Patent Publication Number: US-7713100-B2

Title: Male electrical terminal with a twisted contact section

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to a male electrical terminal which is elongated along a longitudinal axis, integrally made from a metal sheet, and which comprises
         a folded contact section which has a longitudinal junction line between two edges of the corresponding portion of the metal sheet, said contact section defining contact surfaces to be engaged by complementary contact surfaces of a complementary female terminal,   a securing section, suitable to be accommodated in a terminal accommodating chamber of an insulating housing, and to be engaged by a locking member of said housing so as to secure the terminal in said chamber, and   an intermediate section extending between said contact section and securing section.       

     Prior art terminals of this type are conventionally used in such an orientation in the connector housings that the contact surfaces are partially located on the junction line. In fact, the orientation of the terminal in the housing, and thus the location of the contact surfaces, is determined by the orientation of the securing section. 
     The contact surfaces provided by terminals of this type have discontinuities due to the junction lines, which are prejudicial to the conduction performances. 
     SUMMARY OF THE INVENTION 
     It is an object of the invention to solve this problem and provide a male electrical terminal with improved conduction performances, with no influence on the orientation of the securing section in the connector housing, and no need of modification of the latter. 
     Accordingly, the invention provides a male electrical terminal of the above-type, wherein the intermediate section is deformed in torsion around the longitudinal axis, whereby the junction line is angularly offset from the contact surfaces around the longitudinal axis. 
     The invention also relates to a process for manufacturing such a terminal, and to an electrical connector including such a terminal. 
     The invention will be better understood on reading the following description of one particular embodiment of the invention, given as a non-limiting example. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  and  FIG. 2  are perspective views, in two different directions, of a male terminal according to one embodiment of the invention; 
         FIG. 3  is a cross-sectional view, in a median longitudinal plane, of the male terminal of  FIGS. 1 and 2  in a mated position with a complementary female terminal; 
         FIG. 4  is a cross-sectional view of the male terminal in the plane  4 - 4  indicated on  FIG. 3 ; and 
         FIG. 5  is a similar view to  FIG. 1 , illustrating a former step of the manufacturing process of the male terminal shown on  FIG. 1-4 . 
     
    
    
     DETAILED DESCRIPTION OF ONE PREFERRED EMBODIMENT 
     A male electrical terminal according to the invention is shown on the  FIGS. 1-4 . 
     This male terminal  1  is of a type suitable to be crimped at one end of an electrical cable, and to be accommodated in the insulating housing (not shown) of a multi-way connector. 
     More specifically, this terminal is suitable for electrical connectors used in automotive applications. 
     The male terminal  1  is suitable to mate with a female terminal  3 , as shown on  FIGS. 3 and 4 . 
     The terminal  1  is elongated along a longitudinal axis X, which also represents the mating direction attached to the terminal  1 . The X-axis is oriented from the male terminal  1  towards the female terminal  3  in mating conditions. 
     The orientation or position terms used in the present description and related to the male terminal  1 , in particular the terms “forward” or “front”, refer to this mating axis X. 
     The terminal  1  is integrally made from a metal sheet (or blank), essentially by successive operations of stamping and folding. 
     The terminal  1  essentially has, extending successively in the longitudinal X-axis from the rear to the front, a crimping section  5 , a securing section  7 , and a contact section  9 . It also has an intermediate section  11  extending between the securing section  7  and the contact section  9 . 
     On  FIGS. 1 and 2 , the male terminal  1  is shown attached on a metal stripe  12  and integrally made therewith from the metal sheet. Of course, this stripe  12  is not part of the terminal, but is conventionally used to drive the blank through the tools during the manufacturing process and to attach together the series of terminals being processed. 
     The crimping section  5  is substantially U-shaped in cross-section (in a plane perpendicular to the X-axis), and substantially symmetrical with respect to an axial plane P, which will be supposed vertical in the following. 
     The above description of the crimping section  5 , and more generally any further description of the section  5 , is made for an initial state of the terminal, before crimping of the terminal on the wire. 
     In other embodiments, the crimping section could be replaced by any other suitable type of wire connecting section. 
     The securing section  7  is substantially box-shaped (parallelepipedic), with four longitudinally extending lateral walls, that is two opposed vertical walls  13  and two opposed horizontal walls  15 . 
     The securing section  7  is provided to be accommodated and secured in a chamber of the insulating housing of an electrical connector. To this purpose, the securing section  7  has a rear stop edge  17  provided to be engaged by a locking member, such as a flexible arm, of the connector housing. 
     The locking member is partially shown in section on  FIG. 3 , with the reference numeral  21 , in the engaged position with the stop edge  17 , whereby  FIG. 3  schematically illustrates the fully inserted and secured position of the male terminal  1  in the connector housing (represented by the locking arm  21 ). 
     It should be noted that, in an alternative embodiment (not shown), the securing section may have a recess or a window formed therein, provided to be engaged by a projecting tooth of a locking arm, in order to secure the terminal in the respective accommodating chamber. 
     In the example shown, the securing section  7  is also adapted to guide and orientate the terminal  1  upon its insertion in the housing. To this end, the securing section  7  has a guide and orientation member  23  outwardly projecting from one lateral wall  13 , and integrally formed therewith by stamping. 
     The contact section  9  is made as a pin, with an outer shape rectangular in cross-section. As more visible on  FIG. 4 , the pin  9  is further generally U-shaped in cross-section, considering the median line  25  of the metal sheet (dotted line on  FIG. 4 ), and symmetrical with respect to a horizontal longitudinal plane Q ( FIGS. 1 and 2 ). 
     The pin  9  is formed by folding the corresponding portion of the metal sheet along a longitudinal folding line, and applying both branches  27 A,  27 B of the U-shape one on the other. 
     One lateral face of the rectangular pin  9  is thus formed by the merging surfaces of the initially opposed edges  29 A,  29 B of the corresponding portion of the metal sheet, said surfaces  29 A,  29 B merging along a longitudinal junction line  30 . 
     The contact section  9  defines contact surfaces  33  ( FIGS. 3 and 4 ) engaged by complementary contact surfaces of the complementary female terminal  3 , in the mated position of said contacts, as shown on  FIGS. 3 and 4 . 
     As visible on  FIG. 1 , the intermediate section  11 , which connects the contact section  9  to the securing portion  7 , is twisted around the X-axis. In other words, the intermediate section is permanently deformed in torsion around the X-axis from its folded configuration, where it substantially has a plane symmetry, and where its symmetry plane is vertical and identical to P. 
     In these conditions, the symmetry plane Q of the pin  9  is angularly offset from the symmetry plane P of the crimping section, around the longitudinal X-axis, and more specifically orthogonal to this plane P. 
     Due to the permanent deformation of the intermediate section  11 , the junction line  30  is angularly offset around the X-axis from the contact surfaces  33 , which are provided on the external lateral surfaces of the branches  27 A,  27 B. 
     In the example shown, the offset angle is equal to 90°. 
     Referring to  FIGS. 3 and 4 , it will be noted that the female terminal  3  has a box-shaped body  41  with a lower longitudinal wall  43  and a rear edge  47 . The female terminal  3  also has a flexible contact blade  49  extending within the body  41 . 
     The wall  43  and the blade  49  define the contact surfaces of the female terminal, and are suitable to receive the pin  9  therebetween with a contact pressure on the contact surfaces  33 . 
     The terminal body  41  is accommodated in a chamber in a counterpart connector housing, and secured therein by means of a locking member  51  engaged with the rear edge  47 , which are similar in function respectively to the locking member  21  and the edge  17 . 
     In the configuration shown on  FIGS. 3 and 4 , the respective orientation of the terminals  1 ,  3  is such that the contact blade  49  and the lower wall  43  extend in a substantially horizontal manner, whereby the contact surfaces  33  extend horizontally on the external lateral faces of the branches  27 A,  27 B. 
     It will be appreciated that, in such a configuration, where one relative orientation of the terminals is imposed by the locking means  17 ,  21 ,  47 ,  51  of both terminals  1 ,  3 , the contact surfaces  33  are not intersected by the junction line  30 , since they are located on different faces of the pin  9 . 
     This is due to the torsional deformation of the intermediate section  11 , and provides improved continuous contact surfaces  33 . 
     With reference to  FIG. 5 , the process for manufacturing a male terminal as shown on  FIG. 1-4  will now be described. 
     In fact,  FIG. 5  shows the female terminal of the invention in a prior state in the manufacturing process, the terminal in this state being identified by the reference numeral  1 ′. 
     In first successive steps of the manufacturing process, the blank is stamped and folded so as to form the terminal  1 ′ in its non-twisted state, with the U-shaped crimping section  5 , the box-shaped securing section  7 , the U-shaped contact section  9 , and the intermediate section in a non-deformed state (non-deformed in torsion around the X-axis). The non-deformed intermediate section is indicated with the reference numeral  11 ′. 
     The first steps of the process leading to the terminal  1 ′ will not be further detailed since the terminal  1 ′ may be itself of a conventional type, and these first steps may also be conventional. 
     It should be noted on  FIG. 5 , that the terminal  1 ′ in its non-deformed state is generally symmetrical in outer shape with respect to the vertical axial plane P, and that the junction line  30  is then located in this symmetry plane P. 
     In a further step of the manufacturing process, the terminal  1 ′ is deformed in torsion at its intermediate section around the longitudinal X-axis, so as to turn the pin  9  of a 90° offset angle with respect to the securing section  7 . In this twisting (or torsion) step, the edges  29 A,  29 B are put in a vertical plane, that is parallel to the symmetry plane of the crimping section  5  and perpendicular to the stop edge  17  of the securing section  7 . 
     The symmetry plane Q of the contact section  9  is then perpendicular to the symmetry plane P of the crimping section  5 .