Patent Publication Number: US-8529096-B2

Title: Mechanical interface for glass bulb for use in solid state light source retrofit lamps

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application claims priority of U.S. Provisional Patent Application Ser. No. 61/252,829, filed Oct. 19, 2009, the entire contents of which are hereby incorporated by reference. 
    
    
     TECHNICAL FIELD 
     The present invention relates to lighting, and more specifically, to mechanically connecting a glass bulb to a solid state light source retrofit lamp. 
     BACKGROUND 
     Glass bulbs have been widely used for incandescent lamps since their initial creation. The process for shaping glass into conventional bulb-shapes (e.g., A19, B10, G25, etc.) and then connecting the bulb to a conventional base (e.g., screw-type base) is well known in the art and has been practiced for over a century. 
     With the advent of solid state light sources (e.g., light emitting diodes (LEDs)), and their use in lighting applications, particularly retrofit applications, bulbs of materials other than glass have typically been used. For example, plastic is sometimes used in retrofit lamps incorporating solid state light sources. Plastic bulbs reduce the weight of a retrofit lamp, which may be considerable, particularly if the lamp includes a metal or primarily metal thermal management system (i.e., heat sink) to dissipate the large amounts of heat generated by the solid state light source(s) within the lamp. Plastic bulbs may also provide greater design flexibility in comparison with glass bulbs. 
     SUMMARY 
     Conventional techniques that use a plastic bulb in place of a glass bulb in a solid state light source retrofit lamp suffer from a variety of deficiencies. Though plastic bulbs may provide greater design flexibility, it is very hard (and costly) to make a plastic bulb that mimics the typical crystallized appearance of a glass bulb, and achieves the same optical and thermal effect. Further, while greater design flexibility may result in a plastic bulb that is, in some aspects, pleasing to look at, consumers frequently want a retrofit lamp that looks very similar, if not the same as, to their existing incandescent lamps. In some instances, a different shape of bulb may not fit appropriately within a given fixture and/or and lamp shade. It is one thing to replace an incandescent bulb with a new retrofit bulb that is more energy efficient and will last far longer. It is another thing to have to replace not just the bulbs, but the entire fixture, or table lamp, or torchiere lamp, or the like. That imposes far greater costs on consumers, and may make consumers less likely to switch to retrofit lamps. 
     Using a glass bulb on a retrofit lamp is, however, not without its own problems. Typically in a retrofit lamp, the glass bulb is glued, or otherwise bonded using a bonding agent, to the rest of the lamp. The bonding process is often a messy procedure, requiring clean up on the exterior and possibly the interior of the lamp. Further, to avoid contaminating the solid state light sources and/or their necessary electrical components (e.g., a driver), as well as other internal components of the lamp, complicates the bonding process. On a high-speed assembly line, this complication may result in having to purchase new, costly equipment that would not be necessary for traditional lamps. 
     Embodiments of the present invention provide various mechanical interfaces to attach a glass bulb to a solid state light source-based retrofit lamp. These embodiments allow for easy attachment of the glass bulb to any retrofit lamp, particularly those that may include a thermal management system (i.e., heat sink) as part of the lamp housing. Should the glass bulb ever break during the long life of the solid state light source, using the invention, the broken glass bulb may be removed and replaced with a new glass bulb. This allows a user to get more life out of an otherwise perfectly useful light source, particularly a light source that may be as expensive as a solid state light source retrofit lamp. In some embodiments, the mechanical interface may be one modular piece of the retrofit lamp, and the removable nature of the glass bulb may allow a user to replace a failed light source within the lamp without having to replace the entirety of an otherwise perfectly useful lamp. Further, in some embodiments, a user may wish to replace a glass bulb of a first type (e.g., a clear glass bulb) with a glass bulb of a second type (e.g., a frosted glass bulb), for a particular application, event, time frame, or the like. Embodiments allow a user this kind of flexibility without having to go to the expense of purchasing a large number of retrofit lamps, one for each different desired application etc. 
     In an embodiment, there is provided a mechanical interface for a glass bulb. The mechanical interface for a glass bulb includes a connector in contact with the glass bulb and an optical mount. The optical mount is configured to receive the connector and, in so receiving, to operatively couple with the connector so as to secure the glass bulb in a position. The optical mount is configured to attach to a lamp housing. 
     In a related embodiment, the connector may include a sleeve, wherein the sleeve may be shaped to fit on a portion of the glass bulb that defines an opening, the sleeve including a connector mechanism to operatively couple with the optical mount. In a further related embodiment, the sleeve may be bonded to the glass bulb. In a further related embodiment, the connector mechanism may be a plurality of posts, wherein at least one post of the plurality of posts may extend radially from the sleeve. 
     In another related embodiment, the connector may be made of glass and may be a continuous part of the glass bulb. In a further related embodiment, the connector may be a plurality of posts, wherein at least one post of the plurality of posts may extend radially from the bulb. In another further related embodiment, the connector may be located near a portion of the glass bulb that defines an opening, the opening to receive a light engine coupled to the lamp housing. 
     In yet another related embodiment, the optical mount may further include a light engine attachment mechanism configured to receive a light engine and to hold the received light engine in a position relative to the glass bulb. 
     In still another related embodiment, the mechanical interface for a glass bulb may further include a base cover, wherein the base cover may be configured to receive the connector and, in so receiving, to operatively couple with the connector so as to secure the glass bulb in a position, and wherein the base cover may be configured to connect to the optical mount, and wherein the optical mount may include an optical mount having a first end and a second end, wherein the second end of the optical mount may be configured to attach to a lamp housing, and wherein the first end of the optical mount may be configured to connect to the base cover. In a further related embodiment, the optical mount may further include a light engine attachment mechanism configured to receive a light engine and to hold the received light engine in a position relative to the glass bulb. 
     In yet still another related embodiment, the optical mount may include a first clamp and a second clamp configured to operatively couple to each other and to receive the connector and, in so receiving, to operatively couple with the connector so as to secure the glass bulb in a position, and wherein the optical mount may be configured to attach to a lamp housing. 
     In another embodiment, there is provided a retrofit lamp. The retrofit lamp includes a lamp housing, a glass bulb, and a mechanical interface for the glass bulb. The lamp housing includes: a light engine including at least one solid state light source; a base configured to connect to a power source; a control circuit coupled to the base and to the light engine, wherein the control circuit is configured to receive power from the power source via the base and to provide the power to the at least one solid state light source of the light engine; and a thermal management system configured to dissipate thermal energy generated within the lamp. The mechanical interface for the glass bulb includes: a connector in contact with the glass bulb; and an optical mount, wherein the optical mount is configured to receive the connector and, in so receiving, to operatively couple with the connector so as to secure the glass bulb in a position, and wherein the optical mount is configured to attach to the lamp housing such that the glass bulb surrounds at least a portion of the light engine. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing and other objects, features and advantages disclosed herein will be apparent from the following description of particular embodiments disclosed herein, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles disclosed herein. 
         FIG. 1  shows an exploded view of a retrofit lamp including a mechanical interface for a glass bulb according to embodiments disclosed herein. 
         FIG. 2  shows a close up view of a glass bulb and portion of a mechanical interface for the glass bulb according to embodiments disclosed herein. 
         FIG. 3  shows a close up exploded view of a glass bulb including a connector, an optical mount, and a lamp housing according to embodiments disclosed herein. 
         FIG. 4  shows a side cross section view of the glass bulb including a connector, the optical mount, and the lamp housing of  FIG. 3 , when these components are attached to each other according to embodiments disclosed herein. 
         FIG. 5  shows a glass bulb and its mechanical interface when attached to each other, but not attached to a lamp housing, according to embodiments disclosed herein. 
         FIG. 6  shows a mechanical interface including an optical mount that is formed from two clamps, according to embodiments described herein. 
         FIG. 7  shows an exploded view of a retrofit lamp including a mechanical interface for a glass bulb according to embodiments described herein. 
     
    
    
     DETAILED DESCRIPTION 
     As used herein, the term “solid state light source” includes one or more light emitting diodes (LEDs), organic light emitting diodes (OLEDs), and the like. As used herein, the term “lamp” refers to a light bulb and thus includes a base (e.g., screw-type, GU24, etc.) to connect the lamp to a socket so as to receive power, a light source, an electrical connection between the base and the light source, and a glass bulb that at least partially surrounds the light source. Depending on the type, a lamp may include further components, such as a fill gas (for an incandescent lamp), a thermal management system (for a solid state light source lamp), a phosphor (for a fluorescent lamp), and the like. The light source may vary depending on the type of lamp. As used herein, the term “light engine” refers to a solid state light source coupled to an optical component, or an electrical component, or both, that is capable of serving as the light source for a lamp. As used herein, the term “post” refers to a protrusion of any size and/or shape that extends in an outward direction and, when placed into an appropriate receptacle, serves to form a mechanical coupling between the component(s) to which it is attached and the receptacle. 
       FIG. 1  shows a solid state light source retrofit lamp  100 . The retrofit lamp  100  is capable of being placed into a conventional lamp socket and receiving power therefrom. The retrofit lamp  100  includes a lamp housing  102 . The lamp housing  102  includes a base  103 , configured to connect to a power source, and a light engine  104 , that itself includes at least one solid state light source. The base  103  may be, but is not limited to, a conventional lamp base configured to connect to a power source. In some embodiments, the base  103  is capable of being connected to a conventional socket that provides power to the retrofit lamp  100 . The light engine  104 , in some embodiments, includes a driver circuit  105 , while in other embodiments, the driver circuit  105  is not part of the light engine  104 . The driver circuit  105  is coupled to the base  103  and to the at least one solid state light source within the light engine  104 , and provides power to the at least one solid state light source of the light engine  104  from the base  103 . The driver circuit  105  may, in some embodiments, include control circuitry to control the at least one solid state light source of the light engine  104  in addition to turning it on and off (i.e., driving it), and may thus also be referred to as a control circuit. The lamp housing  102  may also include a thermal management system that is configured to dissipate thermal energy generated within the retrofit lamp  100 . The thermal management system may be any type of material and/or device that is capable of dissipating thermal energy (i.e., a heat sink). As shown in  FIG. 1 , the thermal management system is part of the lamp housing  102 . 
     The retrofit lamp  100  also includes a glass bulb  106  that surrounds the light engine  104 . The glass bulb  106  is attached to the lamp housing  102  via a mechanical interface  108  for the glass bulb. The mechanical interface  108  includes a connector  110  and an optical mount  112 . The connector  110  serves to mechanically attach the glass bulb  106  to the optical mount  112 , and thus the connector  110  may take any shape and/or form that allows for such a mechanical connection. The connector  110  is in contact with the glass bulb  106 . As shown in  FIG. 1 , and elsewhere, the connector  110  in some embodiments is a separate piece from the glass bulb  106  and must be attached to the glass bulb  106 , as is described in greater detail below. In other embodiments, such as is shown in  FIG. 3 , the connector  110  is made of glass and is a continuous part of the glass bulb  106 . The optical mount  112 , which may have two (or more) parts as shown in  FIG. 1 , or may be a single part as shown for example in  FIG. 3 , is configured to receive the connector  110 . In so receiving the connector  110 , the optical mount  112  operatively couples with the connector  110  so as to secure the glass bulb  106  to the lamp housing  102 , which the optical mount  112  attaches to. Thus, the mechanical interface  108  secures the glass bulb  106  in a particular position, such as but not limited to a position that surrounds the at least a portion of the light engine  104 . In some embodiments, the optical mount  112  additionally includes a light engine attachment mechanism  116 . The light engine attachment mechanism  116  is configured to receive the light engine  104  and to hold the received light engine  104  in a position relative to the glass bulb  106 . The light engine attachment mechanism  116  is thus any type of mechanical connector that is able to hold the light engine  104  in a particular position. 
       FIGS. 2-7  show elements of the mechanical interface  108  of  FIG. 1  in greater detail. In  FIG. 2 , the glass bulb  106  is in contact with the connector  110 . The connector  110  as shown is a sleeve  110  that is shaped to fit on a bottom portion  202  of the glass bulb  106 , wherein the bottom portion  202  defines an opening  204 . The sleeve  110  may be attached to the glass bulb  106  in any known way, such as but not limited to via bonding. Thus, for example, the sleeve  110  may be glued to the glass bulb  106 , affixed via cement, or otherwise attached using a bonding agent. Other known bonding techniques, such as but not limited to fire bonding and the like, may also be used to attach the sleeve  110  to the glass bulb  106 . The sleeve  110  includes a connector mechanism  206 ,  208  that allows the sleeve  110  and the glass bulb  106  to be coupled with the optical mount. The connector mechanism  206 ,  208  may be any type of connector that forms a mechanical connection between the sleeve  110  (and thus the glass bulb  106 ) and the optical mount. As shown in  FIG. 2 , the connector mechanism  206 ,  208  comprises two posts  206 ,  208  that extend radially from the sleeve  110 . The number of posts may vary depending on the size of the glass bulb  106  and/or the strength of the desired connection between the glass bulb  106  and the sleeve  110 , and the optical mount. Thus, in some embodiments, a single post may be all that is required to attach the glass bulb  106  to the optical mount. In some embodiments, the posts  206 ,  208  may be of the same and/or similar shape and/or size, while in other embodiments, the posts  206 ,  208  may be of different shape and/or size. Such a configuration may allow the glass bulb  106  and the sleeve  110  to be attached to the optical mount in only one way, to guarantee that the glass bulb  106  takes a particular position in relation to the lamp housing, light engine, etc. 
       FIG. 3  shows a close up of an exploded view of a glass bulb  106 , an optical mount  112 , and a lamp housing  102 . Here, the glass bulb  106  does not have a separate connector, such as the sleeve  110  shown in  FIG. 2 . Rather, in  FIG. 3  the connector is made of glass and is a continuous part of the glass bulb  106 , such that it is not a separate component. When the connector is part of the glass bulb  106 , the connector may take any shape that allows for mechanical coupling between the glass bulb  106  and the optical mount  112 . As shown in  FIG. 3 , the connector is two posts  210 ,  212  extending radially from the glass bulb  106 . The two posts  210 ,  212  may, as with the posts  206 ,  208  in  FIG. 2 , be of any size and/or shape, including being the same, similar, or different. Of course, as with the posts  206 ,  208  in  FIG. 2 , a single post may be all that is required to attach the glass bulb  106  to the optical mount  112 . The two posts  210 ,  212  are located near a portion  213  of the glass bulb  106  that defines an opening  214 . The opening  214  is to receive a light engine, such as the light engine  104  shown in  FIG. 1 , that is coupled to a lamp housing, such as the lamp housing  102  shown in  FIG. 1 . 
     The optical mount  112  shown in  FIG. 3 , as with the optical mount  112  shown in  FIG. 1 , is configured to receive the two posts  210 ,  212 . Thus, in  FIG. 3 , the optical mount  112  includes two openings  216 ,  218 , into which the two posts  210 ,  212  fit. The glass bulb  106 , and the two posts  210 ,  212  that are part of the glass bulb  106 , are then rotated within a groove  220  so that the two posts  210 ,  212  are not in line with the two openings  216 ,  218 . Thus, the glass bulb  106  is secured in a position. In receiving the two posts  210 ,  212 , the optical mount  112  is operatively coupled with the two posts  210 ,  212 . This is seen most clearly in the cross-section view of  FIG. 4 , where the glass bulb  106 , the optical mount  112 , and the lamp housing  112  are all operatively connected together. The two posts  210 ,  212  rest within the groove  220  of the optical mount  112 , securing the glass bulb  106 . Referring back to  FIG. 3 , the optical mount  112  itself is attached to the lamp housing  112  via two long housing posts  222 ,  224 , though of course any number of housing posts, or any other suitable attachment mechanism, may be used. As seen in  FIG. 4 , the two long housing posts  222 ,  224  may, in some embodiments, serve a dual purpose of connecting the optical mount  112  to the lamp housing  102  and assisting to retain the glass bulb  106  in a particular position once the glass bulb  106  is attached to the optical mount  112 . In some embodiments, the two long housing posts  222 ,  224  may additionally prevent the glass bulb  106  from being removed from the lamp housing  102  without first removing the optical mount  112  from the lamp housing  102 . Thus, in some embodiments, as shown in  FIG. 5 , it is possible to remove the glass bulb  106  and the mechanical interface  108  (including the connector  110 , whatever its form and however it is in contact with the glass bulb  106 , and the optical mount  112 ) from the lamp housing  102  without damaging the retrofit lamp and/or the light engine contained therein. 
     In  FIG. 6 , the optical mount  112  is divided into two clamps  302 ,  304 . The two clamps  302 ,  304  are configured to operatively couple both to each other and to the lamp housing  102 . As with any optical mount  112 , the two clamps  302 ,  304  are configured to receive the connector  110  and, in so receiving, to operatively couple with the connector  110  so as to secure the glass bulb  106  in a position. Of course, in some embodiments, the optical mount  112  may be divided into more than two clamps. The two clamps  302 ,  304  may be hinged or otherwise movable around the glass bulb  106  and the connector  110  when coupled together in at least one place, and then may be coupled in a second place when the glass bulb  106  is to be secured. The two clamps  302 ,  304  may thus adjust depending on the size and/or shape of the glass bulb  106 , such that any number of different sizes and/or shapes of glass bulbs may be used with the same lamp housing  102 . Further, the two clamps  302 ,  304  may also receive any number of different types of connectors, such that two different sized and/or shaped glass bulbs do not each have to have the same connector in order to be coupled to the same lamp housing  102 . 
       FIG. 7  shows the optical mount  112  divided into two pieces, a base cover  402  and an optical mount  404 . The base cover  402  is configured to receive the connector  110  and, in so receiving, to operatively couple with the connector  110  so as to secure the glass bulb  106  in a position. The base cover is also configured to connect to the optical mount  404 . The base cover  402  provides an extra layer of connection for the glass bulb  106 . This improves the strength of the connection between the glass bulb  106  and the optical mount  112 . It also allows the optical mount  112  to be adapted so as to connect to the glass bulb in a first way, via the base cover  402 , that may be particularly suited for that connection, and to also connect to the lamp housing  102  in a second way, via the optical mount  404 , that may particularly suited for that connection. Simultaneously, or in some embodiments, additionally, the base cover  402  may act as a cover for the portion of the lamp housing  102  nearest to the glass bulb  106 , concealing the optical mount  404  as well as the internal components of the retrofit lamp. Thus, the optical mount  404 , in  FIG. 7 , has a first end  406  and a second end  408 . The second end  408  is configured to attach to the lamp housing  102 . The first end  406  of the optical mount  404  is configured to connect to the base cover  402 . In some embodiments, the optical mount  404  may further include a light engine attachment mechanism  116  configured to receive a light engine (not shown in  FIG. 7 ) and to hold the received light engine in a position relative to the glass bulb  106 . 
     Though  FIGS. 1-7  herein have shown a glass bulb in a conventional candelabra-style shape, of course any shape and/or size of glass bulb may be used with embodiments of the mechanical interface as described herein without departing from the scope of the invention. 
     Unless otherwise stated, use of the word “substantially” may be construed to include a precise relationship, condition, arrangement, orientation, and/or other characteristic, and deviations thereof as understood by one of ordinary skill in the art, to the extent that such deviations do not materially affect the disclosed methods and systems. 
     Throughout the entirety of the present disclosure, use of the articles “a” and/or “an” and/or “the” to modify a noun may be understood to be used for convenience and to include one, or more than one, of the modified noun, unless otherwise specifically stated. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. 
     Elements, components, modules, and/or parts thereof that are described and/or otherwise portrayed through the figures to communicate with, be associated with, and/or be based on, something else, may be understood to so communicate, be associated with, and or be based on in a direct and/or indirect manner, unless otherwise stipulated herein. 
     Although the methods and systems have been described relative to a specific embodiment thereof, they are not so limited. Obviously many modifications and variations may become apparent in light of the above teachings. Many additional changes in the details, materials, and arrangement of parts, herein described and illustrated, may be made by those skilled in the art.