Patent Publication Number: US-6655997-B2

Title: Electrical connector with a releasable housing

Description:
FIELD OF THE INVENTION 
     The present invention relates to electrical connectors. More specifically, the present invention relates to the field of electrical connectors for printed circuit boards. 
     BACKGROUND OF THE INVENTION 
     It is well known in the art to provide an electrical connector which includes contacts having solder tails which may be soldered to the solder pads of a printed circuit board (PCB). The connectors of the prior art provide connectors housings having the electrical contacts securely retained therein so that once the connector is soldered to the PCB the connection is non-removably affixed to the PCB. 
     Should the PCB require rework, the typical approach for effecting recovery of the PCB requires cutting the contacts proximate to the solder tails to separate the remainder of the connector from the PCB, and then severing the solder connection between the PCB and the solder tail by applying heat or by other method known in the art. The PCB could then be cleaned and reworked so that a new connector could be mounted to the solder pads of the PCB. In these rework procedures, however, the removal of the connector tends to result in the twisting of the contacts while cutting the solder tails. Twisting of the contacts can translate through the solder pads of the PCB to cause scratching and delamination of the PCB, or lifting or detaching of the solder pads from the PCB. Such damage can render the PCB un-reusable. 
     There is therefore a need in the art for a connector design which provides a quick release between the contacts and the housing so as to minimize the damage to or delamination of the PCB pad during rework. This new design would obviate the need for cutting the contact while it remains soldered to the PCB by providing access to detach the contacts from the housing. This new design would thereby eliminate the chance of damage to or delamination of the masked surfaces of the PCB by the cutting process. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of the present invention to provide a connector the housing of which may be easily detached from the contacts contained therein. 
     It is another object of the present invention to provide a connector for a PCB which minimizes the chance of damage to the PCB or its solder pads during rework of the PCB. 
     It is still another object of the present invention to provide a connector for a PCB which obviates the need for cutting of the solder tails connecting the connector to the PCB. 
     It is yet another object of the present invention to provide a connector for a PCB which facilitates the recovery process. 
     These and other objects are obtained by the present invention by providing a connector having a releasable connector housing. The connector supports a number of elongate contacts in a number of elongate cavities defined by the connector housing. Each contact includes a solder tail at one end, a deflectable wiping connection element at the other end, and a contact body therebetween. The contact body includes a deflectable tang extending acutely therefrom in interfering engagement with a locking shoulder extending in the cavity. The housing also defines a tang access aperture in communication with each cavity so as to render each tang accessible therethrough. A separation tool having a prong for each tang may engage the housing through each access aperture to deflect the tangs away from the interfering engagement with the locking shoulders. With each tang simultaneously out of interfering engagement with the locking shoulders, the housing may be separated from the contacts while the contacts are still soldered to a printed circuit board. The solder tails may then be disconnected from the printed circuit board without the need for cutting the contacts. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a cut-away view of a connector of the present invention having an in-line access aperture. 
     FIG. 2 shows the connector of FIG. 1 after the contacts have been released from the housing. 
     FIG. 3 is a cut-away view from the underside of the connector of FIG. 1 soldered to a PCB. 
     FIG. 4 is a cut-away view of from the underside of the connector of FIG. 1 after the contacts have been released from the housing. 
     FIG. 5 depicts a tool for separating the contacts from the housing of the connector of FIG.  1 . 
     FIG. 6 depicts an alternate embodiment of the connector of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1 shows a connector  10  of the present invention. Connector  10  includes an elongate housing  12  having a plurality of spaced-apart elongate cavities  14  extending therealong. Housing  12  is preferably formed of a suitable insulative molded plastic that complies with the UL94-V0 standard such as polyphenylene sulfide, liquid crystal polymer, polyphthalamide, or nylon 46. 
     Within each cavity  14  housing  12  supports an electrical contact  16 . Each contact  16  includes solder tail  18  at one end, deflectable wiping engagement member  20  at the other end, and elongate contact body  22  therebetween. Contact body  22  supports deflecting tang  24  at an acute angle thereto. When contact  16  is inserted into housing  12 , tang  24  extends in interfering engagement with locking shoulder  26  formed in housing  12 . Wiping engagement member  20  terminates at tab  28 . Tab  28  extends transversely to contact  16  so as to abuttingly engage cavity shoulder  30 . 
     With additional reference to FIG. 3, solder tail  18  is connected to printed circuit board (PCB),  32 . Preferably, solder tail  18  is soldered to solder pad  32  as is well known in the art for connecting an electrical contact to a PCB. Whereas contact  16  is thereby soldered to PCB  32 , contact  16  is simultaneously retained in housing  12  by mechanical interference. 
     As shown in FIGS. 2 and 4, contact body  22  includes both depending tang  24  and contact shoulders  36 ,  37 . Contacts  16  are insertable into cavities  14  of housing  12  in an insertion direction A. Contact shoulders  36 ,  37  limit the extent to which contact  16  may be inserted into housing  12  by abutting against cavity shoulders  38 ,  39 . For purposes of clarity, cavity shoulder  39  is not shown but is positioned transversely across cavity  14  from cavity shoulder  38 . As contact  16  is inserted into cavity  14 , depending tang  24  deflects towards contact body  22  until it is positioned adjacent locking shoulder  26 , at which point tang  24  extends away from contact body  22  into interfering engagement with locking shoulder  26 . The interfering engagement between tang  22  and locking shoulder  26  prevents contact  16  from being withdrawn from housing  12  in a withdrawal direction B, opposite to insertion direction A. 
     With PCB  32  soldered to one end of contact  16 , and with contact  16  securely retained within housing  12 , connector  10  provides for mating electrical connection between wiping engagement elements  20  and the contacts of another electrical connection component, not shown, thereby enabling PCB  32  to function as designed. 
     The present invention is more specifically directed to a later phase in the life cycle of PCB  32 , where the need arises for PCB  32  to be separated from connector  10  and reworked for overhaul or maintenance purposes. As contact  16  is positively retained within housing  12  and soldered to PCB  32 , current rework procedures would call for detaching connector  10  from PCB  32  by cutting contact body  22  near solder tail  18 . Heat would then be applied to the solder connection between solder tail  18  and PCB  32  to disconnect solder tail  18 . Once PCB  32  had been reworked, a new connector  10  would then be attached to PCB  32  as before. As previously noted, the cutting stresses applied to contact  16  can translate into shearing forces and bending moments at solder pad  34  which can cause solder pad  34  to lift or detach from PCB  32  or scratch the masked surfaces of PCB  32 . 
     The present invention obviates the need for cutting the contacts  16  by providing for the quick and easy release of contacts  16  from housing  12  while still soldered to PCB  32 . Housing  12  provides an access aperture  40  which communicates with cavity  14  and renders tang  24  accessible. A separation tool  42 , shown in FIG. 5, having tang-engaging prongs  44  may engage housing  12  so that each prong  44  is inserted into each access aperture  40  to deflectingly engage each tang  24  towards contact body  22  and out of interfering engagement with the locking shoulders  26 . With each tang  24  now out of interfering engagement with its associated locking shoulder  26 , PCB  32  may be moved in the withdrawal direction B from engagement with housing  12  with each contact  16  still in soldered connection therewith, as shown in FIGS. 2 and 4. Each contact  16  may be disconnected from PCB  32  by the present method of separating solder tail  18  from solder pad  34 . The present invention thereby eliminates the risk of damage to PCB  32  resulting from cutting the solder tails  18  from connector  10 . 
     With further reference to FIG. 5, separation tool  42  is an actuatable assembly having a first member  46  which is pivotally attached to a second member  48  at a pivot location  50 . A spring  52  is interposed between first member  46  and second member  48  on one side of pivot location  50 . Spring  52  biases first member  46  and second member  48  to a closed position. Separation tool  42  further includes elongate grappling arms  54  at one end of first member  46 . Grappling arms  54  are in spaced opposition to a holding member  56  formed at one end of second member  48 . The free ends of grappling arms  54  include hookfaces  58  which engage the top-forward surfaces  60  of housing  12  (FIGS. 1 and 4) without blocking the passage of any wiping engagement member  20  as it is withdrawn though its cavity  14  when separation tool  42  is in the closed position. In the closed position, each tang-engaging prong  44  extends far enough into its associated access aperture  40  to deflect the associated tang  24  away from interfering engagement with its opposing locking shoulder  26  so that all of the contacts  16  may be simultaneously withdrawn from housing  12  with the PCB  32 . 
     Although access aperture  40  is shown to extend in-line with, or parallel to contact body  22 , it is also contemplated that the access aperture may be differently disposed with respect to contact body  22 . For example, FIG. 6 shows an alternate embodiment of the present invention whereby access aperture  62  is formed adjacent locking shoulder  26  so as to provide a more perpendicular engagement between the prongs of a separation tool (not shown) and each tang  24 . 
     While the particular embodiment of the present invention has been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the teachings of the invention. The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as a limitation. The actual scope of the invention is intended to be defined in the following claims when viewed in their proper perspective based on the prior art.