US1319823A - Headlight - Google Patents

Description

0. WINSTON.

HEADLIGHT.

APPLICATION FILED FEB. 19.1912.

1,319,823. Patented 0m. 28,1919.

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HEADLIGHT.

APPLICATION FILED FEB. 19, 1917 1 3 1 9,823 Patented Oct. 28, 1919.-

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HEADLIGHT.

APPLICATION FILED FEB. 19, I91].

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HEADLIGHT.

APPLICATlQN FILED FEB. 19. 1912.

1,319,823. Patent-ed Oct. 28,1919.

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HEADLIGHT. APPLICATION FILED FEB. 19,1917.

Patented Oct. 28, 1919.

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HEADLIGHT.

Specification of Letters Patent.

Patented Oct. 28, 1919.

Application filed February 19, 1917. Serial No. 149,471.

To all whom it may concern:

Be it known that I, OVERTON WINSTON, a citizen of the United States, residing at Minneapolis, in the county of Hennepin and State of Minnesota, have invented certain I new a'nd useful Improvements in Headlights; and I do'hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My present invention relates to headlights and is particularly directed to an improved form of lens and to an improved relative arrangement thereof, in respect to a concave reflector and an electric light bulb within the latter. The present invention is in the na ture of a modification of, or improvement on the construction disclosed and more broadly claimed in' my companion application S. N. 149,392, filed of date February 19, 1917, and entitled Headlights.

The invention is illustrated in the accompanying drawings, wherein like characters indicate like views. Referring to the drawings;

Figure 1 is a vertical section showing a headlight embodying my invention, and wherein a two-filament li 'ht bulb is employed as a means for shifting a light source from the axis of the reflector to a point vertically above said axis;

Fig. 2 is an elevation looking at the inner face of the lens;

Fig. 3 is .an enlarged fragmentary section on the line 3--3of Fig. 2;

Fig. 1 is an enlarged fragmentary view in inner face elevation, showing a segmental portion of the lens;

Fig. 5 is a longitudinal section taken approximately on the line 55 of Figs. 2 and 4;

Figs. 6, 7, 8, 9, 10 and 11 are fragmentary sections taken on the lines 6-6, 77, 88, 9-9, 1010 and 11 11 of Fig. 4.

Fig. 8 is an enlarged section of the prismatic segments shown in Fig. 8;

.Fig. 12 is'a view corresponding to 1,

but showing the headlight having a single filament light bulb;

Fig. 13 is an inner face elevation sh0wing a lens of slightly modified construction;

Fig. 13 is an enlarged section on the line 1313 of Fig. 13;

Fig. 14 is an enlarged fragmentary view arts throughout the several in inner face elevation showing a segmental portion or the lens;

Fig. 15 is a section on the line 15-15 of- Fig. 14;

F s. 16, 17, 1 8, 19 and 20 are sectionstaken, respectively, on the lines 16-16,

1717, 1818, 19-19 and 20-2O of Fig.

14; and

Fig. 20 is an enlarged section of prismati segments shown in Fig.'20.

Of the parts of the headlight, the numeral 21 indicates the casing, the numeral 22 the clamping ring thereof, the numeral 23 the concave reflector, the numeral 24 the electric light bulb, and the numeral 25 the lens. The reflector 23 is preferably a hyperbolic reflector and it is provided with an axial passage through which the shank of the bulb 24 projects and is held by a suitable support. This bulb support, so far as this invention is concerned, may be of any suitable construction, but as shown, comprises a shank engaging sleeve 26 and a tubular.

socket body 27 screwed into a flanged hub 28 secured on the back of the reflector.

The bulb shown in Fig. 1 is a two-filament bulb, the one filament having its hot spot at a and the other having its hot spot at b. The point a is at the axis of the reflector and preferably also at the focal center thereof. The point 6 is vertically above the axisof the reflector. By means of a three-lead circuit 29, 30 and 31, which includes a'battery 32 and switches 33 and 34, either of the two filaments a or b, may, at will, be energized and used as the light source of the headlight. These electrical connections are more fully disclosed in my pending application S. N. 86,852, filed of date February 27, 1916, and entitled, Headlights.

In Fig. 12, the light bulb 16 is provided with a single filament c, the hot spot of which is at the axis of the reflector and preferably also at the focal center thereof. This filament is connected to a battery or source of electrical energy 35 by leads 36 in any one of which is a switch 37.

' We will now consider the novel construction of the lens, the preferred form of which is illustrated in the drawings and which is described, is as follows:

One face, preferably the inner face of the lens is formed with radial prismatic seg* ments of peculiar form. These prisms radi ate from the center of the lens, or from the axis of the reflector and have their greatest bevel nearest to the axis. For example, assume that the bevel surface of any particular prismatic section has an angle of'zero, or is parallel to the plane or basal surface of the lens at its outer extremity, and that is generated by a line that increases its angle constantly as it moves toward the axis. This, however, gives a peculiar form of prismatic segment which because of the varying angle, and contracting width of the segment, produces the greatest thickness in the segment at points approximately midway between the axis and rim of the reflector. erably have an angle of approximately zero at their outer extremities, but they vary in their angle at their inner extremities. In thepreferred arrangement, the maximum angles of the prismatic sections in directions circumferentially from the upper vertical line, increase progressively to the horizontal and decrease in reverse order from the hori zontal to the lower vertical line. For example, they may be, and preferably are, as indicated by the small numerals marked adjacent to their outer extremities on Fig. 2. These numerals indicate the maximum angle or the angle at the inner extremities and not those at the outer extremities.

As already indicated, the beveled surfaces of the prismatic segments that are on opposite sides of the upper vertical line of the lens, incline or bevel in reverse directions,-

so that they increase the thickness of the prisms in both directions, circumferentially from the said upper line. This direction of the bevel is important because it causes the rays that leave the face of the lens to be given a material downward deflection, or, in other words, projection below the axial radial planes of boththe reflected and direct rays. The effect of this is to produce a general downward deflection of the light beam so that a very much greater part thereof will reach the ground than with any lens known to me. Moreover, it is the rays of beams that ordinarily are projected upward and which produce blinding efl'ects, but do not light the road, that are thus most deflected or refracted, and turned downward onto the road. This arrangement also permits a still further improved light effect. Moreover, it is the rays that are most nearly to a horizontal that are given the greatest downward deflection. The exact manner in which the segmental prisms are distributed may be varied but are preferably as illustrated in the drawings and above described in detail.

With the two filament light bulb or shifting light source shown in Fig. 1, there will be the above noted downward deflection of the beam when the light source is at point a but this downward deflection .will be materially increased when the light source is All of the segmental prisms pref' neraeas shifted from a to 72. Hence, the shifting light source, in combination with a lens, such as described, makes possible a light beam of long projection, but with a maximum amount of light on the road and a min imum amount of light above the road.

An ideal beam for headlights for city street driving is, as already indicated, produced when the light source is at the vertically oflset point 6.

In the use of a headlight with an ordinary reflector adjusted so as to throw approxi mately the lower half of the light beam upon the ground, which is a quite common arrangement, the lower half of the light beam will be distributed over many hundreds of square feet of road surface, and per unit ofsurface, the road will be given but a very small percentage of light, as compared with the amount of light thrown upon a vertical object in the road, by the upper half of the light beam.' This is a result just reverse from that desired.

An ideal arrangement would be one in which there would be atleast as much light per unit of surface thrown upon the'foad as there would upon a vertical object above the road; and such an arrangement, obviously, requires very much the greater part of the light beam to be distributed on the ground and a very minor part of the light beam to be diffused above the road. This ideal result is closely approximated by the use of the improved lens above described, which, as already stated, produces very great downward deflection of the more intense rays of the light beam and difl'uses some or a minor pars?i of the less intense light rays above the roa In the modified form of the lens shown in Figs. 13 to 20, inclusive, the prismatic segments do not cover the entire face of the lens, and, as shown, are in circumferential disposition, much like the arrangement illustrated in the drawings of my application, S. N. 149,392, filed of date February 19, 1917, and entitled Headlights.

In this modified form of the lens, however, the beveled surfaces of the prismatic segments, instead of starting from zero at the rim of the lens, start with a bevel that is approximately one-half the maximum bevel and progressively increases in bevel inward toward the center of the lens. For example, the two uppermost prismatic segments which bevel in reverse directions, may have one degree bevel at the rim of the lens and increase to two degrees, approximately at the center of the lens. Likewise, the horizontal segmental prisms may start with 22 degrees at the rim or outer portion and increase to 44 degrees, approximately at the center of the lens.

What I claim is:

l. A lens for headlights having a group of diverging prisms beveled in the same general direction and having increasing angles to the basal surface of the lens, progressively in a direction circumferentially from the upper portion toward the horizontal diameter of said lens, the individual prisms, in themselves, in a direction inward from the rim of said lens having increasing angles to the basal surface of the lens.

2. lens for headlights having two groups of prisms disposed on opposite sides of its vertical diameter, the prisms in the same group being beveled in the samegeneral direction and the prisms of the difi'erent groups being beveled in opposite directions, the individual prisms, in themselves, in a direction inward from the rim of said lens, having varying angles to the basal surface of the lens.

3. A lens for headlights having a group of diver ing prisms with major retracting surfaces beveled in the same general direction and which prisms, among themselves, having increasing angles to the basal surface of the lens in a direction circumferentially from the vertical toward the horizontal diameter of said lens, the individual prisms, in themselves, in a direction inward from the rim of said lens having. varying angles to the basal surface of the lens.

l. A lens for headlights having two groups of prisms disposed on opposite sides of its vertical diameter, the prisms in the same group being beveled in the same general direction, and among themselves, having progressively increasing angles to the basal surface of the lens, in a direction circmrnferentially from the vertical diameter toward the horizontal diameter of the lens the individual prisms, in themselves, in' a direction inward from the rim of the lens, having progressively increasing angles to the basal surface of the lens.

in testimony whereof l afin my signature in presence of two witnesses.

@VERTON WINSTON.

Witnesses:

CLARA DnMARns'r, BERNICE G. Wnnn ma.

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