Patent Publication Number: US-6341988-B1

Title: Straddle high density electrical connector

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to an electrical connector, and particularly to a straddle high density electrical connector which can be stably and accurately fixed onto a printed circuit board. 
     U.S. Pat. Nos. 5,603,639 and 5,893,764 disclose two different designs of electrical connectors which can be placed onto a printed circuit board with high precision. The U.S. Pat. No. 5,603,639 discloses an electrical connector which includes a connector body. A clamp piece receiving section is formed on each end of the connector body for engaging with a printed circuit board. However, special tools are required to properly position this electrical connector on the printed circuit board. The U.S. Pat. No. 5,603,639 was also designed to solve the location problem. The electrical connector of the U.S. Pat. No. 5,603,639 includes an elongated housing with a U-shaped mounting clip, and the U-shaped mounting clip further comprises a pair of legs joined by a bight portion. The legs are juxtaposed against two surfaces of a printed circuit board for connection to appropriate mounting pads. The electrical connector is adapted for straddle mounting to the printed circuit board at an edge thereof. However, the connection of the electrical connector and the printed circuit board before soldering only relies on the clamping of the legs to the pads. Such connection is not secure. If an outside force exceeding the clamping force is exerted against the connector, the connector can be moved from its desired position relative to the printed circuit board. Hence, an improved electrical connector is required to overcome the disadvantages of the prior art. 
     BRIEF SUMMARY OF THE INVENTION 
     A first object of the present invention is to provide an electrical connector which can be stably mounted to a printed circuit board; 
     A second object of the present invention is to provide an electrical connector which facilitates assembly to a printed circuit board. 
     Accordingly, a straddle high density electrical connector of the present invention comprises an insulative housing forming a projecting portion, a shield covering the projecting portion of the insulative housing, a pair of hooks, a plurality of terminals receiving in the insulative housing, and a pair of rivets for fastening the insulative housing, the shield and the hooks together. The insulative housing further comprises a pair of clamps positioned adjacent both ends thereof and extending rearwardly for clipping a printed circuit board therebetween. Each hook is positioned adjacent the corresponding clamp and has a pair of legs extending rearwardly from the housing, each leg has a tip at a free end thereof for inserting into a corresponding through hole defined in the printed circuit board which the electrical connector is mounted onto. In addition, each clamp comprises an upper receiving surface for engaging with the upper surface of the printed circuit board and a lower receiving surface for engaging with the lower surface of the printed circuit board, a triangular-shaped rib being formed on the lower receiving surface. Each tip of each hook projects beyond the corresponding upper receiving surface or lower receiving surface of a corresponding clamp, respectively. 
     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 an electrical connector in accordance with the present invention and a printed circuit board for connection with the electrical connector; 
     FIG. 2 is a view similar to FIG. 1 but from an opposite aspect, and a shield of the connector being separate from the connector; 
     FIG. 3 is a partially enlarged view of FIG. 1; 
     FIG. 4 is a side view of the electrical connector in accordance with the present invention; 
     FIG. 5 is a top view, partly in cross section, of the electrical connector in accordance with the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to FIGS. 1-3, an electrical connector in accordance with the present invention to be fixed onto a printed circuit board  6 , comprises an insulative housing  1  having a forward projecting portion  12  for mating with a complementary connector (not shown), a conductive shield  2  covering the projecting portion  12 , a plurality of terminals  3  received in the insulative housing  1 , a pair of hooks  4  and a pair of rivets  5 . The shield  2  comprises an opening  22  for receiving the projecting portion  12  and a plurality of retaining plates  24  extending rearwardly from upper and lower sides of the opening  22 . Each retaining plate  24  defines an aperture  240  therein. 
     The insulative housing  1  further has a plurality of recesses  18  positioned on upper and lower sides thereof and to a rear side of the projection  12 . The projecting portion  12  further defines a plurality of passageways  122  for receiving the terminals  3  to transfer signals therethrough. Each recess  18  defines a clipping block  182  to engage with the aperture  240  of the shield  2 . A pair of holes  19  is positioned on lateral ends of the insulative housing  1  to receive a pair of rivets  5  (see FIG.1) therein for fastening the shield  2 , the insulative housing  1  and a pair of hooks  4  together. A pair of clamps  14  is positioned near and between the two rivets  5 , each extending rearwardly opposite to the projecting portion  12 . A pair of metallic hooks  4 , is each fixed in a recess l 49  of the housing  1  positioned between a corresponding clamp  14  and rivet  5 , is to retain the electrical connector on the printed circuit board  6 . 
     Referring to FIGS. 1,  3  and  4 , each clamp  14  comprises an upper receiving surface  140  and a lower receiving surface  142  for engaging upper and lower surfaces (not labelled) of the printed circuit board  6  when the connector and the printed circuit board  6  are assembled together. A triangular-shaped rib  144  is formed on each lower receiving surface  142  to ensure that the printed circuit board  6  can be firmly clamped by the clamps  14  when the connector is mounted to the printed circuit board  6 . Each hook  4  consists of a pair of legs  42  projecting rearwardly from the housing  1  and toward each other at free ends thereof. The free ends each forms a tip  422  pointing toward each other. One tip  422  is positioned adjacent the upper receiving surface  140 , while the other tip  422  is positioned adjacent the lower receiving surface  142 , and the two tips  422  project beyond said upper and lower receiving surfaces  140 ,  142 . In addition, each clamp  14  defines a recess  149  for receiving a corresponding hook  4 . 
     Referring to FIG. 5, a first baffle  146  and a second baffle  148  are respectively formed on the clamps  14 . The two baffles  146 ,  148  have different lengths, the first baffle  146  being longer than the second baffle  148 . Referring to FIGS. 1-2, the printed circuit board  6  comprises a plurality of golden finger  68  on the upper and lower surfaces (only the upper surface show) thereof, a pair of through holes  66 , a first notch  62  and a second notch  64 . The two notches  62 ,  64  have different depths to cooperate with the two baffles  146 ,  148  of the clamps  14  respectively, and the through holes  66  are sized to receive the tips  422  of the hooks  4  to retain the electrical connector on the printed circuit board  6 . 
     In assembling, the connector is straddle mounted to an edge of the printed circuit board  6  by fitting the clamp  14  with the shorter baffle  148  into the second notch  64  and the clamp l 4  with the longer baffle  146  into the first notch  62  until a position is reached wherein the tips  422  of the hooks  4  fit within the corresponding through holes  66 . At this position, the upper receiving surfaces  140  of the clamps  14  and the lower receiving surface  142  of the clamps  14  with the ribs  144  clamp the printed circuit board therebetween, the rearward edges of the ribs  144  abutting a forward edge of the printed circuit board, and tail portions of the terminals  3  engage with the golden fingers  68  to transfer signals/power. 
     During assembly, the different depth of the notches  62 ,  64  perform a polarizing function together with the baffles  146 ,  148  to prevent incorrect assembly of the connector with the printed circuit board  6 ; the clamps  14  further perform a guidance function to guide the connector to a secure mounting with the printed circuit board  6 ; and the tips  422  of the hooks  4  which fit into the through holes  66  of the printed circuit board  6  provide a retaining function to secure the connector to the printed circuit board  6 . 
     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.