Patent Publication Number: US-10330302-B2

Title: Gas-free light bulb device

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a light bulb device, and more particularly to a gas-free light bulb device that has filaments heat-dissipating through a glass bulb, the glass bulb has a sufficient large surface area such that the heat convection effect of the glass bulb with ambient air is excellent. With assistance of a heatsink, the heat dissipation efficiency of the glass bulb allows the gas-free light bulb device to be fabricated without gas filling and aluminum elements. Therefore, the gas-free light bulb device has a lower manufacturing cost when compared to conventional gas-free light bulb devices in the market. 
     2. Description of Related Art 
     Conventional tungsten light bulb devices has undesirable high temperature-rising rate due to low manufacturing cost. When the tungsten filaments inside the light bulb devices is heated under an incandescent status with high temperate the tungsten filaments vaporizes excessively fast and a lifespan thereof is greatly lowered. Furthermore, the vaporized tungsten is deposited and accumulated on an inner surface of the bulb and darkens the bulb, which negatively affects the illumination of the operating light bulb device. As a result, the lifespan of the light bulb device is decreased or failure rate of the light bulb device is undesirably high. 
     Conventional gas-filled light bulb devices are also be sold in the market and bulbs thereof are filled with inert gas, which excellently decreases the vaporization rate of its tungsten filaments in the inert gas environment when compared to the vacuum environment. In other words, under the same lifespan condition, operating temperature the tungsten filaments of such gas-filled light bulb device may be higher than the operating temperature of the vacuum environment. Therefore, after vacuumed, the bulb of gas-filled light bulb device is filled with argon gas, nitrogen gas or mixture thereof with a specific pressure. 
     Although the aforementioned gas-filled light bulb device is able to excellently solve the issues of high temperature rising rate or overheated problems, such gas-filled light bulb device has higher manufacturing cost and is therefore more expensive. 
     Conventional gas-free light bulb device has been developed to replace conventional tungsten filaments with filament-shaped light emitting diode (LED) modules. Because LEDs generates considerable heat, aluminum heatsinks are primarily employed to assist heat dissipation, which results in increase of manufacturing cost of the gas-free light bulb device. Therefore the gas-free light bulb device would not prevail over the aforementioned gas-filled light bulb device in cost. 
     To overcome the shortcomings, the present invention provides a gas-free light bulb device to mitigate or obviate the aforementioned problems. 
     SUMMARY OF THE INVENTION 
     The main objective of the invention is to provide a gas-free light bulb device that has filaments heat-dissipating through a glass bulb, the glass bulb has a sufficient large surface area such that the heat convection effect of the glass bulb with ambient air is excellent. With assistance of a heatsink, the heat dissipation efficiency of the glass bulb allows the gas-free light bulb device to be fabricated without gas filling and aluminum elements. Therefore, the gas-free light bulb device has a lower manufacturing cost when compared to conventional gas-free light bulb devices in the market. 
     A gas-free light bulb device in accordance with the present invention comprises: a lamp head; 
     a heatsink mounted on the lamp head and having a mounting slot defined in the heatsink; and a driver circuit board mounted in the mounting slot; a bulb mounted on the heatsink and having a cavity defined in the bulb; a glass core column mounted in the mounting slot of the heatsink and extending in the cavity of the bulb; multiple filament assemblies suspended on the glass core column and indirectly electrically connected to the driver circuit board; and a resilient extending element mounted on the glass core column and having a resilient rubber sleeve mounted around the glass core column, wherein a thermal expansion coefficient of the resilient rubber sleeve is higher than a thermal expansion coefficient of the glass core column; and multiple resilient extending rubber bars formed on and protruding radially outward from the resilient rubber sleeve and corresponding to the multiple filament assemblies, and an outer end of each resilient extending rubber bar connected to a corresponding filament assembly. When the gas-free light bulb device is not operated under room temperature, an inner diameter of the resilient rubber sleeve is not larger than an outer diameter of the glass core column such that the resilient rubber sleeve is mounted tightly on a lower position of the glass core column and is unable to slide, at the meantime, the resilient extending rubber bars are curved and apply resilient force to the filament assemblies and the resilient rubber sleeve. When the gas-free light bulb device is operated with rising temperature, the resilient rubber sleeve is heated and expanded to make the inner diameter larger than the outer diameter of the glass core column, at the meantime, the resilient rubber sleeve is loosened relative to the glass core column, and resilient force of the resilient extending rubber bar drives the resilient rubber sleeve to slide upward along the glass core column to an upper position of the glass core column and to pivot the multiple filament assemblies upward relative to the glass core column until the bottom end of each filament assembly contacts the bulb an inner wall of the cavity and conducts heat of each filament assembly to the bulb. 
     Another gas-free light bulb device in accordance with the present invention comprises: a lamp head; a heatsink mounted on the lamp head and having a mounting slot defined in the heatsink; and a driver circuit board mounted in the mounting slot; a bulb mounted on the heatsink and having a cavity defined in the bulb; a glass core column mounted in the mounting slot of the heatsink and extending in the cavity of the bulb; multiple filament assemblies suspended on the glass core column and indirectly electrically connected to the driver circuit board; and a resilient extending element mounted on the glass core column and having a resilient rubber sleeve mounted around the glass core column, wherein a thermal expansion coefficient of the resilient rubber sleeve is higher than a thermal expansion coefficient of the glass core column; and multiple resilient extending rubber bars formed on and protruding radially outward from the resilient rubber sleeve and corresponding to the multiple filament assemblies, and an outer end of each resilient extending rubber bar connected to a corresponding filament assembly; wherein, when the gas-free light bulb device is not operated under room temperature, an inner diameter of the resilient rubber sleeve is not larger than an outer diameter of the glass core column such that the resilient rubber sleeve is mounted tightly on a lower position of the glass core column and is unable to slide, at the meantime, the resilient extending rubber bars are curved and apply resilient force to the filament assemblies and the resilient rubber sleeve. 
     Still another gas-free light bulb device in accordance with the present invention comprises: a lamp head; a heatsink mounted on the lamp head and having a mounting slot defined in the heatsink; and a driver circuit board mounted in the mounting slot; a bulb mounted on the heatsink and having a cavity defined in the bulb; a glass core column mounted in the mounting slot of the heatsink and extending in the cavity of the bulb; multiple filament assemblies suspended on the glass core column and indirectly electrically connected to the driver circuit board; and a resilient extending element mounted on the glass core column and having a resilient rubber sleeve mounted around the glass core column, wherein a thermal expansion coefficient of the resilient rubber sleeve is higher than a thermal expansion coefficient of the glass core column; and multiple resilient extending rubber bars formed on and protruding radially outward from the resilient rubber sleeve and corresponding to the multiple filament assemblies, and an outer end of each resilient extending rubber bar connected to a corresponding filament assembly; wherein, when the gas-free light bulb device is operated with rising temperature, the resilient rubber sleeve is heated and expanded to make an inner diameter of the resilient rubber sleeve larger than an outer diameter of the glass core column, at the meantime, the resilient rubber sleeve is loosened relative to the glass core column, and resilient force of the resilient extending rubber bar drives the resilient rubber sleeve to slide upward along the glass core column to an upper position of the glass core column and to pivot the multiple filament assemblies upward relative to the glass core column until the bottom end of each filament assembly contacts the bulb an inner wall of the cavity and conducts heat of each filament assembly to the bulb. 
     The present invention comprises the following advantages. 
     1. The gas-free light bulb device of the present invention employs the filament-shaped LED modules instead of tungsten filaments that will vaporize. Therefore, no need of filling inert gas in to the bulb, which decreases the manufacturing cost of the gas-free light bulb device. 
     2. After the gas-free light bulb device is operated and heated, through contact between of the multiple filament assemblies and the inner wall of the cavity of the bulb, the heat of the multiple filament assemblies is conducted to the bulb. A further thermal exchange is between the bulb and ambient air would bring the heat from the bulb. Therefore, the gas-free light bulb device of the present invention has better heat dissipation function and longer lifespan when compared to conventional light bulbs. 
     3. The resilient extending element only provides resilient force by rubber material without any mechanically connected components such that mechanic wearing and failure are obviated. 
     Other objectives, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a first embodiment of a gas-free light bulb device in accordance with the present invention; 
         FIG. 2  is an exploded perspective view of the gas-free light bulb device in  FIG. 1 ; 
         FIG. 3  is a perspective view of the gas-free light bulb device in  FIG. 1  omitting a bulb; 
         FIG. 4  is a front view of the gas-free light bulb device in  FIG. 1 ; 
         FIG. 5  is a cross sectional front view of the gas-free light bulb device along line A-A in  FIG. 4 ; 
         FIG. 6  is a cross sectional view of the gas-free light bulb device in  FIG. 1  not operated in a lower temperature; 
         FIG. 7  is an operational cross sectional front view of the gas-free light bulb device in  FIG. 7  operated with a raised temperature; 
         FIG. 8  is a cross sectional front view of a second embodiment of the gas-free light bulb device in accordance with the present invention; 
         FIG. 9  is a cross sectional front view of a third embodiment of the gas-free light bulb device in accordance with the present invention; and 
         FIG. 10  is a cross sectional front view of a fourth embodiment of the gas-free light bulb device in accordance with the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     With reference to  FIGS. 1 to 3 , a first embodiment of a gas-free light bulb device in accordance with present invention comprises a lamp head  10 , heatsink  20 , a bulb  30 , a glass core column  40 , multiple filament assemblies  50 , and a resilient extending element. 
     The lamp head  10  may be connected to an indoor bulb socket. Furthermore, the lamp head  10  mad be made of metal. Preferably, the lamp head may be made of aluminum or copper. 
     The heatsink  20  is mounted on the lamp head  10  and has a mounting slot  200  and a driver circuit board  25 . The mounting slot  200  is defined in the heatsink  20 . The driver circuit board  25  is mounted in the mounting slot  200 . 
     The bulb  30  is mounted on the heatsink  20  and has a cavity  300 . The cavity  300  is defined in the bulb  30 . Furthermore, the heatsink  20  may be made of metal. Preferably, the heatsink  20  may be made of metal such as steel, aluminum or copper and may be made of plastic. 
     With further reference to  FIGS. 4 and 5 , the glass core column  40  is mounted in the mounting slot  200  of the heatsink  20 , extends in the cavity  300  of the bulb  30 , is electrically connected to the driver circuit board  25  and has multiple wire sets mounted on the glass core column  40 . Each wire set has an upper core wire  41  and a lower core wire  42 . The upper core wire  41  is mounted on a top end of the glass core column  40 . The lower core wire  42  is mounted on a bottom end of the glass core column  40 . 
     The multiple filament assemblies  50  are suspended on the glass core column  40 , is electrically connected to the glass core column  40  and is indirectly electrically connected to the driver circuit board  25 . Preferably, the multiple filament assemblies  50  correspond to and are connected respectively to the wire sets of the glass core column  40 . A top end of each filament assembly  50  is connected to the upper core wire  41  of a corresponding wire set. A bottom end of each filament assembly  50  is connected to the lower core wire  42  of the corresponding wire set. Furthermore, each filament assembly  50  may be a filament-shaped LED module and has at least one LED. 
     The resilient extending element  60  is mounted on the glass core column  40  and has a resilient rubber sleeve  61  and multiple resilient extending rubber bars  62 . The resilient rubber sleeve  61  is mounted around the glass core column  40 , and a thermal expansion coefficient of the resilient rubber sleeve  61  is higher than a thermal expansion coefficient of the glass core column  40 . The multiple resilient extending rubber bars  62  are formed on and protrude radially outward from the resilient rubber sleeve  61  and correspond to the multiple filament assemblies  50 . An outer end of each resilient extending rubber bar  62  is connected to a corresponding filament assembly  50 . 
     With further reference to  FIG. 6 , when the gas-free light bulb device is not operated under room temperature, an inner diameter of the resilient rubber sleeve  61  is not larger than an outer diameter of the glass core column  40  such that the resilient rubber sleeve  61  is mounted tightly on a lower position of the glass core column  40  and is unable to slide. At the meantime, the resilient extending rubber bars  62  are curved and apply resilient force to the filament assemblies  50  and the resilient rubber sleeve  61 . 
     With further reference to  FIG. 7 , when the gas-free light bulb device is operated with rising temperature, the resilient rubber sleeve  61  is heated and expanded to make the inner diameter larger than the outer diameter of the glass core column  40 . At the meantime, the resilient rubber sleeve  61  is loosened relative to the glass core column  40 , and resilient force of the resilient extending rubber bar  62  drives the resilient rubber sleeve  61  to slide upward along the glass core column  40  to an upper position of the glass core column  40  and to pivot the multiple filament assemblies  50  upward relative to the glass core column  40  until the bottom end of each filament assembly  50  contacts the bulb  30  an inner wall  301  of the cavity  300  and conducts heat of each filament assembly  50  to the bulb  30 . 
     With further reference to  FIG. 8 , a second embodiment of the gas-free light bulb device in accordance with the present invention is similar to the first embodiment and comprises: a lamp head  10 , a heatsink a  20 , a bulb  30 , a glass core column  40 , multiple filament assemblies  50  and a resilient extending element  60 . The lamp head  10  may be connected to an indoor bulb socket. Furthermore, the lamp head  10  may be made of metal. Preferably, the lamp head may be made of aluminum or copper. The heatsink  20  is mounted on the lamp head  10  and has a mounting slot  200  and a driver circuit board  25 . The mounting slot  200  is defined in the heatsink  20 . The driver circuit board  25  is mounted in the mounting slot  200 . The bulb  30  is mounted on the heatsink  20  and has a cavity  300 . The cavity  300  is defined in the bulb  30 . Furthermore, the heatsink  20  may be made of metal. Preferably, the heatsink  20  may be made of steel, aluminum or copper. The glass core column  40  is mounted in the mounting slot  200  of the heatsink  20 , extends in the cavity  300  of the bulb  30 , is electrically connected to the driver circuit board  25  and has multiple wire sets mounted on the glass core column  40 . Each wire set has an upper core wire  41  and a lower core wire  42 . The upper core wire  41  is mounted on a top end of the glass core column  40 . The lower core wire  42  is mounted on a bottom end of the glass core column  40 . The multiple filament assemblies  50  are suspended on the glass core column  40 , is electrically connected to the glass core column  40  and is indirectly electrically connected to the driver circuit board  25 . Preferably, the multiple filament assemblies  50  correspond to and are connected respectively to the wire sets of the glass core column  40 . A top end of each filament assembly  50  is connected to the upper core wire  41  of a corresponding wire set. A bottom end of each filament assembly  50  is connected to the lower core wire  42  of the corresponding wire set. Furthermore, each filament assembly  50  may be a filament-shaped LED module and has at least one LED. The resilient extending element  60  is mounted on the glass core column  40  and has a resilient rubber sleeve  61  and multiple resilient extending rubber bars  62   a . The resilient rubber sleeve  61  is mounted around the glass core column  40 , and a thermal expansion coefficient of the resilient rubber sleeve  61  is higher than that of the glass core column  40 . The multiple resilient extending rubber bars  62   a  protrude radially from the resilient rubber sleeve  61  and correspond to the multiple filament assemblies  50 . An outer end of each resilient extending rubber bar  62   a  is connected to a corresponding filament assembly  50 . 
     The difference of the second embodiment is that each resilient extending rubber bar  62   a  has multiple wave-shaped resilient portions formed on the resilient extending rubber bar  62   a  and connected to one another. The wave-shaped resilient portions selectively compress or stretch. 
     With further reference to  FIG. 9 , a third embodiment of the gas-free light bulb device in accordance with the present invention is similar to the first embodiment and comprises: a lamp head  10 , a heatsink a  20 , a bulb  30 , a glass core column  40 , multiple filament assemblies  50  and a resilient extending element  60 . The lamp head  10  may be connected to an indoor bulb socket. Furthermore, the lamp head  10  mad be made of metal. Preferably, the lamp head may be made of aluminum or copper. The heatsink  20  is mounted on the lamp head  10  and has a mounting slot  200  and a driver circuit board  25 . The mounting slot  200  is defined in the heatsink  20 . The driver circuit board  25  is mounted in the mounting slot  200 . The bulb  30  is mounted on the heatsink  20  and has a cavity  300 . The cavity  300  is defined in the bulb  30 . Furthermore, the heatsink  20  may be made of metal. Preferably, the heatsink  20  may be made of steel, aluminum or copper. The glass core column  40  is mounted in the mounting slot  200  of the heatsink  20 , extends in the cavity  300  of the bulb  30 , is electrically connected to the driver circuit board  25  and has multiple wire sets mounted on the glass core column  40 . Each wire set has an upper core wire  41  and a lower core wire  42 . The upper core wire  41  is mounted on a top end of the glass core column  40 . The lower core wire  42  is mounted on a bottom end of the glass core column  40 . The multiple filament assemblies  50  are suspended on the glass core column  40 , is electrically connected to the glass core column  40  and is indirectly electrically connected to the driver circuit board  25 . Preferably, the multiple filament assemblies  50  correspond to and are connected respectively to the wire sets of the glass core column  40 . A top end of each filament assembly  50  is connected to the upper core wire  41  of a corresponding wire set. A bottom end of each filament assembly  50  is connected to the lower core wire  42  of the corresponding wire set. Furthermore, each filament assembly  50  may be a filament-shaped LED module and has at least one LED. The resilient extending element  60  is mounted on the glass core column  40  and has a resilient rubber sleeve  61  and multiple resilient extending rubber bars  62   b . The resilient rubber sleeve  61  is mounted around the glass core column  40 , and a thermal expansion coefficient of the resilient rubber sleeve  61  is higher than that of the glass core column  40 . The multiple resilient extending rubber bars  62   b  protrude radially from the resilient rubber sleeve  61  and correspond to the multiple filament assemblies  50 . An outer end of each resilient extending rubber bar  62   b  is connected to a corresponding filament assembly  50 . 
     The difference of the third embodiment is that each resilient extending rubber bar  62   b  has multiple Z-shaped resilient portions formed on the resilient extending rubber bar  62   b  and connected to one another. The Z-shaped resilient portions selectively compress or stretch. 
     With further reference to  FIG. 10 , a fourth embodiment of the gas-free light bulb device in accordance with the present invention is similar to the first embodiment and comprises: a lamp head  10 , a heatsink a  20 , a bulb  30 , a glass core column  40 , multiple filament assemblies  50  and a resilient extending element  60 . The lamp head  10  may be connected to an indoor bulb socket. Furthermore, the lamp head  10  mad be made of metal. Preferably, the lamp head may be made of aluminum or copper. The heatsink  20  is mounted on the lamp head  10  and has a mounting slot  200  and a driver circuit board  25 . The mounting slot  200  is defined in the heatsink  20 . The driver circuit board  25  is mounted in the mounting slot  200 . The bulb  30  is mounted on the heatsink  20  and has a cavity  300 . The cavity  300  is defined in the bulb  30 . Furthermore, the heatsink  20  may be made of metal. Preferably, the heatsink  20  may be made of steel, aluminum or copper. The glass core column  40  is mounted in the mounting slot  200  of the heatsink  20 , extends in the cavity  300  of the bulb  30 , is electrically connected to the driver circuit board  25  and has multiple wire sets mounted on the glass core column  40 . Each wire set has an upper core wire  41  and a lower core wire  42 . The upper core wire  41  is mounted on a top end of the glass core column  40 . The lower core wire  42  is mounted on a bottom end of the glass core column  40 . The multiple filament assemblies  50  are suspended on the glass core column  40 , is electrically connected to the glass core column  40  and is indirectly electrically connected to the driver circuit board  25 . Preferably, the multiple filament assemblies  50  correspond to and are connected respectively to the wire sets of the glass core column  40 . A top end of each filament assembly  50  is connected to the upper core wire  41  of a corresponding wire set. A bottom end of each filament assembly  50  is connected to the lower core wire  42  of the corresponding wire set. Furthermore, each filament assembly  50  may be a filament-shaped LED module and has at least one LED. The resilient extending element  60  is mounted on the glass core column  40  and has a resilient rubber sleeve  61  and multiple resilient extending rubber bars  62   c . The resilient rubber sleeve  61  is mounted around the glass core column  40 , and a thermal expansion coefficient of the resilient rubber sleeve  61  is higher than that of the glass core column  40 . The multiple resilient extending rubber bars  62   c  protrude radially from the resilient rubber sleeve  61  and correspond to the multiple filament assemblies  50 . An outer end of each resilient extending rubber bar  62   c  is connected to a corresponding filament assembly  50 . 
     The difference of the fourth embodiment is that each resilient extending rubber bar  62   c  has a spiral resilient portion formed on the resilient extending rubber bar  62   c . The spiral resilient portion selectively compresses or stretches. 
     By the aforementioned features, the resilient extending element  60  connected to the multiple filament assemblies  50  of the gas-free light bulb device is capable of controlling the filament assemblies  50  to contact the inner wall of the bulb  30 . When gas-free light bulb device is non-operated under the room temperature, the resilient rubber sleeve  61  is mounted tightly around the glass core column  40 . A friction between the resilient rubber sleeve  61  and the glass core column  40  is larger than the resilient force of the multiple resilient extending rubber bars  62  such that the multiple filament assemblies  50  would not contact the inner wall  301  of the cavity  300  of the bulb  30  in advance. When the gas-free light bulb device is installed to a bulb socket and operated to raise the temperature thereof over a specific value, the resilient rubber sleeve  61  with a higher thermal expansion coefficient is loosened relative to the glass core column  40 . The tightened and curved resilient extending rubber bars  62  drive the resilient rubber sleeve  61  to slide upward and simultaneously extend all of the filament assemblies  50  such that the bottom ends of the filament assemblies contact the inner wall  301  of the cavity  300  of the bulb  30  cavity  300 . 
     The present invention comprises the following advantages. 
     1. The gas-free light bulb device of the present invention employs the filament-shaped LED modules instead of tungsten filaments that will vaporize. Therefore, no need of filling inert gas in to the bulb, which decreases the manufacturing cost of the gas-free light bulb device. 
     2. After the gas-free light bulb device is operated and heated, through contact between of the multiple filament assemblies  50  and the inner wall  301  of the cavity  300  of the bulb  30 , the heat of the multiple filament assemblies  50  is conducted to the bulb  30 . A further thermal exchange is between the bulb  30  and ambient air would bring the heat from the bulb  30 . Therefore, the gas-free light bulb device of the present invention has better heat dissipation function and longer lifespan when compared to conventional light bulbs. 
     3. The resilient extending element  60  only provides resilient force by rubber material without any mechanically connected components such that mechanic wearing and failure are obviated. 
     4. Wave-shaped resilient portions, Z-shaped resilient portions and spiral resilient portions further improve the resilient force of the resilient extending rubber bar  62 , which ensures that the bottom ends of filament assemblies  50  contact the inner wall  301  of the cavity  300  of the bulb  30 . 
     Even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only. Changes may be made in the details, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.