Patent Publication Number: US-7708425-B2

Title: Removable emergency light

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   Not applicable. 
   FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
   Not applicable. 
   SEQUENCE LISTING OR PROGRAM 
   Not applicable. 
   BACKGROUND 
   1. Field of Invention 
   The present invention relates generally to removable emergency lighting, more particularly to a removable emergency light that can be used as a flashlight in case of a power outage. 
   2. Prior Art 
   Emergency safety lighting is commonly used to provide light when a power outage occurs. The lights are able to function during a power outage by using batteries that energize a light bulb. This process illuminates the area directly around the light. 
   Emergency lighting is mainly used in commercial buildings to direct occupants to an exit in the event of a power outage. Emergency lighting is not required or normally used in a personal residence because occupants will usually use a flashlight; also, the cost of placing emergency lighting in a residence is prohibitive because emergency lighting requires special housing and wiring. There are several problems with using a flashlight during a power outage. One is finding a flashlight in the dark and, two, even when a flashlight is found it may not have batteries and would be useless. 
   U.S. Pat. No. 5,684,378 (1997) teaches a flashlight light that can be plugged into a standard wall socket. Such a device poses a hazard to children who would be attracted to the socket by the flashlight. Because the flashlight sticks out from the wall; it would be in a position to be easily damaged by movement along the wall. Also having a flashlight on the wall may not be compatible with the interior design space. 
   Patents such as U.S. Pat. No. 6,969,181 (2005) teaches safety lighting that can be hidden and recessed in a wall. Such devices are too costly for the average homeowner and would not provide light to illuminate an area were it was not installed, such as a closet or cabinet. 
   The prior art lacks an emergency light that can be placed in a standard 22.5 cubic inch, single gang electrical box; be easily wired into a standard electrical system; and be removed in a time of emergency. 
   BACKGROUND OF INVENTION—OBJECTS AND ADVANTAGES 
   Accordingly, besides the other objects and advantages that will become apparent, the main objective of the present invention is to have an emergency light that fits into a standard 22.5 cubic inch, single gang electrical box; the light being removable from the gang box to act as a portable light source. In addition, there are other objects and advantages to the present invention which are: 
   (a) to provide a removable emergency light that can be installed in a 22.5 cubic inch, single gang electrical box. Before now, an emergency flashlight that had the components to sense a power failure was too large to fit in a 22.5 cubic inch, single gang electrical box; 
   (b) to provide a portable light that can easily be found and used in multiple areas during power failure in a building. This allows a person to use light to look in areas that would not be illuminated by emergency lighting (such as a closet or drawer); 
   (c) to provide a portable light that is rechargeable and can be used as needed; 
   (d) to provide an emergency light that is compatible with any interior design space; 
   (e) to provide a rechargeable flashlight that is recessed within the wall were the lens of the flashlight is flush with the wall, thus eliminating the possibility of snags; 
   (f) to provide an inexpensive means for having emergency lighting, because the light fits into a 22.5 cubic inch, single gang electrical box and requires no change to a buildings electrical layout, the invention is less expensive to install than current emergency lighting; and 
   (g) to provide an emergency light that can be placed in an existing electrical layout or in a new construction electrical layout. 
   Further objectives and advantages are to provide a device that can be easily placed anywhere in a building. Because the light fits in a 22.5 cubic inch, single gang electrical box, the device can easily be place in multiple locations in a building. The invention can be easily modified to include a photo cell that would allow it to function as a night light. In addition, the light can be placed in a water proof housing unit and placed outside. The removable emergency light can modified to fit in a camping trailer, utility trailer or RV. This would allow easy access to a charged light that could be used during camping or other outdoor activities. Still further objects and advantages will become apparent from a consideration of the ensuing description and drawings. 
   SUMMARY 
   In accordance with the present invention a removable emergency light comprising a housing that fits in a 22.5 cubic inch, single gang electrical box and a removable, portable light that turns on during a power failure. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Additional features and advantages of the invention will be apparent from the detailed description which follows, taken in conjunction with the accompanying drawings, which together illustrate, by way of example, features of the invention; and, wherein: 
       FIG. 1  is a perspective view of the removable emergency light with visible components; 
       FIG. 2  is the wiring and component diagram; 
       FIG. 3  is a perspective view of the removable emergency light with a partial wall; 
       FIG. 4  is a view showing how the unit is wired into a standard electrical system; 
       FIG. 5  is a front view of the circuit panel; 
       FIG. 6  is a bottom view of the circuit panel; 
   

   Reference will now be made to the exemplary embodiments illustrated, and specific language will be used herein to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. 
   DETAILED DESCRIPTION OF EXAMPLE EMBODIMENT(S) 
   In accordance with  FIG. 1  the removable emergency light  4  can be place in a 22.5 cubic inch, single gang electrical box  8 . Light casing  12  connects to a gang box  8 . Casing  12  can be made from any suitable material but in this embodiment it is made of Lexan Plastic. Screw holes  16  are used to secure casing  12  to the gang box  8 . Casing  12  is hard wired into a standard electrical system (see  FIG. 4 ). Flanges  20  are located on both sides of casing  12  and are used to prevent light housing  24  from moving vertically. In addition, flanges  20  are connected to a standard electrical system (see  FIG. 4 ). 
   Light housing  24  has backing  28  that is used to cover the back side of housing  24  and lens  32  is used to cover the front of light housing  24 . Backing  28  and lens  32  are secured in place to keep batteries  36  and circuit panel envelope  38  in light housing  24 . Circuit panel envelope  38  is bent at ninety degrees to reduce the size of light housing  24 . 
   Circuit panel envelope  38  is a representation of the space occupied by the components on the electrical panel (see  FIG. 2 ). It is to be understood that the components are not enclosed, but are placed on a circuit panel. Bending circuit panel envelope  38  ninety degrees, allows light housing  24  to be small enough to fit into gang box  8 . The circuit envelope is typically one inch wide and the vertical portion is typically 2.25 inches tall and the horizontal portion is typically 2.5 inches long. 
   Groove  42  runs along both sides of light housing  24  and match with flanges  20  on casing  12 . Light housing  24  has electrical leads  43  and  44  that mate with the electrical leads in casing  12  (see  FIG. 4 ). This allows current to flow into light housing  24  when placed in casing  12 . 
   A single or plurality of batteries  36  may be used; in this embodiment four rechargeable batteries are used. Switch  46  is used to toggle light emitting diode (“LED”) lights  50  on and off. Red LED light  54  indicates when batteries  36  are charging. Red LED light is optional and can be any color. Gang box  8  and Casing  12  are covered with a standard switch plate  58  with opening  62 . 
   Lens  32  is made of clear Lexan Plastic but any suitable clear material can be used. Light housing  24  and backing  28  are made of Lexan Plastic but any suitable material may used. Circuit panel envelop  38  is wired in accordance with  FIG. 2  and is composed of material commonly used in the art. Batteries  36  can be any type of standard battery commonly used in the art and in this embodiment they are NiCD 4.8V 700 mAh batteries. Lights  50  can be any type of light but in this embodiment it is 3 white LEDs 40000 mcd 3.4 v 20 ma. 
   The typical dimensions for the light housing  24  are: length 2.5 inches, width 1.17 inches, height at end 2.5 inches and height in middle 1.9 inches. Light housing  24  is typically made of ⅛ inch thick plastic. 
     FIG. 2  shows the components of circuitry of the circuit panel envelope ( FIG. 1 ,  38 ). In this embodiment the circuit panel is designed for a connection to a standard 120 V AC 60 HZ electrical system. This is a standard power supply in most commercial and residential buildings. The circuit operates as follows. When the flashlight is not plugged into an AC outlet, diode D 4  prevents any current flow from battery B to Q 1 . Thus the emitter of Q 2  transistor is directly connected to the negative terminal of the battery B and its base is positively polarized through R 5 . In this way the base-emitter junction of the transistor is directly polarized turning on the collector-emitter junction and allowing current to flow from battery B to ML (main LEDs). 
   When the flashlight is plugged in to the 120V AC and charging, the charging red 1.9 vdc 20 ma LED indicator (CL) is on while the main LEDs (ML) are off. 
   Note that Q 1  is turned on as the base has a positive supply given by R 2  and the charging led CL has a 1.9 junction drop that remains constant, as it behaves as a zener diode Thus the circuit around Q 1  configures a constant current supply. 
   In order to turn off Q 2  we need its base-emitter junction forward drop to be lower than 07 volts or even better to have VbeQ2 negative. While charging, the measured voltage at the top of the voltage divider, given by R 5  and R 6  is around 4.7 volts. Supply voltage is approximately 0.7 volts above, due to D 4  forward drop, or around 5.7 volts. At Q 1 &#39;s collector we have 5.4−3.9=8.0 volts. And the voltage divider sets Q 2 &#39;s base at around 0.2 volts. VbeQ2=−0.5 volts inversely polarized and Q 2  remains in cut-off. The location of switch  46  is indicated on the wiring diagram. 
     FIG. 3  shows the emergency light inside gang box  8 . The visible portion of the removable light is lens  32 . The remainder of the light is covered by standard switch plate  58  that is flush with wall  64 . Gang box  8  is located inside the wall cavity. 
     FIG. 4  shows how the casing  12  is wired into a standard electrical system. Black wire  68  (power wire) is connected to first flange  20 . White wire  72  (neutral wire) is connected to the second flange  20 . Any type of standard wire connection such as a pig tail or screws can be used to connect black wire  68  and white wire  72  to casing  12 . For this embodiment a pig tail is used. Current is passed into light housing  24  (see  FIG. 1 ) through flanges  20  into leads  43  and  44  (see  FIG. 1 ). 
     FIG. 5  shows a front view of the vertical portion of the circuit panel diagramed in  FIG. 3 . LED lights  50  are used to provide light and red LED lights  54  turns on when the batteries are charging. 
     FIG. 6  shows the underside of the horizontal portion of the circuit panel diagramed in  FIG. 2 . Battery connection  76  is shown. The other items of the circuit panel are labeled the same as in  FIG. 2 . 
   Operation— FIG. 1  and  FIG. 3   
   The manner for using the Removable Emergency Light is as follows. Casing  12  is hard wired into an existing electrical system inside a gang box  8 . When light housing  24  is placed in casing  12 , the current from a standard power source will charge batteries  36  until they reach full power capacity. While the batteries  36  are charging, Red LED light  54  is on. When the batteries  36  have reached full capacity red LED light  54  turns off. 
   When power failure occurs the batteries  36  are activated and supply power to turn on lights  50 . Light housing  24  can be removed from casing  12 . In this embodiment the light casing  12  is pushed, releasing a locking spring (not shown) that pushes light casing  12  partial, through the opening  62  in standard switch plate  58 . The locking spring described is a commonly used locking spring where the spring is kept under pressure by a lock until the spring is depressed, releasing the lock. In addition to a locking spring, a plastic clip can be used. When light housing  24  is removed from casing  12 , lights  50  can be turned on and off by toggling switch  46 . Light housing  24  can be returned to casing  12  through opening  62  to re-charge batteries  36 . Lights  50  remain off while housing  24  is located inside casing  12  unless a power failure occurs. 
   From the above description the advantages of the removable emergency light become evident: 
   (a) to provide a removable emergency light that can be installed in a 22.5 cubic inch, single gang electrical box; 
   (b) to provide a portable light that can easily be found and used in multiple areas during power failure in a building. This allows a person to use light to look in areas that would not be illuminated by emergency lighting; 
   (c) to provide a portable light that is rechargeable and can be used as needed; 
   (d) to provide an emergency light that is compatible with any interior design space; 
   (e) to provide a rechargeable flashlight that is flush with the wall, thus eliminating the possibility of snags; 
   (f) to provide an inexpensive means for having emergency lighting, because the light fits into a 22.5 cubic inch, single gang electrical box and requires no change to a buildings electrical layout, the invention is less expensive to install than current emergency lighting; 
   (g) the light can easily be placed anywhere in a building because of the ability to effortlessly be integrated into a buildings existing electrical plan; and 
   (h) the removable emergency light is an effective low cost alternative to other products currently available on the market. 
   While the forgoing examples are illustrative of the principles of the present invention in one or more particular applications, it will be apparent to those of ordinary skill in the art that numerous modifications in form, usage and details of implementation can be made without the exercise of inventive faculty, and without departing from the principles and concepts of the invention. Accordingly, it is not intended that the invention be limited, except as by the claims set forth below.