AU2003200149A1 - Vehicle headlight with high/low beam switching mechanism - Google Patents

Description

P/00/011 Regulation 3.2

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

TO BE COMPLETED BY APPLICANT Name of Applicant: Actual Inventor: Address for Service: Invention Title: JENN FENG INDUSTRIAL CO., LTD.

JUNG-CHANG JONG CALLINAN LAWRIE, 711 High Street, Kew, Victoria 3101, Australia VEHICLE HEADLIGHT WITH HIGH/LOW BEAM SWITCHING MECHANISM The following statement is a full description of this invention, including the best method of performing it known to us:- 17/01/03,mc13153.cs, 1 VEHICLE HEADLIGHT WITH HIGH/LOW BEAM SWITCHING

MECHANISM

FIELD OF THE INVENTION The present invention relates generally to a vehicle headlight, and in particular to a mechanism for switching between high beam and low beam of the vehicle headlight.

BACKGROUND OF THE INVENTION Vehicles or automobiles are provided with headlight for driving in dark environments. The headlight comprises one or more light sources, such as bulbs, generating light beams and a reflector that reflects and selectively projects, the light beams in different angles, which are commonly referred to as "high beam" and "low beam". A conventional headlight comprises a bulb inside which two sets of lighting filaments are arranged. One of the filaments is shielded while another filament is not.

The light generated by the unshielded filament is not constrained and allowed to orient to a high and thus far location and is thus called "high.beam" while the light generated by the shielded filament is constrained to a low and thus near location and is thus called "low beam".

Figures 11 and 12 show an example of the conventional headlight construction. Two lighting filaments Al, A2 are arranged inside a bulb 'A of the headlight, respectively associated with low and high beams. A shielding member C is located below the filament Al. The light from the-filament Al is partly shielded by the shielding member C and is thus only incident onto an upper portion of a reflector B. The light is projected by the reflector B in a-low angle and thu's forming a low beam (Figure 11). Light from the filament-A2. isnot shielded: and is thus.

allowed to be completely reflected by the reflector B in a high angle, forming a high beam (Figure 12).

Some of the vehicle headlights available in the market comprise a high intensity discharge (HID) lamp for providing high luminous intensity. The HID lamp comprises a hermetic chamber inside which ions are filled. The iong discharge and generate light when a sufficient electric field is applied to the lamp. Since the light of a HID lamp is generated by electrical discharge, each HID lamp has a single light source. Thus, a vehicle headlight must be comprised of two HID lamps in order to selectively generate high beam and low beam. This apparently increases the overall costs of the headlight.

A headlight comprising a bulb movable with respect to a reflector for changing relative position therebetween is also available. By changing the relative position between the bulb and the reflector, the light beam of the bulb is projected in different angles and thus switched between "high beam" and "low beam". Since the relative position of the bulb with respect to the reflector is not fixed,. the bulb cannot be properly positioned in a focal point of the reflector all the time and the light beam cannot be properly focused. This may lead to incorrect perception of other drivers with respect to the distance between the vehicle issuing the non-properly focused light and their cars and thus causing traffic accidents.

It is thus desired to have a mechanism for switching high beam and low beam of a vehicle headlight for overcoming the above problems.

SUMMARY OF TIHE INVENTION An object of the present invention is to provide a headlight comprising a single light source, which generates properly focused light, beams for both high and low beams.

2 Another object of the present invention is to provide a headlight comprising a mechanism for switching high beam and low beam of the vehicle headlight by selectively moving shielding members to partially s-hieldasfigle and properly positioned light source of the headlight.

A further object of the present invention is to provide a mechanism for switching high beam and low beam of a vehicle headlight without moving a light source of the headlight with respect to a reflector thereby simplifying the overall structure of the headlight and reducing the costs thereof.

To achieve the above object, in accordance with the present invention, there is provided a vehicle headlight comprising a light bulb arranged inside a primary reflector. A secondary reflector is arranged between the primary reflector and the bulb. A mechanism switches between high beam and low beam of the headlight.

The switching mechanism comprises a base fixed inside the vehicle headlight and retaining the light bulb. A frame is mounted to the base. Two shielding members are pivotally mounted to the frame on opposite sides of the bulb. A control plate is pivoted to the base and driven by a solenoid between active and inactive positions.

A link bar has an end attached to the control plate and an opposite end pivoted to the shielding members whereby when the control plate is driven to the active position by the solenoid, the shielding members are rotated, by being driven by the pivotal connection between the link bar and the shielding members, to a position where the shielding members partially shield the light bulb and block light generated by' the light bulb from getting incident upon the secondary reflector and allowing a portion -of-the light to get incident onto a portion of the primary reflector thereby realizing the low beam of the vehicle headlight, and when the contro_ piate- ismoved-to the' inactive position by the solenoid, the shieldihg members are:rotated.away firom .the light bulb and allow the light to get incident onto the secondary reflector thereby realizing the high beam of the vehicle headlight.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be apparent to those skilled in the art by reading the following description of a preferred embodiment thereof, with reference to the attached drawings, in which: Figure 1 is a side elevational view of a headlight constructed in accordance with the present invention projecting a low beam; Figure 2 is similar to Figure 1 but showing the headlight projecting a low beam, together with a thin auxiliary beam; Figure 3 is similar to Figure 2 but showing a thick auxiliary beam projected by a large sized reflector; Figure 4 is similar to Figure 3 but showing the large sized reflector located closer to a low beam reflector; Figure 5 is a perspective view of the headlight in accordance with the present invention in which a switching mechanism is incorporated; Figure 6 is an exploded view of the headlight of the present invention; Figure 7 is a side elevational view of the headlight showing the switching mechanism at an active position; Figure 8 is similar to Figure 7 but showing the switching mechanism at an inactive position; Figure 9 is a top plan view of the headlight showing the switching mechanism at the active position; Figure 10 is similar to Figure 9 bit showing the switching mechanism at the inactive position; 4 Figure 11 is a side elevational view of a conventional vehicle headlight projecting a low beam; and Figure 12 is a side elevational view of the conventional vehicle headlight projecting a high beam.

DETAILED DESCRIPTION OF THE INVENTION With reference to the drawings and in particular to Figure 1, a headlight constructed in accordance with the present invention comprises an illuminator 2, such as a high intensity discharge (HID) bulb, supported inside a primary concave reflector 8. Shielding means, comprised of two shielding members 7, is arranged inside the headlight for partially shielding light from the illuminator 2. A secondary concave reflector 9 is arranged between the primary reflector 8 and the illuminator 2. The illuminator 2 comprises a light emitting center 20 located at a focal point of the secondary reflector 9, rather than a focal point of the primary reflector 8.

In a low beam condition, the shielding members 7 are at an active position whereby light from the illuminator 2 is partially shielded by the shielding members 7. The light from the illuminator 2 is only allowed to get incident onto an upper portion of the primary reflector 8 (as viewed in Figure which in turn projects the light in a low angle, forming a low beam. Since the light emitting center 20 of the illuminator 2 is not at the focal point of the primary reflector 8, the light! reflected by the primary reflector 8 is diverging and covers a large area..

The secondary reflector 9 is located at a-lower-side-of the. illuminator 2,.

substantially opposite to the upper portion of the primary-reflector 8 that reflects the low beam. When the shielding members 7 are moved to an inactive position, light from the illuminator 2 is allow to get incident onto the secondary reflector 9 and reflected thereby in a high angle; forming-an auxiliary beam; :as shown in:-Figure2 The auxiliary beam is actually a high beam but properly focused. Thus, the auxiliary beam is concentrated at a given point rather than diverging to cover a large area as a typical high beam. Thus, no undesired interference with the eyesight of the drivers of vehicle coming toward the headlight may occur. Such a properly focused auxiliary beam allows the drivers of the coming vehicles to correctly determine the distance between their vehicles and the vehicle of the headlight.

Figure 3 shows a different embodiment of the headlight, in which the secondary reflector, which is designated with reference numeral 9A for distinction, has a large surface area for generation of an auxiliary beam that is thicker than that of the embodiment illustrated in Figure 2 and may thus function as an actual high beam.

Figure 4 shows a further embodiment of the headlight in which the secondary reflector, which is designated with reference numeral 9B, is located close to the primary reflector 8. When the shielding members 7 are at the inactive position, light from the illuminator 2 is allowed to get incident onto the secondary reflector 9B to form an auxiliary beam that actually plays the same role as a high beam.

Also referring to Figures 5 and 6, the headlight comprises a holder or a base 1 attached to the primary reflector 8. The illuminator 2 is attached to the holder 1 for being positioned inside of the primary reflector 8 and substantially ati a location corresponding to the focal point of the secondary reflector 9. A switching mechanism constructed in accordance with the present invention is incorporated in the headlight for selectively and partially shielding the light generated by the illuminator 2, selectively allowing the light to get incident onto the secondary reflector 9 thereby switching between low and high beams.

The holder i defines a central bore 14 in wich -the illumriifiator 2 is received and fixed. The illuminator 2 comprises a base member 21 on-which abhulb 22, such as a HID bulb, is fixed. The base member 21 is attached to an underside of the holder 1 by any known manner with the bulb 22 extending through the bore 14.

The holder 1 has a raised portion (not labeled) partially surrounding the central bore 14. A recess 10 is defined in the raised portion for accommodating the secondary reflector 9. The secondary reflector 9 is made by for example stamping a metal plate on which a reflective surface is formed, such as by electroplating a reflective metal layer. The secondary reflector 9 has a shape and size substantially corresponding to the recess 10 to be snugly received therein. Adhesives or other known measures can be adopted to fix the secondary reflector 9 to the holder 1.

Two slits 13 are defined in a bottom surface of the recess 10. A frame defining a chamber 52 has legs 51 received in slits 13 and fixed to the holder 1 with the bulb 22 partially accommodated in the chamber 52.

Two opposite projections 11 are formed on the holder 1 for supporting oppositely extending pivots 111. A control plate 4, substantially U-shaped, has two opposite side segments connected by a central segment (both not labeled). Two opposite lugs (not labeled) corresponding to the projections 11 of the holder 1 are respectively formed on the side segments of the control plate 4 and each defines a hole 41 rotatably receiving the corresponding pivot 111 thereby pivotally attaching the control plate 4 to the holder 1.

A biasing element 3 is mounted between the holder 1 and each side segment of the control plate 4 to bias the control plate 4 to an active position, as shown in Figures 7 and 9, which will be further discussed. In the embodiment illustrated, the biasing element 3 comprises a leaf spring having an end 31 received and fixed in a slit 15 defined in the holder 1 and an opposite end 32 engaging an underside of the corresponding side segment of-the control::plate 4 for.biasing:the-.: control plate 4.

Two holes 12 are defined in the raised portion of the holder 1, each movably receiving, a stem 44 which is driven by a driving unit (not shown) arranged inside the holder 1 to move along the hole 12. Each stem 44 has a neck 442 and forms an expanded free end 441. The neck 442 of the stem 44 is received in a slot 42 defined in each side segment of the control plate 4 and fixed together by the expanded end 441 engaging the side segment of the control plate 4. When the stems 44 are driven by the driving unit into the holes 12, the control plate 4 is moved by the stems 44, against the biasing elements 3, from the active position showing Figures 7 and 9 toward an inactive position as shown in Figures 8 and The shielding members 7 are pivotally mounted to the frame 5 on opposite sides of the bulb 22 by means of pivot shafts 73 extending through aligned holes 53, 71 defined in the frame 5 and the shielding members 7 whereby the shielding members 7 are rotatable with respect to the bulb 22. A link bar 6 has a first end coupled to the control plate 4 and an opposite second end forming two lugs 61 corresponding to the shielding members 7. Each lug 61 forms a slot 611. A connection shaft 731 extends through the slot 611 of each lug 61 of the link bar 6 and a hole 72 defined in the corresponding shielding member 7 whereby when the link bar 6 is moved by the rotation of the control plate 4 about the pivots 111, the shielding members 7 are driven by the connection shafts 731 to rotate about the pivot shafts 73 between the active position shown in Figures 7 and 9 and the inactive position shown in Figures 8 and In the embodiment illustrated, the connection shaft 731 is attached to the pivot shaft 73 by a cross bar (not labeled) whereby the connection shaft 731 and the pivot shaft 73 form a unitary, J-shaped member. However,it is apparent-to-those having ordinary skills to provide separate pivot shaft 73 and connection shaft 731 for achieving the same functions.

The first end of the link bar 6 forms two opposite slits 62 on, opposite edges thereof. The central segment of the control plate 4 defines a notch 43 sized to receive the first end of the link bar 6 therein with an edge of the notch 43 received in and engaging the slits 62 of the link bar 6 to couple the link bar 6 to the control plate 4.

The raised portion of the holder 1 may form a passageway 16 for accommodating and guiding the movement of the link bar 6.

Referring to Figures 7-10, when the driving unit is not actuated and the control plate 4 is biased by the biasing elements 3 to the active position as shown in Figures 7 and 9, the shielding members 7 that have an extension having an L-shaped cross section, partially cover and shield the bulb 22 on opposite sides and. top side (Figure 9) thereof, whereby the light from the bulb 22 is partially blocked from being incident upon the upper portion of the primary reflector 8. The light beam iprojected by the primary reflector 8 is thus directed toward a low angle and realizing a low beam as discussed previously.

By actuating the driving unit, the control plate 4 is moved by means of the stems 44 to the inactive position as shown in Figures 8 and 10. The shielding members 7 are moved away from and thus exposing the bulb 22 toward the secondary reflector 9 that is located on the lower side of the bulb 22 (Figure 10). The light generated by the bulb 22 gets incident onto the secondary reflector 9, which in turn projects the light with a high angle and thus realizing a high beam.

The driving unit that drives the stems 44 and thus the control plate 4 can be of any known structure. For example, an electrically-excited magnetic force generation device, such as'a solenoid, can be employed to attra'ct_-and move the stems f 44 that are made of ferromagnetic materials. Alternatively, a mechanical coupling can be employed to couple the stems 44 to the driving unit. The structure of the dri ving unit is beyond the scope of the present invention and will not be further discussed herein.

Although the present invention has been described with reference to the preferred embodiment thereof, it is apparent to those skilled in the art that a variety of modifications and changes may be made without departing from the scope of the present invention which is intended to be defined by the appended claims.

Where the terms "comprise", "comprises", "comprised" or "comprising" are used in this specification, they are to be interpreted as specifying the presence of the stated features, integers, steps or components referred to, but not to preclude the presence or addition of one or more other feature, integer, step, component or group thereof.

17/01/03,mcl 3153.speci,10

Claims (14)

1. A headlight comprising: a light source generating a light; a primary reflector; a secondary reflector having a focal point at which a light emitting point of the light source is located; and a shielding device movable between an active position wherein light from the light source is prevented from getting incident onto the secondary reflector and is partially incident onto a portion of the primary reflector to be projected in a low angle to realize a low beam and an inactive position wherein light is allowed to get incident onto the secondary reflector to be projected in a high angle to realize a high beam.

2. A mechanism for switching between first and second status of a vehicle headlight comprising a light source, the mechanism comprising: a base fixed inside the vehicle headlight; at least one shielding member pivotally mounted to the base by a pivot shaft to be movable between first and second positions; a driving unit coupled to the shielding member for selectively moving the shielding member from the first position to the second position; wherein when the shielding member is at the first position, the shielding member partially shields the light source and blocks a portion of light generated by the light source thereby realizing the first status of the vehicle headlight, and when the shielding member is at the second position, the shielding member is moved away from the light source and no longer blocks the light generated by the light source thereby realizing the second status of the vehicle headlight.

3. The mechanism as claimed in Claim 2, wherein a control plate is pivoted to the base and biased toward the first position by a biasing element, a link bar having a first end attached to the control plate and a second end pivotally attached to the shielding member at a position different from the pivot shaft whereby when the control plate is forced by the driving unit against the biasing element toward the second position, the link bar rotates the shielding member toward the second position.

4. The mechanism as claimed in Claim 3, wherein the biasing element comprises a leaf spring.

The mechanism as claimed in Claim 3 or Claim 4, wherein the control plate defines a slot, and wherein a stem movable with respect to the base between the first and 1117/01/03mc3153. ll 1 7Ai1/03,mel 3153.spci, 11 second positions by being driven by the driving unit has a neck portion received in and engaging the slot of the control plate for coupling the control plate to the driving unit.

6. The mechanism as claimed in any one of Claims 2 to 5, further comprising a frame mounted to the base, two shielding members being pivoted to the frame on opposite sides of the light source by pivot shafts, the shielding members being coupled to the driving unit to be driven thereby between the first and second positions.

7. The mechanism as claimed in Claim 6, wherein the shielding!members comprise an L-shaped extension.

8. The mechanism as claimed in Claim 6 or Claim 7, wherein the coupling between the shielding members and the driving unit comprises a link bar forming two lugs each defining a slot, a connection shaft extending through the slot of the lug and a hole defined in the corresponding shielding member whereby when the link bar is driven by the driving unit, the shielding member is rotated between the first and second positions.

9. The mechanism as claimed in Claim 8, wherein the connection shaft is attached to the pivot shaft by a cross bar to form a unitary member.

The mechanism as claimed in any one of Claims 2 to 9, wherein the driving unit comprises an electrically-excited device.

11. The mechanism as claimed in Claim 10, wherein the electrically-excited device comprises a solenoid.

12. The mechanism as claimed in any one of Claims 2 to 11, comprising a primary reflector in which the light source is arranged, wherein in the first status of the headlight, light from the light source being partially shielded by the shielding member and getting incident onto a portion of the primary reflector to be projected in a low angle forming a low beam.

13. The mechanism as claimed in Claim 12, further comprising a secondary reflector arranged between the primary reflector and the light source, wherein in the second status of the headlight, the light is not shielded by the shielding member and is allow to get incident onto the secondary reflector to be projected in a high angle to form a high beam.

14. A headlight, substantially as described herein with reference to the accompanying drawings. 12 ,1 7/01/03,mcl 3153.speci12 A mechanism for switching between first and second status of a vehicle headlight, substantially as described herein with reference to the accompanying drawings. DATED this 17 th day of January, 2003 JENN FENG INDUSTRIAL CO., LTD. By their Patent Attorneys: CALLINAN LAWRIE 11/01/03,mc I3153.peci13