Abstract:
An electrical connector having a shielding shell. The shielding shell disposed about an insulating housing mounted on a circuit board. The shielding shell including a first shell and a second shell. The first shell having a first side wall. The first side wall having a first locking member. The second shell having a second side wall. The second side wall having a second locking member corresponding to the first locking member. When the second locking member engages the first locking member the first side wall overlaps with the second side wall to prevent movement of the second shell in a vertical and horizontal direction in relation to the first shell.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to an electrical connector and, more particularly, to an to an electrical connector having a shielding shell for blocking external electromagnetic waves. 
     DESCRIPTION OF THE PRIOR ART 
     Various types of electrical connectors, such as cellular telephones, are provided with a metallic shielding shell to protect signal paths of the connector from external electromagnetic waves. The connector has an insulating housing having electrical contacts disposed therein. The shielding shell covers an outer periphery of the insulating housing and is generally formed by punching and bending a metal plate into a cubical or cylindrical shape. The shielding shell has a seam at a position where ends of the metal plate abut each other. Because the ends of the metal plate simply abut each other, if an excessive external prying force is applied to the shielding shell when the connector is mated to a mating connector, the ends of the metal plate may spread causing the shielding shell to deform. 
     In an effort to alleviate this problem, Japanese Unexamined Patent Publication 2001-126819 teaches a shielding shell formed from a metal plate wherein ends of the metal plate overlap and are fastened to each other. One end of the metal plate is folded upward to form an insertion supported portion. Both sides of an other end of the metal plate are cut-out and folded to form fastening portions. The ends are overlapped and fastened by the fastening portions to fix the ends of the metal plate to each other. This shielding shell provides resistance against deformation by prying forces applied in a direction perpendicular to the vertical direction, that is, in the direction perpendicular to a plane of the overlapped ends of the metal plate. However, the shielding shell may still be deformed when a prying force is applied in a direction parallel to the plane of the ends of the overlapped metal plate, because the ends of the shielding shell can still shift along that plane. 
     It is therefore desirable to develop a shielding shell that will resist deformation due to prying forces and external forces in any direction. 
     SUMMARY OF THE INVENTION 
     The invention relates to a shielding shell for an electrical connector. The shielding shell includes a first shell and a second shell. The first shell has a first shell end. The first shell end having a first locking member. The second shell having a second shell end. The second shell end having a second locking member corresponding to the first locking member. When the second locking member engages the first locking member the first shell end overlaps with the second shell end to prevent movement of the second shell end in a vertical and horizontal direction in relation to the first shell end. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view from a side of an engagement opening of an electrical connector having a shielding shell according to the present invention. 
     FIG. 2 is an exploded perspective view of the electrical connector of FIG.  1 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIGS. 1-2 show an electrical connector  1  having an insulating housing  2  covered by a shielding shell  8 . As shown most clearly in FIG. 2, the housing  2  has a horizontal engagement rib  26  and a cylindrical protrusion  28 . A plurality of contacts  4  are arranged on the engagement rib  26  and are separated from each other by a plurality of walls  26   a . The cylindrical protrusion  28  houses a coaxial contact  6 . The coaxial contact  6  has a central contact  6   a  and an arcuate outer contact  6   b . Steps  32  are formed on both sides of a bottom  30  of the housing  2 . A plate  23  that abuts a rear edge  21  of a lower shell  8   b  is formed on the bottom  30  of the housing  2  and extends in a lengthwise direction thereof (the horizontal direction in FIG.  2 ). Holes  36  are formed at both sides of an upper portion of the housing  2 . 
     The shielding shell  8  has an upper shell  8   a  and the lower shell  8   b . The upper shell  8   a  has an upper wall  14  and downwardly extending side walls  12  at both edges thereof. As shown most clearly in FIG. 2, cutouts  41 ,  43 , are formed at both sides of a rear edge of the upper wall  14 . The cutouts  41 ,  43  have downwardly extending engagement pieces  57 . The engagement pieces  57  are press-fit into the holes  36  of the housing  2  when the housing  2  and the upper shell  8   a  are assembled to fix the housing  2  and the upper shell  8   a  to each other. A pair of engagement apertures or first locking members  10  is formed on each of the side walls  12  of the upper shell  8   a . The engagement apertures  10  are separated from each other and are positioned along an insertion/removal direction of the connector  1 . 
     A top guide piece  44  is formed at a forward edge of the upper wall  14  and extends from one side wall  12  to the other side wall  12 . The top guide piece  44  guides a mating connector (not shown) into engagement opening  24 . As shown in FIGS. 1 and 2, rectangular openings  42  are formed in the upper wall  14  and the side walls  12 ,  12 . The rectangular openings  42  engage locking arms (not shown) of the mating connector (not shown). The locking arms (not shown) of the mating connector (not shown) engage with the openings  42  to lock the connectors to each other. 
     As shown most clearly in FIG. 1, tongue pieces  40  formed from U-shaped slits  38  are positioned in the vicinity of both edges of the upper wall  14 . The tongue pieces  40  extend forward (the direction toward the engagement opening  24  or the foreground in FIGS. 1 and 2) and downward. The tongue pieces  40  act as contact pieces for electrical grounding and contact a shielding shell (not shown) of the mating connector (not shown) that is received in the engagement opening  24 . Although the tongue pieces  40  are described as extending forward in this embodiment, the tongue pieces may alternatively be formed to extend backward. 
     Each of the side walls  12  has an engagement protrusion  46 . The engagement protrusion  46  is integrally formed with the upper shell  8   a  and has a tapered shape. Barbs  46   a  are formed on both sides of the engagement protrusion  46 . The engagement protrusion  46  extends upward from a horizontal portion  47  that extends horizontally from an approximate center of a lower edge  12   a  of each of the side walls  12 . The vertical position of the horizontal portion  47  is such that the horizontal portion  47  is surface mountable to a circuit board (not shown) when the connector  1  is mounted thereon. The horizontal portion  47  and the engagement protrusion  46  are collectively referred to as fixing portions  45 . 
     A pair of downwardly extending legs or tines  48  are integrally formed at the lower edges  12   a  of each of the side walls  12 . The tines  48  are received in apertures (not shown) of a circuit board (not shown) and soldered thereto when the connector  1  is mounted on the circuit board (not shown). Although the tines  48  are described as extending downward, the tines  48  may alternatively be formed to extend outward so as to enable surface mounting similar to the horizontal portions  47 . 
     The lower shell  8   b  has a lower wall  20  that has upwardly extending side walls  18 . Engagement pieces  52  protrude from both sides of a rear portion of the lower wall  20 . The engagement pieces  52  are press-fit into holes (not shown) formed in the bottom  30  of the housing  2  and are engaged thereto when the shielding shell  8  and the housing  2  are assembled. A pair of latch arms or second locking members  16  is formed on each of the side walls  18  of the lower shell  8   b . The latch arms  16  incline outwardly and correspond with the engagement apertures  10  to be fixed at upper ends thereof. The distance between the side walls  18  is shorter than the distance between the side walls  12  of the upper shell  8   a  so that the side walls  18  of the lower shell  8   b  are disposed inside the side walls  12  of the upper shell  8   a  when the upper shell  8   a  and lower shell  8   b  are assembled. 
     A bottom guide piece  54  is formed at a forward edge of the lower wall  20  and extends from one side wall  18  to the other side wall  18 . Side guide pieces  56  are formed on each of the side walls  18 . The bottom and side guide pieces  54 ,  56  guide the mating connector (not shown) into the engagement opening  24 . 
     The side walls  18  have cutouts  58  corresponding to the openings  42  of the upper shell  8   a . Steps  50  are formed between the lower wall  20  and the side walls  18 . The steps  50  surround the housing  2  along the step  32  of the housing  2  when the shielding shell  8  and the housing  2  are assembled. 
     The assembly of the shielding shell  8  to the housing  2  will now be described in greater detail. The engagement pieces  57  of the upper shell  8   a  are press-fit into the holes  36  of the housing  2  to fix the upper shell to the housing  2 . The engagement pieces  52  of the lower shell  8   b  are press-fit into the holes (not shown) on the bottom  30  of the housing  2  to fix the lower shell  8   b  to the housing  2 . The side walls  18  of the lower shell  8   b  are disposed inside the side walls  12  of the upper shell  8   a  so that the side walls  12  and the side walls  18  overlap. The latch arms  16  engage with the engagement apertures  10  to fix the upper shell  8   a  and the lower shell  8   b  to each other. 
     When the latch arms  16  provided on the lower shell  8   b  engage with engagement apertures  10  provided on the upper shell  8   a , the upper and lower shells  8   a ,  8   b  are fixed so that they do not move in vertical or horizontal directions with respect to each other. When the upper shell  8   a  and the lower shell  8   b  are fixed in the vertical direction, deformation in the vertical direction is prevented when a prying force is applied in the vertical direction. When a prying force is applied in the horizontal direction, the side walls  12  of the upper shell  8   a  prevent the lower shell  8   b  form opening to prevent deformation. In addition, because the upper shell  8   a  is fixed to the circuit board (not shown), vertical as well as horizontal movement of the upper shell  8   a  becomes difficult, further preventing deformation.