1. Technical Field of the Invention
Our present invention pertains to a photovoltaic illuminating device for a street address number on a roadside mailbox. In particular, the stand-alone device can be easily installed onto an existing mailbox or its post. It employs one thin-plate solar cell to absorb solar energy during daytime, and one or two light-emitting diodes (LED) to shed light to address numerals during nighttime.
2. Description of Prior Art
In US, Canada and other countries, the address number sign of a residential house is often labeled on the mailbox or its supporting post alongside the street in front of the house. It is a common experience that, in the evening and during nighttime, locating a specific address in a dark or poorly lighted neighborhood is oftentimes a difficult job. Fire departments across America all agree that one of their most difficult tasks in their nighttime emergency operations is to figure out which house the call has come from. Our present invention has been developed to solve this problem.
Our reference search has revealed a few patented solar energy devices and related applications that intended to provide illuminating help for signs and other residential uses. Solar-powered illuminated mailbox address signs are disclosed in U.S. Pat. Nos. 5,460,325 and 5,522,540 to Surman, and U.S. Pat. No. 6,076,294 to Durbin.
U.S. Pat. No. 5,522,540, as a Continuation-In-Part of U.S. Pat. No. 5,460,325, discloses an illuminated mailbox address assembly, and describes the mailbox structure changes required for installing the assembly. In brief, the referenced patent would require a homeowner either to adopt a new mailbox structure (for rural type mailbox) or to reconstruct an existing mailbox (for urban type mailbox) in order to install the illuminated address number assembly. In other word, replacing and restructuring the existing mailbox would be necessary for using the referenced patent.
U.S. Pat. No. 6,076,294 discloses a solar-powered illuminated mailbox address plate which can be attached to one side of a mailbox. The referenced patent uses one light-emitting diode (LED) for each indicium (or digit). Thus, for an address number sign with 4 indicia, four LEDs will be used. If two address plates are needed for both side of the mailbox, 8 LEDs will be needed. The referenced patent uses a solar panel and a rechargeable lead-acid battery to provide power for illuminating.
Therefore, it is desirable to create a stand-alone device that uses a minimum number of LEDs, so that the device (1) allows easy installation on an existing roadside mailbox without any structural change of the mailbox itself, (2) is energy-saving and in a compact form, and (3) is practically and commercially doable and affordable. Our present invention presents such a device that does not require replacement or reconstruction of the existing mailbox. A homeowner can install this device easily at any convenient position on an existing mailbox or its supporting post.
Generally, as provided by this invention, a photovoltaic illuminating device consists of a commercially available thin-plate solar cell, a printed circuit board (PCB), one or two rechargeable batteries, a lighting means, and an address display means. The solar cell, the PCB and the rechargeable batteries are assembled closely together within an assembly enclosure, while the lighting means and the address display means can be either separated from or integrated with the assembly enclosure.
The solar cell is placed at the top of the assembly enclosure. The PCB and the rechargeable batteries are below the solar cell and within the enclosure. During daytime, the solar cell collects and converts the solar energy to electrical energy, and charges the rechargeable batteries through the PCB. When the evening comes or the ambient light becomes insufficient to see the address number, the charged batteries discharge the electrical energy to power the lighting means to illuminate the address number. A photo sensor, connected to the PCB and integrated at the edge of the solar cell plate, controls the PCB to charge the batteries during daytime and to discharge the batteries to power the illuminating means during nighttime.
The enclosure is placed at the top of the mailbox or at the top the mailbox post, via adhesive means or mounting screws. Preferably, the enclosure is tilted to allow the solar cell to face the Sun's position around the noontime, thus, colleting the maximum amount of solar energy. For this purpose, the enclosure is installed on the mailbox post via two L-shaped brackets that allow two rotational adjustment of the solar cell orientation.
The lighting means, preferably a light-emitting diode (LED), is connected with the rechargeable batteries via an electrical extension wire, and is connected to an address display means. Preferably, an address display means is a hollow rectangular frame with each face being a diffuser plate (such as a semi-transparent plastic plate). An LED, electrically wired from the enclosure, is located inside one end of the frame and sheds light into the hollow frame. Preferably, another so-wired LED is installed at the opposite end of the frame and sheds light into the hollow frame from an opposite direction. Individual self-adhesive numerals (digits) stick to the outer face of each diffuser plate to form the address number. The rectangular frame is in horizontal or vertical position and is attached to the mailbox or fixed to the side of the post. Preferably, the display frame stays horizontal and is placed on the top of the mailbox. Preferably, further, the afore-mentioned assembly enclosure and the display frame are integrated together to become one solid single unit that is then placed horizontally at the top of the mailbox or attached vertically to the mailbox post.
Preferably, optical fiber panels are used in the hollow space within the display frame and between the two diffuser plates. Light-emitting diodes are used to serve as light sources for the optical fiber panels. Advantage of using optical fiber panels is to provide a uniform lighting background for the address numerals on the diffuser plates.
Besides the intended use of the invention, which is to provide aid for visitors to identify street addresses on mailboxes, the illuminating device immediately adds a pleasant and impressive nighttime landscaping feature to any residential neighborhood.
The present invention and its preferred embodiment are described in detail in this section with reference to
As shown in
A preferred form of the display frame is shown in
Preferably, optical fiber panels 26, are used in the hollow space of the display frame 4, between two diffuser plates 21, as shown in
Alternatively, the address display frame 4 takes a vertical position with address numerals 22 being aligned vertically, as showed in
As shown in
An integrated one-unit device is mounted on the top of an existing mailbox 1 with mounting screws 19, as shown in
It is understood that alternative forms and arrangements of this invention, other than those described herein, exist. Such alternative forms and arrangements may be made without departing from the scope and spirit of this invention.
This application claims priority from US Provisional Application Ser. No. 60/531,272, filed on Dec. 22, 2003, and the contents of which is incorporated herein by reference in its entirety.
Number | Date | Country | |
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60531272 | Dec 2003 | US |