The present invention relates generally to light fixtures and specifically to outdoor light fixtures which are exposed to the environment and are utilized as floodlights or spotlights to accent buildings and other structures.
Outdoor light fixtures are utilized for a variety of purposes, such as spotlights or floodlights to illuminate a chosen area or to accent a building or some other structure. For example, outdoor light fixtures are used around houses to shine generally on the front facade of the house and thereby accent the architectural features of the house. Outdoor lights are also utilized at the base of trees, flagpoles and other environmental structures, to illuminate and accent the structures for decorative purposes. Such lighting is often referred to as uplighting. Outdoor light fixtures are also utilized to illuminate more remote areas for the purpose of safety.
Outdoor light fixtures are exposed to the environment due to their usage. Therefore, such fixtures are generally constructed to withstand moisture, such as dew, rain, or water from a sprinkler system. The construction of an outdoor light fixture generally comprises a partially closed housing, open at one end. The housing holds a lamp bulb which shines a beam out of the open end of the housing onto the illuminated structure. In some fixtures, a transparent glass lens is placed over the open end of the housing to close and seal the housing such that water and moisture cannot enter and affect the operation of the lamp. While various available light structures are sealed to keep water from entering, and do so adequately, they have other drawbacks.
For example, many existing light fixtures utilize circular sealing rings which surround the periphery of the open end of the light fixture housing. The sealing rings are utilized in conjunction with circular gaskets. A peripheral lip is formed around the open end of the housing and the circular sealing ring is bolted to the front lip of the housing with bolts which extend generally perpendicular to the lens plane or sealing plane. The gasket is captured between the sealing ring and the housing to seal the housing. Utilizing such sealing rings around the periphery of the housing increases the outer diameter of the open end or front end of the light fixture. The larger front end profile of the fixture is not particularly aesthetically appealing. Since outdoor light fixtures are often visible, and a particular installation may utilize a large number of such fixtures, the aesthetic effect of the light fixture is a relevant consideration.
Furthermore, such peripheral sealing designs increase the manufacturing costs of the light fixture by increasing the number of precision machined parts which must be properly seated in order for the fixture to withstand the exposure to rain, dew, or sprinkler water. Furthermore, the construction and installation of such light fixtures is generally more complicated because of the required alignment between the various sealing, gasket, and housing lip elements.
Accordingly, there is a need in the art for-an aesthetically pleasing outdoor light fixture which is more streamlined and smaller in profile than existing fixtures and which effectively prevents large amounts of moisture from entering the fixture housing.
There is a further need in the art to provide a durable, outdoor light fixture which addresses the above need for a water-resistant light fixture and is relatively inexpensive to manufacture.
There is still a further need in the art for an uncomplicated outdoor light fixture which is readily constructed and installed without requiring tedious alignments between the various elements of the fixture.
The aforementioned needs in the prior art are addressed by the present invention which comprises a light fixture use comprising a housing that defines an interior space therein. The housing has an open end with a sealing face and the interior space is configured to contain a lamp bulb to shine a beam out of the open end of the housing. A retention ring is configured for surrounding the housing open end and is axially movable with respect to the housing and along the length of the housing. The retention ring includes a retention surface configured to oppose the sealing face of the housing. A transparent lens, for example a flat lens or a convex lens, is configured to fit over the open end of the housing to close the housing while allowing a portion of the light beam to pass therethrough. The lens has an outer edge which is positionable between the sealing face of the housing and the retention surface of the retention ring to secure the lens to the housing and thereby seal the housing.
A radial groove is formed in the housing proximate the housing open end. The radial groove may extend continuously around the housing or may comprise a plurality of end-to-end grooves in a non-continuous arrangement. The radial groove includes a cam surface configured to slope in an axial direction along the housing. In a preferred embodiment of the invention, the radial groove is positioned rearwardly of the housing sealing face and the cam surface slopes in a rearward axial direction. A cam following structure is coupled to the retention ring and is operable for engaging the radial groove cam surface and axially moving the retention ring to move the retention surface against the housing sealing face to capture the lens outer edge and thereby seal the housing.
In one embodiment of the invention, the cam following structure is a series of threaded bolts or screws which are positioned within threaded radial apertures around the retention ring. The threaded bolts thereby engage the groove at various positions around the open end of the housing. Each bolt has a portion which follows the cam surface of the groove and when the bolts are tightened or threaded into the radial apertures of the retention ring, they engage the cam surface and direct the retention ring axially along the housing. In that way, the retention surface of the retention ring is moved against the opposing sealing face of the housing to capture the lens and thereby seal the housing with the lens.
In one embodiment of the invention, a seal is utilized around the outer peripheral edge of the lens and is compressed between the retention ring, retention surface, the lens, and the sealing face of the housing. For example, a seal having a U-shaped cross section may be utilized around the edge of the lens and will provide a seal portion which is coupled between the retention surface and the lens, and also a portion which is coupled between the lens and the sealing face. Furthermore, a portion of the seal is also coupled between an annular surface of the lens and another surface of the retention ring to provide a complete seal around the edge of the open end of the housing to deter and generally prevent water or moisture from entering into the open end of the sealed housing.
As another feature of the invention, a flexible diaphragm surrounds the base of the bulb and is mounted on a ring which is fitted into a groove inside the housing. Apertures are positioned proximate the groove such that moisture is directed away from the bulb by the diaphragm and is drained out of the housing through the apertures. In that way, the light fixture is further protected from the elements and might also be used without a lens or seal with a suitable weather-resistant bulb, such as a PAR bulb.