Patent Application
20170292693
The present invention relates to light fixtures and in particular to a moisture sealed light fixture.
Lighting fixtures used in wet areas are preferably sealed to prevent moisture from entering the fixture and corroding exposed electrical elements. For example, U.S. Pat. No. 2,813,9780 for “Lighting Unit” discloses a wet area light fixtures including a shade 41 held (or sandwiched) between a canopy 10 and a flange 14. Two gaskets 46 and 50 sandwich the light shade 41 presenting two failure modes, one for each gasket. Further, the gaskets 46 and 50 are both exposed to the elements, accelerating their potential for failure in harsh environments. When one of the gaskets fails, moisture can enter a wiring cavity of the lighting fixture resulting in corrosion and ultimately failure. The gradual corrosion may further increase resistance between electrical connections in the wiring cavity creating heat and a potential risk of fire.
The present invention addresses the above and other needs by providing a Cast Guard Unit (CGU) light fixture which is suitable for dry and wet areas and seals a wiring cavity using a single O-Ring. A cylindrical projection of the CGU center telescopingly engages a cylindrical cavity in the CGU top to varying depth and flanges on the CGU center and CGU top sandwich a light shade. The engagement of the cylindrical projection into the cylindrical cavity is free to vary to accommodate varying thicknesses of various light shades. The O-Ring resides between the cylindrical projection and the cylindrical cavity sealing the wiring cavity.
In accordance with one aspect of the invention, there is provided a CGU light fixture accommodating varying thickness light shades. The CGU light fixture includes a telescoping engagement of the CGU center and CGU top providing a sealed wiring cavity regardless of the thickness of the light shade.
In accordance with one aspect of the invention, there is provided a CGU light fixture sealed by a single O-Ring. The O-Ring resides between the cylindrical projection and the cylindrical cavity sealing the wiring cavity.
The above and other aspects, features and advantages of the present invention will be more apparent from the following more particular description thereof, presented in conjunction with the following drawings wherein:
Corresponding reference characters indicate corresponding components throughout the several views of the drawings.
The following description is of the best mode presently contemplated for carrying out the invention. This description is not to be taken in a limiting sense, but is made merely for the purpose of describing one or more preferred embodiments of the invention. The scope of the invention should be determined with reference to the claims.
Where the terms “about” or “generally” are associated with an element of the invention, it is intended to describe a feature's appearance to the human eye or human perception, and not a precise measurement.
A Cast Guard Unit (CGU) top 12, A CGU center 14, a light guard 16, and a glass light enclosure 24 are shown in
Across-sectional view of the CGU top 12 and CGU center 14 taken along line 3-3 of
The upward reaching cylindrical projection 30 has a height H1 and the O-Ring groove 22a is a height H2 above the flange 36. The height H1 is preferably between ¼ and ½ inches, and more preferably about 0.35 inches. The height H2 is preferably between 0.15 and 0.25 inches and more preferably at least 0.2 inches and most preferably about 0.2 inches.
The CGU top 12, CGU center 14, and light shade 18 shown before assembling in
The CGU top 12 and center 14 separated, and a portion of the light shade 18, are shown in
A third CGU top 12c and the center 14 are shown separated in
While the invention herein disclosed has been described by means of specific embodiments and applications thereof, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope of the invention set forth in the claims.
