Patent Publication Number: US-2015078016-A1

Title: Anti-theft collar for an led light bulb having cooling fins

Description:
BACKGROUND 
     1. Field 
     The present disclosure relates generally to an anti-theft system for a light emitting diode (LED) bulb, and more specifically to an anti-theft collar that engages the cooing fins of an LED bulb to prevent the LED bulb&#39;s removal from a light fixture. 
     2. Description of Related Art 
     Light-emitting diode (LED) bulbs have emerged as a practical and attractive solution for residential and commercial lighting applications. In general, LED bulbs are characterized as being an energy-efficient and long-lasting alternative to incandescent and fluorescent light bulbs. Some LED bulbs have a form factor similar to a standard incandescent bulb, facilitating interchangeability with existing lighting fixtures. One example of an LED bulb that can be used with a standard light-bulb socket is provided in U.S. Pub. No. US2013/0010480, which is incorporated by reference herein in its entirety. 
     As the use of LED bulbs becomes more widespread, it may be appropriate to address concerns with potential theft or unauthorized removal of LED bulbs. Factors such as cost, durability, and visual appeal may lead to a greater risk of theft for some LED bulbs as compared to traditional (non-LED) light bulbs, which are relatively inexpensive and ubiquitous. For example, while LED bulbs offer long-term energy and cost savings and require less frequent replacement, LED bulbs typically have a higher initial cost as compared to traditional incandescent bulbs. Additionally, some LED bulbs may be perceived as novel and produce aesthetically pleasing light. 
     The risk of theft may be particularly high for LED bulbs that are installed in hotels, offices, or public areas that have minimal supervision. Most traditional light-bulb fixtures are not designed to prevent theft of an installed light bulb. In fact, many traditional light-bulb fixtures include an Edison screw socket or bayonet mount that are designed for ease of light bulb installation and removal. Accordingly, there is a need for a device that can deter or prevent removal of an LED light bulb from the socket of a light fixture. 
     BRIEF SUMMARY 
     An exemplary embodiment is directed to a collar for preventing removal of an LED bulb installed in a socket housing of a light fixture. The LED bulb has a plurality of cooling fins to dissipate heat created by the LEDs. The collar includes a wall portion configured to enclose at least a portion of the socket housing. The collar also includes an upper portion that extends from a first end of the wall portion. The collar also includes a pair of ribs extending inward from an inner surface of the upper portion of the collar. The ribs are configured to mechanically engage with at least one fin of the LED light bulb and to inhibit rotation of the LED light bulb with respect to the collar when the collar is installed. 
     In some embodiments, an opening is formed in the wall portion. The opening is configured to at least partially encircle a key of the light fixture when the collar is installed to inhibit rotation of the collar with respect to the light fixture by mechanically engaging with the key. 
     In some embodiments, a lower portion extends from a second end of the wall portion. The lower portion has an upper surface configured to engage with an opposing lower surface of the socket housing to inhibit motion of the collar in a direction along a central axis of the LED bulb. In some embodiments, the collar includes a lower portion instead of an opening to inhibit movement of the collar with respect to the socket housing. 
     In some embodiments, the collar is formed from two pieces that are configured to be mechanically joined by one or more mechanical interlocks. The two pieces may or may not be symmetric or identical to each other. In some embodiments, each mechanical interlock includes at least one tab portion on a first of the two pieces, and at least one slot portion on a second of the two pieces. The tab portion and the slot portion are configured to interlock with each other. In some cases, the tab portion includes a beveled leading edge to facilitate installation and the tab portion includes a catch barb to inhibit removal of the collar after installation. In some cases, the collar is formed from more than two pieces. 
     In some cases, the pair of ribs are perpendicular to the inner surface of the upper portion. The pair of ribs may be separated by a gap that is approximately the width of one cooling fin of the plurality of cooling fins. The thickness of the ribs may be less than the uniform gap between each of the plurality of cooling fins. 
    
    
     
       DESCRIPTION OF THE FIGURES 
         FIG. 1  depicts an exemplary collar installed on a lighting fixture. 
         FIG. 2  depicts an exemplary collar that includes a lower portion. 
         FIG. 3  depicts a partial view of one piece of an exemplary collar installed on a socket housing. 
         FIG. 4  depicts an exemplary LED bulb having cooling fins. 
         FIGS. 5A-B  depict two pieces of exemplary collar having a mechanical interlock for joining the pieces together. 
         FIG. 6A  depicts a top view of one piece of an exemplary collar. 
         FIG. 6B  depicts a top view of one piece of an exemplary collar. 
         FIG. 6C  depicts a top view of two pieces of an exemplary collar coupled by a mechanical interlock. 
     
    
    
     DETAILED DESCRIPTION 
     The following description is presented to enable a person of ordinary skill in the art to make and use the various embodiments. Descriptions of specific devices, techniques, and applications are provided only as examples. Various modifications to the examples described herein will be readily apparent to those of ordinary skill in the art, and the general principles defined herein may be applied to other examples and applications without departing from the spirit and scope of the various embodiments. Thus, the various embodiments are not intended to be limited to the examples described herein and shown, but are to be accorded the scope consistent with the claims. 
     The system described herein is directed to an anti-theft collar configured to prevent an LED bulb from being removed from the socket housing of a lighting fixture. The anti-theft collar specially configured for installation with an LED bulb having an array of cooling fins located around the base of the LED bulb. As described in more detail below with respect to  FIG. 4 , the cooling fins typically facilitate the dissipation of heat generated by the LEDs through passive convection with the surround air. The cooling fins of the LED bulb assist in removing heat from the LED bulb, which may prevent overheating of the LEDs and help extend the life of the components of the LED bulb. 
     1. Anti-Theft Collar 
       FIG. 1  depicts an exemplary (anti-theft) collar installed on a lighting fixture. As shown in  FIG. 1 , the collar  100  can be used to secure an LED bulb  200  having an array of cooling fins ( 221 ,  222 ,  223 ) located on the base  210  of the LED bulb  200 . In this example, the cooling fins ( 221 ,  222 ,  223 ) perform dual functions: first, the cooling fins ( 221 ,  222 ,  223 ) facilitate dissipation of heat generated by the LEDs, and second, the cooling fins ( 221 ,  222 ,  223 ) provide a mechanical engagement for securing the LED bulb  200  using the collar  100 . 
     In this example, the cooling fins ( 221 ,  222 ,  223 ) mechanically engage with the collar  100 , when it is installed around a socket housing  310  of a lighting fixture. As shown in  FIG. 1 , the collar  100  includes a wall portion  102  having a cylindrical shape enclosing the socket housing  310 . As explained in more detail below, the cooling fins ( 221 ,  222 ,  223 ) mechanically engage with the collar  100  to impede rotation of the collar  100  with respect to the LED bulb  200 . As explained in more detail below, the collar  100  also includes one or more features that impedes motion between the collar  100  (and LED bulb  200 ) with respect to the lighting fixture, thereby preventing removal of the LED bulb  200 . 
     In this case, the collar  100  is formed from two semi-cylindrical pieces that are joined together using multiple mechanical interlocks  112 . As described in more detail below with respect to  FIGS. 6A-C , the mechanical interlocks  112  include a tab-in-slot configuration to facilitate installation on a lighting fixture after an LED bulb  200  has been screwed into the socket housing  310 . The mechanical interlocks also include a locking feature that prevents or deters removal of the collar  100  after it has been installed. 
     As shown in  FIG. 1 , the collar  100  includes an upper portion  104  that extends from one end of the wall portion  102 . In this case, the upper portion is tapered outward to accommodate the base  210  of the LED bulb  200 , which is generally cone-shaped. The upper portion  104  typically extends beyond the top of the socket housing  310  and at least partially encloses the base  210  of the LED bulb  200 . The upper portion  104  in this example overlaps a portion of the cooling fins ( 221 ,  222 ,  223 ), but also leaves a significant portion of the cooling fins ( 221 ,  222 ,  223 ) exposed to the surrounding air. This helps to minimize the impact of the collar  100  on the cooling fin&#39;s function as a passive convective cooling element. In some cases, the upper portion  104  leaves more than 50% of the cooling fin surface area exposed to the surrounding air when the collar  100  is installed on the LED bulb  200 . In some cases, the upper portion  104  leaves more than 75% of the cooling fin surface area exposed to the surrounding air when the collar  100  is installed on the LED bulb  200 . In some cases, the upper portion  104  leaves more than 90% of the cooling fin surface area exposed to the surrounding air when the collar  100  is installed on the LED bulb  200 . 
     The upper portion  104  includes at least one rib ( 121 ,  122 ) located on the inner, bulb-facing surface. As shown in  FIG. 1 , the ribs ( 121 ,  122 ) extend inward toward the LED bulb  200 . In this example, the upper portion  104  includes two pairs of ribs, the pairs located approximately 180 degrees from each other. Only one pair ( 121 ,  122 ) are visible in the view depicted in  FIG. 1 . The ribs ( 121 ,  122 ) are configured to mechanically engage with one or more cooling fins ( 221 ,  222 ,  223 ) of the LED bulb  200  when the collar  100  is installed, thereby preventing rotation of the LED bulb  200  with respect to the collar  100 . In this case, each rib ( 121 ,  122 ) is formed from a protrusion that extends from and is substantially perpendicular to the inner surface of the upper portion  104  of the collar  100 . In this example, each rib of the pair of ribs ( 121 ,  122 ) is approximately the same thickness as one or more of the cooling fins ( 221 ,  222 ,  223 ). 
     The pair of ribs ( 121 ,  122 ) are separated by a gap that is approximately the width a cooling fin ( 221 ,  222 ,  223 ) on the LED bulb  200 . In some cases, the gap is slightly smaller than the width of a cooling fin  221  resulting in a slight deformation of the ribs ( 121 ,  122 ) when the collar  100  is installed on the LED bulb  200 . This enhances the mechanical engagement between the cooling fin  221  and the collar  100  and also eliminates play between the two elements. In other cases, the gap between the pair of ribs ( 121 ,  122 ) may be slightly larger than the width of the cooling fin  221 . A gap that is slightly larger ensures that the cooling fin  221  will fit within the gap between the pair of ribs ( 121 ,  122 ) while accounting for normal variations in size due to manufacturing tolerances. 
     The thickness of the rib ( 121 ,  122 ) (width of the protrusion) is approximately the same as the gap between each of the cooling fins ( 221 ,  222 ,  223 ) on the LED bulb  200 . More specifically, the thickness of the rib ( 121 ,  122 ) is slightly less than the gap between each of the cooling fins ( 221 ,  222 ,  223 ). This ensures that the rib ( 121 ,  122 ) will fit between the cooling fins ( 221 ,  222 ,  223 ) given variations in size due to manufacturing tolerances. If the rib ( 121 ,  122 ) is slightly narrower than the gap between the cooling fins ( 221 ,  222 ,  223 ), the mechanical engagement between the rib ( 121 ,  122 ) and the cooling fins ( 221 ,  222 ,  223 ) may be enhanced. In some cases, the thickness of the rib is at least 90% of the gap between the cooling fins. In some cases, the thickness of the rib is at least 95% of the gap between the cooling fins. 
     In the example depicted in  FIG. 1  the pair of ribs ( 121 ,  122 ) are configured to mechanically engage with three cooling fins ( 221 ,  222 ,  223 ) on the LED bulb  200 . Specifically, both ribs ( 121 ,  122 ) are configured to mechanically engage a central cooling fin  222  that is located between the pair of ribs ( 121 ,  122 ) when the collar  100  is installed around the LED bulb  200 . The right rib  122  is also configured to mechanically engage a first adjacent cooling fin  223  that is located to the right of pair of ribs ( 121 ,  122 ) when the collar  100  is installed around the LED bulb  200 . The left rib  121  is also configured to mechanically engage a second adjacent cooling fin  221  that is located to the left of pair of ribs  121 , 122  when the collar  100  is installed around the LED bulb  200 . 
     By way of example, either side of either rib ( 121 ,  122 ) may come in contact or mechanically engage with an adjacent cooling fin ( 221 ,  222 ,  223 ), depending on the position of the collar  100  with respect to the LED bulb  200 . For example, if the collar  100  is rotated slightly clockwise with respect to the LED bulb  200 , a left-facing side of the rib  121  may come in contact with the adjacent cooling fin  221  located to the left of the rib  121 . If the collar  100  is rotated slightly counter-clockwise with respect to the LED bulb  200 , a right-facing side of the same rib  121  may come in contact with the central cooling fin  222  to the right of the rib  121 . This allows each rib ( 121 ,  122 ) to mechanically engage with multiple cooling fins ( 221 ,  222 ,  223 ) to further prevent the collar  100  from rotating with respect to the LED bulb  200 . 
     In the present example, the rib ( 121 ,  122 ) is formed from a protrusion having a rectangular cross section. The walls of the rib ( 121 ,  122 ) are tapered slightly inward (less than 5 degrees) to facilitate installation on the cooling fin  221  of the LED bulb  200 . The drafted walls of the rib ( 121 ,  122 ) may also facilitate manufacturing the collar using injection molding techniques. In other examples, the rib ( 121 ,  122 ) may be formed from a protrusion having walls that are tapered more than 5 degrees. A more steeply tapered rib ( 121 ,  122 ) may acts as a wedge between the cooling fins  221  when installed, further enhancing the mechanical engagement between the collar  100  and the LED bulb  200 . 
     As shown in  FIG. 1 , the collar  100  also includes an opening  106  formed in the wall portion  102 . In general, the opening  106  includes a void or hole in the wall portion  102  of the collar  100 . A key of the light fixture may protrude through the opening  106  when the collar  100  is installed. The key  312  may include, for examples, a turn knob that is used to control the power and/or power level supplied to the LED bulb  200 . In other examples, the key may include a push/pull-type switch for controlling the power to the LED bulb  200 . The opening  106  in the wall portion  102  serves two purposes. First, the opening  106  permits external access to the key. Second, the opening  106  is configured to mechanically engage with the key to prevent rotation of the collar  100  with respect to the socket housing  310  of the lighting fixture. 
     In this example, the opening  106  is configured to encircle a key when the collar  100  is installed in the socket housing  310 . The opening  106  is substantially oval-shaped and is at least as large as the largest portion of the key, which facilitates installation of the collar  100  without having to remove the key or deform the collar  100 . However, in other embodiments, the opening  106  may only partially encircle the key and have a size that is slightly larger than a shaft portion of the key. For example, the opening  106  may be formed from a u-shaped channel in the wall portion  102  of the collar  100  that is configured to slide around the key during installation. The size, shape, and location of the opening  106  may vary depending on the configuration of key and socket housing  310 . In some embodiments, the collar  100  may not have a lower opening, if, for example, the collar is used on a light fixture that does not have a key. In this case, the key cannot be used to prevent the collar  100  from rotating with respect to the light fixture  300 . However, for cases where the light fixture does not include a key  312 , the collar  100  may include one or more additional features that prevent the LED bulb  200  from being removed from the light fixture. For example, the lower portion of collar  100  may be configured to engage with a lower surface of the socket housing to prevent the removal of the collar  100  and LED bulb  200  from the lighting fixture. 
       FIG. 2  depicts part of an exemplary collar  400  that includes a lower portion  408  extending from one end of the wall portion  302 . While the collar  400  depicted in  FIG. 2  is installed around a socket housing  310  having a key  312 , the key  312  may not be necessary to inhibit relative motion between the collar  400  and the socket housing  310  of the lighting fixture. In this case, the lower portion  408  is configured to prevent the LED bulb and collar  400  (which are mechanically connected) from being removed from the socket housing  310  of the lighting fixture. Specifically, the lower portion  408  prevents the collar  400  and the LED bulb from being moved along the central axis  250  of the LED bulb and being pulled completely out of the socket housing  310 . In this example, the lower portion  408  is formed from a portion of both pieces of the collar  400  that extend from the bottom edge of the wall portion  402  to form an inverted dome-shaped structure. The lower portion  408  is configured to curve around the bottom of the socket housing  310  of the light fixture when installed. In this example, the lower portion  408  also forms a hole or opening for the passage of wires and/or the post used to connect the socket housing with other parts of the lamp or appliance. In this example, the wall portion  402  and lower portion  408  together completely enclose the socket housing  310 . In an alternative embodiment, the lower portion may be formed from another shape. For example, the lower portion may extend from one end of the wall portion at a 90 degree angle from the wall portion to form a flat-bottomed lower portion. The lower portion may also be formed from one or more finger-like protrusions configured to inhibit motion of the collar along the central axis  250  of the LED bulb. 
     In the example depicted in  FIGS. 2 and 3 , the lower portion  408  is configured to engage with the socket housing  310  to inhibit motion of the collar  400  with respect to the socket housing  310  in a direction along a central axis  250  of the LED bulb. This prevents the collar  400  and LED bulb from being unscrewed and removed from the socket housing  310 . 
       FIG. 3  depicts part of one piece of an exemplary collar  400  installed around a socket housing  310  and LED bulb (not shown in this view). As shown in  FIG. 3 , the collar  400  includes a lower portion  408  that extends from one end of the wall portion  402  to form an inverted dome-shaped structure that encloses the lower portion of the socket housing  310 . The lower portion  408  includes an upper surface  411  that is configured to engage with an opposing lower surface  311  of the socket housing  310  to inhibit motion of the collar in a direction along a central axis of the LED bulb  250 . The engagement between the upper surface  411  of the lower portion  408  and the opposing lower surface  311  of the socket housing  310  prevents the LED bulb and the collar from being removed from the lighting fixture. In this example, the LED bulb is prevented from becoming completely unscrewed from the socket housing  310  because the upper surface  411  of the lower portion  408  comes in contact with the lower surface  311  of the socket housing  310  limiting the movement of the collar  400  with respect to the socket housing  310 . 
     As shown in  FIG. 3 , the lower portion  408  also forms a hole or opening to allow the socket housing  310  to be attached to the rest of the lighting fixture. The hole or opening also allows for wires or other electrical connections to be routed to the socket housing  310 . 
     In an alternative embodiment, the lower portion may not be a fully revolved dome-shaped structure. For example, the lower portion may be formed from two or more finger-shaped structures that extend from the bottom end of the wall structure  402  towards the central axis  250 . In this case, each finger-shaped structure includes an upper surface that is configured to engage with the lower surface of the socket housing to inhibit motion of the collar in a direction along the central axis  250 . 
     2. LED Bulb with Cooling Fins 
     The collar described above is particularly suitable for use with an LED bulb having external cooling fins.  FIG. 4  depicts a finned LED bulb  200  that may be secured using one of the collars ( 100   400 ), described above. As shown in  FIG. 4 , the LED bulb  200  includes a base  210  and a shell  204  encasing the various components of the LED bulb  200 . The shell  204  is attached to the base  210  to form an enclosed volume. An array of LEDs  208  is attached to LED mounts  212  and is disposed within the enclosed volume. 
     The LED bulb  200  includes several components for dissipating the heat generated by the LEDs  208 . For example, as shown in  FIG. 4 , the LED bulb  200  includes one or more LED mounts  212  for mounting the LEDs  208 . The LED mounts  212  may be made of any thermally conductive material, such as aluminum, copper, brass, magnesium, zinc, or the like. Since the LED mounts  212  are formed from a thermally conductive material, heat generated by the LEDs  208  may be conductively transferred to the LED mounts  212 . Thus, the LED mounts  212  may act as a heat-sink or heat-spreader for the LEDs  208 . 
     The LED mounts  212  are attached to the bulb base  210 , thus allowing the heat generated by the LEDs  208  to be conducted to other portions of the LED bulb  200 . The LED mounts  212  and bulb base  210  may be formed as one piece or multiple pieces. The bulb base  210  may also be made of a thermally conductive material and attached to the LED mounts  212  so that heat generated by the LEDs  208  is conducted into the bulb base  210  in an efficient manner. The bulb base  210  is also attached to the shell  204 , and can thermally conduct with the shell  204 . 
     The bulb base  210  includes thermally conductive cooling fins ( 221 ,  222 ,  223 ) arranged radially around the base  210 . Heat generated by the LEDs  208  is transmitted to the cooling fins ( 221 ,  222 ,  223 ) through the LED mounts  212  and the bulb base  210 . The cooling fins ( 221 ,  222 ,  223 ) provide additional surface area that allows heat to be dissipated to the surrounding environment. In this example, the cooling fins ( 221 ,  222 ,  223 ) are configured to facilitate passive convective cooling with the surrounding air by forming multiple (vertical) convective channels. As previously described with respect to  FIG. 1 , the cooling fins ( 221 ,  222 ,  223 ) also provide mechanical engagement between the LED bulb  200  and (anti-theft) collar to inhibit rotation of the LED bulb  200  with respect to the collar. 
     3. Collar Installation and Removal 
     As previously mentioned, exemplary collar  100  is formed from two pieces for installation and removal. To install a two-piece collar, each piece of the collar is typically placed on either side of the base of an LED bulb installed within a light fixture. The pieces of the collar are aligned with cooling fins on the LED bulb so that corresponding ribs on the collar mechanically engage with the LED bulb. Additionally, the pieces of the collar are aligned so that, if the collar includes an opening in the wall portion for a key, the opening aligns with the key on the light fixture to allow the key to protrude through the opening when the collar is installed. 
     The two pieces of the collar are then pressed together around the base of the LED bulb and the light fixture to abut the edges of the two pieces of the collar and engage the mechanical interlocks (described in more detail below with respect to  FIGS. 5A-B  and  6 A-C). When installed in this manner, the collar encloses at least a portion of a socket housing of the light fixture and at least a portion of the base of the LED bulb. The pieces of the collar may be symmetric or have identical geometry. In some cases, the pieces of the collar are not symmetric. Non-symmetric or non-identical geometry may further inhibit the removal of the collar by preventing disengagement of the mechanical interlocks by shifting of the pieces with respect to each other. 
       FIGS. 5A-B  depict two pieces of exemplary collar  100  having a mechanical interlock for joining the pieces. Each piece of the collar  100  includes two tabs  520  and two slots  518 . The tabs  520  on one piece of the collar  100  slide into corresponding slots  518  on the other mating piece of the collar  100  to join and lock the pieces together. The tabs  520  are configured such that they are easy to insert but difficult to disengage once inserted, thus serving as a theft deterrent. In this example, the tabs  520  include a beveled leading edge to facilitate insertion into a corresponding slot  518 . The tabs  520  also include a catch barb that engages with the slot  518  when installed to prevent disassembly of the two pieces. 
     As an additional deterrent, in this example, separation of the two pieces of the collar requires disengagement of multiple tabs  520  at the same time. Simultaneous disengagement may be made more difficult if the two pieces do not have interlocks having exactly the same geometry. For example, the tabs may be slightly offset to prevent the two pieces from being disassembled by merely shifting the pieces. 
       FIGS. 6A-B  depict top views of two pieces of an anti-theft collar when the pieces are separated.  FIG. 6C  depicts a top view of the pieces when they are interlocked by sliding the tabs  520  into the slots  518 . Other types of mechanical interlocks may be used to join the pieces of the collar. These may include, for example, a variety of fasteners, clasps, threaded connectors, or adhesives. In some embodiments, the mechanical interlock may comprise a flexible or inflexible band that encloses the collar. In some embodiments, the mechanical interlock may not be removable. 
     As discussed above, exemplary collar  100  is designed to comprise two pieces to enable installation and removal. However, other collar designs that enable installation and removal are also possible. For example, a collar may comprise more than two pieces that can be locked together and detached from each other. The pieces of the collar may also hinge at one or more joints to enable them to pivot with respect to each other rather than detaching from each other completely. One or more pieces may also be connected to each other by a material or joint that provides for expansion between the sections, such as a flexible mesh or elastic. 
     The anti-theft collar may be fabricated from a variety of materials. These may include, for example, various forms of polycarbonates, metals, woods, or other materials that provide suitable strength and rigidity to prevent cracking or breaking of the collar by hand. The anti-theft collar may be fabricated using an injection molding, a machining, or another fabrication technique. The anti-theft collar may be fabricated from a single type of material, or the collar may be fabricated from multiple materials. For example, the mechanical interlocks may be fabricated from a different material than the walls of the collar, and attached to the collar using an adhesive, fastener, or other bonding technique. 
     The examples above are intended to be illustrative rather than comprehensive. A person having skill in the art will recognize that there are many possible collar designs and materials that will achieve the desired result of preventing removal of an LED bulb from a light fixture.