Patent Publication Number: US-8982579-B2

Title: Electrical assembly

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of U.S. Ser. No. 13/294,095, filed Nov. 10, 2011, entitled Solder-Less Electrical Assembly and Process for its Manufacture, the disclosure of which is specifically incorporated herein by reference. This application is related to two other patent applications being filed the same day that are also continuation-in-part applications of U.S. Ser. No. 13/294,095, the disclosures of which are also incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention is in the field of solder-less electrical assemblies. 
     BACKGROUND OF THE INVENTION 
     Electrical assemblies have long used lead solder to help make and keep electrical connections. However, use of solder, and especially lead solder, has come under increasing criticism due to environmental concerns. 
     The present invention is especially well-suited for, but not limited to use in, footwear, wearing apparel and toys. For an electrical assembly to be useful in such fields it must be compact and inexpensive to manufacture. This means that both the number of parts, as well as the number of manufacturing steps, must be kept to the bare minimum if one is to be competitive in the world today. 
     The present invention advances simple, compact and easy to manufacture electrical assemblies that are well-suited for use in a variety of applications, including footwear, apparel and toys. 
     The present invention improves upon prior inventions of the same inventor, including U.S. Pat. Nos. 7,147,337 and 8,004,856. 
     SUMMARY OF THE INVENTION 
     The present invention is generally directed to an electrical assembly having a battery block, a battery held within a battery block opening in the battery block, a PCB with a first end held within a PCB opening in the battery block and two conductors held within the battery block, each of which has a first lead in mechanical and electrical contact with the battery without the use of any solder and a second lead in mechanical and electrical contact with the PCB without any use of solder. 
     The two conductors can have a u shape before they are assembled to the battery block assembly and at least one of their leads can be bent over during assembly so it is in lengthwise electrical contact. The battery block opening can be defined by a substantially planar top surface, a substantially planar bottom surface and a curved side slot wall that connects the substantially planar top surface to the substantially planar bottom surface, the battery block opening being adapted to receive and hold a battery (such as a button battery) which can have approximately half of the battery extending out from the battery block when it is inserted into the battery block opening and is proximate the curved side slot wall. 
     An assembly according to the present invention can be assembled by affixing two conductors to a battery block without the use of solder, inserting a PCB into a PCB opening in the battery block and inserting a battery into a battery block opening in the battery block. Each of the two conductors will have a first lead in mechanical and electrical contact with the battery without the use of any solder and a second lead in mechanical and electrical contact with the PCB without any use of solder. As a result of such assembly, the PCB is held within the PCB opening by a mechanical fit without the use of any solder. 
     Accordingly, it is a primary object of the present invention to provide an improved solder-less assembly. 
     This and further objects and advantages will be apparent to those skilled in the art in connection with the drawings and the detailed description of the invention set forth below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded assembly drawing illustrating one electrical assembly according to the present invention while  FIG. 2  is a cross sectional view of the assembly of  FIG. 1  in an unexploded state. 
         FIG. 3  illustrates a battery block of the electrical assembly of  FIG. 1  showing the block with its battery removed, looking into a side view from the direction in which a battery would be inserted,  FIG. 4  is a partially exploded view of  FIG. 3 , and  FIG. 5  is an assembled view of  FIG. 3 . 
         FIG. 6  is a side view of the electrical assembly of  FIG. 1  while  FIG. 7  is a partially exploded view of  FIG. 6 .  FIGS. 6A-6C  illustrate contact being made between a PCB trace and a wire with a slit in its insulative covering. 
         FIG. 8  illustrates the electrical assembly shown in  FIG. 1  in a closed state, with multiple LEDs held in multiple wires of a ribbon wire. 
         FIG. 9  illustrates an LED block which holds an LED at an end of a wire pair while  FIG. 10  is an exploded view of  FIG. 9 . 
         FIG. 11  is a top view of an LED block illustrating how the LED leads are aligned to connect with the wire while  FIG. 12  illustrates the wire pair inserted into the LED block and how the LED leads will align with conductive members of the wire pair. 
         FIG. 13  is a side view of an LED block showing an LED to be inserted while  FIG. 14  illustrates its insertion.  FIG. 13   a  shows an alternative embodiment to  FIG. 13  in which the LED lead cavities are angled to facilitate alignment. 
         FIG. 15  illustrates how an LED block can channel and align LED leads to make contact with conductive members of a wire pair while  FIG. 16  illustrates insertion of an LED into an end of a wire pair. 
         FIG. 17  illustrates an interconnector of two ribbon wires. 
         FIG. 18  is an exploded view of the interconnector while 
         FIG. 19  is a phantom side view of  FIG. 17 , assembled and connected. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention details how various parts can easily be assembled without the use of solder. Although not limited to a final assembly, the present invention is especially well suited to assembly of a package useful for controlling lighting of multiple light emitting diodes (“LEDs”) through movement, which itself is useful in a variety of products, such as, for example, footwear, clothing and toys. It bears note, however, that techniques and assemblies described herein in connection with such usage can be applied to many additional fields. 
     In the Figures and the following description, number designations indicate various features of the invention, with like number designations referring to like features throughout both the drawings and the description. Although the Figures are described in greater detail below, the following is a glossary of the elements identified in the Figures. 
     GLOSSARY 
     
         
           1  electrical assembly 
           10  battery 
           10   b  bottom surface of battery  10   
           10   n  negative surface of battery  10   
           10   s  side surface of battery  10   
           11  battery block 
           12  battery opening (in battery block  11 ) 
           13  column 
           15  conductor 
           15 . 1  first lead of conductor  15   
           15 . 2  second lead of conductor  15   
           16  conductor 
           16 . 1  first lead of conductor  16   
           16 . 2  second lead of conductor  16   
           17  top surface 
           18  bottom surface 
         PCB opening (in battery block  11 ) 
           20  switch assembly 
           20 . 1  first switch assembly lead 
           20 . 2  second switch assembly lead 
           30  printed circuit board (“PCB”) 
           31  radius (in PCB  30 ) 
           32  conductive traces and pads 
           33  electronics 
           40  ribbon block assembly 
           41  ribbon block 
           42  PCB opening (in ribbon block  41 ) 
           43  ribbon opening (in ribbon block  41 ) 
           50  ribbon wire assembly 
           51  conductive wire 
           52  insulative covering (surrounding a conductive wire  51 ) 
           53  stripped portion of insulative covering  52   
           60  light emitting diode (“LED”) 
           61 . 1  first LED lead 
           61 . 2  second LED lead 
           62  sharp pin point 
           65  LED base 
           70  LED block 
           71  wire hole 
           72  LED lead cavity 
           73  cavity (in which LED  60  is seated) 
           74  stress reliever 
           100  outer case 
           101  case cover 
           102  case bottom 
           103  male member 
           104  female member 
       
    
       FIG. 1  illustrates an assembly, shown generally as  1 , that has multiple subcomponents that are assembled together—one or more batteries  10 , a battery block  11 , a switch assembly  20 , a PCB  30 , a ribbon block assembly  40 , and two conductors,  15  and  16 . The ribbon block assembly  40  may have its own subassemblies attached to its other end, and/or support multiple LEDs in parallel, as will be discussed below. 
     Battery  10 , in an especially preferred embodiment, is a lithium 3 volt button cell battery. This type of battery allows positive electrical contact to be made with its upper negative surface  10   n  and positive electrical contact to be made with either its side surfaces  10   s  or its bottom surface  10   b . In an alternative embodiment, more than one battery can be stacked on top of each other. 
     Battery block  11 , shown in  FIGS. 3-5 , in an especially preferred embodiment, is molded from resilient material, such as plastic. Two conductors,  15  and  16 , are attached to battery block  11  in either one or two assembly steps. Conductors  15  and  16  can be forced through a wall of battery block  11  or preformed holes or pilot holes (not shown) can be used to assist in this assembly step. Conductors  15  and  16 , which might be thought of as resembling u-shaped staples, are made of electrically conductive materials and each has two leads that extend down into an interior cavity of battery block where they will make electrical contact as is described later. In one embodiment of the invention, conductors  15  and  16  are staples that are assembled by a stapling step. 
     After conductors  15  and  16  have been assembled to battery block  11 , battery  10  is inserted into battery opening  12  formed in battery block  11  where it will be held in place by an interference fit. During insertion of battery  10  into battery opening  12 , first lead  15 . 1  of conductor  15  will come into contact with negative surface  10   n  of battery  10  and be bent over due to the insertion process (see  FIG. 6 ) to secure electrical contact with the battery. Bending first lead  15 . 1 , in an especially preferred embodiment, also assists with creating a more secure interference fit to hold battery  10  in place due to resiliency of the battery block material which forces now bent first lead  15 . 1  against battery  10 . During the same insertion step first lead  16 . 1  of conductor  16  will make positive electrical contact with battery  10  and, in an especially preferred embodiment, the electrical contact will be made with a side surface  10   s  of battery  10 . Making electrical contact with side surface  10   s  is especially preferred because it allows both conductors  15  and  16  to be assembled to the same surface of battery block  11 , although conductor  16  could alternatively be assembled to a bottom surface and make electrical contact with bottom surface  10   b  of battery  10  in the same manner as was done with electrical conductor  15  and negative surface  10   n.    
       FIGS. 3-5  show an especially preferred embodiment of the present invention in which three columns or ribs  13  help stabilize battery block  10  when a PCB  30  is inserted into PCB opening  19  in battery block  11 . Each column  13  provides structural support to prevent top surface  17  from bowing away from bottom surface  18 , thus helping to maintain electrical contacts with PCB  30 , and PCB  30  has channels (see  FIG. 4 ) that are designed to receive columns  13  to provide a mating fit. In an especially preferred embodiment, each frictionally formed electrical lead (e.g.,  15 . 1  and  16 . 1 ) is supported by its own unique channel of resilient housing formed by at least one column  13  and each unique channel is independently resilient. 
     After battery  10  is inserted into battery block  11 , switch assembly  20  can be assembled to battery block  11 . Switch assembly  20  can be designed so that it fits into an opening in battery block  11  and can be held in place by an interference fit. Switch assembly  20  has first and second switch assembly leads  20 . 1  and  20 . 2  that extend into PCB opening  19  in battery block  11 . Switch assembly  20  can be constructed so that it extends above battery block  11 , as shown in  FIG. 1 , although it is preferable that the top of switch assembly  20  is flush with battery block  11  so as to make a more compact assembled module. Also, although  FIG. 1  shows the opening in which switch assembly block  20  is inserted has three sides, it need not be so, and could instead be a four-sided opening formed near the end of battery block  11  where PCB  30  is inserted. The details of switch assembly  20  are not critical to the present invention, and any number of different switch assemblies can be used, an example of which is U.S. Pat. No. 7,347,577, the details of which are specifically incorporated herein by reference. 
     After switch assembly  20  has been assembled to battery block  11  (see  FIG. 1 ), PCB  30  is inserted into PCB opening  19 . PCB  30  can carry a variety of electronics, shown generally as  33 , to control electrical function of electrical assembly  1 . (Electronics  33  can include, but do not necessarily need to include, a microprocessor.) Electronics  33  can be pre-mounted on PCB  30  before PCB is assembled to battery block  11 . PCB  30  has multiple conductive traces  32  aligned so that when PCB  30  is inserted into PCB opening  19  they will make electrical contact with second lead  15 . 2  of conductor  15 , second lead  16 . 2  of conductor  16 , and first and second switch assembly leads  20 . 1  and  20 . 2 , and it is especially preferred that insertion of PCB  30  causes leads  15 . 2  and  16 . 2  to bend over so as to secure electrical contact and also assist with creating an interference fit. PCB  30 , in an especially preferred embodiment, has a radius  31  ( FIG. 4 ) that increases the surface area for contact and PCB  30  is held within battery block  11  by an interference fit. Because battery block  11  is made of a resilient material, once PCB  30  has been inserted into PCB opening  19  and the four leads are electrically connected, the housing will bias the leads, each in its own unique channel, against their respective conductive members of PCB  30 . PCB  30  can also have either male or female mating members (not shown) designed to mate in a snap fit fashion with corresponding female or male mating members in either or both of battery block  11  and ribbon block  41 . Alternatively, and in an especially preferred embodiment, PCB  30  does not have any male or female mating members and, instead, battery block  11  and ribbon block  41  snap fit together, holding PCB  30  inside, so as to create a small, self-contained module that can be used, for example, in footwear, clothing and other uses. Such a module can have transparent or translucent walls and also contain one or more LEDs positioned within such walls that can be seen through the walls when the module is appropriately positioned in footwear, clothing or the like. 
     After PCB  30  is inserted into PCB opening  19  of battery block  11  it is then inserted into PCB opening  42  of ribbon block  41 , although the order of such assembly steps can be reversed. 
     Ribbon block assembly  40  is an assembly of ribbon block  41  and ribbon wire assembly  50 . Ribbon wire assembly  50  has at least one conductive wire  51 , and usually groups of multiple conductive wires  51 , each of which has an insulative covering  52  surrounding it, with a portion of insulative covering  52  being stripped away (shown as  53  in  FIG. 7 ) so as to allow electrical contact to be made with the conductive wire. It is especially preferred that insulative covering  52  is only stripped away where electrical contact is to be made with the conductive wire and the back half of insulative covering  52  remains in place, as such back covering will assist in making a more secure electrical contact upon assembly when it is compressed by a forced connection between the exposed area of the conductive wire and the electrical conductor member to which it is being electrically connected. 
     Ribbon block assembly  40  is inserted into ribbon opening  43  of ribbon block  41  where it is held in place by an interference fit. Once PCB  30  is fully inserted into PCB opening  42 , conductive traces  32  will make electrical contact with conductive wires  51  at exposed portions  53  of insulative covering  52  (see  FIG. 6 ). It has been found that such electrical contact can be made without the need to use through hole PCB connections, which reduces the cost of the PCB  30  needed in accordance with the present invention, by causing the exposed conductive wire to be bent over a top of PCB  30 . (While it has been found that through hole PCB connections are not required for use with ribbon wire LEDs, to be described later, there may be other uses of electrical assemblies in which through hole PCB connections might be desirous, and such a possibility would still be within the scope of the present invention). It also bears note that the electrical connections formed between PCB  30  and both battery  10  and switch assembly  20  also do not require the use of through hole PCB connections. Finally, in an especially preferred embodiment, instead of stripping insulative covering  52  away, a slit is made in insulative covering  52  and then electrical contact is made between a conductive wire and a conductive trace  32  of a top surface of PCB  30 , as is illustrated in  FIGS. 6A-6C . 
     Electrical assembly  1  of the present invention has many distinct advantages. 
     One major advantage of electrical assembly  1  is that it can be assembled without the use of any solder. This represents a significant advantage, especially as there is more and more concern about environmental effects of solder. 
     Another major advantage of electrical assembly  1  is ease of manufacturing and assembly, which greatly reduces cost. Because solder is not required, no soldering iron steps are required, thus reducing cost. Also, electrical assembly  1  can be manufactured from subcomponents with just six assembly steps without using separate connecting parts, which greatly reduces its cost of manufacture. In a similar fashion, multiple PCBs can be electrically connected together in a single electrical assembly in which multiple PCBS are interconnected by use of one or more ribbon block assemblies. 
     Electrical assembly  1  is particularly well suited for use in applications where it can be used to power LEDs, some examples of which include footwear, clothing and strings of LEDs. In such a use one or more LEDs  60  can be assembled to electrical assembly  1 , without the use of solder, by using a wire block assembly for each LED, which will now be described. 
     Each LED  60  can be assembled to its own pair of conductive wires  51  or multiple LEDs can be assembled on a single pair of conductive wires  51  (see  FIG. 8 ). In an especially preferred embodiment of the present invention, LED leads end with a sharp pin point  62  (see  FIG. 13 ) which is useful in piercing an insulative covering  52  of conductive wires  51 . 
     In accordance with an especially preferred embodiment of the present invention, an LED block  70  (see  FIG. 10 ) has a wire hole  71  into which a pair of conductive wires  51  for a single LED  60  is inserted. In an especially preferred embodiment, illustrated in  FIGS. 9 and 10 , LED block  70  has a stress reliever  74  that extends outwardly around wire hole  71  to lessen stress that might otherwise be exerted upon a pair of conductive wires  51  inserted into LED block  70 . When multiple LED blocks  70  are to be used on a pair of conductive wires  51 , the blocks can be aligned along the pair of conductive wires  51  before LEDs  70  are inserted into each LED block  70 . Because multiple LED blocks  70  can be used on a single pair of conductive wires  51 , a large number of LEDs  70  can be supported by a single electrical assembly. For example, electrical assembly  1  can be used to support a ribbon block assembly  40  that has four pairs of conductive wires  51 , each of which has up to nine (or more) LED blocks  70 , which means the total assembly can support 36 or more LEDs, in a very inexpensive, yet reliable, assembly. 
     After a pair of conductive wires  51  is firmly in place in an LED block  70 , first and second LED leads  61 . 1  and  61 . 2  of an LED  60  are each brought down and inserted into LED lead cavities  72  of LED block  70 . LED lead cavities  72  can be designed to adjust the spacing of LED leads  61 . 1  and  61 . 2  and self-align them for insertion into a pair of conductive wires  51 . Such self-alignment can be accomplished, for example, by forcing LED leads  61 . 1  and  61 . 2  together by narrowing the width of LED lead cavities  72  when the width between LED leads  61 . 1  and  61 . 2  is greater than the width of the pair of conductive wires  51  where they will make contact (see  FIG. 13   a ). Also, if the width of the LED leads  61 . 1  and  61 . 2  is narrower than the width of the pair of conductive wires  51 , then LED lead cavities  72  could be used to force LED leads  61 . 1  and  61 . 2  further apart and into alignment. As noted earlier, each lead  61 . 1  and  61 . 2  has a sharp pin point  62  that facilitates insertion of the leads through insulative covering  52  of conductive wires  51 . Wire hole  71  and LED lead cavities  72 , in an especially preferred embodiment (see  FIG. 13 ), intersect at a right angle. Alternatively, the angle can vary (see  FIGS. 11 and 12 ), or wire hole  71  and LED lead cavities  72  can even meet straight on (see  FIG. 16 ), although such configurations are not preferred. 
     Accordingly, the present invention allows many LEDs to be used in a variety of applications without the need for any solder whatsoever and such construction can be achieved by a simple assembly process that greatly reduces manufacturing cost. This represents a significant advantage over prior art techniques, especially when many LEDs are being combined and electrically connected in parallel on a single pair of conductive wires  51 . 
     So far the present disclosure has disclosed how a number of sub-assemblies can be assembled quickly, simply, and economically without the use of solder. A further embodiment will now be disclosed in which electrical assembly  1  is placed inside of an outer case  100  which can conveniently be constructed of plastic. As illustrated in  FIG. 2 , outer case  100  has case bottom  102  in which electrical assembly  1  is placed and case cover  101  which is then closed complete a sealed case. In an especially preferred embodiment, either case cover  101  or case bottom  102  has one or male members  103  designed to mate with counterpart one or more female members  104  found in its opposite member. The mating of one or more male and female members serves as an alignment guide as well as increasing structural integrity of a sealed case. After electrical assembly  1  is inserted into case bottom  102  and case cover  101  is closed, the case can be sonic welded. Wires  50  extend out of the sealed case, with the case acting both to insulate electrical assembly  1  and also to help insure the structural integrity of ribbon block assembly  40  which is now bent over ninety degrees by closing of case cover  101  and held in place by the sonic welding (see  FIG. 2 ). (It is also further possible that sonic welding can cause insulative covering  52  of conductive wires  51  to weld to the parts of case  100 , thus creating an even stronger bond, and making it less likely for ribbon wire assembly  50  to move in future use.) 
     Accordingly, the present invention discloses a simple, cost-effective electrical assembly and process of manufacture that is environmentally friendly and, in an especially preferred embodiment, well suited for use with LEDs. Moreover, the electrical assembly is compact and sturdy and well suited for use in a variety of applications, including for use in footwear and clothing. 
     Although the foregoing detailed description is illustrative of preferred embodiments of the present invention, it is to be understood that additional embodiments thereof will be obvious to those skilled in the art. For example, it is possible to connect multiple electrical assemblies  1  together so that a single switch assembly  20  triggers multiple chains of LEDs to activate at the same time. Such an assembly will be particularly useful for footwear and other applications where size and cost is important, but it is desired that a large number of LEDs (e.g., twelve), light at the same time. In addition, it is possible that multiple batteries can be aligned next to each other, instead of on top of each other, where there is more concern about vertical height of an assembled unit than horizontal length of the unit. Also, electrical components with multiple leads, instead of LEDs, can be connected to a pair of conductive wires using an electrical component block that applies the principals stated herein to such components. Further modifications are also possible in alternative embodiments without departing from the inventive concept. 
     Accordingly, it will be readily apparent to those skilled in the art that still further changes and modifications in the actual concepts described herein can readily be made without departing from the spirit and scope of the disclosed inventions as defined by the following claims.