GB2079432A - A headlamp for a motor vehicle - Google Patents

Abstract

A headlamp, primarily for use as a fog lamp, has a single filament halogen bulb 4, held and positioned in the reflector of the headlamp by a support member 5 rigid with the reflector, and a screen 8 disposed between the lens and the lamp to suppress light rays emitted directly towards the lens 3. A second screen 9 is located between the reflector 2 and the bulb 4 in such a way that it prevents any unwanted rays created by heating of the electrodes 4b of the filament 4a from being reflected by the reflector. <IMAGE>

Description

SPECIFICATION A headlamp for a motor vehicle The present invention concerns a headlamp, primarily for use as a motor vehicle fog lamp, having a single filament halogen bulb held and positioned in the headlamp reflector by a support member rigid with the reflector, a screen being disposed between the lens and the bulb to suppress light rays from the bulb emitted in a direction towards the lens.

The bulbs of such headlamps generally have electrodes of sufficient thickness, or which are spiralled, to avoid them becoming overheated and possibly emitting unwanted light rays; in other halogen bulbs, such as H3 bulbs, the electrodes are of the same diameter as the wire of the filament and are rectilinear, as a result of which they heat up to an extent such that they sometimes emit unwanted rays.

According to the present invention a headlamp of the kind referred to above is provided with a second screen disposed between the reflector and the bulb and arranged so that it substantially prevents any unwanted rays created by heating of the electrodes of the filament from being reflected by the reflector.

The invention will now be described, by way of example, with reference to the accompanying drawings in which Figure 1 is a view, partly in cross-section, of one form of the headlamp of the invention; Figure 2 is a plan view of a metal blank for forming a screen to be used in the headlamp of Figure land Figure 3 is a view of the screen, after forming and secured to a bulb support element.

Referring to Figure 1 of the drawings, the headlamp 1 has a reflector 2, a lens 3 of which the patterns and surface provide a lighting beam suitable for driving in foggy weather, a bulb 4 of the H3 type, of which the filament 4a is located substantially in front of or at the focus of the parabolic reflector 2, a support 5 for the bulb 4, itself retained on the support 5 by a spring 6, and a screen 7 fixed to the support 5.

The screen 7 includes a portion 8 shaped and arranged to suppress the light rays emitted by the bulb 4 directly towards the glass 3, as well as those emitted by the nose 4c located at the end of the envelope of the bulb 4, and it also acts to provide a horizontal cut-off of the light beam emitted.

According to the invention, the screen 7 has a portion 9 located between the bulb 4 and the reflector 2 so as to prevent any light rays emitted by the electrodes 4b of the filament 4a from being reflected by the reflector 2 and consequently to prevent the propagation of spurious illumination.

The screen 7 is made from a metal blank cut to the shape shown in Figure 2.

Referring to Figure 2, the blank has a rectangular base portion 14, in the lengthwise extension of which is an ear 10 having a pair of divergent sides 10a joined by an outwardly curved end 10b. Each side of the portion 14 has an extension constituted by a wing 11 and a lug 12 which itself includes a small lug 13 extending in the opposite direction to the ear 10.

The screen 7 is formed by folding the blank in the following manner; the ear 10 is lifted up by bending along the broken line bb, the two wings 11, 12 are lifted up by bending along the broken lines aa and cc, the ends of the lugs 12 are then bent over along the broken line dd until their free ends 1 2a are as close as possible to one another. In the example shown, these two ends 1 2a come into contact, but a slight spacing may be retained if desired.

The shield thus obtained, seen clearly in Figure 3, is assembled on the support 5 and held thereon by means of the lugs 13 which are housed in notches 5a of the support and bent back against the underside of the support so that the latter is gripped between the shield and the lugs 13 and the shield is thereby held firmly on the support.

A screen 7 is thus obtained in a simple and economic manner and gives very satisfactory optical results by preventing the propagation of spurious illumination arising from the bulb electrodes.

1. A headlamp, primarily for use as a motor vehicle fog lamp, having a single filament halogen bulb held and positioned in the headlamp reflector by a support member rigid with said reflector, a first screen being disposed between the lens and the bulb to suppress light rays from the bulb emitted in a direction towards the lens and a second screen being disposed between the reflector and the bulb and arranged so that it substantially prevents any unwanted rays created by heating of the electrodes of the filament from being reflected by the reflector.

2. A headlamp according to Claim 1, wherein the first and second screens are made in one piece.

3. A headlamp according to Claims 1 and 2, wherein the first and second screens obtained by forming a cut-out metal blank and bending itto the required shape, the screens being provided with fixing means for fixing it on the support member.

4. A headlamp according to Claim 3, wherein the fixing means are constituted by two lugs which pass through holes in the support member and are bent over against a surface of the support member.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (4)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION A headlamp for a motor vehicle The present invention concerns a headlamp, primarily for use as a motor vehicle fog lamp, having a single filament halogen bulb held and positioned in the headlamp reflector by a support member rigid with the reflector, a screen being disposed between the lens and the bulb to suppress light rays from the bulb emitted in a direction towards the lens. The bulbs of such headlamps generally have electrodes of sufficient thickness, or which are spiralled, to avoid them becoming overheated and possibly emitting unwanted light rays; in other halogen bulbs, such as H3 bulbs, the electrodes are of the same diameter as the wire of the filament and are rectilinear, as a result of which they heat up to an extent such that they sometimes emit unwanted rays. According to the present invention a headlamp of the kind referred to above is provided with a second screen disposed between the reflector and the bulb and arranged so that it substantially prevents any unwanted rays created by heating of the electrodes of the filament from being reflected by the reflector. The invention will now be described, by way of example, with reference to the accompanying drawings in which Figure 1 is a view, partly in cross-section, of one form of the headlamp of the invention; Figure 2 is a plan view of a metal blank for forming a screen to be used in the headlamp of Figure land Figure 3 is a view of the screen, after forming and secured to a bulb support element. Referring to Figure 1 of the drawings, the headlamp 1 has a reflector 2, a lens 3 of which the patterns and surface provide a lighting beam suitable for driving in foggy weather, a bulb 4 of the H3 type, of which the filament 4a is located substantially in front of or at the focus of the parabolic reflector 2, a support 5 for the bulb 4, itself retained on the support 5 by a spring 6, and a screen 7 fixed to the support 5. The screen 7 includes a portion 8 shaped and arranged to suppress the light rays emitted by the bulb 4 directly towards the glass 3, as well as those emitted by the nose 4c located at the end of the envelope of the bulb 4, and it also acts to provide a horizontal cut-off of the light beam emitted. According to the invention, the screen 7 has a portion 9 located between the bulb 4 and the reflector 2 so as to prevent any light rays emitted by the electrodes 4b of the filament 4a from being reflected by the reflector 2 and consequently to prevent the propagation of spurious illumination. The screen 7 is made from a metal blank cut to the shape shown in Figure 2. Referring to Figure 2, the blank has a rectangular base portion 14, in the lengthwise extension of which is an ear 10 having a pair of divergent sides 10a joined by an outwardly curved end 10b. Each side of the portion 14 has an extension constituted by a wing 11 and a lug 12 which itself includes a small lug 13 extending in the opposite direction to the ear 10. The screen 7 is formed by folding the blank in the following manner; the ear 10 is lifted up by bending along the broken line bb, the two wings 11, 12 are lifted up by bending along the broken lines aa and cc, the ends of the lugs 12 are then bent over along the broken line dd until their free ends 1 2a are as close as possible to one another. In the example shown, these two ends 1 2a come into contact, but a slight spacing may be retained if desired. The shield thus obtained, seen clearly in Figure 3, is assembled on the support 5 and held thereon by means of the lugs 13 which are housed in notches 5a of the support and bent back against the underside of the support so that the latter is gripped between the shield and the lugs 13 and the shield is thereby held firmly on the support. A screen 7 is thus obtained in a simple and economic manner and gives very satisfactory optical results by preventing the propagation of spurious illumination arising from the bulb electrodes. CLAIMS

1. A headlamp, primarily for use as a motor vehicle fog lamp, having a single filament halogen bulb held and positioned in the headlamp reflector by a support member rigid with said reflector, a first screen being disposed between the lens and the bulb to suppress light rays from the bulb emitted in a direction towards the lens and a second screen being disposed between the reflector and the bulb and arranged so that it substantially prevents any unwanted rays created by heating of the electrodes of the filament from being reflected by the reflector.

2. A headlamp according to Claim 1, wherein the first and second screens are made in one piece.

3. A headlamp according to Claims 1 and 2, wherein the first and second screens obtained by forming a cut-out metal blank and bending itto the required shape, the screens being provided with fixing means for fixing it on the support member.

4. A headlamp according to Claim 3, wherein the fixing means are constituted by two lugs which pass through holes in the support member and are bent over against a surface of the support member.