Abstract:
The connector housing of the present invention is a connector housing that fits together with a mating connector housing, comprising a housing cover member having a circular cross section, a first anti-rotation member detachably disposed around the outer periphery of the housing cover member, and a second anti-rotation member formed in a concave shape in the face of the housing cover member across from the mating connector.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to a connector housing and to an electrical connector that makes use of the same, and more particularly relates to an electrical connector for connecting a lead to the squib of an automotive airbag device.  
       BACKGROUND  
       [0002]     The electrical connectors used to make electrical connections in various kinds of devices need to be small enough and have the appropriate shape as dictated by each application. For instance, an airbag that deploys in the event of an automotive collision in order to protect the occupants is not needed under normal conditions, and is therefore housed in a small space such as the steering column. An electrical connector called a squib connector, which is used to connect the lead wires supplying current to the electrical igniter (squib) of the inflator on the basis of an ignition signal from an electronic control unit (ECU), needs to be small and low in height so that such limited spaces can be effectively utilized.  
         [0003]      FIG. 11  is an oblique view of an example of a conventional squib connector disclosed in Japanese Laid-Open Patent Application 2000-294343. This squib connector  50  is configured such that a pair of lead wires W for supplying ignition current from the electrical system of a vehicle to a squib are connected at the upper end of a housing cover member  51  at a right angle to the direction in which the connector is fitted, and the lower end of the housing cover member  51  is inserted into a connector (not shown) on the squib side. The upper part of the housing cover member  51  is provided with a housing component  52  that houses a ferrite core (not shown) for absorbing noise that could result in a malfunction of the airbag device. The housing cover member  51 , which serves as the main part of the squib connector  50 , is substantially cylindrical in form, so protrusions  51   a  corresponding to concave components in the connector on the squib side are provided so as to restrict rotation so that relative rotation will be impossible once the squib connector  50  has been inserted into the squib-side connector. Also, locking tabs  51   d  that latch locking grooves on the squib-side connector are provided so that the squib connector  50  will not fall out of the squib-side connector.  
         [0004]     The most suitable electrical connector is selected for each device in which the connector is to be used, which creates a problem in that many different kinds of connector housings of correspondingly different shapes have to be available. Naturally, standardization is underway in certain applications, but up to now the shape of the locking means for preserving a fitted state or of the anti-rotation means provided to a connector whose housing cover member has a circular cross section has been determined individually according to the connector on the side of the device to which the first connector is to be fitted.  
       SUMMARY  
       [0005]     The present invention was conceived in light of this situation, and it is an object thereof, among others, to provide an interchangeable connector housing and connector that can be inserted into a plurality of types of connector housing having differently shaped housing cover members.  
         [0006]     The connector housing of the present invention is a connector housing that fits together with a mating connector housing, comprising a housing cover member having a circular cross section, a first anti-rotation member detachably disposed around the outer periphery of the housing cover member, and a second anti-rotation member formed in a concave shape in the face of the housing cover member across from the mating connector.  
         [0007]     With the connector housing of the present invention, a first anti-rotation member is detachably disposed around the outer periphery of a housing cover member having a circular cross section, and a second anti-rotation member is formed in a concave shape in the face of the housing cover member across from the mating connector, which means that interchangeability can be maintained no matter what kind of anti-rotation means the mating connector housing is equipped with.  
         [0008]     An alternate electrical connector of the present invention comprises a housing cover member having a circular cross section and in which a contact is housed, a first anti-rotation member detachably disposed around the outer periphery of the housing cover member, and a second anti-rotation member formed in a concave shape in the face of the housing cover member across from the mating connector, which means that interchangeability can be maintained no matter what kind of anti-rotation means the mating connector housing is equipped with.  
         [0009]     Specifically, with the present invention, when the housing on the mating connector side is designed such that anti-rotation is accomplished by a concave component provided around the outer periphery of the housing cover member, an anti-rotation member having a corresponding convex shape is mounted on the outer periphery of the housing cover member in order to accomplish anti-rotation. When the housing on the mating connector side is designed such that anti-rotation is accomplished by a convex component formed on a face across from the housing cover member, a dummy member having no convex component is mounted instead of the above-mentioned anti-rotation member having a convex component, which allows insertion and also accomplishes anti-rotation. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]     The invention will now be described with reference the accompanying figures of which:  
         [0011]      FIG. 1  is an oblique view of the external appearance of a squib connector that is a preferred embodiment of an electrical connector constituted using the connector housing pertaining to the present invention;  
         [0012]      FIG. 2  is an exploded oblique view of a state in which the anti-rotation member has been removed from the housing cover member of the squib connector in  FIG. 1 ;  
         [0013]      FIG. 3  illustrates an example of the squib-side connector, in which  FIG. 3A  is an oblique view including a cross section,  FIG. 3B  is a view of the fitting face from the squib connector side, and  FIG. 3C  is a cross section along the A-A line in  FIG. 3B ;  
         [0014]      FIG. 4  illustrates another example of the squib-side connector, in which  FIG. 4A  is an oblique view including a cross section,  FIG. 4B  is a view of the fitting face from the squib connector side, and  FIG. 4C  is a cross section along the B-B line in  FIG. 4B ;  
         [0015]      FIG. 5  is an oblique view of the shape of the dummy member attached to the anti-rotation member attachment component of the housing cover member instead of an anti-rotation member;  
         [0016]      FIG. 6  is a diagram of the shape of the locking tab in a conventional squib connector;  
         [0017]      FIG. 7  is a diagram of the shape of the locking tab in the squib connector of an embodiment of the present invention;  
         [0018]      FIG. 8  is a partial oblique view illustrating a state in which the locking tab of the squib connector in an embodiment of the present invention is latched to a locking groove with a V-shaped cross section of the squib-side connector;  
         [0019]      FIG. 9  is a partial oblique view illustrating a state in which the locking tab of the squib connector in an embodiment of the present invention is latched to a locking groove with a rectangular cross section of the squib-side connector;  
         [0020]      FIG. 10  is an exploded oblique view of the squib connector in a preferred embodiment of the electrical connector in which the connector housing pertaining to the present invention is used; and  
         [0021]      FIG. 11  is an oblique view of an aspect of a conventional squib connector. 
     
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS  
       [0022]     An embodiment of the present invention will now be described in greater detail through reference to the drawings. Those components that are the same in the various drawings are numbered the same. For the sake of ease of description, the up and down and left and right directions in the drawings will be referred to in exactly that way.  
         [0023]     Referring to  FIG. 1 , a squib connector  300  is used to connect a pair of lead wires W for supplying ignition current from a vehicle power supply to the electrical igniter (squib) of an inflator that deploys an airbag in the event of a collision of the vehicle.  
         [0024]     The housing of the squib connector  300  consists of a housing cover member  110 , which serves as the main portion of the housing, and a housing cover  120 . The ends of the pair of lead wires W connected to the electrical system of the vehicle are guided from the lower part of the housing cover member  110  at a right angle to the insertion direction of the connector, and are press-fitted to one end of a pair of contacts (not shown) housed in the housing cover member  110 . The other end of these contacts is disposed so as to be located in a pair of contact holes  111  provided to a T-shaped concave portion  110   t  in the upper face of the housing cover member  110 , and when the upper part of the housing cover member  110  is inserted into the connector on the squib side, a pair of contact pins (not shown) fit therein so as to form an electrical connection therebetween.  
         [0025]     The housing cover  120  is attached at one end to the lower part of the housing cover member  110  via a hinge  115 , allowing the other end to be opened and closed. When the pair of contacts press-fitted to the pair of lead wires W is housed in the connector housing cover member  110 , fixing tabs  120   f  provided at the end of this housing cover  120  that is on the opposite side from the hinge  115  are fitted into fixing holes  110   f  in the housing cover member  110 , so that the pair of lead wires W is held sandwiched at wire receiving sections  110   g  (see  FIG. 10 ) in the housing cover member  110 .  
         [0026]     Since the housing cover member  110  and the squib-side connector both have circular cross sections, the squib connector  300  is able to rotate when mated with the squib-side connector. Accordingly, if there is no restriction whatsoever on relative rotation between the two, there is the danger of damage to the pair of contacts of the squib connector  300  and to the pair of contact pins of the squib-side connector that are fitted thereto. To prevent this, the squib connector  300  is equipped with an anti-rotation member  130 . The anti-rotation member  130  is provided with a convex component  130   a  that protrudes in the radial direction from the housing cover member  110 , and this is fitted into a concave component provided at a specific location of the squib-side connector, which restricts the squib connector  300  so that it cannot rotate when inserted in the squib-side connector. This anti-rotation member  130  is designed to be detachable from the outside of the housing cover member  110 , and its shape can be selected as dictated by the type of anti-rotation means provided to the squib-side connector.  
         [0027]     The squib connector  300  is also equipped with locking tabs  110   d  at two places on the outside of the housing  110 , for keeping the squib connector  300  from falling out of the squib-side connector once inserted. As will be discussed below, the shape of these locking members  110   d  allows a locking regardless of the shape of the locking grooves provided to the squib-side connector.  
         [0028]      FIG. 2  is an exploded oblique view of a state in which the anti-rotation member  130  has been removed from the housing cover member  110 . The anti-rotation member  130  is mounted by being pushed into the outer face of the housing cover member  110 . Fixing components are provided at three places on an anti-rotation member attachment component  110   a  of the housing cover member  110 , and the anti-rotation member  130  is fixed by these so that it will not come out readily. Protrusions  130   b  provided on both sides at the top end of the anti-rotation member  130  fit into grooves  10   b  provided on both sides at the entrance side of the attachment component  110   a . A protrusion  130   c  (see  FIG. 10 ) provided in the middle of the lower end of the anti-rotation member  130  fits into a concavity  10   c  provided in the butting face of the attachment component  110   a.    
         [0029]      FIG. 3  illustrates an example of the squib-side connector into which the squib connector  300  is inserted. This squib-side connector  400  comprises a cylindrical housing  410  and a pair of contact pins  411  disposed at the bottom of this housing. The pair of contact pins  411  provided at the bottom of the housing  410  are connected to the squib of an inflator by passing through an insulating base  410   e  that supports these pins. The insulating base  410   e  is formed as a substantially T-shaped convex component inside the housing  410 . This T-shaped convex component fits into the T-shaped concave portion  110   t  ( FIGS. 1 and 2 ) formed at the distal end face of the housing cover member  110  of the squib connector  300  that is inserted into the housing  410 . As a result, relative rotation between the squib-side connector  400  and the squib connector  300  inserted therein is restricted, and this also prevents the pair of contact pins  411  from being incorrectly connected to the pair of lead wires W.  
         [0030]     A dummy member  140  having no convex component as shown in  FIG. 5  is attachable instead of the anti-rotation member  130  having the convex component  130   a  to the anti-rotation member attachment component  10   a  of the housing cover member  110  of the squib connector  300  that is inserted into the squib-side connector  400 . As a result, even if the squib connector  300  is inserted into a housing  410  in which no concave component for restricting the rotation of the squib connector  300  has been formed at the entrance edge of the housing cover member, insertion down to the required depth will not be hindered by interference of the convex component  130   a  of the anti-rotation member  130 .  
         [0031]     Referring to  FIG. 8 , a locking groove  410   d  that is substantially V-shaped in cross section is provided all the way around the inner face of the housing  410 . Once the squib connector  300  has been inserted down to the required depth in the housing  410 , the distal ends of the locking tabs  110   d  provided at two places on the outside of the housing cover member  110  spread out within the locking groove  410   d  and catch the upper edge thereof, which keeps the squib connector  300  from slipping out of the squib-side connector  400 .  
         [0032]      FIG. 4  illustrates another example of the squib-side connector into which the squib connector  300  is inserted. This squib-side connector  500  is similar to the above-mentioned squib-side connector  400  in that it comprises a cylindrical housing  510  and a pair of contact pins  511  disposed at the bottom of this housing, but differs in that semicircular concavities  510   a  are formed at the entrance to the housing  510 . These semicircular concavities  510   a  are disposed asymmetrically at two places around the inner peripheral edge of the housing  510 , and at least one of them is fitted to the semicircular convex component  130   a  provided on the outside of the squib connector  300 , which restricts the rotation of the squib connector  300  and also prevents the pair of contact pins  511  from being incorrectly connected to the pair of lead wires W.  
         [0033]     The squib-side connector  500  is also similar to the squib-side connector  400  in that a locking groove  510   d  is provided all the way around the inner face of the cylindrical housing  510 , but differs in that the cross sectional shape of this groove is rectangular. Once the squib connector  300  has been inserted down to the required depth in the housing  510 , the distal ends of the locking members  110   d  provided at two places on the outside of the housing cover member  110  spread out within the locking groove  510   d  and catch the upper edge thereof, which keeps the squib connector  300  from slipping out of the squib-side connector  500 .  
         [0034]     The locking groove provided to the inner face of the housing of the squib-side connector can have any of several different cross sectional shapes, such as the V-shape shown in  FIG. 3  or the rectangular shape shown in  FIG. 4 . For example, for a squib-side connector having a V-shaped locking groove as shown in  FIG. 3 , a squib connector having locking tabs  110   j  of a simple shape as shown in  FIG. 6  has been used. However, when a conventional squib connector having locking tabs with a simple shape such as this is inserted into a squib-side connector having a locking groove with a rectangular cross section, no locking function will be exhibited because the locking tabs will not completely catch the locking groove. Therefore, until now a number of different types of squib connector had to be made available according to the types of squib-side connector.  
         [0035]      FIG. 7  shows the shape of the locking member provided on the outside of the housing cover member  110  of the squib connector  300  in an embodiment of the present invention. This locking member  110   d  is provided at two places on the outside of the housing cover member  110 . Once the housing cover member  110  has been inserted down to the required depth in the squib-side connector, the tapered locking members  110   d  spread out within the locking groove by their own elasticity, and their distal ends interfere with the upper edge of the locking groove, which keeps the squib connector  300  in the squib-side connector.  
         [0036]      FIG. 8  shows a state in which the locking tabs  110   d  of the squib connector  300  have been latched to the locking groove  410   d  with a V-shaped cross section of the squib-side connector. Specifically, the locking tabs  110   d , which comprise elastic members that spread outward in a tapering form from the outside of the housing cover member  110 , are able to spread out along the wall face of the locking groove  410   d  having a V-shaped cross section. Once spread out, these ends catch the upper edge of the locking groove and thereby restrict the squib connector  300  from slipping out of the squib-side connector, so a locking function is exhibited.  
         [0037]      FIG. 9  shows a state in which the locking tabs  110   d  of the squib connector  300  have been latched to the locking groove  410   d  with a rectangular cross section of the squib-side connector. The locking tabs  110   j  of a conventional squib connector spread outward in a tapering form immediately from the outside of the housing cover member  110 , such that there have been cases where they could not fit in a locking groove with a rectangular cross section. In such cases, the locking tabs  110   j  could not effectively lock the connector because their expanded ends did not catch the upper edge of the locking groove  510   d . In contrast, the locking tabs  110   d  do not immediately spread out from the outside of the housing cover member  110 , and instead spread out in a tapering form after first rising along the outside. Specifically, the portion that spreads out in a tapering form is shorter in height than with the conventional configuration, and when inserted in a squib-side connector having a locking groove with a rectangular cross section, the portions that have spread out in this tapering form are accommodated in the locking groove. Thus, the squib connector  300  can be inserted into any of a number of types of squib-side connector whose locking grooves have different cross sectional shapes.  
         [0038]     Referring to the embodiment in  FIG. 10 , contacts  210  that are press-fitted to the pair of lead wires W are held in the housing  110  by fitting notches  210   h  of the contacts  210  into latching components  110   h  of the housing cover member  110 . The above-mentioned pair of lead wires W guided to wire receiving sections  110   g  of the housing cover member  110  is sandwiched by the housing cover  120 . Receptacles  211  are provided on the ends of the contacts  210  on the opposite side from the lead wires W, and are housed in receptacle housing sections  110   e  of the housing cover member  110 , pass through the contact holes  111 , and are fitted to the pair of contact pins  511  of the squib-side contact  500 . A ferrite material  230  used for absorbing noise is disposed around the receptacles  211 .  
         [0039]     In the above description, the example was of a case in which an electrical connector was formed using the connector housing pertaining to the present invention, but embodiments of the present invention are not limited to this, nor are applications of the electrical connector limited to a squib connector.