Patent Publication Number: US-6338643-B1

Title: Stuffer cap mechanism for an electrical connector

Description:
REFERENCE TO RELATED APPLICATION 
     This application is related to U.S. patent application Ser. No. 09/250,186 of John J. Milner, Joseph E. Dupuis, Richard A. Fazio, and Robert A. Aekins, filed Feb. 16, 1999, U.S. Pat. No. 6,193,526 and entitled “Wiring Unit with Angled Insulation Displacement Contacts” and to U.S. patent application Ser. No. 09/250,187 of John J. Milner, Richard A. Fazio, and Robert A. Aekins, filed Mar. 4, 1999, 2000, and entitled “Wiring Unit with Paired In-Line Insulating Displacement Contacts”, the subject matter of both of which arc hereby incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a wiring unit of an electrical connector for communication and data transmission systems. The wiring unit includes a stuffer cap that may couple to a portion of the wiring unit so that the latch for attaching the wiring unit to a support (e.g., a faceplate) is protected during the termination of electrical wires to electrical wire insulation displacement contact (IDC) terminals of the wiring unit. More particularly, the present invention includes a stuffer cap that can be selectively coupled to one portion of the wiring unit to protect the latch during termination of the electrical wires and to the terminals or IDC of the wiring unit to help stop oxidation and corrosion. 
     BACKGROUND OF THE INVENTION 
     Due to significant advancements in telecommunications and data transmission speeds over unshielded twisted pair cables, the connectors (jacks, receptacles, patch panels, cross connects, etc.) have become critical factors in achieving high performance in data transmission systems, particularly at the higher frequencies. Some performance characteristics can degrade beyond acceptable levels at new, higher frequencies in the connectors unless adequate precautions are taken. 
     Often, wiring is pre-existing. Standards define the geometry for the connectors, such as the size and connection to existing faceplates and other support structures, thus making any changes to the wiring and to the connector geometry cost prohibitive. 
     The use of unshielded twisted pair wiring was created prior to the need for high speed data transmissions. Thus, while using the existing unshielded twisted pair wiring and complying with the existing standards, connectors must be developed that fulfill the performance requirements of today&#39;s higher speed communications, in order to maintain compatibility with the existing connectors. 
     One method to improve performance has been to use a stuffer cap coupled to the terminals of a jack or interconnection device for an electrical connector. The stuffer cap covers the twisted pair cables after they have been attached to the terminals, and retards or stops oxidation or corrosion on the terminals and termination wires. This retardation of corrosion helps to stop low level contact (voltage resistance) spikes. Examples of this type of stuffer cap are disclosed in U.S. Pat. Nos. 5,186,647 to Denkmann et al and 4,403,200 to Chen. 
     Generally, the stuffer cap configuration has not changed the geometry of the connector and allows ajack to be coupled to a conventional keystone envelope on a faceplate. The jack typically has a latching mechanism that has one latch or protrusion located on the “bottom” of the jack or opposite side of the wiring terminals and an opposing latch or protrusion located on the “top” of the jack or on the same side as the wiring terminals. The structure of the latching mechanism on the jack is generally perpendicular to the face of the jack that mates with a faceplate or other support. The protrusions couple to recesses in the keystone envelope and thereby hold the jack in place. However, at least one of these latching mechanisms may be damaged during the wire termination process. 
     Typically the wire termination process is performed using a 10-impact tool. Usually, the jack is positioned with the terminals extending upwardly and away from a support surface to increase efficiency of the wire termination process. However, this orientation typically positions one of the latching mechanisms between the housing of the jack and the support surface on which the jack is placed. The latching mechanism can be damaged by the force of the impact tool forcing the connector and its latching mechanism against the support surface. With a damaged latching mechanism, the jack will not be able to be properly coupled to the faceplate. 
     Examples of conventional of stuffer caps are disclosed in U.S. Pat. Nos. 6,116,943 to Ferrill et al.; 5,626,490 to Pitts et al.; 5,228,872 to Liu; 5,186,647 to Denkmann et al; and 4,403,200 to Chen. 
     SUMMARY OF THE INVENTION 
     Accordingly, an object of the present invention is to provide an electrical connector having a stuffer cap that can couple to the wiring unit in manner that protects the faceplate latching mechanism during wire termination. 
     Another object of the present invention is to provide an electrical connector having a stuffer cap that couples to the wire-connecting unit to retard or stop oxidation or corrosion on the terminals and termination wires. 
     Yet another object of the present invention is to provide an electrical connector having a stuffer cap that is simple and inexpensive to manufacture and use. 
     The foregoing objects are basically obtained by an electrical connector having a housing with opposite first and second sides, a stuffer cap attachment on the second side and a support latching portion adjacent the attachment on the second side. Electrical wire insulation displacement contact terminals are coupled to the housing and extend from the first side. A stuffer cap can be selectively coupled on the housing first surface over the insulation displacement contact terminals and to the attachment overlying the second surface. 
     The foregoing objects are further obtained by a method for assembling a wiring unit for an electrical connector, the wiring unit including a housing having opposite first and second sides. A stuffer cap attachment extends from the second side and a support latching portion is adjacent the attachment on the second side. Insulation displacement contact terminals are coupled to the housing, the terminals being at least partially covered by a plurality of protrusions on the housing. The method includes, positioning a stuffer cap overlying the second side and coupling the stuffer cap to the stuffer cap attachment, the stuffer cap extending farther from the second surface than the latching portion. The stuffer cap is placed on a surface, the stuffer cap separating the latching portion from the surface. Then electrical wires are positioned on the insulation displacement contact terminals and forces are exerted on the electrical wires, thereby coupling the electrical wires to the insulation displacement contact terminals coupled to the housing. The stuffer cap absorbs the force transferred to the housing and protect the latching portion. The stuffer cap can then be separated from the attaching portion and attached to the protrusions on the housing. 
     By forming an electrical connector and performing the method according to the invention, the stuffer cap will help retard or stop oxidation or corrosion on the terminals and termination wires. Additionally, the stuffer cap can be coupled to the housing side opposite the terminals so that when an impact tool is used to terminate the electrical wires to the electrical connector, the latching portion is protected to avoid being damaged. 
     Other objects, advantages and salient features of the invention will become apparent from the following detailed description, which, taken in conjunction with the annexed drawings, discloses a preferred embodiment of the invention. 
     As used herein, terms, such as “front”, “rear”, “upwardly”, “downwardly”, “forwardly” and “backwardly”, are intended to describe relative directions, and do not limit the electrical connector to any specific orientation. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Referring to the drawings which form a part of this disclosure: 
     FIG. 1 is an exploded side elevational view in section of an electrical connector and faceplate support according to the present invention. 
     FIG. 2 is a side elevational view in section of the electrical connector of FIG. 1 with a stuffer cap coupled to the stuffer cap attachment portion, prior to engagement of the terminal wires. 
     FIG. 3 is a bottom perspective view of the electrical connector of FIG. 2 with the stuffer cap attached to the stuffer cap attachment portion. 
     FIG. 4 is a bottom view of the stuffer cap of FIG.  1 . 
     FIG. 5 is a top view of the electrical connector of FIG. 1 after insertion of the wires, but prior to coupling of the stuffer cap. 
     FIG. 6 is top view of the stuffer cap of FIG.  4 . 
     FIG. 7 is a bottom view of the electrical connector of FIG.  5 . 
     FIG. 8 is an end view of the electrical connector with the stuffer cap of FIG.  3 . 
     FIG. 9 is a top perspective view of the electrical connector of FIG. 1, with the stuffer cap coupled to the IDC terminals, but without the terminal wires coupled thereto. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     A high density electrical connector  10  for telecommunication systems and for coupling to a faceplate  50  or other support according to the present invention is illustrated in FIGS. 1 and 2. The connector comprises a connector body or housing  12  and a printed circuit board  16  on which terminals  18  are mounted. The terminals  18  are standard  110  electrical wire insulation displacement contacts (IDC), and couple to standard electrical or terminal wiring or wires  20 , as shown specifically in FIG.  5 . Through printed conductors on the circuit board, terminals  18  are electrically and mechanically coupled to resilient contacts  22 . The resilient contacts extend into the connector body in a configuration for electrical connection to a conventional or standard plug, particularly an RJ plug. A stuffer cap  24  is coupled to the housing  12 , protecting the wires  20  from oxidation or corrosion. 
     Faceplate  50  is conventional, and has keystone envelope  48  with grooves or indentations  46 . 
     Connector body  12  is preferably in the form of a jack. However, the connector body can be of any desired form, such as a plug, cross connect or any other connector in the telecommunications or data transmission field. 
     Connector body or housing  12  is preferably a hollow plastic two piece device having a main portion  23  and a terminal cover portion  25 . However, the housing may be formed from any material that would help insulate the electrical wires, terminals and circuit board from the outside environment, such as rubber or any other polymer. The main portion  23  has a forwardly opening plug receiving cavity  26  for receiving a conventional RJ plug. A shelf  30  extends rearwardly from the main portion  23  of connector body  12  and receives a portion of circuit board  16 , specifically the portion of the circuit board on which the resilient contacts  22  are mounted. Shelf  30  supports circuit board  16  and facilitates the coupling between the circuit board and the connector body. Shelf  30  of main portion  23  also has two indentations  53  along the surface  34  and end face  37 , as seen specifically in FIGS. 7-9. Indentations  53  are substantially rectangular recesses in the edge of face  37  and remove a portion of the corner common to face  37  and surface  34 . Housing  12  also has protrusion  40  extending from side  44 . 
     Faceplate or support latching mechanism or portion  32  extends outwardly from surface  34  of main portion  23 . As seen in FIG. 1, member  31  is preferably unitary with and extends substantially perpendicularly from lower surface  34 . Member  31  curves forward towards face  36  and forms latching mechanism  32 . Latching mechanism is preferably integral with and extends from member  31  and is substantially parallel with surface  34 . Tapered protrusion  38  extends from latching mechanism  32 . Adjacent latching mechanism  32  is stuffer cap attachment portion or mechanism  52 . Attachment portion  52  extends from and is preferably unitary with member  31 . Portion  52  extends rearwardly and away from face  36  or toward face  37  of housing  12  and is substantially parallel with lower surface  34 . Portion  52  has a protrusion or portion  54  that curves toward surface  34 . Alternatively, stuffer cap attachment portion  52  can be a separate device and located away from member  31  and latching portion  32  or may couple thereto by any means desired. 
     Cover portion  25  is preferably placed over the terminals  18 , which are coupled to circuit board  16 . Cover portion  25  is fixed to main portion  23  using adhesive or any other means desired. However, portion  25  does not necessarily have to be fixed to portion  23  and may merely be positioned next to and abut portion  23 . 
     As seen in FIGS. 1 and 2, a portion  55  of the terminals extends from the cover portion  25 , allowing wires  20  to be electrically connected thereto. Cover portion  25  preferably has a plastic, generally rectangular portion or base  56  with twelve protrusions  58  and  60  extending upwardly and substantially perpendicularly from the portion  56 , as seen in FIGS. 1,  2  and  5 . Protrusions  58  and  60  are preferably integrally formed with portion  56  and are oriented at an angle of about 30 degrees to a longitudinal axis  62  of the cover portion  25 . Alternatively, the protrusions can be oriented in any direction, whether it is parallel, perpendicular or any other angle to the axis  62 . Preferably, the protrusions are formed in groups of three, as seen specifically in FIG. 5, with the middle protrusions  58  extending further upwardly and away from the portion  56  than the protrusions  60 , as seen in FIGS. 1 and 2. Additionally, cover portion  25 , preferably has a post  64  positioned at one end and approximately in the center (i.e., along axis  62 ) of the cover portion with regard to sides  66  and  68 . Post  64  extends to approximately the same height as protrusions  58 . 
     As seen in FIGS. 3,  4  and  8 , stuffer cap  24  is preferably U-shaped in transverse cross-section and has a substantially rectangular portion or base  70  having a first end  72  and second end  74 . Two sidewalls or arms  76  and  78  extend outwardly and substantially perpendicularly from the base. However, stuffer cap  24  may be any configuration that would protect wires  20  and latching mechanism  32 . First end  72  has a substantially perpendicular semi-cylindrical wall  80  extending away from base  70  to approximately the same height as walls  76  and  78 . Wall  80  preferably extends along an arc of about 180 degrees; however, wall  80  may be any shape, height or size desired. Walls  76  and  78  extend substantially the entire length of sides  82  and  84  and along portions  71  and  73  of second end  74 , as seen in FIG.  4 . At second end  74 , a portion  79  of base  70  is recessed between the facing ends of walls  76  and  78 , forming a substantially rectangular opening, as seen specifically in FIGS. 4 and 6. Extending outwardly and substantially perpendicular to base  70  are two parallelepiped protrusions  85 . Protrusions  85  conform in shape to fit in the indentations  53  in main portion  23  of housing  12 , as seen in FIGS. 2 and 8. The coupling of protrusions  85  with the indentations  53  fixes the stuffer cap  24  in place overlying surface  34  when the stuffer cap is coupled to the attachment portion  52 . 
     Stuffer cap  24  is preferably plastic and has a plurality of protrusions or members  86  extending upwardly or inwardly and substantially perpendicularly from base  70 . Protrusions  86  are preferably unitarily formed with base  70  and are oriented at an angle of about 60 degrees to a central longitudinal axis  88  of the base, as seen in FIG.  4 . However, the stuffer cap may be of any material that insulates the electrical wires and terminals from the outside environment, such as rubber or any other polymer. The protrusions can be oriented in any direction, whether it is parallel, perpendicular or any other angle to the axis  88  conforming to the orientations of insulation displacement contact terminals  18  and protrusions  58  and  60 . 
     The protrusions preferably form pairs  90 ,  92 ,  94 ,  96 ,  98 ,  100 ,  102  and  104  and extend inwardly from either of sidewalls  76  or  78  toward the second end  74  and central axis  88 , as seen in FIG.  4 . Each pair of protrusions in formed along a similar line and each pair is substantially parallel to the other pairs extending from a respective sidewall, as seen in FIGS. 3 and 4. For example, pairs  90 ,  92 ,  94 , and  96  are substantially parallel to each other and pairs  98 ,  100 ,  102 , and  104  are substantially parallel to each other. Additionally, the protrusions are preferably formed to be oriented approximately perpendicularly to the protrusions  58  and  60  of cover portion  25  and to frictionally fit within spaces created by protrusions  58  and the adjacent protrusions  60  when the stuffer cap is mounted thereon. 
     Stuffer cap  24  also has five substantially rectangular apertures or holes  106 ,  108 ,  110 ,  112  and  114  extending entirely through the base  70 . However, the holes do not necessarily have to extend through base  70  and may be grooves or depressions in base  70 . Additionally, the holes may be any configuration, such as square, oval, or any other polygon desired. Holes  106 ,  108 ,  110  and  112  are positioned in the same orientation and direction as the protrusions  86 , that is, extending approximately 60 degrees relative to axis  88 . Each hole is positioned in-between two pairs of protrusions, as seen specifically in FIG.  4 . For example, holes  106 ,  108 ,  110  and  112  are positioned between pairs  90  and  92 ,  94  and  96 ,  98  and  100 , and  102  and  104 , respectively. The holes preferably do not extend the entire distance of the pairs of protrusions, but may be any size or dimension desirable. Hole  114  is preferably adjacent second end  74  and extends between the innermost protrusions  86  of pairs  96  and  104 . 
     Assembly 
     Initially, electrical connector  10  is preferably shipped with the stuffer cap  24  coupled to the attachment portion  52 . Stuffer cap  24  is attached to the attachment portion by simply sliding the cap along surface  34  such that base  70  engages attachment portion  52  and biases it away from surface  34 . The attachment portion mates with or engages the base  70  by protrusion  54  snapping into hole  114  and the attachment portion returning to is normal position relative to the surface  34 . As seen in FIGS. 3 and 8, the protrusion  54  on the attaching portion  52  extends through hole  114  in the stuffer cap  24 , with recess  71  fitting snugly around member  31  of the latching mechanism  32 . Additionally, protrusions  85  of the stuffer cap fit into indentations  53  on housing  12 . As seen in FIG. 2, the stuffer cap  24  overlies and extends from surface  34  with stuffer cap sidewalls  76  and  78  extending beyond both the latching mechanism  32  and the attaching portion  52  and extending over half the length of the housing  12 . A majority of the stuffer cap  24  supports the end of the housing  12  that has the cover portion  25  and terminals  18  attached thereon. This positioning of the stuffer cap  24  supports electrical connector  10  and protects the latching mechanism  32  during termination of the wires  20  from damaging engagement with the support surface on which the free edges of sidewalls  76  and  78  engage. Additionally, the fitting of protrusions  85  into indentations  53  along with the coupling to attachment portion  52  and member  31  prevents the stuffer cap from sliding or releasing during wire termination and/or shipping. Since sidewalls  76  and  78  are substantially perpendicular from base  70 , they provide a strong support protecting latching mechanism  32  and protrusions  86  from damage during termination of wires  20 . 
     Generally, wires  20  are terminated by placing the electrical connector  10  on a level support surface and using a  110 -type impact tool ( 116 ) to force the wires  20  between the terminals  18  and coupling the wires thereto, as is known in the art. The present invention allows the stuffer cap  24  to be positioned between the surface and the housing  12 , separating the latching portion from the support surface. Additionally, the stuffer cap absorbs the majority of force delivered by the impact tool to the wires and transferred to the housing. 
     After terminating the wires  20 , the stuffer cap  24  may be removed from the attaching portion  52  by simply applying force to the stuffer cap away from member  31 , such that base  70  forces attachment portion away from surface  34  and out of aperture  114  and protrusions exit from indentations  53 . Stuffer cap  24  is then coupled to the terminals  18 , engaging the wires  20  and securing wires to the terminals  18 . The protrusions  86  on the stuffer cap are adapted to mate or fit in-between and are frictionally held by the protrusions  58  and  60  on the cover portion  25  of the housing  12 , thereby protecting and holding the wires therein. Additionally, as seen in FIG. 9, a portion of the protrusions  58  fit within the apertures  106 ,  108 ,  110 , and  112  and the post  64  fits within the semicylindrical space defined by wall  80 , thereby aligning stuffer cap  24  over cover portion  25 . Alignment of the stuffer cap during the vertical displacement that occurs during termination is critical to consistently achieving a stable termination wire/contact surface. The electrical connector  10  is then coupled to a faceplate or other support, protrusions  38  and  40  engaging keystone envelope  48  of faceplate  50  using grooves or indentations  46 , in a conventional manner. 
     Stuffer cap  24  may also be used instead of an impact tool. The wires  20  may be partially inserted in-between the terminal, stuffer cap  24  is then positioned over the terminals  18  and forced into position. The protrusions  86  push the wires into position between the terminals, securing the wires  20  to the terminals  18 . 
     While a specific embodiment has been chosen to illustrate the invention, it will be understood by those skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention as defined in the appended claims.