Patent Publication Number: US-11391422-B2

Title: Light string package structure

Description:
RELATED APPLICATIONS 
     The present application is a continuation of U.S. patent application Ser. No. 16/751,064, filed Jan. 23, 2020, which claims priority to Chinese Patent Application No. 201910924211.7, filed on Sep. 27, 2019, all of which are incorporated herein by reference in their entireties. 
    
    
     FIELD OF THE INVENTION 
     This disclosure relates to a light string, and more particularly relates to a light string package structure. 
     BACKGROUND 
     A known light string is a configuration wherein a plurality of light sources are directly soldered on a wire in a spaced manner to form a string-shaped illumination device without a lamp holder in the art. For small light sources, such as bulbs and light emitting diodes (LEDs), it is a frequently used configuration. The light string may be easily configured into any form due to the maintenance of an original winding characteristic of the wire, so as to be suitable for special lighting needs or decorations. 
     In the art, the LED is directly soldered onto a wire after an insulating layer of the wire is directly removed. The electrode of the light emitting diode is directly soldered on an exposed metal core, and then solder joints are subjected to an insulating process. In the case where a light-transmitting cap is provided, the light-transmitting cap is fixed on a light source in an adhering manner. When the light string is bent considerably, a soldered portion will be also bent sharply. However, the solder usually lacks flexible or bendable properties, so that when the wire is bent significantly, the soldering joint easily fails, which makes the LED fail to emit light. 
     SUMMARY 
     In view of the above problem, this disclosure provides a light string package structure, so as to solve problems in the prior art. 
     This disclosure provides a light string package structure, including a light-transmitting cap, a wire, a light emitting diode and a transparent encapsulating or adhering substance such as an adhesive, epoxy or glue. In an embodiment, the light-transmitting cap includes a body, two guide pieces and two lugs. The interior of the body is hollow, and an opening is formed in the bottom surface of the body to communicate with the interior of the body. The two guide pieces are in parallel and protrude from the bottom of the body. A guide trench is defined between the two guide pieces, and the opening is located between the two guide pieces. The wire has a soldering section with an exposed metal core. The two lugs inversely extend outward from the edge of the bottom of the body, and correspond to two ends of the guide trench. The light emitting diode has a light emitting surface and a soldering surface. The soldering surface is soldered onto the soldering section, and the soldering section is flatly attached to the soldering surface. The transparent glue covers the soldering section to adhere the soldering section to the guide trench and the two lugs, and extends around to wrap the light emitting surface of the light emitting diode. The light-transmitting cap covers the light emitting diode, so that the light emitting diode is located at the opening, and the light emitting surface faces the interior of the body. The soldering section is located between the two guide pieces, and the transparent glue attaches the light emitting diode to the light-transmitting cap. 
     In one or more embodiments, other portions of the wire are covered by an insulating layer. 
     In one or more embodiments, the insulating layer is a plastic layer or insulating paint coating layer. 
     In one or more embodiments, a distance between two ends of the two lugs is equal to or greater than a length of the soldering section. 
     In one or more embodiments, the transparent glue attaches the soldering section to the two guide pieces and the edge of the opening. 
     In one or more embodiments, the transparent glue is an ultraviolet-curable adhesive. 
     By adopting the light string package structure, in addition to providing an optical effect through the light-transmitting cap, the fixing of the soldering section can be reinforced, thereby avoiding a soldering failure of the light emitting diode due to excessive bending of the soldering section in a use process of a light string. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a three-dimensional exploded diagram of an embodiment of this disclosure; 
         FIG. 2  is a three-dimensional diagram of an embodiment of this disclosure; 
         FIG. 3  is a cross-sectional schematic diagram of an embodiment of this disclosure; 
         FIG. 4  is a three-dimensional exploded diagram of another embodiment of this disclosure; 
         FIG. 5  is a three-dimensional diagram of another embodiment of this disclosure; 
         FIG. 6  and  FIG. 7  are cross-sectional schematic diagrams of an embodiment of this disclosure, illustrating a processing method of a light string package structure; 
         FIG. 8  and  FIG. 9  are three-dimensional diagrams of different application cases of this disclosure; 
         FIG. 10  is a cross-sectional exploded diagram of different application cases of this disclosure; and 
         FIG. 11  to  FIG. 13  are cross-sectional exploded diagrams of different application cases of this disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 ,  FIG. 2  and  FIG. 3 , a light string package assembly or lighting structure  100  disclosed by an embodiment of this disclosure is illustrated, and is used as one portion of a light string. The light string package structure  100  includes a light-transmitting cap  110 , one or more wires  120 , a light emitting diode  130  (LED  130 ) and a transparent adhesive  140 . 
     As shown in  FIG. 1 ,  FIG. 2  and  FIG. 3 , the light-transmitting cap  110  is made of a light-transmitting material that may be transparent and colorless, or may be in any color to provide illuminating light in different colors. The light-transmitting cap  110  includes a body  112  and two guide pieces  114 . The top of the body  112  may be in a lens form, and is used for refracting light to form a light condensation or scattering effect. The interior of the body  112  is hollow, and an opening  112   a  is formed in the bottom surface of the body  112  to communicate with the interior of the body  112 . 
     As shown in  FIG. 1 ,  FIG. 2  and  FIG. 3 , the number of wires  120  may be in any quantity, and the quantity is determined according to an electric connection mode of the LED  130 . In case of a series circuit, there may be only one wire  120 , and two ends of the wire  120  are respectively connected to a power source and the ground. In case of a parallel circuit, there may be two wires  120 : a power wire for supplying power and a ground wire. However, other electrical connection modes are not excluded. For example, when a programmable-controlled LED  130  is used, there will be a third wire  120  serving as a transmission line of a control signal.  FIG. 1 ,  FIG. 2  and  FIG. 3  depict a 3-wire embodiment. 
     As shown in  FIG. 1 ,  FIG. 2  and  FIG. 3 , each wire  120  includes a conductor portion  121  and an insulating layer  123 . Each conductor portion of each wire  120  has a soldering section  122  with an exposed metal core or conductor portion, and other conductor portions that are wrapped by the insulating layer such as a plastic layer or insulating paint-coating layer. That is, the wire  120  may be a plastic-covered wire, e.g., PVC-covered wire, or an enameled wire. When there are two or more wires  120  and the wires  120  are plastic-covered wires, the plurality of wires  120  may be connected side by side (parallel) via the plastic insulating layers to form a single wire assembly  120 . 
     As shown in  FIG. 1 ,  FIG. 2  and  FIG. 3 , the LED  130  has a light emitting surface  132  and a soldering surface  134 . A soldering pad is arranged on the soldering surface  134 , and is used for soldering the LED  130  onto the soldering sections  122  of the wires  120 , and the soldering surface  134  faces the wires  120 . 
     As shown in  FIG. 1 ,  FIG. 2  and  FIG. 3 , a guide trench  114   a  is defined between the two guide pieces  114 . The transparent adhesive  140  encapsulates or wraps around the soldering sections  122  of the wires  120  to affix the soldering sections  122  to the guide trench  114   a  and two lugs or flanges  116  of the light-transmitting cap  110 , and extends to wrap around the light emitting surface  132  of the LED  130 . The light-transmitting cap  110  covers the LED  130 , so that the LED  130  is located at the opening  112   a , and the light emitting surface  132  faces the interior of the body  112 . Meanwhile, the transparent adhesive  140  attaches the LED  130  and the soldering sections  122  to the light-transmitting cap  110 , so as to fix the light-transmitting cap  110  to the wires  120 . 
     As shown in  FIG. 1 ,  FIG. 2  and  FIG. 3 , the two guide pieces  114  of the light-transmitting cap  110  are arranged in parallel and protrude from the bottom of the body  112 , and the guide trench  114   a  is defined between the two guide pieces  114 . The opening  112   a  is located between the two guide pieces  114 , that is, the opening  112   a  is located in the guide trench  114   a . The body  112  further includes a flange that includes two lugs  116  that inversely extend outward from the edge of the bottom of the body  112 , and the two lugs  116  correspond to two ends of the guide trench  114   a . In an embodiment, a distance between two ends of the two lugs  116  must be equal to or greater than a length of the soldering sections  122 , so that the two lugs  116  may cover the whole soldering sections  122  to allow the transparent adhesive  140  to affix the soldering sections  122  and the wires  120  to the lugs  116 . 
     The soldering sections  122  of the aforementioned wires  120  are located between the two guide pieces  114 , and the transparent adhesive  140  may appropriately flow into the opening  112   a  and wrap around or contact the LED  130  to attach the soldering sections  122  of the wires  120  to the two guide pieces  114  and the edge of the opening  112   a . The transparent adhesive  140  may use an adhesive or glue bulk with a curing function, such as an ultraviolet-curable adhesive that may be cured by ultraviolet radiation. Finally, the transparent adhesive  140  may exert a fixing or adhesive effect after being cured. 
     As shown in  FIG. 1 ,  FIG. 2  and  FIG. 3 , the two guide pieces  114  and the transparent adhesive  140  may achieve a movement-restricting effect on the soldering sections  122  in a horizontal direction, so as to avoid a soldering failure of the LED  130  due to bending of the soldering sections  122  in the horizontal direction. The two lugs  116  may achieve a movement-restricting effect on the soldering sections  122  in a vertical direction, so as to avoid the soldering failure of the LED  130  due to bending of the soldering sections  122  in the vertical direction. 
     As shown in  FIG. 4  and  FIG. 5 , a light string package structure  100  disclosed by another embodiment of this disclosure is illustrated. As shown in the figure, the thickness and width of two lugs  116  may vary, as long as a distance between two ends of the two lugs  116  is equal to or greater than a length of a soldering section  122  to allow the two lugs  116  to cover the whole soldering section  122 . 
     As shown in  FIG. 6 ,  FIG. 7  and  FIG. 8 , an assembling method of a light string package structure  100  of this disclosure is illustrated. 
     As shown in  FIG. 6 , firstly, one or more wires  120  are prepared, and portions of insulating layers  123  such as plastic layers or insulating paint coating layer are removed by means of stripping, burning or grinding, cutting under tension, and so on, so as to form soldering sections  122 . Secondly, a soldering surface  134  of a LED  130  is soldered to the soldering sections  122 , the soldering sections  122  are flatly attached to the soldering surface  134 , and a light emitting surface  132  faces a direction away from the soldering sections  122 . 
     As shown in  FIG. 7 , an opening  112   a  of a body  112  is aligned with the LED  130 , and the bottom of the body  112  covers the LED  130 , so that the LED  130  is located at the opening  112   a , and the light emitting surface  132  faces the interior of the body  112 . Meanwhile, the wires  120  are located between two guide pieces  114 . 
     As shown in  FIG. 7 , a transparent adhesive  140  is coated on a guide trench  114   a  and two lugs  116  so as to wrap the whole soldering sections  122 . Furthermore, the transparent adhesive  140  may appropriately overflow to be attached between the edge of the opening  112   a  and the LED  130 , between the soldering sections  122  and the two guide pieces  114 , as well as between the soldering sections  122  and the bottom of the body  112 . 
     As shown in  FIG. 8 , finally, the transparent adhesive  140  is cured. For example, an ultraviolet-curable adhesive is irradiated by ultraviolet radiation to complete the light string package structure  100 . A plurality of soldering sections  122 , LEDs  130  and light-transmitting caps are continuously disposed on the wires  120  to form a light string. The aforementioned procedure of disposing the plurality of soldering sections  122 , LEDs  130  and light-transmitting caps may be a one-by-one arrangement or batch operation. For example, the soldering sections  122  are produced in batches, the LEDs  130  are soldered in batches, the light-transmitting caps are arranged in a coverage manner in batches, and gluing and curing are performed in batches. 
     As shown in  FIG. 8  and  FIG. 9 , in the first and second embodiments of this disclosure, the quantity of the wires  120  is not limited, that is, there may be two, three, four or an any quantity of wires, as long as the soldering sections  122  are located between the two guide pieces  114 , and the transparent adhesive  140  attaches the LED  130  to the light-transmitting cap  110 . 
     As shown in  FIG. 10  and  FIG. 11 , in the first and second embodiments of this disclosure, the light string package structure  100  may further include a light guide  150 . The light guide  150  is received into the body  112  through the opening  112   a , and has one end facing the LED  130  to receive light and one end extending towards the front end of the body  112 . The transparent adhesive  140  may appropriately overflow to be attached between the light guide strip  150  and the body  112  to fix the light guide strip  150 . 
     As shown in  FIG. 12 , when the LED  130  emits light, the light may be guided by the light guide  150  and uniformly emitted from the body  112  via the light guide  150 , such that light emissions are concentrated at the opening  112   a.    
     Referring to  FIG. 13 , the light guide  150  may be a cone or a cylinder, or may comprise columns with other cross section forms, as long as one end of the light guide  150  faces the LED  130  to receive the light, and the other end of the light guide strip  150  extends towards the front end of the body  112 . In an embodiment, light guide  150  is a substantially solid structure, though in other embodiments, light  150  may include hollow portions to achieve a transmissive lighting effect that differs from a solid-material light guide. 
     By adopting the light string package structure  100 , in addition to providing an optical effect through the light-transmitting cap, the fixing of the soldering sections  122  can be reinforced, thereby avoiding the soldering failure of the LED  130  due to the excessive bending of the soldering sections  122  in a use process of a light string.