Patent Grant
8177385
The following invention relates to T-bars for use in supporting ceiling tiles within a suspended ceiling. More particularly, this invention relates to T-bars which include lighting supported therefrom, and particularly LED lighting, with the T-bar configured to include a heat sink for dissipating heat generated by the light source.
A common form of surface finish for ceilings, especially within commercial construction is the “dropped ceiling.” With a dropped ceiling a lattice of T-bars is suspended at a height desired for the ceiling. Ceiling tiles are provided which have a size and shape matching gaps in this lattice of T-bars. These ceiling tiles are placed within these gaps to fill these gaps between the T-bars. The T-bars generally have a shape with a vertically extending spine portion and a horizontally extending rest shelf so that the T-bar is generally in the form of an upside down “T.”
Lighting for interior building spaces can be provided in a variety of different ways. Often the most effective lighting for an interior space is overhead lighting. In a commercial environment where rooms are typically quite large, it is often advantageous to suspend lighting from the ceiling or embed lighting within the ceiling. When the ceiling includes a “dropped ceiling” arrangement, often some of the gaps in the lattice of T-bars are filled with lighting bays. For instance, fluorescent light tubes can reside within lighting bays that are sized to fill typical gaps within the T-bar lattice. Thus, rather than place a ceiling tile within certain gaps, lighting bays are installed.
An important consideration in the design and construction of buildings is the energy utilized by such buildings. One major factor in energy consumption of a building is the efficiency with which the space is heated and cooled. When the space utilizes a dropped ceiling, typically the conditioned space is only that space below the ceiling tiles of the“dropped ceiling.” Heating, ventilating and air conditioning (HVAC) ducts can be mounted in gaps between T-bars within the lattice forming the dropped ceiling in place of a ceiling tile, to deliver conditioned air into the conditioned space within the building. Space above the dropped ceiling typically has an undesirably hot or cold temperature compared to the conditioned space below. To enhance the effectiveness of HVAC systems in such buildings, ceiling tiles typically have a degree of resistance to heat transfer therethrough, such that temperature differentials between space above the dropped ceiling and conditioned space below the dropped ceiling can be efficiently maintained.
An additional source of power consumption within a building is the power consumed by lighting. Not only does lighting within a building directly affect energy consumption due to the power utilized to drive the light sources, but also lighting often generates significant heat within the conditioned space which then must be transferred from the space when the space is experiencing an unacceptably high temperature. Prior art attempts to reduce the energy consumption associated with lighting have included use of lower power higher efficiency lighting sources, such as fluorescent lighting and light emitting diode (LED) lighting. Beneficially, such alternative lighting sources both require less power to drive the light sources, and also typically generate less heat, minimizing heat sources which the HVAC systems of the building thus need to contend with. LED lighting also typically has a longer life than other lighting technologies.
One problem that is generated by utilization of LED lightings in particular, is that while a relatively low amount of heat is generated by the LED lighting, this heat is concentrated in a particularly small space directly adjacent the LED electronics required to generate the light. A major factor in the operating life of such LED lighting is the degree to which this heat can be effectively dissipated to avoid excessive heating of the electronics associated with the LED and other components of the LED which experience a shorter operational life when excess temperatures are experienced. Accordingly, a need exists for heat management associated with LED lighting, particularly when LED lighting is incorporated into a dropped ceiling of a building. Secondarily, other light sources and other sources of heat can benefit from having heat associated therewith transferred out of the conditioned space within a building, rather than the heat adding to the heat load within the conditioned space and requiring additional load on the HVAC equipment within the building.
With this invention, a T-bar is provided for a dropped ceiling which is configured to transfer heat effectively away from T-bar and ceiling mounted light sources and other heat sources, and into a space above a dropped ceiling. The T-bar can have any of a variety of different general cross-sections including a spine and a rest shelf at a lower end of the spine. Anchors are provided at terminal ends of the T-bar for attachment of ends of the T-bar within a conventional dropped ceiling system. For instance, the T-bar anchors can attach to adjacent T-bars or other supports in the forming of an entire lattice of T-bars within an existing conventional dropped ceiling system. A lower portion of the T-bar and beneath the rest shelf includes a light housing which can contain a lighting module therein. In a preferred form of this invention this lighting module includes at least one light emitting diode (LED) light source therein. An upper heat sink is coupled to the spine. This upper heat sink includes fins with gaps between the fins to enhance a rate of heat transfer between the heat sink and air adjacent the upper heat sink and above the ceiling tiles.
The T-bar preferably also includes a lower heat sink in the form of fins extending from the rest shelf. Preferably these fins include an outer fin and short fins closer to the spine than the outer fin. The outer fin is preferably longer than the short fins. In this way, an air pathway is provided from gaps between the fins of the lower heat sink and a ceiling tile resting upon the outer fin, for effective natural convection heat transfer away from the lower heat sink. The lower heat sink and light housing, as well as the spine and upper heat sink are preferably each formed together from a unitary mass of material to maximize heat transfer from the LED or other heat source to the heat sinks and then to the air within the space above the dropped ceiling. The entire T-bar is formed of a material having a higher than average thermal conductivity so that efficient heat transfer away from the LED or other heat source is accomplished.
A power supply for the LED is configured to be attachable to the upper heat sink so that a complete assembly for powering the LED lighting within the T-bar is suspended from the T-bar within the dropped ceiling system. By placing the lighting suspended from a lower surface of the T-bar, gaps within the T-bar lattice of the dropped ceiling system that would otherwise contain lighting can contain additional ceiling tiles to further enhance a resistance to heat transfer through the dropped ceiling to enhance an overall efficiency of the space conditioned by the HVAC system. Also, the aesthetic appearance of the ceiling can be enhanced by eliminating breaks in the ceiling for large prior art lighting bays. For instance, an entire ceiling of uniform ceiling panels can be provided, including the option to provide unique regular patterns, such as alternating colors in a checkered pattern.
Accordingly, a primary object of the present invention is to provide a T-bar which supports a light source on a lower side thereof and which includes a heat sink on an upper portion thereof to dissipate heat from the light source.
Another object of the present invention is to provide a T-bar with included heat dissipation structures to dissipate heat from a heat source adjacent a lower surface of the T-bar.
Another object of the present invention is to provide a method for drawing heat away from a light source on a lower portion of a T-bar of a dropped ceiling system.
Another object of the present invention is to provide a dropped ceiling system with T-bars that include lighting therein and associated heat dissipation structures for optimal lighting performance.
Another object of the present invention is to minimize energy utilized by a lighted building space.
Another object of the present invention is to provide lighting for a building space with a minimum power required.
Another object of the present invention is to provide a lighting system for a building space which is easy and inexpensive to install and which exhibits a long life.
Another object of the present invention is to provide a lighting system for a building which can easily be replaced and reconfigured.
Another object of the present invention is to provide an LED light source for mounting within a dropped ceiling of a building and which effectively dissipates heat from the LED light source for optimal service life.
Other further objects of the present invention will become apparent from a careful reading of the included drawing figures, the claims and detailed description of the invention.
Referring to the drawings, wherein like reference numerals represent like parts throughout the various drawing figures, reference numeral 10 is directed to a T-bar (
In essence, and with particular reference to
The T-bar 10 includes an upper heat sink 40 on an upper portion of the T-bar 10. This upper heat sink 40 is adapted to efficiently transfer heat away from the T-bar 10 to air surrounding upper portions of the T-bar 10. A lower portion of the T-bar 10 preferably supports a light housing 50. This light housing 50 is configured to be located below a dropped ceiling of which the T-bar 10 is a part, with the light housing 50 adapted to hold a lighting module 70 therein, such as a light emitting diode (LED) lighting module 70. Preferably, a lower heat sink 60 is also provided on the T-bar 10. This lower heat sink 60 is preferably built into a rest shelf 62 of the T-bar 10 which also functions to hold edges of ceiling tiles C (
More specifically, and with continuing reference to
The T-bar 10 could be formed of other materials, with emphasis placed on the ability of the material to facilitate conduction heat transfer therethrough, and also have desirable weight and strength characteristics to operate as a portion of a dropped ceiling system. Other materials which might be suitable in some circumstances include steel. It is also conceivable that the T-bar 10 could be formed of separate components attached together, with the separate components either being made of a common material or from different materials. If the different portions of the T-bar 10 are formed of different materials and different subassemblies, these subassemblies are preferably fixedly held adjacent each other such that the T-bar 10 functions primarily as a single unit.
The cross-section of the T-bar 10 generally includes a spine 12 which is preferably a somewhat thin planar structure which extends substantially vertically up from a rest shelf 62. The spine 12 and rest shelf 62 together form an inverted “T” to generally form the T-bar 10. The spine 12 preferably includes a slot 14 near a midpoint thereof, and potentially at other portions passing through the spine 12. The slot 14 is configured to receive tabs 22 of adjacent T-bars 10 that might be suspended from the slot 14 in the T-bar 10 to complete the dropped ceiling. Suspension holes 16 also preferably pass through the spines 12. These suspension holes 16 can accommodate wires or other suspension lines which extend up to anchor points above the dropped ceiling so that the suspension holes 16 act to support the entire dropped ceiling in a desired position (
The T-bar 10 in this embodiment is approximately two feet long. In other embodiments, the T-bar 10 could be longer (or shorter) but preferably has a contour similar to that disclosed in
With particular reference to
When the end of the T-bar 10 opposite the fixed anchor 20 is positioned so that it cannot be readily moved, it is desirable to utilize an adjustable anchor 30 on at least one end of the T-bar 10. With the adjustable anchor 30, the tab 22 can be removed from one of the terminal ends of the T-bar 10 even when each end of the T-bar 10 is positioned where it cannot be translated linearly axial to an elongate axis of the T-bar 10 due to constraints adjacent ends of the T-bar 10.
In particular, and in this exemplary embodiment, the adjustable anchor 30 preferably has a form similar to the fixed anchor 20, except that the tab 22 is capable of translating horizontally and axially along a long axis of the T-bar 10 (along arrow A of
A wing nut 37 or other fastener is preferably provided which can attach to the threaded shaft 35 and affix the adjustable anchor 30 in any given position relative to the slot 34. Thus, for instance, when the T-bar 10 is to be removed from an adjacent T-bar, the wing nut 37 of the adjustable anchor 30 is loosened. Next, the adjustable anchor 30 is allowed to translate with the slot 34 sliding over the threaded shaft 35 until the tab 22 associated with the adjustable anchor 30 has been moved out of the slot 14 in which it is anchored. The entire T-bar 10 can then be translated in a downward direction. The T-bar 10 can then be replaced with a replacement T-bar of any variety. The adjustable anchor 30 can be modified to connect within other existing ceiling systems. In such other ceiling systems the fixed anchor 20 could also be modified to attach within such systems.
With particular reference to
Conduction heat transfer between a lighting module 70 adjacent a lower end of the T-bar 10 can thus more effectively occur through the T-bar 10, to the upper heat sink 40. Convection heat transfer then effectively moves the heat from the heat sink 40 out to air surrounding the upper heat sink 40, to minimize temperature increase of the lighting module 70 and enhance its operating longevity. Also, with LED lighting, such temperature reduction causes the lighting module 70 to most efficiently convert electric power to light, enhancing the efficiency with which the lighting module 70 operates.
The upper heat sink 40 includes at least one fin, but most preferably includes a series of fins extending laterally from each side of an upper end of the spine 12. In the embodiment shown, six fins 44 extend laterally from each side of the spine 12, between an upper end 42 and a lower end 48. Lateral gaps 46 are provided between the adjacent lateral fins 44. Air within the lateral gaps 46 is heated and then passes out of the lateral gaps 46 by natural convection, being replaced by cooler air which is then heated and travels out by natural convection, with this process continuing so that natural convection heat transfer accelerates removal of heat from the T-bar 10 through the upper heat sink 40.
The upper heat sink 40 also acts as a portion of the T-bar 10 which conveniently facilitates attachment of the power supply 80 associated with the lighting module 70 to be mounted to the T-bar 10 in a convenient and reliable manner, as described in detail below.
With continuing reference to
The light housing 50 is preferably rigid in form and shaped along with the other portions of the T-bar 10 as a single unitary mass of material. This light housing 50 includes a top wall 52 which is preferably planar and extends substantially horizontally and acts as an underside of the rest shelf 62 upon which ceiling tiles C are positioned. Side walls 54 extend down from front and back edges of the top wall 52. These side walls 54 are preferably parallel with each other and substantially mirror images of each other. Tips 56 of the side walls 54 define lowermost portions of this light housing 50, with a light supporting space therebetween.
Track slots 58 are preferably provided in the side walls 54 adjacent the tips 56. These track slots 58 can help to hold and direct into the light housing 50 a lighting module 70, such as that described and shown in
The lighting module 70 can be any of a variety of different kinds of lighting modules, but is most preferably an LED lighting module such as the low intensity lighting module 70′ associated with the T-bar 10′ (
With further reference to
Preferably, portions of the lighting module 70 including the enclosure 72 are formed of aluminum or other relatively high rate of heat transfer materials to optimize heat transfer from the light element 76 and associated electronics to the adjacent light housing 50 and other portions of the T-bar 10. The top wall 52 of the light housing 50 is configured to be directly adjacent upper portions of the enclosure 72 of the lighting module 70. In this way, conduction heat transfer can efficiently occur between the lighting module 70 and the light housing 50 of the T-bar 10.
Most preferably, the T-bar 10 includes a lower heat sink 60 in addition to the upper heat sink 40, but could optionally have only the upper heat sink 40 or only the lower heat sink 60. Additionally, further heat sinks could be attached to or formed with the T-bar 10, such as extending laterally from the spine 12 below the upper heat sink 40. The lower heat sink 60 includes a plurality of fins extending up from the rest shelf 62. These fins preferably include an outer fin 64 most distant from the spine 12 and short fins 66 between the outer fins 64 and the spine 12. Vertical gaps 68 are provided between the fins 64, 66.
While these fins 64, 66 generally act to enhance convection heat transfer, these fins 64, 66 also are preferably configured so that air between the fins 64, 66, and within the gaps 68 is not trapped, but rather can travel out (along arrow H of
With particular reference to
The power supply 80 is preferably generally provided as a module 84 in an enclosure that is mounted upon a plate 82 which is preferably substantially planar and configured to be aligned substantially coplanar with the spine 12. In this way, the power supply 80 and associated mounting hardware generally remain in an area directly above the T-bar 10 so that ceiling tiles C resting upon the T-bar 10 can still be readily moved off of the T-bar 10 to replace ceiling tiles C and to access space above the dropped ceiling.
A separate bracket 86 is preferably provided which is removably and adjustably attachable, such as through a fastener 88 to the plate 82. In one embodiment, this fastener 88 is in the form of a wing nut acting on a threaded shaft mounted to the plate 82. A channel 83 is preferably formed of a plate 82 and a channel 87 is preferably formed on the bracket 86. These channels 83, 87 are preferably complemental in form and facing each other. These channels 83, 87 preferably have a height similar of a height between the upper end 42 and lower end 48 of the upper heat sink 40. Thus, when the fastener 88 tightens the bracket 86 toward the plate 82, the channels 83, 87 can grip the upper heat sink 40 and hold the entire plate 82 and associated module 84 of the power supply 80 rigidly to the T-bar 10.
Wiring (
While the T-bar 10 of this preferred embodiment has been described in an embodiment where a lighting module is held within a light housing 50 of the T-bar 10, the T-bar 10 could support other structures which require heat dissipation, other than lighting, or lighting other than LED lighting. For instance, a fluorescent light bulb could be supported within the light housing 50 according to this invention. Other heat generating accessories desired to be mounted within the ceiling could also be mounted to the T-bar 10, for instance loud speakers could be fitted to lower portions of the T-bar 10 with heat dissipation provided by the various heat sinks 40, 60 of the T-bar 10 according to various different embodiments of this invention.
This disclosure is provided to reveal a preferred embodiment of the invention and a best mode for practicing the invention. Having thus described the invention in this way, it should be apparent that various different modifications can be made to the preferred embodiment without departing from the scope and spirit of this invention disclosure. When structures are identified as a means to perform a function, the identification is intended to include all structures which can perform the function specified. When structures of this invention are identified as being coupled together, such language should be interpreted broadly to include the structures being coupled directly together (or formed together) or coupled together through intervening structures. Such coupling could be permanent or temporary and either in a rigid fashion or in a fashion which allows pivoting, sliding or other relative motion while still providing some form of attachment, unless specifically restricted.
| Number | Name | Date | Kind |
|---|---|---|---|
| 20040213003 | Lauderdale | Oct 2004 | A1 |
| 20060262521 | Piepgras et al. | Nov 2006 | A1 |
| Number | Date | Country | |
|---|---|---|---|
| 20110222270 A1 | Sep 2011 | US |
