US1992823A - Lamp - Google Patents

Description

, 1935- s. GREENMUN 1,992,823

LAMP

} Filed April 8, 1933 INV EN TOR.

ATTORNE Patented Feb. 26, 1935 UNITED STATES 2 Claims.

The present invention relating as indicated to lamps, is more particularly directed to a new and improved lamp of the type used on motor cars for illuminating the roadway although, as will be evident from the following description, my improvements may be employed in lamps for numerous other purposes. The principal object of the invention is the provision of a lamp in which all the light issuing from the lamp will be reflected light, controlled and directed in certain predetermined beams without permitting observation of the source of light from the outside of the lamp.

To the accomplishment of the foregoing and related ends, said inventionthen, consists of the means hereinafter fully described and particularly pointed out in the claims; the annexed drawing and the following description setting forth in detail one product exemplifying my invention, such disclosed product constituting, however, but one of various applications of the principles of my invention.

In said annexed drawing:

Fig. 1 is a front elevation of my improved lamp with the casing omitted; Fig. 2 is a section on the line 2-2, Fig. 3; Fig. 3 is a vertical central section through the lamp; and Fig. 4 isa plan view illustrating the beams produced by my improved lamps and the relation between the two in use on the ordinary car.

Referring now to Figs. 1, 2 and 3, there is shown a lamp comprising an outer casing or shell 1 and a lamp socket 2 provided with an internal sleeve 3, within which is received a terminal 4, leading to any suitable source of current and against which is mounted the terminal end 5 of the bulb 6. The lamp further includesa rear reflector 7 secured to the socket and disposed within the casing 1, and a forward reflector 8 disposed in front of the bulb. The rear reflector has a portion 9 which extends over the bulb and to a point in front of the bulb, being provided with a horizontal supporting flange 10 which extends to the forward edge 11 of the shell 1. The forward reflector 8 is in eflect a continuation of the portion 9 of the rear reflector and is provided with a horizontal flange 12, similar to flange l and also extending to the forward edge 11 of the shell.

For convenience'in assembling and removing the bulb 6, the forward reflector is pivoted at one end of the shell about a pin 13, while the other end is snapped into a clip 14 when in position.

The present improvements relate essentially to the construction and disposition of the reflectors and the bulb, and it will be seen that the reflector 8 extends to such a point that no rays emanating directly from the filament of the bulb are permitted to pass directly out of the casing, as is indicated by the dotted line 15 running from the center of the bulb filament past the lower, edge 16 of reflector 8, and terminating inside of the reflector 7. The reflector 8 is so formed that the rays striking it from the bulb are reflected to the reflector 7, from which they are then in turn reflected, all of the reflected rays from both reflectors issuing as a beam of light which is substantially horizontal along its upper boundary and which extends as a fan-like beam from a horizontal position downwardly for illumination of the road.

The reflectors are also formed in the manner indicated in. Figs. 1 and 2 so that the reflected light rays forma divergent beam, as shown in Fig. 4. The divergence is not sharp and a relatively broad beam is thrown forwardly in such a position as to merge with the beam from the other of the two headlights which are ordinarily used to illumine the full width of the roadway and areas on either side thereof sufficient to include ditches, curbs and the like.

While the construction and relation of the bulb and reflectors constitute the important feature of my improvement, this construction makes'it possible to eliminate the ordinary thick and 'ex-' pensive lenses and I am able to employ ordinary glass 27 in the front of the lamp shown in Fig. 3, this glass being mounted at an angle to the vertical and being entirely plain since the reflectors accomplish all that is usually accomplished by the lens and produce properly directed beams without assistance from the glass.

I have found from repeated tests with lamps embodying my invention that it is impossible to produce a glare even when bulbs of the ordinary candle power are used, while a full illumination of the roadway can be secured, the illumination being confined to such a height that is does not reach the eyes of oncoming drivers or pedestrians.-

The cost of my improved lamp is materially re- 5 duced by the elimination of the heavy, expensive lenses which are now universally employed to direct the light rays into the desired paths. Such lenses are of course unnecessary in my construction, in which all of the rays are directed in the proper paths by the reflecting surfaces.

Other forms may be employed embodying the features of my invention instead of the one herein explained, change being made in the form of construction, provided the elements stated by any'of the following claims or the equivalent of such stated elements be employed.

I therefore particularly point out and distinctly claim as my invention:-

1. In a lamp, a source'of light, and a reflector disposed about said source of light and substantially concealing said source of light from view from without said lamp, said reflector consisting of two pivotally connected parts, one of which has alower portion of substantially parabolic cross-section and an upper portion of substantially circular cross-section extending in front of said bulb to a horizontal plane passing through said light source, and the other part of said reflector being of circular cross-section and extending to a plane below said source of light.

2. In a lamp, a casing, a source of light within said casing, a reflector disposed about said source of light and substantially concealing said source of light from view from Without said casing, said reflector consisting of two parts, one of said parts having a lower portion of substantially parabolic cross-section and an upper portion extending over said bulb and provided with a horizontally extending flange secured to said casing, and said other part extending from said first part to a point below said source of light and provided with a horizontally extending flange, and means for pivotally securing said flanges to each other.

LEO S. GREENMUN.

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