Abstract:
A shielded cable connector ( 20 ) which minimizes EMI and crosstalk between closely situated assembly modules is disclosed. The shielded cable connector comprises a connecting latch ( 28 ). The shielded cable connector facilitates insertion of the shielding housing ( 20 ) into a shielded header connector ( 24 ), and prevents inadvertent removal of the shielding housing ( 20 ) from the shielded header ( 24 ).

Description:
This application claims the benefit of Provisional Application No. 60/019,168, filed Jun. 5, 1996. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to cable connectors. In particular, the invention relates to a shielded cable connector for reducing electromagnetic interference (EMI) and crosstalk between and among closely situated cable connections. 
     BACKGROUND OF THE INVENTION 
     High density back panel connectors such as METRAL™ connectors, sold by Berg Electronics, are available in various standardized lengths. Such high density connectors have a standardized contact grid pitch of 2 mm and standardized mating interface dimensions. Such connectors have been marketed widely by several companies and are widely known in the industry. 
     It is generally known in the art, that such connectors are modularized and can be combined and assembled to form connectors having a particular desirable length. Typically, this is accomplished by stacking standard length headers and receptacle connector modules. To form both sides of an electrical interconnection, for example, an assembly module, or cable terminator matching the desired length can be plugged into an assembly of stacked header connectors. 
     Although stacking such connectors is known in the art, problems remain with regard to combining connectors in this manner. Because the close proximity of the modules and the close spacing of contacts, these systems are susceptible to crosstalk. The connectors may encounter EMI from external sources as well as from each other. Also, inserting a mating module into a series or stack of header connectors is often difficult. Such modular arrangements have in the past provided insufficient guidance mechanisms so as to insure proper connection between mating arrays of modules. Further, assembly modules such as those forming cable connectors often are inadvertently disconnected from the header connector. Thus, prior art connectors lack a reliable means for preventing movement of cable connectors once they are engaged with the composite header. 
     Therefore, there remains a need for a cable connector which minimizes EMI and crosstalk, provides sufficient guidance so as to easily attach an assembly module to a header connector, and provides a means of adequately securing an assembly module to a header connector. 
     SUMMARY OF THE INVENTION 
     The present invention, fulfills this need with a shielded high density cable interconnection system. The present inventive shielded interconnection system comprises an assembly module, a header connector adapted for accepting the assembly module, a shielding housing for enveloping the assembly module, and a latch member for securing the shielding housing and the assembly module to the header connector. 
     The shielded interconnection system comprises a shielded header having a first sidewall, a second sidewall, and a rear header wall having multiple terminals extending therefrom for receiving the assembly module. The first sidewall and the second sidewall have receiving slots for guiding the shielding housing into the shielded header connector. The first sidewall and second sidewall each further have grounding springs which contact dimple recesses located on the shielding housing when the shielding housing is inserted into the header connector. The second sidewall also has a recess located therein for accepting the latch member. 
     The shielding housing of the cable connector comprises a first half shell and a second half shell. The shielding housing further comprises a means for attaching the first half shell with the second half shell so as to form a 360 degree shielding around the perimeter of said assembly module. 
     The latch member of the interconnection system comprises an elongated distal object having at least one first leg end for insertion into the shielded header connector, and a second spring arm end for latching onto the shielding housing. The latch member functions to immobilize the relative movement of the shielded header and the shielding housing and thereby prevent inadvertent disconnection of the cable connector from the shielded header connector. 
     Other features of the present invention are described below. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will be better understood, and its numerous objects and advantages will become apparent by reference to the following detailed description of the invention when taken in conjunction with the following drawings, in which: 
     FIGS. 1A through 1D depict a prior art METRAL™ receptacle connector and header connector; 
     FIG. 2 provides a perspective view of the basic component parts of the present invention; 
     FIG. 3 provides a perspective view of a stacked header connector with various assembly modules; 
     FIG. 4 provides a view of a partially exploded assembly module and shielding housing; 
     FIGS. 5A through 5F provide a detailed view of the latch and latch slot features of the shielding housing; 
     FIG. 6 provides a cross-sectional view of the latch and latch slot features of the shielding housing; 
     FIG. 7 provides a view of a flat stamp layout of one half shell of the shielding housing; 
     FIGS. 8A through 8D provide various views of one half shell of a shielding housing formed from the flat stamp layout shown in FIG. 7; 
     FIG. 9 provides a view of a partially exploded three assembly modules partially enveloped in the shielding housing of FIGS. 7 and 8; 
     FIGS. 10A through 10G provide various views of the inventive shielded header connector; 
     FIGS. 11A through 11G provide various views of the inventive connecting latch; 
     FIGS. 12A through 12D provide various views of a shielding housing and connecting latch assembled with a shielded header connector; 
     FIGS. 13A through 13C provide various views of a connecting latch connector integrated with a shielded header; 
     FIG. 14 provides a view of the 5×2 assembly module of FIG. 4 fully enveloped in a shielding housing; 
     FIG. 15 provides a view of an exploded 5×6 assembly module and partially enveloped in the shielding housing of FIG. 9; 
     FIG. 15A provides a view of a 5×6 assembly module fully enveloped in the shielding housing as shown in FIG. 9; 
     FIG. 16 provides a view of three 5×2 assembly modules of the type shown in FIGS. 4 and 14 received in a header connector and secured by a latch mounted in a header connector wall; 
     FIG. 17 provides a view of the three 5×2 assembly modules secured in header connector; 
     FIG. 17A provides a view from a bottom perspective of the assembly module illustrated in FIG. 17; 
     FIG. 18 provides a view of a 5×6 assembly module partially inserted into a header connector; 
     FIG. 19 provides a view of the 5×6 assembly module of FIG. 18 fully inserted into a header connector. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIGS. 1A through 1E depict a prior art receptacle connector and header connector such as the METRAL™ line of connectors sold by Berg Electronics. As shown in FIG. 1A, a receptacle connector  2  includes a matrix of contact terminals  4  mounted within a housing area electrically connected to tails  6 . The distance between the center of any two adjacent rows (e.g. row a and b) of terminals  4  is 2 mm. Similarly, the distance between the center of any two adjacent columns (e.g.  23  and  24 ) of terminals is 2 mm. Thus, the basic connection grid for a prior art METRAL™ receptacle is 2×2 mm. Prior art METRAL™ receptacle connectors  2  typically come in modules having six columns and are therefore 12 mm in length. Although the receptacle  2  shown in FIG. 1A has four rows of terminals  4 , it will be understood that the number of terminal  4  rows may vary. Generally, the basic receptacle connector module contains  5  rows and  6  columns and is referred to as a 5×6 receptacle module. The present invention is described below with reference to FIGS. 2 through 19, all of which assume a 5×6 receptacle connector. It should be noted that the receptacle connector  2  shown in FIG. 1 is a portion of a composition of several receptacle connector modules which are shown stacked together, end to end. 
     FIG. 1B provides a side view of a prior art METRAL™ receptacle connector  2 . Prior art METRAL™ receptacle connector  2  is characterized by dual beam contact terminals attached to right angle bent tails  6 , which are thru-mount or press-fit to a printed circuit board  8 . 
     FIG. 1C provides an elevated perspective view of a prior art METRAL™ receptacle connector  2 . As shown in FIG. 1C, a receptacle connector  2  has two raised rails  10  on one side with two polarizing latch ears  12  and fixing pegs  14  (FIG. 1B) on the opposite side. 
     FIG. 1D is a view of a prior art straight through header connector  16 . In one contemplated form of the invention pins extending from the rear  17  of the header connector  16  are received by the terminals  4  of receptacle connectors  2 , to convert the receptacles  2  for receipt of receptacle type cable connectors, later described. Similar to the receptacle connector  2 , header connector modules typically are 5×6 in dimension so as to cooperate with the receptacle connectors  2  of similar dimension. Alternatively, a right angle pin header, preferably shielded, can be used in place of the combination of receptacle  2  and straight-through header  16 . 
     FIG. 2 provides a simplified perspective view of the present invention. As shown in FIG. 2, a shielding housing  20  envelopes an assembly module  22  which is subsequently attached to a shielded or die cast header  24  to provide a modular shielded-interconnection. 
     The shielding housing  20  is made from an alloy which is environmentally acceptable and which provides sufficient insulating qualities so as to prevent EMI and crosstalk. In the presently preferred embodiment, the shielding housing  20  is made from a beryllium copper alloy with a thickness of about 0.15 mm. Other suitable materials could alternatively used. 
     Also shown is a connecting latch  28 . A connecting latch  28  attaches to the wall  30  of the shielded header  24  and latches onto the shielding housing  20 . The connecting cable latch  28  operates to secure the shielding housing  20  and enveloped assembly module  22  to the shielded header  24 . 
     Although not visible in FIG. 2, the basic assembly module  22  may contain, for example, two rows of terminals with each row containing five terminals. Typically, the terminals include a front receptacle contact portion for mating with the pins of header  24  and rear portions to which individual wires from a cable are attached, for example, by an IDC termination. As suggested by the Figure, when an assembly module  22  is plugged into the header connector  24 , the assembly module attaches to the header so as to be ninety degrees rotated from the receptacle connector. Therefore the columns of assembly terminals  26  are connected indirectly through the header  24  to the rows of terminals in the receptacle connector  2 . Similarly, the rows of terminals  26  in the assembly module  22  are indirectly connected to the columns of terminals  4  in the receptacle connector  2 . In relation to the matrix terminals  4  of the receptacle connector  2 , the assembly module  22  is said to be a 5×2 module, where  5  represents the number of rows in the receptacle connector  2  to which the assembly module  22  is connected and  2  represents the number of columns in the receptacle connector  2  to which the assembly module  22  is connected. As noted above, each terminal  4  column in the receptacle connector is 2 mm deep. Therefore, a 5×2 assembly module  22  such as that shown in FIG. 2 which is connected to two columns of terminals on the receptacle connector  2 , is 4 mm deep. 
     The shielded header connector  24  pictured in FIG. 2 is a 5×6 module, i.e. it is connected to 5 rows and 6 columns of the receptacle connector  2 . Therefore, there is room in the header connector  24  to receive three of the 5×2 assembly modules. Of course, assembly modules  20  of the present invention may vary in size. 
     FIG. 3 provides a view of a side by side vertically stacked arrangement of shielded header connectors  26 . As shown, shielding housings  20  of the present invention may come in other sizes such as 5×6  90  and 5×8  92 . An assembly module may be enveloped individually in a shielding housings  20  or alternatively several assembly modules  20  may be enveloped together in single shielding housing  90 ,  92 . Also shown in FIG. 3, the connecting latch  28  component of the present invention can likewise vary to accommodate the various combinations of assembly modules, e.g. 5×6 connecting latch  94 . 
     FIG. 4 provides a partially exploded view of a 5×2 assembly module  22  enveloped in a shielding housing  20 . As shown, the inventive assembly module  22  has three side studs  44  on each of its two side surfaces  40 . Similarly, two studs  46  are located on each of the module&#39;s lateral surfaces  42 . 
     The shielding housing  20  comprises two half shells  50 . The half shells  50  have appropriately located side recesses  52 ,  54  and lateral recesses  55  which cooperate with the previously mentioned studs  44 ,  46  when the two shells  50  are fitted over the connector module  22 . Thus, when the two half shells  50  are drawn together around the assembly module  22 , the side studs  44  are received into the side recesses  52 ,  54 . Likewise, the lateral studs  22  are received into the lateral recesses  55 . The studs  44 ,  46  operate to insure that the assembly module  22  is properly seated in the shielding housing  20 . 
     Also shown in FIG. 4, the two half shells  50  of the shielding housing  20  comprise a series of latches  56  and latch slots  58 . When the half shells  50  are placed together around the assembly module  22 , the latches  56  insert into a corresponding slot  58  on the opposing half shell  50 . The latch  56  and slot  58  combination along with the interconnection of the lateral studs  46  and lateral recesses  55  operate to secure the two half shells  50  around the assembly module  22 . 
     FIG. 14 provides a perspective view from an opposing angle of the two half shells  50  and the assembly module  22  of FIG. 4 in a fully assembled position. As shown in FIG. 14, the two half shells  50 , by means of the studs ( 44 ,  46 ), recesses ( 52 ,  55 ,  54 ), latches  56 , and latch slots  58 , lock into each other to form a 360 degree shell over the periphery of the assembly module  22  as well as a substantial surface of the signal cable. As shown in FIG.  14  and as was mentioned above, the assembly module  20  is a 5×2 module  22 . 
     FIGS. 5A through 5C provide detailed frontal views of the latch  56  and slot  58  component of the shielding housing  20  in various stages of interconnection. FIGS. 5D through 5F provide corresponding rear views. 
     FIGS. 5A and 5D provide a view of the latch  56  and slot  58  when unconnected or in an “open” state. As shown, the latch  56  comprises a sheared cantilever beam  60  located on a tab  62 . The tab  62  has been displaced over a small bend  64  with respect to the plane of shielding housing  20 . Although the cantilever beam  60  is shown to be sheared from the tab, it should be noted that the cantilever beam instead of being sheared from the tab could alternatively be a detent or bump and the beam would function properly to secure the latch into the latch slot. 
     Also shown in FIGS. 5A and 5D, the receiving slot  58  is formed between a flat lug  66  and the plane of the shielding housing which is represented by dotted line  68 . The flat lug  66  is connected to the shielding housing  20  by two bent members  70 . A flat bias  72  extends from the flat lug  66 . 
     FIGS. 5B and 5E provide a view of the latch  56  partially engaged with the latch slot  58 . As shown, during the initial engagement, the tab  62  located on the latch  56  side contacts the flat bias  72  located on the corresponding latch slot  58  side. Provided the two are on the same plane, the latch  56  is easily inserted into latch slot  58 . 
     FIGS. 5C and 5F provide a view of the latch  56  and latch slot  58  in the fully engaged or “home” position. As shown, the latch tab  62  engages behind the flat lug  66  edge and thereby secures the latch  56  in the latch slot  58 . 
     FIGS. 6A through 6C provide a cross-section view of the latch  56  and latch slot  58  in the three stages of engagement described above, i.e. open, engaged, and home. FIG. 6A provides a view of the latch  56  and latch slot  58  in an open state. FIG. 6B provides a view of the latch  56  and latch slot  58  in a partially engaged state. FIG. 6C provides a view of the latch  56  and latch slot  58  in the home position. 
     FIG. 7 provides a flat stamp layout view of a half shell  50  of the shielding housing  20 . The flat stamp layout can be folded along lines A and B so as to form a half shell  50  into which three assembly modules may be enveloped. 
     As shown in FIG. 7, circular side recesses  52  and lateral recesses  55  are located at one end of the stamped shield half shell  50 . Located linearly away from each of the circular side recesses  52  is a somewhat larger diameter recess  52 . In the area of the half shell between each pair of recesses is located, but not shown, a raised dimple recess  54  which, as will be discussed below, comes into contact with a grounding spring located in a header connector. It should be noted that the half shell  50  depicted in FIG. 7 has three pairs of circular recesses each of which is meant to engage the lugs of an assembly module. Along each side of the half shell  50  are located alternatively tabs  100  and flat biases  102 . The tabs  100  are located opposite the flat biases  102  which appear at the same level on the opposing side of the half shell  50 . Thus, when the half shell  50  is folded and placed around an assembly module  22 , the tabs  100  and flat biases  102  are located opposite one another. It should be noted that the tab  100  and flat bias  102  of FIG. 7 are machined into the latch  56  and latch slot  58  described above in connection with FIG.  4 . 
     At the furthest end of the half shell  50  are located two lobes  108 . At that same end of the half shell  50  is located a central neck  110  with an adjoining flap  112 . The central neck  110  and adjoining flap  112  encircle the cable when the half shell  50  is formed and placed around the assembly module  22 . 
     FIGS. 8A through 8D provide various views of a half shell  50  formed by folding the stamped half shell  50  of FIG. 7 along lines A and B. FIG. 8A provides a view of the portion of the half shell folded up from line A. FIG. 8C provides a view of the portion of the half shell  50  folded up from line B. FIG. 8B provides a view of the interior of a side of the half shell  50 . As shown in FIG. 8B, the half shell  50  has three combinations ( 52  and  54 ) of recesses, each of which is meant to engage with the studs of an assembly module. FIG. 8D provides a view of the exterior of the half shell  50  from a perspective opposite that of FIG.  8 B. 
     FIG. 9 provides a partially exploded view of a shielding housing  20  composed of half shells  50  formed around three assembly modules  22 . The lateral stud  46  cooperates with the lateral recess  55  so as to secure the half shells  50  to the assembly modules  22 . The side studs  44  on each module cooperate with the side recesses  52 ,  54  so as to insure that each module is properly seated in the housing  20 . 
     The raised dimple recess  54  and the studs  44  protruding through the side recesses  52  also function to guide the shielding housing  20  into a header connector  24 . As explained below in connection with FIG. 10, when the shielding housing  20  is placed into a header connector, the protruding side studs  44  and the dimple recess  54  cooperate with slots located in the header connector walls thereby providing a guide for easy insertion of the shielding housing  20  into the header connector. 
     FIG. 15A provides a perspective view of the three assembly modules fully enveloped within the assembly module of FIG.  9 . 
     FIGS. 10A through 10G provide various views of the inventive shielded header connector  24 . The header connector depicted is a 5×6 module. FIG. 10A provides a view of the interior of a side wall of the header connector  24 . As shown, the header connector  24  has three slots  130  on the interior side wall. In the present invention, such slots  130  appear on the two side walls  134 . These slots  130  accept the raised dimple recesses  54  and protruding side studs  44  located on the exterior of a shielding housing  22 . The dimple recess  54  and studs  44  are received into the slots  130  and thereby guide the shielding housing  20  and the assembly modules located therein, into the correct location within the header connector  24 . 
     FIG. 10C provides a sectional view of the header connector  24 . As shown, one side wall  134  of the header connector contains a recess  132 . This recess  132  is designed to accept the leg portion  140  of the connecting latch  28 . FIG. 10G shows a sectional view of this side wall. As shown, the recess can accept three separate leg portions  140  of a connecting latch  28 . These legs may be either part of a single latch or multiple latches. 
     FIG. 10D provides a end sectional view of the header connector  24  from the perspective of one looking into the base terminal wall of the header connector  24 . As shown, the base wall  136  has multiple terminals extending therefrom. The header module shown in FIG. 10D is a standard type and therefore the terminals are in a 5×6 arrangement. Along the sides of the terminal walls are located a series of ground springs  150 . A ground spring  150  is located on each side wall aligned between each row of terminals on the base wall. When a shielding housing  20  is inserted into a header connector  24 , the dimple recesses  54  on the exterior of the housing come into contact with the ground springs  150  and thereby provide grounding to the shielding housing. 
     As noted above in the discussion of FIG. 10A, the present inventive header connector  24  contains three slots  130  on two opposite header walls  134 . These slots accept the dimple recesses  54  located on the exterior walls of the shielding housings  20  which are placed into the header  24 . In contrast, in prior art headers two dimple ribs were located on a single header wall opposite a single slot located on the opposite header wall. The increase in the number of slots in the header walls of the present invention allows for more ground contact springs on the header walls which results in better force balance and multi-point grounding. Furthermore, the use of multiple slots on two header walls provides superior guidance when the shielding housing is inserted into the header. It is also within the scope of the present invention, to form the header walls so that dimples are present on one wall and slots are present on the other wall. In this embodiment the surface of the shielding housing would also have dimples on one exterior surface and slots formed on the opposite surface. This has the effect of polarizing the connection between the header connector and the shielding housing. 
     FIGS. 11A through 11G provide various perspective views of connecting latch  28 . The connecting latch  28  shown is one typically used with a 5×2 assembly module. As shown, such a latch  28  has a leg  140  which enters the recess  132  located in the header-wall previously shown in FIG.  10 . At the opposite extremity of the latch  28  is located a spring clamp  142  or shoulder which is used to fix the shielding housing  20  to the header connector  24 . 
     FIGS. 12A through 12D provide various perspective views, partially in section of the header connector  24  in various stages of cooperation with the latch  28  and connector receptacle  20 . As shown in FIG. 12C, the latch  28  secures the shielding housing  20  to the header connector  24 . The leg  140  portion of the latch  28  is inserted into the header wall recess  132 . The spring clamp  142  portion of the latch  28  is secured to the shielding housing  20 . The latch  28  thereby operates to secure the shielding housing  20  and the assembly modules  22  located therein to the header connector  24 . It is also within the scope of the present invention to integrally form latch  28  and header connector  24 . 
     FIG. 12D provides a side view of the shielding housing  20 . As shown, the dimple recesses  54  extend from the wall of the shielding housing  20 . Referring to FIG. 12C, when the shielding housing  20  is inserted into the header connector  24 , each dimple  54  contacts a ground spring  150  located on the interior wall of the header connector  24 . The contact between the dimples  54  and the ground springs  150  completes the grounding loop between the shielding housing  20  and the header connector  24 . Local areas of the dimple recesses  54  may be gold plated so as to minimize impedance. 
     FIG. 12B provides a side lengthwise view of the latch  28  and header connector  24  combination shown in FIG.  12 C. As shown in FIG. 12B, two header connector modules  160  are shown stacked together. A first header connector module  160  has three 5×2 latches  28  inserted thereto. The sectional view of the header connector shows the leg  140  portion of each of the three latches  28  located in the header wall latch slot  132 . A second header connector module  160  has a single 5×6 latch  94  inserted therein. The three legs  140  of the single 5×6 latch  94  can be seen in the sectional depiction of the header module  160 . 
     FIG. 12A provides a lengthwise view of the base wall of the header connector modules  160  shown in FIG.  12 B. As shown, each 5×2 module has a header wall ground spring  150  associated with it. By providing a ground spring  150  for each 5×2 module, the present invention insures sufficient grounding for each assembly module. 
     The present inventive shielded connector maintains the modular characteristics of prior art METRAL™ connectors. As discussed above, FIG. 11 depicts a single latch  28  with a single latch spring clamp  142 . FIG. 12B illustrates that a header module  160  might have three individual 5×2 latch modules  28  attached or alternatively have one 5×6 module  94 . As shown in FIG. 13B a latch may also overlap header modules. 
     Referring to FIG. 13B, the header module  160  shown to the furthest right in the Figure has three 5×2 latches  38  inserted thereto. The middle header module  160  has a single 5×2 latch  28  along with a portion of a 5×6 latch  94  inserted thereto. The 5×6 latch  94  overlaps between the module  160  shown in the middle and the module  160  shown to the furthest left. The single integrated 5×6 latch  94  can be used with its three legs  140  inserted into one header module, or two legs in a first module and the third leg in the adjacent header module. The inventive header connector  24  has been designed to allow for such overlap and modular use of components. The ability to overlap latches between modules has the added benefit of aligning adjacent modules  160  so as to maintain unity and end-to-end stackability of the total connector module. 
     The modularity of the present invention is not limited to the latches but extends to assembly modules as well. FIGS. 16,  17 , and  17 A provide various perspective views of three 5×2 assembly modules in various stages of connection with a header connector  24 . As noted above the standard header connector module  24  pictured has a 5×6 dimension. Thus, the header module  24  can accept three 5×2 assembly modules. 
     FIGS. 18 and 19 provide a similar view of a single 5×6 assembly module inserted in various stages of engagement with a standard sized 5×6 header module. In contrast with the 5×2 modules illustrated in FIGS. 16 and 17, the single 5×6 assembly module fills the 5×6 header. Thus, a header module of the present invention may receive assembly modules of varying sizes. 
     The invention as set forth above is likewise described in U.S. Provisional Patent Application No. 60/019168, filed Jun. 5, 1996 and titled “Shielded Cable Connector”, which is hereby incorporated by reference. 
     The present invention may be employed in other specific forms without departing from the spirit or essential attributes thereof. For example, any number of materials may be used in manufacturing the shielding housing. Likewise different means for securing the shielding housing to the assembly modules might be used. While the invention has been described and illustrated with reference to specific embodiments, those skilled in the art will recognize that modification and variations may be made without departing from the principles of the invention as described hereinabove and set forth in the following claims.