Projector-type headlight for applications in the field of motor-cycles and/or motor cars

Abstract: A projector-type headlight for applications in the field of motor-cycles and/or motor cars which produces a high beam and a low beam comprising a light source (5), a lens (8), a reflector (3) that reflects the light produced by the light source towards the lens and a dimmer screen (2) that can be moved between two positions in a plane lying between the light source and the lens; in a first position the dimmer screen blocks part of the rays to obtain a lower beam, whilst in a second position all the light rays are allowed past in order to obtain a high beam.

Description: The present invention relates to a headlight for applications in the motoring field and particularly in the field of motor-cycles. In the motor-cycling field, in which the problem of size is of considerable importance, an optical assembly called the "projector type" has been introduced, consisting in a projector-type headlight. The known drawbacks of headlights of this type lie basically in the fact that they make it possible to obtain only the high beam function or the lower beam function, which are obtained by dimming or not dimming part of the light rays coming from the reflector. When using this type of headlight, therefore, it is necessary to add another (of the same type or different) that produces the beam not produced by the first, with a resulting increase in costs and size. The known drawback in providing a single projector-type headlight with two functions (lower beam and high beam) lies in the fact that, in the case of the lower beam function, the optical axis of the headlight must be rotated downwards through a certain angle such as to ensure that the road surface is perfectly illuminated. Consequently, when the headlight is switched to its high beam function, it is rotated downwards through the same angle as the lower beam, as foreseen by the technical solutions adopted up to now, impairing its efficiency. Therefore, when switching from one function to the other, a system for correcting the beam must be introduced so that the two beams are always optimal depending upon the function chosen. Whatever the beam correction system, it introduces not only design and application problems, but also an inevitable increase in costs. DE 3806658 discloses a headlight which allows to obtain a lowering of the high beam, by rotating a screen interposed between a light source and a lens. The upper edge of the screen arrives at most at the level of the optical axis of the headlight, thus producing a lower beam with not all rays directed downwards. The aim of the present invention is to create a projector-type headlight that provides both high beam and lower beam functions, overcoming the above disadvantages and in particular avoiding the use of costly systems for correcting the beam when passing from one function to the other. A further aim of the invention is to create a headlight for use both on motor-cycles and on motor-cars that is of reduced weight and size. Other advantages of the invention consist in the fact that it has two basic functions (high beam and lower beam), with a very small illuminating surface, or it has a dual headlight that is small in size and has a high performance for both functions. These aims are achieved by a projector-type headlight according to the invention, having the characteristics listed in appended claim 1. The headlight according to the invention produces a high beam, which is partially dimmed by means of a dimmer screen to produce a low beam, without any need for the two beams to be corrected by corrective, optical or other types of systems. Further characteristics of the invention will be made clearer by the detailed description that follows, referring to a purely exemplary and therefore non-limiting embodiment thereof, illustrated in the appended drawings, in which: Figure 1 is a sectional side view of a headlight according to the invention, with a dimmer screen in the dimming position (lower beam); Figure 2 is a sectional side view of a headlight according to the invention with the same dimmer screen in the non-dimming position (high beam). With reference in particular to Figure 1, a headlight 3 is made up by a light source 5, a lens 8, a reflector 6 that reflects the light emitted by the light source towards the lens and a lens holder cap 7. As can be seen in the figure, an electromagnet 1 which serves to operate a dimmer 2 is housed in a seat 4. The case illustrated is that of the lower beam function, in which the electromagnet is de-energized, in compliance with current safety regulations. In this position the dimmer 2 reaches above the optical axis 9 of the headlight, so as to block all the rays which, striking the half plane below the optical axis 9 in which the dimmer 2 is situated, would be refracted upward by the lens 8. With the dimmer situated above the optical axis 9, therefore, all rays reaching the lens 8 pass though it and in so doing are refracted downwards by an angle with respect to the optical axis 9 that depends on the angle of incidence on the lens. The high beam function is illustrated in Figure 2. The energized electromagnet 1 lowers the dimmer 2 beneath the optical axis, so that all the rays reach the lens 8. By so doing the unlit area of the field of vision is illuminated and a deep forward lighting beam is thus obtained. The particular surface of the reflector 6 makes it possible to keep the two beams aligned, without any need for correction systems, whilst maintaining the same excellent performance and excellent lighting of the road surface that are obtained with projector-type headlights with a single function (lower beam or high beam). It therefore makes it possible to switch from one function to the other simply by moving the dimmer screen 2 from one position to the other. The power necessary for a single headlight will be the sum of the power of the lamp and that of the electromagnet. The latter must be sufficient to ensure a steady and rapid movement of the dimmer, so as not to generate troublesome vibrations during switching from one function to the other. For this purpose shock absorbers could also be provided at the end of the stroke. Operation of the dimmer itself can also be carried out manually, by means of an electric stepper motor etc.. Obviously the preferred embodiment of the invention uses an electromagnet since this has the necessary power, restricts the overall size of the device and enables it to be of simple construction.

Claims: A projector-type headlight (3) for applications in the field of motor-cycles and/or motor cars, comprising a light source (5) and a dimmer screen (2) interposed between said light source and a lens (8), said dimmer screen (2) being movable between at least two positions: a first upper position, in which it blocks part of the rays coming from the light source (5), to obtain a lower beam, and a second lower position in which said dimmer screen (2) allows all the light rays coming from the light source (5) to pass, in order to obtain a high beam, switching between high beam and lower beam taking place solely through movement of the dimmer screen (2) without using optical correction systems characterized in that in said first upper position corresponding to a lower beam, the dimmer screen (2) is positioned so that its upper edge is situated above the optical axis (9) of the headlight (3), and in that the movement of said dimmer screen (2) takes place vertically in a plane perpendicular to the optical axis (9) of the headlight. A headlight according to claim 1, characterized in that said dimmer screen (2) is operated by means of an electromagnet (1) to which the dimmer screen (2) is fixed. A headlight according to claim 1, characterized in that said dimmer screen (2) is operated manually, or by means of an electric stepper motor. A headlight according to any one of the preceding claims, characterized in that said light source (5) is a single-filament, double-filament or gaseous discharge incandescent lamp. A headlight according to claim 2, characterized in that the position of said dimmer screen (2) corresponding to the lower beam function is the position with the electromagnet (1) de-energized. A headlight according to any one of the preceding claims, characterized in that shock absorbing means are provided at the end of the stroke of said dimmer screen (2).

Inventors: CELLA ROBERTO, LORENZI DAVIDE, CELLA, ROBERTO, LORENZI, DAVIDE
Applicants: FLII PAGANI S P A, FRATELLI PAGANI S.P.A.
Application year: 1997
Main classification: F21S8
IPC codes: F21V13, F21S8, F21V14, B60Q1