Patent Publication Number: US-11022281-B2

Title: Lighting system

Description:
CLAIM OF PRIORITY UNDER 35 U.S.C. § 119 
     This patent application is a continuation and claims benefit and priority to Non-Provisional application Ser. No. 16/406,425 filed May 8, 2019, which claims priority to Non-Provisional application Ser. No. 15/991,715 filed May 29, 2018, which claims priority to Non-Provisional application Ser. No. 15/146,516 filed May 4, 2016, which claims priority to Provisional Application No. 62/156,354 entitled “Flexible Surface-Mounted Light Source” filed May 4, 2015, and assigned to the Assignee hereof, the entire contents of which are hereby expressly incorporated by reference herein. 
    
    
     BACKGROUND 
     Field 
     The present invention relates generally to lighting systems, and more specifically to lighting fixtures. 
     Background 
     Installation and maintenance of lighting units, and in particular LED lighting units, may be time-consuming, require specialized tools, or otherwise present difficulties and challenges. For example, those skilled in the art will recognize that light fixtures generally are heavy, and require an installer to disassemble and/or assemble as many as five different components during installation. Moreover, currently-available light fixtures require that the installer hold the heavy fixture while coupling power sources; in commercial applications requiring the installation of hundreds of fixtures, easing the burden on the installers and speeding the rate of installation can save thousands of dollars. 
     Currently-available light fixtures are also prone to excessive heat generation, which may result in a degradation of performance of electronics carried therein. 
     Currently-available light fixtures are also prone to premature damage or breaking, particularly in rough environments such as dorms or manufacturing buildings. 
     A need therefore exists for a lighting unit that is easier and simpler to install and maintain, less prone to performance degradation, and/or can withstand impacts or rough handling. 
     SUMMARY 
     In one example, a lighting system is provided. The exemplary lighting system has a mounting fixture and a light fixture. The mounting fixture is configured to engage a mounting surface. The light fixture is configured to engage the mounting fixture and has a driver configured to drive a light source. A first fastener having a movable elongated member is configured to removably couple the light fixture to the mounting fixture in an extended configuration. A second fastener having a quick connect feature is configured to removably couple the light fixture to the mounting fixture in a retracted configuration. 
     In another example, a method of installing a lighting system is provided. The exemplary the method includes providing a mounting fixture, a light fixture, a first fastener, and a second fastener. Providing includes providing a mounting fixture configured to engage a mounting surface. Providing further includes providing a light fixture configured to engage the mounting fixture and comprising a driver configured to drive a light source. Providing further includes providing a first fastener comprising a movable elongated member. Providing further includes providing a second fastener comprising a quick connect feature. The exemplary method further includes using the first fastener to removably couple the light fixture to the mounting fixture in an extended configuration. The method further includes using the second fastener to removably couple the light fixture to the mounting fixture in a retracted configuration. 
     In another example, a light fixture for a lighting system is provided. The exemplary light fixture includes a driver configured to drive a light source, a first fastener, and a second fastener. The first fastener includes a movable elongated member and is configured to removably couple the light fixture to a mounting fixture in an extended configuration. The second fastener includes a quick connect feature and is configured to removably couple the light fixture to the mounting fixture in a retracted configuration. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a light fixture in an expanded configuration; 
         FIG. 2  is a perspective view of the light fixture in  FIG. 1  in a contracted configuration; 
         FIG. 3  is a perspective view of some components of the light fixture in  FIG. 1 ; 
         FIG. 4  is an end section view of some components of the light fixture in  FIG. 1 ; 
         FIG. 5  is a perspective view of a recess to which a light fixture may be attached; 
         FIG. 6  is a perspective view of a mounting bracket and conduit, without wires; 
         FIG. 7  is a perspective view of a light fixture in an expanded configuration; 
         FIG. 8  is a perspective view of some components of the light fixture in  FIG. 7 ; 
         FIG. 9  is a perspective view of some components of the light fixture in  FIG. 7 ; 
         FIG. 10  is a perspective view of some components of the light fixture in  FIG. 7 ; 
         FIG. 11  is a detailed view of some components of the light fixture in  FIG. 7 ; 
         FIG. 12  is a perspective view of some components of the light fixture in  FIG. 7 ; and 
         FIG. 13  is a flowchart of a method. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments of the present invention include a lighting system that is easily mounted on a building wall or ceiling surface, regardless of the type of electrical connections that are present, is easily installed by service personnel, and is easily and conveniently disassembled for service in the field. The lighting system may also be configurable to produce linear light sources of arbitrary lengths, in some embodiments because of its modular construction. 
     In various embodiments, one or more support cables (two cables in some embodiments) connect a mounting plate or fixture to a light fixture which may carry a light source. The support cables allow the light fixture to hang suspended from the mounting plate at a distance sufficient to permit maintenance on the components of the light source; the distance may be, for example, 10, 20, or 30 cm (though any distance is contemplated herein). 
     One or more pins may connect the mounting plate to the light source when the light source is in its normal, non-suspended state. In some embodiments, four pins (and corresponding holes in the light source and mounting plate) are used. The holes are aligned such that a hole in the light source aligns with a hold in the mounting plate, and each pins passes through both corresponding holes to affix the two objects to each other. A force may be required to remove the pins from the holes; this force may be a result of friction between the pins and the surface of the holes, a result of features in the profile of the pins mating with corresponding features in the surface of the holes, or by any other means. The force may be great enough so that the pins do not unintentionally fall out of the holes but weak enough to permit removal with only finger strength. In some embodiments, the profile of the pin is such that a lip or similar protrusion prevents the pin from being fully withdrawn from one of the holes (in either the mounting plate or the light source, whichever is on the exterior face of the combined unit so that the pin may be withdrawn from the other of the mounting plate or light source). In some embodiments, bolts or screws may be used in lieu of the pins. 
     In some embodiments, an installer of the mounting plate and light source first affixes the mounting plate to a surface, such as a ceiling, with screws, bolts, nails, glue, or similar fasteners. The installer then attaches the support cables, and then the pins. 
     Turning now to  FIGS. 1-3 , a lighting system  100  according to some embodiments is now described. The lighting system  100  may have a mounting fixture  102 , and a light fixture  104  configured to be coupled to the mounting fixture  102  in an extended position by way of one or more first fasteners  106 . The one or more first fasteners  106  may couple the light fixture  104  to the mounting fixture  102  such that the light fixture  104  hangs from the mounting fixture  102 , and is movable and/or removable from the mounting fixture  102 . Those skilled in the art will recognize that the system  100  illustrated in  FIGS. 1-3 , as illustrated, if configured for attachment to an overhead feature such as a ceiling. However, a system  100  configured for attachment to a vertical surface such as a wall is also contemplated herein. For example, the one or more first fasteners  106  or light fixture  104  may, in some embodiments, be configured to hang adjacent to or from a first side  166  of the mounting fixture  102  while a second side  168  of the mounting fixture  102  may be configured for engagement with a mounting surface, such as a wall. In some embodiments, the light fixture  104  or first fastener(s)  106  are configured to hang from or be adjacent a side  170  that opposes the second side  168 , which may be configured for engagement with a mounting surface that is a ceiling or other substantially horizontal surface. In some embodiments, the light fixture  104  or first fastener(s)  106  may be adaptable, and configured to hang from or be positioned in either orientation, that is, relative to the sides  166 ,  170  in the extended configuration. 
     The first fastener(s)  106  may have a movable elongated member. For example, the first fastener(s)  106  may be attached to a first end cap  114  and/or a second end cap  116  in a permanent or semi-permanent manner. For example, one or more third fastener(s)  118  may couple the first fastener(s)  106  to the end cap(s)  114 ,  116 , as most clearly illustrated in  FIG. 1 . The first fastener(s)  106  may be one or more flexible members that bend, contract, or fold as the installer moves the light fixture  104  towards the mounting fixture  102 . The first fastener(s)  106  may be one or more wires or cables that are positioned in an interior space  120  defined between the mounting fixture  102  and the light fixture  104  (see e.g.  FIG. 12  for a better understanding of the space  120 ). 
     Those skilled in the art will generally understand that, although the first fastener(s)  106  are depicted as a flexible cable, the first fastener(s)  106  may include any number of means for removably and/or movably attaching the light fixture  104  to the mounting fixture  102 , including, but not limited to, a cable, chain, a spring, a push-pull linkage. 
     In some embodiments, and as illustrated in  FIG. 3 , a hook and eye engagement  138  is provided for coupling the light fixture  104  to the mounting fixture  102  in the extended position (see  FIG. 1 ). 
     Continuing with  FIGS. 1-2 , one or more second fasteners  112  may be provided for coupling the light fixture  104  to the mounting fixture  102  in a retracted position. In some embodiments, the one or more second fastener(s)  112  may be threaded and configured to engage one or more recesses  140  in the mounting fixture  102  and/or the light fixture  104 . In some embodiments, the second fastener(s)  112  may include interference fit features between the mounting fixture  102  and the light fixture  104 . In some embodiments, the second fastener(s)  112  may have a quick connect feature. In some embodiments, a detent  112  and recess  140  may be provided for coupling the light fixture  104  to the mounting fixture  102  in the retracted configuration. The detent  112  may be spring-biased. In some embodiments, the quick connect feature includes pins  112  that can be pried open using a flathead screwdriver or other similar tool. In some embodiments, a detent in the mounting fixture  104  is configured to engage a passage in the light fixture (not illustrated), such that the light fixture  104  may be fastened to the mounting fixture by simply sliding the light fixture  104  onto the mounting fixture  102 . To disassemble, the detent on the mounting fixture  102  may be depressed using a tool, and the light fixture  104  may be slid off the mounting fixture  102 . In some embodiments, the detent is a one-way detent; that is, the detent may have an angled surface on a lower portion and a flat surface on an upper portion so that the light fixture  104  does not fall off the mounting fixture  102  after installation. 
     In some embodiments, the second fastener(s)  112  may include a hook and eye connection. In some embodiments, end caps  114 ,  116  may provide a disguising effect, and may be coupled to the rest of the light fixture  104  before or after connecting the light fixture  104  in the retracted configuration. 
     As previously mentioned, the mounting fixture  102  may be configured for attachment to a mounting surface, such as, for example, a ceiling, wall, floor, stair, or any other surface, and may be coupled to or configured to be coupled to one or more power source conduits  212 ,  214  (see e.g.  FIG. 6 ) on, behind, or extending through the mounting surface. The mounting fixture  102  may be removably or permanently attached to the mounting surface with screws, bolts, nails, glue, and/or any other fasteners now known or as yet to be developed. The mounting surface itself may be substantially vertical, horizontal, angled, and/or curved, and may be made of any materials suitable for receiving a lighting system  100 , including natural features such as outdoor rocks or walls, or indoor features such as walls or ceilings. Moreover, although the system  100  illustrated is configured for engagement with a mounting surface that is substantially planar, in some embodiments, the system  100  may be configured for engagement with a curved mounting surface, such as, for example, a curved wall, in an aesthetically pleasing manner. 
     In some embodiments, the mounting fixture  102  has multiple power line conduit entry points  184  entry points for power lines and conduits  212 ,  214  carrying power lines (see e.g.  FIGS. 1 and 6 ). In some embodiments, some or all of the entry points  184  are always open. In some embodiments, some or all of the entry points  184  include a punch-out wall  186  to provide an aesthetically pleasing surface  166  if not all entry points  184  are in use. 
     Continuing with  FIGS. 1-2 , and as previously mentioned herein, the light fixture  104  may be coupled to the mounting fixture  102  in an extended configuration by way of one or more first fasteners  106 , and in a retracted configuration by way of one or more second fasteners  112 . Specifically, in some examples, an installer may couple the mounting fixture  102  to the mounting surface, such as a junction box  300  illustrated in  FIG. 4 . After mounting the mounting fixture  102 , the installer may hang the light fixture  104  onto the mounting fixture  102  by way of the first fastener(s)  106 , at which time the installer may couple, fasten, or fix any necessary power, such as the wiring  121  illustrated in  FIG. 1 . 
     In some embodiments, the light fixture  104  is movable or installable as a unit. That is, the light fixture  104  may (a) include or be configured to carry and/or drive a light source  122  such as an LED light source  122 ,  222  (see e.g.  FIGS. 3, 11 ), (b) include wiring  121  for coupling to the mounting fixture  102 , include a battery regulator  124 , a battery backup  126 , a driver  128 , and a processing device  130 . In some embodiments, the light fixture  104  has a first heatsink  132  and a second heatsink  134 . In some embodiments, the light fixture  104  has a light diffuser  136 . The heatsinks  132 ,  134  and the diffuser  136  are discussed in further detail in subsequent section of this document. 
     Continuing with  FIGS. 1-3 , in some embodiments, an installer may attach the mounting fixture  102  to a mounting surface, such as the junction box  300  ( FIG. 4 ) while the light fixture  104  is left sitting on another surface (e.g. on a floor). After the installer has attached the mounting fixture  102 , the installer may lift the light fixture  104  and hang the light fixture  104  onto the mounting fixture  102  in an extended configuration by way of one or more first fasteners  106 . That is, the first fastener(s)  106  maintain the light fixture  104  in a position distant from, but supported by, the mounting fixture  102 , to allow the installer access for coupling wires, power lines, and/or other connections without having to manually support the light fixture  104  during coupling of the wires, etc. When ready, the installer may then bring the light fixture  104  into a retracted position (see e.g.  FIG. 2 ), and couple the light fixture  104  to the mounting fixture  104  by way of one or more second fasteners  112 . 
     Turning now to  FIG. 4 , a relationship between the first heatsink  132  and the second heatsink  134  is now described in further detail. In some embodiments, the first heatsink  132  and the second heatsink  134  may be coupled together to define an interior space  180  therebetween, and at least one of the first heatsink  132  or  134  having an exterior surface  142  exposed to a space exterior of the light source. That is, the first and second heatsinks  132 ,  134  may be configured to conduct thermal energy from multiple interior compartments  180 ,  182 ,  120  of the light fixture  104  to the exterior space. 
     In some embodiments, the exterior surface  142  includes a plurality of fins (not illustrated) so as to improve heat transfer to the exterior space. In some embodiments, the exterior surface  142  has a substantially flat surface. In some embodiments, the exterior surface  142  has an aesthetically pleasing design. In some embodiments, the exterior surface  142  has a plurality of ridges and valleys that increase the surface area exposed to air outside the light fixture  104 . Those skilled in the art will recognize that either of the heatsinks  132 ,  134  may provide the exterior surface  142 . 
     Additionally, or in the alternative, the first and second heatsinks  132 ,  134  may be configured to conduct thermal energy from multiple heat-generating components in different compartments  180 ,  182 ,  120  of the lighting system  100 . For example, the light source  122  may be positioned between the first heatsink  132  and the diffuser  136 . Relatedly, the driver  128  and processing device  130  may be positioned between the first and second heatsinks  132 ,  134 , so that the heatsinks  132 ,  134  both provide thermally conductive paths from the components  128 ,  130  to the exterior surface  142 . The battery regulator  124  and backup  126  may be positioned between the second heatsink  134  and the mounting fixture  102 . 
     In some embodiments, heat-sensitive components  128 ,  130 , that is, those components that are most prone to performance degradation by exposure to heat, may be positioned in the coolest compartment  180  of the light fixture  104 . The coolest compartment  180  may be that space positioned between the first and second heatsink  132 ,  134 . As of the time of this writing, the heat-sensitive components  128 ,  130  may be the processing device  130  and/or the driver  128 ; however, those skilled in the art will recognize that technological advances may change this presumption, and that other heat-sensitive components  128 ,  132  may be or become more suitable for positioning between the first and second heatsinks  132 ,  134 . 
     In some embodiments, the space  182  defined by the first heatsink  132  and the diffuser  136  may reach the highest temperatures. Therefore, the first heatsink  132  may have a plate portion  152  that provides a thermal barrier between the coolest compartment  130  and the hottest compartment  182 . The plate portion  152  may have a thickness that is defined by the anticipated temperature difference between the two compartments  180 ,  182  so as to ensure that heat from the light source  122  does not pass through to the heat-sensitive components  128 ,  130 . In some embodiments, the heat-sensitive components  128 ,  130  are coupled to the second heatsink  134  to provide a direct thermally conductive path from the heat-sensitive components  128 ,  130 , through the second heatsink  134  and to the exterior surface  142  (and first heatsink  132 ). Those skilled in the art will recognize that the thermally conductive paths defined by the first and second heatsinks  132 ,  134  are more thermally conductive than is the air in the compartments  180 ,  182 ,  120 . In some embodiments plate portions in both of the heatsinks  132 ,  134  may be provided, each of the plate portions having a thickness defined by the anticipated temperature difference between first and second compartments  180 ,  182  and/or between second and third compartments  180 ,  120 . In some embodiments, a thickness of the plate in the first heatsink  132  is different from a thickness of the plate in the second heatsink  134 . 
     In some embodiments, the first heatsink  132  is an elongated thermally conductive material positioned adjacent to, above, or on a first side of a light source  122 . That is, a light source  122  may be positioned between the first heatsink  132  and the diffuser  136 . The first heatsink  132  may have an exterior surface  142  exposed to a space exterior of the light source  104  and an interior surface  144  exposed to an interior space defined by the first heatsink  132  and the second heatsink  134 . 
     In some embodiments, at least a portion of the first heatsink  132  is positioned between a light source  122  or light source receptacle  246  (see e.g. receptacle  246  in  FIG. 12 ) and a first side  148  of the driver  128  (see e.g.  FIG. 3 ). In some embodiments, at least a portion of the second heatsink  134  is positioned adjacent a second side  150  of the driver  128 . 
     In some embodiments, the first heatsink  132  and the second heatsink  134  are coupled together to define a thermally conductive path from the light source  122  or light source receptacle  246  and the driver  128  to a space exterior of the light fixture  104 . 
     In some embodiments, the first heatsink  132  has a plate portion  152  exposed to the space defined by the first and second heatsinks  132 ,  134  and/or a space defined by the first heatsink  132  and the diffuser  136 . 
     The plate portion  152  may be coupled to a first flange portion  154 . The first flange portion  154  may be slidingly engaged with a flange  156  in the mounting fixture  102 . In some embodiments, the first heatsink  132  includes a second flange portion  158  slidingly engaged with a flange  160  in the diffuser  136 . Providing a sliding engagement between the first heatsink  132  and the light diffuser  136  introduces a level of robustness not found in currently-available systems that require snap-fitting the diffuser to the mounting features. This level of robustness reduces the chances of the diffuser  136  and light source  122  being broken when exposed to rough environments. 
     Continuing with  FIG. 4 , the first heatsink  132  may include fastening features  162  for coupling one or more end caps  114 ,  116  to the first heatsink  132 , although those skilled in the art will understand that the end caps  114 ,  116  may be fastened to the light fixture  104  using any suitable means. 
     In some embodiments, additional thermal isolation means may be provided to insure that the heat-sensitive components  128 ,  130  are protected, although the inventors have found that the sliding engagement between the heatsinks  132 ,  134  provides sufficient thermal isolation for their purposes for the level of heat generated by currently-available LED light sources  122 . The additional thermal isolation means may include insulating tape, insulating paste, insulating gel, insulating plastic, ceramic, and/or polymer extrusions that fit in the compartment  180  between the two heatsinks  132 ,  134 , or any other thermal isolation means now known or as-yet to be developed. 
     In some embodiments, those components subject to more frequent maintenance are positioned on the second heatsink  134  such that those components are more easily accessible. For example, the battery  126  may be made accessible to a user by moving the light fixture  104  into the expanded configuration. Conversely, the driver  128  and processing device  130  are not subject to routine maintenance, and may be placed between the two heatsinks  132 ,  134  so as to discourage a user from interfering with those components. Similarly, one or both of the end caps  114 ,  116  and diffuser  136  may be removable to expose the light source  122  for maintenance or replacement. 
     In some embodiments, the light fixture  104  includes a motion sensor  164 , as illustrated in  FIG. 2 . The motion sensor  164  may provide signals to the processing device  130  that are indicative of whether or not a person is in proximity of the light fixture  104 . The processing device  130  may be responsive to the motion sensor  164  and configured to adjust a level of light emitted by a light source  122  coupled to the light fixture  104  between a first non-zero level of light and a second non-zero level of light. That is, the light source  104  may be configured to dim without shutting off when a motion sensor  164  provides signals consistent with a room or space being empty. 
     In some embodiments, the driver  128  and/or processing device  130  are configured substantially as described in commonly-owned U.S. Pat. Nos. 9,326,346 and/or 8,358,085, and/or U.S. Patent Publication No. 2011/0121760. The entire contents of these patents and publication are hereby incorporated by reference in their entirety as if fully set forth herein and for all proper purposes. In some embodiments, the lighting system  100  has a thermal control circuit (note illustrated) configured to increase a lifetime of a light source  122  coupled to the light fixture  104 . The thermal control circuit may include circuitry for determining a current thermal operating point of the light source  122  coupled to the light fixture  104 . The thermal control circuit may also include circuitry for obtaining a thermal operating range of the light source  122 , a generator for generating a control signal that adjusts power delivered to the light source  122  based at least in part on the current thermal operating point and the thermal operating range. The thermal control circuit may be coupled to or reside in the processing device  130 . 
     In some embodiments, an interchangeable light diffuser  136  may be provided. For example, the diffuser  136  may be removable upon removal of the caps  114 ,  116  to allow an installer to adjust a level of diffusion and/or to control diffusion to different regions of a space such as a 180 degree viewing angle. For example, a first diffuser  136  may provide a “batwing” type diffusion pattern, wherein most of the light is directed to the sides, and less light is directed below or in front of the lighting system  100 . A second diffuser  136  may provide a spotlight effect. A third diffuser  136  may provide a patterned effect. 
       FIG. 5  illustrates a typical installation in which a junction box containing line voltage wiring is recessed above a ceiling surface. 
     Turning now to  FIG. 6 , it illustrates a mounting plate or mounting fixture  202  that, unless otherwise described, is substantially similar or identical to the mounting fixture  102  previously described herein. The mounting fixture  202 ,  102  may be attached to a mounting surface, such as, for example, a ceiling, wall, floor, stair, or any other surface, and may be coupled to or configured to be coupled to one or more power source conduits  212 ,  214  on the mounting surface. The one or more conduits  212 ,  214  may be both the entrance and the continuation of a source of power and illustrate the several ways in which conduits  212 ,  214  may be attached to the mounting fixture  204  of the lighting system  200 . The mounting fixture  202  may be removably or permanently attached to the mounting surface with screws, bolts, nails, glue, and/or any other fasteners now known or as yet to be developed. 
     Of note, power cables or wires are not depicted in the figures for simplicity; however, those skilled in the art will understand that the conduits  212 ,  214  may house or support one or more power cables or wires. Holes  184  may be present on all sides (or a subset of the sides) of the mounting fixture  202 , such as four side, or more, or less to allow a variety of configurations for the wiring. The mounting fixture  202  may include an extrusion with mounting brackets attached to either end  208 ,  210  with fasteners. The extrusion permits mounting fixtures of various lengths to be produced from a single extrusion, and common end mounting brackets. 
     Turning now to  FIG. 7 , it illustrates the mounting fixture  202  with support wires or cables attached that mechanically connect the mounting fixture  202  to a light fixture  204  below. This arrangement allows the light fixture  204  to be conveniently supported while the installer attaches electrical wires to the source or performs service on the light fixture  204  such as replacing the batteries in the case of a battery backup fixture. Such a fixture  204  may be configured to turn on automatically when the electrical power has failed. 
       FIG. 8  illustrates a light fixture  204  suspended from a mounting fixture  202  without the mounting fixture  202  present. The electrical connections to the light fixture  204  are shown on the top surface of the light fixture  204 . Also shown on the top surface is a battery (left side) under an enclosure. Mounting of the battery on this surface, together with the support wires, makes it convenient to service the light fixture  204  by removing and replacing the battery. Replacing the battery may be a frequent occurrence. 
       FIGS. 9-10  are exploded views of the light fixture  204  and mounting fixture  202  from below and above respectively. These illustrations show the assembly of the lighting system  200  which may be comprised of an extrusion  234  that serves as a battery  126  and driver  128  tray, and two end caps that support the tray. Another extrusion  232  shown with the remaining end cap attached in each view serves as side rail and a surface onto which a light source  222  (see  FIG. 12 ) such as LEDs are mounted. One of the end caps may be configured to optionally contain a motion or other sensor  264  which is electrically connected to the LED driver  228 . 
     As illustrated most clearly in  FIG. 11 , in some embodiments, two pins  216  are disposed outside the two endcaps. These pins are aligned with the two holes on each end of the mounting bracket assembly. Therefore when the light fixture  204  is pushed up to the mounting fixture  202 , the pins may be pushed in manually, and without the use of tools to fix the light fixture  204  in place by engaging the light fixture  204  with the mounting fixture  202 . 
     Likewise, the pin(s)  216  may be easily withdrawn to free the light fixture  204  for service. The pins may have features that prevent them from falling out of the end caps of the light fixture  204 , such as a tapered profile, a lip or wedge that mates with a corresponding feature of the end cap, and/or a profile that provides a friction force with respect to the end caps. 
       FIG. 12  is an exploded view of the light source that shows the LED PCB which is mounted onto the fixture extrusion of  FIGS. 9-10 . That extrusion, together with the driver tray, forms a channel that holds the LED driver and wires that are connected to the LED PCB. The end caps serve to complete the enclosure. The driver is normally not subject to routine maintenance and so removal is usually required. 
     Turning now to  FIG. 13 , a method  1300  of installing a lighting system is disclosed herein. The method  1300  includes providing  1302  a mounting fixture, providing  1304  a light fixture, providing  1306  a first fastener, removably coupling  1308  the light fixture in an extended configuration, providing  1310  a second fastener, and removably coupling  1312  the light fixture in a retracted configuration. The method  1300  may be performed using any of the lighting systems  100 ,  200  previously disclosed herein. 
     Removably coupling  1308  the light fixture in the extended configuration comprises using the first fastener to removably couple the light fixture. 
     Removably coupling  1312  the light fixture in the retracted configuration comprises using the second fastener to removably couple the light fixture. 
     The method  1300  may include providing a first heatsink for dissipating heat generated by a light source coupled to the light fixture, and/or providing a second heatsink distinct from the first heat sink and for dissipating heat generated by the driver. 
     The method  1300  may include positioning at least a portion of the first heatsink between a light source receptacle and a first side of the driver, wherein the first portion is shaped to define a thermal barrier between the light source and the driver; and wherein providing a second heatsink comprises providing a second heatsink wherein at least a portion of the second heatsink is positioned adjacent a second side of the driver, the second side opposing the first side. 
     The method  1300  may include sliding the first heatsink or the second heatsink onto the other one of the first heatsink or the second heatsink. 
     The terms and expressions employed herein are used as terms and expressions of description and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding any equivalents of the features shown and described or portions thereof. In addition, having described certain embodiments of the invention, it will be apparent to those of ordinary skill in the art that other embodiments incorporating the concepts disclosed herein may be used without departing from the spirit and scope of the invention. For example, while some embodiments of the invention have been described with respect to embodiments utilizing LEDs, light sources incorporating other types of light-emitting devices (including, e.g., laser, incandescent, fluorescent, halogen, or high-intensity discharge lights) may similarly achieve variable beam divergence if the drive currents to these devices are individually controlled in accordance with the concepts and methods disclosed herein. Accordingly, the described embodiments are to be considered in all respects as only illustrative and not restrictive. 
     Each of the various elements disclosed herein may be achieved in a variety of manners. This disclosure should be understood to encompass each such variation, be it a variation of an embodiment of any apparatus embodiment, a method or process embodiment, or even merely a variation of any element of these. Particularly, it should be understood that the words for each element may be expressed by equivalent apparatus terms or method terms—even if only the function or result is the same. Such equivalent, broader, or even more generic terms should be considered to be encompassed in the description of each element or action. Such terms can be substituted where desired to make explicit the implicitly broad coverage to which this invention is entitled. 
     As but one example, it should be understood that all action may be expressed as a means for taking that action or as an element which causes that action. Similarly, each physical element disclosed should be understood to encompass a disclosure of the action which that physical element facilitates. Regarding this last aspect, by way of example only, the disclosure of a “fastener” should be understood to encompass disclosure of the act of “fastening”—whether explicitly discussed or not—and, conversely, were there only disclosure of the act of “fastening”, such a disclosure should be understood to encompass disclosure of a “fastening mechanism”. Such changes and alternative terms are to be understood to be explicitly included in the description. 
     The previous description of the disclosed embodiments and examples is provided to enable any person skilled in the art to make or use the present invention as defined by the claims. Thus, the present invention is not intended to be limited to the examples disclosed herein. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention as claimed.