Tri-beam roadway-lighting system for motor vehicles

• US 3,894,227 A
• Filed: 10/10/1974
• Issued: 07/08/1975
• Est. Priority Date: 02/25/1974
• Status: Expired due to Term

• Current Assignee: Philips Electronicsnorth America Corporation (Koninklijke Philips N.V.)
• Original Assignee: Elam Pitkjaan, Leland W. Leseur
• Inventors: Pitkjaan, Elam, LeSeur, Leland W.
• Primary Examiner(s): Sheer, Richard M.
• Application Number:
  US05/513,917
• Time in Patent Office: 271 Days
• Field of Search: 240/7.1,7.1A,41.35R 315/82,83
• US Class Current: 362/543
• CPC Class Codes: B60Q 1/1415 Dimming circuits
• CPC Class Codes: F21S 41/00 Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps reversing lights F21S43/00
• CPC Class Codes: F21S 41/14 characterised by the type of light source
• CPC Class Codes: F21S 41/162 Incandescent light sources, e.g. filament or halogen lamps
• CPC Class Codes: F21S 41/164 having two or more filaments
• CPC Class Codes: F21S 41/168 having a filament arranged transversally to the optical axis of the illuminating device
• CPC Class Codes: F21S 41/192 Details of lamp holders, terminals or connectors
• CPC Class Codes: F21S 41/28 Cover glass
• CPC Class Codes: F21S 41/321 the reflector being a surface of revolution or a planar surface, e.g. truncated
• CPC Class Codes: F21S 41/40 characterised by screens, non-reflecting members, light-shielding members or fixed shades
• CPC Class Codes: F21S 41/43 characterised by the shape thereof
• CPC Class Codes: F21S 41/47 Attachment thereof achieving variable light distribution by movable screens F21S41/683

Abstract

Four headlamps are mounted in paired relationship on the front of the vehicle and energized in various combinations (two, three and four-headlamp sequence) to provide a low-beam, a mid-beam and a high-beam lighting mode, respectively, each of which has a light distribution pattern that provides improved illumination of the roadway under various driving and traffic conditions with a minimum of glare. One lamp in each pair of headlamps contains dual light sources, one of which is used for the low-beam lighting mode and the other of which is used for the high-beam light mode. The remaining headlamp in each pair contains a single light source and one of these lamps serves as a mid-beam lamp that is energized with the two low-beam light sources to provide the mid-beam lighting mode. The other single-light source lamp constitutes a high-beam headlamp that is energized along with the mid-beam lamp and two high-beam light sources to provide the high-beam lighting mode.

Claims

1. A tri-beam roadway-lighting system for a motor vehicle comprising, In combination;

four headlamps mounted on the front of the motor vehicle with a pair of headlamps disposed on each side of the centerline thereof, one headlamp in each of said pairs of headlamps comprising a dual-function headlamp having a lens, a reflector with a focal point, and a pair of light sources one of which is disposed in on-focus relationship and the other of which is disposed on off-focus relationship with said reflector, said on-focus light sources when energized producing low-beam illumination and a low-beam lighting mode, another headlamp in either one of said pairs of headlamps comprising a mid-beam headlamp having a lens, a reflector with a focal point, a single compact light source which is positioned adjacent said focal point, and a shield that is disposed in front of and in masking relationship with said compact light source, said mid-beam headlamp when energized producing a beam of light which supplements the low-beam illumination produced by said on-focus light sources and thereby provides a mid-beam lighting mode, the remaining headlamp in said pairs of headlamps comprising a high-beam headlamp that has a lens, a reflector with a focal point, and a single on-focus light source which, when energized in conjunction with said mid--beam headlamp and the off-focus light sources in said dual-function headlamps, produces a highbeam mode of illumination, and circuit means for energizing said headlamps and light sources in the aforesaid sequence including (a) a main two-position switch operable in one position to connect only the two on-focus light sources in said dual-function headlamps to the electrical power supply of the vehicle and thereby providing said low-beam lighting mode, and (b) an auxiliary two-position switch operable in one position to connect the mid-beam headlamp to the two on-focus light sources in the dual-function headlamps, said auxiliary switch in its other position being operable to connect the two off-focus light sources in said dual-function headlamps to the light sources in said mid-beam and high-beam headlamps, said main switch in its other position being operable to connect said auxiliary switch to the electrical power supply of the vehicle.

2. The vehicular tri-beam headlighting system of claim 1 wherein each of said reflectors is of generally paraboloidal configuration.

3. The vehicular tri-beam headlighting system of claim 2 wherein;

both of said dual-function headlamps and said high-beam headlamp have prismatic type lenses, and said mid-beam headlamp has a lens with flutes that extend across the lens in a vertical direction and constitute the sole light-modifying means associated with said lens.

4. The tri-beam headlighting system of claim 3 wherein each of said lenses have a plurality of spaced projecting elements on their outer surfaces which are oriented to permit the respective headlamps to be aimed by mechanical means.

5. The vehicular tri-beam headlighting system of claim 1 wherein each of said lenses is of the prismatic type and have a plurality of spaced projections on their outer surfaces oriented to permit the headlamps to be aimed by mechanical means.

6. The vehicular tri-beam headlighting system of claim 1 wherein the light sources in said mid-beam headlamp and said high-beam headlamp both comprise halogen incandescent lamps.

7. The vehicular tri-beam headlighting system of claim 6 wherein the pair of light sources in each of said dual-function headlamps comprise a pair of filaments that are sealed in a halogen-containing envelope.

8. The vehicular tri-beam headlighting system of claim 1 wherein each of the dual-function headlamps also contain a shield that is disposed in front of and in making relationship with the on-focus light sources in the respective headlamps.

9. The vehicular tri-beam headlight system of claim 1 wherein;

each of said headlamps is of the sealed-beam type, the light source in said high-beam headlamp and the two on-focus lIght sources in said dual-function headlamps each have substantially the same nominal wattage rating, and the light source in said mid-beam headlamp and the two off-focus light sources in said dual-function headlamps have nominal wattage ratings that are substantially the same but lower than the nominal wattage rating of the light source in said high-beam headlamp.

10. The vehicular tri-beam headlighting system of claim 9 wherein the light sources in each of said sealed-beam headlamps comprise coiled refractory wire filaments.

11. The vehicular tri-beam headlighting system of claim 9 wherein each of said sealed-beam headlamps are of the PAR 46 type and each of said light sources comprise coiled filaments of the C-6 type.

12. The vehicular tri-beam headlighting system of claim 1 wherein;

the reflector of said mid-beam headlamp is divided into two hemiparabolic segments which are axially offset relative to one another and have focal points that are apaced from one another along the optical axis of the reflector, and the single compact light source in said midbeam headlamp extends between said spaced focal points.

13. The vehicular tri-beam headlighting system of claim 12 wherein the lens of said mid-beam lamp has a plurality of flutes on its inner surface that extend vertically across the lens, and said flutes constitute the sole light-bending means associated with said lens.

14. The vehicular tri-beam headlighting system of claim 13 wherein;

said dual-function headlamps and said high-beam headlamp each have paraboloidal-shaped reflectors and prismatic type lenses, and each of the lenses have a plurality of spaced outwardly-projecting pads on their outer surfaces that are oriented to permit the headlamps to be aimed by mechanical means.

15. The vehicular tri-beam headlighting system of claim 12 wherein each of said headlamps is fitted with a prismatic type lens that has a plurality of spaced projections on its outer surface which are oriented to permit the respective headlamps to be aimed by mechanical means.

16. The vehicular tri-beam headlighting system of claim 15 wherein each of said headlamps is of the sealed-beam type.