Connector locking connection detection device

In a connector, a locking connection detection member is beforehand attached to a rear portion of a male connector housing and is retained thereto by resilient retaining pieces of the locking connection detection member in such a manner that the locking connection detection member is extended rearwardly from the male connector housing. Engagement release projections for the resilient retaining pieces are provided on the female connector housing so that when the male and female connector housing are completely connected together with the lock arm engaged with the engagement portion, the engagement release projections release the retaining of the resilient retaining piece, thereby enabling the removal of the locking connection detection member. According to this arrangement, a complete connection of a connector can be detected easily.

BACKGROUND OF THE INVENTION 
This invention relates generally to a connector for connecting a wire 
harness for an automotive vehicle, and more particularly to a device for 
detecting a locking connection between a pair of connectors. 
FIGS. 1 and 2 show a conventional connector. 
In FIG. 1, a flexible lock arm c of the cantilever type is formed on a 
surface of a male connector housing a, and is extended forwardly. An 
engagement hole d for a retaining portion cl of the flexible lock arm c is 
formed in a female connector housing b. 
In the above construction, when the male and female connector housings a 
and b are to be connected together, the retaining portion cl of the 
flexible lock arm c is abutted against a front end of an engagement frame 
portion dl of the female connector housing b, and is displaced downward, 
and then the retaining portion cl is received in the engagement hole d, 
and is restored to its initial form to thereby complete the locking 
connection, thus providing a completely locked condition. 
In this condition, an unlock prevention piece e is fitted on the flexible 
lock arm c to partially fill in a gap f between the flexible lock arm c 
and the surface of the male connector housing a, thereby preventing a 
subsequent displacement of the flexible lock arm c to prevent the 
unlocking (FIG. 2). 
In an incompletely locked condition in which the retaining portion cl is 
not engaged in the engagement hole d, the flexible lock arm c is kept 
displaced downward with the gap f reduced, and therefore it is impossible 
to connect the unlock prevention piece e to the flexible lock arm c. With 
this arrangement, the incomplete connection between the pair of connector 
housings is detected (Japanese Utility Model Publication No. Sho. 
59-29351). 
In the above conventional art, the unlock prevention piece e, having the 
function of detecting the incomplete connection, must be attached to the 
flexible lock arm c when the pair of connector housings are connected 
together, and therefore extra labor is required for the detection, and 
besides this is cumbersome from the viewpoint of the management of the 
parts. 
SUMMARY OF THE INVENTION 
With this problem in view, it is an object of this invention to provide a 
construction by which a complete connection of a connector can be detected 
easily. 
The above object has been achieved by a connector locking connection 
detection device comprising: a male connector housing having a flexible 
lock arm; a female connector housing having an engagement portion for the 
flexible lock arm; a locking connection detection member to be attached to 
a rear portion of the male connector housing in advance of mating the male 
and female connector housings; resilient retaining pieces for retaining 
the locking connection detection member to the rear portion of the male 
connector housing in such a manner that the locking connection detection 
member is extended rearwardly from the male connector housing; and 
engagement release projections for the resilient retaining pieces, 
provided on the female connector housing; wherein when the male and female 
connector housings are completely connected together with the lock arm 
engaged with the engagement portion, the engagement release projections 
release the retaining of the resilient retaining pieces, thereby enabling 
the removal of the locking connection detection member. 
The locking connection detection member may include an incomplete 
connection detection retaining portion with which the flexible lock arm is 
engaged when the male and female connector housings are mated together but 
the lock arm is not engaged with the engagement portion. 
The resilient retaining pieces may be provided on the locking connection 
detection member, or otherwise, may be provided in the male connector 
housing. 
In the former case, it is preferable that the locking connection detection 
member includes stopper projections, each of the resilient retaining 
pieces is formed with a first retaining projection at a predetermined 
position apart from the stopper projections and the male connector housing 
includes second retaining projections at the reat end thereof so that each 
of the second retaining projections is interposed between the stopper 
projections and the first retaining projection to retain the locking 
connection detection member to the rear portion of the male connector 
housing. 
In the latter case, it is preferable that the resilient retaining pieces 
are provided within receiving chambers passing through the male connector 
housing from its front end to its rear end thereof, the locking connection 
detection member includes forwardly-directed retaining pieces so that the 
forwardly-directed retaining pieces are engaged with the resilient 
retaining pieces within the receiving chambers for retaining the locking 
connection detection member to the rear portion of the male connector 
housing. 
Terminal retaining chambers not retaining terminals and terminal retaining 
pieces in the terminal retaining chambers not retaining terminals may be 
used as the receiving chambers and the resilient retaining pieces, 
respectively.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
FIGS. 3 to 5B show a connector having a connector locking connection 
detection device according to an embodiment of the present invention. 
In FIG. 3, reference character A denotes a male connector housing, 
reference character B a female connector housing, and reference character 
C a locking connection detection member. These are made of a synthetic 
resin. 
The male connector housing A has a groove 1 formed in its upper surface 
thereof and extending from its front to its rear end, and a flexible lock 
arm 2 which is received in the groove 1 and is extended rearwardly via its 
upstanding proximal portion 2a. This flexible lock arm has a lock 
projection 2b intermediate the opposite ends thereof, and an operating 
portion 2c at the rear end thereof. Retaining projections 3 for the 
locking connection detection member C are formed respectively on the right 
and left side surfaces of the male connector housing A at the rear end 
thereof, and are directed right and left, respectively. 
An engagement portion 5 for the lock projection 2b is notched in a sleeve 
portion 4 of the female connector housing B, and engagement release 
projections 6 are formed respectively on the right and left portions of 
the front end of the sleeve portion 4. The engagement release projections 
are directed forwardly, and have respective sharp tip edges 6a and 
respective tapered drive surfaces 6b directed right and left, 
respectively. 
The locking connection detection member C is of a U-shape defined by a top 
plate portion 7 and a pair of side plate portions 8 and 8 extending from 
the opposite ends of the top plate portion 7. Each of the two side plate 
portions 8 has a resilient retaining piece 9 formed at the front end 
portion thereof as a result of the provision of slits 8a, the resilient 
retaining piece 9 having a retaining projection 9a. The retaining 
projection 9a has a tapered driven surface 9b at its inner side. Stopper 
projections 10 are formed on the inner surface of each side plate portion 
8 in spaced relation to the retaining projection 9a. 
In the above construction, the locking connection detection member C is 
beforehand connected to the male connector housing A and is extended 
rearwardly therefrom in such a manner that the retaining projections 9a of 
the resilient retaining pieces 9 are engaged respectively with the 
retaining projections 3 (FIG. 4A). 
In this condition, when the male connector housing A is fitted into the 
female connector housing B by holding the locking connection detection 
member C, the lock projection 2b is abutted against the front end of the 
sleeve portion 4, and the flexible lock arm 2 is displaced downward, and 
at the same time the engagement release projections 6 are abutted 
respectively against the retaining projections 9a of the resilient 
retaining pieces 9 (FIGS. 4B and 5A). When the male connector housing A is 
completely fitted in the female connector housing B, the flexible lock arm 
2 is restored to its initial form, so that the lock projection 2b is 
engaged in the engagement portion 5, and metal terminals (not shown) 
contained in the two connector housings are connected together. At the 
same time, the tapered drive surfaces 6b of the engagement release 
projections 6 respectively displace the resilient retaining pieces 9 
outwardly through the tapered driven drive surfaces 9b in such a manner 
that the retaining projections 9a are disengaged from the retaining 
projections 3, respectively (FIGS. 4C and 5B). In this condition, the 
locking connection detection member C is removed, thereby detecting the 
complete connection between the pair of connectors (FIG. 4D). 
In an embodiment shown in FIGS. 6 to 9D, in addition to the above 
construction, an engagement plate portion 11 for receiving the operating 
portion 2c of the flexible lock arm 2 of the male connector housing A in a 
manner to allow displacement thereof is provided on the inner side of a 
top plate portion 7 of a locking connection detection member C'. 
Incomplete connection detection retaining portions 12 for engagement with 
projections 2c.sub.1 provided respectively on the opposite sides of the 
operating portion 2c are formed on the engagement plate portion 11. 
In this case, the locking connection detection member C' is connected to 
the male connector housing A as shown in FIG. 9A, and in this condition 
the operating portion 2c of the flexible lock arm 2 is not engaged with 
the incomplete connection detection retaining portions 12. 
In the condition in which the male connector housing A is incompletely 
fitted in the female connector housing B, the flexible lock arm 2 is 
displaced downward, and therefore the projections 2c.sub.1 of the 
operating portion 2c are engaged with the incomplete connection detection 
retaining portions 12, thereby preventing the locking connection detection 
member C' from being disengaged from the male connector housing A (FIG. 
9B). 
When the male connector housing A and the female connector housing B are 
completely connected together, the flexible lock arm 2 is restored to its 
initial form, and the lock projection 2b is engaged in the engagement 
portion 5. As a result, the engagement between the operating portion 2c 
and the incomplete connection detection retaining portions 12 is released 
(FIG. 9C), and as described above, each engagement release projection 6 
releases the engagement between the resilient retaining piece 9 and the 
retaining projection 3, and therefore the locking connection detection 
piece C' can be detached from the male connector housing A (FIG. 9D). 
In an embodiment shown in FIGS. 10 to 13D, a resilient retaining piece 13a 
is provided within each of receiving chambers 13. Terminal receiving 
chambers 13' for retaining terminals and the receiving chambers 13 for 
receiving retaining pieces (later described) of the locking connection 
detection member C", extend through the male connector housing from its 
front to its rear end. Engagement release projections 16 are provided 
within the sleeve portion 4 and are directed forwardly. Each of the 
engagement release projection 16 has a sharp edge 16a at its front end, 
and a tapered drive surface 16b directed downwardly. Forwardly-directed 
retaining pieces 19 each having an engagement hole 19a are formed 
respectively on the inner surfaces of the side plate portions 8. 
In the above construction, the locking connection detection member C" is 
beforehand connected to the male connector housing A' and is extended 
rearwardly therefrom in such a manner that the retaining pieces 19 are 
received respectively in the receiving chambers 13 of the male connector 
housing A', with retaining projections 13a.sub.1 of the resilient 
retaining pieces 13a received respectively in the engagement holes 19a 
(FIGS. 12A and 13A). 
In this condition, when the male connector housing A' is fitted into the 
female connector housing B' by holding the locking connection detection 
member C", the lock projection 2b is abutted against the front end of the 
sleeve portion 4, and the flexible lock arm 2 is displaced downward. At 
the same time the projections 2c.sub.1 of the operating portion 2c are 
engaged respectively with the incomplete connection detection retaining 
portions 12, and also the tapered drive surfaces 16b of the engagement 
release projections 16 are abutted respectively against tapered driven 
surfaces 13a.sub.2 of the resilient retaining pieces 13a (FIGS. 12B and 
13B). When the male connector housing A' is completely fitted in the 
female connector housing B', the flexible lock arm 2 is restored to its 
initial form, and as a result the engagement between the operating portion 
2c and the incomplete connection detection retaining portions 12 is 
released, and also the lock projection 2b is engaged in the engagement 
portion 5. At this time, the tapered drive surfaces 16b of the engagement 
release projections 16 respectively displace the resilient retaining 
pieces 13a through the tapered driven drive surfaces 13a.sub.2 in such a 
manner that the retaining projections 13a.sub.1 are disengaged from the 
retaining holes 19a of the retaining pieces 19, respectively (FIGS. 12C 
and 13C). In this condition, the locking connection detection member C" is 
removed, thereby detecting the complete connection between the pair of 
connectors (FIG. 13D). 
As described above, the present invention provides the connector locking 
connection detection device comprising the male connector housing having 
the flexible lock arm, and the female connector housing having the 
retaining portion for the flexible lock arm; wherein the locking 
connection detection member is beforehand attached to the rear portion of 
the male connector housing and is retained thereto by the resilient 
retaining means in such a manner that the locking connection detection 
member is extended rearwardly from the male connector housing; the 
engagement release projections for the resilient retaining means are 
provided on the female connector housing; and when the male and female 
connector housing are completely connected together with the lock arm 
engaged with the engagement portion, the engagement release projections 
release the retaining of the resilient retaining means, thereby enabling 
the removal of the locking connection detection member. Therefore, by 
removing the locking connection detection member, the complete connection 
of the connector can be confirmed easily and rapidly, and the removed 
locking connection detection member can be again used for attachment to 
another connector housing. 
Further, since the locking connection detection member is attached to the 
male connector housing in such a manner that the detection is extended 
rearwardly from the male connector housing, the male connector housing can 
be fitted into the female connector housing while holding the locking 
connection detection member with an operator's hand when the male and 
female connector housings are to be connected together, and therefore the 
connecting operation is facilitated.