Abstract:
A shunt device for use in a light socket includes a first semiconductor chip and a first container having a receiving surface for receiving the first semiconductor chip therein and having an open surface through which the first semiconductor chip is exposed and a first conductive member connected having a first end connected to the first semiconductor chip through the open surface and a second end connected to a first of the terminals with the socket and wherein the container and the chip and the member are operatively interposed in a self retained manner between the terminals in the lower portion of the socket.

Description:
This is a continuation-in-part of co-pending application U.S. Ser. No. 10/611,744 filed Jul. 1, 2003. 
    
    
     FIELD OF INVENTION  
       [0001]     The present invention relates to a lamp socket for light strings having lights arranged in series. More particularly, the invention relates to a semiconductor chip container with chip therein for use in a light socket forming a shunt to allow for electricity to continually conduct throughout the light string keeping the remainder of the lights lit when one or more lights on the string burn out, become dysfunctional or are removed from a socket.  
       BACKGROUND OF THE INVENTION  
       [0002]     Decorative light strings which are connected in series are highly popular in the United States, especially during holidays in November and December. A drawback with such light strings is that they commonly include of a plurality of individual light units with bulbs which are electrically connected in series and not in parallel. The bulbs are typically incandescent bulbs having a filament formed between two leads of the bulb, the filament giving off light when a current is passed from one lead to the other, through the filament. As the bulb is used, over time, the filament will burn out, breaking the series circuit in which the bulb is arranged. This will cause the entire light string to go out unless a backup circuit path is available to bypass the failed filament.  
         [0003]     Presently, inside of the mini-light bulb, there is a backup circuit path having a shunt system arranged in parallel with the filament of each bulb. This shunt is comprised of three turns of aluminum wire with an insulating (oxide) coating. When the filament is intact, current passes through the filament because the resistance of the filament is low compared to that of the insulating material on the shunt. However, when the filament burns out, the voltage across the leads of the bulb increases to the full line potential of 120 volts AC. The actual peak voltage at 120 volts AC is approximately 170 volts. The insulating coating on the shunt wire is designed to break down at a minimum of 40 volts to provide a backup circuit path around the failed filament. However, this ‘shorting’ mechanism only works about 70% of the time. When it fails to operate, the entire series-wired light string goes out.  
         [0004]     One solution that allows the circuit to continue to function when there is a failure as described above is taught in U.S. Pat. Nos. 6,084,357 and 6,580,182 which is issued to the same inventor herein. The solution is to provide a backup circuit path having a semiconductor shunt system arranged in parallel with the filament of each bulb. As described in the above mentioned issued patents, the semiconductor device might be a diode array or back-to-back Zener diodes. In this manner, even if a bulb burns out, breaks, or falls out of its socket, the rest of the light units in the light string remain on because the series circuit remains closed. The system employed in the above issued patents is the shunting of each light bulb in the string with such a semiconductor shunt mounted in a package as the standard DO-41 package. The DO-41 package housing the semiconductor chip is placed inside of each socket and is electrically connected to the light bulb&#39;s conductive connection in the socket.  
         [0005]     In addition, co-pending U.S. application Ser. No. 10/611,744 described a further improvement in wherein a shunt device included a semiconductor chip held in place by a spring-like conductive member. While this improvement has met with success, the shunt device is difficult to work with due to the diode chip size being extremely small (i.e., chip size is 0.028″× 0 . 028 ″) and current implementation is relatively expensive.  
         [0006]     While the functionality of decorative light strings using the inventor&#39;s prior shunt devices work well, there remains a need to improve the shunt device as set forth herein and reduce the cost of producing the decorative light string.  
       BRIEF SUMMARY OF THE INVENTION  
       [0007]     It is an object to improve decorative light strings.  
         [0008]     It is another object to reduce the cost of decorative light strings.  
         [0009]     It is a further object to provide a semiconductor chip operably disposed within a container inside of a light socket.  
         [0010]     Accordingly, an embodiment of the present invention is directed to a shunt device for use in a light socket having a semiconductor chip operably disposed within a container having an open surface through which the semiconductor chip is exposed and held in place by a conductive member which contacts the chip through the open surface. Another embodiment provides for the container and chip to be held in place by conductive leads having ends which plug into electric terminals of the socket. Still another embodiment is directed to a pair of bent conductive members having the container and chip held therebetween. In yet another embodiment, the conductive members can be modified to include retention fingers which are opposing each other in a spaced relationship in a manner to form a retaining seat for the container and chip which can be preferably held therebetween. Still another embodiment provides for a chip and container to be directly connected to each conductive terminal and have a conductive wire interconnecting the two chips, wherein each chip is intended to dissipate half of the power keeping the socket from overheating in cases where too much current is drawn, such as when higher watt light bulbs are used.  
         [0011]     The light socket of the instant invention is for use with a light string having at least two light sockets connected in series via wire segments having associated contact elements. A light bulb is receivable by each socket and can be removed and replaced when a filament of the bulb burns out.  
         [0012]     Other objects will be revealed by the following description and drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]      FIG. 1  is a partial sectional view of one embodiment of the invention.  
         [0014]      FIG. 2  is a partial sectional view of another embodiment.  
         [0015]      FIG. 3  is a partial sectional view of an existing socket.  
         [0016]      FIG. 4  is a partial sectional view of yet another embodiment of the invention.  
         [0017]      FIG. 4   a  is a blow up of a part of  FIG. 4 .  
         [0018]      FIG. 5  is a partial sectional view of still another embodiment of the invention.  
         [0019]      FIG. 6  is a partial sectional view of another embodiment of the invention.  
         [0020]      FIG. 7  is a plan view of a container for a chip for use in the invention.  
         [0021]      FIG. 8  is an exploded side cross sectional view of the container and chip of  FIG. 7  taken through line  8 - 8 .  
         [0022]      FIG. 9  is a perspective of the container and chip of the invention.  
         [0023]      FIG. 10  is a partial sectional view of another embodiment of the invention employing the container and chip of  FIG. 7 .  
         [0024]      FIG. 11  is a partial sectional view of another embodiment employing the container and chip of  FIG. 7 .  
         [0025]      FIG. 12  is a partial sectional view of yet another embodiment of the invention employing the container and chip of  FIG. 7 .  
         [0026]      FIG. 12   a  is a blow up of a part of  FIG. 12  employing the container and chip of  FIG. 7 .  
         [0027]      FIG. 13  is a partial sectional view of still another embodiment of the invention employing the container and chip of  FIG. 7 .  
         [0028]      FIG. 14  is a partial sectional view of another embodiment of the invention employing the container and chip of  FIG. 7 . 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0029]     Referring now to the drawings, the semiconductor chip of the present invention is generally designated by the numeral  10 . The semiconductor chip  10  is a relatively flat and thin plate which is of the type described in co-pending application Ser. No. 10/611,744. The chip  10  is used in various embodiments described herein. The chip  10  is very small having a size of about 0.028″×0.028″. The handling of this chip  10  is difficult from an integration and cost standpoint into a socket  12 .  
         [0030]     Accordingly, the improvement in present invention provides a container  1000  made of a nonconductive material such as plastic. The container  1000  can include a pair of interconnectable members  1002  and  1004  which are here shown by way of example to be rectangular, but it is recognized that other shapes can be employed. Members  1002  and  1004  can be of a dimensional size of about 0.20″×0.20″ for ease of insertion. The member  1002  includes tab retention surface  1006  which extends inwardly from a mating surface  1008  and tab  1100  which extends outwardly from the mating surface  1008 . Likewise, member  1004  includes tab retention surface  1012  which extends inwardly from a mating surface  1014  and tab  1016  which extends outwardly from the mating surface  1014 . The members  1002  and  1004  can be mated such that the tabs  1010  and  1016  are of a size, configuration and orientation to be received within the respective tab retention surfaces  1012  and  1006  in a friction fit manner to retain the members  1002  and  1004  together. In addition, a chip receiving surface  1018  extends inwardly from mating surface  1008  and a chip exposing surface  1020  extends inwardly from an outer surface  1022  terminating into a shoulder surface  1024  which connects to the chip receiving surface  1018 . Likewise, a chip receiving surface  1026  extends inwardly from mating surface  1014  and a chip exposing surface  1028  extends inwardly from an outer surface  1030  terminating into a shoulder surface  1032  which connects to the chip receiving surface  1026 . The chip receiving surfaces  1018  and  1026  are slightly larger than the dimensions of the chip  10 . The mating surfaces  1008  and  1014  can preferably be generally planar and flat to provide for a mating connection without a gap therebetween, save for the described receiving surfaces  1018  and  1026 . Prior connecting the members  1002  and  1004 , the chip  10  is disposed in chip receiving surface  1018 , for example, to rest on shoulder surface  1024 . Then, the member  1004  is mated with member  1002  as described to secure the chip in a retained manner within the receiving surfaces  1018  and  1026 .  
         [0031]      FIG. 1  shows a modified light socket  12  having conductive terminals  14  on each side with plug-in socket surfaces  16  formed therein in a portion of each terminal  14  where a light bulb  17  normally seats when operatively disposed within the socket  12 . The light bulb  17  has a pair of conductive leads which connect to a filament contained within a glass envelope. The chip  10  may include operatively connected conductive leads  18 , wherein one lead  18  extends from each side  20  and  22  of the chip  10  and can be bonded thereto by a conductive epoxy, for example. A terminal end  24  of each lead  18  is configured to be operatively received into the plug-in socket surfaces  16 . The leads  18  can be of a suitable conductive material such as copper.  FIG. 10  shows a similar embodiment with the container  1000  having chip  10  therein operably disposed between the leads  18 .  
         [0032]      FIG. 2  shows an alternative embodiment wherein the semiconductor chip  10  is bonded to bent conductive members  126  which each have an inwardly disposed flange  124 . The socket  120  has a housing  121  to receive the light bulb  17  and a pair of opposing conductive terminals  122 . The terminals  122  are connected to wires  125  which operatively extend outside the housing  120 . The chip  10  can be bonded, e.g., with an epoxy, to flange  124 . When operatively disposed, the chip  10  is disposed adjacent and between the flanges  124 .  FIG. 11  shows a similar embodiment with the container  1000  having chip  10  therein operably disposed between the bent ends  124  having a detent portion  127  for contacting and securing the container  1000  and chip  10 . Similarly, an epoxy can be employed to bond the container  1000  and chip  10  to at least one of the flanges  124 .  
         [0033]      FIG. 3  shows an existing socket  12 ′ and bulb  17 . The socket  12 ′ shorts when the bulb  17 ′ is removed.  
         [0034]     In yet another embodiment,  FIG. 4  shows bent conductive terminals  50  and  52  having retention fingers  54  and  56 , respectively, which are opposing each other in a spaced relationship such that the fingers  54  and  56  do not touch. The terminals  50  and  52  contact conductive terminals  140 . The fingers  54  and  56  can be set at an angle to aid in this regard. When operatively disposed in socket  150 , the fingers  54  and  56  form part of a retaining seat for chip  10  along with lower portions  58  and  60  of the terminals  50  and  52 , respectively. The chip  10  can be inserted between terminals  50  and  52  so that the terminals  50  and  52  do not touch.  FIG. 12  shows a similar embodiment with the container  1000  having chip  10  therein operably disposed between the lower portions  58 ′ and  60 ′. As seen in  FIG. 12   a , lower portions  58 ′ and  60 ′ can be formed with a detent  59 ′ and  61 ′ which serve to contact the chip  10  through the open surfaces  1020  and  1028 .  
         [0035]     Still another embodiment shown in  FIG. 5  provides for chips  10  and  10 ′ (which are similarly constructed) to be conductively directly connected to conductive terminals  200  and  200 ′ within socket  202 . Again, the chips  10  and  10 ′ can be bonded directly to the terminals  200  and  200 ′ on one side. A conductive wire  250  interconnects the two chips  10  and  10 ′ and likewise the ends of the wire  250  can be press fit between (and optionally bonded) to the other side of each respective chip  10  and  10 ′. Each chip  10  and  10 ′ is intended to dissipate half of the power keeping the socket  202  from overheating in cases where too much current is drawn, such as when higher watt light bulbs are used.  
         [0036]      FIG. 13  shows a similar embodiment with the container  1000  having chip  10  therein operably disposed between the leads wire  250 . Here, terminals  201  and  201 ′ can include an inwardly protruding portion  203  and  203 ′ to assure contact of the chip  10  within the container  1000 .  
         [0037]      FIG. 6  shows another embodiment. Here, the operation is similar to that of  FIG. 5 . However, a conductive compression spring  300  is used to connect chips  10  and  10 ′ with each end of the spring  300  conductively connected to one side of the respective chips  10  and  10 ′. The spring  302  is configured to bias the chips  10  and  10 ′ into retained conductive contact with terminals  302  and  302 ′ in socket  350  below where the light bulb  17  is operatively seated. Once operatively disposed in the socket  350 , the chips  10  and  10 ′ can be bonded to the terminals  302  and  302 ′, if desired, or contact allowed to be made by the compression spring  300 .  FIG. 14  shows a similar embodiment with the container  1000  having chip  10  therein operably disposed between the spring  300 . Here, terminals  302  and  302 ′ can include an inwardly protruding portion  303  and  303 ′ to assure contact of the chip  10  within the container  1000 .  
         [0038]     By way of example, a bottom surface  1034  of the socket  12  shown in  FIGS. 10-14  can include a plug inlet  1036  to receive a plug  1038 . The plug  1036  can be inserted subsequent to the insertion of the container  1000  with chip  10  through the plug inlet  1034 . Once the container  1000  with chip  10  and plug  1038  are inserted, epoxy can be added as necessary or desired for a particular embodiment in order to fix the position of the container  1000  and chip  10  with respect to a particular electrical contact.  
         [0039]     The above described embodiments are set forth by way of example and are not for the purpose of limiting the present invention. It will be readily apparent to those skilled in the art that obvious modifications, derivations and variations can be made to the embodiments without departing from the scope of the invention. Accordingly, the claims appended hereto should be read in their full scope including any such modifications, derivations and variations.