Patent Publication Number: US-8979553-B2

Title: Connector guide for orienting wires for termination

Description:
BACKGROUND OF THE PRESENT DISCLOSURE 
     The Present Disclosure relates generally to plug connectors, and more particularly to plug connectors with an improved wire termination aspect. The technology industry is ever growing and the need for more technology infrastructure, such as more routers and servers, exists in order to utilize internet access to its full capability. 
     Routers and servers and storage machines are interconnected by high speed connector assemblies in the form of cables having connectors, typically plug connectors, which are terminated to their ends. These connectors are designed for high speed data transmission and typically include a cable that holds a plurality of pairs of twin-axial wires. Twin-axial wires have two signal transmission wires that cooperatively transmit differential signals. A ground or drain wire is associated with each such pair and the twin-axial wires and a drain wire comprise each such signal transmission pair. The twin-axial wires are small and fragile and must be separated from the cable, termed “breakout” in preparation for termination. Care must be taken during termination of the twin-axial wires to the connectors so as not to bend, and consequently break the wires. 
     Furthermore, it is common to have the inner wires of the cable extend along a preselected length during termination which is unsupported. This requires the use of a jig specifically configured to provide support for the wires and to hold them in a desired orientation for their termination to the edge card of the connector. The need for specialized equipment also increases the cost of the connector and even with the jig, the wires are terminated to the edge card in an unsupported state and then a supporting plastic or other moldable material is injected around them and portions of the paddle card, after the termination of the cable wire pairs to the edge card. Hence, there presently appears not to be any reliable way of orienting and supporting the cable wires in a desirable orientation prior to the termination thereof to the connector edge card. 
     The Present Disclosure is directed to a structure that solves the aforementioned problems by providing a means to orient the cable wires, in sets or pairs in a generally horizontal orientation for termination to an edge card and for supporting the wires during termination in a manner so as to reduce the likelihood of damage to the wires of the wire joints as the wire conductors are soldered to the edge card. 
     SUMMARY OF THE PRESENT DISCLOSURE 
     In one aspect, the Present Disclosure describes a guide member that orients the cable wire pairs from a vertical orientation to a horizontal orientation where the signal wires of the sets are arranged in a generally horizontal pattern and are fixed in place to provided strain relief to the wires during the termination thereof. In another aspect, the guide member includes structure that captures the wires and supports them in a reliable and steady orientation so as to provide a discrete mass enclosing portions of the wires that may be easily manipulated during attachment of the wires to the edge card and that facilitates handling of the breakout portion of the cable. 
     A guide member in accordance with the principles of the Present Disclosure includes a body portion that is formed of two halves. The halves are preferably interengaging elements that have at least two wire paths that are cooperatively defined when the halves are assembled together. The wire paths are twisted in their orientation, meaning they are aligned together with a first axis at one end of thereof and they are aligned together with a second axis, different than the first axis at the other end thereof. The interior walls of the guide member parts are fashioned so that the guide member parts may be placed into a holder and a cable wire pair inserted therein and pushed therethrough. As the cable wire pairs travel the length of the wire paths, they contact the walls of the wire paths and are twisted in their orientation so that the free ends of the wire pairs are oriented along the second axis. 
     The wire pairs have twisting walls that serve to re-orient the wire pairs from a generally vertical (first) orientation to a generally horizontal (second) orientation. In order to ensure the integrity of the guide member, the guide member, the guide member halves are preferably provided with a plurality of ports that mate together and which provide injection points into which a settable material is injected. The material of choice, at present, is a hot melt adhesive which can be injected at low pressures to reduce any likelihood that crushing of the cable wire pairs will result. Alternatively, the guide member halves may be riveted, screwed, press-fit or welded together, or combined in any other fashion. One port at least communicates with the interior of the guide members, and specifically the wire paths thereof and defines a pathway through the guide member which the molding material may spread through the guide member into contact with the guide member and the cable wire pairs to form a unitary structure once the hot melt adhesive has set. The other port preferably has a non-uniform configuration that serves to define a locking plug of hot melt and which also communicates with the one port so that the hot melt need only be injected into the guide member at the one port. 
     The guide member preferably has a length that extends from the breakout of the cable free end to just adjacent the tail end of the edge card so that the cable wire pairs are fully supported in that specific extent. The wires of the cable pairs are thus oriented generally horizontally at their forward ends with the guide member in place, and can be more easily applied to contact pads on the edge card and soldered thereto without the twisting and bending that accompanied the cable wires as terminated in the prior art. The unitary guide member provides a measure of stress relief to the cable wire pairs and can easily be molded with an exterior configuration that facilitates its insertion into a connector housing. 
     These and other objects, features and advantages of the Present Disclosure will be clearly understood through a consideration of the following detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The organization and manner of the structure and operation of the Present Disclosure, together with further objects and advantages thereof, may best be understood by reference to the following Detailed Description, taken in connection with the accompanying Figures, wherein like reference numerals identify like elements, and in which: 
         FIG. 1  is a perspective view of a plug connector incorporating the principles of the Present Disclosure; 
         FIG. 2A  is an exploded view of the plug connector of  FIG. 1 ; 
         FIG. 2B  is the same view as  FIG. 2A  but taken from the bottom side thereof to illustrate the other side of connector paddle card and the cable wires terminated thereto; 
         FIG. 3A  is a top, perspective view of the cable of the plug connector of  FIG. 1 , with its inner twin-axial wires held in place by a guide member of the Present Disclosure; 
         FIG. 3B  is the same view as  FIG. 3A  but inverted so as to illustrate the bottom of the guide member; 
         FIG. 4A  is an exploded view of the cable end breakout and the guide member, similar to  FIG. 3A ; 
         FIG. 4B  is a perspective view of a guide member formed in accordance with the principles of the Present Disclosure and utilized in the connector assembly illustrated in  FIG. 2A ; 
         FIG. 4C  is the same view as  FIG. 4B , but illustrating the underside thereof; 
         FIG. 4D  is a top plane view of the guide member of  FIG. 4A ; 
         FIG. 4E  is a side elevational view of the guide member of  FIG. 4D ; 
         FIG. 4F  is a bottom plane view of the guide member of  FIG. 4A ; 
         FIG. 5  is a side elevational view of the cable and guide member attached thereto in the breakout area as illustrated in  FIG. 3A ; 
         FIG. 6  is a bottom plan view of the cable breakout assembly illustrated in in  FIG. 5 ; 
         FIG. 6A  is a longitudinal cross-sectional view of the guide member portion of the cable breakout assembly of  FIG. 6 , taken along Lines Y-Y thereof; 
         FIG. 6B  is a transverse cross-sectional view of the guide member portion of the cable breakout assembly of  FIG. 6 , taken along Lines W-W thereof; and 
         FIG. 6C  is a transverse cross-sectional view of the guide member portion of the cable breakout assembly of  FIG. 6 , taken along Lines X-X thereof 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     While the Present Disclosure may be susceptible to embodiment in different forms, there is shown in the Figures, and will be described herein in detail, specific embodiments, with the understanding that the Present Disclosure is to be considered an exemplification of the principles of the Present Disclosure, and is not intended to limit the Present Disclosure to that as illustrated. 
     As such, references to a feature or aspect are intended to describe a feature or aspect of an example of the Present Disclosure, not to imply that every embodiment thereof must have the described feature or aspect. Furthermore, it should be noted that the description illustrates a number of features. While certain features have been combined together to illustrate potential system designs, those features may also be used in other combinations not expressly disclosed. Thus, the depicted combinations are not intended to be limiting, unless otherwise noted. 
     In the embodiments illustrated in the Figures, representations of directions such as up, down, left, right, front and rear, used for explaining the structure and movement of the various elements of the Present Disclosure, are not absolute, but relative. These representations are appropriate when the elements are in the position shown in the Figures. If the description of the position of the elements changes, however, these representations are to be changed accordingly. 
       FIG. 1  is a perspective view of a plug connector assembly  20  constructed in accordance with the principles of the Present Disclosure. The connector assembly  20  include a multi-wire cable  22  that is terminated to a plug connector  24 , which has a mating blade  26  defined by a circuit card  28  that has an array of contacts, or contact pads,  30  that are arranged along a forward, mating edge  29  thereof. The plug connector  24  has an exterior housing  31  that is configured to be received within a receptacle of an electronic device (not shown). The housing may be assembled from two halves  31   a ,  31   b  as shown or it may be formed as a unitary member. The housing  31  has a hollow interior  32  that receives the open end of the cable  22  as well as the circuit card  28 , which may be supported therein on shoulders  33  defined within the housing  31  and along the inner sides of the housing halves  31   a ,  31   b.    
     The housing  31  may further be provided with a latching assembly  35  that selectively engages and disengages the electronic device to which it is mated. The latching assembly may include, as illustrated best in  FIG. 2A , a moveable latching member  36  that is received within a cavity  37  of the housing  31 . An actuator  38  is provided that fits over the cable  22  by way of a loop  39  and has a finger loop  40  by which a user can grasp the actuator  38  and pull on it in order to disengage the latch member  36  from the device. A metal shielding collar  42  is also present on the exterior of the plug connector  24  to provide EMI shielding at the location where the plug connector will meet the opening of the receptacle of the electronic device. 
     The circuit card  28  includes circuits that extend between the opposite ends of the card  28  and which are terminated to contact pads. Such a circuit card  28  is referred to in the art as either an edge card or a paddle card and those two terms are used in this description interchangeably. The forward contact pads  30  are ones that make contact with opposing electrical contacts of a receptacle connector of the electronic device while the rear contact pads  29  are located rearwardly of the front contact pads  30  and may or may not be disposed proximate the rear edge  45  of the paddle card  28 . The rear contact pads  29  provide termination locations for the cable wire pair conductors  54 . The cable  22  has an exterior, insulative housing  50  that encloses a plurality of wires which are arranged in sets  51  that comprise two signal transmission wires  52  and a ground, or drain wire  53  such that the sets, or pairs, define signal transmission lines that are suitable for transmitting differential signals. Each such wire set comprises a wire pair  51 , which is known in the art as a twin-axial cable, or pair. The wire pairs  51  each include two signal wires  52  and an associated ground or drain wire  52 . The signal wires may be separately formed with center conductors  54  enclosed within separate, associated insulative coverings  55 , or the two conductors  55  of each wire pair  51  may be enclosed within a single insulative covering. The drain wire  53  may or may not be covered with an insulative coating. Most commonly, it is not. 
     The wire pairs  51  are enclosed within an outer grounding sheath  56  which may be a braided, hollow sheath or a copper foil tube. Typically, these twin-axial wire pairs  51  are arranged in a vertical orientation with in the cable  22 . In order to terminate the signal and drain wires to the paddle card  28 , a “breakout” is formed, meaning the cable  22  is cut to form a free end, and the cable grounding sheath  56  is pulled back over a certain length of the cable free end for contacting the plug connector housing  31 . This cable breakout is shown, for example, in  FIG. 4A . The cable outer insulative covering  50  is cut back so as to expose a preselected length L of the wire pairs  51  and drain wires  53 . These signal and drain wires  52 ,  53  are small and fragile and are susceptible to breaking under excessive and/or rough handling. These wires  52 ,  53  are often bent when handled and the ends are easily stubbed and or broken. Additionally there is an intervening space  44  through which the wire pairs  51  extend between the breakout from the cable  22  and the tail end  45  of the paddle card  28 . The plug connector assemblies  20  are subject, at times, to repeated insertion and removal from their associated devices. With such movement, comes repeated bending in this intervening area  44 , thereby putting stress on the wire pairs  51  and the soldered joints that attach the conductors of the signal and drain wires  52 ,  53  to the paddle card  28 . 
     The Present Disclosure is directed to a solution to this problem that reinforces the breakout area and which aligns the wires at minimal cost in both material and labor. A guide member  60  in accordance with the Present Disclosure is shown in  FIG. 2B  as extending in the space  44  between the breakout end, that is, the free end of the cable where the inner wire pairs  51  are exposed, and the tail end  45  of the paddle card  28 . Normally this area remains open or is filled with a solid material after the termination of the cable wire pairs  51  to the paddle card contact pads  29 . In the Present Disclosure, the guide member  60 , as illustrated in  FIGS. 3A and 3B  is applied to the exposed portions of the cable wire pairs  51  and forms a unitary structure that holds the cable wire pairs in a preferred orientation, i.e, generally horizontally, and which provides a solid block that may be held either manually or as within a jig to hold the cable pair wire ends in place for attachment to the paddle card  28 , such as by soldering. 
     The guide member  60 , as shown best in  FIG. 4A , is preferably formed from two parts  60   a ,  60   b  that mate together. It is preferred that the two parts interengage each other utilizing structure known in the art such as posts  61  and complementary-shaped holes  62  ( FIG. 4C .) The two guide member parts, or halves  60   a ,  60   b  have a plurality of hollow guide paths  63  defined therein that extend lengthwise between the opposite ends  64   a ,  64   b  of the guide member  70 . Each of these guide paths is configured to receive a single twin-axial wire pair  51  from the cable  22  in a manner such that the wire pair  51  may be inserted from one end, the rear, or tail end  65   b  as shown in  FIGS. 3A &amp; 3B  and pushed through the guide member  60  so that the free end of the wire pair  51  exits the other, or front end  65   a , of the guide member  60 . 
     The wire pairs  51  of the cable  22  have a generally vertical orientation at the cable breakout area and as such, are preferably aligned with each other on opposite sides of an intervening vertical axis ( FIG. 6B .) The guide paths  63  are not linear but, rather, are twisted, or what may be considered as defining a torturous path through the guide member  60  so that the orientation of the wire pairs  51  are changed from one end of the guide member  60  to the other end. This change, as shown in the drawings, is from the general vertical orientation at the tail end  65   b  of the guide member  60  to a generally horizontal orientation at the forward, or leading end,  65   a  of the guide member  60 . This orientation change also may be considered as a rotation of the wire pairs aorund a longitudinal axis thereof. Such rotation is approximately 90 degrees (plus or minus 10 degrees for tolerance) so that the wire pairs  51  are arranged in generally horizontally alignment as they exit the guide member  60 . In this manner, the wire pairs may be easily manipulated into place in contact with the paddle card rear contact pads  29  by grasping the guide member either manually or with a device. 
     In order to maintain the impedance of the wire pairs  51  at a desired level, the guide paths  63  are preferably mirror images of each other, or are symmetrical with respect to an intervening longitudinal axis G-G, as shown best in  FIG. 4F . In this manner, the conductors  54  of each wire pair  51  are maintained at approximately a desired spacing. As the wire pairs  51  enter the guide member guide paths  63  at the guide member tail end  65   b  they are horizontally oriented at a given center-to-center spacing S 1  and as they are twisted into a horizontal orientation at the guide member front end  65   a , the spacing increases to S 2  ( FIG. 4F .) This increase in spacing is approximately uniform between the wire pairs, which serves to maintain the reduction in capacitance between the wire pairs  52  which occurs as the intervening spacing increases at a constant rate, equal to the degree of turn that occurs in the wire per unit length of the guide member. Without this symmetry, the change in impedance between the two wire pairs would be non-uniform and erratic and subject to inducing interference during high speed data transmission. 
     In order to hold the guide member halves, or parts  60   a ,  60   b , one or more injection opening, or ports  66 ,  67  are provided. One such port  66  is generally circular in configuration while the other port  67  is non-circular and is illustrated in the Drawings as having a keyhole configuration. Both ports  66 ,  67  have cavities that are configured to have larger end portions  68   a ,  68   b  than the intermediate portion  69  that interconnects the ends so that when a settable material is injected into the ports, one or more retaining plugs  70  are formed. In the Drawings, particularly  FIG. 6A , the plug  70  is seen to extend through both ports  66 ,  67  and has two intermediate sections  68  are formed that are interconnected to the larger end portions  70   a ,  70   b . This plug serves to hold the guide member halves  60   a ,  60   b  together. The wire guide paths  63  are slightly larger than the wire pairs  51  which they accommodate and at least one fo the ports communicates with the guide paths  63  in manner such that when the hot melt is injected into the guide member  60 , the hot melt also flows into the guide paths and into contact with the walls thereof and the wire pairs  51 . This enlargement is easily accomplished by chamfering the sidewalls of the port as shown at  72  in  FIG. 4B . 
     This construction forms a unitary structure that can be more easily handled and manipulated, and which reduces the likelihood of bending or breaking the signal and drain wires or their respective conductors. The exterior configuration of the guide member may be chosen so that it is complementary to the interior  32  of the connector  24  so as to facilitate the insertion of it and the attached paddle card  28  into the connector housing  31 . Also, the guide member guide paths  63  may change their elevation relative to the opposite ends of the guide member  60  as the wire guide paths  63  traverse the guide member  60  from end to end  65   a ,  65   b . As shown in  FIG. 5 , this creates a space  74  beneath the wire pairs  51  in their exiting horizontal orientation which can accommodate a portion of the paddle card therein ( FIG. 2B .) 
     While a preferred embodiment of the Present Disclosure is shown and described, it is envisioned that those skilled in the art may devise various modifications without departing from the spirit and scope of the foregoing Description and the appended Claims.