US 3739169 A
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United States Patent 1 Weinreich 1 June 12, 1973 PANORAMIC LIGHT EMITTER FOR WARNING LIGHTS  Inventor: Wilhelm Weinreich, 354
Friedrichstrasse 30, Kurbach, Germany 22 Filed: Aug. 30, 1971 211 App]. No.: 175,977
 Foreign Application Priority Data Sept. 1, 1970 Germany P20 43 253.5 Dec. 23, 1970 Germany P 20 63 481.5
 U.S. Cl. 240/22, 240/4l.3, 240/4l.35,
240/93, 240/106.1  Int. Cl. F211 15/02  Field of Search 240/22, 7.5, 41.3,
 References Cited UNITED STATES PATENTS 3,654,451 4/1972 Starr 240/4l.35 R 2,344,221 3/1944 Trautner 240/22 1,589,370 6/1926 Conover 240/l06.1 3,253,276 5/1966 Nagel 240/106.l 3,383,676 5/1968 Nagel 240/l06.1 2,586,374 2/1952 Pennow 240/22 X 1,033,782 7/1912 Churchill 240/l06.1 1,495,521 5/1924 Kopp 240/106.l 1,944,154 l/l934 Dickson 240/l06.l 2,003,804 6/1935 Falge 240/l06.l
Primary ExaminerSamuel S. Matthews Assistant Examiner-Richard M. Sheer AttorneyStanley J. Price, Jr.
[5 7] ABSTRACT The panoramic light emitter includes a cylindrically shaped converging lens positioned around a central light source. The lens directs the rays of light passing therethrough in a horizontal direction generally perpendicular to the vertical axis of the emitter. Concave reflectors having a configuration in section of segments of a parabola are positioned above and below the cylindrical lens. The light rays strike the reflectors and reflect horizontally parallel to the light rays reflected by the lens so that substantially all of the light from the light source is either deflected by the lens horizontally or reflected by the reflectors horizontally to provide a panoramic source of light for 360 degrees around the vertical axis of the emitter. Another embodiment has a transparent generally cylindrical member positioned over the light source with the axis of the cylindrical member coaxial with the vertical axis of the emitter. The cylindrical member has upper and lower portions positioned above and below the light source that deflect the vertically projected rays of light emanating from the light source to a horizontal direction generally perpendicular to the vertical axis of the emitter. The intermediate portion of the cylindrical member has an annular cylindrical concave lens and annular upper and lower deflectors that also project the intermediate portion of the light generated by the light source in a horizontal direction to thus provide a panoramic source of light for 360 around the vertical axis of the light emitter.
5 Claims, 4 Drawing Figures PATENTE JUN a 2 mm SHEET m Q M3 Wm;
PANORAMIC LIGHT EMITTER FOR WARNING LIGHTS BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a light emitter and more particularly to a light emitter that directs substantially all of the light generated by a light source in a horizontal direction.
2. Description of the Prior Art Light emitters for warning lights are known. For example, warning lights rotated on the roof of a vehicle have light emitters that include reflectors positioned above and below the light source. The reflectors are connected to a drive motor so that they rotate during operation of the warning light. The reflectors are spaced or gapped at a predetermined angle to obtain the desired warning lighting effect during rotation. With this type oflight emitter a motor is required to rotate the reflectors and less than all of the light emanating from the light source is emitted from the device because of the cylindrical shape of the reflectors. Another type of emitter is known which includes a drive motor to drive two converging lens with which a flashing type warning effect is achieved. This type of emitter also requires a separate drive motor and does not utilize all of the light generated by the light source.
Warning light emitters are also known that do not require a separate drive motor. For example, an emitter is known that includes a circular drum lens with toric surfaces. The toric surfaces break up the light rays as they emerge from the center of the drum lens and direct the light rays at substantially right angles to the vertical optical axis of the lens. Another beacon type emitter is known where a source of light is surrounded by a converging or drum lens so that rays are projected around the beacon for 360. Neither of the above stationary emitters utilize and emit all of the light generated by the light source. There is a need, therefore, for a light emitter that improves the utilization of the light energy generated.
SUMMARY OF THE INVENTION The panoramic light emitter, according to the invention, provides for the light to be radiated over an angle of 360 and includes a converging lens positioned on the same horizontal level as the light source and extending over 360. At least one reflector is positioned above the light source and has a concave reflecting surface operable to deflect light over 360 in relation to the vertical axis of the light source. The reflector is sta-- tionary and arranged to deflect light emerging from the light source in a horizontal path.
If a warning effect is required from the light source, this can be achieved by operating the light source intermittently. Continuous operation of the light source is, of course, possible. The panoramic light emitter of the invention is therefore particularly suitable for use on sites where the only energy source generally available comprises either batteries or accumulators whose energy must be utilized in the best possible way.
Utilization of the energy from the energy source is further improved if reflectors are positioned both above and below the light source. It is preferable to form the profile of the reflectors by the rotation of one or more elliptical curves, such as a parabola, in such a manner that the reflected light rays strike the wall of the casing either radially to its central axis or at an angle thereto, depending upon the nature of the curves. In the preferred embodiments the axial height of the converging lens is substantially equal to the shortest distance between the reflectors positioned above and below the light source.
The outside diameter of the converging lens is preferably so selected that the light rays which do not strike the reflectors and the converging lens strike the upper and lower edges of the wall of the casing. These latter light rays are tangential to the upper and lower edges of the converging lens. This arrangement assures that all of the light rays are directed to the wall of the casing either through the converging lens or through the reflectors and further that no diffusion of the light rays occurs to the converging lens and reflectors. The lower parabolically-shaped reflectors can be provided with a central bore through which extends a support for the light source. The converging lens may also be connected through a plurality of struts to the upper parabolically-curved reflector. Where desired, it is possible to obtain a preselected degree of scatter in the emerging light rays by providing lenticular rings or curved portions on the inner or outer surface of the casing walls. The lenticular rings or curved portions disperse the light rays that strike the wall of the casing at right angles or at substantially right angles. The dispersion of the light rays compensates for the deviation from a precisely vertical suspension of the panoramic light emitters.
For the purpose of further reducing manufacturing costs, the converging lens may form the substantially perpendicular portion of the casing and the optical refractors above and below the light source and converging lens may constitute a portion of the casing. The reflectors may be composed of prismatically profiled individual elements which are offset from each other and reflect the light rays striking them. In this arrangement, one reflector is provided by a portion that tapers upwardly away from the light source and the other reflector by a portion that tapers downwardly away from the light source so that a separate casing as such is eliminated.
Production costs may be further reduced if the wall of the casing in the zone of the converging lens is provided with two semi-cylindrical injection molded seals of translucent plastic material. Thus only one mold or forming device is required to be fabricated for producing the converging lens, the reflectors and the casing.
The parts forming the reflectors preferably join each other not only at the converging lens but also above and below the light source. Below the light source the reflectors may contain an opening near the socket to which the casing is connected and which forms a support for the casing. The reflectors and converging means together thus form a self-contained casing so that there is no need for a separate outer casing outside of the drum lens.
To prevent contamination of, and the deposition of dust on, the optically acting outer surfaces of the casing, an outer protective bell may be provided and this may be formed with vertically extending contours which impart breadth to the emerging light rays which would otherwise be seen by an observer from the front as a line of light extending in a vertical plane. Even with this improvement manufacture in accordance with the present invention is rendered simple and inexpensive.
The general perpendicular portion of the casing that forms the drum lens is a converging lens which may be of such height that it occupies a limited angle of a (that is, a above and below a horizontal axis through the center of the light source). It is at this angle where it is possible to deflect the light rays at right angles to the vertical axis of the casing. Preferably, therefore, this zone constituting the drum lens is formed from an echelon or Frensel lens, the cylindrical interior of which occupies the above-mentioned angle range of a. Preferably only the medium zone, that is the zone on either side of a horizontal axis passing through the light source, is formed as an ordinary converging lens. The zone above and below is stepped down to the abovestated limiting angle.
The zone of light from the light source and emerging frontally from the drum lens occupies the angle ,8 or an angle B on either side of the vertical axis and a plus [3 is equal to 180. In the B zone, the deflecting elements have acute angled prismatic optical contours on the inside lower edges that preferably extend at right angles to the central vertical axis of the casing. The upper edges are inclined to the central axis and in each instance at an angle such that the beam from the light source is totally reflected outwardly through the casing. Each of these individual prismatic elements is stepped on its outer face toward the adjacent individual elements preferably in such a manner that the outwardly reflected light rays strike the outer wall at right angles and pass through the outer wall without being diffracted.
The same applies in the case of the individual elements that are adjacent to the Frensel drum lens and extend downward to the socket over the angular range of'y in each instance. Also in the zones or ranges B and 'y, the stepped portions of the casing, instead of being parallel with the center axis, may be slightly inclined or curved with respect to this center line so that outwardly radial rays of light may be either scattered or converged. The Frensel lens can likewise be so designed that light rays, rather than being radiated at right angles to the center axis are radiated outward at a preselected angle or scattered to the central axis of the casing. Thus at least above and below the drum lens it is possible, without any substantial deviation, to dispense with the outer bell or globe having contours producing scatter and it is possible to eliminate the outer bell or globe except where necessary for preventing contamination.
DESCRIPTION OF THE DRAWINGS FIG. 1 is a vertical section through one embodiment of the panoramic light emitter.
FIG. 2 is a view similar to FIG. 1 rotated through 90 to illustrate the symmetry of the reflectors and the lens.
FIG. 3 is a vertical section through another embodiment of the panoramic light emitter.
FIG. 4 is an enlarged vertical section of the optical deflection elements illustrated in FIG. 3, illustrating their optical qualities.
DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 and 2 illustrate a suitable light source 1 which is fixed by means of support 2 in the center of a translucent cylindrically shaped housing 3. The support 2 is mechanically connected to a warning light housing 4. The warning light housing 4 contains generally the battery or a source of electric current and an electronic circuit with a light sensitive actuator switch commonly referred to as a day light switch. With the circuit in the warning light housing 4 the lamp or light source can be actuated constantly to provide a continuous light or, where desired, intermittently to provide a blinking light.
Within the cylindrical housing 3 there are a pair of reflectors 5 and 6 that are generally symmetrical having circular outer edges suitably secured to the housing 3. The reflectors 5 and 6 are formed as axially symmetrical profiled elements and the surfaces of the reflectors 5 and 6 facing the light source have the profile which extends over a parabola 7. The focal point of the parabola 7 is located at the center of the light source 1. The upper reflector 5 is attached to a cylindrical lens 8 and the reflector 6 is connected to the bottom wall 3b of housing 3. The housing 3 has an upper or top wall and the vertical axis of housing 3 is designated by the numeral la and extends through the center of light source 1.
The surface of reflectors 5 and 6 form bodies of rotation from the rotation of a parabolic arc or segment about the central axis la and thus have continuous parabolic curvatures emanating from the center line la. The dotted part of parabola 7 is illustrated only for exemplary purposes and does not form a part of the respective reflectors. The surface of the reflectors 5 and 6 have a high mirror finish so that all of the light rays striking this surface are reflected to right angles to the cylindrical wall 3c of housing 3.
The light which is radiated by the light source into the angular area a (Alpha) strikes the parabolic profile of the reflectors 5 and 6 and is reflected in a horizontal direction. The light which is radiated by the light source 1 into the angle area B (Beta) is also diffracted in a horizontal direction by the lens 8 which is an annular converging lens surrounding the light source 1. A projected diagonal line connecting the corners of the housing 3 is preferably tangential to the edges of the lens 8 (see FIG. 1) so that the outer diameter of the lens may be accurately determined. The height or vertical dimension of the lens 8 corresponds to the smallest distance between the reflectors 5 and 6.
With the above arrangement of the reflectors 5 and 6 and the lens 8, scattered light from the light source 1 is eliminated and all of the light produced by the light source 1 is radiated in a horizontal manner (with the exception of the part of the light source striking the lamp base or support 2). The horizontal projection of the light rays is illustrated in FIG. 1 and the numeral 9, for example, designates one of the light rays and illustrates how the light is reflected horizontally by means of the upper reflector 5.
In FIG. 2 there are illustrated two transparent struts or support members 10 which mechanically connect the lens 8 with the reflector 5. The reflector 5, in turn, is connected to the housing 3 so that by removing the housing 3 from the warning light housing 4 the lamp or light source 1 is exposed for changing or replacement.
The exterior of housing 3 as illustrated in FIG. 2 has a plurality of lenticular rings 1 1 which function to scatter the light hitting the housing walls vertically at a certain angle and provide an open cone of light so that the warning light is fully visible over the range of the cone. The light cone is provided to permit the light source to be visible when the light is suspended in an inclined position, or if it is intended that the light should be seen from a short distance, a light cone of this type is essential.
Referring now to FIGS. 3 and 4 where another embodiment of the invention is illustrated the light source 101 is supported from the base 105 by a lamp support 102. The base 105 forms a portion of the warning light housing 106 that contains the circuitry and battery similar to the housing 4 previously described. Numeral 104 is a housing of a synthetic translucent plastic material formed from two injection molded half semi-cylindrical portions 1040. The thread base 103 of the housing is threadedly secured to the base 105.
The portions 104a are semi-cylindrical and symmetrical to the vertical axis MM of housing 104 and may be formed in the same mold or forming apparatus. The segments are bonded to each other along the edges that are parallel to the vertical axis MM.
In the angular range designated by the angle 8 (Delta) in FIG. 3 the downwardly radiating light cannot be utilized since this range is employed for the lamp support 102 and the upper portion of base 103. Above and adjacent to the angular range 8 is an angular range 7 disposed symmetrically on opposite sides of the axis M as illustrated in FIG. 2 ('y). This angular range is occupied by the optical deflection element 1041; which comprises individual prismatic elements 107 (see FIG. 4). The elements 107 converge over a stepped formation and reflect the light entirely inward.
A similar optical deflection element 104a above the light source reflects the light source projected through the angular range B. The angular range B is symmetrical to the axis MM. The uppermost of the individual elements 107 is formed at 107a as a small transparent end plate. In lieu of the end plate 107a this area around the axis MM may be provided with a small circular opening which should be protected against dust. The housing 115 may also remain open above the area 107a.
The exterior surfaces of the deflection elements 104b and 104C taper in the upward and downward directions and the prisim-like elements 107 each has a vertical exterior 108 (FIG. 4) and a horizontally recessed or stepped portion 109 running toward the adjacent element 107. The vertical surface 108 may, if desired, have either a slanted or arcuate profile so that the light rays which will radiate outwardly therethrough can have either scattered or converging patterns. The deflection elements 104!) and 1046 are connected at their respective upper and lower edges to a generally vertical portion 104d of the cylindrical housing wall occupying the angular range 01' (Alpha prime) of the light emanating from the light source 101. This angular range is symmetrical about the horizontal axis I-I-H of the housing.
The angle a is the limiting angle which has to be precisely calculated and at which it is still just possible to obtain the required deflection of the light in the part 104d as well as in parts 104b and 104C in the direction at right angles to the axis MM. The portion 104d is an echelon or Frensel lens in the form of a drum lens. The center part l04f of the lens 104d has a conventional lens profile of a converging lens and the outer portions 104e are stepped and arranged to deflect the incident light at right angles to the axis MM and in a horizontal direction.
FIG. 4 illustrates in greater detail and larger scale a section of the portions 1104b and 104C and illustrates the light ray which emanates from the light source 101 and forms with the horizontal (I-II-I) and angle (Epsilon) greater than (Alpha Prime over 2). The figure shows how the light ray strikes a horizontal annular surface of a prismatic individual element 107 and is diffracted. The figure further shows how the diffracted ray 112 is totally reflected on the inclined annular face 113 in the direction 114 and passes horizontally from the outer annular face 108. In each individual element 107 and dependent upon the angle of incidence (Episilon) of each ray emanating from the light source 101, the inclination of the surface 113 is so selected that the required total reflection and deflection occur in the horizontal or substantially horizontal direction when the exterior surface or outer face also produces a further deflection or scattering of the light ray 114 that is when the outer face is not flat or perpendicular.
In FIG. 3 the dotted lines surrounding the housing 104 are intended to designate a transparent exterior bell 115. The bell may have curved portions running in a vertical direction which will disperse and impart breadth to the emerging light extending in a vertical plane as seen from the front. Also with these vertically elongated portions a small portion of the light may be scattered upward to provide for the instance where the warning light does not hang or is not positioned in the normal line of sight at the level of the arriving vehicle but hangs below the line of sight.
According to the provisions of the patent statues, I have explained the principle, preferred construction and mode of operation of my invention and have illustrated and described what I now consider to represent its best embodiments.
1. A panoramic light emitter for warning lamps comprising,
a light source having a vertical axis supported on said housing,
a lens non-rotatably secured to said housing and positioned symmetrically around said light source, said lens arranged to provide a light source for 360 around the vertical axis of said light source,
said lens having an upper prismatic portion, an intermediate converging portion and a lower prismatic portion,
said upper and lower prismatic portions each having a plurality of faces extending perpendicular to said light source vertical axis, said plurality of faces arranged in staggered relation to each other so that substantially all of the light beams emanating from said light source directed toward said plurality of faces will enter one of said faces,
said upper and lower prismatic portions each having a plurality of base portions arranged angularly to said faces so that the light beams emanating from said light source entering said faces are totally reflected on said base portions, and
said lens upper prismatic portion, intermediate converging portion and lower prismatic portion arranged so that substantially all of the light beams emanating from said light source are directed in a direction perpendicular to said vertical axis of said light source.
from said light source are spread apart in a nonperpendicular relation with the vertical axis of said light source.
5. A panoramic light emitter for warning lamps as set forth in claim 1 which includes,
a bell shaped transparent member positioned over said lens and secured to said housing, said bell shaped member including curved portions arranged to further diverge the light beams emanating from said light source.