Abstract:
In a connector, an insulator has a mount portion. Signal and ground contacts are held by the insulator, each having a terminal portion placed on the mount portion. A shell member surrounds the insulator. The mount portion includes a groove portion corresponding to the terminal portion of the ground contact. The shell has a terminal portion inserted into the groove portion and clamped between the terminal portion of the ground contact and a bottom of the groove portion.

Description:
This application claims priority to prior Japanese patent application JP 2004-188923, the disclosure of which is incorporated herein by reference. 
   BACKGROUND OF THE INVENTION 
   This invention relates to a connector having a plurality of contacts and suitable for use in differential transmission. 
   A connector of the type has a metal shell surrounding a plurality of contacts via an insulator. At least one of the contacts is used as a ground contact and, therefore, electrically connected to the shell. Specifically, a terminal portion of the shell is provided with a spring portion. The ground contact is elastically contacted with the spring portion. 
   However, if an external force is applied to the shell, the spring portion may be displaced. This results in unstable contact between the spring portion and the ground contact. 
   In case of a connector used for connection of a thin-wire coaxial cable, a ground connection must be made via a ground bar attached to the cable. As a result, the connector is complicated in structure. 
   SUMMARY OF THE INVENTION  
   It is therefore an object of the present invention to provide a connector in which a ground contact can reliably and stably be contacted with a shell. 
   It is another object of the present invention to provide a connector which is simple in structure and has a robustness. 
   Other objects of the present invention will become clear as the description proceeds. 
   According to an aspect of the present invention, there is provided a connector comprising an insulator having a mount portion, a signal contact held by the insulator and having a terminal portion placed on the mount portion, a ground contact held by the insulator and having a terminal portion placed on the mount portion, and a shell member surrounding the insulator, the mount portion including a groove portion corresponding to the terminal portion of the ground contact, the shell having a terminal portion which is inserted into the groove portion and clamped between the terminal portion of the ground contact and a bottom of the groove portion. 

   
     BRIEF DESCRIPTION OF THE DRAWING  
       FIG. 1  is a rear perspective view of a connector according to an embodiment of the present invention; 
       FIG. 2  is a front perspective view of the connector illustrated in  FIG. 1 ; 
       FIG. 3  is an exploded perspective view of the connector illustrated in  FIG. 1 ; 
       FIG. 4  is a front perspective view of the connector illustrated in  FIG. 1  in a state where a shell is removed therefrom; 
       FIG. 5  is a rear perspective view of the connector illustrated in  FIG. 1  in the state where the shell is removed therefrom; 
       FIG. 6  is a sectional view taken along a line VI—VI in  FIG. 5 ; 
       FIG. 7  is a front perspective view of a mating connector to be connected to the connector illustrated in  FIG. 1 ; and 
       FIG. 8  is a rear perspective view of the mating connector illustrated in  FIG. 7 . 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring to  FIGS. 1 to 6 , description will be made of a connector according to an embodiment of the present invention. 
   The connector illustrated in  FIGS. 1 to 6  is a cable connector  1  to be connected to a cable (not shown). The cable connector  1  comprises a plurality of contacts (including signal contacts and ground contacts)  2 , an insulator  3  holding the contacts  3 , a lower shell  4 , and an upper shell  5 . Each of the contacts  2  is formed by pressing a metal plate and has a contacting portion  2   a  and a terminal portion (soldering portion)  2   b.  The lower shell  4  comprises a main body  4   a  and a pair of lock springs  4   b  integrally formed on opposite ends of the main body  4   a.    
   The insulator  3  is made of a resin material and has a fitting portion  3   a  and a main body portion  3   b.  The fitting portion  3   a  is provided with a plurality of contact grooves  3   c.  A plurality of contact holes  3   d  extend from the contact grooves  3   c  towards the main body portion  3   b,  respectively. Each contact hole  3   d  has an exit opened on the side of the main body portion  3   b  and faced to a mount portion or a platform  3   e  serving as a wiring portion. 
   The fitting portion  3   a  has a pair of guide posts  3   f  integrally formed on left and right front ends thereof to guide fitting of the cable connector  1  and a mating connector (which will later be described). Each guide post  3   f  has a lock groove  3   g  formed on its outer side surface. The main body portion  3   b  has a pair of insertion holes  3   h  formed on left and right rear ends thereof to receive the lock springs  4   b  to be inserted therein, respectively. The insulator  3  is provided with a plate portion  3   q  facing the mount portion  3   e  to form a through hole  3   i  therebetween. The through hole  3   i  extends from the main body portion  3   b  to a lower surface of the fitting portion  3   a  to allow passage of a ground connecting portion  4   a   3  of the lower shell  4 . 
   The insulator  3  has a pair of levers  3   k  of a cantilevered shape integrally formed on left and right side portions  3   j,  respectively. Each lever  3   k  has an end portion  3   k   1  provided with a groove portion  3   k   2  and a lever operating portion  3   k   3 . The main body portion  3   b  is provided with stepped portions  3   m  formed on upper and lower surfaces on left and right sides thereof. 
   The lower shell  4  is formed by pressing a metal plate and has the main body  4   a  and the lock springs  4   b  arranged on left and right sides thereof. The main body  4   a  has a rear end provided with a cable-ground connecting portion  4   a   1  formed by drawing at a height corresponding to the size of the cable. The main body  4   a  is provided with a plurality of terminal portions  4   a   2  extending from the cable-ground connecting portion  4   a   1  towards a front end thereof. The main body  4   a  has the ground connecting portion  4   a   3  for the mating connector and a pair of press-fit portions  4   a   4  formed on left and right sides thereof to be press-fitted to the insulator  3 . 
   The main body  4   a  has a pair of vertical wall portions  4   a   5  formed on left and right sides thereof. Each of the vertical wall portions  4   a   5  has a frame-like lever protecting portion  4   a   6 . A lock spring  4   b  extends from a rear end face  4   a   5   a  of each vertical wall portion  4   a   5  in parallel to the vertical wall portion  4   a   5 . Each lock spring  4   b  has a lock engaging portion  4   b   1  formed on its forward end. 
   The cable connector is assembled in the following manner. 
   The lock springs  4   b  of the lower shell  4  are inserted into the insertion holes  3   h  of the insulator  3 , respectively. The lock engaging portions  4   b   1  protrude outward from the lock grooves  3   g  of the guide post  3   f.  At this time, the vertical wall portions  4   a   5  of the main body  4   a  are inserted into a pair of grooves  3   n  formed on left and right inner surfaces of the main body portion  3   b,  respectively. The lever protecting portions  4   a   6  are coupled with the stepped portions  3   m.  A pair of slits  4   a   6   a  of the lever protecting portions  4   a   6  are fitted to the groove portions  3   k   2  of the levers  3   k.  Thus, the levers  3   k  are prevented from being excessively deformed. The main body  4   a  passes through the through hole  3   i  of the insulator  3  and fixed to the insulator  3  by the press-fit portions  4   a   4 . 
   The terminal portions  4   a   2  are fitted to a plurality of groove portions  3   p  formed on the insulator  3  and disposed at the bottom of the groove portions  3   p.  When the contacts  2  of the cable connector  1  are press-fitted into the contact holes  3   d  of the insulator  3 , respectively, the contacting portions  2   a  are disposed on the contact grooves  3   c  and the terminal portions  2   b  are disposed on the mount portion  3   e  of the insulator  3 . Those of the contacts  2  which are disposed in the groove portions  3   p  surmount upper surfaces of the terminal portions  4   a   2  of the lower shell  4 , which are already fitted into the groove portions  3   p,  and are electrically connected to the terminal portions  4   a   2  to serve as ground contacts. 
   Thereafter, the upper shell  5  is overlaid on an upper surface of the insulator  3 . Engaging portions  5   a  and  5   b  formed by bending on front and rear ends on left and right sides of the upper shell  5  are fixed to the insulator  3  and the lower shell  4 , respectively. At this time, a plurality of spring portions  5   c  formed by cutting on an upper surface of the upper shell  5  are contacted with a metal member for common connection of ground portions in case where a thin-wire coaxial cable is used. The spring portions  5   c  are also adapted to be electrically connected to the cable-ground connecting portion  4   a   1  of the lower shell  4  owing to elasticity and to the contacts  2  serving as the ground contacts through the terminal portions  4   a   2 . 
   Referring to  FIGS. 7 and 8 , description will be made of the mating connector  11  to be connected to and disconnected from the cable connector  1 . 
   The mating connector  11  comprises a plurality of contacts  12 , an insulator  13  holding the contacts  12 , and a shell  14 . Each of the contacts  12  is formed by pressing a metal plate and has a contacting portion  12   a  and a terminal portion (soldering portion)  12   b.  The insulator  13  is made of a resin material and has a pair of guide holes  13   a  formed on left and right sides thereof to receive the guide posts  3   f  of the cable connector  1  to be inserted therein, respectively. 
   The shell  14  is formed by a metal plate into a generally rectangular frame and has an upper surface portion  14   a,  a lower surface portion  14   b,  and a pair of left and right side surface portions  14   c.  The lower surface portion  14   b  is provided with a plurality of soldering portions  14   b   1  formed on its front side and two soldering portions  14   b   2  formed on its rear side. Each of the side surface portions  14   c  is provided with a soldering portion  14   c   1 . 
   The cable connector  1  and the mating connector  11  are connected to and disconnected from each other in the following manner. 
   The guide posts  3   f  of the cable connector  1  are inserted into the guide holes  13   a  of the mating connector  11 . Then, the lock engaging portions  4   b   1  of the lower shell  4  of the cable connector  1  are engaged with lock holes (not shown) formed on the opposite side surface portions  14   c  of the shell  14  of the mating connector  11 , respectively. Consequently, the cable connector  1  and the mating connector  11  are fixed in a fitted state. At this time, the contacting portions  2   a  of the contacts  2  of the cable connector  1  are connected to the contacting portions  12   a  of the contacts  12  of the mating connector  11 . 
   In order to disconnect the cable connector  1  from the mating connector  11 , the lever operating portions  3   k   3  of the levers  3   k  of the cable connector  1  are held by operator&#39;s fingers and pushed inward. Then, the levers  3   k  push protruding portions  4   b   2  of the lock springs  4   b  inward so that the lock springs  4   b  are elastically deformed. As a consequence, the lock engaging portions  4   b   1  are pulled out from the lock holes of the mating connector  11  to be unlocked. Thereafter, the cable connector  1  is disconnected from the mating connector  11 . 
   While the present invention has thus far been described in connection with the preferred embodiment thereof, it will readily be possible for those skilled in the art to put this invention into practice in various other manners. Although description is made about the connector including a plurality of signal contacts and a plurality of ground contacts, the connector may include only a single signal contact and a single ground contact. In this event, it is a matter of course that the mount portion has a single groove portion and that the lower shell has a single cable-ground connecting portion.