Electrical connector having electrical contacts provided with retention means

An electrical connector comprises a dielectric housing having a passageway extending therethrough and a latching aperture in communication with the passageway. An electrical contact is positioned in the passageway and includes a resilient latch member that has a free end disposed in the latching aperture to retain the contact in the passageway. A projection extends outwardly from the latch member for engagement with an inside surface of the housing so that when a force opposite to the direction of insertion of the contact into the housing is applied to the contact the free end of the latch member is prevented from projecting beyond the outside surface of the housing.

FIELD OF THE INVENTION 
This invention is related to an electrical connector having an electrical 
contact disposed in a dielectric housing, one end of the contact is 
connected to, for example, an end portion of an electrical wire, and the 
other end of which is electrically engageable with a matable electrical 
contact inside another dielectric housing. 
The contact includes a resilient latching member having a projection member 
that engages an inside surface of the housing thereby preventing the 
latching member from projecting beyond an outside surface of the housing. 
BACKGROUND OF THE INVENTION 
Prior art electrical connectors shown in FIGS. 6-8 comprise a connector 
housing 1 and a plurality of contacts 5, which are retained inside 
passageways 2 formed inside the housing 1. The contacts 5 include a 
receptacle portion 9 for electrical engagement with a pin, a connecting 
portion 7 to which the end of an electrical wire is connected and a clamp 
8 to clamp onto the wire. The contact assembly is composed of a plurality 
of the contacts 5 held in a row by carriers 6. FIG. 6 shows each of the 
contacts 5 of the contact assembly being partly inserted in the 
passageways 2 of the connector housing 1, and FIG. 7A is a cross-sectional 
view showing the connector, along the line VII--VII of FIG. 6. As shown in 
FIGS. 6 and 7A, at this stage, only the receptacle portion 9 of each 
contact 5 is inserted in the respective passageway 2, and the connecting 
portion 7 and clamp 8 are exposed outside the housing 1. At this time, the 
resilient latching member 10 formed on each contact 5 has its free end 
projecting inside the temporary holding aperture 4 and retains the contact 
5 at this position. 
In connecting the electrical wire A to the contact 5, the wire is 
press-fitted into slots of the connecting portion 7 so that an electrical 
wire is electrically connected with the connecting portion and retained 
therein. Next, the clamp 8 is bent over and around the insulation of wire 
A, and thus the wire A is securely retained in the contact 5 by this clamp 
8. Each contact 5 is then completely inserted inside its respective 
passageway 2 as shown in FIG. 7B whereafter carriers 6 are removed. At 
this time, the free end of the resilient latching member 10 projects 
inside a latching aperture 3 formed in the housing 1 and engages with the 
housing 1, retaining the contacts 5 in position in housing 1. The 
assembled connector is matable with a complementary electrical connector 
so that the pins thereof inserted through the insertion apertures 1a 
formed at the front face of the housing 1 engage with the receptacle 
portions 9 of the contacts 5, and accordingly, electrically connect both 
connectors. 
When using the above-mentioned connector, a pulling force may be applied to 
the wire A connected to the contact 5, and a problem arises in that the 
resilient latching member 10 may be bent by this pulling force and 
projected outward from the latching aperture 3. 
In view of this problem, a connector having a contact as shown in FIG. 8 
has been proposed. The connector 1 includes the contact 5 with a latching 
member 10 having bifurcated end portions, one end portion 10a extending 
into the latching aperture 3, and the other end portion 10b being disposed 
inside the passageway 2. Thus, the contact 5 is firmly retained in the 
passageway by the engagement of the end portions 10a and 10b with the 
housing when a pulling force is exerted on the wire connected to the 
contact 5. Also, the end portion 10a of latching member 10 is prevented 
from projecting beyond the outside surface of the housing when subjected 
to a certain amount of pulling force. However, when the wire is subjected 
to a strong pulling force, the end portion 10a cannot be prevented from 
projecting further outward from the outside surface of the housing because 
of the bending of the end portions. Moreover, in order to bifurcate the 
tip of the latching member, the latching member must be made wider and 
both bifurcated end portions must be provided with a specified strength. 
Therefore, when the contact is inserted in the passageway, a stronger 
insertion force is required to deform the latching member, and thus a 
problem arises in that a stronger force is required to insert the contact. 
Also, since the bending of the bifurcated portions must be precise, a 
problem arises in that the control of the bending may cause difficulties 
during manufacturing. 
SUMMARY OF THE INVENTION 
In consideration of the above-mentioned problems, the object of this 
invention is to provide a contact having a resilient latching member which 
will retain the contact in the housing without projecting outward when a 
strong pulling force is exerted on the contact through a wire, and which 
will require less force to insert the contact in the housing. 
The electrical connector of the present invention comprises a dielectric 
housing having a passageway extending therethrough and a latching aperture 
in communication with the passageway. An electrical contact is positioned 
in the passageway and includes a resilient latch member that has a free 
end disposed in the latching aperture to retain the contact in the 
passageway. A projection extends outwardly from the latch member for 
engagement with an inside surface of the housing so that when a force 
opposite to the direction of insertion of the contact into the housing is 
applied to the contact the free end of the latch member is prevented from 
projecting beyond the outside surface of the housing.

DETAILED DESCRIPTION OF THE INVENTION 
The following is a detailed description of the preferred embodiment of the 
present invention, with reference to the accompanying drawings. 
FIGS. 1-4 show connector 20 which comprises a connector housing 21 and a 
plurality of electrical contacts 25 which are retained in passageways 22 
formed in the housing 21. Each contact 25 includes receptacle portion 29, 
connecting portion 27 to which the end portion of an electrical wire is 
connected, and clamp 28 which clamps onto the wire when connected. The 
contact assembly is composed of a plurality of contacts 25 retained in a 
row by carriers 26. FIG. 1 shows the contact assembly which is partly 
inserted in the housing. In FIGS. 1 and 2, only the receptacle portion 29 
of each contact 25 is inserted in the passageway 22, and the connecting 
portion 27 and clamp 28 are exposed outside. At this time, the free end of 
resilient latching member 30 formed on each contact 25, is disposed within 
temporary holding aperture 24, thereby retaining the contacts 25 at this 
position. Further, a projection 31, which is an integral part of the 
latching member 30 and bent at a right angle to the latching member 30, is 
formed at the side portion of resilient latching member 30. Projection 31 
is disposed within the passageway 22. 
In connecting wires A to contacts 25, the wires are press-fitted into slots 
of the connecting portions 27 so that the wires are electrically connected 
with the connecting portions and retained therein. Next, the clamps 28 are 
bent over and around the wires A, so that the wires A are firmly retained 
in the contacts 25 by the clamps 28. Then, as shown in FIG. 3, the 
contacts 25 are completely inserted inside the passageways 22. At this 
time, the free ends of resilient latching members 30 project into the 
latching apertures 23 formed in the housing 21, and accordingly, the 
contacts 25 are retained in the housing passageways. Furthermore, at this 
time, the projections 31 are disposed inside the passageways and engage 
with the inside walls of the passageways 22. 
When the connector 20 mates with a complementary connector and the pins 
thereof engage with the receptacle portions 29 of the contacts 25, an 
electrical connection between both connectors is realized. Moreover, at 
this time, a projection 41 of a latching arm 40 formed at the bottom 
surface of the housing 21 engages with the housing of the complementary 
connector thereby retaining both housings in the mated condition. 
Next, the case where a pulling force is exerted in a direction opposite to 
the insertion direction of the contacts upon the wires A is considered 
with reference to FIG. 4. If tension is applied to the wire in FIG. 4, the 
free end of resilient latching member 30 may project outward from the 
latching aperture 24. However, the projection 31 counteracts the tension 
by engaging with the inside surface of the housing 21, therefore, the free 
end of resilient latching 30 is prevented from projecting outward beyond 
the outside surface of the housing. 
Also, as shown in FIG. 5, the width W of the resilient latching member 30 
can be the same as that of the resilient latching member 10 of the 
conventional connector shown in FIGS. 7A and 7B. Accordingly, the width of 
the portion 30a where the elastic deformation is created at the time of 
inserting the contact is reduced, and therefore, less force is needed to 
insert the contacts into the cavity. Furthermore, even if the angle 
.alpha. at which the resilient latching member 30 is bent upward is larger 
than usual as shown in FIG. 4, no problem will arise because the free end 
of the resilient latching member 30 is prevented from being projected 
outward from the latching aperture by the projection 31 engaging the 
inside surface of the housing. Therefore, an advantage is obtained whereby 
the bending of the resilient latching lance is simplified. 
As disclosed above, according to this invention, because the projection is 
formed integrally with the resilient latching member, which is inserted in 
and engaged with the housing, the free end of the resilient latching 
member is prevented from projecting outward even when a pulling force is 
exerted on the contact in a direction opposite to the insertion direction. 
Further, the width of the resilient latching member can be kept small, and 
thus only a small force is needed to insert the contact into the housing.