Patent Document

CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of priority to U.S. Provisional Application Ser. No. 61/034,218 entitled “WIRE ORGANIZER” filed Mar. 6, 2008 by David M. Garrison et al, which is incorporated by reference herein. 
     
    
     BACKGROUND 
       [0002]    1. Technical Field 
         [0003]    The present disclosure relates generally to a wire organizer for separating and restraining wires routed through an electronic device. In particular, the present disclosure relates to a wire organizer adapted to permit pre-positioning of discrete wires for use in an over-molded electrical junction assembly. 
         [0004]    2. Background of Related Art 
         [0005]    Wiring for electronic devices such as instruments found in the surgical arts requires organization, for example, to promote efficient manufacturing and maintenance. The various electronic components found in these instruments include circuit boards and power connectors that often involve many discrete and closely spaced contacts facilitating electrical communication with other components. A component may receive inputs at these contacts through wires routed from any number of sources and similarly provide outputs to any number of destinations. When several wires are required to be routed through an instrument along a similar path, an electrical cable is often used to maintain a grouping of the wires. 
         [0006]    An electrical cable typically consists of a core of discrete wires and a dielectric sheath or jacket covering and protecting the core. Each discrete wire includes a conductor for transmitting an electrical potential and may also include an insulation layer for electrically isolating the conductor from other conductors in the cable. In a round cable, the discrete wires may be arranged in a radial pattern such that the cable takes on a circular cross section. In contrast, conductors in a flat cable or flexible circuit are often arranged in a side-by-side relationship. It is often necessary to connect the conductors in a round cable to contacts arranged in a side-by-side relationship. Also, it is often convenient to complete such a connection at a point in the manufacturing process well after the cable and flexible circuit are assembled. 
         [0007]    One such instance is in the manufacturing of a surgical instrument such as the endoscopic forceps described in U.S. patent application Ser. No. 11/540,335 by Patrick L. Dumbauld. In this particular application, several discrete signal wires emerging from the dielectric sheath of a round cable are electrically coupled to side-by-side solder terminals extending from a flexible circuit. One solder terminal is reserved for connection to a wire more conveniently routed outside the cable, while several power wires routed inside the cable must be re-directed away from the solder terminals almost immediately after exiting the dielectric sheath. In this relatively complex environment for an electrical junction, several process failures may occur. These include wire pinching, crushing, partial wire encapsulation, and leak path creation through an over-mold intended to protect the connection. 
       SUMMARY 
       [0008]    The present disclosure describes an electrical wire organizer for facilitating the connection of discrete wires in an electrical cable to a series of electrical contacts arranged in a closely spaced relation to one another. The wire organizer may include one or both of a cable cuff for restraining the cable, and a wire comb having wire receiving channels open to opposite faces. Each wire receiving channel is dimensioned to accept a wire and form friction fit with an insulation layer thereof. At least one of the wire receiving channels may be enlarged to accept a larger gauge wire than the others. Each of the wire receiving channels may be open to a peripheral side of the wire comb to allow a wire to be pressed laterally into place. A reduced width portion may be included in such a wire receiving channel to restrain the wire once it is pressed into place and tapered entry surfaces may ease the insertion of the wires. 
         [0009]    The cable cuff may include a cable reception cavity and a wire reception cavity such that the cable cuff may restrain wires against the jacket of a cable. The cable cuff may be pressed laterally onto a cable and may be held in place by a friction fit with the cable jacket. 
         [0010]    In one embodiment, the wire organizer includes a cable cuff and a wire comb coupled to one another by a bridge establishing an axial separation between the two components. In such a one-piece embodiment, a friction fit with only one of the wire comb and cable cuff may secure the axial position of the wire organizer. Such a wire organizer may include a cable cuff having a wire reception cavity, and may include also be pressed laterally onto the cable. 
         [0011]    According to another aspect of the disclosure, a wire organizer may be included in an electrical junction assembly. Such an assembly may include a cable having discrete wires emerging from a jacket thereof, a series of electrical contacts coupled to the wires and an over-mold substantially surrounding both the series of electrical contacts and the wire organizer. The wire organizer may be coupled to the cable by a cable cuff, and coupled to the discrete wires by a wire comb that is coupled to the cable cuff by a bridge. The electrical contacts may comprise solder terminals in electrical communication with conductive traces contained on a flexible film. The over-mold may comprise a heat-shrinkable material. 
         [0012]    Also, a method of coupling wires to a series of electrical contacts is described. The method involves loading the free ends of the wires into wire receiving channels on a wire organizer, connecting each wire to an electrical contact and applying an over-mold to substantially surround the series of electrical contacts and wire organizer. The loading of the individual wires may be accomplished by clipping the wire organizer laterally onto the free ends of the wires. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present disclosure and, together with the detailed description of the embodiments given below, serve-to explain the principles of the disclosure. 
           [0014]      FIG. 1  is a perspective view of an electrical junction assembly according to one embodiment of the present disclosure; 
           [0015]      FIG. 2  is an enlarged perspective view of the electrical connection assembly of  FIG. 1  shown without the over-mold and with a cable cuff separated for clarity; 
           [0016]      FIG. 3  is an enlarged perspective view of the cable cuff of  FIG. 1 ; 
           [0017]      FIG. 4  is an enlarged perspective view of the wire comb of  FIG. 1 ; 
           [0018]      FIGS. 5A-5C  are perspective views of alternative embodiments of a wire comb of the present disclosure; 
           [0019]      FIGS. 6A and 6B  are perspective views a wire organizer of the present disclosure having a one-piece configuration; 
           [0020]      FIGS. 7A and 7B  are perspective views of an alternate embodiment of a one-piece wire organizer, which permits some axial movement of wires through the cable cuff; and 
           [0021]      FIGS. 8A and 8B  are perspective views of an alternate embodiment of a one-piece wire organizer without a free wire reception cavity. 
       
    
    
     DETAILED DESCRIPTION 
       [0022]    The attached figures illustrate embodiments of the present disclosure and are referenced to describe the embodiments depicted therein. Hereinafter, the disclosure will be described in detail by explaining the figures wherein like reference numerals represent like parts throughout the several views. 
         [0023]    Referring initially to  FIG. 1 , electrical junction assembly  10  includes a wire organizer  30  facilitating the connection of wires  21  to flexible circuit  50 . As described in greater detail below, wires  21  include an individual wire  22  and five discrete signal wires  24  ( FIG. 2 ) emerging from cable  20 . Wire organizer  30  includes a wire comb  35 , which separates wires  21 , and an optional cable cuff or clip  33 , which may be coupled to cable  20  thereby securing individual wire  22  and redirected power wires  23  thereto. Cable  20  and individual wire  22  are mechanically and electrically coupled to flexible circuit  50  as described in detail below. To protect this connection, over-mold  60  is formed by laminating or otherwise coating the electrical junction assembly  10  with a polymer, such as polyester, vinyl or other suitable material. In the case of a heat-shrinkable over-mold  60 , a sleeve of a heat-shrinkable material may be positioned over all or any portion of electrical junction assembly  10 . Heat applied to the over-mold  60  may then tend to cause the heat-shrinkable material to shrink in the radial direction, thereby forming a secure and effective environmental seal about the components contained within over-mold  60 . 
         [0024]    Referring now to  FIG. 2 , electrical junction  10  is depicted with over-mold  60  removed and cable cuff  33  separated for clarity. Cable  20  defines an axial direction generally in line with the cable jacket  25  and a generally perpendicular lateral direction. As shown, eight discrete wires emerge axially from cable jacket  25  and each is routed to transmit an electrical potential between two particular locations within the electrical device. Five of the discrete wires are signal wires  24 , and three are power wires  23 . Signal wires  24  are adapted for transmitting signals of relatively low power such as data and information, while power wires  23  are adapted to have adequate mass and surface area to dissipate the heat associated with electrical power transmission. Therefore, power wires  23  may be a larger gauge than signal wires  24 . 
         [0025]    The three power wires  23  reverse direction almost immediately after exiting jacket  25 . This abrupt redirection may give power wires  23  a tendency to pull away from the cable jacket  25 , which could compromise the integrity of the environmental seal created by over-mold  60  ( FIG. 1 ). Cable cuff  33  is adapted to restrain the power wires  23  against the exterior surface of the jacket  25 . Individual wire  22  is also restrained against the jacket adjacent the power wires  23 . Individual wire  22  connects at an opposite end (not shown) at a location distinct from the connection location of the opposite ends (not shown) of power wires  23 . For this reason, individual wire  22  is not routed through cable jacket  25 . Individual wire  22  may serve to transmit information similarly to signal wires  24 , and individual wire  22  may be a larger gauge wire than signal wires  24 . 
         [0026]    The five signal wires  24  and individual wire  22  collectively form wires  21 , which are connected to flexible circuit  50 . Wires  21  are routed through wire comb  35  where they are transitioned from the generally radial arrangement of round cable  20  to the side-by-side arrangement and particular pitch of the row of solder terminals  55  of flexible circuit  50 . This transition facilitates the connection of wires  21  at their free ends  29  to flexible circuit  50 . The conductor  27  of each wire  21  may be electrically and mechanically coupled to solder terminals  55  by soldering or any other suitable means. The wire comb  35  serves to separate and restrain the wires  21  to facilitate the connection to the solder terminals  55 , and thereafter adequate separation and spacing of the wires  21 . The solder terminals  55  are each in electrical communication with a conductive trace  53  contained in a flexible film  51 . Electrical insulators  63  may be positioned over alternating conductors  27  as shown to ensure each solder terminal  55  is electrically isolated from neighboring solder terminal  55 . Electrical insulators  63  may comprise a suitably sized length of a heat-shrinkable material similar to the material which comprises over-mold  60  ( FIG. 1 ). 
         [0027]    Referring now to  FIG. 3 , the cable cuff  33  is described in detail. Cable cuff  33  has an interior surface  71  and an exterior surface  73 . Open end  85  provides access to the interior and includes tapered entry surfaces  79  facilitating the lateral placement of cable cuff  33  onto cable  20 . Alternatively, cable  20  may be inserted axially through cable reception cavity  81 . Also on the interior of cable cuff  33 , and opposite the open end  85  is free wire reception cavity  83  through which wires  22 ,  23  may be routed. In operation, cable  20  and wires  22 ,  23  are inserted into the cable cuff  33  such that cable  20  is situated between wires  22 ,  23  and open end  85  such that wires  22 ,  23  are retained. The cable cuff  33  may compress the cable jacket  25  and wire insulation  28  such that a friction fit is formed preventing the cable cuff  33  from moving axially along the cable  20 . The exterior surface  73  of cable cuff  33  is generally rounded and filleted to facilitate handling and also to reduce the likelihood of sharp edges puncturing or tearing the over-mold  60 . Also, rounded edges  75  are provided to prevent damage to the cable jacket  25  or wire insulation  28 . 
         [0028]    Referring now to  FIG. 4 , wire comb  35  is described in detail. Wire comb  35  includes a body  87  with a length L approximating the length of the row of solder terminals  55 . The body  87  includes five wire receiving channels  90  adapted to accommodate the signal wires  24  and one enlarged wire receiving channel  91  adapted to accommodate the individual wire  22 . Wire receiving channels  90 ,  91  are open to two opposite faces  93 ,  95  of the body  87  and are spaced along the length L of the body  87  to transition the wires  21  from the radial arrangement to the side-by-side arrangement and spacing of the solder terminals  55 . As shown in  FIG. 4 , wire receiving channels  90 ,  91  may be arranged around the periphery of the body  87  such that multiple rows of wire receiving channels  90 ,  91  transition wires to a single row arrangement like the solder terminals  55 . Wire receiving channels  90  may also be open to a peripheral side  97  of the body  87  so that a wire  24  may be inserted laterally. A reduced-width insertion portion  99  is included in each wire receiving channel  90  so that a wire  24 , once inserted, tends to remain in place rather than escape through the open peripheral side  97 . Also, wire receiving channels  90  may be configured to form a light friction fit with the insulation  28  of the discrete wires  21  to prevent any unintended axial movement of the discrete wires  21 . 
         [0029]    In operation, cable cuff  33  and wire comb  35  may be applied during the cable assembly process by feeding the free ends  29  of discrete wires  21  through the appropriate channels axially. The light friction lit will allow the wire organizer  30  to remain in place until such time the cable  20  is to be assembled with other components into the electrical device or instrument. With the wire organizer  30  in place, the free ends  29  of the discrete wires  21  may be coupled to the appropriate electrical contact, for example by soldering conductors  27  to solder terminals  55 . Alternatively, the wire organizer  30  may be applied to the cable  20  and wires  21  after the free ends  29  have been coupled to their appropriate electrical contact by clipping the wire comb  35  and cable cuff  33  to the jacket  25  and insulation  28  laterally. Once in place, the wire organizer  30  maintains the proper position of the discrete wires  21  during and after the application of the over-mold  60 . 
         [0030]    Referring next to  FIGS. 5A through 5C , several alternate embodiments of a wire comb suitable for use with the present disclosure are presented. Wire comb  135  depicted in  FIG. 5A  features a single row of wire receiving channels  190  along a single peripheral side  197  of the body  187 . In some instances where access to an electrical junction assembly is limited to one direction, this configuration can facilitate installation of the wire comb  135 . Each wire receiving channel  190  includes a notch  194  opposite the open end  185  to allow the wire receiving channels  190  to flex slightly to facilitate the lateral insertion of a wire. An enlarged wire receiving channel  191  may be included for the introduction of larger gauge wires. 
         [0031]    Wire comb  235  depicted in  FIG. 5B  features a row of wire receiving channels  290  with no end open on a peripheral side  297  of the body  287 . Wires may be inserted axially through the wire receiving channels  290  and are thereafter positively restrained. A ramp  294  situated within each wire receiving channel  290  is configured prevent reverse axial movement of the wires by forming a light friction fit with the insulation of the wires. The configuration of wire comb  235  may be particularly useful, for example, in a low pressure molding process for application of a polymer such as over-mold  60  that subjects individual wires to forces tending to laterally displace wires from their position in wire comb  235 . Tapered entry surfaces  279  facilitate the axial insertion of the individual wires in the direction appropriate for ramps  294  to wedge the wire into place by forming a friction tit with the insulation. 
         [0032]    Wire comb  335  depicted in  FIG. 5C  features wire receiving channels  390  disposed between angled spokes  394  protruding from the body  387 . This configuration enhances the ease of installation. 
         [0033]    Next, referring to  FIGS. 6A and 6B , a wire organizer  630  is described having a one-piece configuration with cable cuff  633  and wire comb  635  coupled by bridge  637 . Bridge  637  maintains an axial spacing between the cable cuff  633  and the wire comb  635  and may also guide wires  621  into position by defining lateral offsets in any direction, for example, in the direction of height H. The embodiment shown is particularly adapted for installation by inserting cable  620  and wires  621  laterally into cable cuff  633  and wire comb  635 . The cable cuff  633  includes tapered insertion surfaces  679  and wire comb  635  includes notches  694  as described above with reference to  FIG. 5A . Also, bridge  637  is relatively wide and short having a support rib  639  to prevent the bridge  637  from breaking as wires  621  are pressed laterally into place. 
         [0034]    Referring now to  FIGS. 7A and 7B , wire, organizer  730  may be better suited for axial installation of cable  720  and wires  721  having a longer and narrower bridge  737  coupling cable cuff  733  to wire comb  735 . Also, cable reception cavity  781  and wire reception cavity  783  may be elongated to laterally capture cable  720  and wires  721 , but permit free axial movement through the cable cuff  733 , thus facilitating an axial installation. A friction fit may be formed only between wires  721  and wire receiving channels  790  of wire comb  735  to secure the axial position wire organizer  730 . A friction fit is thus not necessary on both components of the wire organizer  730 . 
         [0035]    Referring next to  FIGS. 8A and 8B , a one-piece wire organizer  830  is depicted with a bridge  837  coupling wire comb  835  to cable cuff  833 . Cable cuff  833  includes a substantially round cable reception cavity  883  with no cavity to accommodate individual wires. This demonstrates how a wire organizer  830  may be adapted for alternate cable constructions and wire routing schemes. For example, as shown in  FIG. 8B , wire  822  may be routed inside the cable jacket  825  such that wire organizer  830  only accommodates wires  821  emerging from cable jacket  825 . 
         [0036]    Although the foregoing disclosure has been described in some detail by way of illustration and example, for purposes of clarity or understanding, certain changes and modifications may be practiced within the scope of the appended claims.

Technology Category: h