Abstract:
A light source with an integral surface of revolution to project an emergency warning light signal for a vehicle in a substantially horizontal 360° arc. A centrally positioned mirror assembly has a plurality of light sources spaced about the mirror assembly.

Description:
FIELD OF THE INVENTION 
   This application generally relates to emergency lighting and in particular to an emergency warning light which employs a light source which emits a horizontal beam of light. 
   BACKGROUND OF THE INVENTION 
   In the past, many emergency warning lights have employed an omni-directional light source or a light source which generates a beam of light which is visible within in a particular limited, angular sector. For light sources which emit omni-directional light, a large amount of light is emitted upward or vertically providing little or no emergency warning value. On the other hand, a beam of light having a limited, angular sector of coverage generally needs to be rotated or oscillated in order to provide sufficient illumination which would amount to providing an emergency warning signal. There is a need for a simple configuration of an emergency warning light which primarily emits light in a substantially horizontal plane only. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1A  is a perspective view of a lens L 1  and base B 1  for a first embodiment of the invention in which a single, side emitting LED (light emitting diode) is used. 
       FIG. 1B  is a perspective view of a base B 1  for the first embodiment of the invention in which a single, side emitting LED SEL 1  is used. 
       FIG. 1C  is a side elevation view of the lens L 1  and base B 1  of  FIG. 1A . 
       FIG. 1D  is a cross-sectional view taken along lines  1 D— 1 D of  FIG. 1C  of the lens L 1  and base B 1  of  FIG. 1A . 
       FIG. 1E  is a side elevation view of a lens L 2  and base B 2  of a second embodiment of the invention, in which a single, side emitting LED is used. 
       FIG. 1F  is a cross-sectional view taken along line  1 F— 1 F of  FIG. 1E  of the lens L 2  of  FIG. 1E  assembled with the base B 2  of the second embodiment. 
       FIG. 1G  is a detailed view of the side emitting light source of the first and second embodiments including an LED and a surface of revolution SR 1 . 
       FIG. 2A  is a perspective view of a lens L 3  and base B 3 , similar to the lens L 1  and base B 1  of  FIG. 1A , for a third embodiment of the invention in which three side emitting LEDs (SEL 1 , SEL 2 , SEL 3 ) and a hexagonal reflective surface HRS are used. 
       FIG. 2B  is a perspective view of a base B 3  for the third embodiment of the invention in which three side emitting LEDs (SEL 1 , SEL 2 , SEL 3 ) and a hexagonal reflective surface HRS are used. 
       FIG. 2C  is a side elevation view of the lens L 3  and base B 3  of  FIG. 2A . 
       FIG. 2D  is a cross-sectional view taken along lines  2 D— 2 D of  FIG. 2C  of the lens L 3  of  FIG. 2A  assembled with the base B 3  of  FIG. 2B  of the third embodiment. 
       FIG. 2E  is a top plan view of a mounting bracket MB which may be used to support the three side emitting LEDs and the hexagonal reflective surface HRS of a fourth embodiment. 
       FIG. 2F  is a perspective view of the mounting bracket MB of  FIG. 2E . 
       FIG. 2G  is a side view of the mounting bracket MB of  FIG. 2E . 
       FIG. 2H  is a front view of the mounting bracket MB of  FIG. 2E . 
       FIG. 2I  is a schematic diagram of a top plan view of the three side emitting LEDs (SEL 1 , SEL 2 , SEL 3 ) and hexagonal reflective surface HRS of  FIGS. 2A–2H  illustrating the angles of the hexagonal reflective surface HRS and illustrating the positioning of the side emitting LEDS relative to transmitted beams TB and reflected beams RB 1 –RB 4  of light, according to the third and fourth embodiments. 
       FIG. 3A  is a perspective view of a lens L 5  for a fifth embodiment of the invention in which six upwardly directed LEDs (LED 1 –LED 6 )are used. 
       FIG. 3B  is a perspective view of a base B 5  for the fifth embodiment of the invention in which six LEDs and a surface of revolution SR 5  are used. 
       FIG. 3C  is a side elevation view of the lens L 5  of  FIG. 3A . 
       FIG. 3D  is a cross-sectional view taken along lines  3 D— 3 D of  FIG. 3C  of the lens L 5  of  FIG. 3A  assembled with the base B 5  of  FIG. 3B . 
       FIGS. 4–9  illustrate an alternative embodiment according to the invention in the form of a module which fits into different lens housings for vehicles such as lift trucks or tractors. 
       FIG. 10  is a schematic of a driver circuit of the invention where the frequency and duty cycle of the light source are determined by a micro controller. 
       FIG. 11  is a schematic of a driver circuit of the invention where the frequency and duty cycle of the light source are determined by a resistor and capacitor circuit. 
       FIG. 12  is a schematic of a driver circuit of the invention where the frequency and duty cycle of the light source are controlled by a micro controller and may be selected by the user from a number of preprogrammed patterns. 
   

   Corresponding reference characters indicate corresponding parts throughout the several views of the drawings. 
   DESCRIPTION OF THE INVENTION 
   Referring to  FIGS. 1A–1G , one preferred embodiment of the invention is illustrated. In particular,  FIG. 1A  is a perspective view of a lens L 1  for a first embodiment of the invention in which a single, side emitting LED is used.  FIG. 1B  is a perspective view of the base B 1  for a first embodiment of the invention in which the single, side emitting LED SEL 1  is illustrated. A side view of this first embodiment is illustrated in  FIG. 1C  and a cross-sectional view is illustrated in  FIG. 1D . In general, this light according to the invention includes a base B 1  and a light source SEL 1  supported by the base. In general, the light source SEL 1  includes an LED which emits at least a substantially horizontal beam of light and at least a substantially vertical beam of light. A surface of revolution SR 1  is positioned over and integral with the LED such that the vertical beam is directed substantially parallel to the horizontal beam of light that is emitted by the LED.  FIG. 1G  illustrates this aspect wherein light radiated by the LED is horizontally directed by the surface SR 1  into horizontal beams of light Hi and H 2  having about a 20 degree spread, although other spreads are contemplated. It is contemplated that surface SR 1  may direct or re-direct light by transmission, reflection, refraction, diffusion or any other type of optical directing so that the resulting light is substantially horizontal. In addition, the LEDs may emit horizontal beams of light H 3  without such beams intersecting or otherwise being involved with the surface SR 1 . 
   As noted above, the LED and SR 1  may be an integral unit in the form of a side emitting LED such as a LUXEON™ STAR manufactured and sold by LUMILEDS™. In one form, such side emitting LEDs are manufactured and sold in combination with a heat junction HJ upon which the LED is mounted to dissipate the heat generated by the LED. In this configuration, the base B 1  functions as a heat sink and is in contact with the heat junction HJ with a layer of thermal paste TP or other heat conducting material between the two surfaces. The side emitting LED may be fixed to the base B 1  by any engagement means such as pins P 1  as shown in  FIG. 1D . 
   As illustrated in  FIGS. 1A–1G , the surface of revolution SR 1  has an inverted conical shape which, in one of its simplest forms, may be generated by revolving an inverted right triangle about a vertical axis parallel to one of the legs of the triangle. This conical surface of revolution SR 1  has a linear directive surface DS 1 . It is also contemplated that any of the surfaces of revolution herein may have a directive surface DS 1  that is a parabolic surface, an elliptical surface, a hyperbolic surface or other surface which may or may not be a fluted surface. 
   The lens L 1  engages the base and encloses the side emitting LED SEL 1  including its surface of revolution SR 1 . The lens L 1  has a convex portion CP in the same plane as the substantially horizontal plane in which the light is emitted by the LED SEL 1 . The convex portion CP further focuses the light in this horizontal plane. The lens L 1  also has a di-optic portion DP adjacent to the convex portion CP which directs any light not within the substantially horizontal plane of light emitted by the LED SEL 1  into the horizontal plane or a parallel horizontal plane. The convex portion CP and the di-optic portion DP cause the light to appear taller to the observer. The inside surface of the lens L 1  has vertical flutes VF to make the light appear wider to the observer. The combined effect of the vertical flutes VF, convex portion CP, and di-optic portion DP of the lens. L 1  is to make the light appear to be larger and rectangular to the observer. Without these features of the lens L 1 , the light tends to appear to be a point source to an observer. 
   The lens L 1  and base B 1  may be joined by any method or structure. In one embodiment, a series of grooves GS in the base B 1  are filled with an epoxy or other potting compound and mated to the corresponding ribs in the mounting surface of the lens L 1 . This protects the LED SEL 1  under the lens L 1  from moisture, weather and other elements. In general, the side emitting LED or the lens or both may be colored or clear. 
   In general, it is contemplated that the light would include means for engaging a vehicle so that the light would provide an emergency warning signal for the vehicle. As illustrated in  FIGS. 1B and 1F , the light is provided with insets for engaging screws which may assist in the mounting of the light to a vehicle or which may be mounted to a mount which could be attached to the vehicle, such as by suction cups, magnets, adhesive pads or other well known techniques for supporting the light on the vehicle. In one embodiment, a permanent magnet BB is positioned within the base B 2  as shown in  FIGS. 1E–1F  for magnetic engagement to a metallic surface, such as a vehicle body. 
   As illustrated in  FIG. 1D , the light includes a printed circuit board PCB 1  adapted to engage a power source via a power cable (not shown). The board PCB 1  is positioned within and supported by the base B 1  and may be encapsulated in a weather resistant material such as a potting material, an epoxy material, a silicone material or any other material that would resist or inhibit moisture or other weather created conditions from significantly affecting the board&#39;s operation. The board is electrically connected to the LED for selectively energizing the LED when engaging a power source. This selective energization of the LED may include flashing according to a preprogrammed or manually implemented program or continuous illumination. 
   One aspect of the invention is that virtually all light is either directly emitted or directed into a substantially horizontal plane as a warning to observers so that substantially no light fails to warn an observer. The horizontal plane of light generally would provide an emergency warning signal to most observers in the horizontal plane surrounding the light. 
     FIGS. 2A–2I  illustrate another preferred embodiment according to the invention.  FIG. 2A  is a perspective view of a lens L 3  similar to the lens L 1  of  FIG. 1A , for a third embodiment of the invention in which three side emitting LEDs SEL 1 , SEL 2 , SEL 3  are used. 
   In the embodiment of  FIGS. 2A–2I , a mounting bracket MB or other base B 3  supports a plurality of side emitting light sources SEL 1 , SEL 2  and SEL 3  which together emit a substantially horizontal beam of light. A hexagonal reflective surface HRS is fixed to the base B 3  by a screw S 1  and positioned between the light sources for reflecting the horizontal beam of light such that the reflected light is substantially parallel to the horizontal beam of light emitted by the light sources themselves. Thus, as in the previous embodiment, essentially no light fails to warn an observer and substantially all light is used to generate an emergency warning signal. 
   As shown in  FIG. 2I , each surface of the hexagonal reflective surface HRS is positioned at an angle with respect to at least one of the side emitting light sources such that substantially all the light directed inwardly toward each surface is reflected outwardly away from the surface. The outwardly reflected light does not intersect and is not blocked by any of the plurality of side emitting light sources. In particular, it is noted that inwardly reflecting beams RB 1  and RB 2  are reflected by the surface and do not intersect the light source SEL 1 . Similarly, reflecting beams RB 3  and RB 4  which are much closer to the source SEL 1  are also reflected but do not intersect the source. Reflected beam RB 5  is reflected on the other side of the source that is immediately adjacent the surface reflecting beam RB 4  so that substantially all light directed inwardly by the light source is reflected outwardly. In addition, it is noted that transmitted beam TB 1  and TB 2  which are transmitted past the corner of the surfaces do not intersect the other light sources SEL 2  and SEL 3  so that substantially all transmitted light from the light sources is converted into an emergency warning light within the horizontal plane. In other words, a light beam such as beams RB 1 –RB 5  from a particular side emitting light source such as SEL 1  directed toward the center of the light are each reflected back past the particular side emitting light source without substantially intersecting a particular side emitting light source. In addition, a light beam from a particular side emitting light source such as SEL 1  directed past a vertical edge of the reflective surface such as beams TB 1  and TB 2  do not substantially intersect any of the plurality of side emitting light sources so that these light beams are also effectively used for emergency signaling. It is contemplated that one or more side emitting LEDs (not shown) could be mounted on top of the hexagonal reflecting surface HRS and used to create another plane of substantially horizontal light, or adapted to substantially direct light into the same horizontal plane as the other side emitting LEDs SEL 1 –SEL 3 . 
   As illustrated in  FIGS. 2A–2I , one preferred embodiment of the reflective surface contemplates that the surface comprises pairs (e.g., three) of flat mirrors, each pair having edges engaging one of the edges of the other adjacent pairs (e.g., the other two pairs). In certain pair configurations, the flat mirrors of a pair may be substantially perpendicular to each other. The mirror pairs may also be interconnected and made from a single block of material such that the mirror pairs can be attached to the base with a single screw, pin, or other means of attachment. In one embodiment, the mirror assembly is made from a single piece of polished metal and attached to the base B 3  by a screw S 1 . The light sources illustrated in  FIGS. 2A–2I  include a light emitting diode having an integral surface of revolution thereon. Such devices are mounted on a heat junction HJ which in turn is mounted on a heat sink such as the base B 3 , MB. Lens L 3  engages the base B 3  and encloses the light source and the surface of revolution. A printed circuit board PCB 3  is mounted within the base.  FIGS. 2E–2H  illustrate an alternative embodiment according to the invention wherein the light sources and reflective surface are mounted on a mounting bracket MB which engages a base similar to the base B 3 . In this configuration, the printed circuit board PCB 3  is mounted under the bracket and engages the base. Also, in this configuration it is noted that the base has a higher vertical profile than the base B 3  of  FIGS. 2A–2D . 
   Referring to  FIGS. 3A–3D , a fifth embodiment of the invention is illustrated.  FIG. 3C  is an elevated side view and  FIG. 3A  is a perspective view of a lens L 5  for the fifth embodiment which includes six LEDs, L 1 –L 6  as shown in greater detail in  FIG. 3B . Each of the light emitting diodes is supported by a base B 5  and emits a substantially vertical beam of light. A surface of revolution SR 5  is positioned over the lights and between the lights for directing the vertical beams of light such that the directed beam is substantially horizontal. The LEDs L 1 –L 6  are arranged in a circular pattern on the base and the directive surface is a surface of revolution revolved around an axis such that the surface of revolution is positioned above the LEDs and the axis is oriented substantially vertically and positioned centrally within the circular pattern. A printed circuit board may be mounted within the base such as illustrated by printed circuit board PCB 5  in  FIG. 3D . One specific embodiment of a schematic of a printed circuit board is illustrated in  FIG. 10 . The LEDs illustrated in  FIG. 3C  may be a LUXEON™ RING manufactured by LUMILEDS™. 
     FIGS. 4 to 9  illustrate a family of embodiments.  FIG. 8  shows an elevated side view of a bracket module supporting a platform on top of which there is a side emitting LED. This module also contains the driver circuit for the LED.  FIG. 9  shows a perspective view of this same module. This module is made to fit into a number of lenses or housings to meet different specifications.  FIG. 4  shows one housing embodiment and  FIG. 5  shows a cross section of that housing with the module of  FIG. 8–9  fit into it.  FIG. 6  shows a housing that meets European DIN 14620 size standards for warning beacons, and  FIG. 7  shows a cross section of that housing with the module of  FIGS. 8–9  fit into it. The embodiments of  FIGS. 4–9  include convex and di-optic portions similar to the convex portion CP and di-optic portion DP of the lens L 1  in  FIG. 1D . In addition, an additional di-optic portion is illustrated below the convex portion of the housing. Other housings can be made to meet different or changing size specifications, while utilizing this same internal module in those new housings. 
   Referring to  FIG. 10 , a schematic diagram of a circuit of a printed circuit board of the invention for powering a single LED is illustrated. Those skilled in the art will understand that this circuit may be modified to power multiple LEDs or that multiple circuits, one for each LED, may be employed for embodiments of the invention which have more than one LED. A power source, such as a 12 vdc vehicle battery is connected to terminals PWRIN(+) 1  and GND 1 . After transient clamping and filtering, the voltage is applied to switching regulator U 1  which steps down the DC volts to about 4.2 vdc to be applied to the LED via pins P 1  and P 2  of the connector. The LED is powered in a constant current mode (approx. 375 milliamps). Feedback via resistor R 4  is provided to the switching regulator U 1  as a gain control to vary the PWM duty cycle of the regulator to maintain constant current. Switch Q 2  limits the output voltage if no LED is connected to the circuit to avoid U 1  operating in a runaway mode in which U 1  attempts to constantly increase the current. Q 2  indicates to U 1  to skip PWM adjustment cycles when no LED is connected to the circuit to avoid runaway operation. Programmable microcontroller U 3  controls bipolar transistor U 2  to control the flash pattern of the LED, turning it on and off. 
   Referring to  FIG. 11 , a power source of between 10 and 60V dc is connected to the input terminals J 3  (+) and J 4  (−), D 2  then provides reverse polarity protection and D 3  provides transient voltage protection. The voltage is then applied to the switching regulator U 1 , the feedback pin of which is connected to the junction between R 1 , R 3 , R 4  and the LED cathode thus providing a fixed 5V output at this point. With the LED switched off the voltage at the feedback pin FB is maintained at 5V by raising the output voltage of U 1  sufficiently to maintain 5V in the center of the resistor divider network created by R 1  and R 4 . When the transistor Q 1  is switched on resistor R 3  is connected to ground, in order to maintain the feedback pin at 5V the output voltage from U 1  is increased until the voltage across R 1  and hence the LED is sufficient to allow the LED to conduct, the LED is therefore energized at a constant current determined by the value of R 3 . 
   Timer IC, U 2 , controls the transistor Q 1  to control the flash pattern, the frequency and duty cycle being determined by R 5 , R 6  and C 3 . 
   Referring to  FIG. 12 , a power source of between 10 and 60V dc is connected to the input terminals J 3  (+) and J 4  (−), D 2  then provides reverse polarity protection and D 3  provides transient voltage protection. The voltage is then applied to the switching regulator U 1 , the feedback pin FB of which is connected to the junction between R 1 , R 3 , R 4  and the LED cathode thus providing a fixed 3.3V output at this point. With the LED switched off the voltage at the feedback pin is maintained at 3.3V by raising the output voltage of U 1  sufficiently to maintain 3.3V in the center of the resistor divider network created by R 1  and R 4 . When the transistor Q 1  is switched on resistor R 3  is connected to ground, in order to maintain the feedback pin at 3.3V the output voltage from U 1  is increased until the voltage across R 1  and hence the LED is sufficient to allow the LED to conduct, the LED is therefore energized at a constant current determined by the value of R 3 . 
   Programmable micro-controller, U 2 , controls the transistor Q 1  to control the flash pattern, two terminals at J 5  are provided for the end user to “short together” in order to select a flash pattern from a number of pre-programmed alternatives. 
   When introducing elements of the present invention of the preferred embodiments thereof, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of the elements. The terms “comprising”, “including” and “having” are intended to be inclusive and meant that there may be additional elements other than the listed elements. 
   As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.