated by a horizontal plane (3). The two surfaces may also be formed as four separate surfaces of revolution, each generated from a logarithmic spiral. A hole is provided in the middle for the lamp (4).

Description

[The present invention relates to a reflector for

vehicle lights.

  The invention relates to a reflector which can be used to produce a low beam, an anti-fog light or even a low beam combined with

a high beam.

  Known reflectors are generally formed of a parabolic surface whose development is complex and in which the position of the light source is

very important.

  The object of the present invention is to produce a reflector whose focusing is simpler and

  whose position of the light source is less constrained

  annoying. The reflector according to the invention is of the type

  with cut-off, i.e. in the case of the dipped beam

  or anti-fog lights, the lighting does not exceed

  not a certain height determined by regulations.

  The reflector, object of the invention, uses the fluid optics technique described in French Patent No. 2,689,961. Thus, it is possible to carry out

  a low beam or a fog light and more generally

  Also all fires requiring shutdown in one way

  simpler than in the prior art.

  Vehicle light cut-off reflector

  is of the type in which a lamp is housed and is characterized

  laughed at in that it includes, at least, two surfaces of

  logarithmic spiral generator revolution.

  The two surfaces of revolution with a spiral generator can be coaxial, offset or co-linear.

  According to another characteristic of detail, the two surfaces are separated by a horizontal plane. If you want the illumination to extend above a cut line, for example, to better illuminate the side of the road, the two surfaces can

  be separated by two intersecting half-planes.

  According to yet another constructive detail, the

  two surfaces are separated by shoulders.

  According to an alternative embodiment, each of the two surfaces is divided in two so as to present

  four surfaces of revolution with spiral generator loga-

  rithmic. Such a variant is particularly suitable for producing an optic intended for a main beam and for a dipped beam, the lamp used being a lamp with two filaments, one of which, intended for the dipped beam, is masked by a cup, cache or

screen.

  According to a detail characteristic of this variant, the four surfaces are separated by two perpendicular planes. According to yet another constructive detail, the

four surfaces are coaxial.

  Finally, the four surfaces are separated between

them by edges.

  The invention will now be described in more detail with reference to embodiments

  individuals given by way of example only and represented

  ted to the accompanying drawings, in which:

  Figure 1 is a perspective view of a reflective

cut off according to the invention.

  Figure 2 and Figure 3 are schematic views showing the operation of the reflector of Figure 1. Figure 4 is a perspective view of a

  alternative embodiment of the reflector according to the invention.

  Figure 5 schematic image of operation

  of the reflector of Figure 4 in the low beam position

  is lying. Figure 6 schematic image of operation

  of the reflector in the high beam position.

  In the embodiment of Figure 1, the reflector is divided into two surfaces 1 and 2 along a horizontal plane, a shoulder 3 being formed between these two surfaces. An opening 4 is provided for the passage of a lamp which can be of any type,

  with discharge or with an incandescent filament.

  Each surface 1 and 2 forms a half-reflector

  with surface of revolution with logarithmi spiral generator

than.

  The schematic views of Figures 2 and 3 allow-

  try to better understand the functioning of the reflector which, in this embodiment, can be used either

  for a low beam, or for a fog light.

  To facilitate understanding, the reflector has been divided into four zones 1, la, 2, 2a on the understanding that zones 1 and la are symmetrical to one another

as well as zones 2 and 2a.

  Reference 5 corresponds to the horizontal line

  located 25 meters from the reflector and whose height must not be exceeded in accordance with regulations.

  Reference 6 designates an assumed target in order to better understand the distribution of the different

  light flux and reference 7 the optical axis of the reflec-

  tor. As can be seen in FIGS. 2 and 3, the flux coming from zone 1 illuminates part 6a of the

  target 5, while the flux coming from zone 2 illuminates part 6b of target 6.

  The flow from zone 1a (see FIG. 3) lights up part 6b of target 6, while the flow returned by zone 2a lights up zone 6a. So the

  different flows intersect to illuminate a defined area

  tee. In this embodiment, it has been assumed that the two surfaces 1 and 2 are separated by a horizontal plane but, depending on the beam to be obtained, provision may be made for the surfaces 1 and 2 to be separated by a horizontal plane, while the surfaces 1a and 2a are separated by an inclined plane or vice versa, depending on whether it is a right or left headlight so that the beam s which illuminates the road does not exceed a determined height,

  but that, on the other hand, the part of the beam which is intended to illuminate the low side can illuminate the latter at a higher height.

  In this embodiment, the two surfaces 1 and 2 which are of revolution with logarithmic spiral generator are coaxial but they can, depending on the

  beam configuration to be obtained, be offset or 10 co-linear.

  In Figure 4, there is shown an alternative embodiment of the reflector, according to the invention, intended to be used in an optic ensuring the functions

main beam and low beam.

  In this embodiment, a lamp having two filaments is used, one of the corresponding filaments.

  laying in the low beam being masked by a cup20 or any other form of screen. In the embodiment of Figure 4, the cup is arranged vertically.

  The reflector comprises four surfaces 12,

  13, 14 and 15 each formed by a surface of revolution.

  logarithmic spiral generator.

  The surfaces 12 and 14 are separated by a shoulder 17 and the surfaces 13 and 15 by a shoulder 18. A hole 19 is provided for the passage of the lamp and the surfaces 12 and 13 are separated by a sharp edge 20, while the surfaces 14 and 15 are delimited by a shoulder 21.35 In the low beam configuration, if it is assumed that the cup is located on the right side, the

  with the lamp viewed from the front, only surfaces 12 and 14 are used (see Figure 5).

  s The reference 23 designates the optical axis of the reflector and the reference 24 a target assumed to better show the distribution of the light fluxes. As shown in FIG. 5, the flux coming from the surface 12 illuminates the lower part 24a of the target, while the flux emanating from the surface 14 illuminates the lower part 24b of said target. The two flows remain below the horizontal line 25, the height of which must not

to be exceeded.

  In the high beam configuration, the surface 12 returns the flux towards the center above the horizontal line 25 in an area 27, while the surface 14 returns an eccentric flux offset radially with respect to the part 24b of the target 24, in a zone 28. The surface 13 which is opposite the surface 14 returns the flux to a zone 30 situated on the side of the part 24a of the target below the line 25, a small part of the flux coming from locate above the

  line 25 in the central part 31.

  Finally, the surface 15 returns a flow which comes

  fill a zone 29 located on the side of part 24b of the target between zones 28 and 30.

  In all the cases described here, the four surfaces are of revolution and coaxial.

  Of course, the invention is not limited to the embodiments which have just been described and

  represented. Many modifications can be made

  details without going beyond the scope of the invention

tion.

Claims (11)

R E V E N D I C A T IONS   1. Vehicle cut-off light reflector in which a lamp is placed, characterized in that it comprises, at least, two surfaces (1 and 2) of revolution   with logarithmic spiral generator.   2. Cut-off vehicle fire reflector according to claim 1, characterized in that the surfaces (1, 2) are coaxial.   3. Cut-off vehicle fire reflector according to claim 1, characterized in that the surfaces (1, 2) are offset.   4. Cut-off vehicle fire reflector according to claim 1, characterized in that the surfaces (1, 2) are co-linear.   5. Cut-off vehicle fire reflector according to claim 1, characterized in that the two   surfaces (1, 2) are separated by a horizontal plane.   6. Cut-off vehicle fire reflector according to claim 1, characterized in that the two   surfaces (1, 2) are separated by two intersecting half-planes.   7. Cut-off vehicle fire reflector according to claim 1, characterized in that the two   surfaces (1, 2) are separated by shoulders (3).   8. Cut-off vehicle fire reflector according to claim 1, characterized in that each   of the two surfaces is divided in two, so as to present   ter four surfaces 12, 13, 14, 15 of revolution to generally logarithmic spiral trice.   9. Cut-off vehicle fire reflector according to claim 8, characterized in that the four surfaces (12, 13, 14, 15) are separated by two perpendicular planes. Es 10. Cut-off vehicle fire reflector,   according to claims 8 and 9, characterized in that the four surfaces are coaxial.   11. Cut-off vehicle fire reflector,   according to claims 8 and 9, characterized in that   the four surfaces are separated from each other by edges (20).