Abstract:
A lamp assembly includes an inner assembly that has a CFL source, an electronics board, and a holder that interconnects the CFL source and electronics board. An outer, light transmissive envelope surrounds the inner assembly and various fixing arrangements are disclosed for securing the inner assembly to the outer envelope. Three primary mechanisms are a ratchet mechanism, a spring mechanism, or using adhesive to secure the inner assembly to the outer envelope under a predetermined tension.

Description:
BACKGROUND OF THE DISCLOSURE 
     Cross-reference is made to commonly-owned, co-pending application Ser. No. 12/151,414, filed simultaneously herewith, entitled “HOLDER FOR INTEGRAL COMPACT FLUORESCENT LAMP WITH OUTER BULB” and Ser. No. 12/181,419, filed simultaneously herewith, entitled “ELECTRIC LAMP WITH INNER ASSEMBLY AND OUTER BULB AND METHOD FOR MANUFACTURING”. 
     This disclosure relates to a lamp assembly, and more particularly to a compact fluorescent lamp (CFL) assembly of the type having an outer envelope or bulb that encloses the lamp and the associated electronics therein. The disclosure may find use in related environments so that particular aspects may have application, for example, as alternative ways to generally secure a CFL and associate electronics to a lamp base. 
     More recent developments in CFL assemblies include incorporation of an outer bulb or envelope about the CFL source. It is desired that the associated electronics or printed circuit board (PCB) that drives the CFL be incorporated into an integrated unit. That is, the electronics board is typically enclosed within a housing or shell that is axially positioned between the CFL source and a threaded base. In those designs where the CFL includes a series of interconnected, inverted U-shaped tubes, the overall diameter of the CFL source is generally narrow and thus the upper end of the shell that interconnects with a surrounding light transmissive envelope allows the CFL to be inserted through the open end of the outer envelope. Even then, the shell typically tapers or reduces to a neck or flare of a narrower dimension at an opposite end for connection with a mechanical and electrical connection and an associated socket that receives same. For example, it is common to have a threaded base, sometimes referred to as an Edison-style base, although pin type or plug-in type connections are also alternatively used. 
     In many instances, it is desired that a narrow end of the A-line-shaped outer envelope, i.e., the necked-down, smaller diameter portion region toward the base of the lamp, be sized smaller than the minimum lateral dimension of the CFL. By way of example, a helical CFL has first and second ends that extend generally longitudinally or parallel to a lamp axis, while an intermediate portion forms one or more helical turns in an effort to maximize a length of a discharge path between the first and second ends of the CFL. It often becomes necessary to cut the outer envelope generally along the maximum diameter portion and insert the CFL source into the cut envelope. Thereafter, the outer envelope is re-sealed along the cut line of the envelope to enclose the CFL. 
     It will be appreciated that minimizing the number of components and labor intensive handling of components inserted into the outer envelope is desirable for ease of manufacture. That is, once the outer envelope is cut in two pieces, it is desirable that the inner components be inserted and fixed in position in an inexpensive, repeatable, reliable manner. 
     Moreover, as noted above, where the CFL and other components cannot be inserted through the narrow end of the outer envelope, the separated portions of the outer envelope must be cut and re-sealed. The re-sealing process exposes the installed components to elevated temperatures. Accordingly, there is a need not only for locating the inner lamp components in the outer envelope and fixedly securing them within the envelope, but there is also a need to thermally protect the sensitive electronic components on the electronics board during the re-sealing process. 
     It will be further appreciated that the neck or flare portion of the outer envelope has surface irregularities. Thus, attempts to secure inner components to the remainder of the lamp assembly have focused on alternative structures and manners of attachment. 
     Accordingly, a need exists for fixing or securing an inner assembly that includes a CFL source to an outer envelope in an effective, repeatable, and inexpensive manner. 
     SUMMARY OF THE DISCLOSURE 
     An improved mechanism for fixing an inner assembly including a CFL source to an outer bulb is disclosed. 
     The lamp assembly includes an inner assembly having a compact fluorescent light (CFL) source, an electronics board, and a holder interconnecting the CFL source and the electronics board. An outer light transmissive envelope surrounds at least the light source. Fixing means is provided for interconnecting the inner assembly to the outer envelope. 
     The fixing means includes at least one of an adhesive, ratchet mechanism, or spring assembly. 
     The spring assembly includes a first portion connected to the inner assembly and a second portion connected to the outer envelope. In the preferred form, the spring second portion engages an end of the envelope. 
     Preferably, the spring is in tension and urges the inner assembly toward an end of the envelope. 
     The ratchet assembly includes a base plate dimensioned to overlie a first end of the envelope having an opening that receives a ratchet member therethrough that is connected to the inner assembly. A first toothed portion of the ratchet assembly selectively engages a second toothed portion associated with the base plate opening. 
     The lamp assembly may have application without an outer envelope where a CFL light source and electronics board are interconnected to one another via a holder. A base is configured for electrical and mechanical connection with an associated socket, and means for fixing the holder to the base is provided. 
     A primary benefit of this disclosure relates to a new fixing mechanism for securing the inner assembly to an outer bulb. 
     A fixing means eliminates the last degree of freedom of the inner assembly. 
     The fixing means adapts to a flare portion of the outer envelope that typically has irregularities from one glass envelope to another. 
     The fixing means provides both locating assistance and thermal protection for the electronics board during re-sealing of the glass envelope. 
     Still other features and benefits of the present disclosure will become apparent from reading and understanding the following detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a lamp assembly that includes an inner assembly housed within an outer envelope. 
         FIG. 2  is an enlarged perspective view of the inner assembly illustrating a lower portion of a CFL source received in a holder that is secured to an electronics board. 
         FIG. 3  is a longitudinal cross-section of the lamp assembly of  FIG. 1 . 
         FIG. 4  is a cross-sectional view similar to  FIG. 3 , but rotated through ninety degrees (90°). 
         FIG. 5  is an enlarged cross-sectional view of a ratchet assembly for fixing the inner assembly to an outer envelope. 
         FIG. 6  is a view similar to  FIG. 5 , but rotated through ninety degrees (90°). 
         FIG. 7  is a perspective view of the lower portion of the lamp assembly illustrating the ratchet assembly for fixing the inner assembly to an outer envelope. 
         FIG. 8  is a perspective view in partial cross-section similar to  FIG. 7 , but rotated through approximately ninety degrees (90°). 
         FIG. 9  is an enlarged elevational view of a ratchet member. 
         FIG. 10  is an elevational view of the ratchet member of  FIG. 9  taken from the right-hand side of  FIG. 9 . 
         FIG. 11  is a cross-sectional view of the ratchet member of  FIG. 10 , taken generally along the lines  11 - 11  thereof. 
         FIG. 12  is a plan view of a base plate. 
         FIG. 13  is an elevational view of the base plate of  FIG. 12 . 
         FIG. 14  is a plan view of the underside of the base plate of  FIG. 12 . 
         FIG. 15  is a plan view of a ratchet cap. 
         FIG. 16  is a cross-sectional view taken generally along the lines  16 - 16  of  FIG. 15 . 
         FIGS. 17 through 20  are views illustrating use of the ratchet member to fix the inner assembly to the outer envelope. 
         FIG. 17  is a perspective view of a spring assembly for fixing the inner assembly to the outer envelope. 
         FIG. 18  is a plan view of the spring and outer envelope of  FIG. 17 . 
         FIG. 19  is an elevational view, shown partially in cross-section, of the spring assembly for securing the inner assembly to the outer envelope. 
         FIG. 20  is a perspective view of the spring member used in the embodiments of  FIGS. 17-19 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Shown in  FIG. 1  is a lamp assembly  100  that includes an inner assembly  102  having a light source  104  and electronics member or board, often referred to as a printed circuit board (PCB)  106 , and a holder  108  that interconnects the light source and the electronics board so that the inner assembly can be handled as a sub-assembly. Enclosing the inner assembly is an outer envelope or bulb  120  which is preferably a light transmissive material such as glass that encloses an inner cavity dimensioned to receive the inner assembly therein. More particularly, the outer envelope adopts the general conformation of an A-line lamp that has an enlarged generally spherical portion  122  at one end and a flare or neck portion  124  at the other end interconnected with the spherical portion by tapering region  126 . The outer envelope has a generally constant wall thickness that terminates in an opening at a first end  128  disposed adjacent a conventional electrically conductive base  140 , shown here as a threaded Edison base  140 . The threaded base is separated from an end contact  142  by an insulating material  144 . The base, and particularly the contact  142  and threaded region  140  thereof, are received in an associated lamp socket (not shown) to establish electrical and mechanical connection of the lamp assembly. Of course, other lamp bases such as conventional plug-in type connections that establish mechanical and electrical connection between the lamp assembly and an associated electrical socket can be used without departing from the scope and intent of the present disclosure. 
       FIG. 2  more particularly illustrates the inner assembly  102 , although the entire light source is not shown for ease of illustration. The light source as illustrated here is a compact fluorescent lamp (CFL)  150  that includes first and second ends or legs  152 ,  154  that extend generally parallel to one another and in a longitudinal direction that is generally parallel to a central lamp axis of the lamp assembly  100 . These legs house the electrodes at opposite ends of an elongated discharge path that includes each leg and an intermediate discharge path which in this embodiment is a helical or spiral lamp arrangement  156 . 
     The legs are received in the holder  108 , which more particularly includes a platform  170  that includes first and second openings  172 ,  174  that closely receive legs  152 ,  154  of the CFL, respectively. The platform further includes an outer tapered perimeter  176  that substantially conforms to the tapered region  126  of the outer envelope. Disposed adjacent the tapered perimeter  176  is a shoulder  178  that receives a resilient ring or sealing O-ring  180  to slidably and sealingly engage with the inner surface of the tapering region  126  of the outer envelope. The tapered perimeter and O-ring provides for desired positioning and location of the inner assembly  102  within the outer envelope. Preferably, the holder is formed of a heat-resistant material such as plastic and has sufficient rigidity and strength to provide a stable mounting of the CFL within the outer envelope. Further, the holder includes a passage  182  ( FIG. 4 ) that communicates between a first or upper side  184  and a second or lower side  186 . The passage  182  is provided to supply pressurized fluid, such as air, during a re-sealing process of the outer envelope which will be more particularly described below. 
     Extending from the second side  186  of the holder are circumferentially spaced legs  188  ( FIG. 3 ). The legs preferably have retaining shoulders  190  dimensioned for snap-fit engagement with the electronics board  106  via legs  200  having similar retaining shoulders  202  on the electronics board that cooperate with the retaining shoulders  190 . The electronics board also includes a disk or platform  204  that includes a slot  206  to receive a vertically extending portion of the PCB which carries various electrical components  210 . It will be appreciated that the component is merely illustrative of one electrical component that may be disposed on the electronics board, and should not be intended to limit the construction. For example, other electrical components  212  may be disposed on an upper surface of the platform  204  to allow ease of connection with the legs  152 ,  154  of the CFL source. 
     The inner assembly  102 , as generally illustrated in  FIG. 2 , and as embodied into the lamp assembly as shown in  FIGS. 3 and 4 , may be pre-assembled as a sub-assembly. As is apparent from  FIGS. 3 and 4 , the diameter of the CFL source  150  is larger than the diameter or transverse dimension of the neck portion  124  of the outer envelope. In order to assemble the lamp, it becomes necessary to cut the outer envelope  120  into first and second portions  120   a ,  120   b  along separation or parting plane  220 . Once separated, the inner assembly  102  is inserted by directing the electronics board end initially inward into the lower portion  120   b  of the outer envelope. Once the inner assembly is fixed or retained in secured relation in a manner to be described below, the outer envelope is re-sealed along the plane  220  to define a one-piece outer envelope again. 
     As a part of the outer envelope arrangement, it becomes necessary to secure or fix the inner assembly thereto. This disclosure describes three preferred ways to accomplish fixing of the inner assembly to the outer envelope. With continued reference to  FIGS. 1-4 , attention is directed to  FIGS. 5-8  which illustrate a first preferred arrangement generally referred to as a ratchet assembly or ratchet mechanism  250 . The ratchet assembly includes a first ratchet member  252 , which in the preferred arrangement is a generally elongated, generally L-shaped component having an enlarged head  254  at one end and a toothed portion  256  extending along the elongated leg thereof. The enlarged head  254  ( FIGS. 9-11 ) has a dimension greater than opening  258  provided in a vertically extending portion  208  of the electronics board. In this manner, the L-shaped ratchet member  252  is extended through the opening until the enlarged head  254  abuts adjacent the opening  258 . This provides a secure connection between the first ratchet member  252  and the inner assembly. The elongated leg of the first ratchet member is then received through a support member  260  and particularly, a central opening  262  therein ( FIGS. 5-8  and  12 - 14 ). The support member has a maximum dimension adapted to abuttingly engage against the first, lower end  128  of the outer envelope. A first surface  264  includes a central boss  266 , while the opposite face  268  includes a locating means such as a cruciform-shaped arrangement  270  that is dimensioned for receipt within the inner diameter of the first end of the outer envelope. In addition to the ratchet member  252  and the support member  260 , the ratchet assembly  250  further includes a toothed insert  280  that includes an irregular perimeter  282 , such as a polygon shape, that conforms to the opening  262  in the support member  260 . The insert  280  further includes a toothed portion  284  that extends at least partially into passage  286  for selective cooperative engagement with the toothed portion  256  of the ratchet member  252  ( FIGS. 5-8  and  15 - 16 ). 
       FIGS. 17-20  illustrate a second mechanism, hereinafter referred to as a “spring assembly”, for fixing the inner assembly to the outer envelope. More particularly, the opening  258  in the vertical portion of the electronics board is advantageously used to grab or grip the inner assembly and urge the inner assembly inwardly into the outer envelope. The spring mechanism  300  is configured so that spring  302  is preferably a single-piece construction that has a first portion that engages the inner assembly, and a second portion that engages the outer envelope and imparts a spring force or tension on fixing the inner assembly to the outer envelope. That is, a first leg  304  of the spring has an enlarged loop  306  with a necked-down region  308  received through the opening  258  in the electronics board. Thus, the loop  306  is oriented for insertion through the opening in the electronics board, and the entire spring then rotated through ninety degrees (90°) so that the loop prevents inadvertent removal of the spring from the electronics board. The loop may also have a slightly upturned configuration ( FIG. 19 ) for further retention capabilities as the inner assembly is inserted or advanced toward the neck of the outer envelope. As will be appreciated, the overall lateral dimension of the spring is preferably maintained less than the opening in the first end  128  of the outer envelope. In this manner, the inner assembly with the spring attached as described above can be fed toward the narrowed opening in end  128 . The second portion or second leg  310  of the spring is actually formed as separate legs for symmetry reasons and for evenly distributing the forces imposed on the inner assembly. Thus, reverse loop portions  312  terminate in elongated legs  310 . As is apparent in  FIGS. 17-19 , the second legs are dimensioned to extend across the entire opening at the first end  128  of the outer envelope when the spring is positioned in a generally perpendicular relation to the lamp axis or, stated another way, when the second legs are generally disposed in plane or in abutting engagement with the first end of the outer envelope. The reverse loop portions  312  extend beyond the periphery of the first end of the envelope, while the linear leg portions terminate generally diametrically opposite and also beyond the perimeter of the first end of the outer envelope. In this manner, the first leg  304  of the spring has a natural tendency to seek to be in plane with the second leg portions  310 . This provides the tension or inward pulling force on the inner assembly and seats the O-ring and tapered portion of the holder against the inner surface of the outer envelope. 
       FIG. 20  demonstrates that spring  302 ′ can adopt a slightly different variation where the linear leg portions  310  include curved ends  316 . Otherwise, the spring  302 ′ of  FIG. 20  is substantially identical in structure and function to that shown relative to  FIGS. 17-19 . 
     A third manner of fixing the inner assembly to the outer envelope is also contemplated. Specifically, this arrangement provides for a glue or an adhesive solution to fix the inner assembly to the outer envelope. Preferably, a two-component silicon or hot-melt adhesive is used. The hot-melt adhesive is placed in a cup and base of the outer envelope at the same time and a twisting action undertaken between the two so that at a temperature of approximately 200° C., the adhesive is spread about the perimeter of the electronics board. Once the adhesive cools, the adhesive becomes solid and maintains the tension between the electronics board and the base portion of the outer envelope. If desired, the hook or wire can provide a temporary pulling force on the inner assembly to hold the inner assembly in a desired location until the adhesive cures. 
     It is also contemplated that these fixing features be potentially used with the lamp base and without an outer envelope. Thus, any of the fixing methodologies described above, that is, the ratchet mechanism, the spring mechanism, or the adhesive arrangement by which the inner assembly is fixed to the outer envelope may find application in securing the CFL source, holder, and electronics board to the remainder of a lamp base. 
     In summary, a new lamp assembly includes a special inner structure that requires a new fixing mechanism for the inner assembly to the outer bulb or envelope. Preferably, fixing is accomplished via the electronics board. In the torsion spring arrangement, the spring is attached to the electronics boards of the ballast assembly through a hole, and another portion of the spring aligns to a base circumference of the outer envelope. 
     In the ratchet arrangement, the base plate aligns to a base circumference of the outer envelope. The base plate and the electronics board are then attached to each other by an L-shaped ratchet ribbon/rod. The ratchet base may be part of the plate or a separate element. 
     In the adhesive arrangement, the glue/adhesive filled base is attached to the outer envelope where the electronics board is partially embedded in the glue. As a result of this fixing of the inner assembly to the outer envelope, a last degree of freedom of the inner assembly is fixed. Testing shows that a pull force of 30 to 100 Newtons is obtained and less than 10 Newtons is likely needed. 
     The disclosure has been described with reference to the preferred embodiments. Obviously, modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended that the invention be construed as including all such modifications and alterations.