Patent Application
20080239713
The present invention relates to exterior lighting systems and more particularly to solar-powered exterior lighting systems.
The exterior lighting of building doors and entranceways is a common and useful practice. Such lighting enhances safety, allows inhabitants to view who is at the door before opening the door and enhances the aesthetic appeal of the residence or other building.
In locations where no exterior light has previously been installed, installing a retrofit exterior light is typically beyond the skill set of the average do-it-yourselfer. Such an installation requires cutting holes in the building exterior and extending electrical service to the desired installation site. Thus, the average person likely would need to retain a professional contractor at a relatively high cost to install an exterior light.
The aforementioned problems are overcome by the present invention comprising a self-contained, solar-powered, battery-operated lighting fixture. The fixture can be mounted on a building door or on a building in an area adjacent the door. In a first embodiment, the light source, the solar collector and the battery are contained within a common housing.
The present invention has several advantages over traditional exterior lights. Most notably, the fixture can be easily installed by a homeowner or other do-it-yourselfer without the need to cut holes in the building or to extend electrical service. This greatly reduces the cost of providing exterior lighting.
In a current embodiment, the lighting system includes a solar collector that is removable from the fixture housing, enabling the collector to be located in a different location. This embodiment enables the collector to be located in a location receiving more ambient light than the location of the fixture, for example when the fixture is located under a roof overhang, a soffit, an awning or other shaded area.
These and other objects, advantages, and features of the invention will be fully understood and appreciated by reference to the description of the current embodiments and the drawings.
A solar door lighting system constructed in accordance with a first embodiment of the invention is illustrated in
The housing 12 provides a weather-tight enclosure for the light source 20, power source 22 and circuit 16. The housing 12 includes a main housing body 24, a first end cap 26, a second end cap 28 and a light source window or lens 32. The first end cap 26 interfits with the housing body 24 at a first end 52 of the housing body 24. The second end cap 28 interfits with the housing body 24 at a second opposite end 54 of the housing body 24. The end caps 26 and 28 may be secured to the housing body 24 using a press fit, a snap fit, adhesive, fasteners such as screws or clips and/or any other suitable connection means.
The current configuration of the housing 12 is illustrated in the drawings. The housing 12 could be constructed in other configurations. In the current embodiment, the main housing body 24 is an aluminum extrusion; and the first end cap 26 and the second end cap 28 are injection molded plastic. These components could be constructed from any material providing suitable performance and aesthetics, including metal or wood.
The main housing body 24 has a solar collector support surface 30. The solar collector 14 may be secured to the solar collector support surface 30 using pressure sensitive adhesive tape or any other suitable attachment means, such as screws, an interference fit, and/or a snap fit. The solar collector support surface 30 is oriented away from the mounting surface so that the surface 30 is exposed to ambient light when the unit 10 is installed.
The circuit 16 is implemented on a circuit board 40. The main housing body 24 includes a circuit site 38 that receives and supports the circuit board 40. Alternatively, the circuit site 38 may be located in any other suitable location within the main housing body 24.
The power source 22 is a battery contained within the housing 12. The main housing body 24 includes a battery compartment 42 in which the battery is located and retained.
The main housing body 24 has a light source chamber 44 where the light source 20 is mounted. The light source chamber 44 is located so that the light source 20 will illuminate a door 46 and/or the area surrounding the door when the lighting system 10 is installed on or in proximity to the door 46. See
The main housing body 24 also defines a light source window slot 50 adjacent to the light source chamber 44. The light source window slot 50 receives the light source window or lens 32 through which light from the light sources 20 passes. The light source window 32 is fabricated of acrylic plastic or any other suitable transparent or translucent material. In the current embodiment, the material has a 93% light transmittance and a refractive index of 1.49.
During installation (to be described), the solar collector 14 may either be attached to the solar collector support surface 30 of the main housing body 24 or installed separate from the housing body 24. See
The rechargeable power source or battery 22 1) receives and stores electrical power from the solar collector 14 and 2) supplies electrical power to the light source 20 through the circuit 16. The current rechargeable power source 22 is three 1300 milliamp-hour (mAh) 1.2 volt (V) nickel-metal hydride (Ni-MH) rechargeable batteries. Other power sources can be utilized as will be recognized by those skilled in the art.
The current light source 20 is one or more light emitting diodes (LEDs). Alternatively, the light source 20 may be one or more other illuminators as will be recognized by those skilled in the art. In the current embodiment, the light source 20 includes four 10,000 millicandle (mCD) LEDs (light-emitting diodes).
The circuit 16 controls the charging of the battery 22 and the illumination of the light source 20. Appropriate electrical wiring 62 interconnects the circuit 16 to the solar collector 14, the light source 20 and the battery 22.
As noted above, the solar collector 14 converts light energy to electrical energy. The presence of ambient light on the collector 14 causes electrical energy or power to be supplied both to the battery 22 and to the light source 20 (depending on the state of the photodiode 58).
The photocell or photodiode 58 is responsive to the ambient light to turn off the light source 20 “during the day” or when the ambient light is relatively high. Specifically, the photodiode 58 is conductive when the ambient light is above a threshold level and is nonconductive when the ambient light is below the threshold level. Consequently, when the amount of ambient light striking the photocell 58 is relatively high, the photocell 58 turns off the light source 20 by turning off the transistors 66 and 68. Conversely, when the amount of ambient light striking the photocell 58 is relatively low, the photocell turns on the light source 20 by turning on the transistors 66 and therefore 68.
The circuit 16 can be of any configuration providing the desired performance. Those skilled in the art will recognize numerous circuit configurations utilizing various components that will provide suitable performance for the current invention. One such configuration includes the photodiode 58, a PNP transistor 66, an NPN transistor 68, a 100 kilo-ohm (K) resistor 70, and a pair of double-pole, double-throw (DPDT) switches 72.
The system 10 may be installed in multiple ways as will be recognized by those skilled in the art. For example, the system 10 could be installed using brackets, fasteners, double-sided tape, adhesive or any other suitable attachment means (not shown). Alternatively, the system 10 could be installed directly on the door or the building using any of the aforementioned attachment means. For example, the solar collector 14 could be installed using mounting tabs 78 defining mounting holes 80 (
The system 10 can be installed in any location to illuminate a building opening 46 such as a door or a window. As illustrated in
The above description is that of the current embodiments of the invention. Various alterations and changes can be made without departing from the spirit and broader aspects of the invention as defined in the appended claims, which are to be interpreted in accordance with the principles of patent law including the doctrine of equivalents. Any reference to claim elements in the singular, for example, using the articles “a,” “an,” “the” or “said,” is not to be construed as limiting the element to the singular.
