Abstract:
Retention systems for use with processor modules ( 20 ) on circuit boards upon mating with connectors ( 12 ). Such systems utilize end blocks ( 44 ) at ends ( 36 ) of the connector, having retention members ( 54 ) for securing the processor module in its mated position with the connector, stabilizing the module and relieving stress from the connector. Resilient members ( 80 ) are compressed by a leading end ( 26 ) of the module at sides ( 32 ) thereof upon full insertion into the retention members ( 54 ), maintaining sufficient pressure on the latching system ( 34,60 ) to remove looseness from the assembly and stabilize the module against the effects of vibration and other movement.

Description:
This application claims benefit to provisional application 60/073,017 filed Jan. 29, 1998. 
    
    
     FIELD OF THE INVENTION 
     This relates to the field of electrical connectors and more particularly to components mountable to a circuit board. 
     BACKGROUND OF THE INVENTION 
     In computers and other electronic equipment, circuit boards are utilized to which are mounted numerous electrical and electronic components. Smaller circuit cards are utilized to establish electrical connections to a larger circuit board in a manner that permits removal and disconnection, by inserting an edge of the card into a receptacle connector mounted on the board and containing an array of contacts connected to circuits of the board; contact sections of the contacts are exposed within a card-receiving cavity of the connector that engage circuit pads on the card surfaces upon card insertion. It has become useful to secure certain cards within larger modules so that components mounted on the card are protected by the module covers during handling. Such modules, such as Slot  1  processor modules, need to be accurately guided during mating with the receptacle connector so that the leading end of the enclosed card is accurately received into the card-receiving cavity of the connector, since the module covers inhibit accurate visual alignment of the card with the cavity. It is known to provide elongate retention members projecting from the board from ends of receptacle connectors to facilitate mating in similar situations. 
     It is desired to assure that all tolerance is eliminated between the processor module and the retention members, to eliminate looseness from the resulting mated assembly and stabilize the module against the effects of vibration and other movement. 
     SUMMARY OF THE INVENTION 
     The present invention provides resilient members adjacent the inner ends of the retention members and at opposed ends of the receptacle connector that are positioned between the retention members, to be engaged and compressed by ends of the leading end of the processor module upon full mating with the connector, as the module is latched in the fully mated position by the retention members so that the compressed resilient members continue thereafter to exert pressure to maintain the fully latched engagement of the cooperating latch members. 
     In embodiments where the housing of the receptacle connector includes integral mounting blocks at ends thereof, where elongate retention members are either integral with or are affixed to the mounting blocks, resilient members are retained in openings of the mounting blocks to be compressed by opposed ends of the leading end of the module cover upon full mating with the connector and latching with the retention members. 
     In other embodiments where the mounting blocks that are separate members affixed at ends of the receptacle connector housing and the retention members are integral with the mounting blocks, recesses are provided in the mounting blocks into which are inserted resilient members that are disposed at the connector ends to be engaged by the module cover leading end; the mounting blocks may be mountable either to the circuit board or may be locked to the connector housing. 
    
    
     Embodiments of the present invention will now be described by way of example with reference to the accompanying drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an isometric view of a connector mounted on a circuit board, with an integral retention module therearound mounted to the board, and a processor module positioned to be inserted into the retention module for mating with the connector; 
     FIG. 2 is an isometric view of the retention module and the connector of FIG. 1, with one of the resilient members exploded therefrom with another placed in position; 
     FIG. 3 is an enlarged isometric view of one end of the assembly of FIG. 1; 
     FIG. 4 is an enlarged longitudinal sectional view of one end of the assembly of FIG. 1 with a processor module mated with the connector; 
     FIG. 5 is an isometric view of a second embodiment of retention system where end blocks are integral with the connector, with discrete pivotable retention members, boardlocks and resilient members exploded therefrom; 
     FIG. 6 is an isometric view of a resilient member of FIG. 5; 
     FIGS. 7 and 8 are enlarged isometric views of one end of the connector of FIG. 5 before and after assembling the resilient member of FIG. 6 into position; 
     FIG. 9 is an isometric view of the assembly of FIG. 5 with the retention members pivoted into a recumbent orientation prior to mating with a processor module; 
     FIG. 10 is an exploded isometric view of a third embodiment of retention system having separate board-mountable end blocks exploded from ends of a connector, with retention members, boardlocks and resilient members exploded therefrom; 
     FIG. 11 is an enlarged part view of one end of the retention system of FIG. 10 after assembly; 
     FIG. 12 is an enlarged view of one of the retention assemblies of FIG. 10; 
     FIG. 13 is an enlarged isometric view of a resilient member of FIGS. 10 to  12 ; 
     FIG. 14 is an isometric view of a fourth embodiment of retention system, with separate end blocks affixed to the ends of a connector; 
     FIG. 15 is an isometric view of one of the end block assemblies of FIG. 14; and 
     FIGS. 16 and 17 are top and bottom isometric views of the end block of FIG. 15 with a resilient member exploded therefrom. 
    
    
     DETAILED DESCRIPTION 
     Assembly  10  of FIGS. 1 to  4  illustrates a first embodiment of retention system utilizing the resilient members of the present invention. A receptacle connector  12  is shown mounted on a circuit board  18  and having a housing  14  of insulative material having a card-receiving cavity or slot  16  along both sides of which are arrays of contacts (not shown). Connector  12  may be, for example, of the type sold by AMP Incorporated under Part Nos. 145251-1 and -2. A processor module  20  is shown positioned above Connector  12  to become mated therewith; module  20  includes a circuit card  22  affixed within a protective covering  24 , and a leading end  26  of the module is open to expose the leading end  28  of the card to be inserted into card-receiving slot  16  of connector  12  upon mating. Contacts of connector  12  are engageable with circuit pads of the card adjacent the leading end thereof. The processor module may have a massive heat sink (not shown) mounted along one side thereof. 
     The retention system includes a one-piece frame  40  which defines a connector-receiving opening  42  therealong including end blocks  44  that are integral therewith at opposed ends  46  of opening  42 . Fasteners  64  are held in holes  50  through flanges  52  to either side of each end block  44  used in cooperation with bolts (not shown) for securing frame  40  firmly to circuit board  18 , as disclosed in greater particularity in U.S. patent application Ser. No. 09/063,127 filed Apr. 20, 1998 and assigned to the assignee hereof. 
     A retention member  54  is integral with each end block  44 , extending upwardly from ends  46 . Each retention member  54  is U-shaped to define a guide channel  56  along the inner surface thereof and precisely aligned with card-receiving slot  16  of connector  12 . Guide channels  56  are dimensioned to receive therein side portions  32  of module  20  so that card leading end  28  becomes aligned for receipt into card-receiving cavity  16  during mating for the circuit pads thereof to become electrically engaged by the connector&#39;s contacts. Entrances to the guide channels may be chamfered to facilitate insertion of the module side portions  32  thereinto. Retention members  54  are positioned spaced apart so that channel bottom surfaces  58  oppose each other spaced apart a width of the module in order to position the module accurately lengthwise of the card-receiving slot. The retention members  54  include latch apertures  60  as shown within which corresponding latch projections  34  on side surfaces of the module may latch, for retention in the mated condition. Sufficient clearances  62  around ends  36  of connector  12  are provided by retention members  54  for receipt thereinto of leading end  26  of the module covering  24  around connector ends  36 , when card leading end  28  is received into card-receiving slot  16 . 
     Resilient members  80  of the present invention are seated in clearance openings  62  at inner ends of channels  56  outwardly of ends  36  of connector  12  and positioned atop upwardly facing surfaces  48 , such as by being in interference fit between opposed walls of retention member  54 , or optionally by being bonded in place. Resilient members  80  are shown to include a transverse body section  82  adjacent channel bottom  58 , and side flanges  84  extending orthogonally therefrom that coextend partially along side surfaces of connector  12 . Resilient members  80  are thus configured similarly to the ends  32  of cover  24  of module  20  and thus are abutted and compressed thereby against surfaces  48  when module  20  is fully moved along channels  56  to mate with connector  12 , for leading end  28  of card  22  to be received into card-receiving slot  16 , at which time latch projections  34  are latched in latch recesses  60  of retention members  54 . 
     As shown in FIG. 4, resilient members  80  upon compression by module  20 , exert a force upwardly on the module to maintain the latch projections  34  firmly in latching engagement with latching surfaces of recesses  60 . This results in no looseness or tolerances that would otherwise permit the module to move incrementally during movement of a computer or vibration thereof, and this in turn enhances the stability of the electrical connections as well as reduces wear and tear on the components within the module during in-service use. Additionally, resilient members  80  exert a force upwardly on a module to partially eject the module during delatching of the module latches, facilitating module removal when service personnel are manually actuating the latch members on opposed sides of the module, urging them toward each other. Resilient members  80  may be of elastomeric material such as foam rubber or rubber such as from Buna-N nitrile resin, ASTM-NBR. 
     Referring now to FIGS. 5 to  9 , a second embodiment of retention system is shown. The retention system is comprised of a pair of end block assemblies  100  at ends  102  of connector  104 . End block assemblies  100  include end blocks  106  integral with housing  108  of connector  104 , and boardlocks  110  are inserted into slots  112  through flanges  114  so that retention legs  116  of the boardlocks are received into mounting holes (not shown) of the board, for mounting the connector to the circuit board in accordance with a conventional connector-mounting technique, wherein access to the bottom of the circuit board is unnecessary. An additional board lock is also seen approximately in the middle of elongate connector  104 . 
     End block assemblies  100  also include retention members  118  that are pivotably mounted to end blocks  106 ; the retention members are pivotable between upright positions orthogonal to the board and the receptacle connector  12  to receive a processor module therealong, and recumbent positions (see FIG.  9 ); pivot pins  120  are seated in holes  122  through bottom tabs  124  of side walls  126  of retention members  118 , with tabs  124  temporarily deflected toward each other until pins  120  become seated in holes  122 . The recumbent positions are useful during shipping and handling at which time no module would be utilized, minimizing a potential to be damaged and also minimizing the overall height of the retention system to facilitate handling and storage, all as is discussed in U.S. Ser. No. 09/063,127 filed Apr. 20, 1998. 
     Clearances  130  are defined adjacent to connector ends  102 , with openings  132  (FIG. 7) in communication with board-mounting face  134  of the connector housing. Resilient members  140  are insertable into openings  132  from board-mounting face  134  and self-secure therein. Each resilient member  140  includes a transverse body  142  and opposed side walls  144  extending orthogonally therefrom. Along an outer surface of each side wall  144  is seen a flange  146  extending outwardly, and a retention rib  148  projecting further outwardly therefrom. Retention ribs  148  will define an interference fit with end block  106  when the resilient member  140  is inserted into opening  132  from board-mounting face  134 , with flanges  146  abutting ledges adjacent to the sides of opening  132  when the resilient member is fully inserted, upon which upper portions of transverse body  142  and side walls  144  will project upwardly into clearance  130 , as seen in FIG.  8 . Resilient members  140  will be compressed directly against the circuit board upon full module insertion. 
     In FIGS. 10 to  13  is shown a third embodiment of retention system, wherein retention assemblies  200  are separate from connector  202 , with the connector and the retention assemblies to be separately mounted to a circuit board. End block members  204  each are board mounted by boardlocks  206 . Retention members  208  are pivotably mountable to end block members  204 , similarly to retention members  118  of FIGS. 5 to  9 . 
     Resilient members  210  are again insertable into openings  212  of end blocks  204 , and vertical retention ribs  214  are defined along vertical flanges  216  projecting outwardly from side walls  218  of the resilient members to define an interference fit within vertical channels  220 . Channels  220  extend upwardly from board-mounting face  222  of end block members  204  to communicate with openings  212  and clearances  224 , with upper portions of transverse body  226  and side walls  218  rising above upwardly facing surfaces  228  of the end block adjacent the connector-receiving recess  230  and projecting into clearances  224 , as is seen in FIGS. 11 and 12. In FIG. 12, the connector is not illustrated, in order to reveal the resilient member in position within the end block. As with resilient members  140  of FIGS. 4 to  9 , resilient members  210  will be compressed directly against the circuit board upon full module insertion. 
     A fourth embodiment of retention system is shown in FIGS. 14 to  17 . Retention assemblies  300  are securable to ends  302  of the connector  304  instead of to the circuit board. Retention assemblies  300  each include an end block member  306  having a retention member  308  integral therewith. Each end block member  306  is adapted to be affixable to the connector after the connector has been mounted onto the circuit board, by a pair of latch projections  310  along inwardly facing surfaces of the connector-receiving recess  312  defined between flanges  314 , to latch beneath complementary latch projections  316  along outwardly facing surfaces of housing  318  of connector  304  proximate a respective end  302  when end block member  306  is urged downwardly at end  302 . 
     Resilient member  320  is insertable into opening  322  in end block member  306  from board-proximate face  324 , and is preferably dimensioned to be slightly larger cross-sectionally than the opening to define an interference fit therein for retention prior to being affixed to the previously board-mounted connector. An outwardly extending flange  326  extends into a corresponding shallow recess  328  along board-proximate face  324  to assure that the resilient member will not be overinserted into opening  322 ; preferably the thickness of flange  326  is sufficient to protrude slightly below board-proximate face  324  and will engage the circuit board after retention assembly  300  is affixed to the connector when compressed by a processor module upon module mating with connector  304 . Also seen in FIG. 17 are a pair of locating bosses  330  depending from board-proximate face  324  to be received into corresponding holes of the circuit board and stabilizing the retention member against lateral movement along the circuit board, such as when a processor module is inserted along guide channels  332  of retention members  308  and isolating connector  304  from stresses resulting therefrom. 
     The present invention provides an efficient manner of removing looseness of a module in the retention assembly, and additionally facilitates removal of a module from its mated condition with the receptacle connector by partially ejecting the module upon delatching. 
     Modifications and variations may occur from the specific examples provided herein, that are within the spirit of the invention and the scope of the claims. The resilient member may be used with a connector having integral module retention systems, or with add-on retention systems. The present invention may for example be utilized with board-mounting arrangements other than that used for processor modules.