Electrical connector

An electrical connector can be fitted with either an electric wire cover (40) or a component installation cover (30), the choice of cover corresponding to the presence or absence of an electrical component (39) in the corresponding connector housing. The electric wire cover (40) or the component installation cover (30) are installed detachably and, as a result, the relatively expensive connector housing (10) is provided with shared components which can be adapted to the intended use.

TECHNICAL FIELD 
The present invention relates to an electrical connector. 
BACKGROUND TO THE INVENTION 
An air bag circuit of an automobile contains male and female connector 
housings which mutually fit together, either one of the male or female of 
these connector housings containing ferrite for the purpose of noise 
reduction. In the usual case, the fitting portions of the male and female 
connectors have the same specification. However, there is a possibility 
that the specifications are not the same, depending on whether the ferrite 
is housed in the male or female connector housing. In these circumstances, 
when the male connector and the female connector, having differing 
production patterns, are fitted together, two types of connector housings 
are produced, those which are able to contain ferrite and those which are 
not, in order to correspond to the presence or absence of ferrite in the 
corresponding connector housing. By this means one can avoid the waste of 
having ferrite within both the male and female connectors, or the problem 
of having ferrite in neither the male or female connector. 
In general, the shape of connector housings is complicated due to the fact 
that they must house terminal fittings, and consequently moulding cost are 
relatively high. Moreover, in the case of conventional connectors, in the 
case where the connector is adapted to the corresponding connector which 
does or does not contain ferrite, two types of connector housings must be 
produced, one for containing ferrite and the other not. Consequently, 
there is the problem that production costs rise, and confusion may be 
possible due to the number of different mouldings. The present invention 
has been developed after taking the above problem into consideration, and 
aims to present a connector housing in which the connectors have common 
features, and in which costs are reduced. 
SUMMARY OF THE INVENTION 
According to the invention, there is provided an electrical connector 
comprising a housing, an electrical terminal in the housing, and an 
electrical wire joined to said terminal, said housing having a wire 
guiding portion defining an aperture through which the wire is guided from 
the interior of the housing to the exterior thereof, said guiding portion 
being adapted externally to receive one of several tubular covers for said 
wire, each of said covers having one end internally adapted to said 
guiding portion, and said covers having a different internal volume to 
accommodate or not accommodate an auxiliary component. 
Such a connector is adapted to receive a cover chosen according to the 
presence or absence of an auxiliary component, such as a cylinder of 
ferrite material. In this way the relatively expensive connector housing 
is common, and several relatively inexpensive covers can adapt this 
connector housing to a desired installation requirement. 
Preferably the covers comprise half-shells adapted to be connected about 
the protruding wire, this facilitating assembly and inspection. In the 
preferred embodiment the half-shells of each respective cover are 
symmetrical and identical; this reduces the number of possible components 
still further.

DESCRIPTION OF PREFERRED EMBODIMENT 
The housing 10 comprises a housing main body 11, a female terminal fitting 
20, a retainer 26, a short-circuit cancelling member 24 and a fitting 
detecting member 25. A fitting member 12 protrudes downwards from the 
housing main body 11 and fits within a hood of a corresponding connector 
housing (not shown). A terminal housing chamber 13 which houses the female 
terminal fitting 20 is formed within the housing main body 11, this 
terminal housing chamber 13 comprising an upper space 13A which is open on 
its upper face, and a lower space 13B which joins at a right angle with 
the fitting member 12 from the anterior edge of the upper space 13A. 
The female terminal fitting 20 is L-shaped and comprises a box-like 
terminal connecting member 21 which connects with male tabs (not shown) of 
the corresponding connector housing, and an electric wire connecting 
member 22 which crimps an electric wire 23. The terminal connecting member 
21 is housed within the lower space 13B and the electric wire connecting 
member 22 is housed within the upper space 13A. After the female terminal 
fitting 20 has been housed, it is maintained in the correct attached state 
by the retainer 26 which is installed within the housing main body 11. 
A detailed explanation is omitted, but when the short-circuit cancelling 
member 24 is installed in the correct position of the housing main body 11 
during a fitted state with the corresponding connector housing, this 
short-circuit cancelling member 24 cancels the short-circuit of the male 
tabs (not shown) of the corresponding connector housing. Furthermore, the 
fitting detecting member 25 installed within the housing main body 11 
detects whether the corresponding connector housing has been installed 
correctly. 
At the posterior end of the housing main body 11, the open face of the 
upper space 13A is covered by a covering plate 15 which is supported on 
the housing main body 11 via a hinge 14, and the posterior end portion of 
the housing main body 11 forms an electric wire guiding member 16. An 
electric wire guiding hole 16A is open in the posterior end face of the 
electric wire guiding member 16, this electric wire guiding hole 16A 
joining with the upper space 13A and guiding the electric wire 23. Either 
the component installation cover 30 or the electric wire cover 40 can be 
installed on the electric wire guiding member 16. 
The electric wire guiding member 16 is described in detail next. A pair of 
installation grooves 17 are formed on the left and right outer side faces 
of the electric wire guiding member 16, these installation grooves 17 
being located slightly to the anterior of the posterior end face and being 
formed by cutting away in an up-down direction. Moreover, stoppers 18 are 
also formed on the left and right outer side faces of the electric wire 
guiding member 16 at a location posterior to the installation grooves 17, 
the upper and lower ends of each stopper 18 being cut away in a stepped 
shape, as illustrated. Further, in size and in form, the electric wire 
guiding member 16 is symmetrical above and below and to the left and 
right. 
Next, the component installation cover 30 and the electric wire cover 40 
are explained. 
The component installation cover 30 comprises a pair of semitubular members 
31 which are identical in shape and which join together to form a tubular 
shape. The anterior end portions of the semitubular members 31 form 
installation members 32 which join with the electric wire guiding member 
16. A pair of hook members 33 protrude from the left and right edges of 
the installation members 32 and form a U-shape when seen from above (from 
the outer face). The anterior ends of the hook members 33 fit with the 
installation grooves 17 of the electric wire guiding member 16. Further, 
stopping members 34 located at approximately the innermost side of the 
U-shape of the hook members 33 project inwards and fit together with the 
stoppers 18. The installation members 32 fit together from above with the 
upper half of the electric wire guiding member 16 and from below with the 
lower half of the electric wire guiding member 16. Furthermore, the height 
of the installation members 32 is one half that of the electric wire 
guiding member 16 and so, when installed, the upper and lower faces of the 
installation members 32 and the hook members 33 form a single face with 
the upper and lower faces of the electric wire guiding member 16. In this 
way, the left and right of the installation members 32 are symmetrical 
with the electric wire guiding member 16. 
Along the length in an anterior-posterior direction of each semitubular 
member 31, and adjoining the installation member 32, the inner face of the 
semitubular member 31 forms a semitubular shape having a semicircular 
circumference face. The posterior end of the interior of this semitubular 
portion has a plurality of protruding bands 35A extending along the inner 
circumferential face in the direction of the circumference, these forming 
an electric wire supporting member 35. A resilient protective layer 27 
which surrounds the electric wire 23 fits with this electric wire 
supporting member 35, the protruding bands 35A pressing into the external 
face of the protective layer 27 and thus regulating its movement relative 
to the electric wire supporting member 35. Moreover, the portion extending 
between the electric wire supporting member 35 and the installation member 
32 comprises a component housing member 36. The component housing member 
36 houses tubular-shaped ferrite 39 which is known for its function in 
reducing noise after the electric wire 23 has been inserted. The 
dimensions of the ferrite 39 are such that its external diameter is close 
to the internal diameter of the component housing member 36. 
Furthermore, the semitubular members 31 are provided with a stopping means 
to maintain them in a joined state. That is, stopping protrusions 37 are 
formed on the left exterior side face of the installation member 32 and 
the left exterior side face of the electric wire supporting member 35, and 
resilient stopping members 38, formed on the right exterior side face of 
the installation member 32 and the right exterior side face of the 
electric wire supporting member 35, extend along these faces and protrude 
towards the corresponding semitubular member 31. Each resilient stopping 
member 38 is provided with a stopping groove 38A which fits with the 
stopping protrusion 37 of the corresponding semitubular members 31 when 
these are in a joined state, the stopping groove 38A thereby maintaining 
the joined state of the semitubular members 31. 
The electric wire cover 40 is made from a pair of semitubular members 41, 
each semitubular member 41 being identical in shape and comprising an 
installation member 32, an electric wire supporting member 35, a stopping 
protrusion 37 and a resilient stopping member 38. These installation 
members 32, electric wire supporting members 35, stopping protrusions 37, 
and resilient stopping members 38 are identical in shape with the 
installation members 32, electric wire supporting members 35, stopping 
protrusions 37 and resilient stopping members 38 of the component 
installation cover 30 mentioned above. That is, the electric wire cover 40 
lacks the component housing member 36 of the component installation cover 
30, and the anterior-posterior dimensions of the electric wire cover 40 
are correspondingly shorter. Consequently, identical configuration and 
parts have been assigned the same numbers as those of the component 
installation cover 30, and a detailed explanation of the electric wire 
cover 40 is omitted. 
Next, the operation of the present embodiment are explained. In the case 
where ferrite used for noise reduction is not provided within a 
corresponding connector housing, noise reduction is carried out by 
installing the ferrite 39 and the component installation cover 30 within 
the housing 10. When the component installation cover 30 is to be 
installed, the ferrite 39 and the protective layer 27 are first positioned 
so as to encase the electric wire 23, and the pair of semitubular members 
31 of the component installation cover 30 join together from above and 
below so as to surround the ferrite 39 and the protective layer 27. 
At this juncture, the hook members 33 of the installation members 32 fit 
together with the installation grooves 17, and the stopping members 34 are 
stopped by the stoppers 18. When the semitubular members 31 are fitted 
together, the stopping grooves 38A of the resilient stopping members 38 
engage the stopping protrusions 37, thereby locking the component 
installation cover 30 in a joined state and fixing it within the housing 
10. 
In this installed state, the stopping of the hook members 33 by the 
installation grooves 17 regulates the movement of the component 
installation cover 30 in an anterior-posterior direction and a left-right 
direction relative to the housing 10. Further, the stopping of the 
stopping members 34 by the stoppers 18 regulates the movement of the 
component installation cover 30 in an up-down direction relative to the 
housing 10. Moreover, the ferrite 39 is housed within the component 
housing member 36 and, within the electric wire supporting member 35 the 
protruding bands 35A press into the external face of the protective layer 
27, thereby regulating its movement in an anterior-posterior direction and 
providing protection for the electric wire at a distance from the housing 
10. 
When the component installation cover 30 is to be removed from the housing 
10 the resilient stopping members 38 are bent outwards and become 
separated from the stopping protrusions 37, and the two semitubular 
members 31 can be separated into their upper and lower halves. 
Further, in the case where ferrite is provided within the corresponding 
connector housing, there is no need to provide the ferrite 39 within the 
housing 10 and, consequently, the electric wire cover 40 is installed on 
the housing 10. Installation and removal of the electric wire cover 40 is 
carried out in the same manner as for the component installation cover 30 
described above, and therefore a detailed description thereof is omitted. 
In the installed state, the stopping of the hook members 33 by the 
installation grooves 17 regulates the movement of the electric wire cover 
40 in an anterior-posterior direction and a left-right direction, and the 
stopping of the stopping members 34 by the stoppers 18 regulates the 
movement of the electric wire cover 40 in an up-down direction. Moreover, 
within the electric wire supporting member 35, the protruding bands 35A 
press into the external face of the protective layer 27 and thus regulate 
its movement in an anterior-posterior direction at a distance from the 
housing 10. 
In the conventional case, the housing 10 is complicated in shape and 
moulding costs are relatively high. The present embodiment presents two 
kinds of covers, the electric wire cover 40 and the component installation 
cover 30, these being simple in shape and having relatively low moulding 
costs. They correspond to the presence or absence of ferrite in the 
corresponding connector housing and enable costs to be reduced. 
Furthermore, when the component installation cover 30 or the electric wire 
cover 40 is to be installed on the housing 10, the pair of semitubular 
members 31 or 41 can be joined together to enclose the electric wire 23 
and the ferrite 39, or to enclose only the electric wire 23. Consequently, 
compared to the case in which the electric wire is inserted through a 
cylindrical cover, operability is improved. 
Moreover, the pairs of semitubular members 31 and 41 which join together 
have an identical form and are symmetrical along their anterior-posterior 
axis. Consequently, compared to the case in which both semitubular members 
have differing configurations, there is a lesser number of components, and 
costs are reduced. Further, unlike the case in which differing semitubular 
members have to be joined together, the time-consuming process of 
correctly fitting together the semitubular members 31 and 41 is 
eliminated, and operability is thus improved. 
The present invention is not limited to the embodiments described above 
with the aid of figures. For example, the embodiments described below also 
lie within the technical range of the present invention. In addition, the 
present invention may be embodied in various other ways without deviating 
from the scope thereof. 
In the embodiment described above, both the electric wire cover and the 
component installation cover comprise a pair of semitubular members which 
join together symmetrically along an axial direction to form an identical 
shape. However, according to the present invention, either or both of the 
covers may equally well comprise asymmetrical semitubular members. 
In the embodiment described above, either the electric wire cover or the 
component installation cover is attached to or detached from one female 
connector. However, according to the present invention, this may equally 
well be one male connector, or both male and female connectors. In the 
case where the covers are to be attached to or detached from both male and 
female connectors, the cover of the male or female side may have a common 
shape, and therefore only three types of components will be needed. 
The above embodiment explains a case suitable for a connector provided with 
a fitting detecting function and a short-circuit cancelling function. 
However, the present invention can also be suitable for different 
connectors as well. 
The above embodiment explains a case suitable for using noise-reducing 
ferrite as the electric wire installation component. However, the cover 40 
is also suitable for housing materials other than ferrite.