GB2029954A

GB2029954A - A lamp reflector pivotable with respect to a transparent cover

Info

Publication number: GB2029954A
Application number: GB7929750A
Authority: GB
Original assignee: Societe de Signalisations Automobiles SEIMA
Current assignee: Societe de Signalisations Automobiles SEIMA
Priority date: 1978-09-01
Filing date: 1979-08-28
Publication date: 1980-03-26
Also published as: FR2434994B1; ES482294A1; GB2029954B; PT69938A; DE2934643C2; DE2934643A1; IT7924379A0; IT1122191B; FR2434994A1

Abstract

A reflector 7 of a lamp having a transparent cover 8 is pivotable about a point 15 at or near to the open end of the reflector 7. One or more pivot points 15 may be provided. <IMAGE>

Description

SPECIFICATION An optical unit, such as a vehicle headlight Technical field The present invention relates to an optical unit, such as a vehicle headlight.

Background art Vehicle headlights comprise a generally parabolic reflector, whose open end is directed towards a transparent cover or lens provided on its inner face, i.e. the face adjacent the reflector, with grooves and ribs such that a light beam of given characteristics is produced by the reflector and a bulb contained within the reflector.

Figure 1 shows a vehicle headlight located in the opening of a body 1 of the vehicle and provided with regulating means 2 which makes it possible to pivot the reflector 3 about a point 4, located approximately in the centre of the bulb 5.

This pivoting makes it possible to vary the orientation of the beam in accordance with an angle A, but also implies that the complete surface of the cover 6 is able to permit the passage and form a light beam of constant characteristics, no matter what the angular position adopted for the reflector.

Thus, considering only a central zone 6, of the cover 6 defined by angle A, it can be seen that the zone 61 must be formed in such a way that it does not modify the characteristics of the generally axial light beam produced by the bulb 5, no matter what setting of the reflector is adopted within the angle A.

As a result it is necessary to manufacture transparent covers which are extremely complex and whose optical output ratio is below that which could be obtained if the reflector were fixed relative thereto.

Statement ofinvention and advantages It is an object of the present invention to alleviate the above disadvantages and there is accordingly provided an optical unit, such as a vehicle headlight, which comprises a substantially cup-shaped reflector which is capable of carrying a light bulb substantially adjacent the base of the cup shape to direct a beam of light generally axially forwardly of the reflector, a transparent cover which overlies the open end of the substantially cup-shaped relector, and regulating means capable of adjusting the angular position of the reflector with respect to the transparent cover, and wherein the reflector is pivoted relative to the cover substantially about its open end at at least one position substantially at or axially aligned with the periphery of the cover.

Preferably an imaginery line joining the or each pivot position with an associated regulating means passes through the axis of the reflector. The or each pivot position may be determined by a contact stud provided on one of the cover and the reflector, the stud being located in an opening in the other of the cover and reflector. The opening which defines with the contact stud the pivot position or one of the pivot positions may be elongated parallel to the axis of whichever of the cover or reflector in which it is provided, and/or the opening or one of the openings may be tapered.

Furthermore, there may be provided a respective regulating means for the or each pivot position, the or each regulating means comprising an assembly of a screw and nut, one of which bears on the reflector and the other on the cover, adjustment being provided by rotation of the screw relative to the nut.

Figures in the drawings Various embodiments of optical units in accordance with the present invention will now be described by way of example only, with reference to the accompanying drawings, in which: Figure 1 is an axial sectional view of a known optical unit; Figure 2 is an axial section through a first embodiment of the optical unit according to the invention; Figure 3 is a part sectional view showing an embodiment of the pivot point of a reflector relative to a transparent cover; Figure 4 is a part section of an embodiment of the pivoting control of a reflector relative to a transparent cover; Figure 5 is a broken away perspective view of an embodiment of a transparent cover; Figure 6 is an axial sectional view of another embodiment of the optical unit, and Figures 7 and 8 are axial sections of two further embodiments of the optical unit.

Detailed description of the drawings The present invention relates to the construction of an optical unit in which the reflector and transparent cover are relatively movable, and wherein the cover may have a simplified construction and permit a good light transmission efficiency.

The optical unit shown in Figure 2 comprises an orientatable reflector 7 and a fixed transparent cover 8, opening 71 of reflector 7 being located in a plane passing through a peripheral wall 9 of the cover 8, i.e. as close as possible to the central light transmitting part of the cover.

Reflector 7 supports by means of a bulb holder 10 the light bulb 11 which is positioned along the longitudinal axis of the reflector and the cover.

Cover 8 is secured by a peripheral rib 12 thereof in a groove 13 of an opening in a vehicle body 1. This retaining of cover 8 in groove 13 is obtained with the interpositioning of a sleeve 14 made from a flexible and optionally elastic material, which is extended at least partially about the outer face of the reflector 7.

In accordance with the invention, the reflector 7 is mounted on the cover 8 so as to pivot with respect to the cover at a point 15 located in the plane of the opening 7, ofthereflectorwhere it passes through the peripheral wall 9 of the cover.

In the embodiment of Figure 2 the pivot point 15 is formed on the upper edge of the reflector by means of a contact stud 16, located in an axially elongated opening 17 in the inner face of the peripheral wall 9.

The elongated opening 17 is arranged longitudinally of the optical unit, i.e. in a plane which passes through the axis 72 of the unit.

In this embodiment the pivoting control means of the reflector with respect to the cover about point 15 is constituted by a screw 18, whose head bears against the cover 8, the screw 18 engaging with a screw-threaded nut 19 forming a slide-member located in a longitudinal groove 20 and the peripheral wall 9. A contact stud 21 formed on the outer wall of the reflector is received in a recess in nut 19. The point 15 and stud 21 lie in a plane which passes through the axis 72 of the unit.

It is readily apparent that by rotating screw 18 nut 19 is displaced in groove 20, which has the effect of pivoting reflector 7 about point 15 in such a way that plane 71 of the reflector opening can pass from a position 73 to position 74. However, in view of the position of pivot point 15 on plane 71, i.e. adjacent the light transmitting part of the cover 8, said pivoting leads to a very small modification in the position 22 of the meeting point of the optical axis of the reflector relative to the cover. In the present embodiment this modification of the positions is defined by the intersection of cover 8 and angle B.

Figure 2 is a vertical section through the optical unit and the screw/nut assembly 18/19 ensures a deviation of the light beam in a vertical plane.

However, it would also be possible to provide any other angular arrangement of the pivoting plane as a function of the configuration of the light beam and the desired direction of its setting. Furthermore, a number of pivoting planes could be provided, in order more particularly to permit a setting of the light beam in a vertical plane and in a horizontal plane.

Thus, in the embodiment of Figure 5 cover 8 has two pivot points 15 and 151 located on perpendicular lines passing through the axis 72 of the reflector to associated regulating means. These intersecting movements of the reflector are permitted as a result of the fact that the pivot points 15 and 151 are located, in the case of point 15, within an elongated opening 17, oriented longitudinally to the refelector and, in the case of point 151, within an enlarged or tapered opening 171.

As is shown in Figure 5 the regulation of the angular position of the reflector in the direction of arrows F1 and F2 is brought about by screw;nut assemblies whose nuts 19 and 191, fixed relative to the reflector, slide in respective grooves 20 and 20 of the cover 8.

However, if desired, openings 17 and 17, defining the pivot points 15 and 15, could be replaced by grooves similar to grooves 20 and 20, receiving the screw/nut assemblies 18/19 in such a way that pivot points 15 and 15, can be formed on the peripheral wall of the cover at its upper, lower, left or right points.

In the same way openings 17 and 171 for the reflector orientation are either constituted by blind holes as is for example shown in Figure 2, or by a through-opening 173 as is shown in Figure 3.

In the embodiment of Figure 2 screw 18 controlling regulating nut 19 is accessible on the front face of cover 8. However, a reverse arrangement could be provided, as is shown in Figure 4 where a screw 23 is accessibie from the rear of the optical unit on the reflector side, nut 19 receiving contact stud 21 of the reflector 7 being slidingly mounted in groove 20 in the peripheral wall 9 of the cover 8.

For certain vehicles the vertical adjustment of the optical units provided by the regulating means must on the one hand be sensitive to adapt the light beam to the regulations in force and on the other hand provide a coarse adjustment to adapt the beam relative to the inclination of the car which is varied by the load carried.

Thus, according to Figure 6 the cover 24 has in its peripheral wall 25 and in the pivot plane with pivot point 15, a recess 26 with a helical groove 27 in which is located a contact stud 28 provided on the outer face of a member 29 which receives the regulating screw 18.

Thus, by rotating screw 18, nut 19 is displaced in the groove 20 in order to ensure the desired sensitive regulation of the reflector, whilst, by use of a screwdriver on member 29, contact stud 28 moves in groove 27 in orderto rapidly regulate the position of member 29 in recess 26.

During the adjustment of member 29 screw 18, which is in engagement with the said member by means of a thread, rapidly displaces nut 19 in order to obtain the rapid regulation of the angular position of reflector 55.

In the embodiment of Figure 6 the optical ribs and grooves defining the characteristics of the light beam are provided at 55" on the inner wall of the reflector instead of on cover 24. In this case cover 24 can have local deformations 241, as a function of the sepcial characteristics of the light beam to be obtained.

As shown in Figure 6 the peripheral wall 25 of cover 24 can have, particularly on its upper edge, a passage 251 for the outflow of washing water for the outer surface of the cover. In this embodiment passage 25, issues into parallel grooves 252 covered by the forward end of sleeve 14.

In the embodiment of Figure 7 reflector 29 is provided with a rear regulating device constituted by a screw-threaded rod 30 receiving a regulating nut 31 and connected by a sleeve 30, to a member 33 locked on one of the lateral lugs 34 provided on the outside of reflector 29.

Regulating nut 31 bears on a rigid surface 32 of the vehicle body, said surface 32 being, for example, positioned within the car in the vicinity of the dashboard.

The screwing-up of nut 31 makes it possible to obtain the necessary sensitive regulation of the angular position of reflector 29. However, in this embodiment surface 32 has a number of stepped irregularities 321 permitting a tilting of the rod 30 and the rapid variation of the angular position of reflector 29.

Elastic means may be provided between the cover 35 and reflector 29 in order to bias the reflector to an initial position, and in the embodiment of Figure 7 the elastic means is constituted by the envelope 14, made from an elastic material, surrounding reflector 29 and forming at 14, a grooved positioning joint for cover 35 in the opening of vehicle body 1. In this embodiment the envelope 14 forms at 142 elastic bellows permitting the pivoting of reflector 29 and its return to its initial position as a function of the settings performed.

In the embodiment of Figure 7 pivot point 15 is cletermined buy a contact stud 36 formed at the end of a lug 34 which comprises a lateral extension of the reflector 29, said stud 36 moving in an elongated opening 37 in the peripheral wall of the cover 35.

The width of contact stud 36 essentially corresponds to the width of opening 37 in order to effect a correct guidance of the reflector and, in Figure 7, the poriton of the lug 34 carrying regulating means 30, 31,32 and 33 is also provided with a contact stud 38 which moves in an elongated opening 39 having corresponding dimensions in order to increase the precision of the transverse guidance of the reflector with respect to the cover 35.

In the embodiment of Figure 8 the control of the orientation of reflector 39 with respect to a cover 40 is obtained by a linkage 41 controlled by a servomechanism 42 dependant on an electrical or mechanical control. Said control can optionally be made automatic by subjecting the servomechanism 42 to information which is a function of the distance of the vehicle chassis from the axles and therefore a function of the vehicle load.

In the embodiments of Figures 2 to 7 the peripheral wall 9125 of the cover is continuous and the opening 43 (Figure 7) of the reflector is defined by a planar edge. However, any other arrangement could be provided and in particular the peripheral wall of the cover and the opening of the reflector could be discontinuous and to this end constituted by tags or tongues having the pivot point of the reflector with respect to the mirror or vice versa, as well as means for controlling the pivoting operation.

Thus in the embodiment of Figure 8 cover 40 is provided with moulded lugs 44 and 45 on whose outer face there are contact studs 46 and 47 respec tivelywhich move in associated elongated openings 48 and 49 formed in lugs provided on the edge of the reflector opening. In this case contact stud 46 defines the pivot point of the reflector under the action of servomechanism 42, whilst contact stud 47 constitutes a means for guiding the reflector.

Claims

1. An optical unit, such as a vehicle headlight, which comprises a substantially cup-shaped reflector which is capable of carrying a light bulb substantially adjacent the base of the cup shape to direct a beam of light generally axially forwardly of the reflector. a transparent cover which overlies the open end of the substantially cup-shaped reflector, and regulating means capable of adjusting the angular position of the reflector with respect to the transparent cover, and wherein the reflector is pivoted relative to the cover substantially about its open end at at least one position substantially at or axially aligned with the periphery of the cover.

2. An optical unit as claimed in claim 1 in which an imaginary line joining the or each pivot position with an associated regulating means passes through the axis of the reflector.

3. An optical unit as claimed in either of the preceding claims in which the or each pivot position is determined by a contact stud provided on one of the cover and the reflector, the stud being located in an opening in the other of the cover and reflector.

4. An optical unit as claimed in claim 3 in which the opening which defines with the contact stud the pivot position or one of the pivot positions is elongated parallel to the axis of whichever of the cover or reflector in which it is provided.

5. An optical unit as claimed in claim 3 or claim 4 in which the opening defining with the contact stud the pivot position or one of the pivot positions is tapered.

6. An optical unit as claimed in any one of the preceding claims in which there are two pivot positions whose axes are perpendicular to each other.

7. An optical unit as claimed in claim 6 when dependent from claim 5 in which the elongated and tapered openings are respectively located in vertical and horizontal planes including the reflector axis.

8. An optical unit as claimed in claim 3 or any claim dependent therefrom in which the or each opening is constituted by a blind hole.

9. An optical unit as claimed in any one of the preceding claims in which there is provided a respective regulating means for the or each pivot position, the or each regulating means for the or each pivot position, the or each regulating means comprising an assembly of a screw and nut, one of which bears on the reflector and the other on the cover, adjustment being provided by rotation of the screw relative to the nut.

10. An optical unit as claimed in claim 9 in which the nut forms a slide memberslidably located in a groove in one of the cover and the reflector, the screw being longitudinally restrained relative to the other of the cover and reflector.

11. An optical unit as claimed in claim 9 or claim 10 in which the screw bears on one of the reflector and cover through a movable member having a finger member located in a helical groove, displacement of the finger member in the groove providing displacement of the nut and screw assembly, and therefore a secondary regulating means.

12. An optical unit as claimed in any one of the preceding claims in which elastic means is provided for the resilient adjustment of the reflector with respect to the cover.

13. An optical unit as claimed in claim 12 in which the elastic means is constituted by a sleeve extending between the reflector and the cover.

14. An optical unit as claimed in any one of the preceding claims in which the cover has a rearwardly extending substantially peripheral extension on which the or at least one of the pivot positions is defined.

15. An optical unit as claimed in claim 14 in which the extension is continuous substantially around the periphery of the cover.

16. An optical unit as claimed in any one of the preceding claims in which the or at least one of the pivot positions is defined on a lateral extension of the reflector.

17. An optical unit substantially as herein de scribed with reference to Figure 2 of the accompanying drawings.

18. An optical unit substantially as herein described with reference to Figure 6 of the accompanying drawings.

19. An optical unit substantially as herein described with reference to Figure 7 of the accompanying drawings.

20. An optical unit substantially as herein described with reference to Figure 8 of the accompanying drawings.

21. An optical unit as claimed in claim 1 and substantially as herein described with reference to Figure 3 of the accompanying drawings.

22. An optical unit as claimed in claim 1 and substantially as herein described with reference to Figure 4 of the accompanying drawings.

23. An optical unit as claimed in claim 1 and substantially as herein described with reference to Figure 5 of the accompanying drawings.