Solar panels are frequently used to recharge batteries during the day that then subsequently are able to power lights at night. Solar panels may serve multiple functions, and, although it is very common for a solar panel to be positioned away from a light source, some outdoor light assemblies use a solar panel as a cover to a container that contains electronics and other components that need to be protected against water exposure and inclement weather. Solar light assemblies may be positioned at variable heights from the ground, with variable difficulty and safety issues associated. It is safe and easy to service solar light systems that are close to the ground, such as walkway and construction lights. For larger outdoor light assemblies, such as those that can provide street or park lighting, the light is frequently mounted several meters above the ground on a pole, such as those shown in U.S. Pat. Nos. 6,060,658, 5,149,188, 4,281,369 and 4,200,904. It is not a simple task to remove a solar panel mounted high above the ground for the purpose of accessing electronics when servicing is required. In order to make a light assembly more versatile, it is advantageous to be able to adjust the direction of a light rather than always having a light that shines straight down.
A further consideration is the balance between aesthetics, the direction a light needs to shine, and the orientation of a solar panel relative to the southern sky (for the northern hemisphere). When more than one light is incorporated into a single pole mounted light assembly, the posture of a solar panel ideally angles the panel toward the southern sky, but a solar panel can be postured in a southerly direction many different ways. Usually, it is considered to be more aesthetically pleasing to keep a perimeter of a rectangular solar panel parallel to a reference plane, so there are two preferred ways to posture a rectangular solar panel: a vertical posture or a horizontal posture. A light assembly designed for a particular orientation and tilt of the solar panel will determine the position of a pole and, therefore, the lights. Even if the lights are fully adjustable, the pole might happen to block one of the lights from pointing in a desired direction, so there is also a need for versatility with regard to the posture of a solar panel on a two light solar lighting system so the pole doesn't undesirably interfere with the light cast.
The present invention is a solar powered light system that is a suitable alternative to conventional pole mounted street or park lighting, especially for areas that are not already supplied with power. A light having a shroud is hingedly attached to a housing. The shroud allows the light to be tilted such that it can provide vertical illumination of the ground, and by tilting the light, horizontal illumination. There are numerous tilt positions between these two extremes to provide a broad range of illumination. By excessively tilting the light beyond 90 degrees, the shroud swings away from the housing to expose the contents of the housing. With this easy access to the inside of the housing, there is no longer a need to remove the solar panel that covers the housing. Although a light assembly can be flat mounted to disguise the presence of a solar panel, the solar panel may be tilted to face south such that the light of the sun is more efficiently converted into power. An additional benefit of the present invention is that the solar panel itself may be used as a protective cover, or lid, for the housing of the solar light assembly which contains weather-sensitive components.
For additional versatility when installing a solar light assembly, a frame that supports a solar panel can be designed to accept different housings in different orientations. A frame mounted in a horizontal plane will cause a solar panel to face straight up, so when a light pole is installed in the ground there is no need to consult a compass. A flat mounted frame should be used with flat mounted housings to provide maximum versatility. For a frame to be postured to face the southern sky, the pole needs to be rotated correctly to cause the solar panel to be postured toward south. A postured frame should be used with sloped housings. Because convention has caused virtually all commercially available solar panels to be rectangular, a sloped housing can ideally be rotated 90 degrees such that the solar panel can face the southern sky by assuming either a horizontal posture or a vertical posture. This is beneficial during the installation of a solar light assembly to prevent a situation where a light pole is blocking a light from shining in a desired direction. At an installation site, the housings can be lifted out of the frame, rotated 90 degrees, and then dropped back into the frame before the solar panel is secured as a cover for the frame and housings. Once this is done, the solar light assembly can be installed with a southern vertical posture rather than a southern horizontal posture, or vice versa.
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The focus of the present invention is on combining a tilt feature of a solar light system with easy access to electrical components that may need to be serviced or replaced. An additional benefit is combining the above features with the ability to rotate a tilted light 360 degrees, thereby giving a very broad illumination range. This detailed description will begin by describing the first preferred embodiment, shown in
The above are combined to bring the solar light assembly 0 together into a low maintenance outdoor lighting solution. Wiring, which is usually just low voltage insulated wires that meet local codes, is not shown. The most preferred use of the solar powered light assembly of the present invention is as a street or park light, as shown in
A solar panel 20 that is well suited for use with the solar light assembly 0 of the present invention should be substantially impervious to harsh conditions. The preferred solar panel, shown in FIGS. 1,4,5,8, 10, 15, 19 and 24 is a flat panel that is formed in layers such that an array of solar cells are encased in a durable transparent material, such as a 100 watt or larger standard crystalline solar panel designed for use with 12 volt systems. The solar panel's perimeter is typically protected by a rigid border, which may also be used to support the solar panel. The solar panel's underside, opposite the collection surface, has a junction box 24 with electrical leads that carry the potential gathered by the collection surface of the solar panel. These electrical leads are connected to a system controller 72 that is electrically connected to a rechargeable battery that powers at least one light 70 of the system. The battery, not shown, is preferably kept in an underground battery container to limit the temperature extremes the battery will experience.
The top of the solar light assembly 0 must be covered to prevent the ingress of water, so the solar panel 20 also functions as a cover for the assembly. A frame 30 is used to protect and support the solar panel in a desired position. The frame has at least one large hole 36 that accepts a housing 40. It is understood that it may be desirable to precisely size the length and width of the frame of a solar light assembly so that it precisely fits a particular solar panel. The frame can be all one material, as shown in
For a flat mounted solar panel, edges 32 of the frame 30 are preferably high enough to conceal the solar panel 20 from view by someone on the ground, which may reduce the likelihood of vandalism being directed against the solar panel. The edges can be very short, preferably only a few centimeters high. Although edges are not absolutely necessary, they are preferred because they offer added protection to the solar panel while maintaining a uniform appearance for the solar light assembly 0. The tray portion of the frame additionally provides protection for wiring that extends from the battery. This wiring can simply be run through the pole and then routed over the tray portion and down into a housing 40 through a hole 36 in the frame. When viewed from ground level, the orientation that would normally be seen by someone walking under the solar powered light assembly, the tray portion 34 substantially frames a housing.
The tray portion of the frame 30 should have at least one drainage passageway 38, such as a groove cut through the tray portion, to prevent water from collecting in the solar light assembly. Obviously, if the tray portion is a mesh material, then there is no need to provide additional drainage. If drainage might be a problem, a rain barrier ridge 52 should also be provided to divert water so it doesn't flow into a housing 40. The rain barrier ridge can just be an additional structure on the tray that is raised relative to a surface of the tray portion that may collect water. As shown in
A housing 40 is made from a durable and rigid material that may be stamped, injection molded, or otherwise formed. Suitable materials include plastic, aluminum, steel, polyester, fiberglass, nylon, vinyl, carbon fiber materials, polycarbonate, or other composite materials that are substantially impervious to fracturing. There must be enough rigidity in the material so that an installed housing maintains its shape even when being rotated to a desired position. The most preferred method of making a housing is by thermoforming it from a single sheet of ABS plastic or polycarbonate. The thickness of the sheet will usually be between about five and ten millimeters, but will depend upon the material that is used and the overall size of a housing. Although a housing can be virtually any desired shape, the most preferred shape, shown in
A disc 50 extends outwardly from the open end of a housing 40, as shown in
A shroud 60 is housed within a housing 40 when the illumination cast by a light 70 is vertical, herein defined to be zero degrees of tilt. When a light is tilted away from the face 44 of a housing, the shroud similarly swings out of the housing to conceal the aperture 46 that would otherwise be exposed in the absence of a shroud. A shroud has an arcuate portion 62 that is substantially a uniform distance from a hinge 66. The shroud also has triangular sides 64 at opposing ends that cover the area between the arcuate portion and the hinge. The triangular sides are adjacent opposing sides of a housing, preferably abutting the sides 42 of a housing. A formed seal or weather stripping can be used between a housing and shroud to prevent insects from entering the housing. The aperture of the housing is covered by the light and the shroud at any angle between about zero degrees of tilt and about ninety degrees of tilt, ninety degrees being where the illumination cast by the light is horizontal. The degrees of tilt can be fixed in a desired position by fasteners that pass through the housing and secure to the triangular sides, as shown in
The light 70 is preferably an array of bright white light emitting diodes (LEDs) that are sealed into a weatherproof acrylic brick, but other suitable or alternative light sources can be substituted. A 120 LED brick light is well suited for the solar light assembly 0 because it provides a uniform dispersion of light that is adequate for most uses. The light is mounted near or to the face 44 of the housing 40 using at least one hinge means 66. The light is preferably also fixed to the shroud 60, such as by using fasteners or adhesive. When the light is tilted well beyond ninety degrees, the back of the light is accessible. If desired, the system controller or other electronics can be mounted to the back of the light, such as with fasteners or adhesive. Alternatively, as shown in FIGS. 3,4,5,7,8 and 10, an appropriately sized holder 74 can be fixed to one of the sides 42 of the housing 40, or even fixed to the back of the light, which will provide easier access to electronics that can simply be slipped out of their holder to be tested or replaced. Wiring can just hang loosely within the housing because once the rotation and tilt of a light are fixed, there should not be any reason the wiring will undergo additional movement.
In conjunction with using an energy efficient light, an energy-conserving switch, not shown, can be used with the solar powered light assembly. Examples of energy-conserving switches include motion sensors, dusk-to-dawn photo-electric sensors, timers, remote controls, and combinations of the switches just mentioned. Probably the most popular and useful of the switches are motion sensors that have a timer. Motion sensors need to be capable of “seeing” the surroundings, so the sensor is preferably mounted in or adjacent the light. Adding a recess into an acrylic brick light that accepts a sensor would be ideal. The sensor can be adjusted for a desired sensitivity and coverage area by accessing the back of the light when it is tilted well beyond ninety degrees. The sensor is typically electrically connected between the light source and a rechargeable battery.
A rechargeable battery is the power supply for a light. Most solar panels that could be used with a solar light assembly are designed for 12 volt systems, so a 12 volt battery should be used. A 100 Amp hour or larger sealed maintenance-free lead-acid battery would be suitable for dusk to dawn applications. When such a large battery is used with a system of the present invention, it is only recommended to locate the battery remotely rather than attempting to install the battery into a housing. A system controller 46 should be electrically connected between the rechargeable battery and the solar panel. A system controller with a built in low voltage disconnect device will protect the battery from excessive charge or discharge. Morningstar Corporation, Washington Crossing, Pa., offers simple 12 volt system controllers, such as their SunLight™ models, which are ideally suited for solar light assembly applications. As already discussed, the system controller can be housed inside the housing so it can be easily accessed for service or replacement.
A pole 80 used to mount the solar light assembly several meters above ground level can be any common pole, such as four inch rectangular steel tubing. Any known method for erecting a pole and running wiring up the pole can be implemented. Brackets and/or other mounting hardware, not shown, may be required to properly secure the frame to the pole.
In
In
The second preferred embodiment has three basic configurations, shown in
An advantage of the second preferred embodiment is the ability to interchange parts. The same pole 80, frame 30 and solar panel 20 can be used with any of the three shown configurations without needing to modify anything except the slope at the top of the pole. The holes 36 in the frame that accept the housings 40 are preferably square. There is no slope associated with the housings used in
For even greater versatility, but arguably less aesthetic, sloped housings can be used with a flat mounted solar panel, or housings not having a slope can be used with a postured solar panel. Along those lines, there are numerous less conventional-looking configurations for more expressive people. For configurations that do not keep the face of a housing in a horizontal plane, additional fasteners may be required to prevent a light from shifting. If desired, a small motor or solenoid could be used to adjust the tilt of the light such that the light is only tilted into a desired position at night, when the light is on, but then recessed back into the housing during the daytime.
While a preferred form of the invention has been shown and described, it will be realized that alterations and modifications may be made thereto without departing from the scope of the following claims. For example, while the slope of the various postured frames and solar panels shown in the drawings is about thirty degrees, that slope was somewhat arbitrarily selected, but it represents a compromise between efficiency, aesthetics and vandalism prevention. A steeper slope is more efficient in the United States, but vandalism becomes more likely and the solar panel becomes more visually offensive as the slant increases.
This application claims the benefit of priority of U.S. Provisional Application No. 61/269,679, filed on Jun. 29, 2009, and titled “Solar Light Assembly for Street and Park Lighting”, incorporated herein by reference in its entirety.
Number | Date | Country | |
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61269679 | Jun 2009 | US |