Abstract:
A cable connector has a shroud including an elongated recess and provided with an internal grounded shield which extends within and substantially along the entire length of the elongated recess. The cable connector further has a cable receptacle including an elongated housing for cable conductors and a housing shield surrounding the housing. The housing and shroud shield are juxtaposed with one another along the entire length of the recessed inner surface of the shroud to form a double shield cover protecting the cable connectors within the shroud when of the cable receptacle is attached to the shroud. The shroud shield may be formed as separate plates located on each inner shroud wall and may include springs for engaging a metal panel. The shroud bottom wall may include compressible tubular parts which form openings in the shield bottom wall to secure contacts.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to structures for connecting and grounding a shielded connector and a receiving connector, and more particular to structures in which a shielding layer of a cable can be reliably grounded. 
     This application is based on Patent Application No. Hei11-184284 filed in Japan, the contents of which are incorporated herein by reference. 
     2. Background Art 
     In recent years, with higher speed and higher frequency of transmission signals in electronic devices, it has become more necessary to take measures to fully protect connectors used in the electronic devices from electromagnetic interference (referred to as EMI hereinafter). Especially for cable connectors used for connecting a shielded cable and a circuit board, the structure of the shielding part of the cable connector and the attachment structure of the cable connector around the shielding part are important in these measures because undesired electromagnetic radiation can be suppressed if the shielding layer of the shielded cable can be grounded with low impedance through the shielding part of the cable connector. 
     In one example, shown in FIGS. 20 and 21, a connector  1  is provided with cables  4  which are covered with a shielding shell  3 , in a cover  2 . A panel connector  5  is U-shaped in cross-sectional view, and is provided on the other side of a conductive panel  6 . Contact pins  7  project inside the panel connector  5 . 
     As the connector  1  is inserted to the panel connector  5 , the contact pins  7  become inserted to contacts  8  of the connector  1  and the cables  4  become connected to a circuit and so on (not shown). Spring parts  9  are formed extending over a front edge of the cover  2  in the shielding shell  3 . The spring parts  9  are kept in contact with the conductive panel  6  when the connector  1  is inserted into the panel connector  5 , so that the shielding shell  3  can be grounded to the conductive panel  6  under enough contact pressure to achieve grounding applied by the spring parts. A locking device  10  which can engage the panel connector  5  is provided on one side of the cover  2 . This structure is described in Japanese Unexamined Patent Application Hei 7-320816. 
     However, the prior art described above has a disadvantage that it is easy for the spring part  9  to suffer damage and deformation as a result of hitting other members when the connector  1  is inserted, because the spring part  9  is provided at the front edge of the connector  1  along the direction of insertion. Additionally, it takes a long time to attach the spring part  9 , especially because, when the connector  1  is inserted, the attachment must be performed carefully so as not to deform the spring part  9  through contact with the surroundings of the opening formed in the conductive panel  6 . 
     Additionally, the prior art also has another disadvantage that it is difficult to ensure the appropriate value of the contact pressure to achieve grounding, because, in a side of the connector  1  in which the locking device  10  is provided, there is a part in which the spring part  9  cannot be positioned because of space requirements for the locking device  10  and the locking device  10  cannot be provided on both sides, for example, because of miniaturization of the connector  1 . 
     In consideration of the above circumstances, the present invention provides structures for connecting a shielded connector and a receiving connector and grounding them, in which a cable can be reliably attached without damage and deformation of the spring parts or spring members, even when the connectors are packaged with high density. 
     SUMMARY OF THE INVENTION 
     In order to resolve the above-described problem, a structure for connecting a shielded connector and a receiving connector comprises a connector provided with a housing which holds a cable; and a receiving connector attached to a circuit board, which receives the housing so that the cable is electrically connected to the circuit board; wherein the receiving connector has a shroud and a male contact within the shroud, a shielding member connected electrically to a shielding layer of the cable is provided on the outer wall of said housing, a shielding member is provided on the inner wall of the shroud, the surroundings of the cable can be shielded by both of the shielding members when the connector is inserted into the shroud, and contact springs are provided in the shroud to bring about elastic contact between one shielding member and the other shielding member so that both shielding members are electrically connected to each other, and grounding parts for grounding the circuit board which is electrically connected to the shielding member provided in the shroud are formed in the shielding member provided in the shroud. 
     As a result of the arrangement described above, the shielding member in the shielded connector can make reliable electrical connection with the shielding member in the receiving connector within the shroud by means of contact springs, and the shielding layer surrounding the cable can be reliably grounded to the circuit board through the grounding parts in the shielding member in the receiving connector. 
     A structure for connecting a shielded connector and a receiving connector comprises a connector provided with a housing which holds a cable; and a receiving connector attached to a circuit board, which receives the housing so that the cable is electrically connected to the circuit board; wherein the receiving connector has a shroud and a male contact within the shroud, a conductive panel which is fixed at the opening edge of the shroud and through the opening of which the connector passes, is provided between the connector and the shroud, a shielding member connected electrically to a shielding layer of the cable is provided on the outer wall of the housing, a shielding member is provided on the inner wall of the shroud, the surroundings of the cable can be shielded by both of the shielding members when the connector is inserted into the shroud, and contact springs are provided in the shroud so as to bring about elastic contact between on shielding member and the other shielding member so that both shielding members are electrically connected to each other, and grounding springs are formed in an extending part of an edge of the shielding member provided in the shroud so that the grounding springs make elastic contact with the rear side of the conductive panel. 
     As a result of the arrangement described above, when the shielded connector is inserted into the shroud in the receiving connector, the shielding member in the connector can make reliable electrical connection with the shielding member in the receiving connector by means of contact springs and the shielding layer surrounding the cable can be reliably grounded to the conductive panel due to the elastic contact between the grounding springs of the shielding layer in the receiving connector and the conductive panels. 
     According to another aspect of the present invention a structure for connecting a shielding connector and a receiving connector is provided on the outer wall of the housing with a shell-shape, the shielding member provided on the inner wall of the shroud has a case-shape, the contact springs are provided on the outer wall of the shielding member which has a shell-shape and which covers the housing of the connector, and the contact springs can be in contact with the shield member which has a case-shape and which is provided on the inner wall of the shroud when said connector is inserted into the shroud. 
     As a result of the arrangement described above, both shielding members can make reliable electrical connection with each other by means of contact springs provided in the shielded connector and the shielding layer surrounding the cable can be reliably grounded to the circuit board through the grounding parts formed in the shielding member in the receiving connector. 
     In accordance with a further aspect, the present invention has a structure, wherein the shielding member provided on the outer wall of the housing has a shell-shape, the shielding member provided on the inner wall of the shroud has a case-shape, and the contact springs are provided on the shield member which has a case-shape and which is provided on the inner wall of the shroud, the contact springs can be in contact with the outer wall of the shielding member which has a shell-shape and which covers the housing when the connector is inserted into the shroud. 
     As a result of the arrangement described above, both shielding members can make reliable electrical connection with each other by means of contact springs provided in the shielded connector and the shielding layer surrounding the cable can be reliably grounded to the circuit board through the grounding parts formed in the shielding member in the receiving connector. 
     Furthermore, an inventive structure has the grounding parts which are formed from extensions of the shielding member provided on the circuit board side of the shroud. 
     As a result of the arrangement described above, the extensions can be grounded to the circuit board whenever the shroud is installed in the circuit board. 
     In accordance with another feature of the present invention a shielding member is provided in the shroud as a plate-typed shielding plate, and the shielding plate and the shielding member provided in the connector are arranged to be electrically connected to each other by means of the contact springs which are provided either on the shielding plate or on the shielding member provided in the connector. 
     As a result of the arrangement described above, the shielding member can be simplified. 
     Still another feature of the present invention is a structure, wherein the grounding springs which are in contact elastically with the conductive panel are provided on at least one side of the opening edge of the shroud. 
     As a result of the arrangement described above, grounding can be achieved by means of the minimum number of grounding springs. 
     The present invention further has a structure, wherein the locking member is provided between the connector and the shroud of the receiving connector and fixes the connector and the shroud of the receiving connector when the connector is inserted into the shroud. 
     As a result of the arrangement described above, reliable connection between the shielded connector and the receiving connector can be achieved. 
     According to yet another feature of the present invention, a structure for connecting a shielded connector and a receiving connector has a shielding member provided in the shroud is provided with both said grounding parts and said grounding spring. 
     As a result of the arrangement described above, the shielding member can be grounded both with the conductive panels and the circuit board. 
     In the structure for grounding a shield connector and a receiving connector, in accordance with the invention, a connector provided with a housing which holds a cable is inserted into a shroud of the receiving connector attached to a circuit board, which receives the housing so that the cable is electrically connected to the circuit board; wherein a shield layer of the cable is grounded to conductive panels which are fixed tat an opening of the circuit board or the shroud, through the shielding member provided in the housing and the shielding member provided in the shroud. 
     As a result of the arrangement described above, the shielding layer surrounding the cable can make reliable electrical contact with the circuit board or the conductive panel through the shielded connector and the receiving connector. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective diagram showing a first embodiment of the present invention. 
     FIGS. 2A and 2B showing the first embodiment of the present invention in an attached state, and FIG. 2A is a cross section along the line A—A in FIG. 2B, and FIG. 2B is a side view thereof. 
     FIG. 3 is an exploded cross section of the first embodiment of the present invention. 
     FIG. 4 is a perspective diagram of the main part showing the first embodiment of the present invention. 
     FIG. 5 is an exploded cross section of a second embodiment of the present invention. 
     FIG. 6 is a cross view showing a third embodiment of the present invention. 
     FIG. 7 is a cross view showing a fourth embodiment of the present invention. 
     FIG. 8 is a perspective diagram showing a fifth embodiment of the present invention, and corresponds to FIG.  1 . 
     FIG. 9 is a cross view showing the fifth embodiment of the present invention. 
     FIGS. 10A and 10B are a front view and a plane view showing a sixth embodiment of the present invention, respectively. 
     FIG. 11 is a perspective diagram showing a seventh embodiment of the present invention. 
     FIGS. 12A and 12B show the seventh embodiment of the present invention in an attached state and FIG. 12A is a cross section along the line A—A in FIG. 12B, and FIG. 12B is a plane view thereof. 
     FIG. 13 is a perspective diagram of the main parts of the seventh embodiment of the present invention. 
     FIG. 14 is a perspective diagram showing an eighth embodiment of the present invention, and corresponds to FIG.  1 . 
     FIG. 15 is a cross section of the eighth embodiment of the present invention. 
     FIGS. 16A to  16 C are a front view, a plane view and a side view, showing a ninth embodiment of the present invention, respectively. 
     FIGS. 17A to  17 C are a front view, a plane view and a side view, showing another aspect of the eighth embodiment of the present invention, respectively. 
     FIG. 18 is an exploded cross section of another embodiment of the present invention. 
     FIG. 19 is an enlarged cross section of the embodiment shown in FIG. 18 in a fixed state. 
     FIG. 20 is a cross section of the conventional art in an installed state. 
     FIG. 21 is a perspective diagram showing the conventional art. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Hereinafter, several embodiments of the present invention are described in reference to the drawings appended. 
     FIGS. 1 and 4 show a first embodiment of this invention, which is applied to a structure for connecting a shielded connector and a receiving connector used, for example, in a telephone exchange. As shown in FIG. 1, a connector  11  is inserted into a shroud  13  of a receiving connector U which is attached to a circuit board  12 . As shown in FIGS. 2 and 3, in the connector  11 , a cable  14  is held by a cover  15  and a housing  17  to hold wires  16  is provided at the front end of the cover  15 . The wires  16  inside the cable are shielded by a shielding layer  19 . The reference numeral  18  shows a shield jacket. 
     The housing  17  comprises contacts (not shown), which receive male contacts  20  which project into a shroud  13  of the receiving connector U to be electrically connected between the cable  14  and the circuit board  12 . The housing  17  is formed with a rectangular shape in cross section, the whole outer wall of which is shielded by a shielding member  21  arranged so as to be in contact with the shield jacket  18  of the cable  14 . Here, the shield jacket may also partially cover the outer wall. 
     A plurality of contact springs (elastic contact members)  22  are provided on one surface and on the other opposing surface of the shielding shell  21  near the front edge of the shielding shell  21  of the housing  17 , for example, by cut and raised processing. The contact springs  22  can make elastic contact with and be connected electrically to a shielding case  23 A (shielding member) of the shroud  13 , when the connector  11  is inserted into the shroud  13 . Here, the shielding case  23 A is not limited to being cylinder-shaped and can be U-shaped or L-shaped in cross section. 
     The shroud  13  is box-shaped, and a plurality of male contacts  20  are provided in the bottom wall  13 A of the shroud  13 . One side of each male contact  20  projects inside the housing  17  and the other side is inserted into a through hole  12 A of the circuit board  12 . 
     A shielding case  23 A is installed in the shroud. The shielding case  23 A is pipe-shaped with a rectangular cross section, as shown in FIG. 4, which is removably inserted into the shroud  13  to cover the inner wall of the shroud  13 . Engaging parts  24  are formed extending from each of a pair of the side walls at the ends near the circuit board  12  of the shielding case  23 A. These engaging parts  24  are inserted into slits S formed in the bottom wall  13  A of the shroud  13 . 
     Pins (grounding parts, extending parts) P are provided in the engaging parts  24 , through holes  12 B connected electrically to a grounded layer (not shown) are formed in the circuit board  12  corresponding to those pins. The pins P are pushed into the through holes  12 B. Here, on insertion, using connection by means of pressing in or soldering, or soldering to the surface of the circuit board  12 , or combinations thereof are possible. Four pins in all are formed in this embodiment, but any number of pins can be formed. Pins P can be formed from extensions of the engaging parts  24 . 
     According to the embodiment described above, the shielding shell  21  of the connector  11  is electrically connected to the shielding case  23 A in the shroud  13  and the cable  14  can be reliably grounded to the circuit board  12  through the pins P formed in the shielding case  23 A, so that a conductive panel is unnecessary and the shielding layer  19  of the cable  14  can be reliably grounded at low impedance even in parts in which a conductive panel and attachments are not provided. Electromagnetic waves going to the wires  16  from outside or electromagnetic waves coming out of wires  16  can be reliably shielded by the shielding shell  21  and the shielding case  23 A. 
     Because contact springs  22  are provided in the shielding shell  21  in the housing in the connector  11 , the springs  22  do not make contact with the end of the shroud  13  when the connector  11  is inserted to the shroud  13 , which is different from the case in which contact springs are provided at the front end of the connector  11 , thereby the contact springs  22  are not deformed or damaged as a result of making contact with the end of the shroud  13 . 
     The housing  17  is received inside the shroud  13  when the connector  11  is inserted into the shroud  13 . At this time, the housing  17  and the shroud  13  press each other with rather large elastic force exerted by the contact springs  22  so that poor grounding between the housing  17  and the shroud  13  is prevented. Therefore, such a structure with low impedance is very effective as a reliable measure against EMI. Additionally, poor grounding is be avoided even when connection between the connector  11  and the shroud  13  is somewhat unstable, because the housing  17  is pressed from both sides. 
     Additionally, because grounding is performed through the pins P projecting out of the bottom  13 A of the shroud  13 , installation of the shroud  13  in the circuit board  12  is achieved at the same time with grounding, so that the number of operations can be decreased as compared with the prior art. This structure is very useful even when shrouds  13  are fabricated at high density in a row, because the springs for contacting  22  are arranged inside the shroud  13  without the projection of any members out of the shroud  13 . 
     Next, a second embodiment is described with reference to FIG.  5 . In this embodiment, the male contacts  20  are provided in advance in the circuit board  12 , by means of which the shroud  13  with the shielding case  23 A is installed on the circuit board  12 . Also in this embodiment, the pins P are formed in the shielding case  23 A and are inserted into the through hole  12 B of the circuit board  12 . The reference numeral  13 D shows penetrating holes for the male contacts  20 . As a result of such a structure, also in this embodiment, as in the first embodiment, a conductive panel and attachments are unnecessary, the contact springs are not damaged nor deformed, and the connector  11  can be reliably connected even when the shroud  13  are arranged at high density on the circuit board  12 . 
     Here, as shown in the drawing, the side walls  13 B of the shroud  13  do not interfere with the standing position of the male contacts  20 . However, in the case in which the side walls  13 B of the shroud can not be arranged between the male contacts for neighboring shrouds, due to the male contacts  20  being provided at a higher density on the circuit boards  12 , receiving holes (not shown) may be formed from the bottom wall  13 A in the side walls  13 B of the shroud and the male contacts  20  for the neighboring shrouds are received in these holes. In this case, needless to say, the male contacts  20  for the neighboring shrouds, received in the holes, are not concerned with transmission of signals. 
     In the following, a third embodiment is described with reference to FIG.  6 . Basic structures in this embodiment are the same as those in the first embodiment on the points that, for example, the shield shell  21  is provided in the housing  17  of the connector  11  and the shielding case  23 A is provided in the shroud  13 . In this embodiment, contact springs (elastic contact members)  27  are formed in the shielding case  23 A, for example, by cut-and-raised processing, instead of the contact springs being provided in the shielding shell  21 . 
     Since the contact springs  27  are provided in the shroud  13  in this embodiment, there is another advantage in addition to the advantages of the first embodiment, that is, the possibility of damage of the contact springs  27  on the insertion of the connector  11  is decreased more than when the contact springs are provided in the connector  11  as in the first embodiment. This embodiment can be applied to the structure of second embodiment shown in FIG.  5 . 
     In the following, a fourth embodiment is described with reference to FIG.  7 . In this embodiment, in addition to the structures of the first embodiment, a part of the shielding case  23 A positioned between an engaging part  24  of the shielding case  23 A and the pins P is extended, and this extended part (grounding part, extensions) N is put between the shroud  13  and the circuit board  12 . This embodiment can be applied to the second and third embodiments. The extended part can be attached, for example, by means of soldering or pressing in. A structure in which the engaging part  24  is directly inserted into the circuit board  12  without pins P can also be adopted. 
     According to this embodiment, in the case that the extended part N is fixed by means of soldering, grounding is achieved more reliably, because, in addition to grounding by the through hole  12 B for the pins P, the contact area with the grounding layer in the circuit board  12  increases. In the case of pressing in, because the pins P are pushed through the extended part N positioned next to the pins P, the process of pushing of the pins P into the circuit board  12  can be performed smoothly 
     In the following, a fifth embodiment is described with reference to FIGS. 8 and 9. In this embodiment, the connector  11  and the shroud  13  in the first embodiment become engaged and they are locked to each other by means of a locking member  28 . There are two shrouds  13  arranged in the case shown in FIG.  9 . The locking member  28  comprises an arm  29 , the center of which is supported in the cover  15  of the connector  11 . A pressed part  30  is provided in the edge near the cable of the arm  29 , and an engaging part  31  is provided in the other edge of the arm  29 . 
     A indentation  32  for engagement with the engaging part  31  is formed in the receiving part  33  of the shroud  13 . The arrangement of the engaging part  31  and the indentation  32  can be reversed. The engaging part  31  does not project beyond the outer wall of the shroud  13  when the engaging part  31  engages the indentation  32  in the receiving part  33 . A hollow  34  for release is formed at a position opposite the receiving part  33  in the neighboring shroud  13  to ensure a space for opening and closing of the engaging part  31 . In the figure, the same reference numerals have been given for parts which are analogous to those shown in the first embodiment, and their description shall be omitted. 
     According to the embodiment described above, the connector  11  can be surely locked to the shroud  13  if the engaging part  31  engages the indentation  32  by means of the elastic force produced by the arm  29  when the connector  11  is inserted into the shroud  13 . The locking member  28  does not interfere with the neighboring shroud  13  because the engaging part  31  does not project beyond the outer wall of the shroud  13  when in a locked condition. The opening and closing of the engaging part  31  is not effected by the neighboring shroud  13  because the hollow  34  for release is provided at a position opposite the receiving part  33  in the neighboring shroud  13  to ensure a space for opening and closing of the engaging part  31 . In the figure, the contact springs  22  are provided in the shielding shell  21 , but an alternative arrangement, in which contact springs  27  can be provided in the shielding shell  23 A, can be adopted. 
     Also in this embodiment, a conductive panel and attachment are unnecessary, contact springs are not damaged, and the connector  11  can be reliably connected even when the shrouds  13  are arranged at high density in rows and columns. In this case too, the locking member  28  does not interfere with the neighboring shroud  13 . Additionally, the locking member  28  does not obstruct grounding by the pins P. 
     A shielding plate  35 A which is a main part of a sixth embodiment is shown in FIG.  10 . The shielding case  23 A is provided in the shroud  13 , but a pair of plate-like shielding plates (shielding members)  35 A can be provided instead of the shielding case  23 A. Three engaging parts  24  are formed in the shielding plate  35 A, and a pair of pins P which are inserted into through holes (not shown) in a circuit board are provided in the engaging parts  24 . It is possible to provide only one shielding plate  35 A. 
     In this embodiment, in addition to the advantages of the embodiment described above, cost reductions can be achieved by using the shielding plate  35 A in comparison with use of the shielding case. Instead of shielding by a case-shaped shielding such as the shielding case  23 A, if the wires  16  (connecting part) of the cable  14  can be covered using both shielding plate  35 A and shielding plate  23 A, there are no negative effects on the shielding. 
     The case in which a conductive panel E is used for grounding is described in FIGS. 11 to  15 . In the figures, the same reference numerals have been given for parts which are analogous to those shown in the embodiments described above, and their description shall be omitted. 
     FIGS. 23 to  15  show a seventh embodiment of this invention. In this embodiment, the connector  11  is inserted through the conductive panel E into the shroud  13  provided in the circuit board  12 . Basic structures in this embodiment are the same as those in the first embodiment on the points that, for example, in the connector  11 , the cable  14  is supported by the cover  15 , and the housing  17  which holds the wires is provided at the front edge of the connector  11 . 
     The shroud  13  of the receiving connector U which receives said connector  11  is the same as that in the first embodiment, the A shielding case  23 B is set in the shroud  13 . The shielding case  23 B is pipeshaped with a rectangular cross section as shown in FIG. 13, which is removably inserted into the shroud  13  to cover the inner wall of the shroud  13 . Three engaging parts  24 , which are inserted into slits S formed in the bottom wall  13 A of the shroud  13 , are formed at three locations extending from each of a pair of one wall and an opposing wall of the shielding case  23 B, near the circuit board. On the other hand, three grounding springs  25 , which are put between the opening and the conductive panel E and make elastic contact with a peripheral part of an opening K of the conductive panel E, are provided at each of three locations on each of said one wall and said opposing wall of the shielding case  23 B, near the connector  11 . 
     Cut-out parts  13 C, (FIG. 15) which are provided with the grounding springs  25 , are formed in the opening of the shroud  13 . The cut-out parts  13 C make a space between the opening of the shroud  13  and the conductive panel E to be small while keeping elastic force due to the grounding springs  25  sufficient. The grounding springs  25  extend outside along a direction parallel to the opening of the shielding case  23 B and then bend inside with a U-shape, as shown in FIG.  13 . However, the grounding springs  25  are not limited to the shape described above, and, for example, can be shaped as shown in FIG.  17 . The grounding springs  25  may be provided in only one side of the shroud  13 . The size of the grounding springs  25  is almost the same as the wall thickness of the shroud  13  so that the grounding springs  25  do not interfere with the neighboring shrouds  13 . 
     The conductive panel E comprising the opening K, through which the connector  11  penetrates, is provided between the connector  1  land the shroud  13  The conductive panel E is supported by a unit including the circuit board  12  and makes electrical connection between the shielding shell  21  in the connector  11  and the shielding case  23 B in the shroud  13 . 
     According to the embodiment described above, because the shielding shell  21  in the connector  11  and the shielding case  23 B in the shroud  13  are electrically connected to each other in the shroud  13  by means of the contact springs  22  when the connector  11  is inserted into the shroud  13  through the opening K of the conductive panel E, the shielding layer  19  of the cable  14  is electrically connected with high reliability to the conductive panel E which makes elastic contact with the grounding springs  25  provided in the shielding case  23 B. 
     If the connector  11  is inserted into the opening K of the conductive panel E when the connector  11  is inserted, the connector  11  can be surely inserted into the given position of the shroud  13 . The grounding springs  25  are not damaged or deformed when the connector  11  is inserted into the shroud  13  because the grounding springs  25  are positioned behind the rear side of the conductive panel E and this is different from the prior art in which the grounding springs  25  are damaged and deformed because they are provided at the front end of the connector  11 . 
     Electromagnetic waves going to the wires  16  from outside or electromagnetic waves coming out of the wires  16  can be reliably shielded by the shielding shell  21  and the shielding case  23 A, when the connector  11  is inserted into the shroud  13 . 
     The housing  17  is received inside the shroud  13  when the connector  11  is inserted into the shroud  13 . At this time, the housing  17  and the shroud  13  press each other with rather large elastic force due to the contact springs  22  so that poor electric connection between the housing  17  and the shroud  13  is prevented. Therefore, such a structure with low impedance is very effective as a reliable measure against EMI. Additionally, poor electric connection at the connecting area is avoided even when connection between the connector  11  and the shroud  13  is somewhat unstable, because the housing  17  is pressed from both sides. The conductive panel E which is fixed in the circuit board  12  or the shroud  13  is able to secure elastic contact with the circuit board  12  or the shroud  13  through the grounding springs  25  so that poor contact at the contact point does not occur. 
     Because the contact springs  22  are positioned within the shroud  13  and the grounding springs  25  do not project out of the outer wall of the shroud  13 , the shrouds  13  do not interfere each other even when the shrouds  13  are packaged at high density in a row. The structure shown in FIG. 5 can be applied to this seventh embodiment, and the structure shown in FIG. 6, that is, the structure in which the springs  27  are provided in the shielding case  23 A, can be applied to this seventh embodiment. 
     In the following, the eighth embodiment is described using FIGS. 14 and 15. In this embodiment, the connector  11  and the shroud  13  in the embodiment become engaged and they are locked to each other by means of a locking member  28 . In the FIG. 15, two shrouds  13  are arranged. The locking member  28  comprises an arm  29 , the center of which is supported in the cover  15  of the connector  11 . A pressed part  30  is provided at the end near the connector  11  of the arm  29 , and an engaging part  11  is provided at the end near the shroud  13  of the arm  29 . 
     On the other hand, an indentation  32  for engagement with the engaging part  11  is formed in the receiving part  33  of the shroud  13 . The arrangement of the engaging part  31  and the indentation  32  can be reversed. The engaging part  31  does not project beyond the outer wall of the shroud  13  when the engaging part  31  engages the indentation  32  in the receiving part  33 . A hollow  34  for release is formed at a position opposite the receiving part  33  in the neighboring shroud  13  to ensure a space for opening and closing of the engaging part  31 . A cut-off area K 1  for release of the locking member  28  is formed in an opening K of the conductive panel E. In the shielding case  23 B installed within the shroud  13 , there are no grounding springs  25  in the side to which the locking member  28  is provided. 
     In the drawing, the same reference numerals have been given for parts which are analogous to those shown in the first embodiment, and their description shall be omitted. 
     According to the embodiment described above, the connector  11  can be securely locked to the shroud  13  if the engaging part  31  engages the indentation  32  by means of the elastic force produced by the arm  29  when the connector  11  is inserted into the shroud  13  from the opening K of the conductive panel E. The locking member  28  does not interfere with the neighboring shroud  13  because the engaging part  31  does not project beyond the outer wall of the shroud  13  when in the locked condition. The opening and closing of the engaging part  31  is not effected by the neighboring shroud  13  because the hollow  34  for release is provided at a position opposite the receiving part  33  in the neighboring shroud  13  to ensure space for opening and closing of the engaging part  31 . In the figure, the contact springs  22  are provided in the shielding shell  21 , but an alternative arrangement, in which contact springs  27  can be provided in the shielding shell  23 B, can be adopted. 
     Grounding can be surely achieved by means of the grounding springs  25  arranged in the rear side of the conductive panel E. In this figure, the grounding springs  25  are provided at only one side, but poor grounding resulting from the insertion does not come about because the conductive panel E is securely fixed to the shroud  13  or to the circuit board  12  and the fixation is not effected by the insertion of the connector  11 . The contact springs  22  and the grounding springs  25  are not damaged or deformed when the connector  11  is inserted. The connector  11  can be reliably connected even when shrouds  13  are mounted at high density in rows and columns on the circuit board  12 . At this time, the locking member  28  does not interfere with the neighboring shrouds. 
     FIG. 16 shows the shielding plate  35 A which is the main part of a ninth embodiment. A pair of plate-type shielding plates (shielding member)  35 B are provided, instead of the shielding cases  23 B provided in the shroud  13  in the preceding embodiments. Three engaging parts  24  are formed in one side of the shielding plates  35 B, and grounding springs  25 , the same as those in the embodiments described above, are provided in the other side. 
     The grounding springs  25  may be shaped to be raised obliquely from the edge of shielding plates  35 B and parts of the grounding springs  25  may be shaped to be arched. It is possible to provide only one shielding plate  35 B. In this case, the side must be the same side as that provided with the contact springs in the shielding shell. 
     In this embodiment, in addition to the advantages of the embodiments described above, the structure is simpler and cost reductions can be achieved by using the shielding plate  35 B compared with the use of the shielding case. Instead of shielding by a case-shaped shielding such as the shielding case  23 B, if the wires  16  (connecting part) of the cable  14  can be covered using both shielding plate  35 B and shielding plate  23 B, there arc no negative effects on the shielding. 
     Another embodiment for assembling the shroud  13  in the embodiment described above is shown in FIGS. 18 and 19. In this embodiment, through holes  13 D, which are formed in the bottom of the shroud  13 , are sized to be penetrated loosely by MALE connectors to which are provided on the circuit board  12 . The side from which the male contacts  20  are inserted into the through holes  13 D is formed to be wider than the other side. Built-up parts  40  are formed on the other side of the through holes  13 D. The inner size of the opening of each built-up part  40  become smaller than that in the rest of the through holes  13 D because the opening of the built-up part  40  is deformed when the shielding case  23 B is installed as shown in FIG.  19 . 
     On the other hand, a bottom wall  23 C is formed in the shielding case  23 A or  23 B installed in the shroud  13 . Holes  41 , into which the built-up parts  40  are inserted, are formed in the bottom wall  23 C. For example, when the male contacts  20  are inserted through holes  13 D with the built-up parts  40  set into the holes  41 , the size of the opening in each built-up part  40  become larger and thereby the shielding case  23 A or  23 B, the shroud  13  and the male contacts  20  are integrally fixed. The bottom walls  23 C are made of double-bent metal and are thereby formed thickly. The reference numeral  14  shows engaging parts. 
     By applying the structure described above to the preceding embodiments, the number of installation operations can be decreased, because the shielding case  23 A or  23 B, the shroud  13  and the male contacts  20  can be integrally fixed. In the description above, a case in which the shielding case  23 A or  23 B is used is described, but if the bottom walls are formed in the shielding plates  35 A or  35 B in the embodiment above, the structure described above can be applied. 
     The shrouds  13  in the embodiment above can be used both in cases with and without the conductive panels E, the shielding case  23 A or  23 B can be installed selectively within the shroud  13 . In the case with the conductive panels E, the shielding case  23 B grounded to the conductive panels E is installed within the shroud  13  which is fixed to the circuit board  12 . On the other hand, in the case without the conductive panels E, the shielding case  23 A grounded to the circuit board  12  is installed within the shroud  13  which is fixed to the circuit board  12 . Thereby, the same shroud can be used both in cases with and without the conductive panels E by only exchanging the shielding member. The shielding cases can be installed by a simple operation in which the engaging parts  24  are inserted into the slits S in the bottom wall  1   3 A in the shroud  13 . 
     The present invention is not limited to the embodiments described above. For example, although a structure in which the whole surface of the shielding shell  21  is exposed has been described with reference to FIG. 2, a structure in which only the parts for the contact springs  22  in the surface of the shielding shell  21  are exposed on the shielding shell  21  and the other parts are covered with insulating materials, can be used. 
     As described above, the invention has an advantageous effect by which contact springs can be arranged in areas in which a conductive panel and attachments are not arranged because the shielding member in the shielded connector can make reliable electrical connection with the shielding member in the receiving connector within the shroud, and the shielding layer surrounding the cable can be reliably grounded to the circuit board through the grounding parts in the shielding member in the receiving connector. The invention has an advantageous effect by which the contact springs are not damaged when the shielded connector is connected to receiving connector because the contact springs can be arranged at position other than the front end of the shielded connector. This invention has an advantageous effect by which the connection between a shielded connector and a receiving connector can be surely achieved even when receiving connectors are mounted at high density because the shielded connectors and the receiving connectors are connected to each other by inserting the shielded connectors into the receiving connectors. The invention has an other advantageous effect by which, when the shielded connector is inserted into the shroud in the receiving connector, the shielding member in the connector can make reliable electrical connection with the shielding member in the receiving connector by means of contact springs and the shielding layer surrounding the cable can be reliably grounded to the conductive panel due to the elastic contact between the grounding springs of the shielding layer in the receiving connector and the conductive panels, and thereby such a structure is very effective for a reliable measure against EMI. This invention has an advantageous effect such that the grounding springs are not deformed or damaged when the connector is inserted because the grounding springs make elastic contact with the rear side of the conductive panel and does not project outward. 
     The invention further has an advantageous effect by which contact springs can be arranged in areas in which a conductive panel and attachments are not arranged because both shielding members can make reliable electrical connection with each other by means of contact springs provided in the shielded connector and the shielding layer surrounding the cable can be reliably grounded to the circuit board through the grounding parts formed in the shielding member in the receiving connector. This invention has an advantageous effect by which the contact springs are not damaged when the shielded connector is connected to the receiving connector because the contact springs can be arranged not at the front end of the shielded connector. 
     The invention has an advantageous effect by which contact springs can be arranged in areas in which a conductive panel and attachments are not arranged because both shielding members can make reliable electrical connection with each other by means of contact springs provided in the shielded connector and the shielding layer surrounding the cable can be reliably grounded to the circuit board through the grounding parts formed in the shielding member in the receiving connector. This invention has an advantageous effect by which the contact springs are not damaged when the shielded connector is inserted into the receiving connector because the contact springs are not provided in the shielded connector. 
     The invention described has an advantageous effect by which the number of operations for installation can be reduced because the extensions can be grounded to the circuit board whenever the shroud is installed in the circuit board. 
     The invention described in claim  6  has an advantageous effect by which cost reductions can be achieved by the simplification in the structure of the shielding member, in addition to the advantageous effect described above. 
     The invention described has an advantageous effect by which cost reductions can be achieved because grounding can be achieved by means of the minimum number of grounding spring in addition to the advantageous effect described above. This invention has an advantageous effect by which, even though the grounding springs  25  are provided at only one side, grounding through the shielding member in the shroud is not affected from such a structure and poor grounding resulting from the insertion does not come about because the conductive panel is fixed in advance before the shielded connector is inserted. 
     The invention described has advantageous effect by which removal of the shielded connector from the receiving connector when the shielded connector is inserted to the receiving connector is prevented because the shielded connector and the receiving connector can be reliably connected. 
     The invention described has an advantageous effect by which the grounding can be grounded more reliable because the shielding member in the shroud can be grounded both to the conductive panel and the circuit board. 
     The invention described has an advantageous effect by which the shielded connector can be reliably grounded whenever the shielded connector is inserted into the receiving connector because the shielding layer surrounding the cable can make reliable electrical contact with the circuit board or the conductive panel through the shielded connector and the receiving connector.