Abstract:
It is an object of the invention to provide a battery connector in which, even when an engagement piece portion ( 66 ) that is required for applying a preload to a contact ( 57 ) of a contact member ( 5 ) rubs with an engagement face ( 21 ) formed in a wall face of a housing ( 1 ) made of a synthetic resin, possibilities that the engagement face ( 21 ) is shaved, and that the engagement piece portion ( 66 ) is deformed can be eliminated. In the battery connector of the invention, a meandering contact member ( 5 ) is housed in a housing ( 1 ). A mountain-like projection ( 56 ) of the contact member ( 5 ) is projected from an opening ( 16 ) of the housing ( 1 ). An engagement piece portion ( 66 ) formed in the mountain-like projection ( 56 ) is engaged with an engagement face ( 21 ) of the housing ( 1 ) to apply a preload to the contact ( 57 ). The engagement piece portion ( 66 ) has a shape which is free from an angular edge. Specifically, the engagement piece portion ( 66 ) has a planar portion ( 71 ), and projection pieces ( 73, 74 ) which are continuously integrated with the planar portion ( 71 ) through arcuate bent portions ( 72 ). Swollen portions ( 75 ) having an arcuate face may be formed on the planar portion ( 71 ).

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a battery connector which is useful for, for example, charging a battery, and more particularly to a battery connector in which an engagement piece disposed on a contact member is engaged under a preload with an engagement face of a housing.  
           [0003]    2. Description of the Prior Art  
           [0004]    A conventional battery connector of this kind is disclosed in PCT National Patent Publication No. 2001-502837. The disclosed connecter will be described with reference to FIG. 9 or  10 .  
           [0005]    [0005]FIG. 9 is a section view of the conventional battery connector, and FIG. 10 is a perspective view of a contact member which is used in the conventional battery connector.  
           [0006]    In the battery connector, as shown in FIG. 9, a meandering contact member  210  is housed in a housing  200  in which the lower end is placed on a board face of a circuit board  100 . As shown in FIG. 10, the contact member  210  is formed into a meandering shape in which three slender plate piece portions are continuously integrated with one another through two flexible portions  216 ,  217  that are arcuately protruded. As shown in FIG. 9, a mountain-like projection  212  which is formed in the plate piece portion of one end side of the contact member  210  is projected through an oblong opening  205  that is formed in the upper wall of the housing  200 , and its top is formed as a contact  213  which is to be in elastic contact with a battery terminal (not shown). A fix piece  214  which is fixed to a wall  201  of the housing  200 , and a soldering terminal  215  which is foldedly formed to be connected to a pattern on the circuit board  100  are formed in the plate piece portion of the other end side of the contact member  210 . The lower flexible portion  216  is fitted into a hole  203  which is formed in another wall  202  of the housing  200 , and the upper flexible portion  217  is opposed to the wall  201 .  
           [0007]    An end portion of the mountain-like projection  212  of the contact member  210  is bent in a substantially perpendicular manner toward the inner side (in the illustrated example, the lower side) of the mountain-like projection  212 . The folded end portion is provided with a rectangular engagement piece portion  220  which is laterally projected. An end face of the engagement piece portion  220  is in elastic contact under a preload with an engagement face  206  which is formed by a wall face of a peripheral portion of the opening  205 , to be engaged therewith. The degree of projection of the mountain-like projection  212  from the opening  205  of the housing  200  is restricted by the configuration where the engagement piece portion  220  is in elastic contact and engaged with the engagement face  206  under a preload as described above.  
           [0008]    In the battery connector, in an initial state where no external force acts on the contact member  210 , the engagement piece portion  220  is overlappingly in elastic contact with the engagement face  206  of the housing  200  as shown in FIG. 9. When a battery D is to be charged, the battery D is attached to and detached from the connector.  
           [0009]    In the operation of attaching the battery D, the battery D is inserted into the connector in the direction of the arrow C 1  of FIG. 9 which is perpendicular to the compression direction (vertical direction) of the meandering contact member  210 . As a result, the battery D is caused to slide over the mountain-like projection  212  to retract the mountain-like projection  212 , so that a terminal of the battery D is pressed against the contact  213  of the projection to be in elastic contact therewith. At this time, the contact member  210  is compressed, the mountain-like projection  212  is retracted as indicated by the arrow c 1  to be pressed into the opening  205 , and the engagement piece portion  220  separates from the engagement face  206 . As a result of the retraction of the mountain-like projection  212 , a situation in which an arcuate portion  221  of the one end of the contact member  210  strikes against the wall  202 , or the flexible portion  217  strikes against and rubs with the wall  201  sometimes occur. By contrast, in the operation of detaching the battery D, the battery D is separated from the connector in the direction of the arrow C 2  of FIG. 9 which is perpendicular to the expansion direction of the meandering contact member  210 . At this time, the contact member  210  which has been compressed by the flexural deformation is expanded, and the mountain-like projection  212  is displaced as indicated by the arrow c 2 , whereby the mountain-like projection  212  is projected from the opening  205 . As a result, the engagement piece portion  220  is engaged with the engagement face  206 , and the connector is returned to the initial state to be prepared for the next use.  
           [0010]    As shown in FIG. 11 illustratively showing problems of the conventional example, in the conventional example, a situation possibly occurs where the operations of attaching and detaching the battery causes the end face of the engagement piece portion  220  to rub with the engagement face  206  in the direction of the arrow d 1  or d 2  while maintaining the elastic contact with the engagement face. When such a situation occurs, there is the possibility that the engagement piece portion  220  which is a metal portion shaves the engagement face  206  which is a synthetic resin portion, or that the thin engagement piece portion  220  is caught by the engagement face  206  to be deformed.  
           [0011]    When the engagement piece portion  220  shaves the engagement face  206  or the engagement piece portion  220  is deformed, the housing  200  is reduced in strength to be easily cracked or deformed, or the deformation of the engagement piece portion  220  causes the engagement piece portion  220  not to be engaged with the engagement face  206 , so that the engagement piece portion  220  is projected from the opening  205 . As a result, the performance required in a battery connector cannot be exerted.  
         SUMMARY OF THE INVENTION  
         [0012]    The invention has been conducted under the above-discussed circumstances. It is an object of the invention to provide a battery connector in which the shape or the structure of an engagement piece portion is improved, and, even when the engagement piece portion rubs with an engagement face of a housing, there is no possibility that the engagement face is shaved, or that the engagement piece portion is deformed.  
           [0013]    It is another object of the invention to provide a battery connector in which, even when the engagement piece portion of the battery connector which has been described in the conventional example rubs with an engagement face of a housing, possibilities that the engagement face is shaved, and that the engagement piece portion is deformed can be eliminated only by applying a very simple change on the shape or the structure of the engagement piece portion.  
           [0014]    It is a further object of the invention to provide a battery connector which can attain the objects, and in which the height in the case where the connector is mounted on a circuit board can be easily reduced.  
           [0015]    It is a still further object of the invention to provide a battery connector which can attain the objects, and in which the height of a housing can be easily reduced and the strength can be easily enhanced.  
           [0016]    The battery connector of the invention has:  
           [0017]    a meandering contact member in which a plurality of plate piece portions are continuously integrated with one another through one or more arcuate flexible portions;  
           [0018]    a mountain-like projection which is formed in one of the plate piece portions that is on one end side of the contact member, and in which a top is formed as a contact that is to be in elastic contact with a battery terminal;  
           [0019]    a housing which houses the contact member;  
           [0020]    an opening which is formed in the housing, and through which the mountain-like projection is projected;  
           [0021]    an arcuate portion which is formed in the mountain-like projection to be bent toward an inner side of the mountain-like projection, and an engagement piece portion which is laterally projected from an end portion of the arcuate portion; and  
           [0022]    an engagement face which is formed by a rear face of a peripheral portion of the opening, and with which the engagement piece portion is in elastic contact and engaged under a preload, whereby a degree of projection of the mountain-like projection from the opening is restricted.  
           [0023]    The battery connector further has a wall face of the housing that is to confront a board face of a circuit board on which the housing is to be mounted, and that opposes the arcuate portion of the mountain-like projection, and  
           [0024]    the engagement piece portion is displaced in a direction along which the board face of the circuit board and the wall face of the housing confront each other, to be in sliding contact with the engagement face, and has a shape which is free from an angular edge that, when the engagement piece portion is in sliding contact with the engagement face, shaves the engagement face.  
           [0025]    According to the configuration, even when the mountain-like projection is displaced in a direction along which the board confronts the circuit board and the wall face of the housing face each other, a situation where the engagement piece portion shaves the engagement face, or where the engagement piece portion is caught by the engagement face to be deformed does not occur because the engagement piece portion has the shape which is free from an angular edge that shaves the engagement face. Since the configuration in which the engagement piece portion has the shape which is free from an angular edge is employed, a battery connector in which, even when the engagement piece portion rubs with the engagement face of the housing, there is no possibility that the engagement face is shaved, or that the engagement piece portion is deformed can be provided only by applying a very simple change on the shape or the structure of the engagement piece portion of the battery connector which has been described in the paragraph of the prior art.  
           [0026]    In the invention, the configuration may be employed where the engagement piece portion integrally has: a planar portion in which an edge of each of lateral sides is elongated in the confronting direction, and which is slidably contactable with the engagement face; and a projection piece which, in each of sides of a vertical width direction of the planar portion, is elongated through an arcuate bent portion in a direction away from the engagement face.  
           [0027]    The configuration may be employed where the engagement piece portion integrally has: a planar portion; and a swollen portion which is formed on the planar portion, and which comprises an arcuate face that is to butt against the engagement face to hold the planar portion to a position separated from the engagement face.  
           [0028]    Preferably, the housing is configured so that a portion that is opposed to a wall face of the housing to which the arcuate portion of the mountain-like projection is opposed is formed as an aperture, and the aperture is closed by the circuit board on which the housing is to be placed. When this configuration is employed, no wall exists in the portion where the aperture is formed, and hence the height of the housing can be correspondingly reduced.  
           [0029]    Preferably, the housing has: a surrounding wall having the opening; a supporting wall which is opposed to the surrounding wall; and a covering wall which extends between upper ends of the surrounding wall and the supporting wall one of the plate piece portions that is on another end side of the contact member is placed to overlap with the supporting wall, and one of the flexural portions which is continuously integrated with the plate piece portion of the other end side is fitted into a recess formed in the covering wall. When this configuration is employed, the configuration acts synergistically with the structure in which the aperture is formed in the housing, to further enhance the reduction of the height of the housing.  
           [0030]    Preferably, a lower half of the surrounding wall is forward projected, and a reinforcing wall which closes a lower portion of the opening is formed integrally on the projected portion. Preferably, the reinforcing wall is disposed in each of right and left or two places of the projected portion, and a reinforcement terminal which reinforces the housing is placed in a recess between the reinforcing walls. When this configuration is employed, the housing is reinforced by the reinforcing walls and the reinforcement terminal, and hence the strength of the housing is correspondingly enhanced.  
           [0031]    As described above, in the battery connector of the invention, even when the engagement piece portion rubs with the engagement face of the housing, the possibilities that the engagement face is shaved, and that the engagement piece portion is deformed are eliminated. Therefore, it is possible to provide a battery connector in which situations where, as a result of use, the housing is early cracked or deformed because of insufficient strength, or where the contact member is deformed do not occur, and the initial performance can be exerted for a long term. The height in the case where the connector is mounted on a circuit board can be easily reduced. Therefore, the battery connector and hence an apparatus in which the battery connector is mounted can be readily miniaturized. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0032]    [0032]FIG. 1 is a front view of a battery connector according to the invention;  
         [0033]    [0033]FIG. 2 is a section view taken along line II-II of FIG. 1;  
         [0034]    [0034]FIG. 3 is a section view taken along line III-III of FIG. 1;  
         [0035]    [0035]FIG. 4 is a partial perspective view showing the shape of an engagement piece portion;  
         [0036]    [0036]FIG. 5 is a view illustrating the function enlargedly showing main portions of FIG. 3;  
         [0037]    [0037]FIG. 6 is an enlarged view of portion VI of FIG. 1;  
         [0038]    [0038]FIG. 7A is a perspective view showing a modification of the engagement piece portion, and FIG. 7B is an enlarged section view taken along line VIIB-VIIB of FIG. 7A;  
         [0039]    [0039]FIG. 8 is a view illustrating the function which is exerted by the engagement piece portion of FIGS. 7A and 7B;  
         [0040]    [0040]FIG. 9 is a section view of a conventional battery connector;  
         [0041]    [0041]FIG. 10 is a perspective view of a contact member which is used in the conventional battery connector; and  
         [0042]    [0042]FIG. 11 is a view showing problems of the conventional example. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0043]    As shown in FIG. 1 or  2 , the battery connector comprises a housing  1  formed by a molded product of a synthetic resin, and a contact member  5  formed by a metal piece which is housed in an internal space of the housing  1 .  
         [0044]    As shown in FIG. 2 or  3 , the contact member  5  is configured by continuously integrating three slender plate piece portions  51 ,  52 ,  53  in a meandering manner with one another through flexible portions  54 ,  55  that are arcuately protruded. A mountain-like projection  56  is formed in the plate piece portion  53  of one end side of the contact member  5 , and the top of the mountain-like projection  56  is formed as a contact  57  which is to be in elastic contact with a battery terminal (not shown). The plate piece portion  51  of the other end side of the contact member  5  is placed so as to overlap with a supporting wall face  12  of the housing  1 , and the flexible portion  54  which is continuously integrated with the plate piece portion  51  is fitted into a recess (in the illustrated example, a hole) formed in a covering wall  13  of the housing  1 . An end portion of the plate piece portion  51  is perpendicularly bent to be formed as a terminal  58  which is projected to the rear side of the housing  1 . By contrast, the housing  1  has an oblong opening  16  formed in a surrounding wall  15 . A lower half of the surrounding wall  15  is forward projected, and reinforcing walls  18  which close a lower portion of the opening  16  are formed integrally on the projected portion  17 . In the housing  1 , a portion that is opposed to the covering wall  13  is formed as an aperture  19 . In the state where the housing  1  is placed on a board face of a circuit board  100  as shown in the figure, the aperture  19  is closed by the circuit board  100 .  
         [0045]    As shown in FIG. 3, the mountain-like projection  56  of the contact member  5  comprises: an arcuate portion  65  which is bent toward the inner side (in the illustrated example, the lower side) of the mountain-like projection  56 , to be opposed to a wall face  13   a  of the covering wall  13  of the housing  1 ; and an engagement piece portion  66  which is laterally stretched from an end portion of the arcuate portion  65 . The engagement piece portion  66  is in elastic contact and engaged under a preload with a rear face of a peripheral portion of the opening  16  of the housing  1 , i.e., an engagement face  21  which is formed by a rear face of the surrounding wall  15 . Since the engagement piece portion  66  is in elastic contact and engaged under a preload with the engagement face  21 , the degree of projection of the mountain-like projection  56  from the opening  16  of the housing  1  is restricted. As shown in FIG. 6, predetermined interspaces  16   a  are ensured between right and left peripheral portions of the opening  16  and the mountain-like projection  56 . The interspaces  16   a  prevent the mountain-like projection  56  from being in contact with the periphery when the projection is advanced or retracted. When the mountain-like projection  56  is displaced, therefore, a situation where the mountain-like projection  56  rubs with the periphery to shave it, or where the mountain-like projection  56  is deformed hardly occurs.  
         [0046]    As shown in FIG. 4, the engagement piece portion  66  of the contact member  5  is formed into a shape which is stretched in both the lateral sides from the end portion of the arcuate portion  65  formed in the mountain-like projection  56 . The engagement piece portion  66  integrally has: a rectangular planar portion  71  which is laterally elongated; and a pair of projection pieces  73 ,  74  which are on the sides of the vertical width direction of the planar portion  71 , respectively, and which are elongated through arcuate bent portions  72 . In the illustrated example, the upper projection piece  73  is formed into a shape in which the piece is divided into sub-pieces that are on the sides of the end portion of the arcuate portion  65 , respectively. An edge  68  of each lateral side of the engagement piece portion  66  is elongated in the longitudinal direction of the opening  16  of the housing  1 , i.e., the direction (vertical direction) along which, when the housing  1  is placed on the board face of the circuit board  100  as shown in FIG. 3, the inner wall face  13   a  of the covering wall  13  confronts the circuit board  100 . Even when the engagement piece portion  66  is displaced in the vertical direction indicated by the arrow a 1 ′ or a 2 ′ of FIG. 3 while maintaining the elastic contact with the engagement face  21 , therefore, the edges  68  of the lateral sides of the engagement piece portion  66  do not shave the engagement face  21 .  
         [0047]    In an initial state where no external force acts on the contact member  5 , as shown in FIG. 5, the planar portion  71  of the engagement piece portion  66  is overlappingly in surface contact with the engagement face  21  of the housing  1  in an elastically pressed state, and the upper and lower projection pieces  73 ,  74  are elongated in a direction away from the engagement face  21 . Furthermore, the arcuate portion  65  of the mountain-like projection  56  confronts the wall face  13   a  of the covering wall  13  of the housing  1  via a small gap. In the embodiment, a reinforcement terminal  23  is placed in a recess  22  between the right and left reinforcing walls of the housing  1  to reinforce the housing  1  (see FIG. 1 or FIG. 2).  
         [0048]    In the battery connector, in a process of, for example, charging a battery D, the operations of attaching and detaching the battery D are performed.  
         [0049]    In the operation of attaching the battery, the battery D is inserted into the connector in the direction of the arrow A 1  of FIG. 3 which is parallel to the compression direction of the meandering contact member  5 , whereby a terminal of the battery is pressed against the contact  57  of the mountain-like projection  56  to be in elastic contact therewith. At this time, the contact member  5  is compressed mainly by means of the flexural deformation of the flexible portions  54 ,  55 , the mountain-like projection  56  is retracted as indicated by the arrow a 1  to be pressed into the opening  16 , and the engagement piece portion  66  separates from the engagement face  21 . As a result of the retraction of the mountain-like projection  56 , a situation in which the arcuate portion  65  strikes against and rubs with the wall face  13   a  of the covering wall  13  sometimes occurs. By contrast, in the operation of detaching the battery D, the battery D is separated from the connector in the direction of the arrow A 2  of FIG. 3 which is parallel to the expansion direction of the meandering contact member  5 . At this time, the contact member  5  which has been compressed by the flexural deformation is expanded, and the mountain-like projection  56  is forward displaced as indicated by the arrow a 2 , so as to be projected from the opening  16 . As a result, the engagement piece portion  66  is engaged with the engagement face  21 , and the connector is returned to the initial state to be prepared for the next use. In the usual battery attaching operation, therefore, a situation where the engagement piece portion  66  rubs with the engagement face  21  seldom occurs. In some cases, however, when the mountain-like projection  56  is displaced forward or rearward, a situation may possibly occur where the engagement piece portion  66  rubs with the engagement face  21  in only a short length range.  
         [0050]    The case will be considered where an external force in the direction indicated by the arrow A 1 ′ or A 2 ′ of FIG. 3 is applied to the mountain-like projection  56  for any reason and the engagement piece portion  66  slides in the direction indicated by the arrow a 1 ′ or a 2 ′ while maintaining the elastic contact with the engagement face  21 . In this case, a situation may possibly occur in which the planar portion  71  of the engagement piece portion  66  which has been described with reference to FIG. 4 overlaps and rubs with the engagement face  21  in a surface contact state, or in which the engagement piece portion  66  is inclined to rub with the engagement face  21  as indicated by the phantom line in FIG. 5. In the situation in which the planar portion  71  overlaps and rubs with the engagement face  21 , since the planar portion  71  has no angular edge that may shave the engagement face  21 , the engagement face  21  is not shaved, and the engagement piece portion  66  is not caught by the engagement face  21  to be deformed. Also when the situation in which the engagement piece portion  66  is inclined to rub with the engagement face  21  occurs, the arcuate bent portions  72  of the engagement piece portion  66  rubs with the engagement face  21  as indicated by the phantom line in FIG. 5. In this case also, therefore, the engagement face  21  is not shaved, and the engagement piece portion.  66  is not caught by the engagement face  21  to be deformed.  
         [0051]    As a result of advancing or retracting displacement of the mountain-like projection  56 , the arcuate portion  65  may sometimes strike against and rub with the wall face  13   a  of the covering wall  13 . In this case, since no angular edge which may shave the wall face  13   a  exists in the arcuate portion  65 , the wall face  13   a  is not shaved, and the mountain-like projection  56  is not deformed.  
         [0052]    In the embodiment, the housing  1  is configured so that the portion opposed to the covering wall  13  is formed as the aperture  19  or a wall in the portion is omitted, and, when the housing  1  is placed on the board face of the circuit board  100 , the aperture  19  is closed by the circuit board  100 . Furthermore, the flexible portion  54  of the contact member  5  is fitted into the recess  14  of the covering wall  13 . Therefore, reduction of the height of the housing  1  is realized. The strength of the surrounding wall  15  having the opening  16  is improved by the reinforcing walls  18  formed on the projected portion  17  in the lower half of the surrounding wall  15  in which the opening  16  is formed. Consequently, the connector has an advantage that the whole is small in size and excellent in strength.  
         [0053]    [0053]FIG. 7A is a perspective view showing a modification of the engagement piece portion  66 , FIG. 7B is an enlarged section view taken along line VIIB-VIIB of FIG. 7A, and FIG. 8 is a view illustrating the function which is exerted by the engagement piece portion  66  of FIGS. 7A and 7B.  
         [0054]    In the engagement piece portion  66  of FIGS. 7A and 7B, a spherical swollen portion  75  is formed in each of right and left sides of the rectangular planar portion  71 . In the engagement piece portion  66 , as shown in FIG. 8, the swollen portions  75  butt against the engagement face  21  to hold the planar portion  71  to a position separated from the engagement face  21 . Even when, in an abnormal state, an accidental situation occurs where the engagement piece portion  66  slides in the direction indicated by the arrow a 1 ′ or a 2 ′ while maintaining the elastic contact with the engagement face  21 , therefore, only the swollen portions  75  of the engagement piece portion  66  overlap and rub with the engagement face  21 , so that the engagement face  21  is not shaved and the engagement piece portion  66  is not caught by the engagement face  21  to be deformed. The above similarly occurs also in a situation where, in a battery attaching operation in a normal state, the engagement piece portion  66  rubs with the engagement face  21 . When the swollen portions  75  having no angular edge in the engagement piece portion  66  rub with the engagement face  21  as in this example, particularly, the frictional resistance between the swollen portions  75  and the engagement face  21  is suppressed to a low degree and the sliding property is improved. Therefore, an excessive force is hardly applied to the mountain-like projection  56  and hence to the contact member  5 , thereby producing an advantage that the durability of the contact member is improved.  
         [0055]    The shape of the swollen portions  75  is not limited to a spherical shape, and may be, for example, an arcuate shape which extends over the whole lateral length of the engagement piece portion  66 .