US1614027A - Lamp - Google Patents

Description

Jan. 11, 1927. 3,614,027 R. GRAF LAMP Filed July 1 I 1925 Patented Jan. 11, 1927.

UNITED STATES PATENT OFFICE.

RICHARD GBAF, OF SOUTH BEND, INDIANA.

LAMP.

Application filed July 1, 1925. Serial No. 40,782.

My invention relates to headlamps such as are used on automobiles.

The main object of the invention resides in the provision of a lamp which while projecting an adequate and eflicient light so controls the light as to prevent glare in the eyes of occupants of other vehicles or pedeserence to'the accompanying drawings and more particularly pointed out in the appended claims;

In the said drawing Figure 1 is a central vertical longitudinal section of a lamp embodying my invention.

Figure 2 is a rear elevation of the light shield of the lamp.

Like characters of reference indicate like parts in the various views.

Referring to the drawing 1 designates a m in cylindrical casing member upon the re r end of which is screwthreaded a deep bell shaped rear casing member 2 completing the casing. A deep forwardly facing cup reflector 3, preferably elliptical asshown, is positioned rearwardly iii the casing and is provided with a forwardly facing electric lamp socket mounting 4. disposed on the focal axis of the reflector, in which is mounted for longitudinal adjustment along said focal axis a usual electric lamp socket 5.

The adjustment of this socket is controlled from the exterior of the lamp casing by a usual adjusting means 6. A usual incandescent electric lamp 7 within the reflector is mounted in the socket 5. The reflector has an inner and outer focus, and the electric lamp is adjusted to the inner focus thereof. A condensing lens 8 is disposed at the forward end of the casing co-axial with the reflector to project the light from the electric lamp and reflector and is mounted on the casing by a ring 9 screwthreaded on the front end of the casing member 1 and clamping the margin of the lens between it and an internal flange 10 of the casing member 1. The rear focus of the lens is disposed substantially at the outer focus of the reflector in order to project the concentrated reflected light together with the direct light from the electric lamp.

An opaque light shield 11 surrounding the focal axis of the lamp is disposed Within the casing 1 and has a relatively small centrally disposed aperture 12 substantially at the rear focus of the lens. From this aperture the shield extends and enlarges rearwardly with an interior generally frusto-conical reflecting surface 13 coaxial with the reflector and lens to the lip of the reflector. The reflector and shield are provided with exterior circumferential flanges, designated at 14,which are clamped in superposed relation between interior shoulders 15 when the casing members are assembled. the flange 14 of the shield carrying rearwardly projecting pins 16 engaging in apertures of the flange 14 of the reflector and shoulder 15 of the casing member 2 to angularly position the casing member 2, the reflector and the shield when assembled.

The aperture 12 being disposed substantially at the inner focus of the lens causes a real image thereof to be projected by the lens and by reason ,of this position of the aperture and the relatively small size of the same a relatively small sharply defined beam of intense light from the electric lamp and reflector is projected by the lens.

The aperture 12 as shown is elongated horizontally, see particularly Fig. 2, Whereb the light is shielded to a greater degree a ove and below the focal axis of the lamp than at the sides thereof, and the lower edge portion of the aperture is disposed nearer the focal axis of the lamp than the upper edge portion thereof whereby the light is shielded to a greater degree below the focal axis of the lamp than above the same, it being obvious that a reverse image of the aperture is projected by the lens.

The above referred to beam of intense light has a cross section of the aperture 12 reversed, and the upper portion thereof is substantially parallel with the focal axis of the lamp whereas the sides diverge to a maximum degree a'nd the lower portion of the beam divergesj't'o an intermediate degree. As a result the road'in front of a vehicle equipped with the lamp is illuminated from side to side from a point adjacent the lamp forwardly though the intense beam does not extend upwardly far enough to lare in the eyes of occupants of other VQlllClGS or pedestrians.

The shield 1.1 has chordal interior reflecting surfaces 17 extending rearwardly and outwardly from the upper and lower portions of the aperture 12 and merging with the generally frusto-conical interior reflecting surface 13 of the shield whereby the upper and lower edge portions of the aperture together with the side edge portions thereof are disposed in a common plane thoughthe rearward and outward extension of the interior surface of the reflector is maintained throughout.

The interior reflecting surfaces 13 and 17 of the shield 11 serve not only to reflect light indirectly back to the reflector but to reflect dispersed light from theelectric lamp and the reflector directly to the lens from which this light is projected as a dispersed nonglaring light about the aforementioned intense beam to further aid in the illumination adjacent the lamp. In addition the light reflected from the reflecting surfaces 13 and 17 serves to increase the brilliancy of the light image at the aperture 12 with resulting increase in the brilliancy of the aforementioned intense beam.

Thus it will be observed that the light is conserved and projected so that it is applied to the best advantage without glare and with consequent efficiency and adequacy of light.

While I have herein shown and particularly described the preferred embodiment of my invention I do not wish to be limited to the precise details of construction shown as changes may readily be made without departing from the spirit of my invention, but having thus described my invention I claim as new and desire to secure by Letters Patent the following:

1. In a lamp of the character described the combination with a casing open at. its front end, a forwardly facing cup reflector having an inner and an outer focus and mounted rearwardly in the casing with its outer focus within the casing, an incandescent electric lamp at the inner focus of the menace? reflector, and a condensing lens mounted forwardly on the casing and positioned to pro ject the light from said reflector and elec tric lamp with its rear focus substantially at the outer focus of the reflector, of an opaque light shield surrounding the focal axis of the lamp between said lens and said reflector and electric lamp and having a relatively small centrally disposed horizontally elongated aperture substantially at the rear focus of the lens and having its lower edge portion disposed nearer the focal axis of the lens than the upper edge portion thereof, and extending and enlarging reap wardly therefrom with an interior generally frusto-conical reflecting surface to the lip of the reflector and having chordal interior reflectingsurfaces extending rearwardly and outwardly from the upper and lower poitions of said aperture and merging with said frusto-conical surface.

2. In a lamp of the character described, the combination of a casing open at its front end, a forwardly facing cup reflector, an incandescent electric lamp located in the axis of the reflector so as to have its rays converged by said reflector at a point on said axis and forwardly thereof, a condensing lens mounted forwardl on the casing with its rear focus substantially at the point of convergence of the rays, of an opaque light shield surrounding the focal axis of the lamp between said lens and said reflector and electric lamp, and having a relatively small centrally disposed horizontally elongated aperture substantially at the rear focus of the lens, and having its lower edare portion horizontal and disposed nearer the focal axis of the lens than its upper curved edge portion, and extending and enlarging rearwardly therefrom, with an interior generally frusto-conical reflecting surface to the.

lip of the reflector.

In witnes whereof I hereunto alhx my signature this 23rd day of June, 1925.

RICHARD GRAF.

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