Patent Application
20110222291
This invention relates generally to lighting fixtures for commercial and residential applications, and in particular, to a lighting fixture that includes an integrated junction-box (commonly referred to also as a J-box).
Lighting fixtures used in commercial and residential applications are typically mounted on the ceiling, although some fixtures are mounted on the walls as well. These lighting fixtures usually require at least two wires to supply electrical power to the light source. Typically, in commercial and residential applications, it is required that all electrical wiring for a lighting fixture must be routed through a junction-box (J-box) that is assigned to that particular lighting fixture. This is better explained with reference to the following example.
The first electrical wiring set 106 may be routed to a J-box 108 that is designated to lighting fixture 102. A second set of electrical wiring 110, which is electrically connected to the first set 106 via the J-box 108, is routed from the J-box 108 to the lighting fixture 102. A third set of electrical wiring 112, which is also electrically connected to the first set 106, is routed from the J-box 108 to another J-box 118 that is designated for lighting fixture 104. A fourth set of electrical wiring 116, which is electrically connected to the first set 106 via the J-boxes 118 and 106, is routed from the J-box 118 to the lighting fixture 104.
The lighting fixture electrical network 100 is merely an example, and it shall be understood, that the network may vary extensively. However, as noted in this example, the electrical network 100 is relatively complex. This is because electrical wiring for each lighting fixture must be routed by way of a separate J-box. This requirement generally presents lots of drawbacks. For instance, the wiring is complex, for example, requiring four sets of electrical wirings for two lighting fixtures. This typically results in substantial amount of labor to properly wire the lighting fixtures, and consequently translates to higher costs. Additionally, the complexity of the wiring may lead to electrical reliability problems.
An aspect of the invention relates to a lighting fixture that includes an integrated junction box. The integrated junction box substantially simplifies the electrical wiring of one or more of such lighting fixtures in a commercial or residential setting. This is because the lighting fixture eliminates the need to route wires from a separate junction box to the fixture. The reduction in the complexity of the electrical wiring translates to reduced labor, time, and expense in the installation of such lighting fixtures. Additionally, the reliability of the lighting fixtures and its electrical wiring network is substantially improved.
In particular, the lighting fixture may comprise a light source (e.g., a light emitting diode (LED) based light source), a housing enclosing the light source, and a junction box mechanically coupled to or integrated with the housing. The lighting fixture may further comprise a ballast adapted to generate a drive signal for the light source. In another aspect, at least a portion of the ballast is situated within the junction box. For thermal control, the lighting fixture may also include a heat sink thermally coupled to the light source, and a plurality of cooling fins thermally coupled to the heat sink.
In another aspect, the lighting fixture may comprise one or more diffusers for scattering the light at distinct locations within the fixture; a reflector adapted to guide and focus the scattered light towards an emitting end of the lighting fixture; a lens situated optically between the second diffuser and the emitting end; and a trim situated around the perimeter of the lens. In another aspect, the trim and the reflector may be an integrated element. In yet another aspect, a support ring may be coupled to a lower end of the housing, and used to secure the fixture onto a support member (e.g., a ceiling). In still another aspect, the support ring includes a first coupling member, and the trim includes a second coupling member. The first and second coupling members are adapted to be securely mated by rotating the trim relative to the support ring.
In another aspect, the lighting fixture housing comprises a plurality of swivelable clamps, wherein the clamps and the support ring are configured to clamp to the support member to secure the fixture on the member. In yet another aspect, the swivelable clamps are adapted to be in an extended position to secure the fixture onto the support member. In still another aspect, the swivelable clamps are adapted to be in a retracted position to allow at least a portion of the fixture housing to be inserted through an opening in the support member.
In another aspect, the junction box operates at least in part as a heat sink to more efficiently remove heat away from the light source and associated electronics (e.g., a ballast). This reduces the operating temperature of the light source and associated electronics, which enhances the reliability of the lighting fixture.
Other aspects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.
In particular, the lighting fixture 200 comprises a main housing 202 for housing many components of the fixture, as discussed in more detail below. The main housing 202 may be configured to have a plurality of vertically-oriented cooling fins 204 in order to efficiently dissipate heat generated by the light source and related electronics. The main housing 202 may further include a plurality of swivelable clamps 206 for securely attaching the lighting fixture to a support member, such as a ceiling, as discussed in more detail below. The clamps 206 may be substantially equally spaced around the circumference of the cone-shaped housing 202. In this example, the main housing 202 includes three clamps 206 (only two being shown in
Each swivelable clamp 206 includes a vertical member 207 having an edge portion situated longitudinally within a vertically-oriented groove 214 of the main housing 202. The clamp 206 is configured to be moved vertically along the groove 214, and also rotate about the longitudinal axis of the groove. Each clamp 206 includes a horizontal flange 208 attached to the lower portion of the vertical member 207. When the clamp 206 is situated in its lowest position along the groove 214, the flange 208 makes contact with a support ring 220 of the lighting fixture 200, and ensures that the clamp extends substantially radially outward from the main housing 202 (e.g., the clamp's extended position). When the clamp 206 is in its highest position along the groove 214, the clamp is able to rotate such that the flange 208 is disposed on a ledge 212 of the main housing 202 (e.g., the clamp's retracted position).
The support ring 220 includes a vertical portion 222 that extends below the lower portion of the cone-shaped main housing 202. Additionally, the support ring 220 includes a horizontal portion 224 that extends radially outward from the lower end of the vertical portion 222 of the support ring. As discussed in more detail below, the lighting fixture 200 is secured to the ceiling by the lower side of the ceiling resting on the horizontal portion 224 of the support ring 220, and the flanges 208 of the clamps 206 resting on the upper side of the ceiling when the clamps are in their extended position. In other words, the flanges 208 and horizontal portion 224 clamp onto the ceiling.
As discussed above, the lighting fixture 200 further includes a J-box 216 that is integrated or mechanically coupled to the main housing 202. More specifically, an upper portion of the main housing 202 includes a square or rectangular shaped opening. The square- or rectangular J-box is situated over and aligned with the opening. As shown, the J-box 216 further includes a removable cover 218 to allow access to the inside of the J-box for electrical wiring purpose, and to cover the J-box during normal use, handling, and transportation. Additionally, the cover 218 may include one or more openings or ports 219 through which electrical wiring may extend. As discussed in more detail below, the J-box further houses at least a portion of a ballast that drives the light source of the lighting fixture 200. The integrated J-box may further be used as the heat sink for the ballast and light source.
As shown, the J-box 216 houses at least a portion of the ballast 230, as well as the electrical wiring (not shown) typically housed in a J-box. The power PCB 231 of the ballast 230 generates a drive signal for the light source 236. The heat sink 232 is thermally coupled to the light source PCB 234 to assists in removing heat from the light source 236. Additionally, the heat sink 232 may be thermally coupled to the cooling fins 204 and the J-box 216 to improve the thermal control of the lighting fixture 200. The light source 236, which is mounted on the PCB 234, and may be LED based, generates the light of the lighting fixture 200. The reflector 238 assists in guiding and focusing the light downward towards the emitting end of the fixture 200. The diffuser lens 242 further scatters the light exiting the reflector 238. The lens 244 guides the light emanating from the fixture 200, as well as provides a decorative cover for the internal components of the fixture. The trim 240 provides a decorative trim around the lens 244.
The light source 706 generates the light based on the drive signal. The reflector 710 guides and focuses the light towards the emitting end of the lighting fixture 700. The light diffuser 712 performs a scattering of the light near the emitting end of the lighting fixture 700. And, the lens 714 guides the light, while at the same time provides a decorative cover to protect the internal components of the lighting fixture 700.
While the invention has been described in connection with various embodiments, it will be understood that the invention is capable of further modifications. This application is intended to cover any variations, uses or adaptation of the invention following, in general, the principles of the invention, and including such departures from the present disclosure as come within the known and customary practice within the art to which the invention pertains.
