US 1601293 A
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Description (OCR text may contain errors)
Sept 28 1926.
J. CATHRILL LAMP Filed July 5 1923 horizontally from the lam Patented Sept. 28, 1926.
UNITED I STATES PATENT OFFICE.
JACK current, or LOS ANGELES, CALIFORNIA.
Application filed ui e, 1923. Serial no. 649,508.
This invention relates to a lamp and par v An object of my invention is'to provide a lamp in which the light rays emanating therefrom are directed in such fashion that a when the lamp is positioned to direct a beam light horizontally, such rays as would normally diverge upwardly above the horizontal will be directed downwardly thereby obviating the blinding effect caused by the upwardly diverging rays.
Another object is to provide a head lamp in which a beam light may be projected lightemanating from the amp below or to one side of an axial plane extending -through a lighting element in the lamp, and
embodying means for intensifying a portion of the beam light.
With the foregoing objects in view, together' with such other objects as may later appear, my invention resides in the parts and in the construction, arrangement and combination of parts hereinafter described and claimed and illustrated byway of example in the accompanying drawings, in which Fig. 1 is a perspective view of a lamp constructed in accordance with the invention. I
Fig. 2 is a view of the lamp as seenin longitudinal section.
Fig. 3 is a diagram illustrating the manner of directing and projecting light rays or beams by means'of cooperating reflectors or mirrors,'showing the manner of intensifying the beani light.
v Fig. 4 is a detail in perspective of a reflector visor forming part of the lamp.
Fig. 5' is a perspectiveview illustrating another form of ;the reflector visor.-
' More specifically, 7 indicates a lamp hous- Whichaxis is indicated bythe dotted lines with the beam parabolic form as is common in ordi- 1111 in Fig. 3, and which, for the purpose I of explanation, will be assumed to extend on .a horizontal plane.
In carrying out my invention I employ a visor 12 which is in the'form of a segment of a sphere, the visor having a form approximately a quarter of a sphere. This visor is arranged in front of the reflector 8 and extends over the portionof the latter projecting above the horizontal axis 11-11 so that the visor will act as a'shield against upwardly projecting rays. The inner con cave surface of the visor is of reflective' character, thus forming aspherical mirror comprising a segment of a spherlcal surface.
The visor'in extending .over the upper open portion or aperture of the parabolic reflector, the outlet for the light from the light element 10 is confined to the portion of the lamp below the axial line 1111; the light rays reflected by the lower portion of' the parabolic reflector being directed substantially parallel through approximately onehalf the area of the aperture of the parabolic reflector, th us forming a beam light in which the major portion of the rays will extend parallel to each other in the direction of the axial li-ne 11--11, as indicated by the dotted lines a--a-in Fig. 3.
In order to accomplish the intensifying of the beam light a-aand to effect the desired spread of a flood light, the concave reflective surface on the inner face of the visor 12 is formed on the segment of a spherical surface, the center of curvature of which is located above and spaced from the horizontal principal axis of the parabolic reflector, as indicatedat 13.- This center of curvature is also located preferably on the plane of the outer end of the parabolic reflector.
The visor. 12 is formed with its lower marginal portion extending on a plane be low and spaced from the axial line 11-11 of the parabolic reflector, thus providing a mirror 15 in the form of a segment of; a spherical surface extendingbelow the source of light 10.
The visor may be of any suitable construction and may be attached to the lamp housing 7 in any desired manner. For example. the visor may be formed of'a ring 16, as shown in Fig. 5, which ring is adapted to encircle the margin of the parabolic reflector, as shown in Fig. 2; the ring 16 bein attached to the housing 7 in any desired manner and serving to hold the glass plate 17 in position over the parabolic reflee-tor, as is common in head lamp construction. In some instances, however, the; visor 12 mav be formed with a flange 18 as shown in Fig. 4, by which it may be engaged with the front of the lamp housing in any desired manner. 7
The concave spherical reflective surface interiorly of the visor 12 may be formed in any desired manner, as by forming the visor of metal which may be polished, nickled, or coated with any suitable reflective material. in some instances a silvered mirror formed of glass may be disposed within the interior of the visor. I therefore do not limit myself to any specific construction of the visor. or the manner of mounting same; the essence of the invention residing in providing a reflector or mirror in the form of a segment of a spherical surface arranged forward of the parabolic reflector in such fashion as to. cooperate with the latter in directing light rays as hereinafter described.
In the operation of the invention, it is to be noted that the rays or beams of light from the light element directed against the parabolic: reflector will be projected substantially parallel from the latter, as is well known in the operation of parabolic reflectors in headlights, searchlights, and the like. against the upper portion of the parabolic reflector directly from the light element 10,
' as indicated on broken line 6-?) on Fig. 3,
are projected horizontally and substantially parallel, as indicated by the broken lines c0 against the concave reflective surface of the spherical mirror, and are thence projected downwardly and divergently as indicated by the broken lines (Z-d to form what is termed a flood light. The upwardly diverging rays from the light element 10, passing through the aperture of the parabolic reflector, as indicated by the broken lines ee and are intercepted by the reflective surface of the spherical mirror and in the case of the uppermost rays are directed downwardly in front of the parabolic mirror as indicated by the dotted lines f, and in the easeof the lowermost rays 6 are reflected rearwardly into the parabolic reflector and re-retlei ted thereby as indicated by the broken lines g h and 2' back on to the spherical mirror and thence refle ted downwardly as indicated by the broken line 7'. It will thus be seen that all of the rays or beams projecting upwardly from the light element 10 above the axis of the parabolic The light rays projected reflector will be finally emitted from the lamp in a downward direction.
A beam is of light projecting from the light element 10 immediately below the axis 1111, is projected against the portion 15 of the spherical mirror extending below the plane of the axis 11-11, and is thence projected upwardly and rearwardly against the parabolic reflector as indicated by the heavy dotted lines. and are then directed downwardly against the lower portion of the parabolic reflect-or so as to be finally'projected from the lamp through a focal point Z, from whence the rays of the beam diverge among the substantially parallel rays wa of the beam light thus intensifying the beam light. The portion of the visor 12, extendingbelow the plane of the axis 11, serves as a shield to obscure the source of light from view from a point on a plane forward of the lamp extending on the axis 1111 thereof, thereby obviating the blinding of:
fe:t of the horizontal rays; but, the rays or concave reflector extending in front of theopening of said parabolic reflect-or throughoutthe area above the plane of the axis thereof and having a straight lower margin. extending throughout on a horizontal plane being below the axis of the parabolic re-' tlectonsaid concave reflector having its entire reflective surface conforming to the segment of a sphere the curvature of which is struck from a center located above the axis of said parabolic reflector.
' 2. In a lamp, a substantially parabolic reflector, a source of light therein, and a reflector-visor extending in front of the opening of said parabolic reflector having a lower marginal portion extending below the plane of the axis of said parabolic reflector ill mil
llllil said visor being curved both horizontally and vertically on arcs struck from a center located above the axis of the parabolic reflector. V
' JACK CATHRHAL.