Luminaire heat sink

Abstract

The present application is directed to heat sinks for light emitting devices. In particular, the heat sinks can provide effective heat dissipation in a variety of different orientations and positions. In one exemplary heat sink, different groups (110, 120, 130, 140) of essentially parallel fins (112, 122, 132, 142) can be separated and disposed at particular angles to form fluid channels (114, 124, 134, 144, 108 and 109) that enable fluid flow in different directions and orientations.

Claims

1. A heat sink for a light-emitting device comprising: a first group of fins forming first fluid channels on a surface of the heat sink, wherein said fins of said first group are essentially parallel; and a second group of fins disposed adjacent to said first group of fins and forming second fluid channels on the surface of the heat sink, wherein said fins of said second group are essentially parallel and wherein an average angle between said fins of said first group and said fins of said second group is greater than 15 and less than 165; wherein one or more end points of one or more said fins of said first group are disposed between two or more end points of two or more said fins of said second group within a corresponding channel of said second fluid channels that is defined by the two or more said fins of said second group.

2. The heat sink of claim 1, wherein the end points of said fins of said first group are disposed below the end points of said fins of said second group.

3. The heat sink of claim 2, wherein each of the end points of said fins of said second group are disposed centrally in a corresponding channel of said first fluid channels.

4. The heat sink of claim 1, further comprising: a third group of fins forming third fluid channels on the surface of the heat sink, wherein said fins of said third group are essentially parallel and mirror said fins of said first group; and a fourth group of fins forming fourth fluid channels on the surface of the heat sink, wherein said fins of said fourth group are essentially parallel and mirror said fins of said second group.

5. The heat sink of claim 1, wherein the surface of the heat sink is at least one of sloped or curved at outer edges of said first and second fluid channels.

6. The heat sink of claim 5, wherein the surface of the heat sink is dome-shaped.

7. Alighting system comprising a light-emitting device and the heat sink of claim 1 disposed on a backside of said light-emitting device.

8. The lighting system of claim 7, wherein the first group of fins is disposed over the light-emitting device.

9. The lighting system of claim 8, wherein the second group of fins is disposed over power supply components for the light-emitting device.

10. The lighting system of claim 9, wherein the heat sink further comprises: a third group of fins forming third fluid channels on the surface of the heat sink, wherein said fins of said third group are essentially parallel and mirror said fins of said first group and wherein said third group of fins are disposed over the light-emitting device; and a fourth group of fins forming fourth fluid channels on the surface of the heat sink, wherein said fins of said fourth group are essentially parallel and mirror said fins of said second group and wherein said fourth group of fins are disposed over the power supply components for the light-emitting device.

11. A heat sink for a light-emitting device comprising: a first group of fins extending from a surface of the heat sink and forming first fluid channels on the surface of the heat sink, the first group of fins being essentially parallel to each other; a second group of fins extending from the surface and disposed adjacent to the first group of fins and forming second fluid channels on the surface of the heat sink, the second group of fins being essentially parallel to each other; wherein an average angle between the first group of fins and the second group of fins is greater than 15 and less than 165; and wherein the surface of the heat sink is curved at outer edges of said first and second fluid channels and flat at opposite, interior edges of said first and second fluid channels.

12. The heat sink of claim 11, wherein the first group of fins is disposed over the light-emitting device.

13. The heat sink of claim 11, wherein the second group of fins is disposed over a power supply component for the light-emitting device.

14. The heat sink of claim 13, further comprising: a third group of fins forming third fluid channels on the surface of the heat sink, the third group of fins being essentially parallel to each other and mirroring the first group of fins, wherein the third group of fins is disposed over the light-emitting device; and a fourth group of fins forming fourth fluid channels on the surface of the heat sink, the fourth group of fins being essentially parallel to each other and mirroring the second group of fins, wherein the fourth group of fins is disposed over the power supply component for the light-emitting device.

15. A lighting system comprising a light-emitting device and the heat sink as recited in claim 11 disposed on a backside of the light-emitting device.

16. A heat sink for a light-emitting device comprising: a first group of fins forming first fluid channels on a surface of the heat sink, wherein said fins of said first group are essentially parallel; and a second group of fins disposed adjacent to said first group of fins and forming second fluid channels on the surface of the heat sink, wherein said fins of said second group are essentially parallel and wherein an average angle between said fins of said first group and said fins of said second group is greater than 15 and less than 165; wherein one or more said fins of said first group are at least partially disposed between two or more said fins of said second group within a corresponding channel of said second fluid channels that is defined by the two or more said fins of said second group.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the drawings, like reference characters generally refer to the same parts throughout the different views. Also, the drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention.

(2) FIG. 1 illustrates a side-view of a lighting system including a heat sink according to an exemplary embodiment.

(3) FIG. 2 illustrates a backside view of a lighting system including a heat sink according to an exemplary embodiment.

(4) FIG. 3 illustrates a heat dissipative fluid flow across a heat sink of a lighting system according to an exemplary embodiment when the lighting system is oriented horizontally.

(5) FIG. 4 illustrates a heat dissipative fluid flow across a heat sink of a lighting system according to an exemplary embodiment when the lighting system is oriented vertically.

(6) FIG. 5 illustrates a fin configuration that forms a separation channel between groups of fins according to an exemplary embodiment.

(7) FIG. 6 illustrates a fin configuration that forms a winding channel between groups of fins according to an exemplary embodiment.

DETAILED DESCRIPTION

(8) As noted above, a problem with typical heat sink designs for lighting devices is that they operate effectively only in particular orientations. For example, when oriented in certain positions, these heat sink fixtures can trap fluid and prevent it from dissipating heat effectively. In addition, water and debris, including dust and dirt, can also create blockages of heat dissipating fluids when the fixture is in these orientations.

(9) More generally, Applicants have recognized and appreciated that it would be beneficial to angle fins in a way that forms fluid channels that can effectively dissipate heat in a variety of orientations of the heat sink fixture. In particular, exemplary configurations can provide a relatively unobstructed fluid flow in a plurality of directions. Further, groups of fins can be separated to enable fluid to flow through the fins in the separated areas in directions that are different from directions of channels formed within the groups of fins. Further, the heat sink can include sloped and/or curved surfaces to drain water and implement roll-off of debris.

(10) Referring to FIGS. 1-2, one exemplary embodiment 100 of a lighting system includes groups of fins that form fluid channels on the surface of a heat sink 105 through which fluid, for example air, water, and/or other suitable fluid, can flow to effect heat dissipation for a light-emitting device 102. The fins can be formed in a specific pattern along the back of the system fixture. In other words, the heat sink 105 can be disposed on a backside of the light-emitting device 102, opposite to the light-emitting surface of the device 102. The fin features can be cast or molded into the luminaire housing. The light-emitting device 102 can be an LED or any other suitable light source. The particular embodiment illustrated in FIGS. 1-2 includes a mount 106 and four groups of fins 110, 120, 130 and 140. However, any other suitable number of groups of fins can be employed, including two groups, three groups, four groups, eight groups, etc. As illustrated in FIGS. 1-2, the group 110 includes fins 112 that form fluid channels 114, the group 120 includes fins 122 that form fluid channels 124, the group 130 includes fins 132 that form fluid channels 134 and the group 140 includes fins 142 that form fluid channels 144. In this particular example, group 120 is adjacent group 110, while group 140 is adjacent group 130. In addition, group 130 is disposed laterally from group 110 and mirrors group 110, while group 140 is disposed laterally from group 120 and mirrors group 120. As illustrated in FIG. 2, the channel 108 along the x-axis and the channel 109 along y-axis allow for air or other fluid to escape unobstructed. For example, as illustrated in FIG. 3, when the system 100 is arranged horizontally, the heat can dissipate along directions 302 and 304. In turn, as illustrated in FIG. 4, when the system 100 is arranged vertically, the heat can dissipate along directions 402 and 404. The channels 108 and 109 also allow for water drainage from rain and snow, and roll-off of outdoor debris, such as dust and dirt, through the channels 108 and 109. The rear surface 107 is domed in this particular embodiment and aids in drainage from fixture back as well as in thermal dissipation. As illustrated in FIG. 1, the surface 104 of the heat sink 105 at least near its outer edges, preferably along the whole surface 107, is curved or sloped to permit the drainage of water and roll-off of debris.

(11) The fins are located on the face opposite the direction of light output. The fin pattern should have at least two groups of fins. As illustrated in FIGS. 1-2, within each group 110, 120, 130 and 140 the fins are generally parallel to each other with an overall average angle established for each group. Here, the fins of any particular group, such as fins 112 of group 110, are essentially parallel in that their angle can vary from the average angle of its corresponding group, such as group 110, by about 15 or less. Preferably, the angles of the fins of a given group vary by about 5 or less from the corresponding average angle of the group and most preferably the angles of the fins of a given group vary by about 1 or less from the corresponding average angle of the group. However, in any case, the fins within a given group could be configured so that any given fin should not impede airflow between any of the other fins. In one example, the average angle of the first group is preferably about 15-165 degrees apart from the average angle of the second group. For example, the average angle between the fins of group 110 and the fins of group 120 is 15 and 165. Similarly, in this example, the average angle between the fins of group 130 and the fins of group 140 is 15 and 165. As illustrated in FIG. 2, this angle relationship forms a V shape with the two groups of fins 110 and 120 and similarly with the two groups of fins 130 and 140. With the point of the V pointing in a direction perpendicular to the direction of fluid flow (i.e., fluid flows in a general direction along the y-axis in FIG. 2), fluid can flow up one group of fins, e.g., group 120, and out of the other group of fins, e.g., group 110, without having to make a relatively sharp turn. Preferably, the angle between the two groups of fins, for example, the angle between groups 110 and 120 and/or the angle between groups 130 and 140, is about 90. This balances performance between x and y directions. However, the angle can be adjusted to bias the performance in a particular axis. For example, if it were desirable to have a slightly better performance in the y-axis direction in FIG. 2, the angle between groups 110 and 120 and/or the angle between groups 130 and 140 can be obtuse to reduce vertical resistance. Similarly, if it were desirable to have a slightly better performance in the x-axis direction, the angle between groups 110 and 120 and/or the angle between groups 130 and 140 can be acute. It should be noted that, according to exemplary aspects, the median angle between any two groups of fins need not align with the x- or y-axis shown FIG. 2. Rather, the median angle between any two groups of fins can be aligned with any arbitrary axis.

(12) To enable the fin pattern to effectively dissipate heat in an orientation where the direction to which the V points is in line with the direction of fluid flow (i.e., fluid flows in the general direction along the x-axis in FIG. 2), the point of the V could be broken and the groups of fins could be separated. This will prevent the fluid from being trapped in the V shape. This can be achieved by in a variety of different embodiments.

(13) For example, as illustrated in FIG. 5, a first group 1010 of fins 1012 is disposed adjacent to a second group 1020 of fins 1022. The end points 1014 of the first group 1010 of fins 1012, which can be group 110, that are nearest to the second group 1020 of fins 1022, which can be group 120, are separated from end points of 1024 of the second group that are nearest to the first group. End points 1014 are nearest to group 1020 in the sense that they are nearer to the group 1020 than endpoints 1016 of the fins 1012. Similarly, end points 1024 are nearer to the group 1020 than endpoints 1026 of the fins 1022. As illustrated in FIG. 5, a cutaway channel 1015, of which channel 108 is an implementation, is created to break the tip of the V and allow fluid to flow in and out of this area. Here, the end points 1014 of the fins of the group 1010 are disposed above the end points 1024 of the fins of the group 1020. In particular, the end points 1014 of fins of the group 1010 are disposed directly above a corresponding end point 1024 of the fins of the group 1020. In this way, the groups of fins can form a direct, unobstructed channel 1015 across at least a portion of the surface of the heat sink to permit a relatively large amount of fluid to flow across the heat sink, which can improve the heat dissipative function of the heat sink, as noted above. Further, disposing the endpoints of the first group directly above the corresponding end points of the fins of the second group enables fluid to flow seamlessly from channels 1018 of one group of the fins to channels 1028 of the other group of the fins, while at the same time providing the channel 1015.

(14) Alternatively, the fins of the two groups can be alternating and can partially overlap each other. This configuration permits the fluid to take a winding or zig-zag path through the length of the fixture along this direction. For example, as illustrated in FIG. 6, a first group 1110 of fins 1112 is disposed adjacent to a second group 1120 of fins 1122. The end points 1114 of the first group 1110 of fins 1112, which can be group 110, that are nearest to the second group 1120 of fins 1122, which can be group 120, are separated from end points 1124 of the second group that are nearest to the first group. Specifically, the end points 1114 of fins of the first group 1110 are disposed below the end points 1124 of the fins of the second group 1120. This feature can enable fluid to flow around the fins 1112, 1124 in a winding or zig-zag path around the fins in a general direction that is transverse or otherwise different from the directions of the fluid channels 1118, 1128 formed by the parallel fins. As discussed above, this winding or zig-zag path permits the fluid to flow over a larger surface area of the heat sink and can improve the heat dissipation qualities of the heat sink. In the particular example illustrated in FIG. 6, each of the end points 1114 of the fins of the first group are disposed centrally in a corresponding channel 1128 of the fins of the second group 1120. Similarly, each of the end points 1124 of fins of the second group 1020 is disposed centrally in a corresponding channel 1118 of the first group of fins. Configuring the fins in this way enables the fluid to flow steadily and consistently around the fins in a generally horizontal direction to provide a more uniform heat dissipation.

(15) It should be noted that the proportions of the groups of fins can be varied. For example, as illustrated in FIG. 2, the fins 112 and 132 of groups 110 and 130 are longer than the fins 122 and 142 of groups 120 and 140. Here, the groups 110 and 130 can be disposed over the light-emitting device 180, such as, for example, an LED, of the fixture system. In turn, the groups 110 and 130 can be disposed over the power supply components 190 for the light-emitting device of the fixture. In this example, the air channel break 108 dividing these groups is located essentially between the light-emitting device portion 180 and the power supply portion 190 of the fixture.

(16) As depicted in FIG. 2, groups 110 and 120 are mirrored by groups 130 and 140 across the fixture to create a general X shape with four groups of fins. Here, the configurations illustrated in FIG. 5 for groups 110 and 120 are mirrored in groups 130 and 140 to break any other V shapes formed by groups 130 and 140. Alternatively, as noted above, the configuration illustrated in FIG. 6 can be employed. It should be noted that, when the pattern is X shaped, there can be two acute and two obtuse angles formed between the groups, or all four groups could be at right angles with respect to each other. Alternatively, there could be three obtuse angles and one acute angle between the groups or there could be three acute angles and one obtuse angle between the groups.

(17) As indicated above, the surface created at the base of the fins, in between the fins, is sloped, curved or domed to prevent water and debris from collecting in the fluid channels of the heat sink. In particular, at least the outer edges 104 of the surface of the heat sink 105 can be curved or sloped. In the dome implementation, the highest point of the back surface 107 can be located at the central location where all the V shapes point, i.e. at the intersection between the x- and y-axes in FIG. 2. The back surface 107 can be sloped, curved or domed away from this point towards the perimeter of the light fixture.

(18) The lighting system 100 can be made from the following non-limiting examples of materials: die-cast aluminum (A360, A380), sand-cast aluminum, machined aluminum (6061-T6), thermally conductive plastics and/or die-cast magnesium. The dimensions of a preferred embodiment of the system 100 are approximately 340 mm165 mm. In addition, in this exemplary embodiment, the fins can be approximately 2-3 mm thick at the thinnest section and can be about 4-6 mm thick at the bases. The fluid channels can be approximately 12 mm wide. These dimensions are scalable across any heat sink size.

(19) It should be noted that the fin material can be any type of thermally conductive material. In addition, the specific dimensions described above are only a non-limiting example described for illustrative purposes. Alternative designs can include different angles for the fin pattern, alternative thicknesses in fin size, different perimeter ratios, as well as heights of the fins. Furthermore, the fins could be cast, machined, or molded into the heat sink or attached as a secondary component. Moreover, as discussed above, a benefit of the exemplary embodiments described herein is that they can be employed in a plurality of different operable orientations in a variety of different applications. They can be used for any type of thermal dissipation solution, including, for example outdoor LED luminaire fixtures, such as floods, washes, direct viewing, and grazing fixtures and indoor LED luminaire fixtures, such as floods, washes, direct viewing, grazing, and cove fixtures.

(20) While several inventive embodiments have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and/or structures for performing the function and/or obtaining the results and/or one or more of the advantages described herein, and each of such variations and/or modifications is deemed to be within the scope of the inventive embodiments described herein. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the inventive teachings is/are used. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific inventive embodiments described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, inventive embodiments may be practiced otherwise than as specifically described and claimed. Inventive embodiments of the present disclosure are directed to each individual feature, system, article, material, kit, and/or method described herein. In addition, any combination of two or more such features, systems, articles, materials, kits, and/or methods, if such features, systems, articles, materials, kits, and/or methods are not mutually inconsistent, is included within the inventive scope of the present disclosure.

(21) All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and/or ordinary meanings of the defined terms.

(22) The indefinite articles a and an, as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean at least one.

(23) The phrase and/or, as used herein in the specification and in the claims, should be understood to mean either or both of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Multiple elements listed with and/or should be construed in the same fashion, i.e., one or more of the elements so conjoined. Other elements may optionally be present other than the elements specifically identified by the and/or clause, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, a reference to A and/or B, when used in conjunction with open-ended language such as comprising can refer, in one embodiment, to A only (optionally including elements other than B); in another embodiment, to B only (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc.

(24) As used herein in the specification and in the claims, or should be understood to have the same meaning as and/or as defined above. For example, when separating items in a list, or or and/or shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as only one of or exactly one of, or, when used in the claims, consisting of, will refer to the inclusion of exactly one element of a number or list of elements. In general, the term or as used herein shall only be interpreted as indicating exclusive alternatives (i.e. one or the other but not both) when preceded by terms of exclusivity, such as either, one of, only one of, or exactly one of. Consisting essentially of, when used in the claims, shall have its ordinary meaning as used in the field of patent law.

(25) As used herein in the specification and in the claims, the phrase at least one, in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase at least one refers, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, at least one of A and B (or, equivalently, at least one of A or B, or, equivalently at least one of A and/or B) can refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other elements); etc.

(26) It should also be understood that, unless clearly indicated to the contrary, in any methods claimed herein that include more than one step or act, the order of the steps or acts of the method is not necessarily limited to the order in which the steps or acts of the method are recited.

(27) In the claims, as well as in the specification above, all transitional phrases such as comprising, including, carrying, having, containing, involving, holding, composed of, and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases consisting of and consisting essentially of shall be closed or semi-closed transitional phrases, respectively, as set forth in the United States Patent Office Manual of Patent Examining Procedures, Section 2111.03.