GB2041189A

GB2041189A - Multi-purpose rear light for road vehicles

Info

Publication number: GB2041189A
Application number: GB8002555A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1979-01-25
Filing date: 1980-01-25
Publication date: 1980-09-03
Also published as: FR2447515B1; DE2902772C2; DE2902772B1; GB2041189B; FR2447515A1

Abstract

A multi-purpose rear light for road vehicles, for installation optionally and interchangeably at the right or left side of the vehicle, includes a baseplate 1 supporting a transparent cover (2) comprising at least two-equal-sized light-transmitted zones disposed symmetrically on either side of the vertical middle line of the cover. A reflector 25 is secured detachably to the baseplate optionally at either side of it, for reflecting light from a lamp through whichever of the two light-transmitting zones is being used for the fog tail light of the vehicle. Each of the two light-transmitting zones, such as (5) for the brake light and (6) for the fog tail light, comprises an inner Fresnel step-lens system 31 surrounded by an outer prism system 32, at least the Fresnel step-lens system 31 being covered over by a system 33 of parallel rod-lenses 34 adapted to be disposed vertically. <IMAGE>

Description

SPECIFICATION Multi-purpose rear light for road vehicles The invention relates to a multi-purpose rear light for road vehicles, as described in the preamble of ciaim 1.

A multi-purpose rear light of this kind is known from the German Offenlegungsschrift 27 26 933. This known light has a transparent cover with two light-transmitting zones which are constructed in such a way that by shifting a reflector in position on the base plate either of the two light-transmitting zones of the transparent cover can be utilised for the fog tail light, the other serving for the brake light of the vehicle.

Nevertheless it has been found in practice that satisfactory results cannot be obtained simply by shifting the reflector in position, from the right to the left or vice versa, unless the two zones of the transparent cover are of special optical construction. This is because on the basis of the official regulations the beam of light delivered by the fog tail light has to differ in several respects from the beam delivered by the brake light. The fog tail light must project a beam with a light intensity of at least 1 50 cd, the beam extending over an angle of + /- 10, horizontally and + /- 5" vertically, relative to the optical axis, and the light intensity must not exceed 300 cd in any direction.The specifications for a brake light, on the other hand, require that the light intensity in the beam must be between 40 cd and 100 cd, but this is specified only for the optical axis. In both cases only a narrow range of light intensities is therefore available over the entire area of each light-transmitting zone of the transparent cover. The fog tail light, in particular, requires a very carefully constructed transparent cover in order to ensure sufficient light intensity from the edges of the zone, and not too much from the middle.

In the fog tail lights of known construction it is difficult to achieve a sufficiently even distribution of the beam. The transparent cover has a system of rectangular honeycomb lens fields which tend to give insufficient light intensity near their edges, or too much in the middle.

In attempting to remedy the matter a multipurpose rear light for road vehicles has been developed whose transparent cover has two zones which are optically different from each other: one for the fog tail light, the other for the brake light. The two zones are equal-sized and positioned symmetrically on either side of the vertical middle line of the transparent cover. The optical system for the brake light consists of a rectangle of Fresnel step-lenses surrounded by stepped prisms. The optical system for the fog tail light is a system of rodlenses dimensioned to agree with the zone for the brake light.

But manufacture of the transparent cover is comparativeiy complex. Each zone is injectionmoulded individually as a panel, which is then fitted into the main body of the transparent cover and welded in place. The resulting transparent cover is asymmetric because the two zones differ from each other. Consequently two different transparent covers are required, one for mounting on the left rear end of the vehicle, the other for the right rear end. This doubles the stock which has to be kept on the shelves.

The intention in the present invention, starting out from the multi-purpose rear light described at the beginning, is to construct the two light-transmitting zones, for the brake light and for the fog tail light, the same as each other, each capable of providing adequately either kind of beam so that merely by shifting the detachable reflector from the one side to the other of the baseplate the light can be attached to either side of the vehicle, the same transparent cover being used.

The problem is solved, according to the invention, in that each of the two light-transmitting zones comprises an inner Fresnel steplens system surrounded by an outer prism system, at least the Fresnel step-lens system being covered over by a system of rod-lenses positioned vertical and parallel to each other.

In the rear light of the present invention the two zones of the transparent cover are-there- fore exactly the same as each other, each having an inner Fresnel step-lens system surrounded by an outer prism system, at least the Fresnel step-lens system being formed by a side-by-side array of parallel rod-lenses. In changing over from a right-side rear light to a left-side one all that is necessary is to ensure that the detachable reflector is positioned where the fog tail light should be.

The arrangement not only simplifies assembly of the light but also, due to the fact that the two zones of the transparent cover are the same as each other, simplifies manufacture and reduces storage space, in that only one kind of transparent cover has to be manufactured and stocked. The two zones are injection-moulded in one operation with the remainder of the transparent cover, no fitting and welding being required. And only one kind of baseplate is necessary, with a reflector which is detachable so that it can be shifted in position from the one side to the other of the baseplate.

The rear light according to the invention is manufactured and sold as a unit for use at either side of the vehicle. In each case one of the zones is used for the fog tail light, the other for the brake light. If no fog tail light is required, then both the zones can be used for the brake light merely by omitting the detachable reflector.

In a preferred version of the invention the rod lenses are convex in cross-section and together form a rectangular field extending over the Fresnel step-lens system. If necessary, the rod-lens field can even extend over a portion of the surrounding prism system, in order to widen the fog tail light beam and increase its intensity. In this case the brake light appears as a bright centre in a dark surround, even through it has the specified intensity. To distribute the brightness more evenly two brake light reflectors can, if desired, be moulded into the baseplate between the attachment clips for the fog tail light reflector, the brake light reflector which is not in use being masked by the mirror-finished fog tail light reflector.

Further details and advantages of the invention can be derived from the following description of the example represented in the drawing, in which: Figure 1 shows the transparent cover of a multi-purpose rear light for a road vehicle, as seen from behind the vehicle on which the light is mounted; Figure 2 shows the light with the transparent cover removed; Figure 3 is a partly sectioned view from above; Figure 4 is an enlarged view from behind of a portion of the transparent cover; Figure 5 is a section through this portion of the transparent cover, taken in the plane V-V of Fig. 4; Figure 6 is a corresponding section taken in the plane VI-VI of Fig. 4.

The multi-purpose rear light for road vehicles comprises a baseplate 1 made of a synthetic resin and supporting a cover 2 which is made of a transparent synthetic resin. The cover 2 is subdivided into several fields, or zones, each tinted and contoured in section to fulfil its own particular function. The lower zone 4, extending all the way across the cover, is tinted red and is for the ordinary tail light of the vehicle. Above this, in the middle, is a yellow-tinted zone 3 for a blink-light, or it can be colourless for a spotlight. The yellowtinted or colourless zone 3 is at least 100 mm wide and projects backwards somewhat beyond the rear face of the cover, as shown in Fig. 3.On each side of the middle zone 3 there is a red-tinted zone 5, 6, these two zones of the cover having the same size and the same construction as each other but serving different purposes, whereas the one redtinted zone, for example 5, is for the brake light of the vehicle, the other, in this case 6, is for the fog tail light.

In Fig. 2 a square reflector 25 is shown for reflecting extra light from a lamp through the red-tinted zone 6 of the fog tail light. The square reflector 25 is clipped in place on the baseplate 1 over one of two circular reflectors 27, 26, which are for the brake light. The necessary spring clips 23, 24, 21, 22 on the baseplate 1 are arranged so that the square reflector 25 can be positioned either near the right-hand end, as shown in Fig. 2, or near the left-hand end of the baseplate 1. Thus either of the two red-tinted zones 6 or 5 can serve for the fog tail light. To facilitate correct installation, that is to ensure that the square reflector 25 is installed near the proper end of the baseplate 1, to suit the intended applica tion of the rear light on the right or left side of the vehicle, the square reflector 25 is clearly marked "FOG TAIL LIGHT".And the square reflector 25, once it has been clipped in place, masks one of the two "STOP" notices printed on the baseplate. The uncovered circular reflector, in this case 26, is for the brake light, as indicated by the displayed legend "STOP".

A portion of the optical system is represented in Figs. 4, 5 and 6. These figures show a zone of the transparent cover 2 which serves, depending on the position of the square reflector 25, either for the fog tail light when backed by the square reflector 25, or for the brake light when backed by the uncovered one of the two circular reflectors 27, 26. In the middle region of the zone the transparent synthetic resin has been injection moulded to form a Fresnel step-lens system 31 and surrounding this are the concentric rings 32 of a prism lens sytem. The Fresnel step-lens system 31 is covered over by a rodlens system 33 in the form of a rectangle of vertical and parallel rod lenses 34 extending over the step-lens system 31 and partly over the surrounding prism-lens system 32. The rod-lens system 33 preferably consists of rod lenses 34 which are convex in cross-section.

The circular reflectors 27, 26 for the brake light are moulded in place between pairs of clips 23, 24 and 21, 22. If the baseplate 1 is made of a suitably reflective substance the circular reflectors 27, 26 need not be given a special mirrored finish.

Claims

1. A multi-purpose rear light for road vehicles, for installation optionally at the right or left side of the vehicle, with a base-plate supporting a transparent cover comprising at least two equal-sized light-transmitting zones disposed symmetrically on either side-of the vertical middle line of the cover; and with a reflector secured detachably to the baseplate optionally at either side of it, for reflecting light from a lamp through whichever of the two light-transmitting zones is being used for the fog tail light of the vehicle, characterised in that each of the two light-transmitting zones, such as (5) for the brake light and (6) for the fog tail light, comprises an inner Fresnel step-lens system (31) surrounded by an outer prism system (32), at least the Fresnel step-lens system (31) being covered over by a system (33) of parallel rod-lenses (34) adapted to be disposed vertically.

2. A multi-purpose rear light as claimed in claim 1, characterised in that the rod-lens system (33) consists of rods (34) which are convex in cross-section and extends as a rectangle over the step-lens system (31).

3. A multi-purpose rear light as claimed in claims 1 or 2, characterised in that the rodlens system (33) extends beyond the Fresnel step-lens system (31) into the surrounding prism system (32).

4. A multi-purpose rear light as claimed in one of the claims 1 to 3, characterised in that the baseplate (1) has attachment clips (21, 22, 23, 24) for retaining the fog tail light reflector (25), there being mounted into the baseplate (1), between the clips, two reflectors (26, 27) for the brake light, these reflectors (26, 27) being positioned so that one of them is each time masked by the fog tail light reflector (25), which one depending on the selected position of the fog tail light reflector (25).

5. A multi-purpose rear light for road vehicles substantially as hereinbefore described with reference to the accompanying drawings.