US1787470A - Head lamp - Google Patents

Description

E. P. BONE HEA-D LAMP Jan 6, 1931.

Filed Jan. 30, 1928 1 N VEN TOR.

A TTORNE Y.

My invention relates to headlamps and more particularly means therein for projecting an image from a specific pattern in the initial producing means without] requiring I v any assistance from the 1."efiectorior lens exment burns out the other will still operate and I H i 3 provide illumination sufiicient to enable the An ideal light image on the road ahead'of autoist to reach his'destination in safety. an automobile is one in: which the image is V in the general form of an isosceles triangle tion selected. for illustration,

with abroad base. This-result has been approximated by forming flutes or convolu-f tions on the reflector or lens of the headlamp however, the resultant imageis not well de- 7 fined and has dark spots or waves. Manufacturing expense also such construction." U I One of the objects of my invention is to and) cept in projection.

Patented Jan. 6, 1931 I mm 1''. mm, or cmcmnArnoriro 1 HEA LAMP Application lileil January 30,19%; -Seria1No'. 0,5 49.

In the particular embodim v U TED PATE T/ OFFICE Y cie'ntelectrical energy to render the V-filamentincandescent and unnecessary illumination'and cost'will be avoided, and this is anotherlobject of my invention. If one filaent of my invenfj Figure 1 is a vertical axial section through 3 a headlamp usingfiny novel bulb, f Fig. 2 is a diagrammatic view of the headlamp and a wall upon which the light rays are cast forming the desired image. presents a drawback to Fig. 3, a detail, is an enlarged view of the filaments of thebulb'secured to the bulb base,

7 attain such ideal illumination without any Fig. 4-, is awiring diagram of the electrical of the above imperfections or drawbacks acconnections. we 20 companying it. I accomplish-this by providing a novel incandescent lamp for the headlamp which obviates, the necessity of flutes or convolutions on the lens or reflector. Another object of my invention is'to pro- 2 vide an area of illumination immediately in front of the headlamp which is sufiiciently spread out to illuminate both sides of the road and another area ofigreater concentration to brightly light the road at a great distance from the lamp. To accomplish this, I construct the headlamp bulb with a V-shaped filamentor 'its'equivalent for the distant illumination and an elongated horizontal filament for nearer illumination, both of which may be formed as one or may be separately mounted.

Experience has shown that the V-shaped filament which is of greater concentration and illuminates the roadway a great distance ahead, is needed only when the automobile is moving at a fair rateof speed, and that when the machine is standing still or .is moving very slowly, the spread-out area of illumination provided by the horizontal filament is ample :to provide suflicient light. Therefore, I prefer to connect the V-filament to the generator of the automobile and the horizontal filament to the battery. When the automobile is standing still or when running very slowly the generator will not provide surfi- "Referring nowto the drawings, the headlamp. 1 of any suitable design has a two part casing 2 'anda plano-convex lens 3 secured to the casing in any desired manner. A reflector 27 having a flaring rim 31 is placed inside the rear part of the casing 2 and is securely. held'inposition between an annularabutment 7'on the front half of the casing and an abutment 5 on the rear half, both struck up Within the casing. 'Atranslucent screen. v60f mica or other materialis placed upright horizontally and secured to the inside of "the; casing, slightly below the axis ofthe headlamp. My novel incandescent lamp' passes through a central aperture 8 r in the rear reflector and is removably secured in any convenient manner.

The incandescent lamp consists of any suitablebase 9, through which the connections t o-the V-filament 10 above and hori-'' zontal elongated filament 11 below, pass and are firmly secured. :The filamentsare enclosed within the usualtransparent. casing 12. I A spring connection 28' supported by posts 29 and 30 makes contact between the connections in the bulb base and the contact post 4 passing out through the. casing. Referring now particularly to Fig; f the-drawings, aconnection 13 to one end of the V-fila ment' and a connection 14 to one end ofv the horizontal filament are preferably joined together and pass into a common ground 15. The connection 16 from the other end of the V-filament is connected to the generator 17, grounded at 18. The connection 19 from the other end of the horizontal filament terminates in the battery 20, grounded at 21. A polarized switch or check valve 22 is provided between the generator and battery and connected to each to prevent draining of electricity from the strike the reflector and passing out through the lens appear on the board in the general form of an isosceles triangle 25 of lesser illuminating intensity than area 23. The greater portion of the rays forming the base or lower part of the generally triangular image are formed by the horizontal filament 11 and the apex or upper part by the V filament 10. The two filaments are so placed in relation to each other and situated within the headlamp as to produce with their projected rays this ideal image. This desired image is effected from the two filaments without change of shape or refraction of rays by the reflector or lens. The shadowed or darker area 26 is formed by the screen 6 from Within the headlamp, and is intended to be cast at such position as to prevent glare inthe eyes of the driver of an opposing vehicle. The area 23 is of such intensity as to provide brilliant illumination a great distance ahead, and the area 25 is provided only a short distance in front of the lamp but is spread out to illuminate both sides of the roadway.

It can readily be seen that since the V-filament receives operative energy only from the generator, it will not be used except when the motor turns at a speed suflicient to provide the necessary current, while the horizontal filament may burn whether the motor is running or not since it is connected to the battery.

As here shown, the V-filament is placed at the focal point of the reflector above the horizontal filament but if a parabolic headlamp is used, the horizontal filament should be above rather than below since the image cast would be inverted. V

I have shown and described my invention in its preferred form, however, I do not wish to be limited to this form alone as many changes may be made without departing from the spirit of my invention and I intend cure by Letters Patent of the United States:

1. The combination with a headlamp having a screen, a reflector and a plano-convex lens, of an electric bulb adapted to cast an image ahead of the headlamp in the general form of an isosceles triangle with the base at the bottom, said bulb comprised of a base, a low concentration filament perpendicular to the axis of the headlamp to form the lower broadportion of the triangular image of lesser light intensity and a high concentration filament at the focal point of the reflector to cast the upper portion of the image of greater light intensity.

2. The combination with a headlamp having a screen, a reflector and a plano-convex lens of an electric bulb adapted to cast an image ahead of the headlamp in the general form of an isosceles triangle with the base at the bottom, said bulb comprised of a base, a horizontal elongated filament perpendicular to the axis of the headlamp to form the lower broad portion of the triangular image of lesser'light intensity and a V-shaped filament in a parallel plane with said horizontal filament to cast the upper portion or apex of the image of greater light intensity.

In testimony whereof I have hereunto set my hand.

EVAN P. BONE.

to include all forms readable on the claims.

I claim as my invention and desire to se-

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