US1460511A - Headlight - Google Patents

Description

july 3, 1923.

l 1,460,511 J. M. RICHARDSON HEADLIGHT Filed Aug. 28, 1919 J/We @Umm/500,

Patented July 3, 1923.

UNITEDv STATES 1,460,511 PATENT OFFICE.

JAMES M. RICHARDSON, OF HIGHLAND PARK, MICHIGAN, ASSIGNOR TO `TULI'IE AUTO BULB COMPANY, OF NEW YORK, N. Y., A CORPORATION 0F MICHIGAN.

HEADLIGHT.

Application illed August 28, 1919. Serial No. 320,406.

7 10 all trimm 'it may concern lie it known that I, JAMEs M. liroinxiuisox, a citizen of the United. States` and residing at Highland Park, in the county of yayne and State of Michigan, have invented a new and Improved Headlight, of which the fol? lowing is a specification.

In my United States Patent No. 1,088,094, February 24, 1914, there is disclosed and claimed a headlight for motor vehicles comprising a main filament positioned substan tially in the focal center of a reflector together with an auxiliary filament spaced somewhat therefrom and electric circuits whereby the auxiliary filament may be heated independently of the main filament at will: when the main filament is heated. a strong search light suitable for country driving is secured, but when current is passed through the auxiliary filament the light is thrown down upon the roadway to provide a desirable light for street or city use. Due to imperfections incident to the manufacture of the reflector, as well as to other causes, a slight amount of glare, which it is the object of the present invention to eliminate, has been experienced upon heating the auxiliary filament.

This I do by coating, frosting, coloring or otherwise treating the front end portion of the bulb in such manner as to intercept those direct rays from the auxiliary filament which would otherwise strike the reflector and be thrown upwardly into the eyes of an observer standing in the street, while nevertheless limiting such treatment so that the rays incident on the rear portion of the reflecting surface will be reflected forwardly without interference. Thus, when the main filament is heated the rays therefrom are directed forwardly in substantially parallel beams, while when the'auxiliary filament is heated its reflected rays sweep forwardly and downwardly over the road to provide a satisfactory illumination without tending to blind an approaching pedestrian or driver. In other words, I screen out those rays which have given rise to glare and retain those primarily effective for illuminating purposes. Although this effect may be attained in -various ways, l prefer to render the forward portion of the bulb merely translucent, as distinguished from opaque, since the more direct rays are thus made use of to light up the road at the sides and close to the lamp; this may be readily done by dipping the front end of the bulb iu some suitable mixture or variety of white paint.

The extent of the coating or treatment depends somewhat on the size of the bulb and of the reflector, as well as on the position of the auxiliary filament with reference to the focal center, but to secure the most satisfactory results it should extend back substantially to the vertical plane through the focal center of the reflector when the bulb is propcrly adjusted therein, or a little further: however. substantial improvements over prior practice may be had even when the treated areav terminates forwardly of this plane. The area to be treated is most readil \v determined by experiment with each type of lamp and bulb.

In the drawings, Fig. 1 is a section showing a preferred embodiment of the invention. Fig. 2 is an enlarged side View of the bulb in position in its socket. Fig. 3 is a view on line 3 3 of Fig. 2. Fig. 4 is a diagram showing the path of rays emanating from the auxiliary filament.

1 indicates an ordinary headlight body carrying the usual lens ring 2, lens 3 and reflector 4 (preferably parabolic) wherein is mounted a lamp socket 5. The latter is electrically grounded to the reflector and is equipped with a bulb 6 having a main filament 7 located substantially in the focal center of the reflector; this bulb also has an auxiliary film 8 preferably positioned above the main filament and substantially in the vertic-al4 transverse plane which passes through the focal center. shown in my patent above referred to wherein the relation of the two filaments is different from that here shown, might be employed, but I prefer the present construction. inasmuch as it provides a proper concentration of light and a sturdy support. particularly for the auxiliary filament. lt will be understood that when the switch 10 is thrown to engage the contact 11 current from the battery or other source 12 passes through the main filament 7, and that when the switch is in engagement with the contact 13 current passes through the auxiliary filament 8; and the rays fromv the former will evidently pass forward from the rear portion of the reflector in substantially parallel relation one to another,

Other bulbs, such as those as is usual in such headlights, it being observed, however, that thoserays which are interceptedi by the treated area of the bulb are diffused downwardly and laterally over the road as heretofore stated.

With reference to the auxiliary filament the action will be best understood from Fig. 4, and as indicated therein, all rays 16 emanating therefrom and striking the refiector rearwardly from the transversevertical plane 17 through the focal center are refiected downwardly, whereas all rays 18 striking the reflector forwardly of said plane pass upwardly and would'theoretically tend to cause glare or blinding when observed by a pedestrian or by the driver of an approaching vehicle. The treated area 15, screening out the rays 18, insures the presence of the downwardly projected primary reflected rays 16 only, but when the treatment is such as to render the glass translucent merely, the rays 18 are diused downwardly and llaterall over the roadway als stated above with refl erenceto the main filament. It is obvious that the screen or treated area need not necessarily be formed directly on the bulb itself, but l prefer the form shown on account of its cheapness and other desirable characteristics.

1. A vehicle head light comprising a rev flector having a focal center, a bulb havingy two filaments, the first of which is locate approximately at the focal center and the second a distance from the first but in approximately the same vertical plane, said bulb being frosted over its front surface and back sufficiently far 'to diffuse all direct rays visible from the front and all reected rays except enough to mak'e a small central concentrated beam of light.

2. A vehicle head light comprising a reflector having a focal center, a bulb having two filaments, the first of which is located approximately at the focal center and the second a short distance above the first, means whereby said filaments may be separately illuminated, said bulb being frosted over its front surface and back rsufficiently far to diffuse all direct rays visible from the front and all reflected rays except enough to make a small central concentrated beam of light whichever filament is illuminated.

JAMES M. RICHARDSON.

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