Patent Publication Number: US-6659814-B2

Title: Male terminal fitting and method of manufacture

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a male tab, to a male terminal fitting provided therewith and to a method of forming it. 
     2. Description of the Related Art 
     A known male terminal fitting is identified by the numeral  100  in FIGS. 8 and 9, and also is disclosed in Japanese Unexamined Patent Publication No. 4-39880. The male terminal fitting  100  is formed by bending an electrically conductive plate to define a male tab  101  with a front end that is connectable with an unillustrated mating female terminal fitting. The male tab  101 , as shown in FIG. 9, achieves a specified thickness T by providing a bottom wall  102  and bending opposite sidewalls  103  on the upper surface of a leading end of the bottom wall  102 . 
     Connectors for automotive vehicles and the like have been made smaller in recent years to accommodate a demand for miniaturization of connectors. Small terminal fittings for such miniaturized connectors also have been developed. However, miniaturized male terminal fittings may experience some problems that may not be experienced by the conventional male terminal fitting  100 . For example, the electrically conductive plate is too thin to achieve the specified thickness for the male tab  101  by the conventional forming method. 
     FIGS. 10 to  12  show a male terminal fitting  110  with a male tab  111  that may be considered to address the above-described problem. The male terminal fitting  110  is formed by bending the electrically conductive plate  114  of FIG. 10 to define a male tab  111  with a specified space S between the upper and lower sides and with a specified thickness T, as shown in FIG.  12 . However, the male tab  111  must be press formed by upper and lower molds  115 ,  116 , as shown in FIG.  13 . This press forming causes the ends  112  of the plate to move closer to each other from the bends  113  and to incline inwardly along the thickness direction. As a result, the male tab  111  is not flat and has a small contact area with the female terminal fitting. 
     The present invention was developed in view of the above problem and an object thereof is to provide a male terminal fitting with a male tab having a specified thickness and flatly formed even in the case of using a thinner electrical conductive plate member. 
     SUMMARY OF THE INVENTION 
     The invention is directed to a male tab formed by folding an electrically conductive plate to place a first panel of the plate substantially over a second panel thereof. A supporting panel extends from the first and second panels of the electrically conductive plate and is folded and held tightly between the first and second panels. Thus, the supporting panel is between the first and second panels and supports the first and second panels at a distance from each other. 
     The male tab can be at one end of a male terminal fitting, but also can be used for other parts, such as terminal fittings with male and female connecting portions or coupling terminals with plural male tabs. In the latter terminal, the inventive male tabs may be used for all or part of the male tabs. 
     As explained above, a supporting panel extends from at least one of the facing sides of the first and second panels of the electrically conductive plate is folded and held tightly between the facing sides to prevent the facing sides from being inclined inwardly along the thickness direction during pressing. Thus, the male tab has a flatter surface. Further, the thickness of the male tab can be enlarged as much as the thickness of the tightly held end. Accordingly, a specified thickness can be ensured even in the case of using a thinner electrically conductive plate. 
     The support panel held tightly between the first and second panels of the electrically conductive plate may be thinner than other parts of the electrically conductive plate to be formed into the male tab. Accordingly, the tightly held supporting panel can be folded easily. Further, the thinner supporting panel makes it more difficult to form a space at a bent portion when being folded. Therefore, dimensional errors along the thickness direction of the male tab can be reduced. 
     A connecting panel between the first and second panels with a specified dimension preferably is arranged at an angle to the first and second panels. The first and second panels may be maintained in their positional relationship by the at least one facing end and by the connecting panel. 
     Most preferably, the first and second panels are substantially parallel. 
     The invention also relates to a male terminal fitting, such as a terminal fitting with a pair of male and female connecting portions or a coupling terminal. The terminal fitting may comprise a wire-connecting portion to be connected to a wire. A male tab as described above is connected electrically with the wire-connecting portion. The tab and the wire-connecting portion may be unitary with one another. 
     The invention also relates to a method of forming a male tab. The method comprises folding an electrically conductive plate so that first and second panels are placed substantially one over the other and so that a supporting panel is folded at least on one of the first and second panels and held between the first and second panels. Thus, the first and second panels are placed one over the other while being supported by the supporting panel that is sandwiched between the first and second panels. 
     The electrically conductive plate preferably is pressed such that the supporting panel has a thickness that is smaller than that of the other parts of the electrically conductive plate. 
     The electrically conductive plate preferably is folded so that the connecting panel between the first and second panels has a specified dimension and is arranged at an angle to the first and second panels. 
     The electrically conductive plate preferably is folded so that the first and second panels are maintained in their positional relationship by the at least one facing end portion and by the connecting panel. 
     These and other objects, features and advantages of the present invention will become more apparent upon reading of the following detailed description of preferred embodiments and accompanying drawings. It should be understood that even though embodiments are separately described, single features thereof may be combined to additional embodiments. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a male terminal fitting provided with a male tab according to one embodiment of the present invention. 
     FIG. 2 is a development of the male terminal fitting. 
     FIG. 3 is a sectional view along  3 — 3  of FIG.  2 . 
     FIG. 4 is a side view of the male terminal fitting. 
     FIG. 5 is a top view of the male terminal fitting. 
     FIG. 6 is a sectional view along  6 — 6  of FIG.  4 . 
     FIG. 7 is a sectional view showing the male tab being formed. 
     FIG. 8 is a perspective view of a prior art male terminal fitting. 
     FIG. 9 is a sectional view along  9 — 9  of FIG.  8 . 
     FIG. 10 is a development of the male terminal fitting designed to provide a male tab having a specified thickness when an electrically conductive plate member is thin. 
     FIG. 11 is a side view of the male terminal fitting when the electrically conductive plate of FIG. 10 is folded. 
     FIG. 12 is a sectional view along  12 — 12  of FIG.  11 . 
     FIG. 13 is a sectional view showing a state where the male tab shown in FIG. 12 is formed by pressing. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A male terminal fitting according to the invention is identified by the numeral  1  in FIG. 1, and is formed by cutting, stamping, bending, folding and/or embossing an electrically conductive plate  4 , as shown in FIG.  2 . The male terminal fitting  1  has opposite front and rear ends. A wire-connecting portion  2  is formed at the rear end of the male terminal fitting  1  and is configured for connection with an end of a wire. A male tab  3  is formed at the front end of the male terminal fitting  1  and is configured for connection with an unillustrated mating female terminal fitting. The male tab  3  is produced especially in consideration of miniaturization, and one side of the front cross section of the male tab  3  is about 0.6 mm to 2 mm. A rectangular tubular support  6  is provided behind the male tab  3 . 
     The electrically conductive plate  4  is bent or folded to form the male tab  3 . Specifically, as shown in FIG. 2, a portion of the electric conductive plate  4  to become the male tab  3  of the male terminal fitting  1  is provided with a first panel  3 A, a second panel  3 B and a connecting panel  3 C between the first and second panel  3 A and  3 B for enabling the male tab  3  to have a specified thickness T. A foldable supporting panel  3 D extends along a longitudinal side of the second panel  3 B substantially opposite to the first panel  3 A. The foldable supporting panel  3 D is pressed at a specified pressure before bending to reduce the thickness of the foldable supporting panel  3 D and to define a step  5  adjacent the second panel  3 B. The foldable supporting panel  3 D has a thickness X, as shown in FIG. 3, that is less than a thickness Y at other locations on the male tab  3 , including the first panel  3 A, the second panel  3 B and the connecting panel  3 C (i.e. X&lt;Y). 
     Trapezoidal insertion ends  7 A,  7 B are formed at the front ends of the first and second panels  3 A,  3 B of the male tab  3 . The insertion ends  7 A,  7 B are bent substantially into contact with each other substantially at a middle position along the thickness direction TD of the male tab  3  to form an insertion end  7 . The insertion end  7  may be thinned along the longitudinal direction of the male tab  3  towards its leading end. 
     Although not shown, a ribbon-shaped strip is provided at the left side of FIG. 2, and a plurality of electrically conductive plates  4  are connected with the strip via connecting pieces  4 A at specified intervals in a direction substantially normal to the extending direction of the strip. The male terminal fittings  1  are formed by cutting, stamping, bending, folding and/or embossing while the connected plates pass through an unillustrated pressing apparatus in this state. 
     As shown in FIG. 2, the electrically conductive plates  4  are subjected to specified pressing while passing through the pressing apparatus, and thereby are formed successively into male terminal fittings  1 . In this process, the foldable supporting panel  3 D is folded along the step  5  in the direction of the arrow R in FIG. 3 to such a degree as to be held in close contact with the rear portion  3 B. The foldable supporting panel  3 D is folded substantially completely onto the second panel  3 B and contacts the second panel  3 B over substantially the entire area. However, it is possible that the foldable supporting panel  3 D is folded onto the second panel  3 B with a bending radius to leave a space between part of the foldable supporting panel  3 D and the second panel  3 B. Further, boundaries between the opposite sides of the connecting panel  3 C and the first and second panels  3 A and  3 B are bent substantially at right angles. Thus, the front sectional view of the male tab  3  is substantially square or rectangular (see e.g. FIG.  6 ). 
     The male tab  3  is pressed by upper and lower molds  8 ,  9 , as shown in FIG.  7 . Further, the foldable supporting panel  3 D is held tightly or squeezed between the ends of the first and second panels  3 A,  3 B. 
     As described above, the foldable supporting panel  3 D is held tightly between the ends of the first and second panels  3 A,  3 B of the electrical conductive plate  4 . Thus, the first and second panels  3 A and  3 B are prevented from inclining inward along thickness direction TD during the pressing, and the male tab  3  has flatter surfaces. Further, the thickness of the male tab  3  can be enlarged as much as the thickness X of the foldable supporting panel  3 D. Thus, the male tab  3  can have the specified thickness T even if the electrically conductive plate member  4  is thin. 
     The thickness X of the foldable supporting panel  3 D is less than the thickness Y of the other parts of the electrical conductive plate  4  for the male tab  3 . Thus, the foldable supporting panel  3 D can be folded easily. Furthermore, the thickness X of the foldable supporting panel  3 D thinner than the other parts makes it more difficult to form a space at a connecting portion  10  between the second panel  3 B and the foldable supporting panel  3 D at the underside of the step  5  when the foldable supporting panel  3 D is folded. Therefore, dimensional errors along the thickness direction of the male tab  3  can be reduced. 
     Further, even if the male tab  3  is connected with the female terminal fitting for a long time, the foldable supporting panel  3 D prevents the inward inclination along the thickness direction TD of the male tab  3 , see FIG. 13 of the first and second panels  3 A,  3 B, thereby keeping good contact. 
     Accordingly, the method for forming a male tab comprises pressing a conductive plate  4  to form a supporting panel  3 D having a specified thickness X that is less than the thickness Y of the conductive plate  4 . The method continues by folding the supporting panel onto the first and/or second panel  3 A,  3 B. The method then includes bending the conductive plate  4  such that the first and second panels  3 A,  3 B are substantially parallel and substantially face each other with the supporting panel  3 D sandwiched therebetween. Thus, the supporting panel  3 D is folded onto the second panel  3 B and contacts the first panel  3 A for holding the first and second panels  3 A and  3 B at a distance and supported on each other. Accordingly, the first panel  3 A substantially contacts and is near the supporting panel  3 D and is substantially in contact with and near the second panel  3 B along the thickness direction TD.