Abstract:
A card edge connector assembly for connecting a pair of electrical cards to a printed circuit board includes an upper connector and a lower connector. The upper connector includes a first housing defining a first elongated mating groove along a longitudinal direction with a plurality of first contacts by two sides thereof, and a recess is defined under the first elongated mating groove. The lower connector is moveably received within said recess and includes a second housing defining a second elongated mating groove with a plurality of second contacts by two sides thereof. A metallic member is attached to the upper connector for preventing the lower connector releasing from said recess.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a card edge connector assembly, and more particularly to a stacked card edge connector assembly configured with a first connector, and a second connector floatably attached to the first connector. 
     2. Description of the Related Art 
     U.S. Pat. No. 6,126,472 issued to Choy on Oct. 3, 2000 discloses a connector assembly configured to have a lower housing and an upper housing each generally including the basic structure of the typical  50  DIMM connector housing. Each housing defines two rows of passageways on two sides of the central slot in which the corresponding module is received. A plurality of contacts are received within the corresponding passageways wherein the tail of each contact extends downward to be soldered onto the PC board on which the connector assembly is mounted. When high density and high speed transmission become a trend, alignment of those four hundreds more contacts with the corresponding solder pads or through holes become an issue. Obviously, an improved card edge connector assembly is highly desired to overcome the aforementioned problem. 
     SUMMARY OF THE INVENTION 
     Accordingly, an object of the present invention is to provide a card edge connector assembly facilitates the tails of the contacts inserting into the corresponding holes on a printed circuit board. 
     In order to achieve the object set forth, a card edge connector assembly for connecting a pair of electrical cards to a printed circuit board includes an upper connector and a lower connector. The upper connector includes a first housing defining a first elongated mating groove along a longitudinal direction with a plurality of first contacts by two sides thereof, and a recess is defined under the first elongated mating groove. The lower connector is moveably received within said recess and includes a second housing defining a second elongated mating groove with a plurality of second contacts by two sides thereof. A metallic member is attached to the upper connector for preventing the lower connector releasing from said recess. 
     Other objects, advantages and novel features of the invention will become more apparent from the following detailed description of the present embodiment when taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a card edge connector assembly in accordance with the present invention mounted on a printed circuit board; 
         FIG. 2  is an exploded perspective view of the card edge connector assembly shown in  FIG. 1 ; 
         FIG. 3  is another exploded perspective view of the card edge connector assembly shown in  FIG. 1 ; 
         FIG. 4  is an exploded perspective view of the card edge connector assembly shown in  FIG. 1 , which shows a retaining member releasing from the card edge connector assembly; 
         FIG. 5  is a perspective view of the card edge connector assembly shown in  FIG. 1 , seen from a bottom side; 
         FIG. 6  is a perspective view of the card edge connector assembly shown in  FIG. 1 , seen from a front side; and 
         FIG. 7  is a cross sectional view of the card edge connector assembly shown in  FIG. 1  along line  7 - 7   
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Reference will now be made to the drawing figures to describe a preferred embodiment of the present invention in detail. Referring to  FIGS. 1 and 2 , a card edge connector assembly  100  made according to the preferred embodiment of the present invention is provided and comprises an upper connector  1  and a lower connector  2  for respectively connecting a pair of memory modules to a printed circuit board  200  and an ejecting device  3  combining the upper and lower connectors  1 ,  2  together. 
     Referring to  FIGS. 2 and 3 , the upper connector  1  comprises a first housing  11  and a plurality of first terminals  12  mounted therein. The first housing  11  comprises an elongated first base portion  110  defining a first mating groove  112  extending along a longitudinal direction thereof and a pair of first side arms  111  disposed at opposite ends of the first base portion  110 . Each first side arm  111  defines a first and a second guiding grooves  113 ,  114  parallel to each other at an inner face thereof, and the first guiding groove  113  is coplanar to the first mating groove  112  and in communication with the first mating groove  112  so as to allow the memory module to be inserted in a horizontal manner. In addition, an opening slot  115  extends forwardly and horizontally from a rear middle portion of an outer face  119  of the first side arm  111  along a rear-to-front direction. A first sliding groove  116  runs through a top face of the first base portion  110  along a vertical direction and extends forward from the rear end of the first side arm  111 , more particularly, the first sliding groove  116  is in communication with the first mating groove  112  through an aperture defined in the first guiding groove  113 . A second sliding groove  117  which is configured as an L-shaped configuration as seen from a rear side thereof and extends forward from the rear end of the first side arm  111 . Moreover, the first housing  11  defines a recess portion  13  under the first mating groove  112  thereby making the first housing  11  in an L-shaped configuration. A cut out portion  131  is defined at an inner end of the first side arm  111  so as to broaden the recess portion  13  in the longitudinal direction. Each first terminal  12  defines a solder tail  121  extending out of a mounting face  118  of the first housing  11  and located behind the recess portion  13 . 
     Referring to  FIG. 2  to  FIG. 4 , the lower connector  2  comprises a second housing  21  with a plurality of second terminals  22  mounted therein. The second housing  21  comprises an elongated second base portion  210  defining a second mating groove  212  extending along a longitudinal direction thereof and a pair of second side arms  211  disposed at opposite ends of the second base portion  210 . A third guiding groove  213  is defined at an inner face of the second side arm  211  and runs toward the second mating groove  212 . Moreover, a third sliding groove  214 , which is in an L-shaped configuration as seen from the rear side, extends forward from a rear end of the second side arm  211  and is in communication with the second mating groove  212 . Each of the second terminals  22  defines a solder tail  221  extending out of a mounting face  215  of the second housing  21 . 
     Referring to  FIGS. 3 ,  4  and  7 , the lower connector  2  is inserted into the recess portion  13  from the mounting face  118  with the second side arms  211  received in the cut out portion  131 , and the front ends of upper and lower connectors  1 ,  2  are aligned with each other in the vertical direction. The third sliding groove  214  is located at an inner side of the second sliding groove  117  and communicates with the second sliding groove  117  in a horizontal plane. Meanwhile, the third guiding groove  213  is located behind the second guiding groove  114  and connects with the second guiding groove  114  in the rear-to-front direction. The dimension of the recess portion  13  is slightly larger than that of the lower connector  2 , therefore apertures are defined between the lower connector  2  and the upper connector  1  which allow the lower connector  2  to slightly move toward any direction. 
     Referring to  FIGS. 2-4 , the ejecting device  3  is made by stamping a metal sheet and comprises a plate like operating portion  31  and a pair of side portions  32  symmetrically arranged at opposite ends of the operating portion  31 . Each side portion  32  comprises a side plate  321  extending forward from the operating portion  31  and perpendicular to the operating portion  31 , and a first and a second positioning portion  322 ,  323  respectively extending from an upper and a lower edge of the side plate  321 . The first and second positioning portions  322 ,  323  are away from the operating portion  31  and respectively comprise a horizontal plate  324  and a vertical plate  325 / 326  which are configured as an L-shaped. A guiding plate  327  is defined at the upper edge of the side plate  321  and located adjacent to the operating portion  31 . 
     Referring to  FIG. 5-7 , the ejecting device  3  is assembled onto the first connector  2  from a rear end thereof, the guiding plate  327  is firstly inserted into the opening slot  115 , then the vertical plate  325  of the first positioning portion  322  is inserted into the first sliding groove  116  with the horizontal plate  324  covering a top face of the first side arm  111 , meanwhile the second positioning portion  323  is inserted into the second sliding groove  117 . Finally, a pair of bars  4  are respectively inserted into the rear end of the first side arm  111  for preventing the ejecting device  3  releasing from the first connector  2 . As the second positioning portion  323  is longer than the second sliding groove  117 , an end portion of the second positioning portion  323  projects into the third sliding groove  214 , which will prevent the downward movement of the lower connector  2  and combine the upper connector  1  and the lower connector  2  together. In addition, robust space is defined between the third sliding grooves  214  and the second positioning portion  323 , which will allow the lower connector  2  to move in a predetermined range with regard to the upper connector  1 . The vertical plate  325 / 326  acts as an ejecting portion when pushing the memory module out of the mating cavity  112 / 212  by pulling the operating portion  31 . 
     Referring to  FIGS. 1 and 6 , aligning posts defined on the upper and lower connectors  1 ,  2  are firstly inserted into the positioning hole  201  on the printed circuit board  200 , then the solder tails  121 ,  221  of the first and second terminals  12 ,  22  are inserted into the corresponding holes  202  on the printed circuit board  200  with the help of the aligning posts. As the lower connector  2  can move within a predetermined range, the solder tails  221  have a little room to be inserted into the corresponding holes  202  correctly and easily. Finally, a pair of nuts are provided to fasten the card edge connector assembly  100  onto corresponding screws  203  on the printed circuit board  200 . 
     In the present invention, the solder tails  121  of the first terminals  12  have an independent positioning plane from the solder tails  221  of the second terminals  22 , therefore the two groups of solder tails  121 ,  221  can separately be inserted into the corresponding holes  202 , which will reduce the difficulty of the soldering process. 
     It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.