The present invention pertains generally to lighting fixtures and, more particularly, to lighting fixtures to be installed in suspended or false ceilings and methods for installing such lighting fixtures.
Suspended ceilings, sometimes also known as false ceilings, are very common features of commercial, retail and many other buildings. A suspended ceiling is formed of a grid that is suspended from a permanent ceiling or structure and ceiling tiles supported by the grid. The suspended ceiling grid is formed of a series of beam structures having a cross-section in the shape of an inverted T, i.e., having a vertical rib and two horizontal flanges extending from the bottom of the vertical rib along the length of the beam. Hereinafter these grid pieces will be referred to as T-bars. The T-bars forming the suspended ceiling grid are suspended from the permanent ceiling above via wires or other structures. (Along the walls of a room in which a suspended ceiling is installed the beam structures employed have an L-shaped cross section, i.e., having a vertical rib portion that is attached to the wall and a horizontal flange portion extending from the vertical rib portion along the length thereof into the room.) The T-bars forming the suspended ceiling are laid out to define a grid of square or rectangular openings between the T-bars. The openings typically are 2 feet by 2 feet square or 2 feet by 4 feet in size (although other sized openings also may be defined). Ceiling tiles of the appropriate size are placed in the openings and supported along their edges by the horizontal flanges of the T-bars forming the suspended ceiling grid to complete the suspended ceiling. The ceiling tiles, also known as acoustical tiles, typically are made of a generally sound and heat insulating material, such as foam or the like, with a lower surface, that is visible to those in the room below the ceiling, decoratively formed. The space between the suspended ceiling thus formed by the T-bar grid and ceiling tiles and the permanent ceiling structure forms a convenient space for running various utilities, such as heating, ventilation and air conditioning ducts, electrical wiring, etc. The suspended ceiling hides these utilities from view while also allowing access thereto, by removing ceiling tiles and/or pieces of the T-bar grid from the suspended ceiling, for servicing when necessary.
Besides the ceiling tiles, the suspended ceiling grid also is used to support various other structures and devices, such as lighting fixtures, heating, ventilation and air conditioning vents, fire and smoke alarms, motion detectors, etc. These structures and devices may be attached to and/or supported by the suspended ceiling grid so as to extend at least partially below the suspended ceiling into the room below or may be entirely recessed above the plane of the suspended ceiling grid. Electrical and other connections for such structures and devices typically are formed in the space between the suspended ceiling and the permanent ceiling structure from which it is suspended so as not to be visible in the room below.
Perhaps the most common structures and devices, other than ceiling tiles, to be supported by a suspended ceiling grid are lighting fixtures. Over the years many different types of lighting fixtures have been developed for use in suspended ceilings and many structures and methods have been developed for attaching such fixtures to the suspended ceiling T-bar grid. A typical lighting fixture for use in a suspended ceiling includes a box like structure, sometimes called a troffer, having end and side walls, a top reflector closing one end of the end and side walls, and an open side opposite the top reflector. Lamps, such as fluorescent lamps, typically may be mounted within or suspended from the fixture box. Often the open side of the fixture box may be covered by a hinged or otherwise removable lens or louver, that disburses the light from the lamps but that can be easily removed to replace the lamps when necessary. Electrical connections for the fixture, including, typically, the fluorescent lamp ballast, typically are provided on the top of the top reflector, so as not to be visible from below when the lighting fixture is installed in a suspended ceiling.
Lighting fixtures of the type described typically are sized and designed such that they may be supported in the openings in a suspended ceiling grid along the bottom edges of the end and side walls thereof that are placed on the horizontal flanges of the T-bars surrounding the opening. Clamps or other structures often are used to secure the lighting fixture in position to the ceiling grid T-bars. Actually placing the lighting fixture in position within the T-bar grid can, however, prove to be a challenge. If the installer has access from above the suspended ceiling he can lower the lighting fixture into position on the T-bar grid from above. This, however, rarely is the case, as the space between the suspended ceiling grid and the permanent ceiling structure above typically does not provide enough room or access to allow the lighting fixture to be lowered into the suspended ceiling grid from above. The other option is to lift the lighting fixture into position from below. However, manipulating a lighting fixture that is several feet across through a suspended ceiling grid and into position from below is very cumbersome and often difficult.
One common solution to the problem of installing a lighting fixture as a substantially single piece in a suspended ceiling has been to provide a lighting fixture in several pieces that are assembled in position in the suspended ceiling to form the lighting fixture. Individual smaller pieces forming the lighting fixture are more easily moved into position in the suspended ceiling grid from below than an entire lighting fixture several feet across. Many such lighting fixtures that may be assembled in place in a suspended ceiling grid in this manner have been developed. However, none of the known solutions has proved entirely successful. Most such solutions require that many lighting fixture pieces be assembled together in a suspended ceiling grid using various fasteners and tools. As anyone who has done so can testify, manipulating many pieces, fasteners and tools while working over one's head is difficult, uncomfortable, and time consuming.
What is desired, therefore, is an improved lighting fixture for a suspended ceiling that can be mounted in a suspended ceiling from below the ceiling easily and quickly. Preferably, the lighting fixture can be assembled from a minimal number of pieces that can be installed in place in a suspended ceiling grid without requiring the manipulation of tools or fasteners.
The present invention provides a lighting fixture that may be easily and securely installed in a suspended ceiling from below the ceiling. The lighting fixture may comprise only four separate pieces to be installed, two end caps, a reflector assembly, and a ballast box cover. The two end caps are first slid into position at opposite ends of an opening in a suspended ceiling formed of a T-bar grid. The end caps are supported in position by the T-bar grid. The reflector assembly may be temporarily suspended from the end caps so that electrical connections to the assembly made and the ballast box cover installed. The entire reflector assembly may then easily be lifted into position into the suspended ceiling to be supported by the end caps mounted therein.
Each of the end cap pieces of a lighting fixture in accordance with the present invention may include a main plate portion including an inner surface and an outer surface, a top edge, and a bottom edge. A bottom flange extends outward toward the outer surface of the main plate portion from the bottom edge thereof and is adapted to rest on the horizontal flanges of the T-bar supports of a suspended ceiling in which the lighting fixture is installed. Mounting brackets extend inward from each end of the bottom edge of each plate portion and also are adapted to rest on the horizontal flanges of the T-bar supports. Each of the mounting brackets may include a plurality of bendable tabs extending substantially vertically upward from the mounting brackets. The bendable tabs are of different lengths, such that at least one of the plurality of bendable tabs on each mounting bracket is adapted to engage the vertical ribs of the T-bar supports of a suspended ceiling in which the end cap pieces are installed when the bendable tab is bent outward from the vertical position toward the vertical rib of the T-bar support. Each of the end cap pieces may also include a top flange extending inward from the top edge thereof and each of the mounting brackets may include at least one support tab extending inward therefrom approximately parallel with the inner surface of the main plate.
The reflector of a lighting fixture in accordance with the present invention may include a preferably curved reflector plate portion having an outer surface and an inner surface. A vertical flange portion extending upward along the non-curved edges of the reflector plate have mounting tabs formed therein that are adapted to engage the support tabs extending from the mounting brackets of the end caps. Support tabs extending from the other sides of the reflector are positioned thereon to engage the top flanges of the end cap pieces. These support tabs may extend from a ballast box portion of the reflector mounted on the outer surface of the reflector plate. A removable cover may be provided for the ballast box, and a lamp enclosure may be mounted on the outer surface of the reflector plate.
The end cap pieces may include shaped side edges including notches formed therein. Tabs extending from the ends of the non-curved edges of the reflector plate may be adapted to engage these notches to temporarily suspend the reflector from the installed end cap pieces while electrical connections are made to the reflector.
Further objects, features, and advantages of the present invention will be apparent from the following detailed description taken in conjunction with the accompanying drawings.
An exemplary lighting fixture in accordance with the present invention first will be described in detail herein, followed by a detailed description of a method for installing such a lighting fixture in a suspended ceiling. An exemplary lighting fixture 30 in accordance with the present invention for installation in a suspended ceiling 32 is illustrated in, and will be described in detail first with reference to,
A lighting fixture in accordance with the present invention preferably has a minimal number of pieces that may be assembled in place in a suspended ceiling. As illustrated in
Exemplary end caps 44 for a lighting fixture 30 in accordance with the present invention are illustrated in detail in
A mounting bracket 70 is provided extending at a right angle from each end of the plate portion 52 of the end cap 44 adjacent to the bottom edge 60 thereof. The mounting bracket 70 extends inward from the ends of the plate portion 52, i.e., toward the inner surface 54 thereof. A plurality of bendable tabs 72 of varying height preferably are formed extending upward from the mounting bracket 70 along the length thereof extending perpendicular to the plate portion. As will be discussed in more detail below, during installation of a lighting fixture 30 in accordance with the present invention, one of the bendable tabs is bent to support the end cap 44 in position in the suspended ceiling 32 in which it is being installed. One or more support tabs 74 are formed extending at a right angle from a distal end of the mounting bracket 70, i.e., from the end thereof opposite the plate portion 52 of the end cap 44. Thus, the support tabs 74 extend parallel with the plate portion 52 opposite the inner surface 54 thereof. As will be discussed in more detail below, the support tabs 74 are employed to support the reflector piece 46 in position in a suspended ceiling via the end caps 44 mounted therein.
A reflector 46 of a lighting fixture 30 in accordance with the present invention may include three major components: a reflector plate 76, a ballast box 78, and a lamp enclosure 80. Note that preferably each of these components are combined into a single piece by the lighting fixture manufacturer so that they may be installed as a single reflector 46, as described above, when the lighting fixture 30 is installed in a suspended ceiling 32. For completeness, and ease of illustration and description, however, each of these component parts now will be described in more detail separately.
As illustrated in
As illustrated in
The ballast box 78 is designed to contain the fluorescent lamp ballast and other electrical components required by a fluorescent lighting fixture 30 in accordance with the present invention. Electrical power is provided to the lighting fixture 30 via, e.g., the power supply connection 50, to the ballast and other electrical components contained in the ballast box 78. One or more conventional break-away or break-out portions 98 may be provided in one or more side walls of the ballast box 78 (and/or in the cover 48), to provide access by the power supply connection to the interior of the ballast box 78. A conventional wiring, cable, or conduit connector 100 may be mounted in one or more of these break-outs 98 to provide for connecting the power supply connection 50 to the ballast box 78. The type of connector 100 to be employed will depend upon the type of wiring or other electrical conduit forming the power supply connection 50. One or more apertures, such as threaded conduits 101, may be formed and/or provided through a bottom surface of the ballast box 78 to provide for the extension of electrical wiring therefrom to the fluorescent lamp or lamps mounted in the lamp enclosure 80 to be described in more detail below.
The ballast box 78 is mounted to the outer surface 84 of the reflector plate portion 76 of the reflector 46. As illustrated, the ballast box 78 may be mounted to the outer surface of the reflector plate 76 at the center of the curvature thereof and extending along the non-curved length thereof. Any conventional method may be used to mount the ballast box 78 to the outer surface 84 of the reflector plate. For example, appropriate fasteners may be extended from the bottom of the ballast box 78 through the mounting holes 86 formed in the reflector plate 76 to mount the ballast box 78 to the reflector plate 76. As will be described in more detail below, the threaded conduits 101 on the ballast box 78 may be extended through the mounting holes 86 formed in the reflector plate 76 to which the lamp enclosure 80 then is attached thereby to mount both the ballast box 78 and the lamp enclosure 80 to the reflector plate 78.
The ballast box 78 preferably is dimensioned to be approximately as long as the reflector plate 76 to which it is mounted. Support tabs 102 or another similar structure preferably are formed extending from each end of the ballast box, such that the support tabs 102 extend from the ballast box 78 in the direction of the non-curved direction of the reflector plate. As illustrated, the support tabs 102 or other similar structure preferably extend slightly downwardly, in the direction of the reflector plate 76, as they extend from the ballast box 78, to provide a somewhat hook shaped structure. Preferably these tabs may be formed at or near each corner of the ballast box 78. As illustrated, preferably multiple, e.g., two, such support tabs 102 are provided, one above the other, at each of the four corners of the ballast box 78. The providing of multiple rows of support tabs 102 in this manner provides for use of a single lighting fixture 30 in accordance with the present invention in different types of suspended ceilings 32. As also will be discussed in more detail below, during installation of a lighting fixture 30 in accordance with the present invention in a suspended ceiling 32, the support tabs 102 extending from the ballast box 78 interact with the top flanges 64 of the end caps 44 to support the reflector 46 in position in the suspended ceiling 32 via the end caps 44 already mounted therein.
An exemplary lamp enclosure 80 portion of a reflector 46 of a lamp fixture 30 in accordance with the present invention is illustrated in
An exemplary method for installing a lighting fixture 30 in accordance with the present invention in a suspended ceiling now will be described in detail. The preferred method of installation begins by installing two end caps 44 in position in an opening 40 formed by T-bars 34 of the suspended ceiling 32 at opposite ends of the opening. Before sliding the end caps 44 in position in the ceiling 32, one of the vertically extending support tabs 72 formed on the end caps is selected and bent outward slightly, e.g., about one-quarter inch. As illustrated in
In an alternative embodiment of the present invention, the tabs 72 provided on the end caps 44 may be made of a flexible material, such as spring steel, with all of the tabs 72 bent outward slightly before installation of the end caps 44 in a suspended ceiling 32. In this case, as the end cap 44 is installed in the ceiling 32 the flexible tabs 72 will be bent back inward as they contact the vertical portion 36 and spar 116 of the T-bar 34 against which they are being installed. At least one such flexible tab 72 at each end of the end cap 44, however, will remain bent outward slightly to engage the vertical portion 36 and spar 116 of the T-bar 34 to hold the end cap 44 in the desired position in the suspended ceiling 32. In this embodiment of the present invention, all of the flexible tabs 72 may come from the manufacturer ready to install in the slightly bent outward condition. Thus, the installer need not select and bend out a selected one of the tabs 72 prior to installation. It should be noted that, in this embodiment, only the portion of the end caps 44 including the support tabs 72 need be made of the flexible spring steel material. However, any such portion of, or the entire, end cap 44 may be made of such an appropriate material.
To connect the electrical power source 50 to the lighting fixture 30, the reflector 46 may be lifted in position and suspended from the end caps 44 mounted in the ceiling 32 temporarily, e.g., by positioning two of the tabs 94 at each end of one side of the reflector plate 76 portion of the reflector in the notches 63 provided for this purpose in the angled edge 62 of the opposed end caps 44. With the reflector 46 hanging in position and with the cover 48 removed, the electrical power source 50 can easily be connected to the ballast box 78 portion of the reflector, the appropriate electrical connections to the power source 50 made within the ballast box 78, and the cover 48 attached to the ballast box 78, e.g., using the fasteners 96 to close the ballast box 78.
Once the required electrical connections are completed and the cover 48 is in place, the entire reflector 46 may be mounted in position on the end caps 44. As illustrated in
It should be understood that the present invention is not limited by the particular exemplary applications and embodiments illustrated and described herein but embraces all such modified forms thereof as may come within the scope of the following claims.
This application claims the benefit of U.S. Provisional Patent Application No. 60/609,383, filed on Sep. 13, 2004.
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Number | Date | Country | |
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60609383 | Sep 2004 | US |