Abstract:
A socket connector ( 1 ) includes a base ( 10 ), a cover ( 20 ), two operating members ( 60 ), a lid ( 30 ), and four coil springs ( 40 ) received between the lid and the base. The base defines passageways ( 1010 ) receiving terminals therein. Each operating member includes a first operating lever ( 601 ) engaged with the cover, and a second operating lever ( 602 ) engaged with the base. The lid is engaged with the operating members for pivotably moving the first and second operating levers thereby the operating members actuating the cover to move in a horizontal direction. When no external force is exerted on the lid, the terminals in the base permit zero insertion force insertion and removal of the leads of the CPU, and when the lid is vertically pushed down, the operating members actuate the cover to move relative to the base thereby connecting the terminals with leads of the CPU.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an electrical connector such as one used for testing of integrated circuit (IC) packages, and particularly to an electrical connector with a cover and a pair of operating members. 
     2. Description of Prior Art 
     Test connectors are widely used for receiving and testing of IC packages. A conventional test connector includes a main body, a movable plate mounted on the main body, and a plurality of operating levers for actuating lateral movement of the movable plate along the main body. The movable plate is movable between a released state in which the IC package is attached thereon but electrically disengaged from terminals in the main body, and a contacting state in which the IC package is electrically engaged with the terminals of the main body. U.S. Pat. Nos. 5,186,642 and 5,690,281 disclose this kind of test connector. 
     FIG. 6 shows a conventional test connector  9 . The connector  9  comprises a base  91 , a cover  92 , a pair of operating members  95 , a pair of coil springs  94 , a pair of insert plates  96 , and a lid  93 . Each operating member  95  comprises a pair of operating levers  950  each defining a receiving hole  951  and a guiding groove  952 , a pair of supporting shafts  954  received in the receiving holes  951 , and a pair of transmission shafts  955  received in the guiding grooves  952 . The base  91  comprises a main body (not labeled) defining, a plurality of passageways  910  receiving a plurality of terminals (not shown) therein. The base  91  defines a pair of blind holes  914  for receiving the coil springs  94 . Each of opposite ends of the main body defines a pair of retaining grooves  912 , for receiving the supporting shafts  954  of the operating members  95 . The cover  92  defines a plurality of passages  920  in a main portion thereof, corresponding to the passageways  910  of the base  91 . The cover  92  comprises four projections  922  protruding upwardly from fours corner thereof. A pair of elongated receiving grooves  924  is defined in opposite ends of the cover  92  respectively, at the projections  92 . The receiving grooves  924  are for receiving the transmission shafts  955  of the operating members  95 . The lid  93  is substantially a rectangular frame, and defines a central opening  930 . A pair of receiving recesses (not shown) is defined in bottoms of opposite sidewalls  932  of the lid  93  respectively, for receiving the corresponding insert plates  96  therein. 
     Referring also to FIG. 7, in assembly, the cover  92  is movably mounted on the base  91 . The supporting shafts  954  of the operating members  95  are pivotably received in the retaining grooves  912  of the base  91 , and the transmission shafts  955  of the operating members  95  are pivotably received in the receiving grooves  924  of the cover  92 . The insert plates  96  are mounted on the operating members  95 , and are then fixed in the recesses of the lid  93 . The coil springs  94  are mounted between the base  91  and the lid  93 . The lid  96  is thereby engaged with the operating members  95  and movably mounted on the base  91 . 
     In use, the lid  93  is pushed downwardly by a robot or an operator&#39;s hand (not shown), with corresponding force being applied to the operating members  95 . The operating members  95  drive the cover  92  to move horizontally in a direction toward one of the ends of the base  91 . When the lid  93  has reached a bottommost position, the coil springs  94  are compressed, and the cover  92  is defined to be in an open state. In the open state, an IC package (not shown) can be attached on the cover  92 , with leads of the IC package passing through the passages  920  of the cover  92  and being received in the passageways  910  of the base  91  with zero insertion force (ZIF). That is, when the IC package is attached on the cover  92  in the open state, the leads of the IC package are not in mechanical or electrical engagement with the terminals of the base  91 . When said downward pushing by the robot or the operator&#39;s hand is released, the coil springs  94  decompress, and the cover  92  is driven horizontally in an opposite direction toward its original position. The leads of the IC package thereby mechanically and electrically engage with the terminals of the base  91 . In this position, the cover  92  is defined to be in a closed state. 
     In the conventional connector  9 , if a force of said downward pushing on the lid  93  is insufficient, the cover  92  is driven only part of the way toward the open state. When the IC package is then attached on the cover  92 , the leads of the IC package are received in the passageways  910  and interfere with the terminals of the base  91 . The leads and the terminals are thus liable to sustain damage. In addition, even when said downward force is sufficient, the shafts  955  are driven to respective endmost portions of the guiding grooves  952 , whereat respective walls of the operating levers  952  apply forces on the shafts  955 . Smooth movement of the shafts  955  is retarded and interrupted by such forces. Thus, smooth movement of the cover along the base  91  is disrupted, which can result in damage to the leads of the IC package and the terminals of the base  91 . Furthermore, in the open state, if said downward force is released suddenly, the coil springs  94  rapidly decompress and drive the lid  93  upwardly, and the cover  92  is quickly driven to the closed state. When this happens, the leads of the IC package enter the terminals of the base  91  with great speed and force, and the leads and the terminals are liable to sustain damage. 
     A new connector that overcomes the above-mentioned problems is desired. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to provide a connector which prevents or minimizes the risk of damage to leads of an IC package received in the connector. 
     In order to achieve the above object, a socket connector in accordance with a preferred embodiment of the present invention comprises a base, a cover movably mounted on the base, a pair of operating members, a lid, four coil springs received between the lid and the base, and a pair of insert plates. The base defines a plurality of passageways receiving a plurality of conductive terminals therein. Each operating member comprises a first operating lever engaged with the cover, and a second operating lever engaged with the base. The first and second operating levers are pivotably attached to their respective insert plates, and the insert plates are mounted to the lid respectively. The lid is thereby disposed above the operating members for pivotably moving the first and second operating levers. When no external force is exerted on the connector, the terminals in the base permit zero insertion force insertion and removal of the leads of the IC package, and when the lid is vertically pushed down by an external force, the operating members actuate the cover to move relative to the base thereby connecting the terminals with leads of the CPU. 
     Other objects, advantages and novel features of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which: 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a simplified, exploded isometric view of a socket connector in accordance with the preferred embodiment of the present invention; 
     FIG. 2 is an assembled view of FIG. 1, but not showing a lid of the socket connector; 
     FIG. 3 is a complete assembled view of FIG. 1; 
     FIG. 4 is a side elevation view of FIG. 3, showing a cover and a pair of operating members of the socket connector in respective first positions; 
     FIG. 5 is similar to FIG. 4, but showing the cover and the operating members in respective second positions; 
     FIG. 6 is a simplified, exploded isometric view of a conventional connector; and 
     FIG. 7 is an assembled view of FIG.  6 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Reference will now be made to the drawings to describe the invention in detail. 
     Referring to FIG. 1, a socket connector  1  in accordance with the preferred embodiment of the present invention is adapted for receiving an integrated circuit (IC) package such as a central processing unit (CPU) (not shown) in order to test the CPU. The socket connector  1  comprises a generally rectangular base  10  fixed on a circuit substrate such as a printed circuit board (PCB) (not shown), a generally rectangular cover  20  slidably mounted on the base  10 , a lid  30 , four coil springs  40 , a pair of insert plates  50 , and a pair of operating members  60  for actuating horizontal movement of the cover  20 . 
     The cover  20  comprises a main body  201  for receiving the CPU thereon A plurality of passages  2010  is defined in the main body  201  in a rectangular array, for extension therethrough of a plurality of leads of the CPU. A pair of spaced, aligned projections  204  is formed on one end of the cover  20 . A pair of first receiving grooves  206  is defined in bottoms of the projections  204  respectively. The main body  201  defines four sidewalls not labeled). Each of two opposite lateral sidewalls forms a pair of spaced, aligned latch portions  202 . Each latch portion  202  has a hook portion  2020  at a bottom end thereof. 
     The base  10  comprises a rectangular main portion  101 , a pair of first side portions  102  at opposite lateral sides of the main portion.  101  respectively, and a pair of second side portions  103  also at opposite lateral sides of the main portion  101  respectively. The first side portions  102  are spaced from the corresponding second side portions  103 . The main portion  101  defines a plurality of passageways  1010  corresponding to the passages  2010  of the cover  20 , and four blind holes  1012  in four corners thereof for receiving the coil springs  40  respectively. A plurality of conductive terminals (not shown) is received in the corresponding passageways  1010 . A pair of spaced, aligned retaining slots  1014  is defined in each of the opposite lateral sides of the main body  101 , for receiving corresponding latch portions  202  of the cover  20 . A pair of first latches  104  is formed on the first side portions  102  respectively, and another pair of first latches  104  is formed on the second side portions  103  respectively. Each first latch  104  has a first hook protrusion  1040  protruding outwardly from a top end thereof. A pair of tapered tenons  106  extends upwardly from the first side portions  102  respectively. A pair of diagonally opposite columns  108  protrudes from one first side portion  102  and one second side portion  103  respectively, for fixing the base  10  on the PCB. A pair of second receiving grooves  1020  is defined in the second end portions  103  respectively, one of the second receiving grooves  1020  being adjacent one of the columns  108 . 
     The lid  30  is substantially a rectangular frame, and defines a central opening  301  corresponding to the main body  201  of the cover  20 . The CPU is inserted and removed through the opening  301 . Four blind holes (not shown) are defined in four corners of a bottom of the lid  30  respectively, corresponding to the blind holes  1012  of the base  10 . Each of opposite lateral sidewalls (not labeled) of the lid  30  defines a pair of spaced first mounting holes  304 , for fastening a corresponding insert plate  50  thereunder. A pair of tapered cutouts  306  is defined in the lateral sidewalls respectively, corresponding to the tenons  106  of the base  10 . A pair of second latches  302  depends from each opposite lateral sidewall, the second latches  302  corresponding to the first latches  104  of the base  10 . Each second latch  302  has a second hook  3020  at a distal end thereof, the second hooks  3020  corresponding to the first hooks  1040  of the first latches  104 . Each second latch  302  defines an inner guiding groove  3022 , the guiding grooves  3022  receiving the first latches  104  therein. 
     Each insert plate  50  comprises a horizontal top plate  501 , and a vertical middle plate  502  depending from a middle of the top plate  501 . A pair of second mounting holes  503  is defined in opposite ends of the top plate  501  respectively. A pivot hole  505  is defined in the middle plate  502 , for hinging engagement of a corresponding operating member  60  thereat. 
     Each operating member  60  comprises a first operating lever  601 , a second operating lever  602 , a first shaft  603  engaged with the first operating lever  601 , and a second shaft  604  engaged with the second operating lever  602 . The first operating lever  601  defines a first through hole  6010  in an end thereof, corresponding to the pivot hole  505  of a respective insert plate  50 . The second operating lever  602  defines a second through hole  6020  in an end thereof, also corresponding to the pivot hole  505  of the respective insert plate  50 . A pivot pin  70  is used for pivotably attaching the operating member  60  to the respective insert plate  50 . 
     Referring to FIGS. 2 and 3, in assembly, the cover  20  is placed on the base  10 . The second shafts  604  of the operating members  60  are pivotably received in the second receiving grooves  1020  of the base  10 , and the first shafts  603  of the operating members  60  are pivotably received in the first receiving grooves  206  of the cover  20 . The first and second operating levers  601 ,  602  are pivotably attached to their respective insert plates  50  by respective pivot pins  70 . The insert plates  50  are mounted to undersides of the lateral sidewalls of the lid  30  respectively. The coil springs  40  are mounted between the lid  30  and the base  10 . The lid  30  is thereby disposed above the operating members  60 , and movably engaged on the base  10 . The lid  30  is vertically movable relative to the base  10 . 
     Referring to FIG. 4, the socket connector  1  is in a relaxed state, with the cover  20  and the operating members  60  defined to be in respective first positions. In use, the CPU is inserted through the opening  301  of the lid  30  and engaged on the cover  20 . The leads of the CPU are received through the passages  2010  of the cover  20 , and then in the passageways  1010  of the base  10  with zero insertion force (ZIF). That is, the leads of the CPU do not contact the terminals (not shown) of the base  10 . 
     Referring to FIG. 5, when the lid  30  is pushed downwardly by an external force, corresponding force is applied to the first and second operating levers  601 ,  602 . The first and second operating levers  601 ,  602  are pivoted downwardly about the first and second shafts  603 ,  604  at the pivot pins  70 . The first and second operating levers  601 ,  602  cooperatively translate such pivotal movement into horizontal force acting on the first shafts  603 . Thus, the first shafts  603  drive the cover  20  to slide horizontally from the first position to a second position in which the leads of the CPU engage with the terminals of the base  10 . When the cover slides from the first position to the second position, the coil springs  40  are compressed. In addition, the tenons  106  of the base  10  are received in the cutouts  306  of the lid  30 , thereby preventing lateral movement of the lid  30  relative to the base  10 . When said downward force is released, the coil springs  40  decompress and drive the lid  30  upwardly. The first shafts  603  accordingly drive the cover  20  to slide back from the second position to the first position. 
     The socket connector  1 , unlike conventional socket connectors, provides for insertion of the leads of the CPU into the passageways  1010  of the base  10  when the socket connector  1  is in a relaxed state. That is, when the cover  20  is in the first position. This ensures that the leads of the CPU are received in the passageways  1010  of the base  10  with ZIF. Similarly, after testing of the CPU, the socket connector  1  is returned to the first position by decompression of the coil springs  40 . This ensures that the leads of the CPU can be removed from the passageways  1010  with zero removal force. Thus, the leads of the CPU are protected from damage during both engagement and disengagement of the CPU on and from the socket connector  1 . In addition, if said downward force is insufficient, the cover  20  is driven only part of the way toward the closed state. Because the IC package is already attached on the cover  20 , the leads of the IC package do not sustain damage when they are only partly engaged with the terminals of the base  10 . Furthermore, in the closed state, if said downward force is released suddenly, the coil springs  40  rapidly decompress and drive the lid  30  upwardly, and the cover  20  is quickly driven to the open state. When this happens, the leads of the IC package exit the terminals of the base  10 . Rapid exiting of the leads from the terminals is less likely to cause damage thereto compared with rapid entering of the leads into the terminals as in conventional art. Moreover, the second shafts  603  are pivotably engaged with the base  10 , while the first shafts  604  are pivotably engaged with the cover  20 . Thus, the above-described sliding of the cover  20  relative to the base  10  can be performed smoothly and easily without retardation or interruption. 
     While a preferred embodiment in accordance with the present invention has been shown and described, equivalent modifications and changes known to persons skilled in the art according to the spirit of the present invention are considered within the scope of the present invention as defined in the appended claims.