Field of the Invention
The present invention relates to an antenna socket to
which an antenna plug is removably connected and, more
specifically, to an antenna socket to which an antenna plug
provided at one end of a coaxial cable for transmission of a
television signal is connected in a removable manner.
Background of the Invention
Japanese Patent Application Publication No. 2001-
135430 discloses an antenna socket to which an antenna plug
provided at one end of a coaxial cable for transmission of a
television signal is connected in a removable manner. The
antenna plug includes a plug pin electrically connected to
an inner conductor of a coaxial cable and a tubular plug
shield electrically connected to an outer conductor of the
coaxial cable and configured to surround the plug pin. The
antenna socket includes a contactor adapted to be connected
to the plug pin of the antenna plug and a tubular socket
shield adapted to be connected to the plug shield. The
socket shield is fixed to a shield plate arranged within the
antenna socket, by virtue of two projections formed at the
rear edge of the socket shield. In a portion of the
circumference of the socket shield, a slit is formed to

extend over the full axial length of the socket shield.
Elastic pieces having some elastic deformability are formed
in the opposite side portions of the slit. The elastic
pieces are elastically pressed against the outer
circumference of the plug shield, whereby the plug shield
and the socket shield are electrically connected to each
other.
In the antenna socket referred to above, the socket
shield is fixed to the shield plate only by two projections
provided at the rear edge of the socket shield in a 18 0
degree spaced-apart relationship. For that reason, the
fixing force of the socket shield tends to become weak. It
is therefore likely that the socket shield may not withstand
the external force applied when attaching the antenna plug.
Since the slit is formed between the two projections, the
portions existing between the slit and the projections
become elastic pieces having elastic deformability. Some
elastic deformability is given to even a portion between the
two projections which is opposite to the slit. Therefore,
it may sometimes the case that, due to the dimensional error
between the plug shield and the socket shield, only the
portion existing between the two projections opposite to the
slit makes contact with the plug shield while the elastic
pieces do not make contact with the plug shield. In that
case, it is not possible to obtain the reliable contact
inherently expected in the two elastic pieces. This may

make the electric connection unstable.
Summary of the Invention
In view of the above, the present invention provides
an antenna socket capable of ensuring reliable electric
connection between a plug shield and a socket shield even if
a small error exists between the plug shield and the socket
shield.
The present invention has been conceived on the basis
of a technical solution of increasing the coupling force of
the socket shield to a shield plate, limiting the elastic
deformability of the portion of the socket shield other than
elastic pieces and concentrating the elastic deformability
to only the elastic pieces.
The present invention provides an antenna " socket to
which an antenna plug provided with a plug pin and a plug
shield surrounding the plug pin is connected in a removable
manner. The antenna socket is configured to realize the
technical solution stated above. The antenna socket
includes an insulating base provided with an insulating
socket having a central hole to which the plug pin is
inserted, a shield plate provided with a tubular socket
shield into which the plug shield is inserted, and a
contactor arranged within the insulating socket of the
insulating base and adapted to be electrically connected to

the plug pin. The insulating socket is configured to extend
through an opening formed in the shield plate and to
protrude frontward. The socket shield is adapted to be
coupled to and electrically connected to the plug shield.
The socket shield surrounds the insulating socket. The
socket shield has a slit extending along a full axial length
of the socket shield. The socket shield has a plurality of
lugs including a first lug, a second lug and a third lug,
which are formed at a rear edge of the socket shield and
spaced apart from one another in a circumferential
direction. The first lug, the second lug and the third lug
are fixed to the shield plate.
The first lug and the second lug are positioned at the
opposite circumferential sides of the slit. The socket
shield includes elastic pieces defined by portions extending
from the slit to the first lug and the second lug. The
third lug is positioned at the opposite side of the first
lug and the second lug from the slit. The first lug and the
second lug are spaced apart from each other along the
circumferential direction with the slit interposed
therebetween. The circumferential distance between the
first lug and the second lug is larger than the
circumferential distance between the third lug and the first
lug or the second lug.
In the antenna socket of the present invention, the
tubular socket shield is fixed to the shield plate by three

lugs spaced apart from one another along the circumferential
direction. The first lug and the second lug are spaced
apart from each other along the circumferential direction
with the slit interposed therebetween. The distance between
the first lug and the second lug is larger than the
circumferential length from the third lug to the first lug
or the second lug. With these technical characteristics,
the present invention realizes the technical solution stated
above and achieves the object mentioned above.
According to one preferred embodiment of the present
invention, the radius of each of the elastic pieces measured
from the center of the socket shield is gradually reduced as
each of the elastic pieces extends away from the first lug
or the second lug. In this case, a large amount of
displacement is applied to the elastic pieces when the
elastic pieces make contact with the plug shield. Using the
elastic restoration force caused by the displacement, it is
possible to obtain reliable electric connection of the
elastic pieces to the plug shield.
In this regard, each of the elastic pieces is curved
along a portion of an oval trajectory. This makes it
possible to design the socket shield with ease.
The elastic pieces are equal in circumferential length
to each other. This is effective in obtaining reliable
electric connection of the elastic pieces to the plug
shield.

The socket shield may be configured such, that the
first lug, the second lug and the third lug are spaced apart
from one another by an angle of 90 degrees. This makes it
possible to reliably limit the elastic deformability in the
portion of the socket shield extending from the first lug to
the second lug through the third lug. Thus the electric
connection of the elastic pieces to the plug shield becomes
stable.
The socket shield may include an extension portion
extending from the first lug to the second lug through the
third lug. The extension portion is constant in radius from
the center of the socket shield. This makes it possible to
obtain a portion conforming to the outer circumference of
the circular plug shield. Thus it becomes easy to connect
the socket shield to the plug shield.
The shield plate may have three slots formed along a
peripheral edge of the opening. The socket shield is fixed
to the shield plate by inserting the first lug, the second
lug and the third lug into the slots and bending the first
lug, the second lug and the third lug onto the shield plate.
This makes it easy to couple the socket shield to the shield
plate.
With the technical features of the antenna socket of
the present invention, the tubular socket shield is fixed to
the shield plate by three lugs spaced apart from one another
along the circumferential direction. The first lug and the

second lug are spaced apart from each other along the
circumferential direction with the slit interposed
therebetween. The distance between the first lug and the
second lug is larger than the circumferential length from
the third lug to the first lug or the second lug.
Accordingly, it is possible to provide an antenna socket
capable of ensuring reliable electric connection between a
plug shield and a socket shield even if a small error exists
between the plug shield and the socket shield.
Brief Description of the Drawings
The objects and features of the present invention will
become apparent from the following description of
embodiments, given in conjunction with the accompanying
drawings, in which:
Fig. 1 is a front perspective view showing an antenna
socket according to one embodiment of the present invention;
Fig 2 is a rear perspective view of the antenna
socket;
Fig. 3 is an explanatory view illustrating a coaxial
cable used in the antenna socket;
Fig. 4 is an exploded perspective view showing major
portions of the antenna socket;
Fig. 5 is a schematic view showing an antenna plug
connected to the antenna socket;

Fig. 6 is a perspective view showing a socket module
making up the antenna socket;
Fig. 7 is a perspective view showing a socket shield
employed in the antenna socket;
Fig. 8 is a rear view of the socket shield;
Fig. 9 is a schematic view showing a modified example
of the socket shield differing in the positions of
projections;
Fig. 10 is a schematic view showing another modified
example of the socket shield differing in the positions of
projections; and
Fig. 11 is a schematic view showing a further modified
example of the socket shield differing in the number of
projections.
Detailed Description of the Embodiments
An antenna socket 10 0 according to one embodiment of
the present invention is configured to receive an antenna
plug 20 provided with a plug pin 21 and a plug shield 22
surrounding the plug pin 21 as shown in Fig. 5.
Referring to Figs. 1 and 2, the antenna socket 100 is
embedded in, e.g., a wall surface, when in use. On the rear
surface thereof, the antenna socket 100 is connected to a
coaxial cable 10 (see Fig. 3) for transmission of a
televi-sion signal extending from the outdoor to the indoor.

On the front surface thereof, the antenna socket 100 is
removably coupled to an antenna plug 20 formed at one end of
a coaxial cable adapted to be connected to a television set.
Referring to Fig. 3, the coaxial cable 10 includes a
inner conductor 11 and an outer conductor 12.
As shown in Figs. 4 and 6, the antenna socket 100
includes a housing 30 having an insertion hole 31 to which
the antenna plug 20 is inserted and a socket module 90.
The socket module 90 includes a shield frame 80 made
of an electrically conductive metal and arranged to cover
the rear surface of the housing 30, a shield plate 5 0 made
of an electrically conductive metal and electrically
connected to the shield frame 80 and an insulating base 60
held between the shield frame 80 and the shield plate 50.
The shield plate 50 is fixed to the shield frame 8 0 by
inserting claws 53 formed at the upper end of the shield
plate 50 into holes 8 2 formed in the shield frame 8 0. The
shield frame 8 0 has side pieces and claws 8 3 formed in the
side pieces. The socket module 90 is fixed to the housing
3 0 by fitting the claws 8 3 into holes 32 formed in the side
pieces of the housing 30.
The insulating base 60 is made of an electrically
insulating material. The insulating base 60 includes an
insulating socket 61 into which a plug pin 21 (see Fig. 5)
is inserted. The insulating socket 61 extends through an
opening 51 formed in the shield plate 5 0 and protrudes

frontward.
A pin catcher 71 formed at the front end of a
contactor 7 0 adapted to be electrically connected to the
inner conductor 11 of the coaxial cable 10 connected to the
rear surface of the shield frame 8 0 is arranged within a
central hole 62 of the insulating socket 61 and is adapted
to be electrically connected to the plug pin 21. A terminal
72 into which the inner conductor 11 of the coaxial cable 10
is inserted is formed at the rear end of the contactor 7 0.
The terminal 72 is held within a terminal case 65 fixed to
the shield frame 80. The terminal case 65 is made of an
electrically insulating material. A downwardly-opened
insertion hole is formed in the portion of the terminal case
65 extending through the opening 81 of the shield frame 80
and protruding rearward. The terminal 72 is electrically
connected to the inner conductor 11 of the coaxial cable 10
inserted into the downwardly-opened insertion hole.
The coaxial cable 10 is fixed in place by a pressing
clamp 85 fastened to the rear surface of the shield frame 80
with a screw 8 6 so that the coaxial cable 10 can extend
along the rear surface of the shield frame 8 0. The outer
conductor 12 of the coaxial cable 10 is electrically
connected to the shield frame 80.
The shield plate 50 covers the front surface of the
insulating base 60 and holds a tubular socket shield 40 for
surrounding the forwardly-protruding insulating socket 61 of

the insulating base 60. The socket shield 40 surrounds the
insulating socket 61 with a specified distance therebetween.
The inner circumferential surface of the socket shield 4 0
makes contact with the outer circumference of the plug
shield 22 of the antenna plug 20, whereby the socket shield
40 and the plug shield 22 are electrically connected to each
other. The socket shield 4 0 is made of the same kind of
electrically conductive material as the shield plate 50 and
is formed independently of the shield plate 50. The socket
shield 40 is caulked to the shield plate 50 by inserting
lugs 43 (44, 45 and 4 6) formed at the rear edge of the
socket shield 40 into slots 52 formed in the shield plate 50
and then folding back the lugs 43.
As shown in Figs. 7 and 8, a slit 41 extending along
the full axial length of the socket shield 40 is formed in
the socket shield 40, thereby giving some elastic
deformability to the portions of the socket shield 4 0
existing at the circumferential opposite sides of the slit
41. The lugs 43 formed at the rear edge of the socket
shield 40 includes a first lug 44, a second lug 45 and a
third lug 46, which are spaced apart from one another along
the circumferential direction. The first lug 44 and the
second lug 45 are positioned at the circumferential opposite
sides of the slit 41. In the socket shield 40, the portions
extending from the slit 41 to portions corresponding to the
first lug 44 and the second lug 45 define a pair of arc-

shaped elastic pieces 4 2 making elastic contact with, the
outer circumference of the plug shield 22. The third lug 4 6
is positioned at the opposite side from the slit 41 with
respect to the first lug 44 and the second lug 45. The
portion of the socket shield 40 extending from the first lug
4 4 to the second lug 4 5 through the third lug 46 becomes a
fixed portion having substantially no elastic deformability.
The third lug 46 is spaced apart at an angular of 90
degrees from each of the first lug 44 and the second lug 45
on the basis of the center of the socket shield 4 0. The
slit 41 is spaced apart from the third lug 4 6 formed in the
position by 180 degrees. The elastic pieces 42 are equal in
perimeter (the circumferential length) to each other. The
socket shield 4 0 has an inner diameter ranging from about
9.0 mm to about 10.0 mm and a thickness of about 0.5 mm.
The slit 41 is about 1.0 mm in width.
The extension portion of the socket shield 4 0
extending from the first lug 44 to the second lug 45 through
the third lug 46 has a constant radius from the center of
the socket shield 40.
Each of the elastic pieces 42 is curved along a
portion of an oval trajectory such that the radius of each
of the elastic pieces 42 is gradually reduced as each of the
elastic pieces 42 extends away from the first lug 4 4 or the
second lug 45. This assists in increasing the contact force
applied to the outer circumference of the plug shield 22.

In other words, when a plug shield having a perfectly
circular shape is inserted into the socket shield 40, the
plug shield applies a force against the elastic pieces 42 to
displace the elastic pieces 42 outward. Using a force
resisting to this displacement, it is possible to increase
the contact force acting between the elastic pieces 42 and
the plug shield 22.
A plurality of guide pieces extending obliquely
outward is formed in the front edge of the socket shield 40.
This makes it easy to insert the plug shield 2 2 into the
socket shield 40. The guide pieces are spaced apart from
each other along the circumferential direction. The guide
pieces existing at the circumferential opposite sides of the
slit 41 are shorter in perimeter than the remaining guide
pieces. The guide pieces extending to the side of the
elastic pieces 42 beyond the circumferential points
corresponding to the first lug 44 and the second lug 45 are
separated from the guide pieces existing at the
circumferential opposite sides of the slit 41 so that
increased elastic deformability is given to the portions of
the elastic pieces 42 corresponding to the guide pieces
existing at the circumferential opposite sides of the slit
41.
While each of the elastic pieces 4 2 is curved along a
portion of an oval trajectory in the aforementioned
embodiment, the present invention shall not be limited

thereto. Each of the elastic pieces 42 may be curved along
other trajectories, as long as the distance from each of the
elastic pieces 42 to the center of the socket shield 40 is
gradually reduced toward the slit 41.
While two lugs 44 and 4 5 of the socket shield 4 0 are
spaced apart by 90 degrees from the other lug 4 3 opposite to
the slit 41 in the aforementioned embodiment, the present
invention is not limited thereto. For example, two lugs 4 4
and 4 5 of the socket shield 4 0 may be spaced apart from the
other lug 4 6 opposite to the slit 41 by an angle of more
than 90 degrees as shown in Fig. 9 or an angle of less than
90 degrees as shown in Fig. 10,
Alternatively, as shown in Fig. 11, it is also
possible to provide four lugs 43 spaced apart at an equal
interval within an angular extent of 180 degrees.
The socket shield 4 0 may include an extension portion
extending from the first lug 44 to the second lug 45 through
the third lug 46, the extension portion being constant in
radius from the center of the socket shield 40.
The width of the slit 41 can be changed unless the
elastic pieces 42 loses its function of making pressure
contact with the outer circumference of the plug shield 22.
While the respective lugs 4 3 are caulked to the shield
plate 50 in the aforementioned embodiment, the present
invention is not limited thereto. For example, the lugs 4 3
may be fixed by welding.

While the invention has been shown and described with
respect to the embodiments, it will be understood by those
skilled in the art that various changes and modification may
be made without departing from the scope of the invention as
defined in the following claims.

We Claim:
1. An antenna socket to which an antenna plug provided
with a plug pin and a plug shield surrounding the plug pin
is connected in a removable manner, the antenna socket
comprising:
an insulating base provided with an insulating socket
having a central hole to which the plug pin is inserted;
a shield plate provided with a tubular socket shield
into which the plug shield is inserted; and
a contactor arranged within the insulating socket of
the insulating base and adapted to be electrically connected
to the plug pin,
wherein, the insulating socket extends through an
opening formed in the shield plate and protruding frontward,
the socket shield is adapted to be coupled to and
electrically connected to the plug shield, the socket shield
surrounds the insulating socket and has a slit extending
along a full axial length of the socket shield,
the socket shield has a plurality of lugs including a
first lug, a third lug and a second lug, which are formed at
a rear edge of the socket shield and spaced apart from one
another in a circumferential direction, the lugs being fixed
to the shield plate, the first lug and the second lug being
positioned at the opposite circumferential sides of the slit
so that the socket shield includes elastic pieces defined by

portions extending from the slit to the first lug and the
second lug, the third lug being positioned at the opposite
side of the first lug and the second lug from the slit, the
first lug and the second lug being spaced apart from each
other along the circumferential direction with the slit
interposed therebetween, the circumferential distance
between the first lug and the second lug being larger than
the circumferential distance between the third lug and the
first lug or the second lug.
2 . The socket of claim 1, wherein the radius of each of
the elastic pieces measured from the center of the socket
shield is gradually reduced as each of the elastic pieces
extends away from the first lug or the second lug.
3. The socket of claim 2, wherein each of the elastic
pieces is curved along a portion of an oval trajectory.
4. The socket of any one of claims 1 to 3, wherein the
elastic pieces are equal in circumferential length to each
other.
5. The socket of any one of claims 1 to 4, wherein the
first lug and the second lug are spaced apart from the third
lug by an angle of 90 degrees.

6. The socket of any one of claims 1 to 5, wherein the
socket shield including an extension portion extending from
the first lug to the second lug through the third lug, the
extension portion having a constant in radius from the
center of the socket shield.
7 . The socket of any one of claims 1 to 6, wherein the
shield plate has three slots formed along a peripheral edge
of the opening, the socket shield being fixed to the shield
plate by inserting the first lug, the second lug and the
third lug into the slots and caulking the first lug, the
second lug and the third lug to the shield plate.