Coaxial cable connector

A connector for connection of a coaxial cable comprises a cylindrical holder composed of a support member and a lid member of semi-cylindrical configurations made of insulator material, and a center contact stored and held in the front end portion of the cylindrical holder. One end of the coaxial cable is held in a cable holding section in the rear of the center contact, a core wire of the coaxial cable is connected to the center contact, a ferrule is disposed in an opening formed at the cable holding section, an exposed outer conductor portion of the coaxial cable is folded and disposed on the ferrule and connected electrically thereto, the cylindrical holder is fitted and inserted in a metallic cylindrical body, and the ferrule is elastically deformed thereby to electrically connect the cylindrical body and the outer conductor together.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to a coaxial cable connector used for connection of 
a coaxial cable with a contact unit mounted on a circuit board, for 
example. 
2. Description of the Prior Art 
FIGS. 1A through 1C illustrate the connection process of a coaxial cable 
with a coaxial cable connector widely used hitherto in this field. 
Referring to these drawings, a nut 10 is slipped onto a coaxial cable 11, 
and a sheath 12 is removed at the end portion of the coaxial cable 11 so 
as to expose an outer conductor 13, as shown in FIG. 1A. An inner 
insulator 15 inside the end portion of the exposed outer conductor 13 is 
removed, an end portion 13a of the outer conductor 13 is made narrower, 
and a washer 14a, gasket 14b and clamp 14c are then slipped in this order 
onto the sheath 12. At this state, a collar of the clamp 14c is caused to 
abut on the end face of the sheath 12. As shown in FIG. 1B, the outer 
conductor 13 is then cut to a given length, its netted wires are 
unraveled, the thus unraveled portion is folded down and disposed on the 
outer surface of the clamp 14c as indicated by 13b. The exposed inner 
insulator 15 is then cut to a given length to expose a core wire 16, and 
this core wire 16 is also cut to a given length. The core wire 16 is 
inserted into a hole of a female contact 17, soldered and secured in 
place, as shown in FIG. 1C. At this stage, the coaxial cable 11 is 
inserted and fitted in a jack body 21, and secured by turning the nut 10 
with respect to the jack body, as shown in FIG. 2. 
On the other hand, when it is desired to form a plug type connector, a male 
contact 23 (see FIG. 3), in place of the female contact 17, is secured to 
the core wire 16 of the coaxial cable semi-finished as shown in FIG. 1B. 
At this stage, the coaxial cable is inserted into a plug body 22 and 
secured in place by turning the nut 10 with respect to the plug body 22, 
as shown in FIG. 3. 
As is apparent from the foregoing, the conventional coaxial cable connector 
needs a number of parts or segments, its structure is complicated, it can 
hardly be miniaturized and is not suited for a machining work. Further, 
there are several parts which must be attached previously to the coaxial 
cable at the time of connection; thus, if any parts were left unattached 
the assembling process must be started over again. Furthermore, before 
attaching the plug body or jack body to the coaxial cable the exposed 
length of the inner insulator 15 and/or core wire 16 must be defined 
precisely; if not, the contacts 17, 23 cannot be positioned at a given 
location inside the bodies 21, 22 in directions along the axial center. 
Accordingly, the connection was not easily made in case of the 
conventional coaxial cable connector. 
SUMMARY OF THE INVENTION 
It is the object of the present invention to overcome the foregoing 
disadvantages of the conventional connector, and to provide a coaxial 
cable connector which is simple in overall structure, needs few parts, is 
miniaturizable, permits a relatively large degree of tolerance for the 
coaxial cable processed, and can easily be attached and connected to the 
coaxial cable. 
According to the present invention, a cylindrical holder is composed of a 
support member and a lid member of semi-cylindrical configuration and made 
of insulator material, inside the front end portion of the cylindrical 
holder a contact holding section is formed, and in this contact holding 
section a center contact is stored and held in place. This center contact 
is designed so that as a mating contact is inserted from the front end 
into the cylindrical holder the two come into contact with one another. 
The inside of the rear end portion of the cylindrical holder functions as 
a cable holding section, so that one end of a coaxial cable is stored and 
held inside the cylindrical holder in a further rear of the center contact 
and the other end is led outward from the rear end of the cylindrical 
holder. 
A core wire of the coaxial cable is exposed at the inserted end and this 
core wire is electrically connected to the center contact. The cylindrical 
holder is formed in the cable holding section with an opening, in this 
opening a ferrule made of elastic material is disposed, on the outer face 
of this ferrule a folded outer conductor portion of the coaxial cable is 
disposed, the thus processed cylindrical holder is fitted and inserted 
into a cylindrical metallic body, and the ferrule is elastically deformed, 
whereby the folded outer conductor and cylindrical body are electrically 
connected together. 
As will be apparent from the foregoing, according to the present invention, 
the center contact, coaxial cable and ferrule can be stored inside the 
support member with the lid member opened and connected to one another 
through a simple assembling operation. The support member and lid member 
are coupled together by a bendable portion; thus, these members can be 
fabricated as a single molded body. The ferrule can be produced by 
pressing. Accordingly, all parts can be produced through a simple process, 
and the number of parts can be reduced. By positioning and holding the 
center contact in the contact holding section inside the cylindrical 
holder the position in the axial direction of the center contact is 
determined correctly, and a large dimensional tolerance is allowed in 
processing the coaxial cable.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The coaxial cable connector according to the present invention will now be 
described with reference to the drawings showing its embodiments. 
FIG. 4 is a perspective view showing in the open state the structure of a 
cylindrical holder 31 of an embodiment of the coaxial cable connector 
according to the present invention. The holder 31 is made of an insulating 
material, such as synthetic resin, and has a substantially cylindrical 
shape. The cylindrical holder 31 is divided along the axial direction into 
two substantially semi-cylindrical parts; thus, it is composed of a 
support member 32 which is substantially semi-cylindrical over the whole 
length of the connector, and lid members 33-1 and 33-2 which are attached 
pivotably to, and adapted to cover, the support member 32. 
In the embodiment the lid members 33-1 and 33-2 are coupled pivotably to 
the side margin of the support member 32 by respective hinge portions 34-1 
and 34-2. The support member 32, lid members 33-1 and 33-2, and hinge 
portions 34-1 and 34-2 are made by synthetic resin in the form of a single 
molded body. The lid members 33-1 and 33-2 are positioned with respect to 
the support member 32 so as to leave a space therebetween in the center 
portion of the support member. Accordingly, in the covered state of the 
support member 32 resulting from pivoting of the lid members 33-1 and 33-2 
toward the support member 32, there is formed an opening 35 between these 
lid members 33-1 and 33-2 in the center portion in the axial direction of 
the cylindrical holder 31. 
One end of the coaxial cable is loaded and held inside the cylindrical 
holder 31, and the other end is led outward from the rear end of the 
cylindrical holder 31. Inside the front end portion of the cylindrical 
holder 31 a center contact 38 (FIG. 6) is stored and held in place. 
As shown in FIG. 5, a sheath 12 of the coaxial cable 36 is cut off at the 
connection end so as to expose an outer conductor 13, and the thus exposed 
outer conductor 13 is twisted into a braid shape and led out sideways, 
this being treated as an outer conductor connection segment 13d. A portion 
of inner insulator 15 from which the outer conductor 13 is taken away is 
then removed so as to expose a core wire 16 at the end of the coaxial 
cable 36. 
As shown in FIG. 6, the center contact 38 comprises an elastic clamp member 
40 which, in the case of a female contact, is made substantially 
cylindrical and has formed therein notches 39 extending in its lengthwise 
direction, these notches 39 being made narrower toward the front end of 
the contact so that the front contact portions are closer to each other 
and biased elastically in directions orthogonal to the axial center. From 
the rear end of this cylindrical elastic clamp member 40 an integral 
connection segment 41 is led out rearward. In a mid-portion of the 
connection segment 41 a connection portion 41a is formed projecting 
widthwise. As shown in FIGS. 8 and 9, this center contact 38 is stored and 
held in a contact holding section 44 inside the front end portion of the 
cylindrical holder 31. On the sides of the rear end of the contact holding 
section 44 positioning segments 43-1 and 43-2 are formed on the support 
member 32 in opposition to each other, and between these positioning 
segments 43-1 and 43-2 is disposed a bent portion 41-C on the side of the 
elastic clamp member 40 of the connection segment 41. At this stage, the 
rear end face of the elastic clamp member 40 abuts on the front end of the 
positioning segments 43-1 and 43-2, whereby the center contact 38 is 
positioned correctly. The rear end portion of the elastic clamp member 40 
is fitted roughly into the contact holding section 44. 
The rear end portion of the connection segment 41 is laid between clamp 
segments 45-1 and 45-2 which are spaced rearward from the positioning 
segments 43-1 and 43-2 and formed on the support member 32. The section 
between these positioning segments 43-1, 43-2 and clamp segments 45-1, 
45-2 defines a core wire connection section 46. The rear portion of the 
clamp segments 45-1, 45-2 is treated as a cable holding section 47, in 
which one end portion of the coaxial cable 36 still having the sheath 12 
is stored and held in place. As shown in FIG. 10, the exposed inner 
insulator 15 is positioned and placed between the clamp segments 45-1 and 
45-2, and the exposed core wire 16 is placed on the connection segment 41 
positioned in the core wire connection section 46. 
With respect to the opening 35 left between the lid members 33-1 and 33-2 a 
ferrule 51 is disposed in such a way as is shown in FIG. 10. In FIG. 10, 
the lid member 33-2 is alone closed to cover the support member 32. 
The ferrule 51 is substantially semi-cylindrical as shown in FIG. 7A and 
formed by bending an elastic conductive plate made of montifiere metal, 
for example. On the top of the semi-cylindrical ferrule 51 a shallow 
concave portion 52 is formed over the whole length in parallel with the 
axial center, and from the center portion of either side margin of the 
ferrule 51 project integral elastic holding segments 53-1 and 53-2. 
In outer peripheral portions of the support member 32 on either side of the 
opening 35 coupling notches 54-1 and 54-2 are formed in which the elastic 
holding segments 53-1 and 53-2 are fitted. As shown in FIGS. 10 and 11, 
when the coaxial cable 36 is loaded into the cable holding section 47 of 
the support member 32, the ferrule 51 is attached to the support member 
32. The ferrule 51 is temporarily secured to the support member 32 by 
bringing the elastic holding segments 53-1 and 53-2 of the ferrule 51 into 
elastic engagement with the coupling notches 54-1 and 54-2, respectively. 
Inside the side margins of the support member 32 on either side of the 
opening 35 guide segments 47-1 and 47-2 are also formed integrally. 
On the concave portion 52 of the ferrule 51 the outer conductor connection 
segment 13d of the outer conductor 13 of the coaxial cable 36, which was 
previously twisted into a braid shape and led out sideways, is disposed 
and folded there, this outer conductor connection segment 13d then having 
connected electrically to the concave portion 52 by soldering, for 
example. The soldering operation can be achieved easily because of the 
foregoing temporary securing of the ferrule 51. 
In the support member 32 and lid member 33-1 windows 48-1 and 48-2 are 
formed respectively at a position corresponding to the core wire 
connection section 46. Accordingly, connection of the core wire 16 of the 
coaxial cable 36 with the connection portion 41a of the connection segment 
41 can be achieved, after the lid member 33-1 has been pivoted to cover 
the support member 32, through the windows 48-1 and 48-2 by spot welding, 
for example. Of course, this connection between the connection segment 41 
and core wire 16 may be achieved by soldering or pressure welding. 
At this stage, the cylindrical holder 31 comprising the support member 32 
and lid members 33-1 and 33-2 in the closed state is press-fitted into a 
cylindrical body 58 made of conductive material, such as brass, from the 
front end as shown in FIG. 12. The cylindrical body 58 is then pushed at 
several spots of its rear end portion into a ring-shaped concave portion 
49 formed on the outer periphery of the cylindrical holder 31 so as to 
leave calked recesses 50, whereby the cylindrical body 58 and cylindrical 
holder 31 are secured together. As the cylindrical holder 31 is 
press-fitted into the cylindrical body 58, the ferrule 51 comes into 
elastic contact with the cylindrical body 58 and deforms elastically, 
whereby both are electrically connected satisfactorily. 
The outer diameter of the front end portion of the cylindrical holder 31 is 
reduced to form a ring-shaped stepped portion or shoulder 55, and the 
inner diameter of front end portion of the cylindrical body 58 is also 
reduced to form a ring-shaped stepped portion or shoulder 56, so that when 
the cylindrical holder 31 is inserted into the cylindrical body 58 the 
shoulder 55 abuts on the shoulder 56, whereby holder 31 and body 58 are 
positioned correctly relative to one another. 
As shown in FIGS. 4 and 8, on the inner surface of the cable holding 
section 47 of the support member 32 and on the inner surface of the lid 
member 33-2, elongate projections 57 extending circumferentially and 
having a triangle shape in cross section are formed at an appropriate 
interval, which bite into the sheath 12 of the coaxial cable 36 so as to 
make certain the holding of the coaxial cable 36. In the front end of the 
cylindrical holder 31 a small hole 59 is formed correspondingly to a 
center hole of the center contact 38, and guided by this small hole 59 a 
mating contact is inserted into the cylindrical holder 31, and then 
press-fitted into the center contact 38 so that it comes into contact 
therewith. 
In the cylindrical holder 31 of the foregoing embodiment, the support 
member 32 and lid members 33-1 and 33-2 are coupled by the hinge portions 
34-1 and 34-2 into a single body, so that because of the elasticity of 
synthetic resin the support member 32 and lid members 33-1 and 33-2 tend 
to maintain the open position. Accordingly, in this open state, the 
elastic 40 and connection segment 41 are put on the support member 32, the 
outer conductor connection segment 13d is led out sideways, and the core 
wire 16 and connection segment 41 are connected together. Then, the lid 
member 33-1 is closed, the thus assembled unit is inserted into the 
cylindrical body 58, the ferrule 51 is attached to the cylindrical holder 
31, the outer conductor connection segment 13d is soldered to the ferrule 
51, the cylindrical holder 31 is inserted further into the cylindrical 
body 58, the lid member 33-2 is closed, and the cylindrical holder 31 is 
further inserted into the cylindrical body 58. At the time of insertion of 
the ferrule, an appropriate tool may be used when necessary. 
The mating connector to be joined and connected with the connector 
according to the present invention may be structured as shown in FIG. 13, 
for example. A pin contact 63 is inserted in an insulation block 62 and 
secured in place, the insulation block 62 is fitted in one end of an outer 
conductor 64 and secured in place, and the thus assembled members are 
supported by a board 61 and wired thereto. The end of the outer conductor 
64 remote from the board 61 is split into several parts. As the 
cylindrical body 58 shown in FIG. 12 is fitted into the outer conductor 
64, the pin contact 63 is inserted into the cylindrical holder 31 and 
coupled to the center contact 38, so that the core wire 16 of the coaxial 
cable 36 is connected electrically to the pin contact 63. 
The ferrule 51 can be produced in the alternative configuration shown in 
FIG. 7B, by making substantially flat the top of a semi-cylindrical member 
and generating coupling segments 72-1 through 72-3 on the flat top, which 
may be formed by cutting top portions and erecting them in the same 
direction. In the case of using this alternative ferrule 51, the outer 
conductor connection segment 13d, previously twisted into a braid shape 
and led out sideways, is put on the coupling segments 72-1 through 72-3 of 
the ferrule 51 and under the above state the cylindrical holder 31 is 
inserted into the cylindrical body 58 so as not to cause the coupling 
segments 72-1 through 72-3 to be caught on the cylindrical body, whereby 
the outer conductor connection segment 13d comes into elastic contact with 
the cylindrical body 58 by means of the coupling segments 72-1 through 
72-3. 
The coaxial cable connector according to the present invention has fewer 
structural parts than the prior art connector, and can be produced at a 
high degree of quality with low manufacturing costs by pressing and 
molding. According to the present invention, connection of the center 
contact 38 with the core wire 16 can easily be achieved in the open state 
of the lid members after the coaxial cable 36 and center contact 38 are 
disposed on the support member 32, and connection between the ferrule 51 
and the outer conductor 13 can be achieved easily too. Therefore, the 
assembling operation is simplified and the connector is miniaturizable. 
Since the position in the axial direction of the coaxial cable 36 with 
respect to the support member 32 is determined by abutment of the folded 
point of the outer conductor connection segment 13d on the front side 
margin of the ferrule 51, the projecting length of the core wire 16 is 
sufficient if it falls between l.sub.1, or the connection portion 41a of 
the connection segment 41 and l.sub.2, or the bent portion of the same, as 
shown in FIG. 10. Similarly, the projecting length of the inner insulator 
15 is sufficient if it falls between S.sub.1, or the rear end of the clamp 
segments 45-1 and 45-2 and S.sub.2, or the front end of the same. 
Accordingly, a relatively large tolerance is permitted in processing the 
coaxial cable, i.e. a rough processing of the coaxial cable is permitted. 
For reference, the position in the axial direction of the center contact 
40 is determined properly and rightly by putting it on the cylindrical 
holder 31 and on the basis of the positioning means, which are the 
ring-shaped stepped portions 55 and 56, and becomes effective when the 
cylindrical holder 31 is inserted into the cylindrical body 58. 
Although in the embodiment the elastic clamp member 40 is drawn out 
frontward by putting in and taking out the mating contact relatively, the 
bent portion 41-C of the connection segment 41 functions as a buffering 
portion, so that no mechanical force is applied to the connected point 
between the core wire 16 and the connection segment 41, and this connected 
point is kept stably. Further, as shown in FIGS. 4 and 9, by designing the 
positioning segments 43-1 and 43-2 and clamp segments 45-1 and 45-2 so as 
to project beyond the support member 32 and causing them to abut almost on 
the inner surface of the lid member 33-1, the lid member 33-1 is 
positioned properly when closed. 
In modification of the invention, the support member 32 may be made 
independent of the lid members 33-1, 33-2. A male contact may be used as 
the center contact 38. It is also possible to make relatively large the 
diameter of the cylindrical body 58, thereby to result in a loose 
insertion of the cylindrical holder 31 into the cylindrical body 58. In 
this case, as shown in FIG. 14, a portion of the cylindrical body 58 
corresponding to the furrule 51 is calked into a hexagonal shape so that 
his calked portion 65 causes the ferrule 51 and cylindrical body 58 to 
come into elastic contact with one another.