Shielded electric connector and wire connecting method

A shielded electric connector comprises contact pins each of which includes a contact portion for coming into contact with a mating contact piece, on one end thereof and a joint portion for connecting an electric wire to be connected, on the other end side thereof, an insulating housing in which the contact pins are disposed and held, a shield hood member which includes a front envelope that encloses the contact pins disposed and held in the insulating housing and a rear envelope that is so formed as to be continuous to and unitary with the front envelope, that is open on only one side and that is formed with an electric wire lead-out portion, a shield lid member adapted to be coupled to the shield hood member in a manner to close the opening of the shield hood member, and a shield connection part adapted to be connected to a shield layer of the electric wires. A method of connecting electric wires to such shielded electric connector is also disclosed.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a shielded electric connector which 
reduces radio-frequency and electromagnetic interferences, and a wire 
connecting method therefor. 
2. Description of the Prior Art 
Heretofore, in an electric connector for use in computer equipment, by way 
of example, noise has entered an electronic signal transmitted by an 
electric cable or the like, due to a radio frequency or any other 
electromagnetic wave carried in the air, and the computer equipment or the 
like has experienced interference. Accordingly, it has been necessary to 
take a measure against such electromagnetic interferences. An electric 
connector with such a countermeasure has hitherto been disclosed in the 
official gazette of Japanese Patent Application Laid-Open No. 27480/1984. 
The prior-art shielded electric connector is a shielded electric connector 
comprising a connector shell of metal material which is coupled to an 
insulating terminal block for supporting terminals electrically connected 
to conductors of shielded cable that includes a cable having a plurality 
of coated conductors, an outer insulating jacket enclosing the conductors, 
and a shield layer interposed between the conductors and the jacket, the 
conductors and the shield layers being extended from an end of the 
insulating jacket. It comprises a pair of metallic shield members which 
are opposingly arranged between the connector shell and the insulating 
jacket, means to couple the opposingly-arranged shield members to each 
other, means to electrically connect the shield members to the connector 
shell, and an outer insulating shell of unitary structure which encloses 
the shield members, a part of the connector shell and a part of the 
insulating jacket. 
Since the conductors of the cable and the terminals connected with the 
conductors are substantially completely enclosed with the pair of shield 
members opposingly arranged, such a prior-art shielded electric connector 
has the advantage that it can be shielded from electromagnetic waves. 
The prior-art shielded electric connector as stated above, however, has the 
following problems: 
(1) The shield members and the connector shell are constructed by separate 
elements, and the means for connecting them is soldering, brazing, metal 
spray, welding, mechanical clamping means, or an electrically-conductive 
binder. Therefore, the assemblage is laborious, the cost is high, and mass 
production is impossible. 
(2) Also means for connecting the shield members and the shield layer is 
soldering, metal spray, mechanical clamping, welding, bonding means, or 
the like. Therefore, the assemblage is very difficult, the cost is high, 
and mass production is impossible. 
(3) Since the shield members and the connector shell are constructed by 
separate elements, the number of components increases accordingly, and the 
number of steps for assemblage increases, too. 
An object of the present invention is to provide a shielded electric 
connector and a wire connecting method therefor which can solve the 
problems of the prior art as mentioned above. 
SUMMARY OF THE INVENTION 
According to an aspect of this invention, there is provided a shielded 
electric connector comprising contact pins each of which includes a 
contact portion for coming into contact with a mating contact piece, on 
one end side thereof and a joint portion for connecting an electric wire 
to be connected, on the other end side thereof, an insulating housing in 
which the contact pins are disposed and held, a shield hood member which 
includes a front envelope that encloses the contact pins disposed and held 
in the insulating housing and a rear envelope that is so formed as to be 
continuous to and unitary with the front envelope, that is open on only 
one side and that is formed with an electric wire lead-out portion, a 
shield lid member adapted to be coupled to the shield hood member in a 
manner to close the opening of the shield hood member, and a shield 
connection means adapted to be connected to a shield layer of the electric 
wires. 
According to an another aspect of this invention, there is provided a 
method of connecting electric wires to a shielded electric connector of a 
type as described above, comprising the steps of connecting terminal end 
parts of the electric wire to be connected, to the joint portions of the 
corresponding contact pins disposed in the insulating housing, placing the 
insulating housing on a front end part of the shield lid member and 
connecting the shield connection portion of the shield lid member to the 
shield layer of the electric wires, and thereafter installing the 
insulating housing in the shield hood member so as to enclose the contact 
portions of the contact pins with the front envelope of the shield hood 
member and coupling the shield lid member to the shield hood member so as 
to close the opening of the shield hood member and to lead out the 
electric wires from the electric wire lead-out portion of the shield hood 
member. 
This invention will now be described in further detail with regard to 
preferred embodiments as illustrated in the accompanying drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring now to FIG. 1, there is shown a shielded electric connector 10 
according to an embodiment of this invention. The connector 10 comprises 
principally contact pins 11, an insulating housing 20, a shield lid member 
30, a shield hood member 40, an insulating hood 50, buttons 70, and 
engagement fixtures 80. 
The contact pin 11 may be one usually used in an electric connector of this 
type, and is formed of an electrically-conductive metal material. On one 
end side, it has a contact portion 11A which comes into contact with the 
contact piece of a mating connector, while on the other end side, it has a 
joint portion (not appearing in the figures) which serves to electrically 
connect the electric wire 61 of a cable 60. 
The insulating housing 20 is unitarily molded of a plastics material, and 
it has the plurality of contact pins 11 disposed and held therein in such 
a manner that the contact portions 11A are protruded from the front end 
thereof. 
As clearly shown in FIGS. 3A, 3B and 3C, the shield lid member 30 is formed 
by punching and bending a springy metal material, in such a manner that a 
flat portion 31 for placing the insulating housing 20 thereon is provided 
at the front part of this member 30 (the left part as seen in FIG. 3A), 
while a shield connection portion 32 being substantially in the shape of 
the letter U is protrusively provided at the rear end part of this member. 
The shield lid member 30 is formed with engaging arms 34 which protrude 
sideward of this member in the same direction as that of the shield 
connection portion 32 at positions intermediate between the flat portion 
31 and the shield connection portion 32 and each of which has an opening 
34' that engages the protrusion 43' of the outer wall of the shield hood 
member 40 to be explained later. 
As clearly shown in FIGS. 4A, 4B, 4C and 4D, the shield hood member 40 is 
unitarily molded of a metal material by, for example, die casting, in a 
manner to include a front envelope 41 which envelops the contact portions 
11A of the contact pins 11 disposed in the insulating housing 20 and which 
is formed at the front part of this member 40 (the left part as seen in 
FIG. 4B), as well as a rear envelope which is formed rearward of the front 
envelope 41 so as to be continuous thereto and unitary therewith. The rear 
envelope is made up of an enveloping flat portion 45 including first side 
surfaces 42, second side surfaces 43 and shoulder side surfaces 44 which 
are set upright at the peripheral edges of the member 40. Accordingly, 
this rear envelope is open in only one side surface (an upper surface in 
FIG. 4D). In addition, a U-shaped groove 46 is provided in the rear part 
of the enveloping flat portion 45, the groove receiving the shield 
connection portion 32 of the shield lid member 30 which is pressedly fixed 
to the shield layer 62 of the cable 60. This U-shaped groove 46 constructs 
an electric wire lead-out portion for leading out the cable 60 rearwards. 
On the inner surface of the front envelope 41, a plurality of ribs 41' for 
ensuring a firmer shield connection with the metal shell of the mating 
connector are circumferentially provided. Besides, the first side surfaces 
42' and second side surfaces 43 are respectively provided with protrusions 
42' and 43' which fulfill functions to be described later. 
As clearly shown in FIGS. 5A and 5B, this insulating hood 50 is unitarily 
molded of a plastic material, in a manner to include a hollow 51 which 
accommodates the shield lid member 30 and shield hood member 40 unitarily 
assembled as will be stated later, and a fin 52 which has a through hole 
53 for causing the cable 60 to penetrate it. On both the sides of the 
hollow 51, there are provided engagement fixture receiving portions 54 for 
accommodating the engagement fixtures 80, and button receiving portions 55 
for accommodating the buttons 70. The button receiving portion 55 is 
formed with a recess 56 for exposing the antiskid corrugation 71 of the 
button 70. On the other hand, the engagement fixture receiving portion 54 
is defined between an inner side wall 57 and an outer side wall 58, and a 
pair of engagement projections 57' fulfilling a function to be stated 
later are provided on the inner side wall 57, while a pair of stopper lugs 
58' fulfilling a function to be stated later are provided on the inner 
side of the outer side wall 58. As clearly shown in FIG. 5B, the 
engagement projection 57' is provided with a tapered portion 57". 
As clearly shown in FIGS. 6A, 6B and 6C, the button 70 is molded of a 
plastics material, and it is provided with the antiskid corrugation 71 
which protrudes from the recess 56 of the insulating hood 50 and which 
serves to depress the hook 81 of the engagement fixture 80 with a finger, 
and a fixation groove 72 which serves to receive and fix the button 
mounting portion 82 of the engagement fixture 80 on the opposite side to 
the antiskid corrugation 71. 
As clearly shown in FIGS. 7A and 7B, the engagement fixture 80 is formed of 
a springy metal material by punching and bending, in such a manner that 
the hooked engagement portion 81 is provided at the extreme end of this 
fixture, while the button mounting portion 82 is formed on the other end 
side. Springy or elastic pieces 83 are provided on both the sides of the 
engagement fixture 80 substantially in the middle thereof. As clearly 
shown in FIG. 7B, each elastic piece 83 is formed with a first 
coming-off-preventive bend 83A, a second coming-off-preventive bend 83B 
and a stabilizer bend 83C which fulfill functions to be described later. 
Next, there will be described the procedural steps by which the shielded 
electric connector of such construction is assembled, and the wires of the 
cable are joined. 
(1) First, the cover of a cable 60 is peeled off to expose wires 61. 
Besides, the terminal parts of the individual wires 61 are jointed by 
soldering, crimp contact, pressure welding or the like to the joint 
portions of contact pins 11 which are disposed and held in an insulating 
housing 20. On that occasion, the shield layer 62 of the cable 60 is 
preferably exposed and then fixed by, e.g. winding an 
electrically-conductive tape or the like outside this shield layer 62. In 
addition, the cable 60 is passed through the through hole 53 of the fin of 
an insulating hood 50 as illustrated in FIG. 1. 
(2) Subsequently, the insulating housing 20 thus jointed to the wires is 
placed on the front part of the flat portion 31 of a shield lid member 30, 
while the shield layer 62 of the cable 60 fixed by the 
electrically-conductive tape or the like is inserted into the U-shaped 
shield connection portion 32 of the shield lid member 30, and the shield 
connection portion 32 is caulked and fixed to the shield layer 62 by a 
caulking tool (not shown). In this case, it is recommended that a convex 
rib 33 is formed on the inner surface of the U-shaped shield connection 
portion 32 as clearly shown in FIG. 3C and that both the free end edges of 
the shield connection portion 32 are corrugated at parts of reference 
numerals 33A and 33B as clearly shown in FIG. 3B. The reason is that, in 
this way, the electrical connection and mechanical connection between the 
shield connection portion 32 and the shield layer 62 are made better by 
the caulking. 
(3) Subsequently, the insulating housing 20 in the state of the preceding 
item (2) is inserted inside a shield hood member 40, namely, into the 
enveloping flat portion 45 thereof. On this occasion, the shield lid 
member 30 is registered with the shield hood member 40 so that the 
openings 34' of the engaging arms 34 of the former may correspond to the 
protrusions 43' of the latter, and the protrusions 43' are inserted into 
the openings 34', whereby the shield hood member 40 is placed on the 
shield lid member 30 and coupled and fixed thereto so as to close the 
opening of the rear envelope of the former. At this time, the contact 
portions 11A of the contact pins 11 disposed in the insulating housing 20 
are inserted inside and enclosed with the front envelope 41 of the shield 
hood member 40. Further, the shield connection portion 32 of the shield 
lid member 30 is set in the U-shaped groove 46 of the shield lid member 
40. The coupling and fixation of the shield lid member 30 to the shield 
hood member 40 are effected in such a way that the protrusions 43' snap 
into the openings 34'. 
(4) Thereafter, the shield hood member 40 and the shield lid member 30 are 
gradually inserted and received into the hollow 51 of the insulating hood 
50 in which the cable 60 penetrates the through hole 53. Then, the inner 
side walls 57 of the insulating hood 50 run onto protrusions 42' provided 
on the first side surfaces 42 of the shield hood member 40. When the 
members 40 and 30 are inserted more, the rear end faces of the inner side 
walls 57 and the protrusions 42' come into engagement as clearly shown in 
FIG. 2, whereby the insulating hood 50 is fixed to the shield hood member 
40 in firm engagement. 
(5) Lastly, engagement fixtures 80 with buttons 70 attached thereto are 
inserted from above the insulating hood 50 into engagement fixture 
receiving portions 54 provided on both the sides of the hollow of the 
insulating hood 50 and are thus fastened. Then, the assemblage and the 
wire jointing of this shielded electric connector are completed. The state 
of such fitting and fixation of the engagement fixture 80 to the 
insulating hood 50 is clearly shown in the fragmentary part of FIG. 2. The 
fitting and fixation of the engagement fixture 80 to the insulating hood 
50 will be described in more detail. The engagement fixture 80 is 
gradually inserted from a button receiving portion 55 on the upper side of 
the insulating hood 50. Then, a coming-off-preventive bend 83A with which 
the elastic piece 83 of the engagement fixture 80 is provided abuts 
against and gets on the tapered portion 57.vertline. of the engagement 
projection 57' of the engagement fixture receiving portion 54, and it 
passes the projection 57'. Further, a coming-off-preventive bend 83B 
subsequently gets on the engagement projection 57' and passes it in a 
similar manner. Besides, the coming-off-preventive 83A abuts against the 
stopper lug 58' of the receiving portion 54 and comes in engagement 
therewith. The lower end of a stabilizer head 83C abuts against the inner 
surface of an outer side wall 58, thereby functioning to stabilize the 
latch action of the engagement fixture 80 more. On this occasion, the 
button 70 passes the button receiving portion 55 while bending the 
engagement fixture 80 inwards, and the antiskid corrugation 71 of the 
button 70 is exposed from the recess 56 of the insulating hood 50 as shown 
in FIG. 2. 
Although in the above-mentioned embodiment the shield connection portion 32 
is formed integrally with the shield lid member 30, the shield connection 
portion may be formed integrally with the shield hood member 40. 
Since the present invention is constructed as stated above, the following 
effects are attained: 
(1) Since a shield hood member is unitarily formed with a front envelope 
for completely enclosing the contact portions of contact pins, the 
assemblage is easy, mass production is permitted and the cost can be 
sharply reduced. 
(2) Since a connector is sealed by only a shield hood member and a shield 
lid member, the number of components is very small, and the number of 
steps for assemblage becomes the smallest, so the cost is low and that the 
reliability becomes favorable. 
(3) A shield lid member of simple construction is placed on a shield hood 
member, and an insulating hood which has also a simple construction is 
placed outside them, thereby to obtain a shielded electric connector which 
is covered with a perfect insulator. Therefore, it is possible to obtain 
with ease an electric connector which is of good finger touch and which 
has a design of low cost and good appearance because the insulating hood 
can be made colorful.