Patent Publication Number: US-10788165-B1

Title: End cap assembly, lamp using the end cap and assembling method of the lamp

Description:
BACKGROUND 
     Embodiments of the present disclosure relate generally to a lamp, and more particularly relate to a light emitting diode (LED) lamp and its end cap assembly. 
     Conventional incandescent bulbs and halogen bulbs energize resistance wires and heat filaments to very high temperature to produce visible light. A structure typically includes a transparent glass envelope, a filament, a glass stem with a sealed wire, and a base. Although such lamps are relatively inexpensive and have a light distribution close to full angle, their lifetime and energy efficiency are not high. In recent years, LED lamps have many advantages such as high energy efficiency, long life, compact size and environmental protection. It has been proposed to combine LED light sources with traditional glass bulbs to achieve superposed advantages. 
     If a LED light source and a driving module are directly disposed inside the traditional glass bulb. When the LED lamp is working, some electronic components inside the glass bulb, such as the driving module, will generate a certain heat to make packaging materials, solders, insulation materials, adhesive etc. thereon emit some volatile organic compound (VOC) particles. These volatile organic compound particles may be deposited on a surface of the high-temperature LED chip, which reduces a luminous efficiency of the LED chip on one hand. On the other hand, the deposit affects the heat dissipation of the LED chip, the LED chip is used in a high-temperature environment for a long time, thereby reducing its life and stability. An existing method is arranging the LED light source inside the sealed glass bulb, and the driving module is disposed inside an end cap of the LED lamp to be isolated from the LED light source. However, for high-power LEDs, such as 100 W LEDs, the heat generated by the driving module disposed inside the end cap cannot be dissipated, which affects the life of the driving module. 
     Therefore, it is desirable to provide an end cap assembly to address one or more of the above-mentioned situations. 
     BRIEF DESCRIPTION 
     In accordance with one embodiment disclosed herein, an end cap assembly includes an end cap, an isolation module, a mounting module, a conductive contact, a driving module and a potted material. The end cap defines therein an end cap interior chamber. The isolation module includes a first end coupled to the end cap and a second end having a first opening. The mounting module is coupled to the isolation module and at least partially accommodated in the first opening, and the mounting module has a second opening, wherein an area of the second opening is smaller than that of the first opening. The conductive contact is at least partially accommodated in the second opening. The driving module is at least partially accommodated in the end cap interior chamber and electrically connected with the end cap and the conductive contact respectively. The potted material is filled in the end cap interior chamber and surrounds at least part of the driving module. 
     In accordance with another embodiment disclosed herein, a lamp includes a lighting device and an end cap assembly. The lighting device includes an envelope and at least one lighting unit. The end cap assembly includes an end cap, an isolation module, a mounting module, a conductive contact, a driving module and a potted material. The end cap defines therein an end cap interior chamber. The isolation module includes a first end coupled to the end cap and a second end having a first opening. The mounting module is coupled to the isolation module and at least partially accommodated in the first opening, and the mounting module has a second opening, wherein an area of the second opening is smaller than that of the first opening. The conductive contact is at least partially accommodated in the second opening. The driving module is at least partially accommodated in the end cap interior chamber and electrically connected with the end cap and the conductive contact respectively, the driving module is configured to convert and provide electrical energy received from the end cap and the conductive contact to the at least one lighting unit. The potted material is filled in the end cap interior chamber and surrounds at least part of the driving module. 
     In some embodiments, the lighting device further includes a support module accommodated in a first interior chamber being formed between the envelope and the end cap, the support module is configured to support the at least lighting unit and comprises a second interior chamber having a third opening. 
     In some embodiments, the end cap assembly further includes a block module accommodated in the end cap interior chamber and coupled to the third opening of the support module to block the third opening for preventing the potted material from flowing into the second interior chamber from the end cap interior chamber. 
     In some embodiments, the block module is made of a material including a plastic or a rubber. 
     In some embodiments, the first opening includes at least one slot configured to clamp at least one hook on the mounting module and corresponding thereto. 
     In some embodiments, the first opening of the isolation module is a substantially circular hole, and the diameter of the circular hole is about from 5.5 to about 18 mm. 
     In some embodiments, the potted material includes a moldable heat conductive glue selected from acrylate thermal conductive adhesive, vinyl ester resin thermal conductive adhesive, silicone thermal conductive adhesive, thermal conductive silicone grease, epoxy thermal conductive adhesive, phenolic resin thermal conductive adhesive, polyurethane thermal conductive adhesive and combinations thereof. 
     In accordance with yet another embodiment disclosed herein, a method for assembling a lamp, the lamp includes at least one lighting unit, an envelope, an end cap, an isolation module, a mounting module and a driving module. The method includes electrically connecting the driving module with the at least one lighting unit and the end cap, respectively; accommodating at least part of the driving module in an end cap interior chamber of the end cap; coupling the end cap to the envelope of the lamp to make the driving module be accommodated in a first interior chamber formed between the envelope and the end cap; filling a potted material into the end cap interior chamber from a first opening of the insulation module coupled to the end cap, to make the potted material surround at least part of the driving module; coupling the mounting module of the lamp to the first opening of the insulation module; and coupling a conductive contact to a second opening of the mounting module and electrically connecting the conductive contact to the driving module, wherein an area of the second opening is smaller than that of the first opening. 
     In some embodiments, the method further includes accommodating a block module in the end cap interior chamber and coupling the block module to a support module of a lighting device for preventing the potted material from flowing into the support module from the end cap interior chamber. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated herein and form part of the specification, illustrate the present disclosure and, together with the description, further serves to explain the principles of the disclosure and to enable a person skilled in the relevant art(s) to make and use the disclosure. 
         FIG. 1  is a perspective view of an LED lamp according to an embodiment of the present disclosure; 
         FIG. 2  is an exploded view of the LED lamp shown in  FIG. 1 ; 
         FIG. 3  is a top view of a combination f an end cap and an insulation module of the LED lamp shown in  FIG. 1 ; 
         FIG. 4  is a perspective view of a mounting module of the LED lamp shown in  FIG. 1 ; 
         FIG. 5  is a top view of the LED lamp shown in  FIG. 1 ; 
         FIG. 6  is a cross-section view of the LED lamp taken along line A-A of  FIG. 5 ; and 
         FIG. 7  is a flow chart of a method for assembling a lamp according to an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Unless defined otherwise, technical and scientific terms used herein have the same meaning as is commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terms “first”, “second”, and the like, as used herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. Also, the terms “a”, and “an” do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced items. The use of “including,” “comprising” or “having” and variations thereof herein are meant to encompass the items listed thereafter and equivalents thereof as well as additional items. The terms “connected” and “coupled” are not restricted to physical or mechanical connections or couplings, and can include electrical connections or couplings, whether direct or indirect. 
       FIG. 1  and  FIG. 2  show a perspective view and an exploded view of one embodiment of an LED lamp  10 , respectively. As shown in  FIGS. 1 and 2 , the lamp  10  includes a light device  200  and an end cap assembly  100  coupled to the light device  200 . The light device  200  includes an envelope  202  and at least one lighting unit  204 . 
     In some embodiments, as shown in  FIG. 1 , the envelope  202  has a hollow structure, and the envelope  202  can be identical in shape to an existing incandescent lamp, including a substantially spherical top and a substantially hollow cylindrical bottom at the lower end of the top. In an unlimited embodiment, the envelope may also be shaped as a candle, a cylinder, an inverted cone, or the like. The light device  200  further includes a support module  206  and a circuit board  210  accommodated in a first interior chamber  212  being formed between the envelope  202  and the end cap assembly  100 . Wherein, the support module  206  is configured to support the circuit board  210  and the at least lighting unit  204  disposed on the circuit board  210 . In some other embodiments, the lighting unit  204  in the lighting device  200  may be a filament structure or other circuit board arrangement. The envelope  202  may be made of a light transmissive material. In some embodiments, the envelope  202  is made of transparent glass, and the support module  206  is a glass stem. The bottom of the support module  206  is coupled to the envelope  202  through high temperature melting. In some other embodiments, the envelope  202  can also be made of a transparent plastic or a transparent ceramic. 
     As shown in  FIG. 2 , the end cap assembly  100  includes an end cap  102 , an insulation module  104 , a mounting module  106 , a conductive contact  108 , a driving module  116  and a potted material  118 . One end of the end cap  102  is bonded to the envelope  202  by a low temperature solder and an end cap interior chamber  124  is formed in the end cap  102 . The other end of the end cap  102  is coupled to a first end of the insulation module  104 . A second end of the insulation module  104  away from the end cap  102  has a first opening  110 . In some embodiments, the end cap  102  may be made of a conductive metal material, and the insulation module  104  may be made of a plastic material by injection molding, wherein the insulation module  104  is coupled to the end cap  102  by bonding. In some embodiments, the end cap  102  further includes a threaded outer surface. 
       FIG. 3  is a top view of a combination of the end cap  102  and the insulation module  104  of the LED lamp  10  shown in  FIG. 1 . The mounting module  106  is coupled to the insulation module  104  and at least partially accommodated in the first opening  110 . The mounting module  106  has a second opening  112 , wherein the area of the second opening  112  is smaller than the area of the first opening  110 . 
     Further referring to  FIG. 2 , the conductive contact  108  is at least partially accommodated in the second opening  112 . In some embodiments, the metal pin  109  of the conductive contact  108  is inserted into the second opening  112  of the mounting module  106 , and a diameter of the second opening  112  is corresponding with a diameter of the metal pin  109 . 
     In some embodiments, as shown in  FIGS. 3 and 4 , the first opening  110  of the insulation module  104  is a substantially circular hole having a diameter of 5.5-18 mm, which is convenient for injecting the potted material into the end cap interior chamber  124  through the first opening  110 . The first opening  110  is circumferentially arranged with four slots  114  for clamping the four hooks  146  on the mounting module  106  corresponding with the four slots. In some other embodiments, the shape of the first opening  110  may be other shapes which are equivalent to the size of the circular opening. The slots  114  and the hooks  146  can be replaced with other connecting structures which can be easily installing and disassembling, and the number of the slots  114  and the corresponding hooks  146  are not limited therein, and may be any number including 2, 3 or more than 4. The slot-hook structure connecting the insulation module  104  and the mounting module  106  facilitates installation and disassembly without the use of an adhesive, saving the assembly time. 
       FIG. 5  is a top view of the LED lamp  10  shown in  FIG. 1 .  FIG. 6  is a cross-sectional view of the LED lamp  10  taken along line A-A of  FIG. 5 . Referring to  FIG. 2  and  FIG. 6 , the support module  206  includes a pair of metal pins  216 . One end of the support module  206  is electrically connected to the circuit board  210  via the metal pins  216 , the lighting unit  204  is mounted on the circuit board  210 , and the other end of the support module  206  is electrically connected to the driving module  116  to power the lighting unit  204 . At least part of the driving module  116  is accommodated in the end cap interior chamber  124 . The driving module  116  includes a pair of metal pins  126 ,  136  electrically connected to the end cap  102  and the conductive contact  108 , respectively, the driving module  116  is configured to convert and provide electrical energy received from the end cap  102  and the conductive contact  108  to the lighting unit  204 . 
     Further referring to  FIG. 6 , the potted material  118  is filled in the end cap interior chamber  124  and surrounds at least part of the driving module  116  for reducing the contact thermal resistance generated between a heat source surface and a heat sink member contact surface and transferring heat generated by the driving module  116  to the end cap  102  to assist in heat dissipation. The potted material  118  includes a moldable heat conductive glue selected from acrylate thermal conductive adhesive, vinyl ester resin thermal conductive adhesive, silicone thermal conductive adhesive, thermal conductive silicone grease, epoxy thermal conductive adhesive, phenolic resin thermal conductive adhesive, polyurethane thermal conductive adhesive and combinations thereof. 
     In some embodiments, the support module  206  includes a second interior chamber  236  having a third opening  208 . As shown in  FIG. 2 , the end cap assembly  100  further includes a blocking module  120 . The blocking module  120  is accommodated in the end cap interior chamber  124  and coupled to the third opening  208  of the support module  206  to block the third opening  208  for preventing the potted material  118  from flowing into the second interior chamber  236  from the end cap interior chamber  124 . In some embodiments, the size of the blocking module  120  is substantially equal to the size of a base of the support module  206 , and the blocking module  120  can cover the transparent base of the support module  206  to prevent the driving module  116  or the potted material  118  in the end cap assembly  100  from being viewed through the support module  206 , make the lighting device more aesthetically. Wherein, the blocking module  120  is made of a material including a plastic or a rubber. 
     A method for assembling the LED lamp  10  according to one embodiment of the present disclosure will be described below referring to  FIGS. 2 and 6 .  FIG. 7  is a flow chart of a method for assembling the lamp according to an embodiment of the present disclosure, the method  700  includes: 
     In step  710 , electrically connecting the driving module  116  with the at least one lighting unit  204  and the end cap  102 , respectively. 
     In step  720 , accommodating at least part of the driving module  116  in an end cap interior chamber  124  of the end cap  102 . Wherein, the support module  206  is configured to support the circuit board  210  and the plurality of lighting units  204  disposed on the circuit board  210 . The driving module  116  is electrically connected to the lighting unit  204  through the support module  206  disposed between the driving module  116  and the circuit board  210 . In some embodiments, the blocking module  120  is accommodated in the end cap interior chamber  124  and coupled to the support module  210  of the envelope  202  for preventing the potted material  118  from flowing into the support module  210  from the end cap interior chamber  124 . 
     In step  730 , coupling the end cap  102  to the envelope  202  of the lamp  10  to make the driving module  116  be accommodated in the first interior chamber  212  formed between the envelope  202  and the end cap  102 . 
     In step  740 , the lamp  10  is placed perpendicular to the ground in a manner that the end cap  102  on top and the envelope  202  on the bottom. The step  740  further including filling the potted material  118  into the end cap interior chamber  124  from the first opening  110  of the insulation module  104  coupled to the end cap  102 , to make the potted material  118  surround at least part of the driving module  116 . The potted material  118  includes a moldable heat conductive glue selected from acrylate thermal conductive adhesive, vinyl ester resin thermal conductive adhesive, silicone thermal conductive adhesive, thermal conductive silicone grease, epoxy thermal conductive adhesive, phenolic resin thermal conductive adhesive, polyurethane thermal conductive adhesive and combinations thereof. The penetration of the heat conductive glue can better and faster transfer the heat generated by the driving module  116  into the end cap  102  and an external environment. 
     In step  750 , after the potted material is substantially cured, coupling the mounting module  106  of the lamp  10  to the first opening  110  of the insulation module  104 . In some embodiments, the mounting module  106  is clamped the slots  114  of the insulation module  104  by the hooks  146  for easily installation and removal, saving assembly time. 
     In step  760 , coupling a conductive contact  108  to the second opening  112  of the mounting module  106  and electrically connecting the conductive contact  108  to the driving module  116 , wherein the area of the second opening  112  is smaller than that of the first opening  110 . A size of the second opening  112  is the same as a size of the standard metal pin  109  of the conductive contact  108 . The positive and negative electrodes of the driving module  116  are electrically connected to the end cap  102  and the metal pin  109 , respectively. 
     As can be seen from the above implementations, the present disclosure accommodates the driving module in the end cap interior chamber of the end cap. After coupling one end of the end cap to the envelope of the lamp, the potted material with a heat conduction function is injected into the end cap interior chamber from the other end of the end cap. The heat dissipation of the driving module can be achieved while avoiding the influence of the potted material on the bonding of the end cap and the lamp envelope. Moreover, the end cap assembly of the present disclosure is designed with a structure can easily install and disassemble the insulation module and the mounting module structure. Firstly, the first opening of the insulation module is advantageous for potting and reducing assembly time; secondly, the size of the second opening of the mounting module can be designed the same as the size of the standard conductive contact, which avoids the redesign of the conductive contact and reduces the cost. 
     While embodiments of the disclosure have been described herein, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the disclosure. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the disclosure without departing from the essential scope thereof. Therefore, it is intended that the disclosure not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this disclosure, but that the disclosure will include all embodiments falling within the scope of the appended claims. 
     Furthermore, the skilled artisan will recognize the interchangeability of various features from different embodiments. The various features described, as well as other known equivalents for each feature, can be mixed and matched by one of ordinary skill in this art to construct additional systems and techniques in accordance with principles of this disclosure.