GB2033069A - Improvements in or relating to vehicle headlamps - Google Patents

Abstract

In an optical system, especially for car headlamps, comprising a glass or face member 6 connected to the periphery of a reflector member 1, one of said members contains a peripheral groove 2 inside of which is seated the peripheral edge 5 of the other said member. The side 4 of the groove has an inwardly- directed lip 10 to engage with a projection 11 on the edge 5, the reflector and, if desired, the member 6 being semi-resilient. The groove may contain material 7 such as glue, plaster or rubber. <IMAGE>

Description

SPECIFICATION Improvements in or relating to-vehicle headlamps This invention concerns optical systems, especially for vehicle headlamps.

Up to the present, the transparent faces or glasses of vehicle headlamps have been connected to the reflectors so as to constitute an optical system, by mechanical means such as screws, rivets, clamps, hooks or clips, which are intended also to ensure the centering, as well as the tightness of the two parts with respect to one another.

However, in many cases this centering and tightness are only relative and in addition, the fastening means used hitherto, project on the outside of the optical system, which increases its overall dimensions and also necessitates the introduction of a mask or covering.

The invention seeks to remove these disadvantages and for this purpose provides an optical system in particular for car headlamps, comprising a glass or face member connected to the periphery of a reflector member, in which optical system one of said members contains a peripheral groove inside of which can be placed the peripheral edge of the other said member.

If desired, a connecting material such as an adhesive or a binder may be placed in the bottom of the groove.

The peripheral edge of the part to be placed in the groove may conveniently form a flange and one of the sides of the groove may have a lip directed towards the inside of said groove.

According to a further feature of the invention, the peripheral flange of one of the members forms a lateral projection which is perpendicular to the lip directed towards the inside of the groove, the said projection and lip constituting a ratchet hook mechanism.

The invention thus enables the production of an optical system which is simple and inexpensive in construction and which enables a quick and strong connection to be made between the glass and the reflector of which it consists, without the need for any metal or other detachable mechanical part to achieve the required connection.

The optical system provided by the invention automatically ensures the optical centering both in the lateral and in the axial direction of the two members with respect to one another and enables a good tightness to be obtained without the means for achieving the connection and the tightness projecting inside or outside of the peripheral connecting edges, this connection also being either detachable or permanent.

The invention will be described further, by way of example with reference to the accompanying drawings, in which: Figure 1 is a section of part of an optical system taken at the level where the glass and the reflector are connected, Figures 2 and 3 are fragmentary sections relating to alternative connections, Figure 4 is a section similar to that of Fig. 1 of another optical system embodying the invention, Figure 5 is a developed perspective view of the groove in the reflector of Fig. 4, Figure 6 is a section taken on the line A-A of Fig. 5, and Figure 7 is a section taken on the line B-B of Fig. 5.

In the embodiment shown in Fig. 1, the reflector 1, which is metallised on its inner side 1,, is provided on its peripheral edge with a groove 2 defined by the sides 3 and 4.

This groove 2 is intended to receive a peripheral edge or lip 5, made in the form of a flange, of the transparent face 6 provided on the inner side 6, of the optical system giving the desired shape to the luminous beam issuing from the lamp (not shown) by the reflector 1.

It will be seen from this embodiment that the optical centering of the face 6 is automatically obtained with respect to the reflector 1 by proportioning the width of the flange 5 with relation to the width of the groove 2, the centering tolerance corresponding to the lateral, on the whole relatively small, play existing between the flange and the groove.

In addition, this centering if desired could be ensured by making the groove 2 of greater width than that of the flange 5, the flange in this case being made so that, on fitting, its inner side or its outer side respectively is supported against the sides 3 or 4 of the groove 2.

The positioning of the reflector with respect to the glass or face being thus obtained, various means may be used for making the connection of these two members either permanent or detachable, but in all cases connection means are placed within the thickness of the groove and no part of them projects inside or outside of the optical system.

Thus, as shown in Fig. 1, the connection of the face and the reflector is obtained by means of a binder 7 such as glue, a cement or plaster, an elastomer or polyurethane or rubber placed in the bottom of the groove 2 before the assembly, a slot or notch 8 being in this case preferably made in the edge of the flange 5 so as to form a peripheral cavity for receiving any excess binder resulting from irregular deposition thereof in the bottom of the groove 2. The notch 8 constitutes an overflow space which prevents the binder from overflowing from the groove 2 during the connection, especially into the inside of the reflector.

The notch 8 also provides a means for accommodating the effects of rough edges or burrs which form in this part of the face during its grinding, which edges when coming up against the bottom of the groove 2 would cause defective positioning of the face with respect to the reflector.

The bottom of the groove 2 or the peripheral edge of the face 6 may also be provided with pressed, stamped or ground studs 9, of which the exact height altows the two members to be strictly positioned with respect to one another, in the axial sense, irrespective of any surface irregularities or rough edges or burrs which may exist.

It may be noted that the binder 7 ensuring the connection of the two parts is desirably slightly elastic in order to accommodate differential expansion of the face and the reflector without interferring with the firmness of the connection.

As shown in Fig. 1, one of the sides of the groove has an inwardly directed flange or lip 10 which extends perpendicularly to a projection or ledge 11 so as to provide a ratchet-like means for prepositioning of the face with respect to the reflector.

The flange 10 and the ledge 11 respec tively have sides 1 t and 111 which are approximately perpendicular to the direction of the join of the two parts so as to constitute a hook for securely retaining the face on the reflector.

The interengagement of the two members in this embodiment is facilitated by making the reflector 1 and if desired, the face 6, of semi-rigid material of a nature such that, taking into account the depth of the ratchetlike pre-positioning means, the side 4 of the groove or the edge of the face 6 may be deformed during the introductio, of the flange 5 of the face into the groove.

As may be seen from Fig. 1, the ledge 11 is made so that a degree of play exists between the hooked edges 1 1 and 111. In this way, the flange 10 and ledge 11 constitute the means which ensure the prepositioning of the face with respect to the reflector and also act to conceal any possible overflow of the binder.

However, the ledge 11 could alternativety be made in such a way that, taking account of the height of the studs 9, the edge 111 is applied without play against the edge 101 of the flange 10, so as to define a hooked arrangement for determining the permanent position of the two parts with respect to one another. In this case, if desired, the binder 7 could be replaced by a compressible joint incorporating a seal or gasket.

The reflector 1, provided with the groove 2, may also be made of a heat-mouldable material, the properties of which may be used to make the mechanical connection after the face 6 has been positioned in the groove.

Thus, in the example shown in Fig. 2, the right-hand edge of the side 4 of the groove has its free end 41 pressed down by a heatmoulding operation on to the flange 5 of tho face 6, forming a detent such as permanenlly to imprison the flange and to position the face member with respect to the reflector.

The flange 5 of the face member may be of any shape, either angular, as shown in Fig. 1, or circular or hyperbolic, as shown in Figs. 2 or 3.

In the two last cases, the extreme edge of the flange 5 comes into contact with the bottom of the groove 2 along a line, thus enabling a line contact to be established by virtue of which the face member and the reflector member may be exactly positioned in an axial direction without necessitating the presence of studs 9.

In Figs. 4 to 7, there is illustrated a reflector 1 which receives in the outer groove 2, the edge 62 of a face member 6 provided, on its inside face, with the aforementioned optical system 6, giving the desired shape to the luminous beam issuing from the bulb or bulbs mounted on the reflector 1.

In order to permit the connection of the face member 6 to the reflector 1, the lateral edges of the face member and the groove 2 are provided with complementary hooks by which a ratchet-like connection is established.

In the example shown, the face member 6 is provided with extensions 63 which are distributed symmetrically or dissymetrically, these extensions being provided with hooks 12 complementary to hollow zones 13 formed in the outer wall or side 4 of the groove 2.

Each hollow zone 1 3 is provided with a membrane 14 produced by a grinding operation during the manufacture of the reflector 1, the membrane 14 being so situated in the hollow zone 1 3 that it may be at least deformed, or else broken by the complementary hook 12 of the face 6.

The upper edge 12, of the hook 12 then rests on the upper edge 13, of the hollow zone 13, either directly, or indirectly by the intermediary of the upper edge 14, of the membrane 14.

This arrangement enables the manufacture of the reflector to be simplified while still permitting the reflector and the face member to be assembled by a ratchet-like connection and creating a groove 2 which is closed so as to prevent the liquid or viscous binder 7 running out.

In fact, it will be observed that the part of the hook 1 2 which penetrates into the hollow zone 13, after having broken the membrane 14, forms a plug or stopper for the broken part thereof and then prevents the binder 7 from running out through the resulting lateral orifice.

As shown in the drawings, the hollow zon 1 3 provided with its membrane 14 is made in a projection 15 directed towards the interior of the groove 2, this projection having an upper edge 15, which is inclined so as to facilitate the introduction of the edge of the face member into the groove by using the inherent elasticity of the material comprising the reflector 1.

In this embodiment, the groove 2 is of a width greater than the thickness of the face member 6, but the thickness of the projection 1 5 is such that, taking into account the thickness of the face member, the inner or outer sides of the latter rest against the edge of the inner wall or side 3 of the groove 2, on the inside edge of the projection 15, thereby constituting a means for lateral positioning of the face member 6.

The lateral walls 152 and 1 53 of the projection 1 5 are also of small thickness (see especially Figs. 3 and 4), the projection 15 itself being formed at the base of a seating 1 6 by deformation of the lower wall of the groove 2.

This arrangement allows the extensions 63 of the face member 6 to be made of a relatively great height with consequential good stability, the height of the extensions 63 also being such that the lower end comes to rest against the bottom of the groove 2 when the edge 12, is supported against the edge 131, this being in order to provide means for rigid axial positioning of the face member in a ratchet-like manner on the reflector 1.

Claims (20)

1. An optical system, particularly for car headlamps, comprising a glass or face member connected to the periphery of a reflector member, and wherein one of said members contains a peripheral groove inside of which is placed the peripheral edge of the other said member.

2. An optical system as claimed in claim 1, in which a connecting material such as a binder or an adhesive is placed in the bottom of the groove.

3. An optical system as claimed in claim 1, in which the bottom of the groove is provided with a compressible joint, gasket or packing.

4. An optical system as claimed in any one of the preceding claims, in which the peripheral edge of the member to be placed in the groove forms a flange.

5. An optical system as claimed in any one of the preceding claims, in which said groove and said peripheral edge have complementary ratchet-like lateral hook means.

6. An optical system as claimed in claim 5, in which the hook means are provided along the whole length of said peripheral edge and of said groove.

7. An optical system as claimed in claim 5 or claim 6, in which the lateral hook means are formed in the groove and comprise a flange or lip directed towards the interior of said groove.

8. An optical system as claimed in any one of claims 5 to 7, in which the hook means of the edge of at least one of said members forms a lateral projection.

9. An optical system as claimed in any one of the preceding claims, in which the bottom of the groove of one of said members and the peripheral edge of the other said member contain studs.

1 0. An optical system as claimed in any one of the preceding Claims, in which said peripheral edge has a peripheral notch.

11. An optical system as claimed in any one of the preceding claims, in which the member provided with the groove is made of a thermoplastic material, the two members being connected by a heat-moulded detent on said peripheral edge.

12. An optical system as claimed in any one of the preceding claims, in which the peripheral groove is formed on the reflector member and receives the peripheral edge of the glass or face member.

1 3. An optical system as claimed in claim 5, in which one at least of the lateral hooks of the peripheral edge and of the groove is defined by a zone which is hollowed out of a wall of the groove.

14. An optical system as claimed in claim 13, in which the hollow zone is closed by a membrane of material.

1 5. An optical system as claimed in claim 14, in which the hollow zone is formed in a lateral wall of the groove, the membrane being provided, in the hollow zone, from the inner side of the groove wall.

1 6. An optical system as claimed in claim 12, in which the hollowed out zone is provided in a projection forming a hook and projecting into the interior of the groove.

1 7. An optical system as claimed in claim 16, in which the projection has an inclined upper edge.

18. An optical system as claimed in any one of claims 1 3 to 17, in which the hollow zone is formed at the base of a deformation provided in the bottom of the groove.

1 9. An optical system as claimed in claim 18, in which the deformation comprises a seating at the bottom of the groove.

20. An optical system as claimed in any one of claims 6 to 1 9 when appended to claim 5, in which one at least of the lateral hooks is provided on an extension of one of said members.