Abstract:
An electric connector assembly is provided having a housing with a chamber therein having an open end configured to receive a plug contact. The electric connector assembly includes a receptacle contact having a contact box on one end located in the chamber. The electrical connector has a contact pin on an opposite end extending from the chamber, and the contact box has a latch feature on a periphery thereof securing the contact box to the housing. The contact box has an open front end aligning with the open end of the chamber that is configured to receive a plug contact. The receptacle contact further includes a compliant section between the contact box and contact pin that is flexible to absorb vibrations introduced into the contact box and contact pin.

Description:
BACKGROUND OF THE INVENTION 
     Certain embodiments of the present invention generally relate to an electrical connector containing axially compliant contacts that electrically connect components such as printed circuit boards. 
     In certain applications, such as in an automobile, electronic components aligned perpendicularly to each other and separated by a firewall are connected to each other by mateable plug and receptacle housings, also known as a board-to-board connector assembly. The plug and receptacle housings include plug and receptacle contacts, respectively. Each receptacle contact is bent so that a front portion is perpendicular to a rear portion. The receptacle contacts are positioned in the receptacle housing so that the front portions mateably receive the plug contacts, which are connected to a first printed circuit board, and the rear portions are connected to a second printed circuit board that is oriented perpendicular or at an acute angle to the first printed circuit board. 
     In conventional board-to-board connector assemblies, the front portions of the receptacle contacts are press fit within cavities in the plastic receptacle housing while the rear portions extend exposed down through a base wall of the housing. Because the rear portions are not covered by the receptacle housing and are only retained at the base wall, the rear portions are easily affected by outside forces which may cause the rear portions to vibrate. As the vibrations travel along the receptacle contacts, the vibrations cause the front portions to become loose or distorted within the cavities in the receptacle housing. Thus, constant vibration wears and damages the receptacle housing and the front portions of the receptacle contacts as well as adversely affects the connection with the plug contacts. 
     Also, because the front portions of the receptacle contacts are press fit within the plastic receptacle housing, the metal front portions of the receptacle contacts have no space for axial expansion due to temperature changes. Thus, as the front portions of the receptacle contacts expand within the cavities, the front portions of the receptacle contacts may become distorted by their contact with cavity walls and push against the cavity walls causing cracks in the receptacle housing, and become disconnected from the plug contacts. 
     Therefore, a need exists for a board-to-board connector assembly that overcomes the above problems and addresses other concerns experienced in the prior art. 
     BRIEF SUMMARY OF THE INVENTION 
     Certain embodiments include an electric connector assembly having a housing with a chamber therein having an open end configured to receive a plug contact. The electric connector assembly includes a receptacle contact having a contact box on one end located in the chamber. The electrical connector has a contact pin on an opposite end extending from the chamber, and the contact box has a latch feature on a periphery thereof securing the contact box to the housing. The contact box has an open front end aligning with the open end of the chamber that is configured to receive a plug contact. The receptacle contact further includes a compliant section between the contact box and contact pin that is flexible to absorb vibrations introduced into the contact box and contact pin. 
    
    
     BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS 
     FIG. 1 illustrates a front isometric view of a plug housing formed according to an embodiment of the present invention. 
     FIG. 2 illustrates a front isometric view of a receptacle housing formed according to an embodiment of the present invention. 
     FIG. 3 illustrates a bottom isometric view of the plug housing of FIG.  1 . 
     FIG. 4 illustrates a top isometric view of the receptacle housing of FIG.  2 . 
     FIG. 5 illustrates a side isometric view of a receptacle contact formed according to an embodiment of the present invention. 
     FIG. 6 illustrates a bottom isometric view of the receptacle contact of FIG.  5 . 
    
    
     The foregoing summary, as well as the following detailed description of certain embodiments of the present invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings, certain embodiments. It should be understood, however, that the present invention is not limited to the arrangements and instrumentality shown in the attached drawings. 
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 illustrates a front isometric view of a plug housing  10  formed according to an embodiment of the present invention. The plug housing  10  includes a shroud header  14  formed from a top wall  18 , a bottom wall  30  and opposite end walls  22  extending perpendicularly outward from a rear wall  26  that collectively define a chamber  25 . Rectangular securing rails  34  extend inward from the top wall  18  proximate opposite ends of the top wall  18 . Likewise, a securing rail  34  extends inward from each end wall  22 . Planar retention bars  38  extend from the rear wall  26  into the chamber  25  and are suspended within the shroud header  14 . Screw blocks  40  extend from the rear wall  26  along the bottom wall  30  and include screw holes  44  that extend through the screw blocks  40  and the rear wall  26 . During assembly, screws are inserted into the screw holes  44  and are used to connect the plug housing  10  to a printed circuit board (not shown) or other electronic component. The shroud header  14  mateably receives a contact block  66  (FIG. 2) with the securing rails  34  orienting the contact block  66  within the shroud header  14  and the retention bars  38  aligning the contact block  66  with the shroud header  14  such that contact blades  42  and contact pins  54  are received within the contact block  66  without being bent. 
     The contact blades  42  extend through the rear wall  26  into the chamber  25  and are aligned in a row proximate and parallel to the top wall  18 . The contact blades  42  are retained within rectangular passages  46  extending through the rear wall  26 . The contact blades  42  include blade crossbeams  50  that extend outward from opposite sides of the contact blades  42 . During assembly, the contact blades  42  are inserted into the passages  46  through the shroud header  14  in the direction of arrow A until the blade crossbeams  50  engage, and are retained in, the passages  46 , thus leaving the contact blades  42  suspended within the shroud header  14 . 
     The contact pins  54  are also inserted through the rear wall  26  and are aligned in parallel rows extending along the bottom wall  30 . The contact pins  54  also include pin crossbeams  58  that extend outward from, either side of the contact pins  54 . During assembly, the contact pins  54  are inserted into the shroud header  14  in the direction of arrow A until the pin crossbeams  58  engage, and are retained in, passages  46  through the rear wall  26 , thus leaving the contact pins  54  suspended within the shroud header  14 . When the shroud header  14  mateably engages the contact block  66  (FIG.  2 ), the contact blades  42  and contact pins  54  are received into the contact block  66  to electrically communicate with receptacle contacts  110  and  162  (FIG.  4 ), respectively. 
     FIG. 2 illustrates a front isometric view of a receptacle housing  62  formed according to an embodiment of the present invention. The receptacle housing  62  includes the contact block  66  extending out from a rear wall  70 . A bottom wall  114  is formed along one edge of the rear wall  70 . The contact block  66  includes a top wall  74 , a bottom wall  78  and opposite end walls  82  extending out from a base  86  formed on the rear wall  70 . The top wall  74  includes rail channels  91  proximate opposite ends thereof. Each end wall  82  also includes a rail channel  91 . The contact block  66  includes a front surface  94  having long thin beam cavities  98  therein. When the plug housing  10  (FIG. 1) and the receptacle housing  62  are mated, the shroud header  14  (FIG. 1) receives the contact block  66 . As the shroud header  14  receives the contact block  66 , the rail channels  91  in the top wall  74  receive and retain the securing rails  34  (FIG. 1) on the top wall  18 , and the rail channels  91  in the end walls  82  receive and retain the securing rails  34  on the end walls  22 . Likewise, the beam cavities  98  receive and retain the retention bars  38  (FIG. 1) on the plug housing  10 . 
     The front surface  94  is formed with a plurality of rectangular blade cavities  102  extending therethrough and aligned in a row proximate and parallel to the top wall  74 . The blade cavities  102  contain metal contact boxes  106  that form part of the receptacle contacts  110 . One end of the receptacle contacts  110  extends through a rear side  71  of the rear wall  70  and into blade cavities  102  in the contact block  66 . An opposite end of the receptacle contacts  110  extends down to the bottom wall  114  oriented perpendicular to the rear wall  70 . In operation, the row of blade cavities  102  and contact boxes  106  receive corresponding rows of contact blades  42  (FIG. 1) that electrically connect with the receptacle contacts  110  at the contact boxes  106 . 
     The front surface  94  of the contact block  66  also includes rectangular pin cavities  118  aligned in parallel rows. The pin cavities  118  contain metal contact boxes  122  formed on ends of receptacle contacts  162  (FIG.  4 ). One end of the receptacle contacts  162  extends through the rear side  71  of the rear wall  70  into the contact block  66 . An opposite end of the receptacle contacts  110  extends down to the bottom wall  114 . The pin cavities  118  and contact boxes  122  receive corresponding contact pins  54  (FIG.  1 ), until the contact pins  54  electrically connect with the receptacle contacts  162  (FIG. 4) through the contact boxes  122 . 
     FIG. 3 illustrates a bottom isometric view of the plug housing  10  of FIG.  1 . The contact blades  42  and contact pins  54  include tail ends  126  that extend outward through a bottom surface  130  of the rear wall  26  and are aligned in rows. Board posts  134  extend out from the bottom surface  130  of the rear wall  26 , and a rectangular board seal  138  wraps along a peripheral of the bottom surface  130 . The tail ends  126  are soldered to the printed circuit board (not shown), and the board posts  134  are received and retained in apertures in the printed circuit board, thus securing the plug housing  10  to the printed circuit board. The board seal  138  forms a seal between the rear wall  26  and the printed circuit board to prevent contaminants from affecting the contact blades  42  and contact pins  54 . 
     FIG. 4 illustrates a top isometric view of the receptacle housing  62  of FIG.  2 . Rectangular securing blocks  144  extend outward from the rear wall  70  and are connected to the bottom wall  114 . The lower side of the bottom wall  114  includes bottom posts  174 . An L-shaped contact chamber  142  extends from the rear side  71  of the rear wall  70  along the bottom wall  114  and includes an overhang block  146 . The blade cavities  102  extend from the front surface  94  of the contact block  66  through the rear wall  70  and the overhang block  146 . The receptacle contacts  110  include front pin portions  150  and rear pin portions  154 . The contact chamber  142  also includes a lower wall  158 . The pin cavities  118  extend from the front surface  94  of the contact block  66  through the rear wall  70  and the lower wall  158 . The receptacle contacts  162  are smaller than the receptacle contacts  110  and include front pin portions  166  and rear pin portions  170 . 
     During assembly, the receptacle contacts  110  and  162  are unbent and are inserted into the blade cavities  102  and pin cavities  118 , respectively, through the front surface  94  in the direction of arrow B. The contact boxes  106  and  122  (FIG. 2) are press fit within the blade and pin cavities  102  and  118 , respectively. The front pin portions  150  and  166  extend out of the blade and pin cavities  102  and  118 , respectively, of the contact chamber  142 . The receptacle contacts  110  and  162  are then bent so that the rear pin portions  154  and  170  are perpendicular to the front pin portions  150  and  166 , respectively. The bottom wall  114  has post apertures (not shown) and is fastened to the securing blocks  144  with the post apertures receiving the bottom posts  174 . The rear pin portions  154  and  170  extend through holes (not shown) in the bottom wall  114  leaving tail ends  294  (FIG. 5) exposed under the bottom wall  114 . 
     The receptacle housing  62  is positioned on a printed circuit board (not shown) with the bottom posts  174  being received and retained in apertures in the printed circuit board. The tail ends  294  (FIG. 5) of the receptacle contacts  110  and  162  are soldered to the printed circuit board. The receptacle housing  62  is then mated with the plug housing  10  (FIG. 1) so that electric signals are sent from the printed circuit board attached to the receptacle housing  62  to the printed circuit board attached to the plug housing  10 , and vice versa. 
     FIG. 5 illustrates a side isometric view of a receptacle contact  110 . The receptacle contact  110  is similar in structure to the receptacle contact  162  (FIG.  4 ), but different in size. The receptacle contact  110  is generally representative of the receptacle contact  162  and thus only the receptacle contact  110  is discussed in detail. The receptacle contact  110  includes the contact box  106  situated at a front end  198  of the receptacle contact  110 . The contact box  106  includes opposite side walls  202  and  206  extending upward from a bottom wall  210 . The side walls  202  and  206  are formed integral with top walls  214  and  222 , respectively. The top walls  214  and  222  are bent toward one another in an overlapping arrangement. A front portion  226  of the top wall  222  extends inward from the side wall  206  and is separated from the top wall  214  by gaps  230 . The front portion  226  of the top wall  222  is flared upward to be aligned in a common horizontal plane  238  with the top wall  214 . 
     The overlapping top walls  214  and  222  include overlapping apertures  232  and  234 , respectively, located generally in the centers thereof. The apertures  232  and  234  receive a latch (not shown) extending downward and into the apertures  232  and  234  from an interior surface of a top wall in the blade cavity  102  (FIG.  4 ). The latch extends through the apertures  232  and  234  to hold the contact box  106  in a fixed position within the blade cavity  102 . The latch prevents the top wall  214  and a rear portion  218  of the top wall  222  from sliding relative to each other. The overlapping top walls  214  and  222  reinforce the structural integrity of the contact box  106  in order to better withstand pressures applied to the contact box  106  by the walls of the blade cavity  102  and by engagement with contact blades  42  (FIG.  1 ). 
     A spring prong  242  is formed integral with and extends from the bottom wall  210  at the front end  198 . The spring prong  242  is bent at an acute angle rearward into a contact cavity  246  and projects toward the top walls  214  and  222 . When the blade cavity  102  receives a contact blade  42  (FIG.  1 ), the contact blade  42  enters the contact box  106  at the front end  198  in the direction of arrow E. As the contact blade  42  enters the contact box  106 , the contact blade  42  slides up along the spring prong  242  until the contact blade  42  is pinched between the spring prong  242  and the top wall  222 . The contact blade  42  is thus held in a fixed position in the contact box  106  and may be slidably removed when pulled out of the contact box  106  in the direction of arrow F. 
     The side walls  202  and  206  include retention recesses  190  that engage catches (not shown) extending inward from interior side walls in the blade cavity  102  as the receptacle contact  110  is inserted into the blade cavity  102 . The catches and retention recesses  190  cooperate to retain the contact box  106  within the blade cavity  102  in a fixed position. Stop beams  298  are formed on and extend rearward from rear ends  199  of the side walls  202  and  206 . The stop beams  298  engage and resist a compliant section  250  when the compliant section  250  shifts toward the contact box  106 , thus preventing the compliant section  250  from damaging or dislodging the contact box  106 . 
     A connection board  326  extends rearward from the compliant section  250  to a cylindrical pin holder  282 . The pin holder  282  is crimped about the front pin portion  150  proximate a first end to form a mechanical weld. The pin holder  282  secures the front pin portion  150  to the compliant section  250  so that an electric signal is conveyed between the contact box  106  and the tail end  294 . A U-shaped retention flange  286  is wrapped around the front pin portion  150  proximate the pin holder  282 . When the receptacle contact  110  is positioned within the blade cavity  102  (FIG.  4 ), ridged surfaces  290  of the retention flange  286  frictionally engage an interior top wall (not shown) of the blade cavity  102  within the overhang block  146  (FIG. 4) and retain the receptacle contact  110  within the blade cavity  102 . 
     FIG. 6 illustrates a bottom isometric view of the receptacle contact  110  of FIG.  5 . The bottom wall  210  includes a cross portion  302  extending from one end of an intermediate portion  310  and a cross portion  306  extending from the opposite end of the intermediate portion  310 . The cross portion  302  is separated from the side walls  202  and  206  by bottom gaps  314 . The bottom gaps  314  allow the cross portion  302  to be biased in the directions of arrow K or arrow L as the contact blade  42  (FIG. 1) enters the contact box  106  and engages the spring prong  242 . Thus, the bottom gaps  314  allow for easier insertion of the blade contact  42 . 
     The compliant section  250  is connected to the bottom wall  210  of the receptacle contact  110  and includes side walls  258  having leading side sections  251  extending from a cross portion  306  of the bottom wall  210  to a top wall  254  of the compliant section  250 . The compliant section  250  is formed at one end integral with the bottom wall  210  of the contact box  106  and at an opposite end integral with the connection board  326 . Side notches  262  separate the leading side sections  251  from trailing side sections  253 . The bottom wall  210  of the compliant section  250  is also divided by a bottom gap  263  into lead and trailing bottom sections  265  and  267 , respectively. The lead bottom section  265  includes a plurality of stop projections  322  extending toward the trailing bottom section  267  within the bottom gap  263 . The compliant section  250  is separated from the contact box  106  by a contact gap  270  that extends across the top wall  214  and downward along the side walls  202  and  206  along a diagonal line in a general S-shape. The contact gap  270  includes lower lead gap sections  271  extending parallel to one another along the bottom wall  210 . The lower lead gap sections  271  are directed forward toward the front end  198  of the contact box  106  and are flared at ends  273  (FIG.  6 ). 
     In operation, the compliant section  250  allows vibrations traveling along the receptacle contact  110  from the front and rear pin portions  150  and  154  (FIG. 4) to be absorbed without dislodging or damaging the contact box  106  press fitted within the blade cavity  102  (FIG.  4 ). For example, when vibrations caused by external forces affecting the front pin portion  150  (FIG. 4) travel along the receptacle contact  110  in the direction of arrow F, the trailing side sections  253  extend in the direction of F into the side notches  262  and bottom gap such that the stop projections  322  may engage the connection board  326 . The vibrations are partially absorbed by the stop projections  322  and the side notches  262  before reaching the leading side sections  251 . As the vibrations travel along the leading side sections  251 , the leading side sections  251  and top wall  254  axially float in the direction of arrow F into the contact gap  270 . The contact gap  270  thus narrows. The leading side sections  251  may contact the stop beams  298 , however even then the vibrations are greatly reduced and do not dislodge or damage the contact box  106 . The contact gap  270  allows the compliant section  250  to float in either direction along a longitudinal axis  274  that extends along the length of the contact box  106 , and in either direction along transverse axes  278  and  279  that extends perpendicular to the length of the contact box  106 . 
     For example, as the connection board  326  floats along the transverse axis  278  in the direction of arrow K, the side walls  258  flex in the direction of arrow M proximate the side notches  262 . Alternatively, as the connection board  326  floats along the transverse axis  278  in the direction of arrow L, the side walls  258  flex in the direction of arrow N proximate the side notches  262 . Similarly, as the cross portion  306  floats along the transverse axis  278  in the direction of arrow K, the bottom wall  210  flexes in the direction of arrow M proximate the ends  273  of the lower lead gap sections  271 . Alternatively, as the cross portion  306  floats along the transverse axis  278  in the direction of arrow L, the bottom wall  210  flexes in the direction of arrow N proximate the ends  273  of the lower lead gap sections  271 . 
     Likewise, as the connection board  326  floats along the transverse axis  279  in the direction of arrow P, the side walls  258  flex in the direction of arrow Q proximate the side notches  262 . Alternatively, as the connection board  326  floats along the transverse axis  279  in the direction of arrow R, the side walls  258  flex in the direction of arrow V proximate the side notches  262 . Additionally, as the leading side sections  251  float along the transverse axis  279  in the direction of arrow P, the cross portion  306  flexes in the direction of arrow Q between the lower lead gaps  271 . Alternatively, as the leading side sections  251  float along the transverse axis  279  in the direction of arrow R, the cross portion  306  flexes in the direction of arrow V between the lower lead gaps  271 . 
     The side notches  262  and contact gap  270  similarly accommodate axial float of the compliant section  250  stemming from thermal expansion. For example, as the metal of the compliant section  250  expands, the compliant section  250  axially floats toward the contact box  106  in the direction of arrow F, narrowing the contact gap  270 , but not contacting the contact box  106 . 
     Additionally, the side notches  262  and bottom gap  263  accommodate the twisting of the trailing side sections  253  and connection board  326  about the longitudinal axis  274 . For example, as the connection board  326  or trailing side sections  253  are twisted in the direction of either arrow T or S about the longitudinal axis  274 , the top wall  254  and trailing side section  253  flex in the same direction proximate the side notches  262 . Likewise, the contact gap  270  and the lower lead gap sections  271  accommodate the twisting of the compliant section  250  about the longitudinal axis  274 . For example, as the compliant section  250  is twisted in the direction of either arrow T or S about the longitudinal axis  274 , the cross portion  306  flex in the same direction between the lower lead gap sections  271 . Thus, vibrations causing the connection board  326  or compliant section  250  to twist are accommodated without affecting the contact box  106 . 
     The receptacle housing confers the benefit of an axially floating receptacle contact. When the compliant section receives vibrations from the pin portions or expands due to temperature changes, the compliant section may move axially within the blade cavity into gaps separating the compliant section from the contact box. Thus vibrations and thermal expansion are less likely to loosen or damage the contact boxes or affect the electrical connection between the contact boxes and the contact blades or pins. 
     While the invention has been described with reference to certain embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.