Abstract:
A base wall ( 21 ) of a connector housing ( 20 ) is formed with through holes ( 25 ), into which terminal fittings ( 60 ) are insertable. The inner surface of each through hole ( 25 ) includes an inclined portion ( 26 ) narrowed toward the rear side from the front surface of the base wall ( 21 ) and arranged at a position corresponding to projections ( 71 ) for guiding the terminal fitting ( 60 ), a straight portion ( 28 ) located behind the inclined portion ( 26 ), extending in an inserting direction toward the rear surface of the base wall ( 21 ) and having a press-in area for press-in portions ( 67 ), and restricting portions ( 27 ) defining steps together with the straight portion ( 28 ), extending from a taper end of the inclined portion ( 26 ) to the steps ( 35 ) and tightly holding rear parts of the projections ( 71 ) while preventing loose movements.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The invention relates to a connector. 
   2. Description of the Related Art 
   Japanese Unexamined Patent Publication No. 2006-19228 relates to a circuit board connector with a housing. Through holes penetrate a base wall of the housing in a thickness direction and long narrow terminal fittings are inserted through the base wall. Each terminal fitting includes a press-in portion to be pressed into the through hole and a projection that projects out in width direction behind the press-in portion for limiting the penetration of the terminal fitting. Press-in areas are formed in middle parts of the through holes in forward and backward directions and receive the press-in portions of the terminal fittings. Recesses are formed in rear parts of the through holes. Front ends of the recesses and the rear ends of the press-in areas are connected via steps. Further, each recess has an inclined portion narrowed in an inserting direction of the terminal fitting from the rear end of the base wall for guiding the insertion of the terminal fitting. 
   The projections fit loosely in the recesses due to the presence of the inclined portions. Thus, a force for holding the terminal fitting in the base wall depends on the size of pressing margins of the press-in portions engageable with the press-in areas of the through holes. However, if the pressing margins are large, the insertion resistance of the terminal fittings increases to worsen operability. If the pressing margins are small, the terminal fittings are likely to misalign. 
   The invention was developed in view of the above situation and an object thereof is to reduce insertion forces for a terminal fitting and adjusting the alignment of the terminal fitting. 
   SUMMARY OF THE INVENTION 
   The invention relates a connector with a housing with a base wall and through holes that penetrate the base wall in a thickness direction. Terminal fittings are insertable into the through holes. Each terminal fitting is long and narrow, and has at least one projection projecting out in a width direction. At least one press-in portion is located before the projection with respect to an inserting direction and is pressed into a space defined by the inner surface of the through hole. At least one inclination is formed on the inner surface of each through hole and is narrowed towards the front with respect to the inserting direction of the terminal fitting from one end surface of the base wall. The inclination is at a position corresponding to the projection for guiding the terminal fitting. At least one substantially straight portion is located before the inclination with respect to the inserting direction of the terminal fitting and extends in the inserting direction towards the other end surface of the base wall. The straight portion has at least one press-in area for the press-in portion. At least one restriction defines at least one step together with the substantially straight portion and extends from a taper end of the inclined portion to the step for tightly holding a front area of the projection with respect to the inserting direction while preventing loose movements of the projecting portion. 
   Front areas of the projections with respect to the inserting direction are held tightly by the restrictions of the through holes while having loose movements thereof prevented. Thus, the terminal fittings are positioned and aligned. Accordingly, the press-in portions do not require large press-in margins engageable with the press-in areas for alignment adjustment and inserting forces for the terminal fittings can be reduced. 
   Each restriction preferably tightly holds the front area of the corresponding projection with respect to the inserting direction in a pressed state. Thus, an external force is unlikely to shake the terminal fitting. 
   The substantially straight portion of each through hole preferably includes at least one recess that does not contact a plate surface of the facing terminal fitting. Thus, the inserting force for the terminal fitting is reduced even further, and abrasion related damage on the plate surface of the terminal fitting is prevented. 
   The terminal fitting preferably is aligned by the restriction. 
   A main portion of the terminal fitting preferably passes the straight portion of the through hole without contact during insertion of the terminal fitting. 
   The restriction preferably positions the projection of the terminal fitting substantially towards the center of the through hole, and preferably is formed by three mutually orthogonal surfaces for restraining the widthwise outer end of the projection in a thickness direction. 
   The projections preferably are substantially rectangular and are arranged at opposite lateral edges of the main portion. The projections preferably project farther from the lateral edges of the main portion than the press-in portions. 
   Two press-in portions preferably are spaced apart in the inserting direction. 
   A preceding press-in portion in the inserting direction preferably has a shorter projecting distance than a succeeding press-in portion. 
   A slanted edge of the preceding press-in portion preferably is connected to a tip via a curve or non-linear portion and a slanted edge of the succeeding press-in portion preferably is connected to a tip via an angle. 
   The press-in portion preferably contacts a lateral surface of the through hole in such a manner to bite therein. 
   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 side view of terminal fittings in a housing of a first embodiment. 
       FIG. 2  is a partial enlarged plan view of the terminal fitting before being inserted into a through hole of a base wall. 
       FIG. 3  is a partial enlarged plan view of the terminal fitting inserted into the through hole of the base wall. 
       FIG. 4  is a partial enlarged front view of the terminal fitting inserted into the through hole of the base wall. 
       FIG. 5  is a front view of the housing before the terminal fittings are mounted. 
       FIG. 6  is a partial enlarged front view of another terminal fitting inserted into a through hole of the base wall. 
       FIG. 7  is a partial enlarged front view of a terminal fitting inserted into a through hole of a base wall in a second embodiment. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   A connector according to a first embodiment of the invention is described with reference to  FIGS. 1 to 6 . The connector has a housing  20  and terminal fittings  60 , and is connectable with a mating connector (not shown) while being mounted on a circuit board  90 . In the following description, and end that is to be connected with the mating connector is referred to as the front end. 
   Each terminal fitting  60  is formed unitarily by press-working an electrically conductive (preferably metal) plate and has a long, narrow, flat rectangular tab. As shown in  FIG. 1 , a terminal connecting portion  61  is defined at one end of the terminal fitting  60  and is configured to be connected with a mating terminal fitting. A board connecting portion  62  is formed at the opposite end of the terminal fitting  60  and is to be passed through a through hole of the circuit board  90 . The leading ends of the terminal connecting portion  61  and the board connecting portion  62  are tapered for guiding purposes. This connector  10  includes small and large terminal fittings  60  with different plate widths. 
   The terminal fitting  60  is press fit into a base wall  21  of the housing  20  from the front and, after the insertion, the board connecting portion  62  projecting back from the rear of the housing  20  is bent at a substantially right angle towards the circuit board  90  to form an L-shaped bend  63 . As shown in  FIG. 2 , the terminal fitting  60  has a longitudinally extending main portion  64  between the bend  63  and the terminal connecting portion  61 . The main portion  64  has the same width as the bend  63  and the terminal connecting portion  61  and is accommodated in the base wall  21  so that the thickness of the main portion  64  aligns with height of the housing  20 . 
   Press-in portions  67  project laterally from the opposite sides of the main portion  64 . The press-in portions  67  include a preceding press-in portion  65  disposed to be mounted first into the base wall  21  and a succeeding press-in portion  66  disposed to be mounted later into the base wall  21 . The preceding press-in portion  65  preferably has a shorter projecting distance from the lateral edge of the main portion  64  than the succeeding press-in portion  66 . 
   Each press-in portion  67  has a slanted edge  68  to gradually reduce the projecting distance toward the front with respect to the inserting direction ID. The slanted edge of the preceding press-in portion  65  is connected to a tip  69  via a smooth curved transition, whereas the slanted edge  68  of the succeeding press-in portion  66  is connected to a tip  69  via a non-smooth angled transition (i.e. the first derivative of the curve is non-continuous). The preceding press-in portions  65  are mounted smoothly into the base wall  21  because of their short projecting distance and the curved outer rear ends of the slanted edges  68 . The succeeding press-in portions  66  are fixed strongly to the base wall  21  because of their longer projecting distance and the angled outer rear ends of the slanted edges  68 . 
   The terminal fitting  60  also is formed with projections  71  projecting out in the width direction from the opposite lateral edges of the main portion  64  at a position behind the press-in portions  67  with respect to the inserting direction ID and towards the terminal connecting portion  61 . The projections  71  are substantially rectangular and have a longer projecting distance from the lateral edges of the main portion  64  than the press-in portions  67 . Thus, the terminal fitting  60  is wider at the projections  71 . The projections  71 , the press-in portions  67  and the main portion  64  have substantially the same thickness, and the projections  71  and the press-in portions  67  are transversely symmetrical with respect to the widthwise center of the main portion  64 .  FIGS. 1 to 3  show the large terminal fitting  60 . The small terminal fittings  60  are narrower, but are shaped similarly. 
   The housing  20  is made e.g. of synthetic resin and includes a wide rectangular tubular receptacle  22  with an open front end, as shown in  FIG. 1 . The mating connector is fittable into the receptacle  22 . A lock  23  for holding the mating connector connected projects in a widthwise intermediate position of the ceiling surface of the receptacle  22 . Further, two mounting portions  24  project back at the opposite widthwise ends of the rear end of the receptacle  22  and are placeable on the upper surface of the circuit board  90 . Round holes (not shown) are formed in the lower end surfaces of the mounting portions  24 , and extend in the height direction. Tapping screws or the like can be tightened in these round holes from the side of the circuit board  90  to fix the connector  10  onto the circuit board  90 . 
   A base wall  21  extends vertically in the height direction at the back of the receptacle  22 . Through holes  25  are formed in upper and lower levels of the base wall  21 , and the terminal fittings  60  are pressed through the through holes  25  and held therein. As shown in  FIG. 5 , the through holes  25  arrayed in a widthwise intermediate part of the housing  20  correspond to the small terminal fittings  60 , whereas the through holes  25  arrayed at opposite widthwise sides of the housing  20  correspond to the large terminal fittings  60 . 
   As shown in  FIG. 2 , the inner surface of each through hole  25  includes at least one incline  26 , restrictions  27  and a straight portion  28  in this order from the front (rear with respect to the inserting direction ID of the terminal fitting  60 ). 
   The incline  26  is widened gradually towards the front surface of the base wall  21  and guides the terminal fitting  60  towards the center of the through hole  25 . More specifically, as shown in  FIG. 4 , the incline  26  has two slants  31  aligned to taper the through hole  25  from the front surface of the base wall  21  towards the rear surface of the base wall  21 . The slants  31  form a substantially rectangular frame-like edge  29  at the front surface of the base wall  21 , and the rear edges of the slants  31  are arranged substantially parallel in a vertical plane. The spacing between the rear edges of the slants  31  is substantially equal to the thickness of the projections  71 , the press-in portions  67  and the main portion  64  of the terminal fitting  60 . The incline  26  is at a position substantially corresponding to the projections  71  of the terminal fitting  60  so that the slants  31  cover the projections  71 . Wall surfaces  32  extend substantially vertically at opposite widthwise ends of the incline  26 . 
   The straight portion  28  extends substantially straight in forward and backward directions to the rear surface of the base wall  21 . More particularly, the straight portion  28  is defined by left and right facing surfaces  33  for receiving the press-in portions  67  of the terminal fitting  60  and upper and lower facing surfaces  34  for facing the opposite plate surfaces of the main portion  64  of the terminal fitting  60 . The upper and lower facing surfaces  34  of the straight portion  28  are at the same sides as the slants  31  of the incline  26  and the front ends thereof are substantially continuous with the tapered end of the incline  26 . The upper and lower facing surfaces  34  of the straight portions  28  are recessed and are substantially vertically symmetrically so as not contact the entire plate surfaces of the main portion  64 . Additionally, the facing surfaces  34  are mountain-shaped and concave in cross section so that parts of the facing surfaces  34  corresponding to widthwise intermediate parts of the plate surfaces of the main portion  64  are most distant from these plate surfaces. 
   The left and right facing surfaces  33  of the straight portion  28  include substantially vertically arranged press-in areas for engaging the press-in portions  67 . The press-in areas of the left and right facing surfaces  33  are wider than the main portion  64  of the terminal fitting  60 , but narrower than the press-in portions  67 . Thus, the press-in portions  67  contact and bite into the left and right facing surfaces  33  for pushing the left and right facing surfaces  33  outwardly in the width direction. A retaining force for the terminal fitting  60  is increased by the biting engagement of both the preceding press-in portions  65  and succeeding press-in portions  66 . 
   The restrictions  27  position the rear part of the projection  71  of the terminal fitting  60  towards the center of the through hole  25 , and is formed by three mutually orthogonal surfaces for restraining the widthwise outer end of the rear part of the projection  71  in the thickness direction. The restrictions  27  are arranged between the incline  26  and the left and right facing surfaces  33  of the straight portion  28  and are at positions substantially continuous with the opposite widthwise ends of the taper of the incline  26 . More specifically, each restriction  27  is substantially continuous with the left or right facing surface  33  of the straight portion  28  and includes a step  35 , a lateral end surface  36  and upper and lower main surfaces  37 . The step  35  faces the front end of the projection  71 . The lateral end surface  36  is between the vertical wall  32  of the incline  26  and the step  35  and faces the widthwise outer edge of the rear part of the projection  71 . The upper and lower main surfaces  37  are between the slants  31  of the incline  26  and the step  35  to sandwich the rear part of the projection  71  in the thickness direction. The main surfaces  37  of the restriction  27  are flat and extend substantially straight in a horizontal direction from the rear edges of the slants  31  of the incline  26  to the step  35 . The spacing between the main surfaces  37  substantially equals the thickness of the projection  71 . A positioning space  38  is defined by the main surfaces  37 , the lateral end surface  36  and the step  35  for holding the rear part of the projection  71  and to prevent any loose movements. As shown in  FIG. 6 , the inner surface of the through hole  25  corresponding to the narrow terminal fitting  60  is formed similarly. 
   Upon mounting the terminal fitting  60  through the base wall  21 , the board connecting portion  62  of the terminal fitting  60 , prior to forming the bend  63 , is oriented towards the front surface of the base wall  21  of the housing  20 . The terminal fitting  60  then is inserted substantially horizontally in the inserting direction ID into the through hole  25  in this state. The incline  26  centers the board connecting portion  62  and corrects the inserting posture of the terminal fitting  60  during insertion of the terminal fitting  60  to ensure a smooth inserting operation. Further, the main portion  64  of the terminal fitting  60  passes the upper and lower facing surfaces  34  of the straight portion  28  of the through hole  25  without contact during insertion of the terminal fitting  60  so that no frictional resistance is produced. 
   The press-in portions  67  face the left and right facing surfaces  33  of the straight portion  28  when a final stage of the inserting operation is reached. Thus, the preceding press-in portions  65  and the succeeding press-in portions  66  are pressed successively into the press-in areas with the slanted edges  68  in the lead so as to bite in and engage the straight portion  28 . Simultaneously, the projections  71  enter between the main surfaces  31  of the incline  26  and the rear parts of the projections  71  enter the positioning spaces  38  to be sandwiched in the thickness direction by the main surfaces  37  of the restrictions  27 . The terminal fitting  60  is retained with the press-in portions  67  in an intermediate part of the straight portion  28  in forward and backward directions when the insertion is completed. The rear ends of the projections  71  face the steps  35  of the restrictions  27  to prevent the terminal fitting  60  from being pushed any further forward. Thus, the terminal fitting  60  is held centered and the restriction  27  prevents loose movements of the projections  71 . 
   The terminal fittings  60  then are bent substantially perpendicularly down towards the circuit board  90  at intermediate positions to form the bends  63  so that the board connecting portions  62  extend down. The board connecting portions  62  then are inserted into the through holes of the circuit board  90  and are connected electrically with conductive paths of the circuit board  90  e.g. by soldering, welding, press-fitting, insulation displacement or the like. Further, the mating connector is fit into the receptacle  22  of the housing  20  to connect the terminal connecting portions  61  of the terminal fittings  60  with the respective mating terminal fittings. 
   As described above, front areas of the projections  71  with respect to the inserting direction ID are held by the restrictions  27  of the through holes  25  so as not to move loosely for positioning the terminal fittings  60 . Thus, the terminal fittings  60  are aligned and centered, and it is not necessary to provide the press-in portions  67  with large press-in margins engageable with the press-in areas for alignment adjustment. Hence, the inserting forces for the terminal fittings  60  are low. Furthermore, the straight portions  28  of the through holes  25  include the recessed surfaces that do not contact the facing plate surfaces of the terminal fittings  60 . Therefore, the insertion forces for the terminal fittings  60  are reduced further. Accordingly, abrasion and damage of the plate surfaces of the terminal fittings  60  is prevented and contact reliability is improved. 
     FIG. 7  shows a second embodiment of the invention. The second embodiment has a base wall  21  with through holes  25  that have inner surfaces with a straight portion  28  configured differently than in the first embodiment. The straight portion  28  of the second embodiment includes recessed surfaces only in a widthwise intermediate part and differs from the straight portion  28  of the first embodiment that has the recessed surfaces over substantially the entire width. 
   The straight portion  28  has mountain-shaped concave recessed surfaces  41  distanced from widthwise intermediate parts of the plate surfaces of the main portion  64  so as not to contact these widthwise intermediate parts and substantially flat surfaces  42  to be achieve surface contact with the opposite widthwise sides of the plate surfaces of the main portion  64 . The recessed surfaces  41  and the flat surfaces  42  are vertically symmetrical. 
   According to the second embodiment, the widthwise intermediate part of the main portion  64  of the terminal fitting  60  does not contact the recessed surfaces  41  of the straight portion  28  during insertion of the terminal fitting  60  into the through hole  25 . Thus, an inserting force for the terminal fitting  60  is low. In addition, after the insertion of the terminal fitting  60  into the through hole  25 , the opposite widthwise sides of the main portion  64  of the terminal fitting  60  are adjacent to the flat surfaces  42  of the straight portion  28  and are sandwiched by the flat surfaces  42  of the straight portion  28 . Thus, the terminal fitting  60  is prevented from shaking even upon the action of an external force. 
   The invention is not limited to the above described and illustrated embodiments. For example, the following embodiments are also embraced by the technical scope of the present invention as defined by the claims. 
   The front areas of the projections with respect to the inserting direction may be held tightly in a pressed state by the restrictions. Then, the terminal fitting is prevented from shaking in an external force acting direction. In this case, the spacing between the main surfaces of the restrictions may be made narrower toward the front with respect to the inserting direction of the terminal fitting to become smaller than the thickness of the projections. 
   The terminal fittings may be inserted into the through holes of the base wall from behind. 
   Three or more press-in portions may be arranged substantially side by side on each lateral edge of the main portion of the terminal fitting. 
   The straight portion of the through hole may be brought substantially into surface contact with the entire plate surfaces of the facing terminal fitting. 
   The terminal fittings may be formed straight without being bent in an L-shape or may have any other configuration as needed.