Connector

When a retainer is displaced into a provisionally-retained position, a slanting abutment surface of a retaining step is abutted against a rear edge of a main portion of a metal terminal disposed in a half-inserted position. Then, when the retainer is pushed, each projection is guided by a slanting portion of a guide groove, so that the retainer is displaced obliquely forwardly downwardly, and reaches a completely-retained position. During this displacement, a forwardly-acting pressing force is exerted on the metal terminal, so that the metal terminal is automatically pushed deeper into a proper inserted position.

BACKGROUND OF THE INVENTION 
This invention relates to a connector having the function of double 
retaining of metal terminals by a retainer, and more particularly to a 
connector having the function of urging half-inserted metal terminals into 
a proper fully-inserted position in accordance with the insertion of the 
retainer. 
There are known connectors having a double retaining function to be 
performed by a retainer. In such a connector as shown in FIG. 7, when a 
metal terminal c is inserted into a terminal receiving hole b in a housing 
a from a rear end thereof, an elastic retaining pawl d formed on an upper 
wall of the terminal receiving hole b is elastically deformed by this 
inserted metal terminal. Then, when the metal terminal reaches a 
fully-inserted position at the inner end of the terminal receiving hole, 
the retaining pawl d is received in a retaining recess e, formed in the 
upper surface of the metal terminal c, due to its own resilient restoring 
force, thereby effecting a first-stage retaining in a withdrawing 
direction. Then, when a retainer f, inserted into a provisionally-retained 
position from a lower side of the housing a in a manner to generally 
divide the housing, is pushed in a direction of an arrow to be retained in 
a completely-retained position, a retaining step a formed on the retainer 
f is received in a recess h formed in a lower surface of the metal 
terminal c, thereby effecting a second-stage retaining. 
In such a connector, the metal terminal c is inserted while elastically 
deforming the retaining pawl d, as described above, and therefore a 
considerable load is perceived halfway, and despite the fact that the 
metal terminal has not yet reached the fully-inserted position, the 
inserting operation is often stopped under a mistake of facts in a 
partially-inserted position as indicated in a broken line in FIG. 7. 
If such a situation is encountered, even when the retainer f is pushed, the 
retaining step q is abutted against the lower surface of the metal 
terminal c, so that the retainer can not be inserted. In this case, the 
operator becomes aware of the partially-inserted condition of the metal 
terminal c, and it is necessary for the operator to once retract the 
retainer f, to re-insert the metal terminal c into the fully-inserted 
position, and then to again push the retainer f. However, since many metal 
terminals c have been inserted, it is not easy to find the 
partially-inserted terminal among these terminals. And besides, such 
partially-inserted metal terminal is not always one, and in an extreme 
case, all of the metal terminals must be re-inserted, thus inviting a 
disadvantage that an extremely troublesome operation must be done. 
It is known from experiences that the metal terminal c is held in the 
partially-inserted condition mainly because the retaining step q of the 
retainer f interferes with an end edge of a main portion i. 
SUMMARY OF THE INVENTION 
The present invention has been made in view of the above problem, and an 
object of the invention is to correct a partially-inserted condition of a 
metal terminal, thereby enabling mating connectors to be easily fitted 
together. 
One object of the present invention has been achieved by a connector 
comprising a housing having terminal receiving holes each for receiving a 
metal terminal inserted from a rear end thereof; a retainer insertable 
into a retainer insertion groove which is formed in the housing in a 
manner to generally divide each of the terminal receiving holes, and is 
open to one side of the housing, the retainer having communication holes 
communicatable with the terminal receiving holes, respectively, and the 
retainer being adapted to be retained in a provisionally-retained position 
where each of the communication holes does not hinder the insertion and 
withdrawal of the metal terminal and in a completely-retained position 
where the retainer is engaged with the metal terminals in a manner to 
limit the withdrawal of the metal terminals; wherein guide grooves for 
guiding the insertion of the retainer are formed respectively in those 
surfaces of one of the housing and the retainer facing the other, whereas 
projections for being displaced respectively along the guide grooves are 
formed on the other; the retainer can be abutted against part of the metal 
terminal in the provisionally-retained position when the metal terminal is 
disposed in a partially-inserted position; and each of the guide grooves 
is so formed that during the time when the retainer is displaced from the 
provisionally-retained position to the completely-retained position, the 
retainer can push the metal terminals from the partially-inserted position 
into a fully-inserted position. 
When the retainer is inserted into the retainer insertion groove in the 
housing, the retainer reaches the provisionally-retained position, with 
the projections guided by and moved along the guide grooves, respectively. 
The metal terminals are inserted, and then when the retainer is further 
inserted, the retainer is displaced to the completely-retained position. 
If the metal terminal is disposed in a partially-inserted position during 
the displacement of the retainer from the provisionally-retained position, 
the retainer is abutted against part of the metal terminal, and pushes the 
metal terminal into a fully-inserted position during the displacement of 
the retainer into the completely-retained position, and also the retainer 
retains the metal terminals against withdrawal in this position. 
Advantageous effects of the present invention will be described. Even if 
the metal terminal is inadvertently disposed in a partially-inserted 
position, the metal terminal can be automatically pushed into the 
fully-inserted position in accordance with the displacement of the 
retainer from the provisionally-retained position into the 
completely-retained position. Thus, there is no need to re-insert the 
metal terminal, and therefore the efficiency of the operation can be 
enhanced greatly.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
One preferred embodiment of the present invention, in which the invention 
is applied to a male connector, will now be described with reference to 
FIGS. 1 to 5. 
In these Figures, a housing 1 includes a body 2 of a rectangular 
parallelepipedic shape, and twelve (12) terminal receiving holes 3 for 
respectively receiving male metal terminals 11 are formed through this 
body, and extend from a front side to a rear side of the housing, the 
terminal receiving holes 3 being arranged in three columns and four rows. 
A retainer insertion groove 6 for receiving a retainer 5 for retaining the 
metal terminals 11 in a double manner is formed in a generally central 
portion of an upper surface of the body 2 in a manner to divide each 
terminal receiving hole 3, and guide walls 7 are provided respectively on 
opposite (right and left) sides of this retainer insertion groove. 
Communication holes 9 equal in number to the terminal receiving holes 3 are 
formed through the retainer 5, and are communicatable with the terminal 
receiving holes 3, respectively. Formed respectively in opposite (right 
and left) sides of the retainer are downwardly-open fitting grooves 10 in 
which the guide walls 7 are adapted to be fitted, respectively. 
The retainer 5 is inserted into a predetermined position in the retainer 
insertion groove 6, with the two fitting grooves 10 fitted respectively on 
the guide walls 7, as shown in FIG. 3, and then the metal terminals 11 are 
respectively inserted into the terminal receiving holes 3, and are pushed 
to inner ends thereof, so that an elastic retaining pawl 12 (see FIG. 3) 
formed within each receiving hole 3 is received in a retaining recess 14 
formed in an upper surface of a main portion 13 of the metal terminal 11, 
thereby effecting a first-stage retaining in a withdrawing direction. When 
the retainer 5 is further pushed, a retaining step 16, formed on an upper 
wall of each communication hole 9, is received in a recess 17 formed 
adjacent to a rear end of the main portion 13, thereby effecting a 
second-stage retaining, as described above for the conventional 
construction. 
Next, the structure of the insertion portion of the retainer 5 of the 
present invention will now be described in detail. 
In this embodiment, the thickness of the retainer 5 is smaller by a 
predetermined dimension than the width of the retainer insertion groove 6. 
A generally vertically-extending guide groove 19 for guiding the insertion 
of the-retainer is formed in an outer surface of each of the guide walls 7 
formed respectively on the opposite (right and left) sides of the retainer 
insertion groove 6. As shown in FIG. 2, the guide groove 19 has an upper 
straight portion 20 and a lower straight portion 21 which are parallel to 
each other, and are offset relative to each other in a front-to-rear 
direction in such a manner that inner edges of the two straight portions 
are disposed in a common straight line. This configuration is achieved by 
a mold of a special design for forming the two straight portions 20 and 
21, and this will be described later in detail. The lower end of the upper 
straight portion 20 is connected to the upper end of the lower straight 
portion 21 by a slanting portion 22 slanting toward the front side. An 
auxiliary groove 23 of a greater depth is formed in the straight portion 
20, and is disposed centrally of the width thereof, and extends from the 
upper end thereof to the slanting portion 22. An auxiliary groove 24 of a 
greater depth is formed in the straight portion 21, and is disposed 
centrally of the width thereof, and extends from the lower end thereof to 
the slanting portion 22. Each of the grooves 23 and 24 has a semi-circular 
cross-section, and has the end formed into a semi-spherical shape. The 
lower end of the auxiliary groove 23 and the upper end of the auxiliary 
groove 24 are separated from each other, unlike the guide groove 19. 
On the other hand, a projection 26 of a parallelogrammic shape is formed on 
that surface of each of the right and left fitting grooves 10 of the 
retainer 5 facing that surface of the guide wall 7 having the guide groove 
19 formed therein, and the projection 26 is formed at a predetermined 
position, and can be intimately fitted in and slide along the straight 
portions 20 and 21 and the slanting portion 22 of the guide groove 19. 
Further, a projection 27 of a semi-spherical shape for fitting in the 
auxiliary groove 23, 24 is formed on the surface of the projection 26. 
With respect to the guide groove 19, the lower straight portion 21 is not 
always necessary in view of the function of this embodiment described 
later in detail, and also the auxiliary groove 24 may be replaced by a 
semi-spherical hole for receiving the projection 27 which hole is formed 
at the position where the upper end of the lower auxiliary groove 24 is 
disposed. Furthermore, it is not necessary that the inner edges of the two 
straight portions 20 and 21 should be disposed in a common straight line, 
and this configuration is adopted for the convenience of the formation of 
the guide groove 19 by molding. 
More specifically, for forming the guide groove 19 by molding, a pair of 
upper and lower slide cores x and y each having an inclined front end are 
used, as shown in FIG. 5, and the cores x and y serve to form the upper 
and lower straight portions 20 and 21, respectively, and also serve to 
form halves of the slanting portion 22, respectively. Merely by 
withdrawing the upper and lower cores x and y in directions of arrows, 
respectively, the upper and lower straight portions 20 and 21 and the 
slanting portion 22 are simultaneously formed by molding. Namely, the 
removal of a mold portion in a direction away from the front surface of 
the sheet of FIG. 5 is omitted, thereby reducing the manufacturing cost. 
The front edge of the retaining step 16, formed on the upper wall of each 
communication hole 9 in the retainer 5, is cut to form a slanting abutment 
surface 29 which allows a smooth pushing of the metal terminal 11. 
The operation of this embodiment will now be described mainly with 
reference to FIGS. 3 and 4. 
First, the retainer 5 is brought into registry with a rear portion of the 
retainer insertion groove 6, and is inserted thereinto. At this time, each 
projection 26 and each projection 27 of the retainer 5 are fitted 
respectively in the upper straight portion 20 of the guide groove 9 and 
the auxiliary groove 23 during the insertion, and the retainer is inserted 
straight downward while guided by these portions. When each projection 26 
and each projection 27 reach the lower ends of the upper straight portion 
20 and the auxiliary groove 23, respectively, a resistance is perceived, 
and the insertion operation is stopped once, so that the retainer 5 is 
stopped at a position slightly before a provisionally-retained position. 
In this condition, the metal terminals 11 are inserted into the terminal 
receiving holes 3 of the housing 1, respectively, as described above. 
Then, when the retainer 5 is further pushed, the projection 27 is 
disengaged from the lower end of the auxiliary groove 23, and is brought 
into contact with the bottom surface of the slanting portion 22 of the 
guide groove 19 as shown in FIG. 4A, and the projection 26 is guided along 
this slanting portion 22, so that the retainer 5 is slightly displaced 
obliquely forwardly downwardly to reach the provisionally-retained 
position. 
In this provisionally-retained position, the projection 27 is held in 
contact with the bottom surface of the guide groove 19, as described 
above, and therefore because of a frictional engagement between the two, 
for example, when transporting a provisionally-assembled structure 
comprising the housing 1, the retainer 5 and the metal terminals 11, the 
retainer 5 will not be easily disengaged, and also the retainer 5 will be 
effectively prevented from being accidentally displaced into a 
completely-retained position. 
If any of the metal terminals 11 has not yet reached the fully-inserted 
position, and hence is disposed in a partially-inserted position when the 
retainer 5 is displaced into the above provisionally-retained position, 
the slanting abutment surface 29 on the front edge of the retaining step 
16 of the retainer 5 is abutted against a rear edge of the main portion 13 
of the metal terminal 11 disposed adjacent to the recess 17, as shown in 
FIG. 4A. 
In this condition, when the retainer 5 is further pushed, the projection 26 
is guided by the remaining portion of the slanting portion 22, and the 
retainer 5 is further displaced obliquely forwardly downwardly, so that 
the retainer 5 is abutted at its lower surface against the bottom surface 
of the retainer insertion groove 6, and hence reaches the 
completely-retained position, thus stopping the displacement, as shown in 
FIG. 4B. At this time, the projection 27 is fitted in the upper end of the 
lower auxiliary groove 24, thereby retaining the retainer 5 against upward 
movement. 
During the time when the retainer 5 is displaced obliquely forwardly 
downwardly from the provisionally-retained position to the 
completely-retained position, the metal terminal 11 receives a 
forwardly-acting pressing force to be pushed into the fully-inserted 
position, so that the first-stage retaining by the elastic retaining pawl 
12 is effected, and also the retaining step 16 of the retainer 15 is 
fitted in the recess 17, thereby effecting the second-stage retaining. 
Thus, in this embodiment, even if the metal terminal 11 is inadvertently 
held in a partially-inserted position, the metal terminal can be 
automatically pushed into the fully-inserted position in accordance with 
the displacement of the retainer 5 from the provisionally-retained 
position to the completely-retained position, and therefore there is no 
need to re-insert the metal terminal 11. 
In the structure of this embodiment, by bringing each projection 27 of the 
retainer 5 into contact with the bottom surface of the slanting portion 22 
of the guide groove 19, the retainer 5 can be easily locked in the 
provisionally-retained position in such a manner that the retainer can not 
be displaced upwardly and downwardly. Also, by fitting the projection 27 
in the upper end of the lower auxiliary groove 24, the retainer can be 
held in the completely-locked position against upward movement. 
In order to confirm the direction of the retainer 5, forwardly 
downwardly-slanting surfaces 32 and 33, which are parallel to the slanting 
portion 22 of the guide groove 19, and can be mated with each other, may 
be formed on a lower surface of a projected portion 31 formed on the upper 
rear edge of the retainer 5 and the upper rear edge of the retainer 
insertion groove 6, respectively, in which case in addition to the fitting 
of the projection 26 in the slanting portion 22 of the guide groove 19, a 
relative sliding movement between the slanting surfaces 32 and 33 serves 
to guide the oblique displacement of the retainer 5. 
In the above embodiment, although the invention is applied to the male 
connector, the invention can be applied to a female connector, as shown in 
FIG. 6. In this case, similarly, a guide groove 19 and auxiliary grooves 
23 and 24 are formed in each of two guide walls 7 provided respectively at 
opposite sides of a retainer insertion groove 6 in a housing la, and a 
projection 26 and a projection 27 are formed on that surface of each 
fitting groove 10 of the retainer 5 facing the guide wall. With this 
arrangement, during the time when the retainer 5 is 10 displaced from a 
provisionally-retained position (FIG. 6A) to a completely-retained 
position (FIG. 6B), those metal terminals 11a disposed in a 
partially-inserted position can be pushed into a fully-inserted position, 
as described above. 
Of course, in either of the above connectors, the guide groove 19 and the 
auxiliary grooves 23 and 24 may be provided at each fitting groove 10 of 
the retainer whereas, the projection 26 and the projection 27 may be 
formed on that surface of the guide wall 7 of the retainer insertion 
groove 6 facing these grooves.