Patent Publication Number: US-11031733-B2

Title: Terminal fitting

Description:
BACKGROUND 
     Field of the Invention 
     The invention relates to a terminal fitting. 
     Related Art 
     Japanese Unexamined Patent Publication No. 2005-302573 discloses a female terminal fitting with a stabilizer preventing inverted insertion. The stabilizer of a female terminal fitting that is in a proper orientation will be inserted into an escaping groove in a cavity of a connector housing, thereby allowing the insertion of the terminal fitting. However, if the terminal fitting is in an inverted orientation by mistake, the stabilizer interferes with the connector housing to prohibit the insertion of the terminal fitting into the cavity. 
     However, a worker could attempt to insert a terminal fitting in an inverted and oblique posture, i.e. where the terminal fitting is in an inverted posture diagonally facing an entrance of the cavity. In this situation, a stabilizer, which is a most projecting part from the terminal fitting, is located substantially on a diagonal of a cavity. Thus, the stabilizer and the cavity interfere with each other to a small extent, and there has been a concern that the terminal fitting is inserted forcibly while pushing and widening an inner wall near the entrance of the cavity. 
     The invention was completed on the basis of the above situation and aims to provide a terminal fitting capable of effectively avoiding inverted insertion of a terminal fitting. 
     SUMMARY 
     The invention is directed to a terminal fitting with a rectangular tube and a stabilizer for preventing inverted insertion projecting on an outer surface of the rectangular tube. The terminal can be inserted into a cavity formed in a connector housing when the terminal fitting is facing the cavity in a proper posture. However, insertion of the terminal fitting is prohibited by the stabilizer interfering with the connector housing when the terminal fitting is facing the cavity in a posture inverted from the proper posture. An oblique insertion restricting portion is recessed on a corner of the rectangular tube while extending in a direction intersecting an inserting direction of the terminal fitting into the connector housing. The oblique insertion restricting portion is capable of restricting the insertion of the rectangular tube by a material of an inner wall of the cavity biting into the oblique insertion restricting portion when the terminal fitting is inserted into the cavity in an orientation inverted from the proper posture and in an oblique posture. 
     An attempt could be made to insert the terminal fitting forcibly into the cavity of the connector housing in a state where the terminal fitting is obliquely facing the cavity in an inverted posture. In this situation, corner parts of the conventional rectangular tube may forcibly push and widen the inner wall of the cavity to allow insertion. However, according to the present invention, even if the terminal fitting is inserted into the cavity in an inverted orientation and in an oblique posture, the material of the inner wall of the cavity bites into the oblique insertion restricting portion formed on the corner of the terminal fitting, thereby restricting improper insertion of the terminal fitting. 
     The oblique insertion restricting portion may be disposed on the corner located on at least one diagonal position of the rectangular tube. According to this configuration, when the terminal fitting is inserted in an inverted orientation into the cavity, the material of the cavity bites into the oblique insertion restricting portion located at the diagonal position to be caught, depending on a direction of inclination. Thus, improper insertion can be restricted more reliably. 
     The oblique insertion restricting portions may be disposed on corners on both widthwise sides in the rectangular tube. According to this configuration, improper insertion of the terminal fitting can be restricted regardless of whether the direction of inclination of the terminal fitting with respect to the cavity is a clockwise direction or a counterclockwise direction. 
     The oblique insertion restricting portion may include a resilient piece cantilevered in a direction intersecting the inserting direction of the terminal fitting and may be deflectable inward of the rectangular tube by forming a substantially U-shaped slit penetrating through a wall of the rectangular tube. According to this configuration, when the terminal fitting is inserted in an inverted orientation into the cavity, the material of the inner wall of the cavity pushes the resilient piece inward of the rectangular tube. This enables the material of the inner wall of the cavity to bite into the oblique insertion restricting portion in a wider range, as compared to the case where a slit is merely provided in the rectangular tube by recessing. Therefore, improper insertion can be restricted more reliably. 
     The oblique insertion restricting portion may include a plurality of the resilient pieces along the inserting direction, and extending directions of the resilient pieces adjacent in the inserting direction may be mutually opposite directions. According to this configuration, even if an angle of inclination of the terminal fitting at the time of inverted insertion varies, the resilient pieces are deflected in a wider range by the material of the inner wall of the cavity since adjacent resilient pieces of the oblique insertion restricting portion extend in opposite directions. Thus, even if the angle of inclination of the terminal fitting at the time of inverted insertion varies, improper insertion can be restricted reliably. 
     An outer surface of the oblique insertion restricting portion and an outer surface of the rectangular tube around the oblique insertion restricting portion may be substantially flush with each other. According to this configuration, the oblique insertion restricting portion is substantially flush with the outer surface of the rectangular tube. Thus, insertion resistance when the terminal fitting is inserted properly need not be increased. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view of a terminal fitting according to a first embodiment. 
         FIG. 2  is a plan view of the terminal fitting. 
         FIG. 3  is a side view of the terminal fitting. 
         FIG. 4  is a front view of the terminal fitting. 
         FIG. 5  is a section along A-A of  FIG. 3 . 
         FIG. 6  is a front view in section of a connector showing a state where the terminal fitting is accommodated in a proper orientation in a cavity. 
         FIG. 7  is a section enlargedly showing a state where the terminal fitting is accommodated in the proper orientation in the cavity. 
         FIG. 8  is a section enlargedly showing a state where the terminal fitting is obliquely inserted in an inverted orientation into the cavity. 
         FIG. 9  is a perspective view of a terminal fitting according to a second embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     First and second embodiments of a terminal fitting of the invention are described below with reference to the drawings. 
     First Embodiment 
     (Connector Housing  1 ) 
       FIGS. 1 to 8  show the first embodiment of the invention. First, a connector housing  1  for accommodating terminal fittings T according to the first embodiment is described. As shown in  FIG. 6 , the connector housing  1  is composed of a terminal accommodating portion  2  for accommodating the terminal fittings T and a receptacle  3  surrounding the terminal accommodating portion  2 . Cavities  4  for accommodating the terminal fittings T are provided in upper and lower stages in the terminal accommodating portion  2 . 
     Each terminal fitting T is inserted into each cavity  4  from behind. As shown in  FIGS. 7 and 8 , each cavity  4  has a substantially rectangular cross-section long in a vertical direction and short in a width direction. 
     Each cavity  4  has a guide groove  5  recessed substantially over the entire length from an entrance of the cavity  4  and allows the insertion of stabilizers  23 ,  26  to be described later while guiding the stabilizers  23 ,  26  when the terminal fitting T is facing the cavity  4  in a proper orientation. However, if the terminal fitting T is facing the cavity  4  in a vertically inverted orientation, the stabilizers  23 ,  26  interfere with a wall surface around the entrance of the cavity  4 , thereby prohibiting inverted insertion. The guide groove  5  is located in a widthwise central part on the ceiling surface of the cavity  4 . 
     (Terminal Fitting T) 
     Next, the terminal fitting T is described. In the following description, a “front-rear direction” is based on that shown in  FIG. 2  and a “vertical direction” and a “lateral direction” are based on those shown in  FIG. 4 . 
     The terminal fitting T according to the first embodiment is a female terminal fitting T formed of a thin plate material made of conductive metal. As shown in  FIG. 1 , the terminal fitting T includes a terminal connecting portion  6  for connection to a mating male terminal fitting on a front end and a wire connecting portion  7  to be connected to an end part of a wire W on a rear end. The wire connecting portion  7  is composed of a wire barrel  8  to be crimped to a core exposed at an end of the wire and an insulation barrel  9  to be crimped to a coating of the wire. 
     The terminal connecting portion  6  includes a rectangular tube  10  that is open in the front-rear direction. A front opening serves as a tab insertion opening  11  through which a tab of the mating terminal fitting is inserted. The rectangular tube  10  has a substantially rectangular shape long in the vertical direction and can be fit and inserted into the cavity  4 . 
     As shown in  FIGS. 4 and 5 , the rectangular tube  10  includes a bottom wall  12  continuous from a bottom surface of the wire connecting portion  7 , and two side walls  13 R,  13 L rising from both lateral sides of the bottom wall  12 . 
     A resilient tongue  14  is folded back into the rectangular tube  10  from a front part of the bottom wall  12 . The resilient tongue  14  can be deflected in the vertical direction, and a movable contact point  15  is formed on a top part to project up by being struck from below. 
     A ceiling wall  16  extends from a rising end of the right side wall  13 R toward the left side wall  13 L. Front and rear windows  17 F,  17 R are open in a corner part from the rising end of the right side wall  13 R to the ceiling wall  16 . Further, as shown in  FIG. 2 , a laterally central part of the ceiling wall  16  is recessed inward of the rectangular tube  10  into a groove extending along the front-rear direction. Thus a fixed contact point  18  facing the resilient tongue  14  projects inside the rectangular tube  10 . In connecting the male and female terminal fittings, the tab of the male terminal fitting is sandwiched resiliently by the movable contact point  15  and the fixed contact point  18  to establish electrical conduction. 
     A front covering wall  19  and a rear covering wall  20  divided in the front-rear direction respectively extend horizontally from a rising end of the left side wall  13 L toward the right side wall  13 R. A front hanging piece  21  is bent down from the front end of the front covering wall  19 , and the front surface thereof is a curved surface. 
     A front widened portion  22  is cantilevered behind a cut formed in the lateral direction in a rear part of the front covering wall  19 . A lance locking portion  23  doubling as a stabilizer for preventing inverted insertion of the terminal fitting T projects up in a laterally central part of the front widened portion  22 . The lance locking portion  23  is lockable to an unillustrated locking lance deflectably formed in each cavity  4 . The lance locking portion  23  is curved and formed to be substantially U-shaped in a front view. The lance locking portion  23  is disposed in a central part with respect to a lateral direction of the rectangular tube  10 . Both front and rear end surfaces of the lance locking portion  23  are vertically upright. 
     Further, a front displacement preventing piece  24  is formed on a free end side of the front widened portion  22 . This front displacement preventing piece  24  is fit into the front window  17 F, so the front and rear end surfaces thereof face front and rear opening edges of the front window  17 F with almost no clearance therebetween. 
     On the other hand, a rear displacement preventing piece  25  is formed on a free end of the rear covering wall  20  before a cut formed in the lateral direction. The rear displacement preventing piece  25  is fit into the rear window  17 R, so the front and rear end surfaces thereof face front and rear opening edges of the rear window portion  17 R with almost no clearance defined therebetween. In this way, the front and rear covering walls  19 ,  20  are positioned in the front-rear direction by the front and rear displacement preventing pieces  24 ,  25  to maintain the box shape of the rectangular tube  10 . 
     A retainer locking portion  26  doubling as a stabilizer projects up in a laterally central part behind the cut in the rear covering wall  20 . Similar to the lance locking portion  23 , the retainer locking portion  26  also is substantially U-shaped in a front view. The retainer locking portion  26  is locked by a retainer (not shown) mounted into the connector housing  1  and doubly locks the terminal fitting T together with the locking lance. The retainer locking portion  26  also is disposed in a central part with respect to the lateral direction of the rectangular tube  10 . 
     The retainer locking portion  26  and the lance locking portion  23  are disposed on the same axis in the front-rear direction and are displaceable along the guide groove  5  provided in the cavity  4 . 
     Oblique insertion restricting portions  27 ,  28  are disposed on four corners of the rectangular tube  10  for impeding insertion of the terminal fitting T in an inverted orientation and an oblique posture into the cavity  4   10 . In the first embodiment, two front oblique insertion restricting portions  27  and two rear oblique insertion restricting portions  28  are disposed at two front and rear positions. The oblique insertion restricting portions  27  are disposed on a front end and on corners from both lateral side parts of the bottom wall  12  to base end parts of both side walls  13 R,  13 L and are located substantially right below the front displacement preventing piece  24 . 
     Each of the front oblique insertion restricting portions  27  includes front and rear resilient pieces  27 A 1 ,  27 A 2 . The front and rear resilient pieces  27 A 1 ,  27 A 2  in each front oblique insertion restricting portion  27  are formed inward of substantially U-shaped slits  29  penetrating through the wall of the rectangular tube  10 . At this time, the slits  29  are formed in the lateral direction for perpendicularly intersecting an inserting direction of the terminal fitting T into the cavity  4  and extending directions of substantially U-shaped parts are mutually opposite directions. By cutting the slits  29  in the directions opposite to each other in this way, the front resilient piece  27 A 1  has a cantilever shape so that the side of the side wall  13 R,  13 L is a connected base end and the side of the bottom wall  12  is a free end. Conversely, the rear resilient piece  27 A 2  has a cantilever shape so that the side of the side wall  13 R,  13 L is a connected base end and the side of the bottom wall  12  is a free end. Thus, both resilient pieces  27 A 1 ,  27 A 2  extend in the lateral direction of the rectangular tube  10 , i.e. in the direction perpendicularly intersecting the inserting direction of the terminal fitting T and are deflectable inward and outward of the rectangular tube  10 . 
     Further, a partition wall  30  having both end parts respectively connected to the bottom wall  12  and the side wall  13 L,  13 R is formed between the resilient pieces  27 A 1 ,  27 A 2  while being supported on both ends. Outer surfaces of the partition wall  30  and the resilient pieces  27 A 1 ,  27 A 2  are substantially flush with a peripheral surface of the oblique insertion restricting portion  27 . 
     Note that, as shown in  FIG. 3 , the front end of the resilient piece  27 A 1  located on the front side in the front oblique insertion restricting portion  27  is located slightly before the front end surface of the lance locking portion  23 . 
     The oblique insertion restricting portions disposed on a rear side (rear oblique insertion restricting portions  28 ) are disposed on corner parts of an upper surface of the rectangular tube  10  substantially in a center between the front and rear covering walls  19  and  20 . Left and right rear oblique insertion restricting portions  28  are formed over ranges from an upper surface side of the ceiling wall  16  of the rectangular tube  10  to side surfaces, and are located substantially on diagonals of the rectangular tube  10  with respect to the front oblique insertion restricting portions  27 . Similar to the front oblique insertion restricting portions  27 , each rear oblique insertion restricting portion  28  also includes two resilient pieces  28 A 1 ,  28 A 2 . The configuration of the rear oblique insertion restricting portions  28  is completely similar to that of the front oblique insertion restricting portions  27 , including a feature that extending directions of the resilient pieces  28 A 1 ,  28 A 2  toward free end sides in each rear oblique insertion restricting portion  28  are opposite to each other. 
     In this way, both the front and rear oblique insertion restricting portions  27 ,  28  interfere with the inner wall of the cavity  4 , as shown in  FIG. 8 , if it is attempted to insert the terminal fitting T in an inverted posture and in an oblique posture into the cavity  4 . 
     Next, functions and effects of the first embodiment configured as described above are described. When the terminal fitting T is facing the cavity  4  in a proper posture, the lance locking portion  23  and the retainer locking portion  26 , which are front and rear stabilizers, are fit into the guide groove  5  of the cavity  4 . Thus, the terminal fitting T is inserted into the cavity  4  by these locking portions  23 ,  26  being guided by the guide groove  5 . At this time, since the outer surfaces of any of the resilient pieces  27 A 1 ,  27 A 2 ,  28 A 1  and  28 A 2  and the partition wall  30  are flush with the peripheral surface of the rectangular tube  10  in the terminal fitting T of the first embodiment, the respective oblique insertion restricting portions  27 ,  28  do not become resistance at the time of insertion. Thus, the terminal fitting T can be inserted smoothly into the cavity  4 . 
     On the other hand, if the terminal fitting T is facing the cavity  4  in a posture vertically inverted by 180° from the proper posture, a front end part of the rectangular tube  10  partially enters the cavity  4 , but a projecting part of the lance locking portion  23  interferes with an entrance part of the cavity  4 . As described above, since the front end surface of the lance locking portion  23  is a vertical upright surface, this front end surface is in surface contact with a wall surface of the entrance part of the cavity  4 . Thus, a situation where the terminal fitting T is inserted in the inverted posture can be prohibited reliably. 
     However, if the terminal fitting T is inclined counterclockwise, as shown in  FIG. 8 , while the front end part of the rectangular tube  10  is inserted shallowly into the cavity  4  in a straight inverted posture, the lance locking portion  23  is located substantially on the diagonal of the cavity  4 . Therefore an interference margin of the lance locking portion  23  with the entrance part of the cavity  4  becomes small. Thus, if the terminal fitting T is pushed forcibly, the front oblique insertion restricting portion  27  located on a corner part (upper-left corner part in  FIG. 8 ) of the front part of the rectangular tube  10  already shallowly inserted into the cavity on a side opposite to the lance locking portion  23  is pressed strongly against the inner wall of the cavity  4 . As a result, the inner wall having received a pressing force applies a pressure contact force to the front oblique insertion restricting portion  27  by the reaction thereof. In this way, a material M of the inner wall of the cavity  4  deflects and deforms the resilient pieces  27 A 1 ,  27 A 2  inward, causing the material M to bite into the front oblique insertion restricting portion  27 . If it is attempted to push the terminal fitting T farther in this state, the material having bitten into the front oblique insertion restricting portion  27  is caught to generate large insertion resistance. In this way, a situation where the terminal fitting T is inserted in an improper posture into the cavity  4  is avoided. 
     The left and right front oblique insertion restricting portions  27  are provided in the first embodiment. Thus, the terminal fitting T can also deal with the case where the terminal fitting T is inclined in a direction opposite to that shown in  FIG. 8 . Further, insertion can be restricted more reliably since the front oblique insertion restricting portion  27  includes the resilient pieces  27 A 1 ,  27 A 2 , and more material can be caused to bite into the front oblique insertion restricting portion  27 , as compared to the case where a slit is merely provided. Furthermore, the rear oblique insertion restricting portions  28  also are provided in this embodiment. Thus, insertion can be restricted at the diagonal positions of the terminal fitting T. This is also effective in restricting oblique insertion of the terminal fitting T in an inverted orientation. 
     The outer surfaces of the resilient pieces  27 A 1 ,  27 A 2 ,  28 A 1  and  28 A 2  and the partition wall  30  do not project from the peripheral surfaces in the oblique insertion restricting portions  27 ,  28 . Thus, it is also possible to obtain an effect that insertion resistance need not be increased at all during a normal inserting operation. Furthermore, since the resilient pieces extend in the opposite directions in each oblique insertion restricting portion  27 ,  28 , a wide inclination range of the terminal fitting T where either one of the front and rear resilient pieces  27 A 1 ,  27 A 2 ;  28 A 1 ,  28 A 2  can be sufficiently deflected can be ensured. That is, a range capable of dealing with oblique insertion can be expanded. 
     Second Embodiment 
       FIG. 9  shows the second embodiment of the invention. Although the resilient pieces  27 A 1 ,  27 A 2 ,  28 A 1  and  28 A 2  are curved in conformity with curved shapes of the corner parts of the rectangular tube  10  in the first embodiment, resilient pieces extend straight in vertical and lateral directions from a wall surface constituting a rectangular tube  10  in oblique insertion restricting portions  31 ,  32  in the second embodiment. As in the first embodiment, the periphery of each resilient piece  31 A 1 ,  31 A 2 ,  32 A 1 ,  32 A 2  is a cantilever by forming a slit  29 , and is deflectable and deformable, although only to a slight extent. Further, unlike the first embodiment, the resilient pieces  31 A 1 ,  31 A 2 ,  32 A 1  and  32 A are formed such that tip sides partially project from the periphery of the rectangular tube  10 . 
     The other configuration is similar to the first embodiment. Hence, similar functions and effects can be achieved. 
     The invention is not limited to the above described and illustrated embodiments. For example, the following embodiments also are included in the scope of the invention. 
     Although the oblique insertion restricting portion is provided with the resilient pieces in the above embodiments, the oblique insertion restricting portion may be provided with a slit merely extending in the lateral direction. 
     Although the oblique insertion restricting portion is formed by forming the substantially U-shaped slits in the above embodiments, a recessed groove such as a knurled groove may be formed in the corner part of the rectangular tube portion  10 . In short, it is sufficient to form convex and concave parts intersecting the inserting direction of the terminal fitting T. 
     Although the invention is applied to the female terminal fitting T in the above embodiments, application to male terminal fittings is also possible. 
     Although the lance locking  23  and the retainer locking portion  26  project while having a substantially U shape in the above embodiments, the lance locking portions  23  and the retainer locking portion  26  may have other shapes. For example, the rectangular tube  10  may be provided with a locking hole to be locked by the locking lance or the retainer may be locked to the rear end surface of the rectangular tube  10  instead of the retainer locking portion  26 . 
     LIST OF REFERENCE SIGNS 
     
         
           1  . . . connector housing 
           4  . . . cavity 
           10  . . . rectangular tube 
           23  . . . lance locking portion (stabilizer) 
           26  . . . retainer locking portion (stabilizer) 
           27 ,  31  . . . front oblique insertion restricting portion 
           28 ,  32  . . . rear oblique insertion restricting portion 
         T . . . terminal fitting 
           27 A 1 ,  27 A 2 ,  31 A 1 ,  31 A 2  . . . resilient piece in front oblique insertion restricting portion 
           28 A 1 ,  28 A 2 ,  32 A 1 ,  32 A 2  . . . resilient piece in rear oblique insertion restricting portion