Patent Publication Number: US-10782001-B2

Title: Light engine retrofit kit for existing light fixtures and associated method

Description:
REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 62/488,221, filed on Apr. 21, 2017, and entitled LIGHT ENGINE RETROFIT KIT FOR EXISTING LIGHT FIXTURES AND ASSOCIATED METHOD, the content of which is hereby incorporated by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     Embodiments of the invention relate to light fixtures, and more particularly to light emitting diode (LED) based light sources for use in existing fluorescent light fixtures. 
     BACKGROUND 
     Traditional light fixtures presently used in a typical office environment comprise a housing with at least one fluorescent lamp and a lens having prismatic elements for distributing the light. Historically, the most commonly used fluorescent lamps in indoor lighting applications have been the linear T5 (⅝ inch diameter), T8 (1 inch diameter), and the T12 (1½ inch diameter). Such bulbs are inefficient and have a relatively short lamp life. Thus, efforts have been made to identify suitable alternative illumination sources for indoor lighting applications. Light emitting diodes (“LEDs”) have been identified as one alternative to traditional fluorescent bulbs. 
     A LED typically includes a diode mounted onto a die or chip, where the diode is surrounded by an encapsulant. However, in comparison to simply changing a light bulb in a conventional light fixture, exchanging an existing fluorescent fixture for a light fixture that uses LEDs as a light source can be labor intensive and costly. Such replacement typically requires access to the area above the ceiling. Environmental concerns, such as asbestos contamination and asbestos removal, become an issue when disturbing the ceiling. Moreover, the area above the ceiling collects dirt and dust, which can dislodge during LED replacement and thereby increase the time and cost of clean-up after installation. Additionally, exposed electrical wiring is common in such areas, which creates a safety hazard for workers removing old fixtures. A licensed electrician may be required to install the new fixtures based upon common safety codes. Thus, businesses and consumers are reticent to invest in a new LED light fixture when the effort and costs are compared to maintaining an existing fluorescent light fixture. 
     Efforts have also been made to retrofit an existing fluorescent light fixture with a LED light source. However, existing fluorescent light fixtures may come in any number of different sizes and configurations. Specifically, LED retrofit kits may not be generally compatible with existing fluorescent light fixtures. Oftentimes, a given LED retrofit kit may only be compatible with existing light fixtures that share a common mounting arrangement. Even if the LED retrofit kit is compatible, it may be difficult to install, particularly for a single worker. Therefore, there exists a need for a LED retrofit kit that is generally compatible with existing light fixtures, and that may be easily installed by a single worker. 
     SUMMARY 
     The terms “invention,” “the invention,” “this invention” and “the present invention” used in this patent are intended to refer broadly to all of the subject matter of this patent and the patent claims below. Statements containing these terms should be understood not to limit the subject matter described herein or to limit the meaning or scope of the patent claims below. Embodiments of the invention covered by this patent are defined by the claims below, not this summary. This summary is a high-level overview of various embodiments of the invention and introduces some of the concepts that are further described in the Detailed Description section below. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used in isolation to determine the scope of the claimed subject matter. The subject matter should be understood by reference to appropriate portions of the entire specification of this patent, any or all drawings, and each claim. 
     According to various examples, a retrofit kit for a light fixture includes a light engine and a mounting bracket. In some examples, the light engine includes a base, a first engine flange at a first side of the base, and a second engine flange at a second side of the base opposite the first side. In certain cases, the first engine flange includes a foldable convenience tab, the second engine flange includes a hook, and the hook is configured to engage the mounting bracket such that the light engine is pivotally supported on the mounting bracket. 
     In various examples, the light engine is movable relative to the mounting bracket between a temporary hanging position, a temporary support position, and a fully-installed position. In some cases, in the temporary hanging position, the hook is engaged with the mounting bracket and the first engine flange is spaced apart from the mounting bracket. In various aspects, in the temporary support position, the hook is engaged with the mounting bracket, the foldable convenience tab is engaged with the mounting bracket, and the base of the light engine is spaced apart from a base of the mounting bracket. In certain examples, in the fully-installed position, the hook and foldable convenience tab are spaced apart from the mounting bracket, and the base of the light engine abuts the base of the mounting bracket. 
     In some aspects, the mounting bracket includes a bracket base, a first bracket flange at a first side of the bracket base, and a second bracket flange at a second side of the bracket base opposite the first side. According to various cases, the foldable convenience tab is configured to selectively engage the first bracket flange and the hook, and, in the fully-installed position, the first engine flange conceals the first bracket flange and the second engine flange conceals the second bracket flange. In certain aspects, the mounting bracket further includes a first mounting flange and a second mounting flange that are configured to support the mounting bracket on a housing of a light fixture. 
     According to some embodiments, the mounting bracket includes a first bracket flange and a second bracket flange, the hook is configured to engage the second bracket flange, and the foldable convenience tab is configured to engage the first bracket flange in a temporary support position such that the light engine is supported by the mounting bracket. In various examples, the hook includes a notch, and the second bracket flange includes a stopping tab that is configured to engage the notch in the temporary support position. In some cases, the light engine further comprises a plurality of light emitting diodes. 
     According to some examples, a method of installing a retrofit kit in a light fixture includes installing a mounting bracket onto a housing of the light fixture and placing a light engine in a temporary hanging position. In various cases, in the temporary hanging position, a hook of a first engine flange of the light engine rests on the mounting bracket and a foldable convenience tab of a second engine flange of the light engine is spaced apart from the mounting bracket. In various cases, placing the light engine in the temporary hanging position includes positioning a stopping tab of a first bracket flange of the mounting bracket in a notch defined by the hook. 
     In certain cases, the method includes pivoting the light engine relative to the mounting bracket such that the light engine is in a temporary support position. In various examples, in the temporary support position, the hook is engaged with the mounting bracket, the foldable convenience tab is engaged with the mounting bracket, and the light engine is vertically movable relative to the mounting bracket. In some aspects, in the temporary support position, the hook is engaged with a first bracket flange of the mounting bracket and the foldable convenience tab is bent and engaged with a second bracket flange of the mounting bracket. In various cases, in the temporary support position, a light engine base of the light engine is spaced apart from a bracket base of the mounting bracket such that a gap is between the light engine and the mounting bracket. 
     According to various examples, the method further includes positioning the light engine in a fully-installed position by securing the light engine to the mounting bracket. In some aspects, in the fully-installed position, a light engine base of the light engine abuts a bracket base of the mounting bracket. 
     According to certain examples, a retrofit kit for a light fixture includes a light engine and a mounting bracket. In certain cases, the mounting bracket includes a pair of bracket flanges at opposing sides of a bracket base and a pair of mounting flanges between the bracket flanges such that a distance between the mounting flanges is less than a distance between the bracket flanges. In some cases, the light engine is supportable on the bracket flanges in a temporary support position, and the mounting flanges are configured to engage a housing of the light fixture such that the mounting bracket is secured to the housing. 
     In various examples, the light engine includes a pair of engine brackets, where a first engine bracket of the pair of engine brackets includes a hook and a second engine bracket of the pair of engine brackets includes a foldable convenience tab. In some cases, in the temporary support position, the hook is engaged with a first bracket flange of the pair of bracket flanges and the foldable convenience tab is engaged with a second bracket flange of the pair of bracket flanges. According to various aspects, the light engine is movable relative to the mounting bracket from the temporary support position to a fully-installed position, and, in the fully-installed position, the hook is spaced apart from the first bracket flange and the foldable convenience tab is spaced apart from the second bracket flange. 
     In certain cases, the light engine is movable relative to the mounting bracket between a temporary hanging position, the temporary support position, and a fully-installed position. In some aspects, in the temporary hanging position, the hook is engaged with the first bracket flange of the mounting bracket and the second engine flange is spaced apart from the second bracket flange. In various cases, in the temporary support position, a base of the light engine is spaced apart from the base of the mounting bracket. In some examples, in the fully-installed position, the hook and foldable convenience tab are spaced apart from the bracket flanges, and the base of the light engine abuts the base of the mounting bracket. According to various aspects, the mounting bracket further includes channel-centering slots configured to receive portions of the housing of the light fixture during installation to position the mounting bracket relative to the housing. In certain examples, the retrofit kit includes a plurality of light emitting diodes on a light-emitting side of the light engine and a lens secured to the light-emitting side of the light engine below the plurality of light emitting diodes. In certain examples, the mounting flanges are bendable relative to the bracket base such that the distance between the mounting flanges is adjustable. 
     Various implementations described in the present disclosure can include additional systems, methods, features, and advantages, which cannot necessarily be expressly disclosed herein but will be apparent to one of ordinary skill in the art upon examination of the following detailed description and accompanying drawings. It is intended that all such systems, methods, features, and advantages be included within the present disclosure and protected by the accompanying claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The features and components of the following figures are illustrated to emphasize the general principles of the present disclosure. Corresponding features and components throughout the figures can be designated by matching reference characters for the sake of consistency and clarity. 
         FIG. 1  is a perspective view of a light engine with a mounting system for retrofitting an existing light fixture according to examples of the present invention. 
         FIG. 2  is a perspective view of the light engine base of  FIG. 1 . 
         FIG. 3  is another perspective view of the light engine base of  FIG. 1 . 
         FIG. 4  is a perspective view of a mounting bracket of the mounting system of  FIG. 1 . 
         FIG. 5  is an end view of the light engine of  FIG. 1  in a temporary hanging position. 
         FIG. 6  is a perspective view of the temporary hanging position of  FIG. 5 . 
         FIG. 7  is an end view of the light engine of  FIG. 1  in a temporary support position. 
         FIG. 8  is an end view of the light engine of  FIG. 1  in an installed position. 
         FIG. 9  is a perspective view of a light engine with a mounting system for retrofitting an existing light fixture according to examples of the present invention. 
         FIG. 10  is a perspective view of the light engine base of  FIG. 9 . 
         FIG. 11  is another perspective view of the light engine base of  FIG. 9 . 
         FIG. 12  is a perspective view of a mounting bracket of the mounting system of  FIG. 9 . 
         FIG. 13  is a perspective view of the light engine of  FIG. 9  in a temporary hanging position. 
         FIG. 14  is another perspective view of the light engine of  FIG. 9  in the temporary hanging position. 
         FIG. 15  is another perspective view of the mounting bracket of  FIG. 4 . 
         FIG. 16  is an enlarged view of the mounting bracket of  FIG. 4  supporting the light engine of  FIG. 2  in a temporary hanging position. 
         FIG. 17  is another enlarged view of mounting bracket of  FIG. 4  supporting the light engine of  FIG. 2  in a temporary hanging position. 
         FIG. 18  is a perspective view of a light engine base of a light engine for retrofitting an existing light fixture according to examples of the present invention. 
         FIG. 19  is an end view of the light engine base of  FIG. 18 . 
     
    
    
     DETAILED DESCRIPTION 
     The subject matter of examples of the present invention is described here with specificity to meet statutory requirements, but this description is not necessarily intended to limit the scope of the claims. The claimed subject matter may be embodied in other ways, may include different elements or steps, and may be used in conjunction with other existing or future technologies. This description should not be interpreted as implying any particular order or arrangement among or between various steps or elements except when the order of individual steps or arrangement of elements is explicitly described. Directional references are intended to refer to the orientation as illustrated and described in the figure (or figures) to which the components and directions are referencing. 
     Traditional light fixtures presently used in a typical office environment comprise a housing and a lens having prismatic elements for distributing the light. Typical light fixtures may also use parabolic reflectors to provide a desired light distribution. A description of such a light fixture may be found in U.S. Pat. No. 7,229,192, the content of which is hereby incorporated by reference. 
     A LED typically includes a diode mounted onto a die or chip, where the diode is surrounded by an encapsulant. The die is connected to a power source, which, in turn, transmits power to the diode. A LED used for lighting or illumination converts electrical energy to light in a manner that results in very little radiant energy outside the visible spectrum. LEDs are extremely efficient, and their efficiency is rapidly improving. For example, the lumen output obtained by 20 LEDs may soon be obtained by 10 LEDs. 
     Embodiments of the present invention relate to a retrofit kit for retrofitting existing light fixtures containing fluorescent or other light sources with light emitting diode (“LED”) based light sources. Some embodiments of the retrofit kit include a light engine, a mounting bracket, and an optional lens. The retrofit kits disclosed herein may be installed in fixture housings of any dimensions, including but not limited to 1×4, 1×8, 2×4, etc. In some examples, a retrofit kit may be configured to accommodate a light fixture having specific dimensions, or it may be provided in a size that generally will fit within most generic existing light fixtures (e.g., it will universally fit with existing light fixtures). In some embodiments, a single retrofit kit is provided in a light fixture. However, it will be appreciated that multiple retrofit kits may be installed in a light fixture. 
       FIGS. 1-8 and 15-17  illustrate an example of a retrofit kit  10  that includes a light engine  12 , a mounting bracket  14 , and a lens  16 . As shown in  FIGS. 1-3 , the light engine  12  includes a light engine base  22  having a light-emitting side  24  and a non-light-emitting side  26 . At least one printed circuit board (“PCB”)  52  (see  FIG. 14 ) populated with a plurality of LEDs  53  (see  FIG. 14 ) is mounted on the light-emitting side  24  of the light engine base  22 . Each PCB can have wiring for connecting to a power supply, which can be shared between PCBs or each PCB could have its own power supply. The LEDs may be single-die or multi-die LEDs, DC, or AC, or can be organic light emitting diodes. White, color, or multicolor LEDs may be used. Moreover, the LEDs mounted on a PCB need not all be the same color; rather, mixtures of LEDs may be used. Furthermore, in some embodiments no PCB is needed; rather, the LEDs are chip-on-board LEDs. In some embodiments, no PCB is needed; rather, the LEDs are chip-on-board LEDs provided directly on the light engine base  22 . In some examples, the light engine base  22  optionally defines at least one captive screw aperture  23  that accommodates a captive screw  40 . 
     The light engine base  22  further includes engine flanges  18 A-B. The engine flanges  18 A-B extend away from the light-emitting side  24  of the light engine base  22 . In some examples, the engine flanges  18 A-B are integrally formed with the light engine base  22 , although they need not be. 
     In some examples, the engine flange  18 A includes a convenience tab  28 . The convenience tab  28  is foldable relative to the engine flange  18 A to aid in retaining the light engine  12  in a temporary support position (see  FIG. 7 ). The number of convenience tabs  28  or location of the convenience tabs  28  along the engine flange  18 A should not be considered limiting on the current disclosure. In some examples, the number and location of the convenience tabs  28  corresponds with a number and location of the mounting brackets  14 , although they need not. In the example illustrated in  FIGS. 1-8 , the engine flange  18 A includes two convenience tabs  28 . 
     In various examples, the engine flange  18 B includes at least one hook  30 . In some examples, the hook  30  is at a position opposite a convenience tab  28 , although it need not be. The number of hooks  30  or the location of the hooks  30  should not be considered limiting on the current disclosure. For example, in some cases, a plurality of hooks  30  or a single hook  30  may be provided at discrete locations along the engine flange  18 B. In some examples, the number of hooks  30  corresponds with the number of convenience tabs  28 , although they need not. For example, in various cases, a single hook  30  may be formed along a length of the engine flange  18 B (see  FIGS. 10 and 11 ). In the embodiment of  FIGS. 2 and 3 , a set of hooks  30  is provided on the engine flange  18 B proximate each end of the light engine  12 . Each set of hooks  30  defines a notch  32 . The notch  32  is configured to receive portions of the mounting bracket  14  to aid in retaining the light engine  12  on the mounting bracket  14 , as described below. 
     The retrofit kit  10  includes at least one mounting bracket  14 . The number or location of the mounting brackets  14  should not be considered limiting on the present disclosure. In the example illustrated in  FIG. 1 , the retrofit kit  10  includes two mounting brackets  14 . 
     As illustrated in  FIG. 4 , the mounting bracket  14  includes a base  34 . In some examples, the base  34  defines channel-centering slots  36  that receive portions of the housing  20  of the light fixture  21  during installation to position the mounting bracket  14  relative to the housing  20 . The number and location of the channel-centering slots  36  may be varied as desired such that the mounting bracket  14  can accommodate a housing  20  having a particular dimension or can accommodate a plurality of housing dimensions. The base  34  further defines a captive screw aperture  38  that receives a captive screw  40  during installation to secure and position the light engine  12  relative to the mounting bracket  14 . 
     Mounting flanges  42 A-B extend from the base  34 . Each mounting flange  42 A-B defines a fastening aperture  54 A-B (see  FIG. 4 ) that receives a fastener  44  to secure the mounting bracket  14  relative to the housing  20 . In certain examples, each mounting flange  42 A-B is foldable or bendable relative to the base  32  such that the mounting flanges  42 A-B can accommodate housings having different dimensions. In various examples, each mounting flange  42 A-B is foldable where the mounting flanges  42 A-B respectively extend from the base  34 . Additionally or alternatively, the each mounting flange  42 A-B may be foldable or bendable along a length of the flange. The fastener  44  may be various fasteners such as screws, bolts, pins, self-tapping screws, rivets, or various other suitable fasteners. In some examples, the fastener  44  is a self-drilling screw. 
     The mounting bracket  14  further includes a set of bracket flanges  46 A-B extending from each side of the base  34 . In some examples, the bracket flanges  46 A-B include upstanding arms  45  and extensions  48  that extend inwardly at non-zero angles from the upstanding arms  45 . In various examples, a stopping tab  50  extends at a non-zero angle from at least one extension  48  of each set of bracket flanges  46 A-B. The stopping tabs  50  are configured to be received within the notches  32  defined by the hooks  30  of the light engine  12 . The stopping tabs  50  may be provided to aid in retaining the light engine  12  in a temporary support position. In some examples, the stopping tabs  50  of the mounting bracket  14  are positionable between hooks  30  of the light engine  12 . In various aspects, such positioning of the stopping tabs  50  restricts longitudinal translation of the light engine  12  during temporary installation (or at a temporary position during installation), which makes the light engine  12  more secure for the installer. In some optional examples, the convenience tabs  28  may be folded by the installer to rest on the extensions  48  and provide a temporary installation position until the installer secures the light engine  12  with fasteners  44 . In some examples, the mounting bracket  14  may be symmetrical to allow for installation of the light engine  12  in 0° or 180° orientations. As one non-limiting examples, both sides of the mounting bracket  14  may include extensions  48  and/or stopping tabs  50 . However, in other examples, the mounting bracket  14  need not be symmetrical. As one non-limiting example, one side of the mounting bracket  14  includes extensions  48  and/or stopping tabs  50  while the other side does not. The mounting bracket  14  is symmetrical in the illustrated embodiments; however, such need not be the case in all embodiments. 
     As shown in  FIG. 1 , some embodiments of the retrofit kit also include a lens  16 . The lens  16  is positioned over the LEDs on the light-emitting side  24  of the light engine  12 , and may serve both as an aesthetic cover and to functionally direct or diffuse light to provide better lighting conditions. The lens  16  may be of any type (diffuse, prismatic, etc.) and any shape that achieves the desired light distribution from the light fixture  21 . In various examples, the lens  16  may be mounted on the light engine  12  through mechanical fasteners (such as screws, self-tapping screws, pins, bolts, rivets, or other mechanical fastening devices), a snap-fit arrangement, or various other suitable fastening mechanisms. As illustrated in  FIGS. 18 and 19 , in some optional examples, light engine  12  includes the PCB  52  attached to a separate lens retention component  55  that is connected to the light engine base  22 . In such a case, the lens  16  may attach to flanges  57 A-B of the component  55  (rather than directly to the light engine base  22 ). Various other configurations of the light engine base  22 , PCB  52 , and lens  16  may be provided. 
       FIGS. 5-8 and 15-17  illustrate various stages of installation of the light engine  12  into the existing light fixture  21 . Prior to installation, the existing light fixture  21  is stripped of its existing light elements and their associated wiring and electronics. The method of stripping the existing light fixture  21  will vary depending upon the particular type of light elements, their associated hardware and electrical connections, and the configuration of the existing light fixture  21 . Generally, the process for removal of the lighting elements from an existing light fixture  21  will include: (i) removing electrical power from the existing light fixture  21 ; (ii) disconnecting any lighting elements and associated hardware from the existing light fixture  21 ; and (iii) removing unnecessary brackets or hardware, if any. The existing light fixture  21  is then in a bare condition and ready for the installation of the light engine  12 . 
     After the existing light fixture  21  has been stripped, the mounting brackets  14  may be installed into the housing  20  of the existing light fixture  21  by positioning edges of the housing  20  within the channel-centering slots  36  of the mounting brackets  14 . The fasteners  44  (e.g., self-tapping screws, bolts, pins, rivets, etc.) are installed through the mounting flanges  42 A-B to secure the mounting brackets  14  relative to the housing  20 . 
     Once the mounting brackets  14  are installed in the housing  20 , the light engine  12  may be placed in a temporary hanging position (see  FIGS. 5 and 6 ). In the temporary hanging position, the hooks  30  of the engine flange  18 B of the light engine  12  wrap around bracket flanges  46 B. When so positioned, the hooks  30  rest upon the extensions  48  of the bracket flange  46 B and the stopping tab  50  of each bracket flange  46 B is positioned within the notch  32  defined by the hooks  30 . Engagement of the hooks  30  with the bracket flanges  46 B creates a hinge that supports the light engine  12  in the temporary hanging position, and the light engine  12  may freely hang from the mounting brackets  14  without any additional support. Positioning of the stopping tabs  50  within the notches  32  prevents relative sliding between the light engine  12  and mounting brackets  14  (and thus also the light fixture  21 ). The positioning of the hooks  30  on the extensions  48  of the mounting bracket  14  prevents the light engine  12  from being disengaged from the mounting bracket  14 . 
     In the temporary hanging position, the engine flange  18 A is spaced apart from the bracket flange  46 A such that an installer may access the non-light-emitting side  26  and/or within the housing  20 . In various examples, the installer may position the light engine  12  in the temporary hanging position while electrical connections are made on the light engine  12  and/or within the housing  20 . 
     After the electrical connections are made, the light engine  12  is rotated or pivoted about the hinge formed between the hooks  30  and the bracket flanges  46 B and into the temporary support position (see  FIG. 7 ). In the temporary support position, the light engine  12  is supported by the mounting bracket  14  but is not mechanically secured to the mounting bracket  14 . As illustrated in  FIG. 7 , in the temporary support position, the engine flange  18 A is adjacent to the bracket flange  46 A, and the convenience tabs  28  are bent (e.g., by the installer manually or with a tool) such that the convenience tabs  28  overlap portions of the extensions  48  of the bracket flange  46 A. In some examples, the convenience tabs  28  may abut extensions  48  of the bracket flange  46 A, although they need not. As illustrated in  FIG. 7 , in the temporary support position, the captive screw  40  is engaged in the captive screw aperture  23  in the light engine base  22  but is not yet engaged with the captive screw aperture  38  of the mounting bracket  14 . In some examples, in the temporary support position, the light engine base  22  is spaced apart from the base  34  of the mounting bracket  14  such that a gap is between the light engine  12  and the mounting bracket  14 . 
     As illustrated in  FIG. 8 , to fully install the light engine  12 , the installer engages the captive screw  40  with the captive screw aperture  38  such that, upon further tightening of the captive screw  40 , the light engine base  22  is drawn towards to the base  34 . In some cases, the light engine base  22  abuts the base  34  in the fully-installed position, although it need not. Compared to the temporary support position, in the fully-installed position, the light engine  12  is mechanically secured to the mounting bracket  14  (e.g., through the captive screw  40 ). 
     Optionally, in some examples, the engine flanges  18 A-B are dimensioned such that when the light engine  12  is in the fully-installed position, the engine flanges  18 A-B overlap or substantially overlap the bracket flanges  46 A-B. By overlapping the bracket flanges  46 A-B, the engine flanges  18 A-B hides or substantially hides the bracket flanges  46 A-B from view when viewed from the light-emitting side  24 . 
     Referring to  FIGS. 9-14 , another example of a retrofit kit  100  is illustrated. Similar to the retrofit kit  10 , the retrofit kit  100  includes a light engine  112 , a bracket  114 , and the lens  16 . 
     The light engine  112  is similar to the light engine  12  except that the engine flange  18 B includes a single, continuous hook  130  extending along a length of the light engine  112  (see  FIGS. 10 and 11 ). The continuous hook  130  defines notched hook portions  132  for receiving portions of the mounting bracket  114  to limit sliding movement of the light engine  112  relative to the mounting brackets  114  and light fixture  21 . 
     The mounting bracket  114  is similar to the mounting bracket  14  except that the mounting bracket  114  does not include the extensions  48  and stopping tabs  50  that extend from the upstanding arms  45 . 
     As illustrated in  FIGS. 9, 13, and 14 , during installation of the light engine  112 , in the temporary hanging position, the notched hook portions  132  wrap around the upstanding arms  45  of the bracket flanges  46 A-B such that the light engine  112  may freely hang from the mounting bracket  114  without any additional support. Portions of the upstanding arms  45  are positioned behind the hook  130  to further aid in supporting the light engine  112  in the temporary hanging position. In some examples, a combination of the base  34  and the upstanding arms  45  may limit longitudinal movement or maintain the longitudinal position of the light engine  12  relative to the light fixture  21  in at least one direction because the base  34  will interfere with the longitudinal movement of the hook  130 . Such engagement may prevent the light engine  112  from disengaging from the mounting bracket  114  and releasing the light engine  112 . 
     In the temporary support position, the convenience tabs  28  are bent such that the convenience tabs  28  overlap portions of the upstanding arms  45  of the bracket flanges  46 A. In some examples, the convenience tabs  28  optionally wrap around bracket flanges  46 A, although they need not. 
     Different arrangements of the components depicted in the drawings or described above, as well as components and steps not shown or described are possible. Similarly, some features and sub-combinations are useful and may be employed without reference to other features and sub-combinations. Examples of the invention have been described for illustrative and not restrictive purposes, and alternative examples will become apparent to readers of this patent. Accordingly, the present invention is not limited to the examples described above or depicted in the drawings, and various examples and modifications may be made without departing from the scope of the claims below.