Abstract:
A telecommunications electrical connector positions the contacts in a manner to reduce crosstalk problems. An insert assembly positions the spring contacts within a jack for electrical contact with the contacts of a plug. The insert assembly staggers the relative positions of adjacent spring contacts in the y-direction, and staggers the spring contact pivot points in the x-direction, yet maintains a common contact region for all the spring contacts for contacting the contacts of the plug. The distal ends of alternating spring contacts are positioned so as to increase the isolation between adjacent springs. The insert assembly includes selected air passages between spring contacts mounted to the insert assembly to increase isolation and selected dielectric to increase crosstalk cancellation.

Description:
This is a continuation of application Ser. No. 09/231,736, file Jun. 15, 1999, now U.S. Pat. No. 6,334,792. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to electrical connectors, and specifically to electrical connectors having closely spaced contacts where interference from crosstalk in the connector is a concern. 
     BACKGROUND OF THE INVENTION 
     Various electrical connectors are known for use in the telecommunications industry to transmit voice, data, and video signals. It is common for some electrical connectors to be configured to include a plug which is connectable to a jack mounted in the wall, or as part of a panel or other telecommunications equipment mounted to a rack or cabinet. The jack includes a housing which holds a plurality of closely spaced spring contacts in the appropriate position for contacting the contacts of a plug inserted into the jack. The spring contacts of the jack are often mounted to a printed circuit board, either vertically or horizontally. An RJ45 plug and jack connector system is one well known standard including closely spaced contacts. 
     Crosstalk between the contacts in telecommunications connectors is a concern due to the close spacing of the contacts. U.S. Pat. Nos. 5,399,107; 5,674,093; and 5,779,503 are examples of various connectors including jacks and plugs which attempt to address the problem of crosstalk. It is desired to improve performance of the electrical connectors, such as an RJ45 connector, where crosstalk problems increase as higher frequencies are transmitted through the connector. 
     SUMMARY OF THE INVENTION 
     One aspect of the present invention relates to an electrical connector for connecting to a plug having a plurality of electrical contacts, the connector including a plurality of first and second metallic spring contacts. Each of the first and second spring contacts includes: 1) a circuit board connection end for connecting to a circuit board; 2) a first longitudinally extending section; 3) a main bend section; and 4) a second longitudinally extending section engageable with a contact of the plug. The first longitudinally extending section, the main bend section, and the second longitudinally extending section define a general V-shape. The second longitudinally extending section of the first spring contacts have two linear portions joined at a bend portion. The second longitudinally extending section of the second spring contacts extends linearly. A dielectric contact housing holds the spring contacts, wherein the contact housing defines an x-axis, a y-axis and a z-axis. The contact housing is configured for receipt of the plug in a direction of the x-axis, wherein the first and second spring contacts are arranged such that: 1) the first and second spring contacts alternate along the z-axis; 2) the first longitudinally extending sections of the first spring contacts are in a plane displaced along the y-axis from a plane defined by the first longitudinally extending sections of the second spring contacts; and 3) the main bends of the first spring contacts are displaced along the x-axis from the main bends of the second spring contacts. 
     A printed circuit board is mounted to the first and second spring contacts at the circuit board connection ends. The printed circuit board may define either a plane parallel to the x and z-axes, or a plane parallel to the y and z axes. 
     In the case of a one preferred embodiment, the contact housing includes a base for receiving each of the first longitudinally extending sections of the first and second spring contacts, wherein the base defines at least one channel extending in the direction of the x-axis between the first longitudinally extending sections of the first spring contacts and the first longitudinally extending sections of the second spring contacts. In the case of another preferred embodiment, the contact housing includes a base having a divider extending from a top surface, with the divider defining a plurality of alternating first and second channels. Each of the first and second channels receives one of the first and second spring contacts. The first channels extend at an angle to the x and y-axes, and the second channels extend parallel to the x-axis. 
     Another aspect of the present invention relates to an electrical connector for connecting to a plug having a plurality of electrical contacts where the connector includes a plurality of first and second metallic spring contacts. Each of the first and second spring contacts includes: 1) a circuit board connection end for connecting to a circuit board; 2) a first longitudinally extending section; 3) a main bend section; and 4) a second longitudinally extending section. The first longitudinally extending section, the main bend section, and the second longitudinally extending section define a general V-shape. A dielectric contact housing holds the spring contacts, wherein the contact housing defines an x-axis, a y-axis and a z-axis. The contact housing is configured for receipt of the plug in a direction of the x-axis, wherein the first and second spring contacts are arranged such that: 1) the first and second spring contacts alternate along the z-axis; 2) the first longitudinally extending sections of the first spring contacts are in a plane displaced along the y-axis from a plane defined by the first longitudinally extending sections of the second spring contacts; and 3) the contact housing including a base for receiving each of the first longitudinally extending sections of the first and second spring contacts, wherein the base defines at least one channel extending in the direction of the x-axis between the first longitudinally extending sections of the first spring contacts and the first longitudinally extending sections of the second spring contacts. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a jack assembly in accordance with the present invention including two jacks, each for receiving a plug; 
     FIG. 2 is a cross-sectional side view of the jack assembly of FIG.  1  through one of the jacks and showing a vertically mounted printed circuit board; 
     FIG. 3 is a perspective view of the vertical insert assembly used in the jack assembly of FIG. 1; 
     FIG. 4 is an end view of the vertical insert assembly of FIG. 3; 
     FIG. 5 is a top view of the vertical insert assembly of FIG. 3; 
     FIG. 6 is an opposite end view of the vertical insert assembly of FIG. 3 to the view of FIG. 3; 
     FIG. 7 is a bottom view of the vertical insert assembly of FIG. 3; 
     FIG. 8 is a side view of the vertical insert assembly of FIG. 3; 
     FIG. 9 is a cross-sectional side view of the vertical insert assembly of FIG. 3, taken along lines  9 — 9  of FIG. 5; 
     FIG. 10 is a further cross-sectional side view of the vertical insert assembly of FIG. 3, taken along lines  10 — 10  of FIG. 5; 
     FIG. 11 is a cross-sectional side view like the view of FIG. 9, showing a plug with its contacts in electrical contact with the spring contacts of the vertical insert assembly; 
     FIG. 12 is a further cross-sectional side view like the view of FIG. 10, showing the plug in electrical contact with the spring contacts of the vertical insert assembly; 
     FIG. 13 is a side view of the two configurations of the spring contacts of the vertical insert assembly of FIG. 3, shown in their relative positions; 
     FIG. 14 is a perspective view of the contact housing of the vertical insert assembly of FIG. 3; 
     FIG. 15 is an end view of the contact housing of FIG. 14; 
     FIG. 16 is a perspective view of a horizontal insert assembly for use with a horizontally mounted printed circuit board, for an alternative jack assembly; 
     FIG. 17 is an end front view of the horizontal insert assembly of FIG. 16; 
     FIG. 18 is a top view of the horizontal insert assembly of FIG. 16; 
     FIG. 19 is a bottom view of the horizontal insert assembly of FIG. 16; 
     FIG. 20 is a cross-sectional side view of the horizontal insert assembly of FIG. 16, taken along lines  20 — 20  of FIG. 18; 
     FIG. 21 is a further cross-sectional side view of the horizontal insert assembly of FIG. 16, taken along lines  21 — 21  of FIG. 18; 
     FIG. 22 is a cross-sectional side view of the horizontal insert assembly like the view of FIG. 20, showing a plug in electrical contact with the spring contacts of the horizontal insert assembly; 
     FIG. 23 is a further cross-sectional side view of the horizontal insert assembly like the view of FIG. 21, showing the plug in electrical contact with the spring contacts of the horizontal insert assembly; 
     FIG. 24 is a side view of the two configurations of the spring contacts of the horizontal insert assembly of FIG. 16, shown in their relative positions; 
     FIG. 25 is a perspective view of the contact housing of the horizontal insert assembly of FIG. 16; 
     FIG. 26 is an end view of the contact housing of FIG. 25; and 
     FIG. 27 is a top view of the contact housing of FIG.  25 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention is concerned with improving performance of electrical connectors including closely spaced electrical contacts where crosstalk may be a problem, especially as increasingly higher frequency signals are desired for use with the electrical connectors. 
     FIGS. 1 and 2 show an example of one jack assembly  10  including two jacks  12  each sized for receipt of a plug  14  (See FIGS. 11,  12 ,  22  and  23 ). Plug  14  typically includes a plurality of metallic contacts  16 ,  18  for making contact with electrical spring contacts  40 ,  42  within each jack  12 . Contacts  16 ,  18  are housed in a housing  20  of plug  14 . Plug  14  also includes a latching tab  22  for mounting plug  14  to jack  12 . As shown in the illustrated preferred embodiments, jack  12  and plug  14  are  8  contact type ( 4  twisted pair) connectors as in an RJ45 connector. 
     As shown in FIG. 2, each jack  12  includes a cavity  30  for receipt of plug  14 . An outer housing  32  encloses an insert assembly  34 . In the example of FIG. 2, insert assembly  34  is a vertical insert assembly including a vertically mounted printed circuit board  36 . Insert assembly  34  further includes a plurality of metallic spring contacts  40 ,  42  mounted to a contact housing  44 . Spring contacts  40 ,  42  have first ends  50 ,  52  disposed within cavity  30  for contacting contacts  18 ,  20  of plug  14 . Spring contacts  40 ,  42  define a general V-shape. First ends  50 ,  52  flex inwardly as the plug  14  is inserted into cavity  30 . Opposite ends  54 ,  56  of spring contacts  40 ,  42  extend from contact housing  44  to mount to printed circuit board  36 , such as by soldering. 
     While the present invention is particularly useful in an RJ45 connector, other connectors including jack and plug arrangements where the electrical contacts are held in close proximity may also benefit by including one or more of the features disclosed herein for reducing crosstalk. 
     With respect to an RJ45 connector, there are eight contacts. The plugs and jacks have eight aligned contacts  1 - 2 - 3 - 4 - 5 - 6 - 7 - 8  (4 each of contacts  16 ,  18 , and spring contacts  40 ,  42 , respectively, each arranged in an alternating manner). See the example embodiments of FIGS. 6 and 19 for the contact numbering. The plug contacts have four pairs of twisted pair cable terminated to them. These pairs are typically paired as follows:  4 - 5 ,  3 - 6 ,  1 - 2  and  7 - 8 . Because of the pair arrangement, there is unbalanced capacitance and inductance which creates the crosstalk between pairs  2 - 3 ,  3 - 4 ,  5 - 6  and  6 - 7 . Therefore, it is desirable that these contacts be isolated as much as possible from each other within the jack. Furthermore, the pairs in the jack can be balanced by positioning certain contact combinations together to cancel crosstalk. These pair combinations are  1 - 3 ,  2 - 4 ,  3 - 5 ,  4 - 6 ,  5 - 7  and  6 - 8 . Therefore, it is desirable for the jack to have a lower amount of coupling between contacts  2 - 3 ,  3 - 4 ,  5 - 6  and  67 , and to have a higher amount of coupling between contacts  1 - 3 ,  2 - 4 ,  3 - 5 ,  4 - 6 ,  5 - 7  and  6 - 8 . 
     The present invention utilizes various features in the jack in the preferred embodiments to address crosstalk concerns. Staggering every other spring contact ( 1 ,  3 ,  5  and  7  in one row, and  2 ,  4 ,  6  and  8  in the other row, see FIG. 6) allows for the spring contacts to be moved further apart where isolation is desired, and the spring contacts where coupling is desired to be increased, are positioned closer to each other. The spring contacts are also positioned so that they are not in the same contact plane for a significant portion. The free ends of the spring contacts are in the same plane at the contact area with the plug, but before and after they are not in the same plane. (See FIGS.  11  and  12 ). Each set of four spring contacts pivots at a location that is not in line with the other set of four spring contacts. (See FIGS. 9,  10  and  13 ). Additionally, the set of four spring contacts which has a smaller angle relative to the other set has a further bend after its contact point with the plug to further increase the isolation between the spring contacts. Further, the contact housing utilizes air spaces in selected locations to further isolate certain spring contacts, and solid material in other selected locations to increase coupling. Positioning material with a higher dielectric constant will increase the coupling and, therefore, crosstalk between two conductors, and air, which has a lower dielectric constant than the housing material, will have less coupling between the two spring contacts. While all of the above noted features are preferred, variations are possible which utilize one or more selected features to improve performance by reducing crosstalk. 
     Referring now to FIGS. 3-15, vertical insert assembly  34  is shown in greater detail. Contact housing  44  includes a base  46  having a front  60 , a top  62 , a bottom  64 , and a rear  66 . It is to be appreciated that contact housing  44  can be positioned in any orientation as desired in jack assembly  10  or other mounting arrangement. Vertical insert assembly  34  in FIGS. 3-15 defines an x-axis, a y-axis and a z-axis (See FIG. 3) for purposes of this description. 
     Base  46  includes two sets of longitudinal openings  78  and  80  arranged in a row, each for receipt of a spring contact  40 ,  42 . Longitudinal openings  78 ,  80  extend in the direction of the x-axis. Each set is staggered in the y-axis direction to facilitate spacing of selected spring contacts to isolate some and couple others. Front channels  82 ,  84  communicate with longitudinal openings  78 ,  80 , and also receive spring contacts  40 ,  42 . Each first front channel  82  communicates with one of first longitudinal openings  78  to receive one first spring contact  40 . Each second front channel  84  communicates with one of second longitudinal openings  80  to receive one second spring contact. Second front channels  84  are deeper than first front channels  82  in the x-axis direction. This results in spacing of the spring contacts  40 ,  42  in the x-axis direction at the apex region of each spring contact, and along the free ends except for the contact areas. Base  46  further includes top and bottom openings or channels  88 ,  90  to facilitate manufacture of contact housing  44  from molded materials, such as plastic, for example polyetherimide. 
     Base  46  further includes longitudinal channels or passageways  92 ,  94  positioned between the sets of longitudinal openings  78 ,  80 . This results in better decoupling of selected spring contacts, as noted above. 
     First spring contact  40  includes a board contact end section  100 , and a coaxial and longitudinally extending main section  102  positioned in longitudinal opening  78  in base  46 . A front bend  104  is positioned in front channel  82  of base  46 . Longitudinal contact section  106  extends upwardly at an angle from base  46  in the FIGS. so as to be positioned in the cavity  30  of the jack  12  for electrical contact with the plug  14 . Contact section  106  further includes a bend region  108  which positions bend region  108  at an angle relative to a remainder of contact section  106 . Contact section  106  of spring contact  40  is comprised of two linear segments in the illustrated embodiment. 
     Second spring contact  42  includes a board contact end section  110 , and a longitudinally extending main section  112 , both of which extend parallel to board contact section  100  and longitudinally extending main section  102  of first spring contact  40 . A front bend  114  is positioned in front channel  84  of base  46 . Front bend  114  is larger in height than front bend  104  of first spring contact  40 . Second spring contact  42  includes a longitudinal contact section  116  extending upwardly at an angle from base  46  so as to be positioned in the cavity  30  of the jack  12  for electrical contact with the plug  14 . Contact section  1   16  of spring contact  42  is comprised of a linear segment in the illustrated embodiment Both of spring contacts  40 ,  42  are convenient shapes to manufacture and maintain with a sufficient amount of flexibility to achieve proper contact with the contacts of plug  14 . 
     As shown by referencing FIGS. 3-15, longitudinally extending sections  102 ,  112  are staggered in the y-axis direction in base  46 . Front bends  104 ,  114  are staggered in the x-axis direction, and bend  108  positions the distal end  109  of spring contact  40  at an angle relative to distal end  118  of contact section  116  of second spring contact  42 . Further, base  46  advantageously positions base material between spring contacts  40 ,  42  where more coupling is desired, and air is advantageously positioned in other selected areas between longitudinal passageways  92 ,  94  between spring contacts where less coupling between contacts is desired. In this manner, jacks  12  can be provided which address crosstalk concerns such as in catagory  6  systems, with bandwidths of 250 Megahertz. 
     Referring now to FIGS. 16-27, a horizontal insert assembly  134  is shown including a contact housing  144  and two sets of spring contacts  140 ,  142 . Contact housing  144  includes a base  146  defining a front  160 , a top  162 , a bottom  164  and a rear  166 . Horizontal insert assembly  134  defines an x-axis, a y-axis, and a z-axis (See FIG. 16) for the purposes of this description. It is to be appreciated that horizontal insert assembly  134  can be mounted in any orientation as desired in a jack assembly. Horizontal insert assembly  134  includes a horizontally positioned printed circuit board  150  (See FIGS.  20  and  21 ), instead of a vertical mount as in vertical insert assembly  34 . 
     Base  146  includes to opposed sidewalls  152 , and a rear connector assembly  154  for terminating wires to horizontal insert assembly  134 . Base  146  includes a divider  180  for positioning individual first and second spring contacts  140 ,  142 . Divider  180  has side walls which define first and second channels  182 ,  184 . Each of first channels  182  includes a slight angled surface  186 , angled relative to the x and y-axes. Second channels  184  each include a longitudinal surface  188  extending generally parallel to the x-axis, and at a lower elevation from surface  186  along the y-axis. Base  146  further includes openings  190 ,  192  for allowing spring contacts  140 ,  142  to pass through base  146  in the direction of the y-axis. Both first and second spring contacts  140 ,  142  define a general V-shape. 
     First spring contact  140  includes a board contact end section  200 , a first bend  202 , followed by a main longitudinal section  204  for receipt in angled surface  186 . A second bend  206  is followed by a longitudinal contact section  208 . A further bend  210  positions distal end  209  of contact section  208  at an angle relative to a remainder of contact section  208 . Second spring contact  142  includes a board contact end section  220 , a first bend  222 , followed by a longitudinal main section  224  which resides in second channel  184 . Second spring contact  142  further includes a second bend  226  followed by a longitudinal contact section  228 . 
     As shown in the FIGS., board contact end sections  200 ,  220  are staggered in two rows as shown in FIG.  19 . Main sections  204 ,  224  are not parallel, and one set of spring contacts  140  includes a bend  210  in the contact section  208  which positions the distal ends of spring contacts  140 ,  142  so that the ends are not parallel. Also, bends  206 ,  226  are positioned such that the pivot points of spring contacts  140 ,  142  are not in the same line. These features cooperate to isolate selected spring contacts to reduce crosstalk especially at higher frequencies as may be encountered in a catagory standard. 
     Base  146  includes an elongate tab  240  extending toward a rear end of the assembly  134 . A distal end of tab  240  includes a ramped surface  242  diverging outwardly. Tab terminates in a planar surface  244  facing end. 
     While the various features of each of horizontal insert assembly  134  and vertical insert assembly  34  cooperate in an advantageous manner, it is to be appreciated that the noted features may be used individually or in various combinations as desired to address crosstalk concerns. Also, while horizontally mounted printed circuit boards and vertically mounted printed circuit boards are shown, it is to be appreciated that angled printed circuit boards are also possible with an appropriately configured contact housing. 
     The above specification, examples and data provide a complete description of the manufacture and use of the composition of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.