T-bar for suspended ceiling with heat dissipation system for LED lighting

Abstract

The T-bar includes an elongate rigid spine extending between terminal ends including either a fixed anchor or adjustable anchor for attachment to adjacent T-bars or other supports. An upper heat sink is provided on an upper portion of the spine to enhance heat transfer from the T-bar to air surrounding upper portions of the T-bar. A light housing is provided on a lower portion of the T-bar which is configured to support a lighting module therein, such as a light emitting diode (LED) light. A lower heat sink is provided above this light housing and integrated into a rest shelf which supports ceiling tiles adjacent the T-bar. A power supply is provided which can be removably attached to the T-bar and provide appropriately conditioned power for the lighting module.

Claims

1. A T-bar for a suspended ceiling, comprising in combination: an elongate substantially rigid plate extending between terminal ends including a first terminal end and a second terminal end; said plate formed at least partially of a material having a higher than average thermal conductivity; said terminal ends each adapted to be coupled to adjacent supports; a lower portion of said plate including a pair of rest shelves extending from opposite lateral sides of said plate, said rest shelves each adapted to support an edge of a ceiling tile resting upon each said rest shelf; at least one light source carried by said lower portion of said plate; a plurality of fins with gaps therebetween forming an upper heat sink, said fins coupled to a portion of said plate above at least one of said rest shelves, said fins in heat transfer connection with said plate and said light source, said fins enhancing a surface area available for heat transfer to air adjacent said plate; wherein said upper heat sink is located at an upper end of said plate opposite said rest shelves; wherein a power supply is provided adapted to deliver electric power to said light source, said power supply adapted to be attached to said upper heat sink; and wherein said power supply is mounted upon a mounting plate, and wherein a bracket is supplied adjacent said mounting plate and adjustably attachable relative to said mounting plate with a channel between said bracket and said mounting plate, said channel having a contour matching a contour of said upper heat sink in the form of said plurality of fins, such that when said bracket is tightened toward said mounting plate, said upper heat sink is gripped between said bracket and said mounting plate within said channel, to cause said power supply to be supported by said upper heat sink.

2. The T-bar of claim 1 wherein said terminal ends each include tabs attachable to slots in plates of adjacent T-bars within a dropped ceiling system.

3. The T-bar of claim 2 wherein at least one of said terminal ends includes an adjustable anchor, said adjustable anchor including a sliding plate having a tab at a tip thereof, said sliding plate adjustably attachable to said plate to adjust a distance between said terminal ends of said T-bar.

4. A T-bar for a suspended ceiling, comprising in combination: an elongate substantially rigid plate extending between terminal ends including a first terminal end and a second terminal end; said plate formed at least partially of a material having a higher than average thermal conductivity; said terminal ends each adapted to be coupled to adjacent supports; a lower portion of said plate including a pair of rest shelves extending from opposite lateral sides of said plate, said rest shelves each adapted to support an edge of a ceiling tile resting upon each said rest shelf; at least one light source carried by said lower portion of said plate; at least one fin coupled to a portion of said plate above at least one of said rest shelves, said fin in heat transfer connection with said plate and said light source, said fin enhancing a surface area available for heat transfer to air adjacent said plate; wherein said at least one fin forms a portion of an upper heat sink coupled to said plate, said upper heat sink including a plurality of fins and a plurality of gaps between said fins; wherein said upper heat sink is located at an upper end of said plate opposite said rest shelves; wherein a power supply is provided adapted to deliver electric power to said light source, said power supply adapted to be attached to said upper heat sink; and wherein said power supply is mounted upon a mounting plate, and wherein a bracket is supplied adjacent said mounting plate and adjustably attachable relative to said mounting plate with a channel between said bracket and said mounting plate, said channel having a contour matching a contour of said upper heat sink in the form of said plurality of fins, such that when said bracket is tightened toward said mounting plate, said upper heat sink is gripped between said bracket and said mounting plate within said channel, to cause said power supply to be supported by said upper heat sink.

5. The T-bar of claim 4 wherein said upper heat sink includes at least one fin coupled to and extending from each opposite lateral side of said plate.

6. The T-bar of claim 5 wherein said upper heat sink includes a plurality of fins coupled to and extending from each opposite lateral side of said plate.

7. The T-bar of claim 4 wherein said rest shelf includes at least one fin thereon.

8. The T-bar of claim 7 wherein said light source includes a light emitting diode, said light emitting diode in heat transfer contact with said rest shelves and said plate.

9. The T-bar of claim 8 wherein a light source housing extends down from said rest shelves to a pair of lower edges, said housing having a light supporting space between said edges; and wherein said housing, said upper heat sink and said plurality of fins are each formed from a unitary mass of material having higher than average thermal conductivity.

10. A method for enhancing the operating life of a dropped ceiling T-bar mounted light emitting diode lighting system, including the steps of: providing at least one light emitting diode light suspended from a lower portion of a T-bar; configuring the T-bar to include a pair of rest shelves each adapted to support ceiling tiles thereon; configuring the T-bar to include a single plate extending up from the pair of rest shelves; forming the T-bar at least partially of a material having a higher than average thermal conductivity; providing a heat sink on the T-bar with at least one fin located above at least one of the rest shelves; connecting the heat sink in heat transfer relationship with the plate and the light emitting diode light such that heat generated by the light is conducted to the heat sink to reduce a temperature of the light and correspondingly enhance the operating life of the light; configuring the plate to include a plurality of heat sink fins extending at least partially horizontally from opposite sides thereof with gaps between the fins; and providing a light source power supply which includes a support bracket and a mounting plate adjustably attachable to each other with a channel formed between the bracket and the mounting plate, the channel of complemental form with the heat sink on the T-bar, such that the light source power supply can be coupled to the T-bar through the bracket, mounting plate and heat sink.

11. The method of claim 10 including the further step of configuring ends of the T-bar to include tabs attachable to slots in plates of adjacent T-bars.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a perspective view of a T-bar according to a preferred embodiment of this invention configured to include lighting mounted to a lower portion thereof and with heat dissipating structures above the light source.

(2) FIG. 2 is a detail of that which is shown in FIG. 1 and with central portions of the T-bar cut away.

(3) FIG. 3 is a full sectional view of the T-bar of FIGS. 1 and 2.

(4) FIG. 4 is a full sectional view similar to that which is shown in FIG. 3 but with included ceiling panels resting upon the T-bar and a lighting module located within a light housing of the T-bar.

(5) FIG. 5 is a perspective view of a dropped ceiling system including the T-bar of this invention and with a portion of a ceiling tile cut away to reveal portions of the T-bar above the dropped ceiling, as well as a power supply coupled to the T-bar and for supplying electric power to the lighting according to this invention.

(6) FIG. 6 is a perspective view of the power supply for supplying power to the light module of this invention, shown attached to the T-bar of FIG. 1, with the T-bar shown in broken lines.

(7) FIG. 7 is a sectional view of that which is shown in FIG. 6 and with the power supply exploded away from the T-bar and shown in phantom coupled to the T-bar to illustrate how the power supply is removably attachable to the T-bar.

(8) FIG. 8 is a perspective view of a T-bar with included lighting module according to an alternative embodiment featuring low intensity light emitting diode (LED) lighting technology.

(9) FIG. 9 is a perspective view of the T-bar of one form of this invention with included lighting module in the form of three high intensity light emitting diodes (LEDs), for example.

DESCRIPTION OF THE PREFERRED EMBODIMENT

(10) 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 (FIG. 1) forming a portion of a dropped ceiling system (FIG. 5) with the T-bar including a lighting module 70 (FIGS. 4, 5, 8 and 9) coupled to a lower end of the T-bar 10 for providing lighting in a space below the dropped ceiling system. The T-bar 10 includes heat dissipating structures including an upper heat sink 40 and lower heat sink 60 in this preferred embodiment for dissipating heat from the lighting module 70 or other heat sources adjacent the T-bar 10.

(11) In essence, and with particular reference to FIGS. 1-3, basic details of the T-bar 10 and associated features of this invention are described, according to this most preferred embodiment. The T-bar 10 is an elongate rigid structure extending between terminal ends and preferably having a substantially constant contour between the two terminal ends of the T-bar 10. A fixed anchor 20 is located at one of the terminal ends of the T-bar 10. An adjustable anchor 30 is provided at the opposite terminal end of the T-bar 10. The adjustable anchor 30 can be adjusted in length slightly (arrow A of FIGS. 1 and 2). The anchors allow the T-bar 10 to be connected to adjacent T-bars or other suspension structures, with the adjustable anchor 30 facilitating the process of attaching and detaching the T-bar 10 to adjacent structures, typically standard conventional prior art T-bars within a conventional dropped ceiling system.

(12) 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 (FIGS. 4 and 5) adjacent the T-bar 10. A power supply 80 is provided (FIGS. 6 and 7) which can be attached to the T-bar 10, such as by removable attachment in a manner gripping the upper heat sink 40. The T-bar 10 thus supports the ceiling tiles C and also is configured to include lighting therein and adapted to transfer heat away from lighting or other structures adjacent lower portions of the T-bar 10 and to also support a power supply 80 for the lighting.

(13) More specifically, and with continuing reference to FIGS. 1-3, particular details of the structure of the T-bar 10 itself are described, according to this most preferred embodiment. The T-bar 10 is preferably a rigid elongate structure formed of aluminum Most preferably, the T-bar 10 is extruded so that it has a constant cross-sectional form (FIG. 3) including the various features provided by the preferred embodiment of this invention.

(14) 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.

(15) 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 (FIG. 5). Additional suspension holes 16 can be provided if required.

(16) 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 FIGS. 1-3 regardless of the length of the T-bar 10. Another standard size for the T-bar 10 would typically be four feet. Conceivably in particularly long lengths, the T-bar 10 might be slightly changed in geometry to have the structural strength required to remain rigid over such long spans. Other modifications to the T-bar 10 can be made consistent with known techniques for T-bar modification within the dropped ceiling T-bar art.

(17) With particular reference to FIG. 2, details of the fixed anchor 20 and adjustable anchor 30 for the terminal ends of the T-bar 10 are described, according to this preferred embodiment. While the T-bar 10 could conceivably include two fixed anchors 20 or two adjustable anchors 30, preferably the T-bar 10 includes one fixed anchor 20 and one adjustable anchor 30. The fixed anchor 20 includes a tab 22 defining a thin axial extension from the spine 12 sized to fit within the slot 14 of another T-bar. A lower portion of this tab 22 is preferably configured with a lower notch 24. A tooth 26 preferably is provided beyond the lower notch 24 and defines a portion of the tab 22 lower than other portions of the tab 22. Taken together, the tab 22 with the lower notch 24 and tooth 26 allow the fixed anchor 20 to pass through a slot 14 or other related support structure with the tooth 26 hanging down beyond the slot 14 and with the lower notch 24 straddling the slot 14, so that the tab 22 is generally held within the slot 14. To remove the fixed anchor 20 from within the slot 14, a user would lift slightly on the T-bar 10 and then translate the tab 22 of the fixed anchor 20 out of the slot 14 by translating the entire T-bar 10.

(18) 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.

(19) 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 FIGS. 1 and 2). The adjustable anchor 30 is preferably mounted on a plate 32. This plate 32 includes a slot 34 therein and resides within a recess 36 at an end of the spine 12, adjacent the terminal end having the adjustable anchor 30 thereon. The recess 36 defines a portion of the spine 12 of only partial thickness within which the plate 32 resides. A threaded shaft 35 passes through the slot 34 and is fixed to the spine 12. This slot 34 can slide relative to the threaded shaft 35 so that the adjustable anchor 30 is allowed to translate linearly in a horizontal direction, but is restrained from other motion.

(20) 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.

(21) With particular reference to FIGS. 2-4, particular details of the upper heat sink 40 of the T-bar 10 are described, according to this most preferred embodiment. The T-bar 10 is preferably configured with the upper heat sink 40 formed and positioned to efficiently transfer heat from the T-bar 10 to air space adjacent upper portions of the T-bar 10. To facilitate such heat transfer, the upper heat sink 40 is provided. By enhancing a surface area of the T-bar 10 adjacent the upper heat sink 40, natural convection is accelerated so that heat is drawn away from the T-bar 10 more rapidly.

(22) 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.

(23) 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.

(24) 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.

(25) With continuing reference to FIGS. 2-4, details of the light housing 50 of this invention are described according to this most preferred embodiment. The light housing 50 defines a portion of the T-bar 10 which is particularly configured to contain a lighting module 70 therein, such as a light emitting diode (LED) lighting module 70. The light housing 50 could have a variety of different configurations with the configurations shown here merely being one such effective configuration.

(26) 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.

(27) 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 FIG. 4, including a light element 76 that is preferably in the form of a light emitting diode (LED).

(28) 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 (FIG. 8) or the high intensity lighting module 70 associated with the T-bar 10 shown in FIG. 9. In the embodiment of FIG. 8, thirty separate LEDs make up the low intensity lighting module 70. In the embodiment of FIG. 9, three high intensity LEDs provide the lighting module 70 and would typically provide a similar amount of light (if not more) than that supplied by the low intensity lighting module of FIG. 8. High intensity LEDs require an even greater amount of heat dissipation than low intensity LEDs for optimal life.

(29) With further reference to FIG. 4, the particular details of the lighting module 70 preferably include an enclosure 72 which fits within the light housing 50 and includes side rails 74 which rest within the track slots 58 of the light housing 50 to support the lighting module 70 within the light housing 50. A light element 76 is included within the lighting module 70 as well as required electronics. A reflector 78 is preferably provided to optimally reflect most of the light down to the space below the lighting module 70.

(30) 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.

(31) 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.

(32) 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 FIG. 4) of these gaps. By providing the outer fins 64 as tall fins, taller than the short fins 66, such a gap is provided for passage of air (along arrow H of FIG. 4) with the ceiling tile C resting upon the outer fin 64 and above the short fins 66. If required, portions of the ceiling tile C adjacent the rest shelf 62 could be adjusted geometrically and/or formed of alternate materials to ensure that this gap for heat transfer along arrow H is maintained.

(33) With particular reference to FIGS. 5-7, details of the power supply 80 for conditioning and delivering power to the lighting module 70 and mounting the power supply 80 to the T-bar 10 are described, according to a most preferred embodiment. The light element 76 within the lighting module 70 typically requires electric power having a particular voltage, current and potentially cycle rate (for AC power) and perhaps other characteristics for optimal performance. The power supply 80 is preferably provided to transform available power into power having a form most optimal for powering the light source 76 within the lighting module 70. In the case of LED lighting, typically low voltage DC power is required. Often available power for the lighting is in the form of between 110 volt and 277 volt AC power. The power supply 80 in such a configuration would be primarily in the form of an AC to DC transformer with an output voltage matching that required for the LED lighting involved.

(34) 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.

(35) 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.

(36) Wiring (FIG. 5) extends from a source of power down to the module 84 of the power supply 80. Additional wiring (not shown) would be routed from the module 84 down to the lighting module 70, such as through holes in the top wall 52 of the light housing 50, to provide power to the lighting module 70. It is conceivable that a single power supply 80 could be provided for each lighting module 70 of each T-bar 10, or a single power supply 80 could serve more than one lighting module 70 of multiple separate T-bars 10.

(37) 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.

(38) 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.