Patent Publication Number: US-6210240-B1

Title: Electrical connector with improved terminal

Description:
FIELD OF THE INVENTION 
     This invention generally relates to the art of electrical connectors and, particularly, to an electrical connector having an improved terminal, such as a power terminal for mating with a blade terminal. 
     BACKGROUND OF THE INVENTION 
     Generally, an electrical connector includes some form of insulative or dielectric housing which mounts one or more conductive terminals. The housing is configured for mating with a complementary mating connector or other connecting device which, itself, has one or more conductive terminals. A connector assembly typically includes a pair of mating connectors, such as plug and receptacle connectors sometimes called male and female connectors. The interengaging terminals of the connectors, themselves, may be male and female terminals. 
     One type of electrical connector is a power connector which mounts one or more power terminals. One type of power terminal, as shown in FIG. 6a and 6b as opposed terminals, is a female terminal adapted for receiving and engaging a power terminal blade of a complementary mating connector or other connecting device. The female terminal is configured for engaging both opposite sides of the power terminal blade. Heretofore, typical female terminals of this type included a redundant pair of contact walls on opposite sides of the terminal blade, each wall having a plurality of bent contact arms for engaging a respective side of the terminal blade. For instance, the contact arms may be bent back from a top edge of the contact wall. The opposite edge of the contact wall is located at a terminating face of the connector and may include a plurality of tail portions for insertion into appropriate holes in a printed circuit board, for instance. 
     One problem with prior art connectors as described above is that the terminals include a pair of separate contact portions on opposite sides of the power terminal blade. If one of the contact portions is not fully inserted into the connector housing or is not inserted at all, the other contact portion still may pass an electrical continuity inspection but will result in a lower current carrying capacity since both contact portions are required for an effective electrical engagement. Other problems with such two-part female terminals for receiving terminal blades involves the latch in the base which will reduce current flow, will not allow for a close side by side placement of the terminals, and will not provide a precise location and a stable engagement in the housing. The present invention is directed to solving these various problems and providing an efficient connector having an improved female terminal of the character described. 
     SUMMARY OF THE INVENTION 
     An object, therefore, of the invention is to provide a new and improved electrical connector for mating with a complementary connecting device having a blade terminal. 
     Another object of the invention is to provide a new and improved female terminal for receiving and engaging the blade terminal. 
     In the exemplary embodiment of the invention, an electrical connector is shown to include a dielectric housing having a front mating face, an elongated terminal-receiving cavity with an open end through the mating face for insertion therethrough of the blade terminal, and a locking ledge on an end wall of the cavity. A conductive female terminal is received in the cavity and includes a pair of elongated side walls joined in spaced relation by at least one end wall. A plurality of flexible contact arms are folded back over each side wall from an upper edge thereof nearest the open end of the cavity for engaging a respective side of the blade terminal. A locking finger projects from the end wall of the terminal and is engageable with the locking ledge on the end wall of the terminal-receiving cavity. 
     According to one aspect of the invention, the dielectric housing includes a rear terminating face through which the terminal is inserted into the terminal-receiving cavity. Complementary interengaging abutting shoulders are provided between the terminal and the housing to define the depth of insertion of the terminal into the cavity. The abutting shoulders are between the one end wall of the terminal and the housing. As disclosed herein, the terminal includes a pair of the end walls each having an abutting shoulder engageable with a respective abutting shoulder on opposite end walls of the terminal-receiving cavity. 
     Other features of the invention including the terminal being stamped and formed of sheet metal material, and the flexible contact arms of the terminal being of thinner material than the side walls thereof. The terminal includes a plurality of terminating tails projecting from a lower edge of each side wall of the terminal. 
     Other objects, features and advantages of the invention will be apparent from the following detailed description taken in connection with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The features of this invention which are believed to be novel are set forth with particularity in the appended claims. The invention, together with its objects and the advantages thereof, may be best understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements in the figures and in which: 
     FIG. 1 is a fragmented, cut-away perspective view of an electrical connector embodying the concepts of the invention; 
     FIG. 2 is a perspective view of one of the female terminals according to the invention; 
     FIG. 3 is a side elevation view of the female terminal; 
     FIG. 4 is an end elevation view of the female terminal; 
     FIG. 5 is a top plan view of the female terminal; and 
     FIGS. 6 a  and  6   b  disclose a perspective view of two opposed female terminals in the prior art. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the drawings in greater detail, and first to FIG. 1, the invention is embodied in an electrical connector, generally designated  12 , as well as in the configuration of a female terminal, generally designated  14 , mounted in the connector. Generally, the connector and the terminal(s) are adapted for receiving and electrically engaging one or more terminal blades (not shown) from a power connector or other connecting device. Such a terminal blade simply is a flat member, typically of metal material, having opposite contact sides. 
     With that understanding, electrical connector  12  includes an insulative or dielectric housing  16  which may be a one-piece structure molded of plastic material or the like, for instance. The housing includes a front mating face  18  and a rear terminating face  20  which also may be a mounting face for mounting the connector on a printed circuit board. The housing has a plurality of elongated terminal-receiving cavities  22  for receiving terminals  14 . Each cavity includes an open rear or bottom end  24  in terminating face  20  of the housing and into which a respective one of female terminals  14  is inserted in the direction of arrow “A”. Each cavity includes an open top end  26  into which a mating blade terminal is inserted in the direction of arrow “B”. Each cavity includes opposite end walls  28 . Although FIG. 1 is broken away to show only one end wall  28  of one cavity  22 , each end wall includes a locking ledge  30  and an abutment shoulder  32 . Finally, holes  34  are provided through shoulder areas  36  of housing  16  for receiving appropriate core pins used to form locking ledges  30  during molding of the housing. 
     It can be seen in FIG. 1 that a plurality of open top ends  26  of the terminal-receiving cavities are provided in mating face  18  of connector housing  16  for receiving a ;plurality of terminal blades for electrical engagement with a plurality of female terminals  14  mounted in the connector housing. According to the invention, connector  12  may mount a single terminal  14  or a plurality of terminals, as shown. Therefore, a considerable portion of the following description will be directed to a single terminal  14  received in a single cavity  22 , although it should be understood that the remaining cavities have constructions similar to that described above and the remaining terminals have constructions similar to that described below. 
     With that understanding, reference is made FIGS. 2-5 in conjunction with FIG. 1, wherein a single female terminal  14  is shown for receiving a terminal blade in the direction of arrow “B” (FIG.  2 ). Each female terminal is stamped and formed of sheet metal material and includes a pair of elongated, planar side walls  38  and a pair of end walls  40  and  42 . End wall  40  is integral with and joins side walls  38  and, in essence, defines the spacing of the side walls. End wall  42  spans the side walls, but a seam  44  is formed at a distal end of side wall  42  during the forming operation of the terminal. Each side wall  38  includes a lower edge  46  and an upper edge generally at  48 . A plurality of contact arms  50  are folded back over each side wall  38  from upper edge  48  thereof. The contact arms are bowed to form opposing contact points  50 a which engage opposite sides of the mating terminal blade. A plurality of terminating or solder tails  52  project from lower edge  46  of each side wall  38 . The solder tails project beyond terminating face  20  of housing  16  as seen in FIG. 1, whereby the tails are insertable into appropriate holes in a printed circuit board for connection, as with a compliant pin or by soldering, to circuit traces on the board and/or in the holes. 
     Generally, locking means are provided between end walls  40  and  42  of each terminal  14  and connector housing  16  to lock the terminal in its respective terminal-receiving cavity  22 . More particularly, a locking finger  54  is stamped out of an opening  56  in each end wall  40  and  42  of the terminal. The locking fingers are bent outwardly from the end walls as best seen in FIG. 3, so that the locking fingers are angled outwardly and can be biased inwardly when the terminal is inserted into the housing. The locking fingers, therefore, are flexible and snap into engagement with locking ledges  30  (FIG. 1) formed on each end wall  28  of the respective terminal-receiving cavity  22 . Locking fingers  54  and locking ledges  30  thereby lock the terminal in its respective cavity. 
     Generally, abutment means are provided between each female terminal  14  and housing  16  within the respective cavity  22  to define the specific depth of insertion of the terminal into its cavity. More particularly, it can be seen that contact arms  50  do not span the entire width of side walls  38  of the terminals. This leaves a top abutment edge  58  of each end wall  40  and  42  to define an abutment shoulder. Therefore, when terminal  14  is inserted into its cavity  22  in housing  16 , abutment shoulders  58  at the top of end walls  40  and  42  of the terminal abuts against abutment shoulders  32  on end walls  28  of the cavity. 
     From the foregoing, it can be seen that both the locking means as well as the abutment means between female terminals  14  and connector housing  16  are provided at the end walls of the terminals and the end walls of the terminal-receiving cavities. Therefore, the cavities can be formed closer together lengthwise of the connector as viewed in FIG. 1 because extra plastic between the cavities is not needed to form the locking ledges. Instead, the locking ledges are at the ends of the cavities. In addition, coring does not have to be provided in relatively thin walls of the housing which define or separate the cavities as is prevalent in the prior art, where such means as locking or latching devices are provided in the side walls of the terminals. Also since the main current path is through the sidewall  38  between the contact arms  50  and the solder tails  52  and since the locking finger  54  is not punched from the side wall  38 , the current path through the side wall is substantially improved. Finally, because the abutment edge  58  of each side wall engages a respective abutment shoulder  32  and because locking finger  54  of each side wall engages a respective locking ledge  30  at opposite ends of the terminal, the terminal is held in the housing more securely than the two separate terminals ensuring a more consistent distance and, accordingly, a more consistent force between opposed contact points  50 a. Also, the larger two walled terminal is more easily inserted into the cavity as compared to the smaller singled walled terminal in the prior art. 
     It will be understood that the invention may be embodied in other specific forms without departing from the spirit or central characteristics thereof The present examples and embodiments, therefore, are to be considered in all respects as illustrative and not restrictive, and the invention is not to be limited to the details given herein.