Abstract:
Employing capacitors as shunts in a decorative light string can prevent the circuit from being opened when a lamp burns out or becomes loose in the socket. But manually assembling such a light string is costly and the quality of the resulting string is not assured to be high. The present disclosure introduces a shunted light string, and a method of assembling that light string that is able to be automated to ensure a consistent quality level by reducing or eliminating human workmanship issues.

Description:
CROSS-REFERENCE TO RELATED APPLICATION AND PRIORITY CLAIM 
       [0001]    This application claims the benefit, under 35 U.S.C. §119(e), of United States Provisional Patent Application No. 62/073,136, filed 31 Oct. 2014, entitled “METHOD OF ASSEMBLING SEASONAL LIGHT STRINGS EMPLOYING CAPACITOR SHUNTS,” the entire contents and substance of which is incorporated herein by reference in its entirety as if fully set forth below. 
     
    
     BACKGROUND 
       [0002]    1. Field of the Invention 
         [0003]    Embodiments of the present invention relate to seasonal light strings and, more particularly, to seasonal light strings employing capacitors as a shunt and methods of assembling the same. 
         [0004]    2. Description of the Related Art 
         [0005]    Many different designs for seasonal light strings are known. In the design of traditional seasonal strings, the lamps, either incandescent lamps or light emitting diodes (LEDs), are series connected. If one of the lamps burns out or becomes loose from the socket, the light string circuit will be open and the lights in the series will no longer illuminate. 
         [0006]    In order to allow the circuit to remain closed when a bulb burns out or is loose, a device known as a shunt can be employed. An alumina shunt is one example of what has been employed inside a tungsten incandescent bulb so that when a tungsten filament is burnt out or broken after prolonged use, the outer layer of the alumina shunt wire will evaporate and the alumina shunt will start to conduct electric current. The circuit will remain closed and the remaining lamps can still illuminate. One major drawback of an alumina shunt is that it cannot prevent the circuit from being open when a lamp is off the socket. 
         [0007]    Additional shunts of different sorts have evolved and are placed across the terminals inside the lamp socket. These components are typically assembled by hand, and thus the process is costly sometimes slow compared to other aspects of light string production. 
         [0008]    Accordingly, it would be desirable to have a method of automating or expediting the assembly process of a seasonal light string employing capacitor shunting. 
       SUMMARY 
       [0009]    Owing to the vast supply and low material cost of capacitors, applying capacitors as shunts in a decorative light string is a cost effective means of making an improved decorative light string. However, inserting a capacitor into a lamp socket, in the past, has been a manual procedure performed inefficiently, which can be costly and can induce hidden quality problems. The present invention includes an innovative approach to automate, or expedite and make easier, the tedious assembling procedure of making seasonal light strings employing capacitors as shunts inside each lamp socket. The present invention includes a well controlled process that can help ensure consistent quality and reduce labor cost. 
         [0010]    In some embodiments, a light string according to the present disclosure can comprise a plurality of lamp portions. Each lamp portion can comprise a lamp socket, first and second wire ends positioned within the lamp socket, a capacitor located in the lamp socket, and a lamp sub-assembly located at least partially in the lamp socket. A first lead of the capacitor may be in electrical communication with the first wire end, and a second lead of the capacitor may be in electrical communication with the second wire end. The lamp sub-assembly can comprise a lamp and a lamp housing, with a first lead of a lamp in electrical communication with the first wire end, and a second lead of the lamp in electrical communication with the second wire end. In some embodiments, the lamp portions are in electrical communication with each other, and disposed at intervals along a length of wire. 
         [0011]    In some embodiments, the lamps in the light strings can be incandescent bulbs. In some embodiments, the lamps in the light strings can be light emitting diodes. The capacitors in the lamp housings can have a capacitance of about 10 μF to 500 μF and a voltage rating of about 1V to 200V. Some applications can have capacitors can have a capacitance of about 30-1000 μF and a voltage rating of about 12-20V. The capacitors may be of the non-polarized type. 
         [0012]    The present disclosure is also directed to a method of assembling a light string, such as the one described above. The method can include several steps that can be done by hand or automated. First, the method can include feeding a one or more wires into a lamp socket. In some embodiments, a length of wire can be cut, resulting in the first end and the second end of the wire. These wire ends may then be stripped, and the ends can be connected to wire terminals by crimping, soldering, twisting, inserting, or splicing. In some embodiments, these wire terminals may then be positioned into slots located on an interior surface of the lamp socket. 
         [0013]    Next, the method can include inserting a capacitor into the lamp socket such that a first lead of the capacitor is in electrical communication with a first end of the one or more wires, and a second lead of the capacitor is in electrical communication with a second end of the one or more wires. In some embodiments, the capacitor may be of a type as discussed above. 
         [0014]    Finally, the method can include inserting a lamp sub-assembly into the lamp socket such that a first lead of the lamp is in electrical communication with the first end of the wire, and a second lead of the lamp is in electrical communication with the second end of the wire. The lamp sub-assembly can include a lamp and a lamp housing, and may be assembled prior to the assembly of the light string. 
         [0015]    Further features of the invention, and the advantages offered thereby, are explained in greater detail hereinafter with reference to specific embodiments illustrated in the accompanying drawings, wherein like elements are indicated by like reference designators. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]      FIG. 1  is a schematic of an electrical circuit of a seasonal light string according to an embodiment of the present disclosure. 
           [0017]      FIG. 2  is an exploded view of a single bulb portion in accordance with an exemplary embodiment of the present disclosure. 
           [0018]      FIG. 3  is a cross-sectional view of an assembled single bulb portion in accordance with an exemplary embodiment of the present disclosure. 
           [0019]      FIG. 4  is a schematic process overview showing the material inputs and assembly steps around a turntable according to a method in accordance with the present disclosure. 
           [0020]      FIG. 5  is a perspective view of a single bulb portion at the first step of seasonal light string assembly, in accordance with the present disclosure. 
           [0021]      FIG. 6  is a perspective view of a single bulb portion at the second step of seasonal light string assembly, in accordance with the present disclosure. 
           [0022]      FIG. 7  is a perspective view of a single bulb portion at the third step of seasonal light string assembly, in accordance with the present disclosure. 
           [0023]      FIG. 8  is a perspective view of a single bulb portion at the fourth step of seasonal light string assembly, in accordance with the present disclosure. 
           [0024]      FIG. 9  is a perspective view of a single bulb portion at the fifth step of seasonal light string assembly, in accordance with the present disclosure. 
           [0025]      FIG. 10  is a cross-sectional view of a single bulb portion at the fifth step of seasonal light string assembly, in accordance with the present disclosure. 
           [0026]      FIG. 11  is a perspective view of a capacitor to be installed in the seasonal light string assembly, in accordance with the present disclosure. 
           [0027]      FIG. 12  is a perspective view of a single bulb portion and capacitor at the sixth step of seasonal light string assembly, in accordance with the present disclosure. 
           [0028]      FIG. 13  is a perspective view of a single bulb portion at the seventh step of seasonal light string assembly, in accordance with the present disclosure. 
           [0029]      FIG. 14  is a perspective view of a single bulb portion after it has been assembled in accordance with the present disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0030]    To facilitate an understanding of the principles and features of the various embodiments of the invention, various illustrative embodiments are explained below. Although exemplary embodiments of the invention are explained in detail as being systems and methods for assembling seasonal light strings employing a capacitor as a shunt, it is to be understood that other embodiments are contemplated, such as embodiments employing other types of light strings, shunting devices, materials, and the like. Accordingly, it is not intended that the invention is limited in its scope to the details of construction and arrangement of components set forth in the following description or examples. The invention is capable of other embodiments and of being practiced or carried out in various ways. Also, in describing the exemplary embodiments, specific terminology will be resorted to for the sake of clarity. 
         [0031]    It must also be noted that, as used in the specification and the appended claims, the singular forms “a,” “an” and “the” include plural references unless the context clearly dictates otherwise. For example, reference to a component is intended also to include composition of a plurality of components. References to a composition containing “a” constituent is intended to include other constituents in addition to the one named. 
         [0032]    Also, in describing the exemplary embodiments, terminology will be resorted to for the sake of clarity. It is intended that each term contemplates its broadest meaning as understood by those skilled in the art and includes all technical equivalents which operate in a similar manner to accomplish a similar purpose. 
         [0033]    Ranges may be expressed herein as from “about” or “approximately” or “substantially” one particular value and/or to “about” or “approximately” or “substantially” another particular value. When such a range is expressed, other exemplary embodiments include from the one particular value and/or to the other particular value. 
         [0034]    By “comprising” or “containing” or “including” is meant that at least the named compound, element, particle, or method step is present in the composition or article or method, but does not exclude the presence of other compounds, materials, particles, method steps, even if the other such compounds, material, particles, method steps have the same function as what is named. 
         [0035]    It is also to be understood that the mention of one or more method steps does not preclude the presence of additional method steps or intervening method steps between those steps expressly identified. Similarly, it is also to be understood that the mention of one or more components in a composition does not preclude the presence of additional components than those expressly identified. 
         [0036]    The materials described as making up the various elements of the invention are intended to be illustrative and not restrictive. Many suitable materials that would perform the same or a similar function as the materials described herein are intended to be embraced within the scope of the invention. Such other materials not described herein can include, but are not limited to, for example, materials that are developed after the time of the development of the invention. 
         [0037]    To facilitate an understanding of the principles and features of this disclosure, various illustrative embodiments are explained below. In particular, various embodiments of this disclosure are described as a method for assembling seasonal light strings employing a capacitor as a shunt. Some embodiments of the invention, however, may be applicable to other contexts, and embodiments employing these applications are contemplated. For example and not limitation, some embodiments of the invention may be applicable to various types of light strings and shunting devices as desired. 
         [0038]      FIG. 1  illustrates a circuit diagram of an exemplary seasonal light string in accordance with the present disclosure. Circuit  100  can include an electrical source  110  that provides, for example and not limitation, 120V of alternating current at 60 Hz. In some embodiments according to the present disclosure, source  110  is a standard home electrical outlet. Source  110  could also be a direct current source in the case of a battery operated light string or device. 
         [0039]    Circuit  100  can further include a series of lamps  120 . In some embodiments according to the present disclosure, lamps  120  are incandescent light bulbs. Alternatively or in combination, lamps  120  can be light emitting diodes (LEDs). As  FIG. 1  illustrates, circuit  100  can include capacitors  130  connected in parallel to lamps  120 . In some embodiments according to the present disclosure, each lamp  120  can have a capacitor  130  connected in parallel, and each pairing of lamp  120  and capacitor  130  can be connected in series. 
         [0040]    In order to select an appropriate capacitor, several factors can be considered. In order for the capacitor to properly shunt a circuit, an appropriate capacitance should be selected. To ensure that the capacitor does not over heat and produce an unsafe condition, a capacitor having an appropriately high voltage rating should be selected. Due to the size of a typical lamp in a light string, sizing of the capacitor also should be considered. Relatedly, due to the potentially high number of lamps in a decorative light string, cost can also be a consideration in capacitor selection. For example and not limitation, capacitor  130  can be selected to have a capacitance of 1 μF to 500 μF and a voltage rating of 1V to 200V. In an exemplary embodiment of the present disclosure, the capacitor is selected to have a rating of 47-100 μF and 16V, and may be of the non-polarized type. By way of example and not limitation, an embodiment may include a 68 μF, 16V non-polarized capacitor having dimensions of approximately 5 mm by 8 mm. 
         [0041]      FIG. 2  depicts an exploded view of a single bulb portion  200 . In the embodiment shown in  FIG. 2 , each lamp portion  200  is located along wire  210 . Each lamp portion can include a lamp  220 , lamp housing  225 , capacitor  230 , lamp socket  240 , and terminals  250 .  FIG. 3  shows a cross-section of the components of lamp portion  200  in a fully assembled state. In some embodiments, a shoulder portion of lamp housing  225  abuts lamp socket  240  and secures lamp  220  therein. 
         [0042]    An exemplary method  400  of producing a seasonal light string is represented in  FIG. 4 .  FIG. 4  shows the steps to be performed at each location around turntable  410 . The method  400  may be performed by any number of devices or machines, with or without human assistance. In some embodiments, all of the method steps are performed automatically. However, it is contemplated that none or not all of the method steps are automated. 
         [0043]    Turntable  410  can be one of many different types of workstations. Due to the selection of components and the particulars of the process steps, turntable  410  may be a fully automated machine. In some embodiments, turntable  410  is a self-powered rotating table. Some embodiments may require or allow for human intervention in the process of advancing the light string along or around turntable  410 . In some embodiments, turntable  410  can be a linear conveyor belt or work station. The steps of a method according to the present disclosure may be performed at various locations along or around turntable  410 , or they could be performed at a single location while the necessary components are provided to the single location. 
         [0044]    Step  415  involves having wire  210  fed into the turntable from a spool. The wire is then measured according to the specification for the particular seasonal light string to be produced, and the lamp sockets  240  are positioned appropriately (steps  420  and  425 ). The result of step  425  is illustrated in  FIG. 5 . The wire  210  is then cut (step  430 ), and  FIG. 6  shows the lamp portion  200  and the wire  210  afterwards. Once wire  210  has been cut, the cut ends of wire  210  are stripped and prepared for further assembly (step  435 ). The cut and stripped ends of wire  210  are shown in  FIG. 7 . In some embodiments, the cutting and stripping can be done in advance of positioning the lamp sockets. 
         [0045]    At this point along turntable  410 , terminals  250  may be fed to the wire  210  (step  440 ), and then they are attached to the cut ends of the wire  210  (step  445 ). In some embodiments the terminals are attached to the cut ends of the wire by crimping, soldering, twisting, inserting, and/or splicing.  FIG. 8  illustrates lamp portion  200  once terminals  250  have been attached to the wire  210 . The terminals  250  are then pulled into lamp socket  240  such that they seat in slots located on either side of the socket (step  450 ).  FIG. 9  shows the outside view of lamp portion  200  with terminals  250  seated within lamp socket  240 , and  FIG. 10  shows a cross-sectional view of the assembly in  FIG. 9 . 
         [0046]    Step  455  provides that capacitors  230  are fed to turntable  410 . In some embodiments, this is done by a vibration feeder or other type of feed system known in the art. The capacitor in its original and its ready-to-install states are illustrated in  FIG. 11 . Capacitor  230  has two leads  235  that are manipulated such that they go from projecting downward and away from capacitor  230  to a ready-to-install state wherein leads  235  project upward and along the sides of capacitor  230 . This manipulation may be done either before or after being fed to turntable  410  in any number of ways known in the art such as by hand or by mechanical process. Once capacitors  430  are in their ready-to-install state and have been fed to turntable  410 , they can be inserted into lamp socket  240  as seen in  FIG. 12  (step  460 ). Once inserted, leads  235  will be in electrical communication with terminals  250 . 
         [0047]    At step  465  around turntable  410 , pre-assembled lamp sub assemblies are fed into the system. Each lamp sub assembly has a lamp  220  and lamp housing  225 .  FIG. 13  illustrates the lamp  220  and lamp housing  225  assembled and ready to be installed into lamp socket  240 .  FIG. 14  depicts the completed lamp portion  200 , after the lamp has been inserted (step  470 ). Once all of the components of each lamp portion  200  of the light string have been properly assembled, the light string is finished (other components are added, such as plugs at the end of the light strings) and passed from turntable  410  to a spool to be stored and/or prepared for packaging and shipping (step  475 ). 
         [0048]    From the foregoing, it can be seen that the invention provides a method of production, which can be used to produce capacitor-shunted light strings. It will be appreciated by those skilled in the art, however, that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics thereof. For example, while the invention has been described in the context of a capacitor-shunted seasonal light string, the concepts described herein need not be limited to this illustrative embodiment. For example, light strings having different shunting devices can be constructed using the same or similar method, and would enjoy the same benefits as described above. Additionally, the specific configurations, choice of materials, and the size and shape of various elements, including the lamps and sockets, could be varied according to particular design specifications or constraints requiring a seasonal light string or decoration to meet additional of different design parameters. Such changes are intended to be embraced within the scope of the invention. 
         [0049]    The presently disclosed embodiments are, therefore, considered in all respects to be illustrative and not restrictive. The scope of the invention is indicated by the appended claims, rather than the foregoing description, and all changes that come within the meaning and range of equivalents thereof are intended to be embraced therein.