Electrical connector

An electrical connector is provided for detecting a terminal holder's projecting from a connector housing easily. The electrical connector includes a first connector housing, a second connector housing having a hood for receiving the first connector housing, and the terminal holder. The terminal holder is provided with an engagement groove which abuts on the hood when the first connector housing is engaged with the second connector housing by mistake. Consequently, it is possible to prevent the first connector housing having the terminal incompletely inserted therein from engaging with the second connector housing.

BACKGROUND OF THE INVENTION 
The present invention relates to an electrical connector with detecting 
means which, in case that one or more terminals are incompletely inserted 
into terminal accommodating chamber in an connector housing, prevents the 
connector housing from being engaged with another connector housing. 
In general, this kind of electrical connector comprises a male connector 
housing, a female connector housing for accommodating the male connector 
housing therein, and a terminal holder to be engaged in the male connector 
housing. 
In operation of the general electrical connector, the terminal holder is 
firstly inserted into an insertion hole formed in the male connector 
housing. Then, the inserted terminal holder is temporarily fixed in the 
male connector housing by an engagement of a temporary engagement 
projection formed on the terminal holder with a temporary engagement part 
formed on the male connector housing. Next, under the temporary engagement 
condition, normally, a plurality of female terminals are inserted into 
terminal accommodating chambers formed in the male connector housing and 
secured therein. Thereafter, the terminal holder is further depressed and 
formally engaged in the male connector housing by an engagement of a 
formal engagement projection of the terminal holder with a formal 
engagement part of the male connector housing. Subsequently, the male 
connector housing is engaged with the female connector housing, whereby 
the female terminals in the male connector housing can be electrically 
connected with the male terminals inserted into the female connector 
housing, finally. 
In the conventional connector, however, since the male connector housing 
includes a great number of terminal accommodating chambers into which the 
corresponding female terminals are to be inserted, there is a possibility 
that the female terminals completely and incompletely inserted into the 
terminal accommodating chambers exist together in the male connector 
housing. Then, due to a difficulty for a worker to distinguish respective 
conditions of the female terminals in the terminal accommodating chambers 
from the outside, if the terminal holder is depressed into the insertion 
hole by mistake, only one side of the terminal holder may be formally 
engaged in the male connector housing, depending on the position of the 
female terminal inserted imperfectly. Or again, the other side of the 
terminal holder may project from the insertion hole in spite that the 
terminal holder is accommodated in the insertion hole. Under such a 
condition, when the male connector housing is forcibly engaged with the 
female connector housing by mistake, the terminal holder is stuffed into 
the insertion hole by a hood projecting from the female connector housing, 
so that the male connector housing may be fitted into the female connector 
housing under an undesirable condition. 
SUMMARY OF THE INVENTION 
Under such a circumstance, it is therefore an object of the present 
invention to provide an electrical connector with detecting means which, 
in case that one or more terminals are inserted into one connector housing 
incompletely, allows a worker to detect a terminal holder's projecting 
from the connector housing with ease when engaging the connector housing 
with another connector housing to be mated with the former connector 
housing. 
The object of the present invention described above can be accomplished by 
an electrical connector comprising: 
a first connector housing having at least one terminal accommodating 
chamber formed therein for accommodating a terminal; 
a second connector housing having a hood for receiving the first connector 
housing; 
a terminal holder including a frame body with at least one insertion hole 
formed corresponding to the terminal accommodating chamber, the terminal 
holder being adapted so as to engage in the first connector housing 
temporarily and formally thereby to fix the terminal inserted into the 
terminal accommodating chamber; and 
detecting means for detecting the terminal holder's projecting from the 
first connector housing when the terminal is inserted into the terminal 
accommodating chamber incompletely. 
According to the above-mentioned arrangement, while the terminal holder is 
temporarily engaged in the first connector housing, the terminal is 
inserted into the terminal accommodating chamber. After insertion, the 
terminal holder is formally engaged in the first connector housing to fix 
the terminal in the terminal accommodating chamber. Therefore, if the 
terminal is inserted into the terminal accommodating chamber incompletely, 
the terminal holder will project from the first connector housing because 
the terminal holder is not engaged in the first connector housing 
formally. Consequently, even if a worker is eager to further engage the 
first connector housing with the second connector housing by mistake, such 
a projecting of the terminal holder from the first connector housing can 
be detected by the detecting means, whereby the first and second connector 
housings cannot engage with each other. 
On the contrary, if the terminal is inserted into the terminal 
accommodating chamber completely, the terminal holder does not project 
from the first connector housing since the terminal holder can be engaged 
in the first connector housing formally. Consequently, the first and 
second connector housings can engage with each other. 
In the present invention, preferably, the detecting means comprises an 
engagement groove which is formed on one sidewall of the frame body and 
adapted so as to abut on the hood when the first connector housing is 
engaged with the second connector housing. With this arrangement, when the 
first connector housing having the terminal holder imperfectly engaged 
therein is engaged with the second connector housing by mistake, the 
engagement groove comes into contact with the hood. Consequently, it is 
possible to prevent the first connector housing having the terminal 
incompletely inserted therein from engaging with the second connector 
housing. 
In the present invention, more preferably, the engagement groove has a 
slanted surface which is inclined from an edge of the sidewall toward a 
center of the insertion hole in the longitudinal direction. With this 
arrangement of the slanted surface, when the first connector housing is 
erroneously engaged with the second connector housing, the slanted of the 
engagement groove abuts on the hood. With this abutment, an external force 
in a direction opposite to a direction to insert the terminal holder into 
the first connector housing acts on the slanted surface, so that the 
terminal holder is drawn out of the first connector housing by the hood of 
the second connector housing. 
Or again, the detecting means may comprise a slanted projection which is 
formed on an end wall on an opening side of the hood of the second 
connector housing so as to project in a direction to engage the second 
connector housing with the first connector housing and which is formed so 
as to extend into the hood. With this arrangement of the slanted 
projection, when the first connector housing is erroneously engaged with 
the second connector housing, the slanted projection abuts on the frame 
body of the terminal holder. Consequently, also in this case, the 
provision of the slanted projection makes it possible to prevent the first 
connector housing having the terminal incompletely inserted therein from 
engaging with the second connector housing. 
In the above-mentioned arrangement, preferably, the slanted projection is 
formed so as to project toward the first connector housing which is being 
engaged with the second connector housing and includes a tapered surface 
facing toward the terminal holder which is being inserted into the first 
connector housing. In such a case, when the tapered surface of the slanted 
projection abuts on the frame body of the terminal holder, the frame body 
is prevented from entering into the hood due to the hood. Consequently, 
also in this case, it makes possible to prevent the first connector 
housing having the terminal incompletely inserted therein from engaging 
with the second connector housing. Note, although a clearance is produced 
between an inner wall of the hood of the second connector housing and an 
outer wall of the first connector housing engaged with the second 
connector housing, it is a matter of course that the above-mentioned 
slanted projection is formed so as to extend into the hood within limits 
of the clearance. 
In addition to the slanted projection of the above-mentioned arrangement, 
the detecting means may further comprise an engagement groove which is 
formed on the frame body to have a slanted surface and which is adapted so 
that, when the first connector housing is engaged with the second 
connector housing, the slanted surface abuts on the tapered surface. 
Similarly, when the first connector housing is erroneously engaged with 
the second connector housing, the slanted surface of the engagement groove 
abuts on the tapered surface of the slanted projection. Consequently, it 
is possible to prevent the frame body with the engagement groove from 
entering into the hood having the slanted projection. 
Note, through the above-mentioned arrangement, the first connector housing 
may be a male housing, while the second connector housing is a female 
connector housing for engagement with the male housing. 
These and other objects and features of the present invention will become 
more fully apparent from the following description and appended claims 
taken in conjunction with the accompany drawing.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Embodiments of the present invention will be described with reference to 
drawings. FIGS. 1 to 10 show an electrical connector in accordance with a 
first embodiment of the present invention. 
In FIG. 1, the electrical connector 1A includes a male connector housing 
10, a female connector housing 20, a terminal holder 30 to be inserted 
into the male connector housing 10 for temporary and formal engagement, 
and detecting means A for detecting the terminal holder 30 projected from 
the male connector housing 10. Note, in this specification, the male 
connector housing 10 and the female connector housing 20 will be referred 
to "the male housing 10" and "the female housing 20", respectively, 
hereinafter. 
As shown in FIGS. 3 to 7, the male housing 10 has a plurality of terminal 
accommodating chambers 12 formed inside a housing body 11 and an insertion 
hole 13 formed on a lower wall 11a of the housing body 11 to accept the 
terminal holder 30 therein. The insertion hole 13 is formed so as to 
extend across the terminal accommodating chambers 12. The housing body 11 
is provided, on a left sidewall 11b thereof, with an introduction port 13a 
for introducing into the insertion hole 13. Further formed on the left 
sidewall 11b through the intermediary of a tapered surface 14a is a 
temporary engagement hole 14 above which a formal engagement piece 15a is 
provided. Additionally, a guide groove 16 is formed to extend along the 
insertion hole 13. On the other hand, another formal engagement piece 15b 
is formed on a right sidewall 11c of the body 11. Reference numeral 19 
designates a slide member which serves the male housing 10 with the female 
housing 20 while allowing the former to be fitted to the latter. Note, the 
configuration of the male housing 10 is at the option of the application 
so long as it can engage with the terminal holder 30 temporarily and 
formally and have the female terminals 2a fixed therein. Again, there is 
not necessarily need to provide the slide member 19 in the male housing 
10. 
As shown in FIG. 8, the female housing 20 is provided, on a front wall 21a 
of a housing body 20, with a hood 22 for accommodating the male housing 
10. The female housing 20 has a plurality of terminal accommodating 
chambers (not shown) formed inside the housing body 21, for accommodating 
a plurality of male terminals 3 (see FIG. 1). The male terminals 3 
inserted into the terminal accommodating chambers are arranged so as to 
extend from the front wall 21a into the hood 22. Note, in a modification, 
a connector directly connected with an instrument may be adopted as the 
female housing 20. 
As shown in FIGS. 2 and 3, the holder 30 is constituted by a frame body 31 
in the form of a lattice, which includes insertion holes 33 corresponding 
to the terminal accommodating chambers 12 of the male housing 10, 
respectively. Further, the frame body 21 is provided, on a lower side of a 
front wall 31a thereof, with detecting means A described later. The frame 
body 21 has a guide rail 33a formed on an upper wall 31b and a guide 
projection 33b formed on a lower wall 31c. The guide rail 33a and the 
guide projection 33b are formed in parallel with each other. On a rear 
wall 31d of the frame body 31, a flexible temporary engagement projection 
34a is formed so as to extend in the same direction of the guide 
projection 33b. On the other hand, a streak of formal engagement 
projection 34b is provided on a right sidewall 31e of the frame body 31. 
Each insertion hole 32 has a terminal pusher 35 formed on a bottom wall 
32a, for engagement with the female terminal 2 inserted into the male 
housing 10. 
The above-mentioned detecting means A comprises an engagement groove 36 
which is formed on the lower side of the front wall 31a of the frame body 
31 so as to extend in the longitudinal direction of the body 31. The 
engagement groove 36 has a slanted surface 36a formed to extend from a 
lower edge 31a' of the front wall 31a toward respective centers of the 
insertion holes 32 in the longitudinal direction, i.e., obliquely upward. 
In this way, owing to the formation of the engagement groove 36 on the 
front wall 31a of the frame body 31, in case that the terminal holder 30 
projects from the insertion hole 13 and even if the male and female 
housings 10, 20 are mutually engaged with each other by mistake, the 
slanted surface 36a of the groove 36 can abut on the front wall 22a of the 
hood 22, as shown in FIG. 10. Consequently, without being accommodated in 
the hood 22, the male housing 10 is prevented from engaging with the 
female housing 20. 
We now describe how to detect a condition that one or more female terminals 
are incompletely inserted into the male housing 10 by using the detecting 
means A. 
First of all, as shown in FIGS. 2 and 3, when the terminal holder 30 is 
forced to the interior of the insertion hole 13 through the introduction 
port hole 13a (i.e. the direction of X), the guide rail 33a is conducted 
into the guide groove 16, while the guide projection 33b is slidably moved 
on the lower wall 11a of the housing body 11 along an opening 13b of the 
insertion hole 13. Then, the guide projection 33b is engaged in the guide 
hole 17 formed on the lower wall 11a and the temporary engagement 
projection 34a is guided by the tapered surface 14a and engaged in the 
temporary engagement hole 14, so that the terminal holder 30 is engaged in 
the male housing 10 temporarily. Under such a temporary engagement 
condition, the female terminals 2 are inserted into the terminal 
accommodating chambers 12 in the direction of Z. 
Hereat, since the great number of female terminals 2 are inserted into the 
great number of terminal accommodating chambers 12 of the male housing 10 
as shown in FIG. 1, there is a case where the female terminals 2b 
perfectly and imperfectly inserted into the terminal accommodating 
chambers 12 exist in confusion. However, due to a difficulty for a worker 
to distinguish such inserted conditions of the female terminals 2 in the 
terminal accommodating chambers 12 from the outside, the terminal holder 
30 will be depressed into the insertion hole 13 after inserting the female 
terminals 2. Consequently, depending on the position of the female 
terminal 2b incompletely inserted into the terminal accommodating chamber 
12, either one of the formal engagement projections 34b on both sides of 
the terminal holder 30 may engage with the formal engagement piece 15a (or 
15b) on the housing body 11, in other words, the only side 30a of the 
terminal holder 30 may be formally engaged with the male housing 10 or 
accommodated in the insertion hole 13 for some reason or other. Note, such 
a condition of the connector will be referred as "a condition M", 
hereinafter. 
Under the above condition M, as shown in FIG. 10, when the male housing 10 
is engaged with the female housing 20 by mistake, the tapered surface 36a 
of the engagement groove 36 abuts on the front wall 22a of the hood 22. 
With this abutment, an external force in an opposite direction of Y' to a 
direction to depress the holder 30 acts on the tapered surface 36a through 
the front wall 22a, so that the terminal holder 30 is drawn out in the 
direction of Y'. Consequently, the more it is desired to engage the male 
and female housings 10, 20 with each other, the more the terminal holder 
30 is drawn out, thereby making it possible for the worker to distinguish 
the holder 30 projecting from the insertion hole 13 visually. Accordingly, 
it is possible to detect such a condition that the female terminal 2 is 
inserted into the terminal accommodating chamber 12 of the male housing 10 
incompletely easily and certainly. 
Note, in case that the female terminal 2 is perfectly inserted into the 
terminal accommodating chamber 12 of the male housing 10, as shown in 
FIGS. 2 to 5, both sides 30a, 30b of the terminal holder 30 can be 
inserted into the insertion hole 13 by the respective engagement of the 
formal engagement projections 34b on both sides of the terminal holder 30 
inserted into the insertion hole 13 with the formal engagement pieces 15a, 
15b on both sides of the housing body 11, whereby the holder 30 does not 
project from the insertion hole 13. Note, this condition will be referred 
as "a condition N", hereinafter. 
Therefore, the male housing 10 can be accommodated in the hood 22 since the 
tapered surface 36a of the engagement groove 36 does not abut on the front 
wall 22a of the hood 22, so that a locking projection 18a formed on a 
locking arm 18 engages in a locking hole 22b formed in the hood 22. In 
this way, the male and female housings 10, 20 can be mutually fitted to 
each other, so that the female terminals 2 in the male housing 10 are 
electrically connected with the male terminals 3 in the female housing 20. 
Thereafter, in the direction of X, the slide member 19 is slid and fixed 
on the male housing 10 while allowing the fitting condition between the 
male housing 10 and the female housing 20 to be confirmed. 
FIGS. 11 to 13 show the second embodiment of the electrical connector with 
detecting means B. Note, in this embodiment, elements similar to those of 
the first embodiment are indicated with the same reference numerals, 
respectively and their overlapping descriptions are eliminated. 
In FIGS. 11 and 12, this detecting means B is constituted by slanted 
projections 23 each of which is formed on the front wall 22a on the side 
of an opening 22c of the hood 22 projecting from the housing body 21 and 
which projects in the direction of Z' opposite to the direction Z and 
extends into the hood 22. 
As shown in FIG. 13, it should be noted that, under the engaging condition 
of the male and female housings 10, 20, there exists a clearance .delta. 
between an inner wall 22d of the hood 22 and a peripheral wall 11d of the 
housing body 11. Thus, the slanted projections 23 are formed so as to 
extend into the hood 22 within the limits of the clearance .delta.. 
Further, the slanted projections 23 are arranged on both sides of the 
front wall 22a so as to oppose the terminal holder 30 at the engagement of 
the male and female housings 10, 20. Each projection 23 includes a tapered 
surface 23a extending to the direction of Z'. Note, it may be applicable 
to form the slanted surface 23 in the longitudinal direction of the front 
wall 22a continuously. 
In this way, owing to the formation of the slanted projections 23 with the 
tapered surfaces 23a on the front wall 22a of the hood 22, in case that 
the terminal holder 30 projects from the insertion hole 13 and even if the 
male and female housings 10, 20 are mutually engaged with each other by 
mistake, the tapered surfaces 23a of the slanted projections 23 abut on 
the frame body 31 of the holder 30, as shown in FIG. 14. Consequently, 
without being accommodated in the hood 22, the male housing 10 is 
prevented from engaging with the female housing 20. 
We now describe how to detect a condition that one or more female terminals 
are incompletely inserted into the male housing 10 by using the detecting 
means B. 
Under the above condition M, when the male housing 10 is engaged with the 
female housing 20 by mistake, the tapered surfaces 23a of the slanted 
projections 23 abut on the front wall 31a of the frame body 31. With this 
abutment, the front wall 31a of the frame body 31 begins to move along the 
tapered surfaces 23a to the direction of Y', so that the terminal holder 
30 is drawn out in the direction of Y'. Consequently, the more the worker 
is eager to engage the male and female housings 10, 20 with each other, 
the more the terminal holder 30 is drawn out, thereby making it possible 
for the worker to distinguish the holder 30 projecting from the insertion 
hole 13 visually. Accordingly, it is possible to easily and certainly 
detect the case where the female terminal 2 inserted into the terminal 
accommodating chamber 12 of the male housing 10 is on the incompletely 
inserted condition. 
It is noted that, under the condition N, the tapered surfaces 23a of the 
slanted projections 23 do not abut on the front wall 31a of the frame body 
31, so that the male housing 10 is accommodated in the hood 22, while the 
locking projection 18a of the locking arm 18 engages in the locking hole 
22b formed in the hood 22. In this way, the male and female housings 10, 
20 can be mutually fitted to each other, so that the female terminals 2 in 
the male housing 10 are electrically connected with the male terminals 3 
in the female housing 20. Thereafter, the slide member 19 of the male 
housing 10 is slid in the direction of X, whereby the engagement condition 
between the male housing 10 and the female housing 20 is stabilized. 
FIGS. 15 and 16 show the third embodiment of the electrical connector with 
detecting means C. Note, also in this embodiment, elements similar to 
those of the first and second embodiments are indicated with the same 
reference numerals, respectively and their overlapping descriptions are 
eliminated. 
In FIGS. 15 and 16, the detecting means C is composed of the 
above-mentioned detecting means A of the first embodiment and the 
detecting means B of the second embodiment. That is, the detecting means C 
comprises the engagement groove 36 (see FIG. 9) formed on the underside of 
the front wall 31a of the frame body 31 to extend in the longitudinal 
direction and the slanted projections 23 formed on the front wall 22a on 
the side of the opening 22c of the hood 22 so as to project in the 
direction of Z' and extends into the hood 22. 
As shown in FIG. 9, the engagement groove 36 is provided with the slanted 
surface 36a which directs obliquely upward from the lower edge 31a' of the 
front wall 31a. 
While, as shown in FIG. 12, the slanted projections 23 are arranged on both 
sides of the front wall 22a so as to oppose the terminal holder 30 at the 
engagement of the male and female housings 10, 20. Similarly, each of the 
projections 23 includes the tapered surface 23a extending to the direction 
of Z'. Note, it is preferable that an inclination angle of the slanted 
surface 36a is equal to that of each tapered surface 23a. 
In this way, since the engagement groove 36 having the slanted surface 36a 
is formed on the front wall 31a of the frame body 31 in the direction of Z 
while the slanted projections 23 having the tapered surfaces 23a are 
formed on the front wall 22a of the hood 22 in the direction of Z', in 
case that the terminal holder 30 projects from the insertion hole 13 and 
even if the male and female housings 10, 20 are mutually engaged with each 
other by mistake, the tapered surfaces 23a of the slanted projections 23 
come into contact with the slanted surface 36a of the engagement groove 
36. Consequently, without being accommodated in the hood 22, the male 
housing 10 is prevented from engaging with the female housing 20. 
We now describe how to detect a condition that one or more female terminals 
2 are incompletely inserted into the male housing 10 by using the 
detecting means C. 
Under the above condition M, when the male housing 10 is engaged with the 
female housing 20 by mistake, the slanted surface 36a of the engagement 
groove 36 abuts on the tapered surfaces 23a of the slanted projections 23. 
By the abutment, the terminal holder 30 begins to move along the tapered 
surfaces 23a to the direction of Y' and is drawn out in the same 
direction. Consequently, the more the worker is eager to engage the male 
housing 10 with the female housing 20, the more the terminal holder 30 is 
drawn out, thereby making it possible for the worker to distinguish the 
holder 30 projecting from the insertion hole 13 visually. 
Accordingly, it is possible to detect such a condition that the female 
terminal 2 is incompletely inserted into the terminal accommodating 
chamber 12 of the male housing 10, easily and certainly. In addition, if 
the inclination angle of the slanted surface 36a is equal to that of each 
tapered surface 23a, the surface 36a can stick to the tapered surfaces 
23a, whereby the engagement between the male and female housings 10, 20 is 
further prevented. 
Similarly, under the condition N, the slanted surface 36a of the engagement 
groove 36 do not abut on the tapered surfaces 23a of the slanted 
projections 23, so that the male housing 10 is accommodated in the hood 
22, while the locking projection 18a of the locking arm 18 engages in the 
locking hole 22b formed in the hood 22. In this way, the male and female 
housings 10, 20 can be mutually fitted to each other, so that the female 
terminals 2 in the male housing 10 are electrically connected with the 
male terminals 3 in the female housing 20. Thereafter, the slide member 19 
of the male housing 10 is slid in the direction of X, whereby the 
engagement condition between the male housing 10 and the female housing 20 
is stabilized. 
Therefore, by examining whether the holder 30 is projected by depressing 
the male housing 10 into the female housing 20, it is possible to 
distinguish whether the connector is under the condition of M or N, 
instantly. Thus, it is possible to carry out the fitting operation between 
the male housing 10 and the female housing 20 rapidly and precisely. 
In common with the above-mentioned embodiments, it will be understood that 
the electrical connector is constructed in a manner that, even if the 
terminal holder 30 inserted into the male housing 10 is not formally 
engaged at al, the terminal holder 30 does not project since one side of 
the holder 30 is inserted into the male housing 10. However, the present 
invention is applicable for a situation that the other side of the 
terminal holder 30 projects, of course. 
Finally, it will be understood by those skilled in the art that the 
foregoing description is related to some preferred embodiments of the 
disclosed electrical connector, and that various changes and modifications 
may be made to the present invention without departing from the spirit and 
scope thereof.