Patent Publication Number: US-2012032587-A1

Title: LED string light

Description:
BACKGROUND OF THE PRESENT INVENTION 
     1. Field of Invention 
     The present invention relates to a string light, and more particularly to a LED string light, wherein a plurality of diode units are spacedly and directly mounted on a conductive wire for generating 360° light emitted from the diode units, so as to minimize a diameter of the string light. 
     2. Description of Related Arts 
     The string light normally has a plurality of light bulbs mounted along an elongated wire, so as to electrically link to a power source for generating light for decoration or illumination purpose. It is also well known as a decoration light having a predetermined flexibility for generally conform a shape of an object being decorated or forming variety of shapes for lighting up the environment. For examples, placing the string light along the peripheral edges of the roof top of a house; or bending the string light to a predetermined shape for decorating the restaurant for commercial purposes. 
     In order to decorate the outer area, such as back yard, house, or commercial building, the string light may further comprises an outer cylindrical casing for receiving the string light therewithin, so that the string light may be able to use under the variety of weathers, such as raining. 
     The cylindrical casing usually made by a transparent material enclosed the wire and light bulbs therein, so that the light generated from the light bulb is able to emit through the transparent cylindrical casing. In order to maintain the characteristic of the string light, the cylindrical casing is made by the material having a predetermined flexibility, so that the string light with the cylindrical casing is able to be flexibly bended for decoration purpose while protecting the light bulb. The cylindrical casing can also prevent the wires of the string light tangled together after taking out the string light from a storage place, and prevent the light bulbs crushed with each other to cause the damage of the string light. 
     However, the light bulbs or LEDs mounted on the wires of the string light usually are more bulky, so that the diameter of the cylindrical casing requires a relatively larger size for accommodating the light bulbs or LEDs therewithin. Take the LED for example. Each of the LEDs comprises a diode sealably encased within a sealing enclosure, wherein two terminal ends are extended from the diode to electrically mount the LED at the wires to electrically link to a power source or control unit. 
     Therefore, the diameter of the cylindrical casing requires a relatively larger size for receiving the string light therewithin. The flexibility of the string light with the casing is reduced, so that the applications of the string light are limited. The string light can not be flexibly enough to conform the object and being bended to desired shape for decoration. The bulky string light also occupies a considerable storage space. It is difficult to fold or bend the string light with the bulky cylindrical casing to a compact size for storage. 
     Furthermore, the light generated from the diode, mounted at the wire through the two terminal ends of the diode, is limited to emit through the sealing enclosure, so that the light emitting angle is normally around 140° or less. Thus, the LEDs at the wires can not efficiently emit the light through the sealing enclosure and the cylindrical transparent casing. 
     SUMMARY OF THE PRESENT INVENTION 
     An object of the present invention is to provide a LED string light, wherein the diodes are directly and spacedly mounted at a conductive wire to generate a 360° light emitted from the diodes. 
     Another object of the present invention is to provide a LED string light, wherein the diode enclosure is sealably and directly encasing each of the diodes with the conductive wire to maintain the diode at the conductive wire in position, so as to minimize the size of each of diode units. 
     Another object of the present invention is to provide a LED string light, wherein the diameter of the tubular casing is less than 1.27 cm (½ inch), so as to increase the flexibility of the tubular casing of the string light. 
     Another object of the present invention is to provide a LED string light, wherein one or more circuit wires are electrically connected to the control unit to form a circuit among the conductive wire, circuit wires, and the control unit to control and operate the light source arrangement of the string light. 
     Another object of the present invention is to provide a LED string light, wherein each of the circuit wires is formed via a core circuit being covered by an insulation layer, which is made by a non conductive material, so as to prevent the circuit wires electrically contacting with the conductive wire. 
     Another object of the present invention is to provide a LED string light, wherein the circuit wire is an enameled wire. 
     Another object of the present invention is to provide a LED string light, wherein one or more adaptors are provided for electrically connecting to another string light, so as to selectively prolong the overall length of the string light. 
     Another object of the present invention is to provide a LED string light, wherein the adaptors comprises first and second attachments, which are embodied as a plug and a socket respectively, so that the adaptors enables the string light to detachably connect with one another, so as to selectively adjust the length of the string light. 
     Another object of the present invention is to provide a LED string light, wherein the diode units are connected in series manner via spacedly coupling along the conductive wire. 
     Accordingly, in order to accomplish the above objectives, the present invention provide a LED string light, which comprises an elongated tubular casing having an elongated light cavity therewith, a light source arrangement being received within the light cavity, and a control unit electrically linking to the light source for controlling and operating the light source arrangement, so as to provide an electricity thereto. 
     The light source arrangement further comprises at least one conductive wire, and a plurality of diode units spacedly and directly coupled along the conductive wire to generate a 360° light emitted from each of the diode units. 
     Each of the diode units comprises a diode, wherein the diode is sealably encased by a diode enclosure. The diode enclosure is directly encasing the diode with the conductive wire to maintain the diode at the conductive wire in position. 
     Therefore, the diameter of the tubular casing is reduced due to the reduced volume of each of diode units by directly forming at the conductive wire via the diode enclosure. Thus, the volume of the string light is minimized, so as to maximize the flexibility of the tubular casing for bending the string light. 
     Accordingly, the present invention also provides a method for manufacturing the LED string light, which comprises the steps of followings. 
     (a) spacedly bonding the diodes along a conductive wire for generating a 360° light emitted from the diodes; 
     (b) sealably encasing the diodes by the diode enclosures respectively to retain the diodes in position along the conductive wire, so as to form the diode units thereat; and 
     (c) receiving the conductive wire with the diode units bonded therealong within the light cavity of the outer tubular casing. 
     These and other objectives, features, and advantages of the present invention will become apparent from the following detailed description, the accompanying drawings, and the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a LED string light according to a preferred embodiment of the present invention. 
         FIG. 2  is a partial view of the LED string light according to the preferred embodiment of the present invention, illustrating a conductive wire and two circuit wires received within a light cavity of tubular casing. 
         FIG. 3  is a partially sectional view of the LED string light according to the preferred embodiment of the present invention. 
         FIG. 4  is a circuit diagram of the LED string light according to the preferred embodiment of the present invention. 
         FIG. 5  is a flow chart of a method for making LED string light according to the preferred embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIGS. 1 to 3 , a LED string light according to a preferred embodiment of the present invention is illustrated, wherein the string light comprises an elongated tubular casing  100  defining an elongated light cavity  102  therewithin, and a light source arrangement  200  being received within the light cavity  102  of the tubular casing  100 . 
     The tubular casing  100  is preferably made by a light transmissible material, so that a light generated from the light source arrangement  200  is able to emit the light through the light transmissible material of the tubular casing  100 . The material of the tubular casing  100  also has a predetermined flexibility, so that the string light is able to be folded or bended to conform to the shape of an object. 
     The light source arrangement  200  comprises at least one conductive wire  202  extended within the light cavity  102  of the tubular casing  100  and a plurality of diode units  204  spacedly and directly coupled along the conductive wire  202  for generating 360° light emitted from each of said diode units  204 . 
     The LED string light further comprises a control unit  300  electrically linking to the light source arrangement  200  for controlling and operating the light source arrangement  200 , so as to provide electricity thereto for generating the light. It is appreciated that the control unit  300  may has a switch for controllably switching the power in an on-and-off manner. A control circuit may be optionally provided for setting a time period for automatically controlling the string light. 
     According to the preferred embodiment, the control unit  300  comprises a transformer circuit  224  electrically linking with the light source arrangement  200  and an AC adapter  226  electrically extending from the transformer circuit  224  for electrically connecting with an AC power source. Therefore, the transformer circuit  224  can transform an AC current to a DC current to the light source arrangement  200 . It is appreciated that the control unit  300  can be a battery housing for receiving a replaceable battery therein so as to electrically connect to the light source arrangement  200 . 
     As mentioned above, the light source arrangement  200  further comprises at least one circuit wire  206  electrically linking to the control unit  300  to form a circuit among the conductive wire  202 , the diode unit  204 , the circuit wire  206 , and the control unit  300 , such that the control unit  300  generates a signal and electricity to control and operate the light source arrangement  200 , so as to controllably generate the light emitted from the diode unit  204 . 
     Accordingly, two circuit wires  206  are preferably provided in the present embodiment to form the circuit, wherein each of the circuit wires  206  comprises a core wire  208  and an insulation layer  210  having a tubular structure and encasing with the core circuit  208  therewithin to form the circuit wire  206 . The core wire  208  is preferably made by a conductive material for electrically linking to the control unit  300  and the conductive wire  202  to form the circuit. The insulation layer  210  is preferably made by a non conductive material, which has a much lower conductively that is insignificant to electrically transfer the electrical signals or electrons via contacting with the outer surface of the insulation layer  210  of the circuit wire  206 , such that the circuit wire  206  covered by the insulation layer  210  is able to prevent the circuit wires  206  electrically contacting with the conductive wire  202  within the light cavity  102 . 
     It is worth to mention that electrically contacting between the conductive wire  202  and circuit wire  206  may cause the shortage of the circuit, so that the diode units  204  of the light source arrangement  200  may not be able normally perform the operation to emit the light therefrom. The circuit wire  206  with the insulation layer  210  is able to efficiently and simply prevent the shortage of the circuit to stably perform the string light. The insulation layer  210  may also be provided to cover the outer surface of the conductive wire  202  only, or provided to cover both the conductive wire  202  and the core wire  206 . 
     According to the preferred embodiment, an enameled wire is preferably used as the circuit wire  206  to prevent the conductive wire  202  electrically contacting with the enameled wire, which normally has a coating insulation at the outer surface of the enameled wire, so as to prevent electrically contacting with the conductive wire  202 . 
     Each of the diode units  204  comprises a diode  212  directly and electrically fused at the conductive wire  202 , and a diode enclosure  214  sealably encasing the diode  212  at the conductive wire  202  to retain the diode  212  in position. In other words, the diode enclosure  214  is encasing the diode  212  and the conductive wire  202  to integrally and directly form the diode unit  204  at the conductive wire  202 . 
     Accordingly, the diodes  212  can be embodied with different properties that each of the diodes  212  can generate a particular light effect. Therefore, when the light source arrangement  200  is activated, the diodes  212  can generate different light effects, such as different colors. 
     The diode units  204  coupled at the conductive wire  202  is preferably connected in series in each of the string light, so that a constant current is passing through each of the diode units  204  along the same conductive wire  202 . 
     In the preferred embodiment, the diode enclosure  214  is preferably made by resin, which is a viscous liquid having the adhesives properties being able to retain the diodes  212  at the conductive wire  202  at a predetermined position, and solidified after dried at room temperature to provide the retaining force to couple the diodes  212  with the conductive wire  202 . After the resin became solid to sealably encasing the diodes  212 , the solidified resin of the diode enclosure  214  becomes half transparent for allowing the light generated from the diode  212  to emit through the light transmissible solidified resin of the diode enclosure  214 . 
     It is appreciated that the diode enclosure  214  is not limited to be made by resin. The diode enclosure  214  may be made by other materials which is able to sealably encasing the diodes  212  and retain it in position, while having the light transmissible properties when the material is turned to the solid state to retain the diode  212  at the conductive wire  202 . 
     Accordingly, the Led light string further comprises at least an adaptor  216  for detachably and electrically coupling the light source arrangement  200  with the control unit  300 . Preferably, two adaptors  216  are provided at two opposed ends of the elongated tubular casing  100  for electrically linking the light source arrangement  200 . One of the adapters  216  is arranged to detachably and electrically couple with the control unit  300  so as to form the completed circuit for operating the light source arrangement  200 . The other adapter  216  is arranged to detachably and electrically couple with another light source arrangement  200  via the adapter  216  thereof to prolong the length of the Led string light. 
     In the preferred embodiment, the two adaptors  216  preferably are a first attachment  218  and a second attachment  220 . The first attachment  218  is provided at one end of the tubular casing  100  for electrically and detachably connecting the light source arrangement  200  to the control unit  300 . The second attachment  220  is provided at an opposite end of the tubular casing  100  to form the completed circuit, so as for connecting to another string light via the second attachment  220 , such that the first and second attachment  218 ,  220  are formed the completed circuit by electrically connecting the light source arrangement  200  with the control unit  300 , so as to supply the electricity to the diode units  204 . 
     In the preferred embodiment, the first attachment  218  is exemplary embodied as a plug and the second attachment  220  is exemplary embodied as a socket provided at the opposite end of the tubular casing  200 . The socket of the second attachment  220  is further preferably provided at the control unit  300 , so that the plug of the first attachment  218  is able to insert into the socket of the second attachment  220  at the control unit  300 , so as to electrically and detachably connect the light source arrangement  200  to the control unit  300 . The socket at the opposite end of the tubular casing  100  is able to electrically connect with another plug of another string light to prolong the LED string light to the predetermined length via the adaptors  216 . 
     It is worth to mention that when two or more light source arrangements  200  are electrically connected via the adapters  216 , the light source arrangements  200  are preferably connected in a parallel electrical connection while the diodes  212  of each of the light source arrangements  200  are electrically connected along the respective conductive wire  202  in a series electrical connection. As shown in  FIG. 4  as an example of the present invention, there are totally two light source arrangements  220  being connected in parallel electrical connection to the control unit  300 , wherein each of the light source arrangements  220  has forty-six diode units  204  and two resistors  22  connected along the conductive wire  202  in a series electrical connection. 
     In order to securely and electrically coupling the first and second attachment  218 ,  220 , a cap  221  having an inner threaded portion provided at the first attachment  218  may further provided for rotatably and detachably engaging with an outer threaded portion of the second attachment  220 , such that after the plug and socket of first and second attachment  218 ,  220  are detachably coupled with each other, the cap  221  is able to rotatably secure the first attachment  218  with the second attachment  220 . 
     It is appreciated that the first and second attachments  218 ,  220  of the adaptors  216  are interchangeable. The adaptor  216  may only comprises the first attachment  218  or the second attachment  220  formed at one end of the tubular casing  100  for electrically connecting to the control unit  300 . 
     As mentioned above, the size of each of the diode units  204  is minimized due to the diode  212  is directly coupled at the conductive wire  202  and being integrally encased via the diode enclosure  214  to directly seal the diode  212  and the partial conductive wire  202  to form the diode unit  204 , so as to generate the 360° light. 
     Therefore, the diameter of the tubular casing  100  is able to be reduced, wherein the diameter of the tubular casing  100  of the present invention is able to be less than 1/2″, preferably 1/8″, so as to minimize the volume of the string light and enhance the flexibility of the elongated tubular casing  100  of the string light. 
     The string light of the present invention not only increases the flexibility and minimizes the size of the tubular casing  100 , but also efficiently enhances the light intensity by generating the 360° light. It can be easily bended to conform to a shape of an object for decoration or decoratively lighten up the environment. 
     The minimized diameter of the tubular casing  100  has a size for conveniently applying in variety of areas and objects, while given a predetermined strength to support the light source arrangement  200 . The relatively smaller diameter of the tubular casing  100 , which is able to prevent the conductive wire  202  with the diode units  204  and the circuit wires  206  tangling together, also minimizes the space for storing the LED string light. 
     As described above, one or more resistors  222  may further provided to electrically linking to the light source arrangement  200  for adjusting the currently and/or voltage of string light. The resistors  222  are preferably connected with the diode units  204  in series manner to balance the circuit of the string light. 
     Referring to  FIG. 5  of the drawings, a method of making LED string light is also provided, wherein the method comprises the steps of followings. 
     (a) Spacedly and directly bond the diodes  212  along the conductive wire  202  for generating a 360° light emitted from the diodes  212 . 
     (b) Sealably encase each of the diodes  212  by the diode enclosure  214  to retain the diode  212  in position along the conductive wire  202 , so as to form the diode units  214  thereat formed by each of the diodes  212  encased by each of the diode enclosure  214 . Therefore, the diode enclosure  214  is integrally formed with the diodes  212  and the partial conductive wire  202  to emit the 360° light therefrom. 
     (c) Receive the conductive wire  202  with the diode units  204  bonded therealong within the light cavity  102  of the outer tubular casing  100 . 
     One skilled in the art will understand that the embodiment of the present invention as shown in the drawings and described above is exemplary only and not intended to be limiting. 
     It will thus be seen that the objects of the present invention have been fully and effectively accomplished. The embodiments have been shown and described for the purposes of illustrating the functional and structural principles of the present invention and is subject to change without departure from such principles. Therefore, this invention includes all modifications encompassed within the spirit and scope of the following claims.