Patent Publication Number: US-6991488-B2

Title: Electrical connector devices and methods for employing same

Description:
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/413,362, filed Sep. 25, 2002. 
    
    
     BACKGROUND OF THE INVENTION 
     Magnet wire is a single strand wire is typically used whenever a coil is built, and in a variety of other applications. Typically it is covered by a relatively thin film of insulation, which serves to insulate the wire from adjacent wires. Magnet wire can be very thin, ranging in diameter to 0.010″, if not even thinner. 
     Lead wire is used to convey larger amounts of electricity over longer distances, such as from a power source to a coil. A lead wire is typically a multi-strand conductor for flexibility and is covered by a relatively thick layer of insulation. A standard configuration for lead wire is 10 conductor strands, each measuring 0.010″ diameter, and covered by insulation. The entire lead wire typically has a diameter of about 0.100″. 
     Bare wire is among the most basic of wires. It is merely a single strand conductor with no insulation surrounding it. Bare wire is also used as the lead wire to electronic components. It can also be very thin. 
     Many methods are known to connect wires together. Among these are splicing by solder, splicing by clip; splicing by mechanical clamp, etc. Other known methods employ indirect connection, whereby an intermediary conductive piece is introduced between, and connected to, each wire. 
     Particular examples of the intermediate piece employment can be seen in coils where the plastic bobbin upon which the coil is wound has built-in pockets for receiving insulation displacing connectors. 
     Insulation displacing connectors avoid the necessity of pre-stripping the insulation from the conductors. Instead, the insulation is cut and moved away sufficiently from the connector so that electrical contact is made between the connector and the internal wire conductor. This is often done in one simple stroke. 
     Products supplied by Tyco International called “Magmate,” “Siameze” and “Leadloc” are examples of applications of connecting magnet wire to lead wire. 
     However, these products are designed so that they connect to the magnet wire either before of after connecting to the lead wire. This means that there are multiple operations. Also, the “Leadloc” product contains more than one part. It uses an additional component to retain the lead wire. 
     Also, products such as these are limited in how well they make a mechanical and electrical connection with a wire. They are further limited in this area by the diameter of the wire being connected. The smaller the wire, the lower the probability that an effective, gas tight connection will be made. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide an electrical connector that will establish an effective, gas tight electrical connection between the connector and a wire. 
     It is another object of the present invention to provide an electrical connector that can connect two or more wires in one operation. 
     It is another object of the present invention to provide an electrical connector that connects at least two wires and is configured to retain and entrap said wires without need for an additional retaining component. 
     It is yet another object of the present invention to provide a method for producing an electrical connector that will establish a effective, gas tight electrical connection between the connector and a smaller diameter wire that is superior to connector produced using only die stamping methods. 
     It is still another object of the present invention to provide an electrical connector that will adequately and consistently displace the insulation surrounding the wire to provide an effective, gas tight electrical connection between the connector and a wire. 
     It is yet still another object of the present invention to provide an electrical connector that will aid in the retention of the wire to the connector. 
     It is a further object of the present invention to provide an electrical connector that will aid in the retention of the connector to an outside mounting medium. 
     It is yet a further object of the present invention to provide an electrical connector that will resist deformation and overinsertion into an outside mounting medium. 
     It is also former an object of the present invention to provide a method for minimizing swelling caused by rounding slot walls in an electrical connector of a small dimension using a radius. 
     The present invention provides an electrical connector for connecting two or more wires together electrically, where the wire slots are oriented in a direction substantially parallel to each other. This facilitates the use of only one operation to connect all wires. This significantly improves productivity by reducing the number of operations required to connect wires together, and significantly reduces the cost and amount of capital equipment required for such connection process. The present invention also naturally traps a terminated wire in its slot, thereby eliminating the need for an additional wire termination or a wire staple. This provides a substantial cost reduction. The slots of the present invention can be configured to connect magnet wire to magnet wire, lead wire to lead wire, component lead to magnet wire, component lead to lead wire or other combinations. Also, the present invention contemplate in one embodiment could more than two slots for connecting additional items in a simultaneous manner. 
     The connector of the present invention can be made as part of a continuous strip of material. Indentations can be made to facilitate a scrapless separation of each connector from said strip during application, thereby eliminating the problems of scrap piece control and removal. 
     Further, the present invention also comprises a method for minimizing swelling, and resulting connector distortion, caused by rounding slot walls of the electrical connector to facilitate easy wire insertion and eliminate potentially destructive sharp ends. 
     The present invention also provides specific blade and cavity configurations that allow for the displacement of insulating material from a connected wire, to provide an effective, gas tight mechanical and electrical connection, prevent inadvertent wire removal and prevent distortion of the connector. 
     The present invention also further provides a method of manipulating blades to achieve an effective, gas tight mechanical and electrical connection based upon a spring load; and to allow the slots to accept wire of smaller diameter than has been heretofore economically practicable. 
     The present invention still further provides electrical connectors adapted for attachment to a printed circuit board. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top perspective view of a prior art coil and coil bobbin with lead wires and magnet wires to which the teachings of the present invention may be applied. 
         FIG. 2  is a front perspective view of a first embodiment of an electrical connector of the present invention. 
         FIG. 3  is a front perspective view of a plurality of electrical connectors according to a preferred embodiment of the present invention applied to a coil and coil bobbin with lead wires and magnet wires according to one method of the present invention. 
         FIG. 3A  is a perspective view of an embodiment of performing a method of electrical connector production of the present invention. 
         FIG. 4  is a front view of a second embodiment of an electrical connector of the present invention. 
         FIG. 4A  is a front perspective view of a plurality of electrical connectors according to a second embodiment of the present invention. 
         FIG. 4B  is a front perspective view of another blade embodiment of the second embodiment of an electrical connector of the present invention. 
         FIG. 4C  is a front view of another blade embodiment of the second embodiment of an electrical connector of the present invention. 
         FIG. 4D  is a front view of a further blade embodiment of the second embodiment of an electrical connector of the present invention. 
         FIG. 4E  is a font view of a prior art blade embodiment. 
         FIG. 4F  is a front view of a magnet wire acted upon by a further blade embodiment of the second embodiment of an electrical connector of the present invention. 
         FIG. 4G  is a front view of a magnet wire acted upon by a prior art blade embodiment. 
         FIG. 5  is a top view of an embodiment of performing a method of electrical connector manipulation of the present invention. 
         FIG. 6  is a top view of another embodiment of performing a method of electrical connector manipulation of the present invention. 
         FIGS. 7   a  and  7   b  are front views of a prior art electrical connector applied to a single stand magnet wire and multi-strand lead wire. 
         FIGS. 8   a  and  8   b  are front views of an embodiment of the present invention applied to a single strand magnet wire and multi-strand lead wire. 
         FIG. 9  is a front perspective view of a third embodiment of an electrical connector of the present invention. 
         FIG. 9A  is a front perspective view of a plurality of electrical connectors according to a third embodiment of the present invention. 
         FIG. 10  is a front view of a fifth embodiment of an electrical connector of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       FIG. 1  is a representation of a simple coil  10  wound on a bobbin  20 . Bobbin  20  further comprises integrated pockets  22  and slots  24 . The ends  32  of the magnet wire  30  winding are pre-positioned and anchored in their appropriate slots  24 . The ends  42  of the lead wires  40  are also pre-positioned in their slots  24 . Slots  24  hold the wires in exact positions across pockets  22 . Pockets  22  are adapted to support the wires while a connector  100  is introduced into them, as illustrated in FIG.  3 . 
     Electrical connector  100  is preferably a planar piece of conductive material, usually metal. Now referring to  FIG. 2 , a preferred embodiment of a metal connector  100  is disclosed, typically produced by progressive die stamping, as is known in the prior art. Slot  110  is configured to accommodate magnet wire  115  and slot  140  is configured to accommodate lead wire  145 . Slot  110  comprises a small cantilever blade  120 , which keeps a spring load on magnet wire  115  as the slot slides across the magnet wire  115 . The sliding action cuts and abrades away the film of insulation surrounding the magnet wire, allowing a gas tight, spring loaded contact of wire  115  between the slot edge  111  of slot  110  and opposing blade edge  121  of blade  120 . Blade  120  is preferably manipulated into this cantilever configuration by the method described below. Blade  120  is initially stamped in a position remote of slot edge  111 . It is manipulated toward the slot edge  111  of slot  110  such that it becomes an unloaded spring, at rest adjacent to slot edge  111 . When magnet wire  115  is inserted between blade edge  121  and the slot edge  111 , the force from the insertion serves to spring load the blade, which in turn places fore upon magnet wire  115 . This helps to displace the insulation from magnet wire  115  and to maintain an effective, gas tight mechanical and electrical contact between the edges and the wire. 
     At the same time, lead wire slot  140 , via blades  150 , cuts and spreads the insulation of lead wire  145  and allows penetration, a gas tight contact and squeeze of the outer strands of lead wire  145  conductor. Cavity  160  provides an area where the displaced insulation from lead wire  145  can collect when the lead wire is inserted into slot  140 . This configuration reduces the force that bunched up insulation would place on lead wire  145  to move toward the open end of slot  140 , helping to prevent inadvertent removal of the lead wire  145  from slot  140 . This configuration also reduces the force that bunched up insulation would place on connector  100  itself, which could contribute to distortion of the configuration of connector  100 . 
     In a preferred embodiment, connector  100  further comprises wedges  170  and  180 . In this embodiment, wedges  170  and  180  are oriented between the ends  198  and  199  of connector  100  toward the end  199  adjacent to slots  110  and  140 . Wedges  170  and  180  provide mechanical catches or stops to prevent overinsertion of connector  100  into its mounting medium, preventing deformation of end  199  of the connector  100  adjacent to slots  110  and  140 . Wedges  170  and  180  also provide added stability to the remainder of connector  100 , acting to prevent slippage and inadvertent removal of connector  100  by mechanically catching the mounting medium and adding surface area that is in contact with the mounting medium, increasing friction between the medium and the connector. 
     Now referring to  FIG. 3 , a preferred embodiment of a method for providing a plurality of connectors is disclosed, said plurality of connectors joined top to bottom, into a continuous strip  1100 . The separation of connectors  100  of the strip  1100  can be achieved without producing any scrap “knock outs,” that is pieces of material between each individual connector  100 . In a preferred embodiment, connectors  100  are die stamped from blank material  1150  on a rolling die press  1200 , as illustrated in FIG.  3 A. Rolling die press  1200  has a rotary die  1210 , which is comprised of multiple individual dies  1220  in the configuration of connectors  100 , arranged top to bottom around the circumference of the rotary die  1210 . Between the top and bottom of each of these individual dies  1220 , is located a thin indentation  1230 . The blank material  1150  is fed into rolling die press  1200 . Rotary die  1210  repeatedly stamps connector  100  and a slight indentation  1250  into the material. This creates scrap material in the various cavities of the connectors  100 , but does not create any scrap material between the connectors  100 . The resulting stamped material is strip  1100 . Strip  1100  can be stored in high capacity reels. 
     Now referring to  FIG. 3 , a preferred embodiment of a method of high volume automatic assembly of connectors  100  into bobbins  20  is disclosed. Strips  1100  of connectors  100  are fed from high capacity reels into slots  24  of bobbins  20  containing magnet wires  30  and lead wires  40 . This causes connector  100  to electrically engage and connect magnet wires  30  and lead wires  40 . The individual connectors  100  are then snapped off at indentations  1250 . The completed bobbin  20  with wire connector  100  is then removed and the process is repeated. 
     For very low volume, such as prototype or pilot production, the individual connector  100  can be neatly applied using the following preferred embodiment of the present invention. Each connector  100  in strip  1100  is simply snapped off at indentation  1250  and applied using hand pliers positioning and hand press technique. 
     Referring to  FIGS. 2 and 3 , a preferred embodiment of a method placing magnet wire  115  and lead wire  145  into connector  100  in one operation is disclosed. Magnet wire  115  and lead wire  145  are held in place, by a bobbin in the embodiment of  FIG. 3 , substantially parallel to each other and spaced apart substantially the same distance that the centerlines of slots  110  and  140  are spaced. Connector  100 , aligned such that slots  110  and  140  are facing magnet wire  115  and lead wire  145 , is then simply pushed onto magnet wire  115  and lead wire  145  until magnet wire  115  is positioned snugly in slot  110  and lead wire  145  is positioned snugly in slot  140 , such that the insulation of magnet wire  115  and lead wire  145  is removed and both wires are in electrical contact with connector  100 . 
       FIG. 4  illustrates yet another embodiment of the present invention wherein slots  210  and  220  are oriented in a direction substantially parallel and opposite to each other. Electrical connector  200  is a planar piece of conductive material, usually metal. Slot  210  is configured to accommodate a braided (stranded) lead wire that is insulated. Tang  220  protrudes from a closed end of slot  210  toward the open end of slot  210 . Tangs  220  are sharp-edged and pointed to pierce the insulation of the lead wire. Now referring also to  FIG. 8 , this configuration also facilitates tangs  220  sliding in between the strands of the lead wire, providing an effective, gas tight electrical connection between connector  210  and the lead wire. Hook  230  is a protrusion from the lateral wall  221  of slot  210 . It acts to retain the lead wire by mechanically catching the insulation of a lead wire in a fashion similar to a barbed fishing hook, allowing the insertion of the lead wire into slot  210  but catching it if removal of the same is attempted. Cavities  232  provide areas where the displaced insulation from the lead wire can collect when the lead wire is inserted into slot  210 . This provides two advantages. It reduces the force that bunched up insulation would place on the lead wire to move toward the open end of slot  210  helping to prevent inadvertent removal of the lead wire from slot  210  It also reduces the force that bunched up insulation would place on connector  200  itself, which could contribute to distortion of the configuration of connector  200 . 
     Slot  240  is configured to accommodate a magnet wire that is insulated. Blades  250  protrude from the lateral edges of slot  240  towards its closed end. Blades  250  are configured such that they approach each other and a centerline of slot  240 , between the lateral edges  201  of connector  200 . Blades  250  are manipulated into this configuration by the method described below. Blades  250  are initially stamped in a position remote of each other. They are manipulated toward blade lateral edges  252  of each other such that they become unloaded springs, at rest adjacent to each other. When magnet wire  222  is inserted between blade lateral edges  252 , as illustrated in  FIG. 8 , the force from the insertion eves to spring load blades  250 , which in turn places force upon magnet wire  750 . This helps to displace the insulation from magnet wire  750  and to maintain an effective, gas tight mechanical and electrical contact between the edges  252  and wire  750 . Edges  252  may also cut into the strand, providing added strength to the connection. 
     Each lateral edge  201  of connector  200  preferably further contains an indentation  270 . The indentation  270  in a preferred embodiment further comprises hook  280 . Indentation  270  and hook  280  provide an area for engaging connector  200  with a mounting medium, such as a plastic housing or a plastic bracket mounted on a printed circuit board such as those known in the art. Hook  280  provides two advantages in the mounting function. It provides a mechanical catch or stop to prevent overinsertion of connector  200  into its mounting medium, preventing deformation of the end of the connector adjacent to slot  240 . Hook  280  also engages the mounting medium, especially where the mounting medium is constructed of plastic or another malleable material. This engagement stabilizes the lateral edge  201  of the connector, further preventing deformation of connector  200 . 
     Connector  200  further preferably comprises wedges  290 . In this embodiment, wedges  290  are aligned from the centerline of connector  200 , between ends  298  and  299 , toward end  299  adjacent to slot  240 . Wedge  290  provides a mechanical catch or stop to prevent overinsertion of connector  200  into its mounting medium, preventing deformation of the end  299  of connector  200  adjacent to slot  240 . Wedge  290  also provides added stability to the remainder of connector  200  and further acts to prevent slippage and inadvertent removal of connector  200  by mechanically catching the mounting medium and adding surface area that is in contact with the mounting medium, increasing friction between the medium and the connector. 
     Now referring to  FIG. 4A , a preferred embodiment of a method for providing a plurality of connectors  200  is disclosed, said plurality of connectors joined wing to wing, into a continuous strip  2100 . The separation of connectors  200  of the strip  2100  can be done along indentation  2250  without producing any scrap “knock outs,” that is pieces of material between each individual connector  2100 . The method of producing a plurality of connectors illustrated in  FIG. 3A  can be adapted to produce a plurality of connectors  200 . 
     Referring to FIGS.  4  and  8 ( a ), a preferred embodiment of a method placing magnet wire  750  and lead wire  720  into connector  200  is disclosed. Magnet wire  720  and lead wire  750  are held in place, substantially parallel to each other and spaced apart a distance greater than the length of lateral edge  201  of connector  200 . Connector  200  is aligned along the shared centerline of both slots  210  and  240 , such that slot  240  is facing magnet wire  750  and slot  210  is facing lead wire  720 . Magnet wire  750  and lead wire  720  are then simply pushed together onto connector  200  until magnet wire  750  is positioned snugly in slot  240  and lead wire  720  is positioned snugly in slot  210  such that the insulation of magnet wire  750  and lead wire  720  is removed and both wires are in electrical contact with connector  200 . 
       FIGS. 4B and 4C  illustrates an embodiment of connector  200 , further comprising blades  250  having sharp notches  251 . Notches  251  engage insulation  751  of magnet wire  750  when it is inserted into slot  240  and cut through and peel insulation  751  such that blades  250  can electrically connect with conductor  752  of magnet wire  750 . 
       FIGS. 7   a,    7   b,    8   a  and  8   b  illustrate some of the advantages provided by the present invention over the prior art.  FIGS. 7   a  and  7   b  show a prior art electrical connector  700  for connecting multi-strand lead wire  720  and single strand magnet wire  750 . The lead wire  720  stands are bunched together and distort the edge of the connector slot. This results in a relatively poor connection and in little friction between the slot edges and lead wire  720 . Meanwhile, the insulation of lead wire  720  bunches up and has no place to go. This results in the insulation pushing lead wire  720  toward the open end of the slot, which leads to the inadvertent removal of the lead wire  720 . 
     Regarding single strand magnet wire  750 ,  FIG. 7   a  shows the magnet wire connected by the prior art connector in a typical manner. However,  FIG. 7   b  shows a poor connection between the magnet wire  750  and the connector, resulting from distortion in the connector  700  and less than desirable tolerances in the dimensions of the blades connected to the magnet wire. 
       FIGS. 8   a  and  8   b  illustrate an embodiment of the present invention configured to connect lead multi-strand lead wire and single strand magnet wire.  FIG. 8   a  shows the connection between the strands of the lead wire  720  and tangs  220  of the connector  200 . Tangs  220  slide in between the strands of the lead wire, providing a large surface area to establish effective, gas tight electrical and mechanical (frictional) contact. Connector  200  including tangs  220  is also appropriate for use with a solid lead wire, wherein the solid lead wire is fittingly placed between tangs  220  (not illustrated). Cavities  232  allow the insulation of the lead wire  720  to collect without applying outward pressure on lead wire  720 , thus preventing inadvertent removal. Hooks  230  provide further impediments to inadvertent wire removal by grasping into the insulation of lead wire  720  when the wire is forced outward, acting like a barbed fishing hook. 
       FIG. 8   b  shows the connection between the connector and the magnet wire  750 , via blades  250 . Thanks to the manipulation of blades  250  using the methods described below, the connection between blades  250 , via blade lateral edges  252 , and magnet wire  750  is a more effective, gas tight and precise mechanical and electrical connection based upon a spring load, especially when smaller diameter wire is used, than has been heretofore economically practicable. 
       FIG. 4D  illustrates a further embodiment of connector  200 , further comprising lades  250  having blade lateral edges  252  containing rounded edges.  FIG. 4D  shows a cross-sectional view of blade  250 , through a line A—A, and includes magnet wire  750  placed between lateral edges  252 . Magnet wire  750  comprises insulation  751  and conductor  752 . 
       FIG. 4E  illustrates a prior art blade configuration  5000  having pointed blade edges  5001 . This configuration contains the drawback of cutting deeply into conductor  752 . This results in a weakening of magnet wire  750   FIG. 4G  shows conductor  752  after it has been connected to a prior art blade configuration. Conductor  752  is deeply notched and is substantially weakened structurally. 
     Referring back to  FIG. 4D  in the present embodiment rounded edges  252  prevent blades  250  from substantially cutting into conductor  752 .  FIG. 4F  shows magnet wire  750  after it has been connected to the blades of the present embodiment. Conductor  752  is only lightly abraded and maintains its structural strength. 
       FIG. 9  illustrates still another embodiment of an electrical connector of present invention and demonstrates how the conductors connected using the present invention are not limited to wires. Connector  600  is adapted to connect a lead wire with a printed circuit board (PCB). Electrical connector  600  is a piece of conductive material, usually metal. Wire portion  610 , comprising slot  240 , blades  250  and cavities  260 , is adapted to mechanically and electrically connect to a lead wire in a manner similar to that of the connector illustrated in FIGS.  4  and  8 ( a ), described in depth above. PCB portion  620  is adapted to mechanically and electrically connect to connection holes in a printed circuit board, which is known in the prior art. Prongs  630  are configured a dimension to snugly fit into the holes of a printed circuit board. 
     Now referring to  FIG. 9A , a preferred embodiment of a method for providing a plurality of connectors  600  is disclosed, said plurality of connectors joined wing to wing, into a continuous strip  3100 . In this embodiment, connectors  600  are adapted to connect a lead wire to a PCB hole, similar to the embodiments of connector  600  in FIGS.  9 A. The separation of connectors  600  of the strip  3100  can be done along indentation  3250  without producing any scrap “knock outs,” that is pieces of material between each individual connector  3100 . The method of producing a plurality of connectors illustrated in  FIG. 3A  can be adapted to produce a plurality of connectors  600 . 
       FIG. 10  illustrates a further embodiment of those electrical connector embodiments of the present invention that are adapted to accommodate a lead wire,  FIGS. 4 ,  8 ( a ). Wings  291  are each loosely defined by slot  210 , cavity  232  and adjacent lateral edge  281 . Lead wire  720  is positioned snugly into slot  210  such that its insulation is removed and it is in electrical contact with connector  200 . Then, wings  291  are bent around lead wire  720  positioned in slot  210 , creating a door-like stop for retaining and entrapping lead wire  720  and preventing its inadvertent removal. 
     Method of Manipulating Blade 
     Traditionally, electrical connectors in the art of the present invention have been manufactured by die stamping them from a sheet of conductive material. 
     As shown in  FIG. 5 , connector  300  comprises blades  310  for mechanically and electrically connecting to a magnet wire of very small diameter, 0.010″ for instance. Connector  300  is stamped out of the material sheet in the configuration as shown, providing elements including blades  310 , and cavities  320  adjacent to each blade  310 . Under conventional stamping techniques, blades  310  can only be stamped to a certain small dimension and a certain distance from an opposing blade or a slot wall, depending upon variables such as stamping equipment and material used. Stamping any smaller or any closer than the variables allow, results in broken or weak blades that will not function properly. The present invention solves this problem by stamping blades remote from each other and then manipulating them into a desired configuration using a tool. 
     According to one preferred embodiment a method is provided is provided wherein connector  300  is positioned about tool  400 , with tool  400  positioned within cavity  320 . Tool  400  is mounted on a movable base  410 . Tool  400  is then moved against blade  310  by movable base  410 . Movable base continues to move tool  400  and blade  310  until blade  310  is manipulated into the desired position. Connector  400  is then removed from tool  400 . The process may be repeated on further blades of the connector. Movable base  400  may move in any desired direction, including arching, linear (see  FIG. 6 ) or a more complex motion. In an alternate embodiment, this method may be employed such that the connector  300  is moved about a fixed tool  400  to manipulate blade  310 , instead of tool  400  being moved via movable base  410 . 
     This method can be applied to the blades of any electrical connector where extremely small close tolerances are necessary to facilitate proper connection to wires of very small diameters. This includes blades  120  of connector  100 , using cavity  130 ; and blades  250  of connector  200  using cavities  260 . 
     In the following, the patent claims will be given, and the various details of the invention can show variation within the scope of the inventive idea defined in the claims and differ even to a considerable extent from the details stated above by way of example only. As such, the examples provided above are not meant to be exclusive and many other variations of the present invention would be obvious to those skilled in the art, and are contemplated to be within the scope of the appended claims.