Abstract:
A connector ( 10 ) includes an insulative housing ( 11 ) having a plurality of terminal-receiving cavities ( 17 ). A plurality of conductive terminals ( 20 ) are mounted in the terminal-receiving cavities with each terminals having a contacting portion ( 21 ), a terminating portion ( 24 ), and a retention portion ( 22 ). The retention portion has at least one barb member ( 26 ) projecting therefrom and at least one reentrant portion ( 27 ) extending thereinto. The reentrant portion is positioned adjacent the barb member and in front of the barb member along the terminal insertion direction such that material displaced by the barb member is received in the reentrant portion during insertion of the terminal into the terminal-receiving cavity.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a printed circuit board connector. 
         [0003]    2. Description of the Related Art 
         [0004]    Conventionally, a connector has been mounted on a substrate, such as a print circuit board, for use in connecting the substrate to other electric circuits and the like (for example, refer to Japanese Utility Model Publication (kokoku) No. H6-32769). This kind of connector has a plurality of terminals projecting from the connector housing. 
         [0005]      FIG. 7  is a sectional view showing a part of a conventional connector. 
         [0006]    As shown in  FIG. 7 , a reference numeral  301  designates a box-shaped housing for a connector mounted on a circuit substrate (not shown), made of insulating material. Further, a reference numeral  305  designates a terminal made of electrically conductive material, and mounted on the housing  301  and bottom plate  302 . Then, a mating connector (not shown) is fit into the connector from above in the figure so as to electrically connect to the connector. 
         [0007]    The terminal  305  includes a body portion  306 ; a connection portion  307  electrically connecting to a terminal of the mating connector by contacting therewith; an insertion portion  308 , which is the root part of the connection portion  307  and fits into a terminal through-hole  303  formed on the bottom plate  302  of the housing  301 ; a solder tail portion  312  soldered to a contact pad of a circuit substrate (not shown); and a fixing projection  310  for fixing the terminal  305  to the housing  301 . Further, the bottom plate  302  of the housing  301  has the terminal through-hole  303 , into which the insertion portion  308  of the terminal  305  fits, and a fixing concave portion  304 , into which the fixing projection  310  is inserted. Then, the terminal  305  is mounted in the housing  301  by inserting the insertion portion  308  into the terminal through-hole  303  and inserting the fixing projection  310  into the fixing concave portion  304  from the lower side of the bottom plate  302 . In this instance, an barb  309  formed along the sides of the insertion portion  308  engages with the inner circumference wall of the terminal through-hole  303 , and an engagement convex portion  311  formed along the sides of the fixing projection  310  engages with the inner circumference wall of the fixing concave portion  304 . Therefore, the terminal  305  is firmly mounted in the housing  301 , and does not detach from the housing  301 . 
         [0008]    However, in the conventional connector, when the insertion portion  308  of the terminal  305  is inserted into the terminal through-hole  303  of the housing  301 , the barb  309  of the insertion portion  308  inserted into the terminal through-hole  303  from below the bottom plate  302  pushes aside a portion of the inner circumference wall of the terminal through-hole  303 , and therefore, a rise  313  is formed on the upper surface of the bottom plate  302  around the terminal through-hole  303 , in some cases. Especially, when the connecter is downsized, the bottom plate  302  becomes thin in thickness (for example, less than 1 mm), and the barb  309  almost reaches to the upper surface of the bottom plate  302 , therefore the rise  313  is easily formed. 
       SUMMARY OF THE INVENTION 
       [0009]    An object of the present invention is to solve the above-mentioned problem in the conventional connectors and to provide a connector free from terminal detachment from the housing. This is accomplished by forming an anchor concave portion in a position adjoining the upper side of an barb formed along the sides of the insertion portion of the terminal, and which a periphery of the terminal through-hole situated on the upper side of bottom plate of the housing is maintained flat. The retention force between the insertion portion of the terminal and the terminal through-hole increases due to an anchor effect of the barb and the anchor concave portion. 
         [0010]    In order to achieve the above object, the present invention provides a connector comprising a connector body fitting into a mating connector and a terminal held in the connector body and electrically connected to a terminal of the mating connector. The connector body includes a terminal holder plate in which a terminal through-hole is formed; the terminal includes an insertion portion, which is inserted into the terminal through-hole, and a connection portion connecting to the front end of the insertion portion along an insertion direction and contacting a terminal of the mating connector. The insertion portion includes an barb projecting outwards from the sides of the terminal and digging into a sidewall of the terminal through-hole. The insertion portion also includes an inward reentrant anchor concave portion formed in a position adjoining a front side of insertion direction of the barb. The anchor concave portion is not exposed from a front surface of the terminal holder plate along the insertion direction when the terminal is fully seated in the terminal holder plate. 
         [0011]    Another object of the present invention is to provide a sidewall of the terminal through-hole including a hollow portion, which is formed on a back side of the insertion direction of the barb by being pushed aside by the barb, and a bulge, which is formed on the front side of the insertion direction of the barb and enters the anchor concave portion. Preferably, a volume of the bulge is equivalent to a volume of the portion pushed aside by the barb. 
         [0012]    Another object of the present invention is to provide a terminal holder plate including an auxiliary concave portion formed on a surface on the back side of the insertion direction, the terminal includes a body portion connected at a back end of the insertion direction of the insertion portion and an auxiliary projection extending from the body portion along the insertion direction, and the auxiliary projection is caught by being inserted into the auxiliary concave portion. 
         [0013]    Still, another object of to the present invention is to provide, in the connector, an anchor concave portion formed in a position adjoining an upper side of an barb formed along the sides of an insertion portion of a terminal. Therefore, a periphery of the terminal through-hole situated on an upper side of bottom plate of a housing may be maintained flat, and also insertion force between the insertion portion of the terminal and the terminal through-hole increases due to an anchor effect of the barb and the anchor concave portion, by which the terminal will not detach from the housing. 
         [0014]    A connector includes an insulative housing with a plurality of terminal-receiving cavities for receiving terminals inserted therein in a terminal insertion direction. A plurality of conductive terminals are provided with each terminal being mounted in one of the terminal-receiving cavities. Each of the conductive terminals includes a contacting portion, a terminating portion and a retention portion. The retention portion includes at least one barb member projecting therefrom and at least one reentrant portion extending thereinto. The reentrant portion is positioned adjacent the barb member and in front of the barb member along the terminal insertion direction such that material displaced by the barb member is received in the reentrant portion upon insertion of the terminal into its terminal-receiving cavity. 
         [0015]    The conductive terminals may include an auxiliary retention portion laterally offset from the retention portion relative to the terminal insertion direction. The housing may include a plurality of side walls and a bottom wall cooperatively defining an opening for receiving a mating connector. The terminal-receiving cavities may be formed in the bottom wall of the housing. The reentrant portion of each terminal may be positioned within one of the terminal-receiving cavities. 
         [0016]    A connector includes an insulative housing with a plurality of terminal-receiving cavities and a plurality of conductive terminals inserted into the terminal-receiving cavities in a terminal insertion direction. Each of the conductive terminals includes a contacting portion, a terminating portion and a retention portion. The retention portion includes at least one barb member projecting from the retention portion and at least one reentrant portion extending into the retention portion. The reentrant portion is positioned adjacent to and in front of the barb member in the insertion direction. The retention portion further includes an auxiliary retention portion laterally offset from the retention portion and includes a projection that is inserted into a recess formed in the insulative housing. Material displaced by the barb member during insertion of the terminal into the terminal-receiving cavity is received in the reentrant portion. 
         [0017]    The housing may include a plurality of side walls and a bottom wall cooperatively defining an opening for receiving a mating connector. The terminal-receiving cavities may be formed in the bottom wall of the housing. The reentrant portion of each conductive terminal may be embedded in one of the terminal-receiving cavities. 
         [0018]    A connector includes an insulative housing having side surfaces and a bottom surface interconnecting the side surfaces with the side surfaces and bottom surface defining an opening for receiving a mating connector. The bottom surface has a plurality of terminal-receiving passageways extending therethrough. A plurality of conductive terminals are inserted into the terminal-receiving passageways in a terminal insertion direction. Each of the conductive terminals includes a contacting portion, a terminating portion and a retention portion. The retention portion includes at least one barb member projecting therefrom and at least one reentrant portion extending thereinto. The reentrant portion is located adjacent the barb member and in front of the barb member relative to the insertion direction such that material displaced by the barb member during insertion into the terminal-receiving cavity is received in the reentrant portion. 
         [0019]    Each of the conductive terminals may include an auxiliary retention portion laterally offset from the retention portion and along the insertion direction. Each reentrant portion of the retention portion may be completely within one of the terminal receiving cavities within the bottom wall of the housing. 
         [0020]    Other objects, features and advantages of the present invention will be apparent from the following detailed description taken in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]      FIG. 1  is a side view showing a connector according to an embodiment of the present invention. 
           [0022]      FIG. 2  is a plan view showing the connector according to the embodiment of the present invention. 
           [0023]      FIG. 3  is a sectional view showing the connector according to the embodiment of the present invention and is a sectional view AA of  FIG. 2 . 
           [0024]      FIG. 4  is a front view showing a connector terminal according to the embodiment of the present invention. 
           [0025]      FIG. 5  is a side view showing the connector terminal according to the embodiment of the present invention. 
           [0026]      FIG. 6  is a diagram showing an engagement state of an insertion portion of the terminal and the sidewall of a terminal through-hole according to the embodiment of the present invention and is an enlarged view of B part shown in  FIG. 3 . 
           [0027]      FIG. 7  is a sectional view showing a part of a prior art connector. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0028]    An embodiment of the present invention is described below in detail with reference to the accompanying drawings. 
         [0029]      FIG. 1  is a side view showing a connector according to the embodiment of the present invention,  FIG. 2  is a plan view showing the connector according to the embodiment of the present invention,  FIG. 3  is a sectional view showing the connector according to the embodiment of the present invention and is a sectional view AA of  FIG. 2 ,  FIG. 4  is a front view showing a connector terminal according to the embodiment of the present invention, and  FIG. 5  is a side view showing the connector terminal according to the embodiment of the present invention. 
         [0030]    As shown in  FIG. 3 , connector ( 10 ) according to the embodiment of the present invention, is mounted on a circuit substrate (not shown) and fit into the mating connector (not shown) to electrically connect the circuit substrate to a cable or a circuit substrate connected to the mating connector. In this embodiment, representations of directions such as “up”, “down”, “left”, “right”, “front”, “rear”, and the like, used for explaining a structure and movement of each part of the connector  10 , are not absolute, but relative. These representations are appropriate when the connecter  10  is in the position shown in  FIG. 3 . If the position of the connector  10  changes, however, it is assumed that these representations are to be changed according to the change of the position of the connector  10 . 
         [0031]    The connector  10  is formed from an insulating material, and includes a housing  11  and a plurality of conducting terminals  20 , mounted so as to pass through terminal through-holes  17  formed in a bottom wall  16  as a terminal holder plate in the housing  11 . In the shown example, terminals  20 , twenty in total, are disposed in 2 rows with 1.0-mm pitches. However, the number of the terminals  20 , the pitch, and the number of the rows may be arbitrarily changed. For example, the terminals  20  may be disposed in one row or more than 2 rows. Additionally, not all terminal through-holes  17  need to have the terminals  20 . Some terminals  20  may be omitted as necessary so as to correspond to the arrangement of the mating connecter. 
         [0032]    The housing  11  is almost a rectangular parallelepiped box in shape. The housing  11  includes side walls and a bottom wall  16  that define an interior that opens as shown in  FIG. 3 . A side of the housing  11  which fits into the mating connecter, that is, an end surface of the fitting side, is open, and serves as a fitting opening  12  into which the mating connector (not shown) fits. Further, the engagement bulge  14 , as a lock member for locking the mating connector by engaging with an engagement arm portion of the mating connector, is formed as a unit near the upper end of a side of the housing  11 . Further, an engagement opening portion  14   a  for engaging with an engaging projection of the engagement arm portion is formed on the engagement bulge  14 . A sidewall  13  opposing to the engagement bulge  14  has an almost flat surface. The connector  10  is a so-called “straight-type” or vertical mount connector, and is mounted on a circuit substrate (not shown) in a standing condition, in other words, in the state where an opening is facing upward. 
         [0033]    In this embodiment, the terminals  20  are formed in a shape shown in  FIG. 3 to 5  by applying a process, such as stamping, to an electrically conductive metal plate. The terminal  20  includes a connection portion  21 , which extends in a direction from the bottom wall  16  of the housing  11  to the fitting opening  12  (upward in  FIG. 3 ) so as to be electrically connected to the mating connector by contacting the terminal of the mating connector; an insertion or mounting portion  22 , which is the root or base of the connection portion  21  and inserted into a terminal through-hole  17  formed in the bottom wall  16 ; a body potion  23 , which extends in parallel with the bottom wall  16  in the outer side of the bottom wall  16  (downward in  FIG. 3 ) so as to be connected to the lower end of the insertion portion  22 ; a tail portion  24 , which is connected to an end part of the body portion  23  close to the outer side of the housing  11  and connected to a contact pad of a circuit substrate (not shown) by soldering and the like, including a fixing projection  25 . An auxiliary projection is inserted into a fixing concave portion  18  as an auxiliary concave portion formed in the outside surface of the bottom wall  16  (the underside in  FIG. 3 ). The auxiliary projection is connected to the end part of the body portion  23  close to the outer side of the housing  11 , extending in the direction of the bottom wall  16 , in other words, in the insertion direction of the insertion portion  22 . Additionally, on both sides of the insertion portion  22 , there are formed a barb or an barb  26  projecting outwards and an inward reentrant anchor concave portion  27  adjoining the upper portion of the barb or barb  26 , that is, the front portion of the insertion direction. Additionally, an engagement convex portion  25   a  projecting outward is formed on both sides of the fixing projection  25 . 
         [0034]    The terminal  20  is mounted on the housing  11  by a manner in which the terminal  20  is moved relatively to the housing  11  from below the bottom wall  16 , the insertion portion  22  is inserted into the terminal through-hole  17  of the bottom wall  16 , and the fixing projection  25  is inserted into the fixing concave portion  18 . In a state where mounting is completed, as shown in  FIG. 3 , an upper end of the bottom portion  23  abuts the bottom surface of the bottom wall  16 , and the connection portion  21  passes through the terminal through-hole  17  and projects into the housing  11 . Further, the engagement convex portion  25   a  of the fixing projection  25  engages with the sidewall of the fixing concave portion  18  so as to dig into the sidewall thereof. Thereby, the fixing projection  25  is firmly caught by the fixing concave portion  18  so as to prevent the fixing projection  25  from detaching from the fixing concave portion  18 . 
         [0035]    Additionally, the barb  26  of the fixing projection  22  engages with the sidewall of the terminal through-hole  17  and if the barb digs into the sidewall thereof. At the same time, a portion of the sidewall pushed aside by the barb  26  is displaced the barb or anchor concave portion  27  so as to engage with the anchor concave portion  27 . Thereby, the insertion portion  22  is firmly fixed to the terminal through-hole  17  and thus displacement of the insertion portion  22  relative to the terminal through-hole  17  may be prevented, and the detachment of the insertion portion  22  from the terminal through-hole  17  may also be prevented. Therefore, when the connector  10  fits into the mating connector, the terminal  20  will not be displaced even if the connection portion  21  of the terminal  20  is subjected to outer force caused by abutting the terminal, and the like, of the mating connector. 
         [0036]    The lower end of the tail portion  24  is connected to the contact pad of the circuit substrate by soldering and the like, and serves as a substrate connection portion electrically connecting to an electrically conductive trace formed on the circuit substrate. Furthermore, the connector  10  is fixed in the circuit substrate by the lower end of the tail portion  24  being connected to the contact pad. 
         [0037]    Next, an engagement state between the insertion portion  22  of the terminal  20  and the sidewall of the terminal through-hole  17  is explained in detail. 
         [0038]      FIG. 6  shows an engagement state between the insertion portion of the terminal and the sidewall of the terminal through-hole according to the embodiment of the present invention, and an enlarged view of B part of  FIG. 3 . 
         [0039]    In this embodiment, as shown in  FIG. 6 , while the width of the terminal through-hole  17  formed in the bottom wall  16  is formed slightly larger than the width of the insertion portion  22  of the terminal  20 , the relationship between the width of the terminal through-hole  17  and the width of the insertion portion  22  may be changed as necessary. Further, while the width of the connection portion  21  of the terminal  20  is formed almost the same as the width of the insertion portion  22 , the relationship between the width of the connection portion  21  and the width of the insertion portion  22  may be changed as necessary. Moreover, a taper portion  19  is formed in the bottom edge portion of the bottom wall  16  in the terminal through-hole  17  so as to facilitate insertion of the connection portion  21  and the insertion portion  22  of the terminal  20 . However, the taper portion  19  may be omitted as necessary. 
         [0040]    As described above, since the bottom wall  16  is made of insulating material, which is softer than the conductor terminal  20 , when the insertion portion  22  inserts upwards into the terminal through-hole  17 , the barb  26  projecting outwards from the both sides of the insertion portion  22  causes plastic deformation of the insulating material, or the sidewall of the terminal through-hole  17 . In this case, since the barb  26  moves upward while digging into the sidewall of the terminal through-hole  17 , the portion of the sidewall situated above the barb  26  is pushed aside by the barb  26  and moved upward. Therefore, a hollow portion  17   a  is formed after the barb  26  has passed through a part of the sidewall, in other words, formed below the barb  26 , by the barb  26  pushing aside the sidewall. The hollow portion  17   a  almost corresponds to the passing trail made by the barb  26  moving upward while digging into the sidewall of the terminal through-hole  17 . 
         [0041]    On the other hand, the portion of the sidewall which is pushed aside is gathered in the front part of the barb  26  along the moving direction, that is, a portion above the barb  26 . In this state, since the inward reentrant anchor concave portion  27  is formed in a place which is adjacent to the upper part of the barb  26 , the gathered portion of the deformed sidewall enters the reentrant portion or anchor concave portion  27 , thereby forming the bulge  17   b  where a part of the sidewall is protruding. Therefore, the gathered portion of the sidewall is moved upwards, thereby preventing a formation of the rise  313  as shown in  FIG. 7 , which has been described in the Description of the Related Art section. Moreover, as described above, since the bulge  17   b  enters the reentrant portion  27  and engages with the reentrant portion  27 , the effect of firmly fixing the insertion portion  22  into the terminal through-hole  17 , that is the anchor effect or retention, increases. 
         [0042]    As shown in  FIG. 6 , the barb  26  and the reentrant portion  27  adjacent to the upper part of the barb  26  are formed in a position where the reentrant portion  27  is not exposed from the front surface of the insertion direction of the bottom wall  16 , that is, a position where the reentrant portion  27  is below the upper surface of the bottom wall  16 , in a state where the terminal  20  is completely mounted or embedded into the housing  11 , that is, in a state where the upper end of the body part  23  abuts the lower surface of the bottom wall  16 . Therefore, in a situation where the terminal  20  is completely mounted into the housing  11 , airspace is not formed around the terminal  20  on the upper surface of the bottom wall  16 . Therefore, there is little possibility that foreign substance enters into a space between the bottom wall  16  and the terminal  20 , and also the appearance is not disfigured. Moreover, since the bulge  17   b  is large enough in size to fully engage with the reentrant portion  27 , a sufficient anchor effect may be achieved. 
         [0043]    Additionally, the reentrant portion  27  is formed large enough to accommodate the portion of the sidewall pushed aside by the barb  26 . In this situation, the amount of the portion of the sidewall pushed aside by the barb  26  is to be a value obtained by multiplying the amount of the sidewall of the terminal through-hole  17  into which the barb  26  digs by the amount of movement of the barb  26  inside the terminal through-hole  17 . That is, an area C shown in  FIG. 6  is equivalent to the amount of the portion of the sidewall pushed aside by the barb  26 . The area C designates a volume of the portion pushed aside from the sidewall of the terminal through-hole  17  by the barb  26  entering the terminal through-hole  17 . The area C is equivalent to an amount of area including the hollow portion  17   a  formed below the barb  26  by pushing away the portion of the sidewall, and one part of the barb  26 . 
         [0044]    On the other hand, the portion of the sidewall protruding in a position adjoining an upper side of the barb  26  is equivalent to an area D shown in  FIG. 6 . The amount of the protruding sidewall is equivalent to the amount of the portion of the sidewall pushed aside by the barb  26 , and thus the size of the area D is equivalent to the size of the area C. The area D designates the volume of the portion protruding from the sidewall of the terminal through-hole  17  due to the entering of the barb  26  into the terminal through-hole  17 . The area D is equivalent to the bulge  17   b , and also includes the reentrant portion  27 . 
         [0045]    In this embodiment, the terminal  20  includes an insertion portion  22  inserted into the terminal through-hole  17  formed on a bottom wall  16  of a housing  11 , and a connection portion  21  connected to a front end of insertion direction of the insertion portion  22  and contacting a terminal of the mating connector, the insertion portion  22  includes an barb  26  projecting outwards from both sides of the terminal  20  and digging or skiving into a sidewall of the terminal through-hole  17 , and an inward reentrant anchor concave portion  27  formed in a position adjoining a front part of insertion direction of the barb  26 , and the reentrant portion  27  is not exposed from a front surface of the bottom wall  16 . 
         [0046]    Therefore, a periphery of the terminal through-hole  17  situated on an upper side of bottom wall  16  of the housing  11  may be maintained flat, and also insertion force between the insertion portion  22  of the terminal and the terminal through-hole  17  increases due to an anchor effect of the barb  26  and the reentrant portion  27 , by which the terminal  20  will not detach from the housing  11 . Furthermore, since a rise is not formed on the upper surface of the bottom wall  16  around the terminal  20 , the appearance may be kept good as well. Moreover, since airspace is not formed on the upper surface of the bottom wall  16  around the terminal  20 , there is little possibility that foreign substance enters into a space between the bottom wall  16  and the terminal  20 , and also the appearance is kept good. 
         [0047]    Further, the sidewall of the terminal through-hole  17  includes a hollow portion  17   a  formed on a back side of the insertion direction of the barb  26  by being pushed aside by the barb  26 , and a bulge  17   b  formed on the front side of the insertion direction of the barb  26  and entering the anchor concave portion  27 . Additionally, a volume of the bulge  17   b  is equivalent to a volume of the portion pushed aside by the barb  26 . 
         [0048]    Therefore, the bulge  17   b  is large enough in size to fully engage with the anchor concave portion  27 , and therefore sufficient anchor effect may be achieved. 
         [0049]    Further, the bottom wall  16  includes a fixing concave portion  18  formed on a surface on the back side of the insertion direction, the terminal  20  includes a body portion  23  connected at the back end of the insertion direction of the insertion portion  22 , and a fixing projection  25  extending from the body portion  23  along the insertion direction, and the fixing projection  25  is inserted into the fixing concave portion  18  so as to be caught thereby. The terminal  20  is firmly fixed on the bottom wall  16 , and therefore when the connector  10  fits into the mating connector, the terminal  20  will not detach from the bottom wall  16  or be displaced even if the connection portion  21  of the terminal  20  is subjected to outer force caused by abutting a terminal, and the like, of the mating connector. 
         [0050]    Note that the fixing projection  25  and the fixing concave portion  18  may be omitted if unnecessary. 
         [0051]    It should be noted here that the present invention is not limited to the above embodiment, but can be variously modified and changed within the gist of the invention. Thus the modifications and changes are not excluded from the scope of the present invention.