Abstract:
A dual beam receptacle terminal is shown having a generally box shaped receptacle contact where first and second contact portions are reversely bent from an upper wall to overlap within an interior of the receptacle contact. The first and second contact portions also extend in a cantilevered fashion from the upper wall. A spherical dimple is provided on the upper of the two reversely bent contact portions in the location of the overlapped portion. Contact stop portions are provided on the side walls of the receptacle contact portion which engage the contact stop portions on the receptacle sidewalls. A coverwall is provided overlapping the upper wall which forms a clean seam with the sidewall from which the upper wall extends.

Description:
BACKGROUND OF THE INVENTION 
   The invention relates to an electrical contact for use with a mating pin or blade contact to join electrical wires or other electrical conductors together. 
   It is well known in the art of electrical connectors to provide a receptacle contact or terminal for the receipt of a pin or blade contact where the receptacle contact has contact beams which extend from a receptacle body and are profiled to electrically engage a pin or blade contact upon insertion thereof. This contact between the receptacle contacts and its corresponding pin or blade contact interconnects the two pin and receptacle contacts and results in an electrical connection between the two and their associated mating conductors. 
   Multiple different requirements are involved in such an electrical device, particularly when used in a multi-position connector, for example when used in an automotive connector. 
   First, it is a requirement to provide a normal force between the receptacle contact and its associated pin or blade contact in order to provide the electrical connection between the two. In an effort to increase this normal force between the contact and the associated pin or blade contact, it is known to provide such devices as backup springs and other devices to enhance the normal force between the contact and its associated pin or blade contact. However in the instance of a multi-position connector, this enhanced normal force resultantly corresponds with an increased mating force as well which can negatively affect the overall objective. Suffice it to say that it is a delicate balance between the normal force of the mated connection, versus the mating force between the associated pin and receptacle contacts. 
   Other requirements that are necessary for multi-position connectors, is that the contact must be capable of sealing. In some cases, a discreet wire seal is crimped to individual contacts around individual wires, and the contact and its associated seal are inserted into an aperture in a connector housing. In other cases a rear seal is provided having a multitude of apertures through which individual contacts are inserted where the contacts are larger than the hole through which they extend, as the holes are nominally provided to sealingly engage the discreet wire to which they are connected. 
   One electrical receptacle is shown in U.S. Pat. No. 5,791,945 (incorporated herein by reference) where dual beam contacts are provided in a reversely bent sense such that their free ends overlap, with one beam forming a primary contact and the other beam providing a backup or secondary contact. In other words when a pin is inserted into the receptacle, the pin engages the primary contact and the insertion of the pin causes the deflection of the primary contact to a position where it engages the secondary and backup contact at which point the two travel together under an increased normal force. 
   While this concept is sound for some contact scenarios, as the contacts are reduced, some modifications are required. First, the contact has an anti-overstress feature which is stamped and struck from the top wall of the receptacle which extends downwardly to form an engagement lug with the secondary contact backup portion. Thus the primary and secondary contacts cannot be deflected beyond the position where the secondary contact engages its corresponding lug. As mentioned above, while this concept is sound for some contact sizes, as the contact is reduced in its overall dimensions, having the overstress feature extend from the top wall can cause an issue with dimensional stack up, as the receptacle “box” and the various metal thicknesses add to the dimensional disparity. 
   Also, the first and second contact arms, when used in a smaller dimension contact, can cause a “spiking” effect when the first and second contacts first engage each other. Said differently, due to the geometries of the primary and secondary contacts, when the primary contact makes engagement with the secondary contact, it engages along a line contact at the front edge of the secondary contact, the two then travel together until the two contacts are substantially parallel and overlapping, and then move to a position where the two are along a line contact engaging the rear edge of the primary contact. The point where the two contacts are in a flat position can cause a spiking of mating force due to the increased force required to overcome this flattened position. 
   SUMMARY OF THE INVENTION 
   The subject invention provides an electrical terminal comprising a body portion comprising a lower wall, an upper wall, and side walls connecting the upper and lower walls. The upper and lower walls and the side walls forms a body interior portion. A first contact portion extends from one of the walls and is reversely bent into the body interior portion. A second contact portion extends from the one wall, and is reversely bent into the body interior portion. The first and second contacts extending in opposite and overlapping relation. At least one indentation extends into the body interior portion, and extends from a wall transverse to the one the wall, the indentation providing a stop position for the first contact portion. 
   The first and second contacts may extend from the upper wall. The indentation may extend inwardly from one of the side walls. The indentation may be sheared along a lower edge and formed inwardly to define a downwardly extending cup-shaped portion, with the sheared edge forming the stop position. The first contact portion, in the location of the indentation, may form a T-shaped portion. 
   In another aspect of the invention, an electrical terminal, comprises a body portion comprising a lower wall, an upper wall, and side walls connecting the upper and lower walls, the upper and lower walls and the side walls forming a body interior portion. A first contact portion extends from one of the walls and is reversely bent into the body interior portion. A second contact portion extends from the one wall, and is reversely bent into the body interior portion, the first and second contact portions extending in opposite and overlapping relation. The first and second contact portions extend from the one wall in a cantilevered fashion. 
   The cantilevered portions on the first and second contact portions may extend in the same plane as the one wall. The first and second contact portions may extend from the upper wall. The lower wall may include a lower contact portion formed inwardly in an axial position adjacent the first and second contact portions. The second contact portion may include a crowned portion, extending towards, and in the overlapping portion with, the first contact portion. 
   In yet another embodiment, an electrical terminal, comprises a body portion comprising a lower wall, an upper wall, and side walls connecting the upper and lower walls, the upper and lower walls and said side walls forming a body interior portion. A first contact portion extends from one of the walls and is reversely bent into the body interior portion. A second contact portion extends from the one wall, and is reversely bent into the body interior portion, the first and second contact portions extending in opposite and overlapping relation. The second contact portion includes a crowned portion, extending towards, and in the overlapping portion with, the first contact portion. 
   The crowned portion may be arcuate, and profiled such that the first and second contact portion pivot about the arcuate portion, as the first and second contact portions are deflected. The crowned portion may be defined as a spherical dimple. The first and second contact portions may extend from the upper wall. The lower wall may include a lower contact portion, formed inwardly in an axial position adjacent the first and second contact portions. The first and second contact portions may extend from the one wall in a cantilevered fashion, and the cantilevered portions on the first and second contact portions may extend in the same plane as the one wall. 
   In a final embodiment, an electrical terminal comprises a lower wall portion, and a first sidewall portion upstanding from the lower wall and having an upper edge. A second sidewall portion upstands from an opposite edge of the lower wall portion. A contact portion extends integrally from the upper edge and extends inwardly and between the lower wall and first and second sidewalls, leaving the remaining upper edge exposed. An outer wall, overlaps the contact portion, and includes a downwardly extending lip, with a downwardly extending edge coinciding with the upper edge. 
   The contact portion may comprise a strap portion extending from the upper edge. The contact portion may further comprise a first contact portion extending from the strap portion, and being reversely bent into an interior of the walls. The contact portion may further comprise a second contact portion extending from the strap portion and being reversely bent in an opposite sense as the first contact, with the first and second contacts extending in opposite and overlapping relation. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a front perspective view of the electrical receptacle terminal of the present invention; 
       FIG. 2  is a lower perspective view of the terminal shown in  FIG. 1 ; 
       FIGS. 3-6  show various perspective views of the receptacle terminal portion of the terminal; 
       FIG. 7  top plan view of the terminal of  FIG. 1 , with the terminal connected to the carrier strip; 
       FIG. 8  is a cross-sectional view shown through lines  8 - 8  of  FIG. 7 ; 
       FIG. 9  is an enlarged view of the portion denoted in  FIG. 9 ; 
       FIG. 10  shows the receptacle terminal of  FIG. 1  in the flat blank condition; 
       FIG. 11  shows a side view of the terminal of  FIG. 7 ; 
       FIG. 12  shows a cross sectional view through lines  12 - 12  of  FIG. 11 ; 
       FIG. 13  is a view similar to that of  FIG. 9  showing the first and second contact portions in initial contact; 
       FIG. 14  shows the movement of the first and second contact portions into an intermediate position prior to their stop position; 
       FIG. 15  shows the first and second contact portions moved to their extreme position; 
       FIG. 16  shows a perspective view of the receptacle terminal portion of another embodiment of the terminal; 
       FIG. 17  shows a perspective view of the opposite side of the receptacle terminal portion of  FIG. 16 ; and 
       FIG. 18  shows the perspective view of  FIG. 16 , partially cut away. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   With respect first to  FIGS. 1 and 2 , an electrical receptacle terminal is shown at  2  including the receptacle contact portion  4 , a wire crimp section at  6  and a strain relief section at  8 . 
   With respect now to  FIGS. 3 through 6 , the construction of the receptacle contact portion  4  will be described in greater detail. As shown in  FIG. 3 , the receptacle contact portion  4  includes a lower wall  10 , sidewalls  12 ,  14 , an upper wall  16  and a cover wall  18 , which together form a body interior portion. With reference again to  FIG. 2 , lower wall  10  includes an inwardly directed contact portion at  20  defined as a beam extending between wall parts  22  and  24  and having separations at  26 ,  28 . The contact portion  20  is thereafter inwardly directed and can act as a resilient contact extending between the wall parts  22 ,  24 . 
   With reference again to  FIG. 3 , sidewall  12  is shown including a contact stop portion  30 , which will be described herein which includes a lower cut-out portion at  32  and an inwardly directed spherically-shaped indentation at  34  defining a lower engagement edge at  36 . Sidewall  12  further includes a forward recessed section at  38  and a rearward recessed section at  40 . The upper wall  16  itself extends integrally from sidewall  12 , and both the forward  38  and rearward  40  recessed sections are recessed from the upper wall  16 , as will be discussed further herein. Finally, sidewall  12  can include an aligning lug such as  42  for aligning the terminal with an associated housing cavity (not shown). 
   With reference now to  FIG. 4 , sidewall  14  includes a contact stop-portion  50  including a cut-out portion at  52  and a strap portion at  54  extending above the cut-out portion  52  and inwardly directed to define a lower engagement edge at  56 . Sidewall  14  further includes a recessed section at  58 , intermediate recessed sections  38 ,  40  of sidewall  12 , as will be further discussed herein. Finally, sidewall  14  can also include an aligning lug such as  60  again for aligning the terminal with a housing cavity. 
   With reference now to  FIGS. 3 through 7 , upper wall  16  is shown spanning between sidewalls  12  and  14  and integrally connected to sidewall  12 . As shown in  FIGS. 4 ,  6 , and  7 , upper wall  16  is shown received in recessed section  58  of sidewall  14 . With reference now to  FIG. 8 , upper wall  16  is shown in section yet includes a contact assembly  70  extending integrally from upper wall  16  to include a first or primary contact portion  72  and a second or secondary contact portion  74 . 
   With reference still to  FIG. 8 , first contact portion  72  includes a cantilever portion  76  extending integrally from front edge  78  of upper wall  16 . First contact portion  72  further includes a reversely bent portion  80 , reversely bent through radiused portion  82 . Finally, first contact portion  72  includes extension portions  84  extending on both sides of reversely bent portion  80  to form a T-shaped portion as will be described further herein. 
   With reference still to  FIG. 8 , second contact portion  74 , includes a cantilevered portion at  90  extending integrally from a rear-edge  92  of upper wall  16  and includes a reversely bent portion  94 , reversely bent through radiused portion  96 . As best shown in  FIG. 9 , the free-end of reversely bent portion at  94  is crowned, to define a spherically shaped dimple  98  ( FIG. 9 ) positioned over reversely bent portion  80 , in the overlapping region of reversely bent portions  80 ,  94 . 
   With reference again to  FIG. 3 , cover wall  18  includes a recessed section at  100  with downwardly extending lip portions  102 ,  104  which flank the upper wall  16  and extend into the recessed sections  38  and  40 , as described herein. Cover wall  18  further includes a downwardly extending flap  108  to assist in directing a pin on insertion thereof. With the product as described above, the manufacturing of the terminal will now be described with reference to  FIG. 12 . 
   As shown in  FIG. 10 , the terminal is shown in a flat blank condition, from the inside surface of the terminal. The blank is stamped to include the shape as shown, and then formed to define such features as the inwardly directed contact portion  20 , the stop portions  30 ,  50 , the aligning lugs  42 ,  60  and the dimple  98 . The contact formation would include the reversely bending of contact portions  72  and  74 , and then the folding of the terminal into the square receptacle form, by folding the contact portions along lines  118 ,  120 ,  122 , and  124 , and into the configuration of  FIGS. 1 and 2 . 
   Note that  FIG. 10  also provides a good view of some features not seen in the previous views. First,  FIG. 10  shows extension portions  84 , which are wider than the associated reversely bent portion ( FIG. 8 ) which form a T-shaped portion adjacent the end. Secondly,  FIG. 10  shows second contact portion  74  including a necked-down section defined by side edges  126 . 
   With respect to  FIGS. 10 through 15 , the operation of the receptacle terminal will now be described. It should be appreciated from the previous discussion, that contact assembly  70  together with inwardly directed contact  20 , together provide opposed contacts for receipt of a pin or other male component. 
   With respect first to  FIG. 13 , as a pin is first inserted, reversely bent portion  80  begins to rotate in the counterclockwise sense as viewed in  FIG. 13  (see arrow A) to the position where the reversely bent portion  80  contacts the spherical dimple  98 . Up until this point, it should be appreciated that the first contact portion  72  and more particularly, the reversely bent portion  80  moves alone. Further insertion of the pin, as shown in  FIG. 14 , causes the two reversely bent portions  80 ,  94  to travel together, also causing the reversely bent portion  80  to pivot around the spherical dimple  98 . 
   Furthermore, the reversely bent contact portion  94 , passes through the contact stops  30 ,  50 . This is due to the necked down surfaces  126  discussed with reference to  FIG. 10 . This is shown in cross section in  FIG. 12 , where the surfaces  126  are shown being received between the contact stops  30 ,  50 . As shown in  FIG. 12 , the necked-down section defined by surfaces  126  allow second contact portion  74  to be positioned intermediate indentations  34  and  54 . 
   Rather, extension portions  84  of reversely bent portion  80 , are defined wider than engagement edges  36 ,  56 , (again seen in  FIG. 12 ) and therefore will contact the engagement edges  36 ,  56  upon upward biasing of first contact portion  72  to that point.  FIG. 15  also shows the two reversely bent portions  80 ,  94  in their final position, where extensions  84  contact the engagement edges  36  of stop portion  30 . 
   It should also be noted that during the progression from  FIGS. 13 to 15 , reversely bent portion  80  pivots around spherical dimple  98  preventing the arms from engaging in a back-to-back parallel manner. This prevents spiking in the insertion force during the insertion of the contact pin. Also as the stop portions  30 ,  50  are provided on the side walls, the vertical positioning of the stop edges  36 ,  56  is more precisely defined. Having the overstress feature extend from the side walls prevents any problems with dimensional stack up, because the tolerances of the receptacle “box” shape/dimensions, and the various metal thicknesses are not at issue and therefore do not accumulate. Also as viewed in  FIG. 8 , the cantilevered beam portions  76 ,  98  extend from the upper wall portion  16  and can also move upon resilient movement of reversely bent portions  80 ,  94  further reducing the stresses in the contact assembly  70 . Finally, and with reference again to  FIG. 3 , the contact receptacle  4  is defined with a clean body for insertion through a seal. As lips  102 ,  104  extend downwardly into the associated recesses,  38 ,  40 , no sheared edge is positioned where it may cut a seal during the insertion of the contact through the seal. 
   With reference now to  FIGS. 16-19 , an alternate embodiment of the terminal contact portion is shown. With reference first to  FIG. 16 , the receptacle contact portion is shown as  204  and includes a lower wall  210 , sidewalls  212 ,  214 , an upper wall  216  and a cover wall  218 , which together form a body interior portion. With reference again to  FIG. 16 , lower wall  210  includes an inwardly directed contact portion at  220 , which is substantially similar to inwardly directed contact portion  20 . 
   With reference still to  FIG. 16 , sidewall  214  includes a contact stop-portion  250  including a cut-out portion at  252  and a strap portion at  254  extending above the cut-out portion  252  and inwardly directed to define a lower engagement edge at  256 . Sidewall  214  further includes a recessed section at  258 , to receive upper wall  216  and further includes an aligning lug such as  260  for aligning the terminal with a housing cavity. 
   With reference now to  FIGS. 16-18 , upper wall  216  is shown spanning between sidewalls  212  and  214  and integrally connected to sidewall  212 . As shown in  FIG. 16 , upper wall  216  is shown received in recessed section  258  of sidewall  214 . With reference now to  FIG. 18 , upper wall  216  is shown in section yet includes a contact assembly  270  extending integrally from upper wall  216  to include a first or primary contact portion  272  and a second or secondary contact portion  274 . The contact portions  272  and  274  are substantially identical to contact portions  72 ,  74 . 
   The free-end of reversely bent portion  274  is crowned, to define a spherically shaped dimple  280  ( FIG. 18 ) positioned over contact portion  272 , in the overlapping region of contact portions  272 ,  274 . 
   As mentioned above, contact stop portion  250  is substantially similar to contact stop portion  50 , however sidewall  212  does not have a contact stop portion analogous to stop portion  30 . Rather, sidewall  212  only includes a visual opening  300  ( FIG. 7 ) for observing the condition and/or locations of contact portions  272 ,  274 . Rather than having a contact stop portion analogous to contact stop portion  30 , tab portion  302  extends downwardly from upper wall  216  and extends downwardly towards contact portion  274 . In this manner, stop portion  250  acts as a primary stop for primary contact portion  272 , and tab portion  302  acts as a secondary contact stop for secondary contact portion  274 .