Field of the Invention
The present invention relates to a direct current (DC)
outlet.
Background of the Invention
There has been known a DC outlet for supplying a DC
power to an electric device, such as a radio and a telephone,
a driving power source of which is a DC power source (see,
e.g., Japanese Patent Application Publication No. H07-
015835(JP07-015835A), paragraphs [0021] to [0023]).
The DC outlet of JP07-015835A includes a main body
that is accommodated in a switch box provided inside a wall;
and a converter provided inside the main body to convert an
AC power to a DC power. Further, the DC outlet includes an
AC connection terminal provided on a rear side of the main
body which faces the switch bov; and an outlet part provided
on a front side of the main body which faces an inside of a
room. A power line of an AC power source installed inside
the wall is connected to the AC connection terminal, and a
plug of an electric device is detachably connected to the
outlet part. Accordingly, when the power line of the AC
power source is connected to the AC connection terminal of
tne DC outlet, an AC power is converted to a DC power by the
converter, so that the DC power can be supplied to the
electric device having the plug that is connected to the
outlet part thereof.
In the meantime, when a plug is connected to and
disconnected from a DC outlet, an arc may be generated.
Especially, in the case of the DC outlet for supplying a DC
power, the generated arc may be maintained as compared with
an AC outlet and, thus, the DC outlet needs an arc
protecting unit. However, the DC outlet of JP07-015835A has
an outlet part of a pin-jack type terminal and no member for
surrounding plug pins of a plug. Accordingly, the generated
arc may be aeen from the outside.
As an example of a DC outlet including an arc
protecting unit, there has been disclosed a plug and a
socket of a safety extra low voltage (SELV) voltage
standardized by the IEC standard (CEI/IEC 60906-3). Figs.
37C and 37D show a plug 110 standardized by the IEC standard.
Two plug pins 112 are arranged inside a cylindrical portion
ill provided at a front end portion of the plug 110.
Meanwhile, as shown in Figs. 37A and 37B, a socket 100
includes a circular opening 101 through which the
cylindrical portion 111 of the plug 110 is inserted; a
cylindrical protruding portion 102 which protrudes from the
circular opening 101 to be inserted into the cylindrical
portion 111; pin-inserting holes 103 which are opened to an
front end surface of the protruding portion 102; and pin-
receiving pieces 104 provided inside the protruding portion
102 to communicate with the pin-inserting holes 103. When
the plug lio is connected to the socket 100," the plug pins
112 which are inserted into the protruding portion 102
through the pin-inserting holes 103 are respectively engaged
with the pin-receiving pieces 104, so that a power is
supplied from the socket 100 to the plug 110.
As shown in Pigs. 37A to 3 7D, in the socket 100
standardized by the IEC standard, the two pin-inserting
holes 103 are opened on a line LI extending through the
center of the protruding portion 102 and at two symmetric
positions with regard to the center of the protruding
portion 102. For that reason, a keyway 105 is formed on a
peripheral surface of the protruding portion 102 and a rib
113 is formed on an inner peripheral surface of the
cylindrical portion 111 such that the plug pins 112 would
not be inserted into the pin-inserting holes 103 in a state
that their polarities are misaligned.
Further, the plug 110 and the socket 100 standardized
by the IEC standard correspond to four kinds of supply
voltages. To identify the kinds of supply voltages, the
socket 100 and the plug 110 respectively include a voltage-
identifying groove 106 formed on the peripheral surface of
the protruding portion 102 at a predetermined angle with
regard to the keyway 105; and a voltage-identifying rib 114
protrudently formed on the inner peripheral surface of the
cylindrical portion 111 of the plug 110 at a predetermined
angle with regard to the rib 113.
Then, the plug 110 is prevented from being inserted
into the socket 100 reversely or wrongly with their
polarities misaligned by engaging the keyway 105 and the
voltage-identifying groove 105 with the; rib 113 and the
voltage-identifying rib 114, respectively. When, however,
the cylindrical portion 111 is inserted into the circular
opening 101, it is required to find positions at which the
ribs 113 .and 114. o£ the cylindrical portion 111 are
respectively engaged with the keyway 105 and the groove 106
of the socket 100 while rotating the plug 110. Accordingly,
it becomes inconvenient to use the socket 100 and the plug
no.
To prevent the plug 110 from being reversely inserted
into the socket 100 without using the keyway 105 and the rib
113, it is considered to arrange the two pin-inserting holes
103 at a side below or above the line LI (e.g., at a side
below the line LI as shown in Fig. 37A by the dotted line).
Since, however, the protruding portion 102 has the
cylindrical shape, the distance between the pin-inserting
holes 103 becomes closer when the pin-inserting holes 103
are arranged at a side below or above line LI. Accordingly,
the socket 100 becomes scaled up in order to obtain an
insulating distance.
Summary of the Invention
In view of the above, the present invention provides a
DC outlet capable of preventing a plug from being reversely
inserted thereto without being scaled up and easily aligning
the plug therewith when the plug is connected thereto.
in accordance with an aspect of the present invention,
there is provided a direct current (DC) outlet to which a
plug is adapted to be connected to supply a DC power to the
plug, the plug including a plurality of plug pins having a
circular bar shape; and a substantially quadrangular-shaped
surrounding wall for surrounding the plug pins. The DC
outlet includes: an outlet main body having an outlet unit
to which the plug is adapted to be connected, che outlet
unit being provided in a front surface of the outlet main
body. The outlet unit includes a plug-receiving portion
having a plurality of pin-inserting holes into which the
plug pins of the plug are inserted, the plug-receiving
portion having a substantially quadrangular shape viewed
from the front thereof; an insertion groove formed to
surround a periphery of the plug-receiving portion, the
insertion groove being adapted to receive the surrounding
wall of the plug; and pin-receiving pieces for being
connected with the plug pins that are respectively inserted
through the pin-receiving holes. Two of the pin-receiving
holes corresponding to the pin-receiving pieceo for
supplying a DC power are arranged along one side of the
plug-receiving portion serving as a reference side and
offset closer to the reference side than an opposite side to
the reference side.
A shape of at least one of the plug-receiving portion
and the insertion groove, viewed from the front thereof, may
be partially changed depending on the kinds of a supply
voltage or a supply current.
The shape of the insertion groove viewed from the
front may be changed such that an area of iithe plug-receiving
portion is decreased as compared with a case that the plug-
receiving portion has the substantially quadrangular shape
viewed from the front.
The shape of the insertion groove viewed from the
front may be changed differently depending on the kinds of
the supply voltage or the supply current by cutting at least
one side of the substantially quadrangular shape of the
plug-receiving portion depending on the kinds of the supply
voltage or the supply current, and forming the insertion
groove along an outer periphery of the plug-receiving
portion.
A portion of the insertion groove whose shape is
changed depending on the kinds of the supply voltage or the
supply current may be closer to the opposite side to the
reference side than the reference side.
The shape of the insertion groove viewed from the
front may be changed such that an area of the plug-receiving
portion is increased as compared with a case that the plug-
receiving portion has the substantially quadrangular shape
viewed from the front.
The shape of the insertion groove viewed from the
front may be changed by forming an extension groove
extending from the insertion groove. In this case, the
extension groove may be formed by extending a part of the
insertion groove into the plug-receiving portion, and the
extension groove may be provided closer to the opposite side
to the reference side of the plug-receiving portion than the
reference side.
Alternatively, the extension groove may be formed on
the front surface of the outlet main body by outwardly
extending a part of the insertion groove.
A shape of at least one of the plug-receiving portion
and the insertion groove, viewed from the front thereof, may
be partially changed depending on the kinds of a power
supply circuit serving as a power supply source.
In this case, the shape of the insertion 'groove viewed
from the front may be partially changed only when the power
supply circuit is a safety extra low voltage (SELV) circuit.
The plug pins of the plug may include a ground pin,
and the pin-inserting holes of the plug-receiving portion
may include a ground pin inserting hole- into which the
ground pin of the plug is inserted. In this case, the
ground pin inserting hole may be provided offset closer to
the opposite side to the reference side.
In accordance with embodiments of the present
invention, the outlet unit includes the plug-receiving
portion having the substantially quadrangularly shape viewed
from the front surface, the periphery of which is surrounded
by the insertion groove. In the plug-receiving portion, two
pin-inserting holes corresponding to the pin-receiving
pieces for supplying the DC power are arranged along one
side of the plug-receiving portion serving as the reference
side and offset closer to the reference sUde of the plug-
receiving portion. Accordingly, it is possible to easily
recognize an orientation of the plug to be inserted into the
outlet unit. In addition, since the orientation of the plug
to be inserted into the outlet unit is restricted by the
substantially quadrangularly shaped surrounding wall of the
plug to be inserted into the insertion groove provided
around the substantially quadrangularly shaped plug-
receiving portion, it is possible to embody the DC outlet
capable of easily performing position alignment, preventing
the reverse insertion, and being conveniently used. Further,
the plug-receiving portion has the substantially
quadrangularly shape. Accordingly, even when two pin-
inserting holes are arranged offset closer to the reference
side, it is possible to obtain a sufficient insulation
disLance wichout reducing the distance between the pin-
inserting holes, to thereby prevent the DC outlet from being
scaled up.
Besides, an outer peripheral shape of the plug-
receiving portion is changed differently depending on the
kinds of the supply voltage. Accordingly, it is possible to
prevent the wrong insertion of the plug having different
voltage and easily discriminate the kinds of the supply
voltage from the outer peripheral shape of the plug-
receiving portion. In .addition, since an outer peripheral
shape of the plug is changed differently as the outer-
peripheral shape of the plug-receiving portion is changed
differently depending on the kinds o£ the supply .voltage, it
is possible to easily recognize the orientation of the
corresponding plug to be inserted to the DC outlet and
easier insert the plug into the DC outlet. Finally, the
plug-receiving portion has the outer peripheral quadrangular
shape with at least one corner cut. Accordingly, it is
possible to prevent the DC outlet from being scaled up
without protruding the plug-receiving portion to the outer
side of the substantially quadrangular shape.
Brief Description of the Drawings
The objects arid 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 perspective view showing the outer
appearances of a plug and a DC outlet in accordance with a
first embodiment of the present invention before the plug is
connected to the DC outlet;
Figs. 2A to 2C are a front view, a right side view,
and a partial bottom section view, respectively, showing the
DC outlet;
Fig. 3 is a perspective view showing the outer
appearances of a mounting frame and the DC outlet in
accordance with the first embodiment of the present
invention;
Fig. 4 is a perspective view showing the outer
appearance of the plug to be connected to the DC outlet;
Figs. 5A and 5B are front views showing an
installation state of the DC outlet;
Figs. 6A to 6D are front views showing an installation
state of the DC outlet;
Figs. 7A to 7E are front views showing a DC outlet in
accordance with a second embodiment of the present
invention;
Figs. 8A to 8D are front views showing a DC outlet in
accordance with a third embodiment of the present invention;
Fig. 9 is a front view showing an installation state
of the DC outlet;
Fig. 10 shows a structure of a DC power distribution
system employing the DC outlet;
Figs. 11A to 11D are front views showing a DC outlet
corresponding to four supply voltages, i.e., 6, 12, 24 and
48 V, respectively, in accordance with a fourth embodiment
of the present invention;
Fig. 12 is a perspective view showing an outer
appearance of the plug to be connected to the DC outlet of
the fourth embodiment;
Figs. 13A to 13F are front views showing a DC outlet
in accordance with a fifth embodiment of the present
invention, wherein the shapes of a plug-receiving portion
and a receiving groove are changed depending on the kinds of
the supply voltage,-
Fig. 14 is a perspective view showing an outer
appearance of the plug to be connected to the DC outlet of
the fifth embodiment;
Figs. 15A to 15C are a perspective view, a front view
and a bottom view showing a PC outlet in accordance with a
sixth embodiment of the present invention;
Figs. 1€A to 16C are front views showing the DC outlet
of the sixth embodiment, wherein the shapes of a plug-
receiving portion and a receiving groove are changed
depending on the kinds of the supply current;
Figs. 17A to 17D are front views showing the DC outlet
of the sixth embodiment, wherein the shapes of the plug-
receiving portion and the receiving groove are changed
depending on the kinds of the supply voltage;
Figs. 18A and 18B are a perspective view and a front
view showing an outer appearance of the plug to be connected
to the DC outlet' of the sixth embodiment;
Fig. 19A is a perspective view showing the DC outlet
and the plug of the sixth embodiment '' which are to be
connected;
Fig. 19B is a front view of the DC outlet of the sixth
embodiment which explains the case the plug is reversely
connected to the DC outlet;
Figs. 20A to 20D are front views showing installation
states of the DC outlets of the sixth embodiment;
Fig. 21 is a perspective view showing a modification
of the DC outlet of the sixth embodiment;
Fig. 22 is a perspective view showing another
modification of the DC outlet of the sixth embodiment;
Figs. 23A and 23B are perspective view showing still
other modifications of the DC outlet of the sixth
embodiment;
Figs. 24A to 24C are front views showing a DC outlet
in accordance with a seventh embodiment of the present
invention, wherein the shapes of the plug-receiving portion
and the receiving groove are changed depending on the kinds
of the power supply circuit;
Figs. 25A and 25B are perspective views showing outer
appearances of the plugs to be connected to the DC outlets
of the seventh embodiment;
Fig. 26 is a front view showing still another
modification of the DC outlet of the seventh embodiment;
Figs. 27A to 27C are front views showing a DC outlet
in accordance with an eighth embodiment of the present
invention, wherein the shapes of the plug-receiving portion
and the receiving groove are changed depending on the kinds
of the power supply circuit;
Figs. 28A and 28B are front views showing a
modification of the DC outlet of the eighth embodiment;
Fig. 29 is a front view showing an installation state
of the DC outlet of the eighth embodiment;
Figs. 30A and 30B are a perspective view and a front
view showing a DC outlet in accordance with a ninth
embodiment of the present invention; r
Figs. 31A and 31B are a perspective view and a front
view showing an outer appearance of the plug to be connected
to the DC outlet of the ninth embodiment;
Figs. 32A to 32D are front views showing the DC outlet
of the ninth embodiment, wherein the shapes of the plug-
receiving portion and the receiving groove are changed
depending on the kinds of the supply voltage;
Figs. 33A to 33B are front views showing the DC outlet
of the ninth embodiment, wherein the shapes of the plug-
receiving portion and the receiving groove are changed
depending on the kinds of the power supply circuit;
Figs. 34A to 34E are front views showing modifications
of the DC outlet of the ninth embodiment;
Figs. 35A to 35B are front views showing modifications
of the DC outlet of the ninth embodiment;
Fig. 36A and 36B are explanatory views showing a case
where a flat-blade shaped plug pins are inserted into pin-
inserting holes in the DC outlet; and
Figs. 37A to 37D show a socket and a plug for a safety
extra low voltage (SELV) voltage standardized by the IEC
standard, wherein Figs. 37A and 37B are a front view and a
cross sectional view of the socket and Pigs. 37C and 37D arc
a front view and a cross sectional view of the plug.
Detailed Description of the Embodiments
Embodiments of the present invention will now be
described with reference to the accompanying drawings which
form a part hereof.
In the embodiments, a wall-buried DC outlet is taken
for an example. The present invention may be applied to a
an outlet such as an outlet fixed to an electric device, a
code connector body used for extending connection of a code
without being fixed, and a unfixed multi-outlet power strip
and the like.
(First embodiment)
A first embodiment of the present invention will be
described with reference to Figs. 1 to 6D. A DC outlet of
the first embodiment is buried in a construction surface
such as a wall. The DC outlet 1 and a plug 2 that is, e.g.,
detachably connected to the DC outlet 1 constitute a plug
connector for a DC power. Unless otherwise described,
upward, downward, left and right directions of the DC outlet
1 are defined based on Fig. 2A. Fig. 2A shows the front
side of the DC outlet 1 and the right side of Fig. 2B
indicates the rear side of the DC outlet 1.
The DC outlet 1 includes an outlet main body 10 buried
in a construction surface, the outlet main body 10 being
made of a synthetic resin material. The outlet main body 10
includes a substantially rectangular body 11 with a front
side opened and a substantially rectangular-cover 12 with a
rear side opened, which are assembled, together by an
assembling frame 13. The body 11 and the cover 12 are made
of a synthetic resin material, and the assembling frame 13
is made of a metal material.
The outlet main body 10 has a size conforming to
Japanese Industrial Standard (see JIS C 8303). The outlet
main bodies 10 has one module dimension? and three outlet
main bodies can be attached side by side to a mounting frame
for interchanging wring devices of large square boss type
(see JIS C 8375) .
On a front surface of the cover 12, a boss 12a is
forwardly protruded therefrom as a single unit to be fixed
in an opening 54 of a mounting frame 50. A central portion
of the substantially U-shaped assembling frame 13 is mounted
in each of shoulders 12b provided at opposite end sides of
the boss 12a. Opposite end sides of the assembling frame 13
are respectively inserted into engaging recesses 12c and lla
formed at side surfaces of the cover 12 and the body 11, and
substantially V-shaped engaging claws 13c provided at
leading end portions of the opposite end sides of the
assembling frame 13 are respectively expanded to be engaged
with the opposite end portions of the engaging recess lla.
Accordingly, the body 11 and the cover 12 are combined by
the assembling frame 13.
Protrudently provided at an outer peripheral portion
of a central portion of the assembling frame 13 is a pair of
engaging claws 13a capable of being engaged with engaging
openings provided on the mounting frame 50 made of a
synthetic resin material. Further, engaging openings 13b
are provided at a protruding portion forwardly protruding
from an. inner peripheral portion of the central portion of
the assembling frame 13 to be engaged with engaging claws of
a mounting frame (not shown) made of a metal material when
being installed in the mounting frame.
Provided on a front surface of the boss- 12a is an
outlet unit 14 to which the plug 2 is detachably connected.
Specifically, the outlet unit 14 is provided at a central
portion of- the front surface of the boss' 12a. The outlet
unit 14 has a substantially quadrangular shape viewed from
the tront thereof and includes a plug-receiving portion 15
in which two circular pin-inserting holes, 16 are formed? an
insertion groove 17 formed to surround the plug-receiving
portion 15 so as to receive a surrounding wall 23 of the
plug 2; and two pin-receiving pieces 18 for being
respectively engaged with plug pins 22 of the plug 2
inserted into the outlet main body 10 through the pin-
inserting holes IS.
Specifically, the two pin-inserting holes 16 are
provided to correspond to the two (positive and negative)
pin-receiving pieces 18 for supplying a DC power. The pin-
inserting holes 16 are arranged along a side, e.g., an upper
side, in the present embodiment, serving a reference side KL,
of the plug-receiving portion 15 and closer to the upper
side (the reference side KL) of the plug-receiving portion
15 than a lower side thereof opposite to the'reference side
KL.
In addition, a distance between the upper side of the
plug-receiving portion 15 and the pin-inserting holes 16 is
1/2 or less of a distance between the pin-inserting holes 16
and the lower side thereof. Further', it is easily
recognized- that the pin-inserting holes 16 are arranged
closer to the upper side of the plug-receiving portion 15.
Received into the outlet main body 10 are connection
terminals (not shown) of so-called quick connection terminal
structure to be respectively electrically connected to the
pin-receiving pieces 18. A power supply line (not shown) of
a DC power supply is inserted through a line-inserting hole
opened at a rear side of the body 11 to be connected to the
connection terminal. Further, the conventional quick
connection terminal disclosed in the Japanese Patent
Application Publication No. H10-144424, for example, may be
employed as the connection terminals (not shown) of quick
connection terminal structure, and the description and
illustration thereof will be omitted.
Fig. 3 shows the DC outlet 1 and the mounting frame 50
before the DC outlet 1 is mounted in the mounting frame 50
made of a synthetic resin material. The mounting frame 50
has installation pieces 51 at its. longitudinally opposite
ends. Each of the installation pieces 51 includes a long
hole 52 for a box screw; an attachment hole (not shown) for
attachment of a clamping bracket; and a screw hole 53 for a
plate screw.
Three sets of engaging holes (not shown) are formed in
one longitudinal side piece 55, one set being constituted by
two engaging holes, and a longitudinally extending plate
piece 57 is installed hanging down in the other longitudinal
side piece 56. Three engaging holes 59 are formed in the
plate piece 57 in the longitudinal "direction, and a
protruding piece 58 is installed protruding from each of the
engaging holes 59 upwardly.
When the DC outlet l is buried and installed on a
construction surface through the mounting frame 50, the
engaging claws 13a of the assembling frame 13 provided at
one side of the DC outlet 1 are first respectively inserted
into the engaging holes (not shown) provided in the side
piece 55 of the mounting frame 50. Then, 'the engaging holes
13a of the assembling frame 13 provided at the other side of
the DC outlet 1 are respectively inserted into the engaging
holes 59 while being placed on opposite shoulders 58a of the
respective protruding pieces 58. In this way, the outlet
main body 10 is mounted in the mounting frame 50 while
exposing the front surface of the boss 12a through the
opening 54.
Next, a power supply line from a power supply is drawn
into the inside through a burying hole that is opened to the
construction surface and an uncovered central line of the
power supply line is inserted through the line-inserting
hole provided in a rear surface of the body 11 to
electrically connect the power supply line to the terminal.
Moreover, the mounting frame 50 is fixed on the construction
surface by burying a rear portion of the outlet main body 10,
to thereby allow the outlet main body 10 of the DC outlet 1
to be fixed on the construction surface through the mounting
frame 50.
As shown in Fig. 5A, a decoration plate 60 is provided
on a front surface of the mounting frame SO, and the outlet
unit 14 of the DC outlet 1 is exposed through a window
opening 61 formed in the decoration plate 60. Further,
since the outlet main body 10 of the DC outlet 1 may be
formed to have one module dimension, three DC outlets 1 may
be mounted in the mounting frame 50 as shown in Fig. 5B. As
shown in Figs. 6A to 6C, the DC outlet may be mounted in the
mounting frame 50 together with other wiring devices.
Specifically, in Fig. 6A, the DC outlet 1, a TV outlet
3, and a LAN modular outlet 4 are installed together in the
mounting frame 50. In Fig. 6B, the DC outlet 1, the LAN
modular outlet 4, and a phone modular outlet 5 are installed
together in the mounting frame 50. In' Fig. 6C, two DC
outlets 1 and a wiring device 6 such as a pilot lamp are
installed together in the mounting frame 50. Further, in
Fig. SD, an AC outlet 7 formed to have three module
dimension are installed in one of two mounting frames 50,
and three DC outlets 1 formed to have one module dimension
are installed in the other mounting frame,50.
In the meantime, as shown in Fig. 4, the plug 2
connected to the DC outlet 1 includes a horizontally longer
rectangular shaped plug main body 21 made of a synthetic
resin material and having a size that is enough to grip by a
hand. On a front surface (facing the DC outlet) of the plug
main body 21, two circular bar shaped plug pins 22 are
protrudently provided and the rectangularly tubular
surrounding wall 23 is provided to surround the two plug
pins 22. Here, a distance between the front surface of the
plug main body and the leading end of the surrounding wall
23 is set to slightly longer than a distance between the
front surface of the plug main body and the leading ends of
the plug pins 22. In addition, the two plug pins 22 are
arranged along a side (e.g., an upper side) of the
surrounding wall 23 such that a distance between the plug
pins 22 and the upper side of the surrounding wall 23
becomes smaller than a distance between the plug pins 22 and
a lower side of the surrounding wall 23. Meanwhile, a cable
24 from a rear surface of the plug main body 21 is connected
to a load device (hot shown) . Accordingly, when the plug 2
is connected to the DC outlet 1, a DC power is supplied to
the load device through the cable 24.
when the plug 2 is connected to the DC outlet 1, the
plug 2 first approaches the DC outlet 1 'such that the plug
pins 22 are aligned with the pin-insertihg holes 16. Then,
the surrounding wall 23 o£ the plug 2 is inserted into the
insertion groove 17 of the DC outlet 1, and the plug pins 22
are fitted into the pin-inserting holes 16. Thereafter, the
plug 2 continuously reaches a predetermined position to
thereby engage the plug pins 22 with the pin-receiving
pieces 18 electrically and mechanically. In addition, when
the plug pins 22 are engaged to pin-receiving pieces 18, the
front end portion of the surrounding wall 23 has been
inserted into the insertion groove 17. Accordingly, even
when an arc is generated during the engagement of the plug
pins 22, the generated arc is not seen from the outside.
When the plug 2 is disconnected from the DC outlet 1,
the plug 2 is first gripped and pulled out. Then, the plug
pins 22 are disengaged from the pin-receiving pieces 18 and
the pin-inserting holes 16. Thereafter, the surrounding
wall 23 of the plug 2 is separated out from the insertion
groove 17, to thereby disconnect the plug 2 from the DC
outlet 1 easily. In addition, when the plug pins 22 are
disengaged from the pin-receiving pieces 18, the leading end
of the surrounding wall 23 has still been inserted into the
insertion groove 17. Accordingly, even when an arc is
generated during the disengagement of the' plug pins 22, the
generated arc is not seen from the outside".
In the DC outlet 1 of the present embodiment, the
plug-receiving portion 15 to be inserted into the
surrounding wall 23 of the plug 2 has the rectangular shape,
and the two plug pins 22 opened to the plug-receiving
portion 15 are arranged along and closer to the upper side
(reference side) KL of the plug-receiving portion 15 such
that the distance between the plug pins 22 and the upper
side KX, becomes smaller than the distance between the plug
pins 22 and the lower side (opposite to the reference side
KL) of the plug-receiving portion 15. Accordingly, it is
possible to easily recognize an orientation of the plug 2 to
be connected to the outlet unit 14.
Further, the orientation of the plug 2 to be connected
to the outlet unit 14 is restricted by the rectangularly
tubular surrounding wall 23 of the plug 2 to be inserted
into the insertion groove 17 provided around the plug-
receiving portion 15. Accordingly, it is possible to embody
the uc outlet l capable of easily performing position
alignment, preventing the reverse insertion, and being
conveniently used, as compared with a socket of the SE1»V
circuit, standardized by the IEC standard, with a circular .
engaged part.
In addition, in the outlet un£:t 14, since the
insertion groove 17 is merely provided around the plug-
receiving portion 15 to which the pin-inserting holes 16 are
opened without the keyway differently from the socket of
SELV circuit standardized by the IEC standard, it is
possible to simplify the shape of the outlet unit 14 with
satisfactory strength without causing the DC outlet i to be
scaled up.
In case that the plug-receiving portion 15 has a
circular shape viewed from the front thereof, when the two
pin-inserting holes 16 are arranged closer to a side of the
plug-receiving portion 15, the distance; between the pin-
inserting holes 16 becomes closer. Since, however, the
plug-receiving portion 15 has the substantially quadrangular
(e.g., rectangular) shape viewed from th'e front thereof in
the present embodiment, the pin-inserting holes 16 does not
becomes closer even when the pin-inserting holes 16 are
arranged offset closer to the upper side, i.e., the
reference side KL. Accordingly, it is possible to obtain a
satisfactory insulation distance without causing the DC
outlet l to be scaled up.
In the plug-in connection device. of the present
embodiment, flat-blade shaped plug pins may be provided in
the plug 2 instead of the circular bar shaped plug pins 22,
and rectangular pin-inserting holes 16" may be formed in the
plug-receiving portion 15 as shown in Fig. 36A. In this
case, cross section areas of the flat-blade shaped plug pins
are required to be identical to those of the circular bar
shaped plug pins 22. Accordingly, the plug pins have a
narrow width and a horizontally long length. For that
reason, as shown in Fig. 36A, the pin-inserting holes 16"
formed in- the plug-receiving portion 15 also have a
horizontally long length as compared with the circular pin-
inserting holes 16.
When the outlet main body 10 is formed to have one
module dimension, a difference between a longitudinal
dimension (up-down directional dimension) of the pin-
inserting holes 16" and the up-down directional dimension of
the circular pin-inserting holes 16 is small. Accordingly,
although the pin-inserting holes 16" are arranged offset
closer to the upper side of the plug-receiving portion 15 in
the up-down direction thereof with regard' to the central
position of the plug-receiving portion 15, it is difficult
to obtain a large offset amount of the pin-inserting holes
16" and, thus, it is also difficult to recognize whether the
pin-inserting holes 16" are arranged offset closer to the
upper or the lower side of the plug-receiving portion 15.
Further, the pin-inserting holes" 16" are formed
slightly longer than the longitudinal dimension of the flat-
blade shaped plug pins. Accordingly, in case that the
offset amount in the up-down direction of opening positions
of the pin-inserting holes 16" is small, when the plug 2 is
inserted into the DC outlet in the reverse direction, end
portions of the flat-blade shaped plug pins may reversely be
inserted into the pin-inserting holes 16". For that reason,
it. is required to increase the offset amount in the up-down
direction of the opening positions of the pin-inserting
holes 16" as shown in Fig. 36B. This, however, causes the
outlet main body .10 to be scaled up.
On the contrary, since the pin-inserting holes 16 have
the circular shape in the present embodiment, it is possible
to increase the offset amount in the up-down direction of
the opening positions of the pin-inserting holes 16 as
compared with the rectangular pin-inserting holes 16".
Accordingly, it is easy to recognize whether the pin-
inserting holes 16 are arranged offset closer to the upper
or the lower side thereof. Further, when the plug 2 is
inserted into the DC outlet in the reverse orientation, the
plug pins 22 of the plug 2 would not be inserted into the
pin-inserting holes 16.
Meanwhile, the DC outlet l of the,present embodiment
is employed in a DC power distribution system shown in Fig.
10. Fig. 10 shows an example in which the DC power
distribution system is applied to a detached house H.
Alternatively, the DC power distribution system may be
applied to a multi-family attached house or a building.such
as a tenant building.
In the house H, a DC power supply unit 72 for
outputting a DC power; the DC outlets 1, provided at
necessary positions, to which a DC power is supplied through
DC supply lines Wdc; and a plurality of electric devices
(e.g., a refrigerator 80a, a TV 80b, and a phone 80c) that
are operated by the DC power are installed. The DC power is
supplied to the electric devices 80a to, 80c by connecting
outlet plugs of the electric devices 80a to 80c. to the DC
outlets l. Further, DC breakers 73 are respectively
provided between the DC power supply unit 72 and the DC
outlets 1 in order to monitor currents flowing through the
DC supply lines Wdc and restrict or interrupt the power
supply from the DC power supply unit 72 to the DC outlets 1
through the DC supply lines Wdc when detecting an
abnormality.
The DC power supply unit 72 typically converts into a
DC power an AC power supplied from an AC power source AC,
e.g., a commercial power source, outside the house H. In
Fig. 10, the DC power supply unit 72 includes an AC/DC
converter 74 and a control unit 75, and the AC power is
inputted to the AC/DC converter 74 including a switching
power source through a master breaker 71 provided in a power
distributor 70. The converted DC power is inputted to the
respective DC breakers 73 through the control unit 75.
The DC power supply unit 72 further includes a
secondary battery 77 to prepare for a time during which no
power is supplied from the AC power source AC (e.g., the
blackout of the AC power source AC) . A fuel battery 78
and/or a solar battery 76 for generating a DC power may be
employed together in addition to the sec'ondary battery 77.
In this case, with respect to a major power source including
the AC/DC converter 74 for generating a DC power by using an
AC power supplied from the AC power source AC, the solar
battery 76, the secondary battery 77 and/or the fuel battery
78 serve as decentralized power sources. In addition, each
of the solar battery 76, the secondary battery 77 and the
fuel battery 78 includes a circuit unit for controlling an
output voltage. Further, the secondary battery 77 includes
a circuit unit for controlling a charging as well as the
circuit unit for controlling an output voltage.
The electric devices 8 0a to 80c need a plurality of
kinds of voltages depending on device types. For that
reason, the control unit 75 preferably includes a DC/DC
converter for converting a specific voltage supplied from
the major and the decentralized power sources into necessary
voltages to respectively supply the converted voltage to
corresponding DC outlets 1. The supply voltages of the DC
power may adequately be determined depending on the electric
devices and/or the use environment of a building. Here, a
power supply circuit of the power supply source for
supplying a DC power to the DC outlet 1 is provided between
the AC power supply source AC and the DC outlet 1, e.g.,
inside the power distributor 70.
(Second embodiment)
A second embodiment of the present invention will be
described with reference to Fig. 7. In the first embodiment,
the plug-receiving portion 15 has the substantially
quadrangular (rectangular) shape viewed from the front
thereof. on the other hand, in the second embodiment, the
plug receiving portion 15 has the subatantially quadrangular
(rectangular) shape with at least one corner cut depending
on the kinds of the supply voltage, viewed from the front.
Since the confiuration of the second embodiment is
substantially identical to that of the first embodiment
except for the shape of the plug-receiving portion 15, the
components having substantially the same configuration and
function are denoted, by like reference characters and
redundant description thereof will be omitted herein.
There is a plurality of electric devices requiring
supply voltages, e.g., 6, 12, 24, 48 V. In case that a
supply voltage of a DC outlet to be connected to an electric
device is higher than that of the electric device, the
insulation part of a plug of the electric device may be
damaged or the temperature of the plug may be increased. On
the other hand, in case that the supply voltage of the DC
outlet is lower than that of the electric device, the
performance of the electric device may be deteriorated.
The DC outlet 1 of the present embodiment receives,
e.g., four kinds of voltages of DC 6, 12, 24, and 48 V.
Figs. 7A, 7B, 7C, and id show the DC outlets of 6, 12, 24,
and 48 V, respectively. Specifically, in the DC outlet 1 of
6 V, the plug-receiving portion 15 has the substantially
quadrangular (rectangular) shape with an inclined side 15a
formed by obliquely cutting the right lower corner. The
insertion groove 17 also has a shape conforming to the shape
of the plug-receiving portion 17. In addition, in the DC
outlet 1 of 12 V, the plug-receiving portion 15 has the
substantially quadrangular (rectangular) shape with an
inclined side 15a formed by obliquely cutting the left lower
corner. The insertion groove 17 also has a shape conforming
to the shape of the plug-receiving portion; 17.
in the DC outlet 1 of 24 v, the plug-receiving portion
15 has the substantially quadrangular (rectangular) shape
with no inclined side. Finally, in the DC outlet 1 of 48 V,
the plug-receiving portion 15 has the substantially
quadrangular (rectangular) shape with inclined sides 15a
formed by obliquely cutting the right and left lower corners.
The insertion groove 17 also has a shape conforming to the
shape of the plug-receiving portion 17.
As described above, the plug-receiving portion 15 has
the substantially quadrangular (rectangular) shape viewed
from the front in the DC outlet 1 of 24 V, and the plug-
receiving portion 15 has the substantially quadrangular
(rectangular) shape with the inclined side(s) 15a formed by
obliquely cutting at least one of the corners depending on
the kinds of the supply voltage in the DC outlets 1 of 6, 12
and 4 8 v. The shape of the plug-receiving portion 17 has a
different' outer peripheral shape depending on the kinds of
the supply voltage. Accordingly, it is possible to easily
discriminate the kinds of the supply voltage by using the
outer peripheral shape of the plug-receiving portion 15.
In addition, since the plug-receiving portion 15 has
the substantially quadrangular (rectangular) outer
peripheral shape with at least one corner that is obliquely
cut depending on the kinds of the supply voltage, it is
possible to prevent the DC outlets 1 from being scaled up
since the shape of the plug-receiving portion 15 does not
extend from the rectangular shape.
Besides, since the plug-receiving portion 15 has the
different outer peripheral shape depending on the kinds of
the supply voltage and the outer peripheral shape of the
surrounding wall 23 of the plug 2 is changed conforming to
the shape of the plug-receiving portion 15, it is possible
to prevent the plug 2 requiring a specific supply voltage
from being wrongly connected to the DC outlet supplying a
different voltage than the required specific supply voltage
and easily recognize the orientation of the plug 2 to be
connected to the corresponding DC outlet i. Accordingly, it
is possible to more easily insert the plug 2 into the
corresponding DC outlet 1.
In the plug-receiving portion 15 of the present
embodiment, the corner or corners thereof on the opposite
side (lower side) to the upper side to which the pin-
inserting holes 16 are arranged offset closer is or are
obliquely cut depending on the kinds of the supply voltage.
Accordingly, it is possible to obtain a longer distance
between the side with the cut corner or corners and the pin-
inserting holes 16 as compared with a case that the corner
of the upper side to which the pin-inserting holes 16 are
arranged offset closer is obliquely cut' depending on the
kinds of the supply voltage. Therefore, it is possible to
suppress the strength of the plug-receiving portion 15 from
being reduced.
In the present embodiment, the shape of the plug-
receiving portion 15 is changed by cutting the corner(s) of
the lower side of the plug-receiving portion 15 depending on
the kinds of the supply voltage. However, the position and
the number of the cut corner are not limited to those in the
present embodiment. The corner(s) of the reference side KL
(upper side) to which the pin-inserting holes 16 are
arranged offset closer may be cut or the corner (s) of both
the upper side and the lower side may be cut. The shape of
the cut section is also not limited to the present
embodiment. As shown in Fig. 7E, an angular recess 15h may
be formed by angularly cutting the corner of the plug-
receiving portion 15.
(Third embodiment)
A third embodiment of the present invention will be
described with reference to Figs.- 8 and 9. In the DC outlet
1 of the first and the second embodiment, the shape of the
portion thereof engaged with the plug 2 is not changed
depending on kinds of the power supply circuit serving as
the power supply source. However, in the present embodiment,
an identifying extension groove 17d (hereinafter, referred
to as "extending grove 17d" simply) for identifying the
kinds of the power supply circuit is formed by locally
extending the insertion groove 17. Since the configuration
of the third embodiment is substantially identical to that
of the first or the second embodiment except for the
extension groove 17d, the components having substantially
the same configuration and function are denoted by like
reference characters and redundant description thereof will
be omitted herein.
As the kinds of the power supply circuit serving as
the power supply source, a safety extra low voltage (SELV),
an extra low voltage (EL.V) , a functional' extra low voltage
(FELV) circuit and the like are standardized by the IEC
standard. As shown in Figs. 8A to 8D, in the DC outlet 1 of
the SELV circuit, the extension groove 19 is formed at a
central portion of the lower side of the plug-receiving
portion 15 in the right-left direction of the lower side.
Figs. 8A, 8B, 8C and 8D show the DC outlet 1 of 6, 12, 24
and 4 8 V, respectively. As in the second embodiment, the
plug-receiving portion 15 has the substantially quadrangular
shape with at least one of the corners cut depending on the
kinds of the supply voltage, viewed from the front. In the
DC power distribution system shown in Fig. 10, the power
supply circuit for supplying a DC power to the DC outlet 1
is provided between the AC power supply source AC and the DC
outlet l, e.g., inside the power distributor 70.
Since the extension groove 19 is formed by locally
extending the insertion groove 17, it is easer to maintain
the strength of the cover 12 as compared with the case that
a groove formed separately from the insertion groove 17. It
also becomes easer to manufacture the extension groove 19
due to its simple shape. Further, since- the extension
groove 19 is formed at the side opposite to the side (upper
side) to which the pin-inserting holes IS are arranged
offset in the plug-receiving portion 15, it is possible to
obtain a sufficient distance between the extension groove 19
and the pin-inserting holes 16 while suppressing the
strength of the plug-receiving portion 15 from being reduced.
In addition, since the extension groove 19 is formed
by locally extending the insertion groove 17 into the plug-
receiving portion 15, it is possible to make the size of a
front surface of the boss 12a smaller as compared with a
case of extending the insertion groove 17 to a side opposite
to the plug-receiving portion 15, thereby preventing the DC
outlet from being scaled up. The position, shape and number
of the extension groove 19 are not limited to those in the
present embodiment. If the kinds of the power supply
circuit can be identified by using the extension groove 19,
the position, shape and number of the extension groove 19
may be varied.
In the meantime, in the DC outlet 1 of the ELV circuit,
no extension groove 19 is formed as shown in Figs. 7A to 7D.
Accordingly, it is possible to easily discriminate the kinds
of the power supply circuit depending on whether or not
there is the extension groove 19.
In the plug 2 of the SELV circuit, an identifying rib
(not shown), for being engaged with the identifying extension
groove 19 is formed on the inner surface of the surrounding
wall 23. No identifying rib, however, is formed in the plug
2 of the ELV circuit. For that reason, the plug 2 of the
ELV circuit may be connected to both the DC outlets 1 of the
ELV and the SELV circuit. On the other hand, the plug 2 of
the SELV circuit is connected to only the DC outlet 1 of the
SELV circuit.
Meanwhile, since the SELV circuit has a higher
insulation level than that o£ the ELV circuit, a load device
used in the SELV circuit (hereinafter, referred to as "SELV
device") may not require an insulation performance that is
as high as that of a load device used in the ELV circuit
(hereinafter\ referred to as WELV device") and the SELV
device may often have a lower insulation performance than
that of the ELV device. Accordingly, if the SELV device has
the lower insulation performance than that of the ELV device
is used in the ELV circuit having a lower insulation level
than that of the SELV circuit, the SELV device may be
damaged by an electric leakage.
In the present embodiment, since the plug 2 of the
SELV circuit is unable to be connected to the DC outlet 1 of
the ELV circuit while being able to be connected to the DC
outlet 1 of the SELV circuit only, it may be impossible that
the SELV device is used in the ELV circuit. Meanwhile, the
ELV device may be connected to the DC outlet 1 of the SELV
circuit. However, the ELV device has a higher insulation
performance than that of the SELV device and the SELV
circuit has the higher insulation level that "that of the ELV
circuit. Accordingly, if the ELV device is used in the SELV
circuit, the ELV device may not be damaged.
Fig. 9 shows a construction state of the DC outlet 1.
in Fig. 9, two DC outlets 1A and IB of 24"" and 48 v having
the ELV circuit; and one DC outlet 1C of 24 V having the
SELV circuit are installed together in the mounting frame 50.
(Fourth embodiment)
A fourth embodiment of the present invention will be
described with reference to Figs. 11A to 12. In the DC
outlet 1 of the second embodiment, the plug-receiving
portion 15 has the substantially quadrangular shape with at
least one of the corners cut depending on the kinds of the
supply voltage, viewed from the front; ^and the insertion
groove 17 is formed around the periphery of the plug-
receiving portion 15, so that the shape of the insertion
groove 17 is changed depending on the kinds of the supply
voltage. In the present embodiment, the extension groove 19
is formed by extending the insertion groove 17 into the
plug-receiving portion 15, so that the shape of the plug-
receiving portion 15 and the shape of the insertion groove
17 (including the extension groove 19) , as viewed from the
front, are partially changed depending on the kinds of the
supply voltage. Since the structure of the fourth
embodiment is substantially identical to that of the first
embodiment except for forming the extension groove 19, the
components having substantially the same configuration and
function are denoted by like reference characters and
redundant description thereof will be omitted herein.
Figs. 11A to 11D are front views showing the DC outlet
l corresponding to four supply voltages, i.e., 6, 12, 24 and
4 8 v, respectively. In the plug-receiving portion 15, two
pin-inserting holes 16 are arranged offset closer to the
upper side serving as the reference side KL of the plug-
receiving portion 15. In the DC outlet 1 of 6 V, the
extension groove 19 is formed near the left end of the lower
side of the plug-receiving portion 15 as shown in Fig. 11A.
in the DC outlet 1 of 12 V, the extension groove 19 is
formed at a slightly left position with regard to the center
of the lower side of the plug-receiving portion 15 as shown
in Fig. 11B. In the DC outlet 1 of 24* V, the extension
groove 19 is formed at a slightly right position with regard
to the center of the lower side of the plug-receiving
portion IS as shown in Fig. 11C. Finally, in the DC outlet
1 of 48 V, the extension groove 19 is formed near the right
end of the lower side of the plug-receiving portion 15 as
shown in Fig. 11D.
Meanwhile, in the plug 2 to be connected to the DC
output 1, as shown in Fig. 12, a rib 23a for being engaged
with the extension groove 19 is protruded from a bottom
surface of the surrounding wall 23. Accordingly, the plug 2
requiring a voltage is prevented from being wrongly
connected to the DC outlet supplying a different supply
voltage than the required voltage by the rib 23a engaged
with only the corresponding extension groove 19.
As described above, in the present embodiment, by
forming the extension groove 19 extending from the insertion
groove 17 to the plug-receiving portion 15 at different
portions of the lower side of the plug-receiving portion 15
depending on the kinds of the supply voltage so that the
shape of the insertion groove 17 viewed from the front is
partially changed. Accordingly, it becomes easy to maintain
rhe strength of the plug-receiving portion 3 5 as compared
with the case that an extension groove is formed separately
from the insertion groove 17. It also becomes easer to
manufacture the plug-receiving portion Iff1' due to its simple
shape.
In addition, the extension groove- 19 is formed by
locally extending the insertion groove 17 into the plug-
receiving portion 15, the shape of the insertion groove 17
is changed such that the area of the plug-receiving portion
15 becomes smaller as compared with the case that the plug-
receiving portion 15 has the substantially quadrangular
shape viewed from the front. Accordingly, it is possible to
prevent the outlet main body 10 from being scaled up since
the substantially quadrangular shape of the plug-receiving
portion 15 does not extend from the rectangular shape.
Besides, the extension groove 19 is formed at a
position close to the side '(lower side) opposite to the
reference side (upper side) KL of the plug-receiving portion
15 to which the pin-inserting holes are arranged offset.
Accordingly, it is possible to obtain a sufficient distance
between the insertion groove 17 (including the extension
qroove 19) and the pin-inserting holes 16 and suppress the
strength of the plug-receiving portion 15 from being reduced.
(Fifth embodiment)
A fifth embodiment of the present invention will be
described with reference to Figs. 13A and 14. In the DC
outlet 1 of the fourth embodiment, the extension groove 19
is formed by locally extending the insertion groove 17 into
the plug-receiving portion 15, so as to partially change the
shape of the insertion groove 17 (including the extension
groove 19) viewed from the front depending on the kinds of
the supply voltage.
In the present embodiment, an extension groove 20 is
formed on a front surface of the outlet main body 10 (i.e.,
the boss l-2a) by locally extending the insertion groove 17
outwardly, so as to partially change the shapes of the plug-
receiving portion 15 and the insertion groove 17 (including
the extension groove 20, viewed from the front. Since the
configuration of the fourth embodiment^ is substantially
identical to that of the first embodiment except - for forming
the extension groove 20, the components haying substantially
the same configuration and function are denoted by like
reference characters and redundant description thereof will
be omitted herein.
Figs. 13A to 13D are front views showing the DC outlet
1 corresponding to four supply voltages, i.e., 6, 12, 24 and
48 V, respectively. In the plug-receiving portion 15, two
pin-inserting holes 16 are arranged offset closer to the
upper side serving as the reference side KL. In the DC
outlet l of 6 V, as shown in Fig. 13A, the extension groove
20 is extended from a left end portion of a lower outer
periphery of the insertion groove 17 outwardly (downwardly
in Fig. 13A) and a protrusion 15c is protruded from a lower
periphery of the plug-receiving portion 15 into the
extension groove, 20, so that the shape of the insertion
groove 17 is partially changed. In addition, in the DC
outlet 1 of 12 V, as shown in Fig. 13B, the extension groove
20 is extended from a lower side portion at a left outer
periphery of the insertion groove 17 outwardly (to the left
in Fig. 13R) and a protrusion 15c is protruded from a left
periphery of the plug-receiving portion 15 into the
extension groove 20, so that the shape'1 of the insertion
groove 17 is partially changed.
In the DC outlet l of 24 V, as shown in Fig. 13C, the
extension groove 20 is extended from a right end portion of
the lower outer periphery of the insertion groove 17
outwardly (downwardly in Fig. 13C) and a protrusion 15c is
protruded from the lower periphery of the plug-receiving
portion 15 into the extension groove 20, so that the shape
of the . insertion groove 17 is partially changed. In
addition, in the DC outlet 1 of 48 V, as shown in Fig. 13D,
the extension groove 20 is extended from a lower side
portion of the right outer periphery of the insertion groove
17 outwardly (to the right in Fig. 13D) and a protrusion 15c
is protruded from the right periphery of the plug-receiving
portion 15 into the extension groove 20, so "that the shape
of the insertion groove 17 is partially changed.
Moreover, as shown in Fig. 3F, without providing the
protrusion 15c while keeping the plug-receiving portion 15
in the substantially quadrangular (rectangular) shape viewed
from the front, only the extension groove 20 may be formed
so as to partially change the shape of the insertion groove
17 .
Meanwhile, in the plug 2 to be connected to the DC
outlet 1, as shown in Fig. 14, a rib 23b for being engaged
with the extension groove 20 is protruded from the outer
surface of the surrounding wall 23; and an engaging groove
23c for being engaged with the protrusion 15c is formed in
an inner surface of the surrounding wall 23, Accordingly,
the plug 2 requiring a supply voltage is prevented from
being wrongly connected to the DC outlet supplying a
different supply voltage than the required supply voltage by
the rib 23b and the protrusion 15c engaged with only the
corresponding extension groove 20 and the corresponding
t
engaging groove 23c, respectively.
As described above, in the present embodiment, the
extension groove 20 is formed on the front surface of the
outlet main body 10 (i.e., the boss' 12a) by locally
extending the insertion groove 17 outwardly, to thereby
partially change the shapes of the plug-receiving portion 15
and the insertion groove 17 depending on the kinds of the
supply voltage. Further, the shape of the insertion groove
17 is changed depending on the kinds of the supply voltage
such that the area of the plug-receiving portion 15 becomes
larger as compared with the case that the plug-receiving
portion 15 has the substantially quadrangular shape viewed
from the front. Accordingly, it is possible to
satisfactorily maintain the strength of the plug-receiving
portion 15 without causing the area of the plug-receiving
portion 15 to become smaller than that of the substantially
quadrangular shape of the plug-receiving portion 15 even
when the shape of the insertion groove 1*7 is changed.
The position, shape and number of the protrusion 15c
of the plug-receiving portion 15 and those of the extension
groove 20 of the insertion groove 17 are not limited to the
present embodiment. If the kinds of the supply voltage can
be identified by the plug-receiving portion 15 and/or the
insertion groove 17, it may be possible to change at least
one o£ the shapes of the plug-receiving portion 15 and the
insertion groove 17 depending on the kinds of the supply
voltage regardless of the position, shape and number of the
changed portion.
(Sixth embodiment)
Hereinafter, the DC outlet 1 in accordance with a
sixth embodiment of the present invention will be described
v/ith reference to,Figs. 15A to 20D.
In the present embodiment, the shapes of the plug-
receiving portion 15 and the insertion groove 17, viewed
from the front, are partially changed depending on kinds of
the supply current. Since the configuration of the sixth
embodiment is substantially identical to that of the first
embodiment, the components having substantially the same
configuration and function are denoted by like reference
characters and redundant description thereof will be omitted
herein.
Referring to Figs. 15A to 17D, the insertion groove 17
includes a pair of first grooves 17a extending in the up-
down direction Z; a pair of second grooves 17b extending in
the left-right direction Y; and inclined- grooves 17c for
respectively connecting the first grooves 17a to the lower
second groove 17b. The inclined grooves 17c are provided
below the central line LI (indicating half portion of a
length of the up-down direction Z) of ....the plug-receiving
portion 15. Further, the insertion groove 17 includes first
extension grooves 17d continuously upwardly extending from
the lower second groove 17b, the first extension grooves 17d
being provided at a central portion of the left-right
direction Y of the lower second groove 17b.
The plug-receiving portion 15 includes first sides 15f
respectively corresponding to the first grooves 18a; second
sides I5g respectively corresponding to the second grooves
17b; inclined sides 15a respectively corresponding to the
inclined grooves 17c; and recessed portions respectively
corresponding to the first extension grooves 17d. The
inclined sides 15a respectively constitute parts of the
inclined grooves 17c and are respectively provided in
parallel with facing sides l7e facing the inclined sides 15a.
Above the central line LI of the plug-receiving
portion 15, the two of pin-inserting holes 16 are provided
to extend through the plug-receiving portion 15 in the
front-rear direction x. in other words, the upper second
side 15g serves as the reference side KL, and the pin-
inserting holes 16 are arranged offset closer to the
reference side KL than the lower second side 15g.
As shown in Fig. 15C, at a bottom wall Ilia of the
body 11, four line-through holes lib through which
electrical lines are inserted; and two ^manipulation holes
lie. The line-through holes lib and the'manipulation holes
lie serve as through holes extending through the bottom wall
11a in the front-rear direction X. The manipulation holes
lie are used to separate the DC supply lines Wdc from the DC
outlet 1.
The shapes of the plug-receiving portion 15 and the
insertion groove 17 changed depending on the supply current
and the supply voltage will be described with reference to
Figs. 16A to 17D. In Figs. 16A to 16C, the DC outlets 1
for the supply voltage of 48 V and the SEL.V circuit are used
as an example.
There is a plurality of electric devices requiring
supply currents, e.g., 6, 12, and 16 A. in the present
embodiment, the shape of the insertion groove 17 is changed
by forming an indentation in the shape of the plug-receiving
portion 15 viewed from the front, to thereby make the DC
outlets l distinguishable depending on the kinds of the
supply current. In other words, based on the DC outlet 1 of
the supply current of 6 A as shown in Fig. 16A, the
indentation or indentations are provided in the DC outlets 1
or the supply voltages o£ 12 and 16 A.
Specifically, in the DC outlet 1 of the supply current
of 12 A as shown in Fig. 16B, a triangularly shaped second
extension groove 17c' is provided at an upper portion of the
inclined groove 17c by internally extending from the
inclined groove 17c in the left-right direction Y.
Similarly, an indentation 180 constituting two sides of the
triangularly shaped second extension groove 17c' is provided
at a portion of the plug-receiving portion-'15 corresponding
to the second extension groove 17C . Moreover, in the DC
outlet 1 of the supply current of 16A as shown in Fig. 16C,
the second extension groove 17c' and the indentation 180 are
provided at the upper portion of each of the two insertion
grooves 17c. Meanwhile, in case that the inclined groove
17c is not provided in the insertion groove 17, each of the
second extension groove 17c' and the indentation 180 may be
formed to have a substantially quadrangular shape viewed
from the front.
Figs. ISA to 16C shows the DC outlets 1 in the case of
the supply voltage of 48 V, and Figs. 17A to 17D show the DC
outlets in the case of the supply current of 6 A.
Alternatively, the shapes of the insertion groove 17 and the
plug-receiving portion 15 for identifying the supply current
and the supply voltage may be mixed. Specifically, as shown
by dotted lines in Figs. 17A to 17D, the second extension
groove 17c' and the indentation 180 may be respectively
provided at the lower left and/or right corner of the
insertion groove 17 and the plug-rece'iving portion IS.
Accordingly, it is possible to manufacture the DC outlets 1
capable of identifying a plurality of supply voltage and
currents, e.g., the DC outlets of 6 V and 6 A, 6 V and 12 A,
and 6 V and 16 A in the case of the supply voltage of, e.g.,
6 V.
in addition to such identification of the supply
voltages and currents, it is also possible to identify
together whether the DC outlet 1 corresponds to the SELV or
the ELV circuit. Specifically, the first extension groove
17d may be provided in the DC outlet 1 df the SELV circuit
as shown in Figs. 16A to 16C, and the first extension groove
17d is not provided in the DC outlet 1 of-trie ELV circuit as
shown in Figs. 17A to 17D. Accordingly, it is possible to
manufacture two kinds of the DC outlets^ 1, i.e., the DC
outlet l of 6 V and 6 A having the EL.V circuit; and the DC
outlet 1 of 6 V and 6 A having the SELV circuit in the case
of the supply voltage of 5 V and the supply current of 6A,
for example.
Next, a structure of the plug 2 will be described with
reference to Figs. 18A to 19B. .
As shown in Figs. 18A and 18B, the surrounding wall 23
of the plug 2 has a shape that is substantially identical to
that of the insertion groove 17 {see Figs. 19A and 19B) .
Specifically, the surrounding wall 23 has the shape
corresponding to the first groove 17a, the second groove 17b
and the inclined groove 17c of the insertion groove 17; and
a first rib 123a corresponding to the first1" extension groove
I7d, a second rib 123b corresponding to the second extension
groove 17c' are provided in the surrounding wall 23.
As shown in Fig. 18B, the plug pins 22 are provided
above a central line L2 of the up-down direction Z of the
surrounding wall 23. The plug pins 22 are arranged along
the left-right direction Y, and a positive plug pin (left
side in Fig. 18B) and a negative plug pin (right side in Fig.
18B) constitute the plug pins 22. !-
As shown in Fig. 19A, when the plug 2 is connected to
the DC outlet 1, the surrounding wall 23 is first inserted
into the insertion groove 17. Then, the plug pins 22 are
respectively inserted into the pin-inserting holes 16. A
positive pin-inserting hole through which the positive plug
pin is inserted and a negative pin-inserting hole through
which the negative plug pin is inserted constitute the pin-
inserting holes 16.
as shown in Fig. 19B, when the plug 2 is reversely
inserted into the DC outlet 1, the plug pins 22 are arranged
below the central line LI (see Fig. 15B) of the plug-
receiving portion 15. Accordingly, the plug pins 22 are
brought into contact with a front surface 15e of the plug-
receiving portion 15, thereby making it impossible to
reversely insert the plug 2 into the DC outlet 1.
in other words, when the plug 2 is reversely inserted
into the DC outlet 1, the plug pins 22 are positioned
separately from the pin-inserting holes 16 in the up-down
direction 2. Accordingly, such reverse insertion can be
prevented reliably.
Specifically, in this case, the second rib 123b is
misaligned with the second extension groove 17c' . In other
words, the second rib 23b is brought into "contact with the
front surface I5e of the surrounding wall, thereby making it
impossible to reversely insert the surrounding wall 23 into
the insertion groove 17. Accordingly, the reverse insertion
of the surrounding wall 23 into the insertion groove 17 can
be prevented.
Next, various arrangements of the DC outlet 1 will be
described with reference to Figs. 20A and 20B.
As shown in Fig. 20A, in a state that the DC outlet 1
is mounted in the mounting frame 50, the decoration frame 60
is attached to the mounting frame 50 from'the front thereof.
The window opening 61 of one module dimension is formed in
the decoration plate 60 to expose the front surface of the
cover 12.
Since the size of the DC outlet 1 is one module
dimension, the DC outlet 1 and other wiring devices of one
or twd module dimensions standardized by the Japanese
Industrial standard are mounted together in the mounting
frame 50. In other words, the DC outlet 1 and the wiring
devices are mounted together in the mounting frame 50.
A window opening 62 of three module dimensions is
formed in the decoration plate 60. For example, the DC
outlets 1 of the supply voltage of 48 V which have different
shapes to identify the supply current are provided as shown
in Fig. 2OB. For another example, the DC outlet 1 of the
supply current of 6 A which have different shapes to
identify the supply voltage are provided as shown in fig.
20C. For still another example, the DC outlet 1, a coaxial
cable outlet 33 and a phone modular outlet 34 are shown in
Fig. 20D. The wiring devices are not limited to the coaxial
cable outlet 33 and the phone modular outlet 34. For
example, an AC outlet and/or a LAN modular outlet may be
used. ¦>-¦
The effects of the DC outlet 1 in accordance with the
present embodiment will be described as follows.
(1) In the present embodiment, the second extension
groove 17c is provided in the receiving grove 17 depending
on the kinds of the supply current. Accordingly, it is
possible to provide the DC outlet 1 having a shape that is
changed to identify the kinds of the ¦ supply current.
Further, since the second extension groove 1-7C is provided
in the insertion groove 17, it is possible to obtain a
common shape of the plug pins 22 as compared with a case the
shape of the pin-inserting hole is changed to identify a
supply current. *
If the shape of the plug pins 22 is*changed, the shape
of the pin-receiving pieces 18 is required to be changed to
conform to the shape of the plug pins 22. Since, however,
. the shape of the plug pins 22 is not changed in the present
embodiment, it is also possible to obtain a common shape of
the pin-receiving pieces 18 regardless of the kinds of the
supply voltage. Accordingly, it is possible to discriminate
the kinds of supply voltage by changing the shape of the
cover 12 only.
(2) In the present embodiment, the second extension
groove 17c' is provided below the central line LI.
Accordingly, since it is possible to obtain the larger
distance between the second extension groove 17c' and the
pin-inserting grooves 16 as compared with the case that the
second extension groove 17c' is provided above the central
line LI, it is possible to improve the strength of the plug-
receiving portion 15. Therefore, it is possible to suppress
the plug-receiving portion 15 from being damaged when the
plug 2 is inserted into and separated from the DC outlet 1.
(3) In the present embodiment, since the second
extension groove 17c' is provided below the central line LI,
the second rib 123b of the plug 2 is misaligned with the
second extension groove 17C when the piug 2 is reversely
inserted into the DC outlet 1. In other; words, the second
rib 123b is brought into contact with the front surface lSe
of the plug-receiving portion 15 and, thus, the second rib
2 3b is suppressed from being reversely inserted in the
second extension groove 17c'. Accordingly, the reverse
insertion of the surrounding wall 23 into the insertion
groove 17 can be prevented.
(4> In the present embodiment, the second extension
groove 17c' is formed by extending the insertion groove 17.
Accordingly, it is possible to suppress -the cover 12 from
being scaled up and the strength of the plug-receiving.
portion 15 from being deteriorated as compared with the case
that the second extension groove 17c' is formed separately
from the insertion groove 17. The same can be applied to
the first extension groove 17d.
(Modifications)
The DC output 1 of the present embodiment may be
modified as follows without being limited to the present
embodiments. Further, the modifications may"be Individually
realized or selectively combined.
Although the present invention is applied to the DC
outlet l in the present embodiment, it may be applied to an
AC outlet. Moreover, the pin-inserting holes 16 are
arranged above the central line Ll in the'present embodiment.
The pin-inserting holes may alternatively be arranged below
the central line Ll or at the same position as the central
line Ll.
Although the inclined groove 17c and the inclined side
15a are provided below the central line Ll in the present
embodiment, the inclined groove 17c and/or the inclined side
15a may be"provided above the central line Ll or at the same
position as the central line Ll. In case that the inclined
groove 17c and the inclined side 15a may be provided above
the central line Ll, the inclined groove 17c and the
inclined side 15a are inclined toward - the upper second
groove 17b and the upper second side l5g, .respectively.
Although the indentation 180 and the- second extension
groove 17c' for identifying the kinds of the supply current
are provided below the central line Ll in the present
embodiment, the indentation 180 and/or the second extension
groove 17c' may be provided above the central line LI or at
the same position as the central line LI. In case that the
indentation 180 and the second extension groove 17C are
provided* at the same position as the central line LI, each
of the indentation 180 and the second extension groove 17c'
has a substantially quadrangular shape, viewed from the
front, in case the indentation 180 and the second extension
groove 17c' are provided above the central line LI, the
indentation 180 and the second extension groove 17C are
extended from the upper second side 15g and the upper second
groove 17c, respectively.
Although the second extension groove 17c' is formed to
extend toward the plug-receiving portion 15 in the present
embodiment, the second extension groove 17C is not limited
thereto. Alternatively, the second extension groove 17c'
may be formed to outwardly extend in, e.g., the upper, the
lower, or the left and right direction other than the
insertion groove 17. The same can be applied to the first
extension groove 17d. -'
Although only the pin-inserting holes 16 are provided
in the plug-receiving portion 15 in the present embodiment,
a ground pin inserting hole l€a may be further provided in
addition to the pin-inserting holes 16 as shown in Fig. 21.
In this case, the ground pin inserting hole 16a is provided
at a central portion of the left-right direction-Y below the
central line LI. In such configuration, three pin-receiving
pieces 18 in total are provided to correspond to the two
pin-inserting holes 16 and one ground pin inserting hole 16a.
Although each of the insertion groove 17 and the plug-
receiving portion 15 has the substantially quadrangular
shape with two corners cut, viewed from the front, in the
present embodiment, each shape of the insertion groove 17
and the plug-receiving portion 15 is not limited thereto.
For example, as shown in Fig. 21, each of the insertion
groove n and the plug-receiving portion 15 may be formed to
have a substantially quadrangular shape without the inclined
groove 17c. and the inclined side 15a. Further, the shapes
viewed from the front of the insertion groove 17 and the
plug-receiving portion 15 may be a ring shape and a circular
shape, respectively, without being limited to the
substantially quadrangular shape. With such configuration,
it is possible to obtain a similar effect to the effect (1)
of the present embodiment.
Although the DC outlet 1 is buried in a wall in the
above embodiments, the DC outlet 1 is not limited to the
above embodiments. For example, the DC outlet 1 may be
applied to a multi-outlet power strip 40 as shown in Fig. 22.
As shown in Fig. 22.
Although the DC outlet 1 is formed to have one module
dimension in the above embodiments, the DC outlet 1 may be
formed to have two module dimension as shown in Fig. 23A or
three module dimension as shown in Fig. 23B.
Although the insertion groove 17 has the rectangular
shape having the longer side in the left-right direction Y
and the shorter side in the up-down direction Z, viewed from
the front, in the above embodiments, the shape of the
insertion groove 17 is not limited to the above embodiments.
The insertion groove 17 may have a square shape having the
same length in the left-right direction Y and the up-down
direction Z, viewed from the front.
(Seventh embodiment)
A seventh embodiment of the present invention will be
described with reference to Figs. 24A to 26. In the DC
outlet 1 of the third embodiment, the extension groove 19 is
formed by extending from the insertion groove 17 toward the
plug-receiving portion 15 to differently change the shape of
the insertion groove 17 depending on the kinds of the power
supply circuit. In the DC outlet 1 of the present
embodiment, the extension groove 20 is formed by externally
extending from the insertion groove 17 in a front surface of
the outlet main body (i.e., the boss 12a),and the
protrusion 15c is formed by protruding from a periphery of
the plug-receiving portion 15 toward the extension groove 20,
so as to change the shape of the insertion groove 17
(including the extension groove 20)differently depending on
the kinds of the power supply circuit. Since the structure
of the seventh embodiment is substantially identical to that
of the third embodiment except for the extension groove 20
and the protrusion 15c, the components having substantially
the same configuration and function are denoted by like
reference characters and redundant description thereof will
be omitted herein.
As the power supply circuit used for the DC outlet 1
of the present embodiment, there are an ELV circuit and an
SELV circuit standardized by the IEC standard. The shape of
the insertion groove 17 (including the extension groove 20)
is changed differently depending on the kinds of the power
supply circuit. Pigs. 24A and 24B are front views showing
the dc outlet 1 of the SELV circuit and the ELV circuit,
respectively.
in the DC outlet 1 of SELV circuit, the extension
groove 20 is formed by extending from a lower left portion
of the insertion groove 17 toward an outside (e.g., a lower
side in Fig. 24A);and the protrusion 15c is formed by
protruding toward the extension groove 20 from a left
portion of a lower periphery of the plug-receiving portion
15. Moreover, in the DC outlet 1 of ELV circuit, the
extension groove 20 is formed by extending from a lower
right portion of the insertion groove 17 toward an outside
(e.g., a lower side in Fig. 24B) ; and the. protrusion 15c is
formed by protruding toward, the extension groove 20 from a
right portion of the lower periphery of the plug-receiving
portion 15.
Alternatively, as shown in Fig. 24C,' the shape of the
insertion groove 17 may be changed differently depending on
the kinds of the power supply circuit by providing the plug-
receiving portion IS having a substantially quadrangular
shape viewed from the front and forming the extension groove
20 only.
Figs. 25A and 25B show the plugs 2 of the selv circuit
and the ELV circuit, respectively, to be connected to the DC
outlet 1. As shown in Fig. 25A, in the plug 2 of the SELV
circuit, a rib 26 to be engaged with the extension groove 20
is protrudently formed at a portion of a peripheral surface
(a right portion of an outer surface of a lower wall) of the
surrounding wall 23 to correspond to the extension groove 20
provided in the DC outlet 1 of the SELV circuit; and an
inserting groove 27 to be engaged with the protrusion 15c is
protrudently formed at a portion of an inner peripheral
surface (a right portion, of an inner surface of the lower
wall) of the surrounding wall 23 to correspond to the
protrusion 15c provided in the DC outlet 1 of the SELV
circuit.
Moreover, as shown in Fig. 25B, in, the plug 2 of the
ELV circuit, the rib 26 to be engaged with the extension
groove 20 is protrudently formed at a portion of a
peripheral surface (a left portion of an outer surface of a
lower wall) of the surrounding wall 23 to correspond to the
extension groove 20 provided in the DC outlet l of the ELV
circuit; and the inserting groove 27 to be engaged with the
protrusion 15c is protrudently formed at a portion of an
inner peripheral surface (a left portion of an inner surface
of the lower wall) of the surrounding wall 23 to correspond
to the protrusion 15c provided in the DC outlet 1 of the ELV
circuit.
In this way, the shape of the insertion groove 17
including the extension groove 20 is partially changed
depending on the kinds (the SELV or the ELV circuit) of the
power supply circuit. Accordingly, it is possible to easily
discriminate the kinds of the power supply circuit from the
difference of the shapes of the insertion groove 17 viewed
from the front.
Further, as described above, positions of the
extension groove 20 and the protrusion 15c in the DC outlet
1 of the SELV are different from those of the extension
groove 20 and the protrusion 15c in the EC outlet 1 of the
ELV circuits; and the rib 26 and the inserting groove 27 to
be respectively engaged with the extension groove 20 and the
protrusion 15c in each of the plugs 2 of the SELV circuit
and the ELV circuit.
Accordingly, the plugs 2 of the SELV circuit and the
ELV circuit are respectively connected to the DC outlets of
the SELV circuit and the ELV circuit without reverse
connection. For that reason, it is possible to safely use
an SELV device without a case that the SELV device requiring
a lower insulation performance than that of an ELV device is
used in the ELV circuit having a lower insulation level than
that of the SELV circuit.
Further, since the extension groove 20 is formed by
externally extending from the insertion groove 17 to change
the shape of the insertion groove 17 differently depending
on the kinds of the power supply circuit in the present
embodiment, it is possible to maintain the strength of the
plug-receiving portion 15 without reduction of the area of
the front surface of the plug-receiving portion 15.
In the present embodiment, the shape of the insertion
groove 17 viewed from the front is changed differently
depending on the kinds of the power supply circuit such that-
the area of the plug-receiving portion is is increased as
compared, with the plug-receiving portion 15 has the
substantially quadrangular shape viewed from the front
thereof. Accordingly, it is possible to suppress the
strength of the plug-receiving portion 15 from being
deteriorated as compared with a case that the shape of the
groove 17 is changed such that the area of the plug-
receiving portion 15 is decreased.
In the present embodiment, the extension groove 20 is
formed by extending from the lower portion of the insertion
groove 17 toward the outside {the lower side in Figs. 24A to
24C) . However, the position, the shape and the number of
the extension groove 20 are not limited to the present
embodiment. For example, as shown in Fig. 26, the extension
groove 20 may be formed by extending from a right portion of
the insertion groove 17 toward to an outside (a right side
in Fig. 26) and the protrusion 15c may be formed by
protruding from a right periphery of the plug-receiving
portion 15 toward the extension groove 20.
In the present embodiment, the extending groove 20 and
the protrusion 15c are formed in both the DC outlets 1 of
the SELV and ELV circuit. However, the extending groove 20
and the protrusion 15c may be formed in the DC outlet 1 of
the SELV circuit only, and the insertion groove 17 having a
substantially quadrangular ring shape vie'wed from the front
thereof may be provided in the DC outlet 1 of the ELV
circuit.
(Eighth embodiment)
-The DC outlet 1 of an eighth embodiment will be
described with reference to Figs. 27A to 29. In the first
and the second embodiment, the extension grooves 19 and 20
are formed'by extending from the extension groove 17 ao as
to partially change the shape of the insertion groove 17.
In the present embodiment, the shape of the insertion groove
17 viewed from the front is changed differently depending on
the kinds of the power supply circuit sudh that the area of
the plug-receiving portion 15 is decreased as compared with
the plug-receiving portion 15 has a substantially
quadrangular shape viewed from the front. Since the
configuration of the seventh embodiment is substantially
identical to that of the seventh embodiment except for the
shape of the insertion groove 17, the components having
substantially the same configuration and function are
denoted by like reference characters and redundant
description thereof will be omitted herein.
Figs. 27A and 27B are front views showing the DC
outlet 1 of the SELV circuit and the ELV circuit,
respectively. In the DC outlet 1 of the ELV circuit, as
shown in Fig. 27B, the plug-receiving portion 15 has the
substantially quadrangular (rectangular) shape viewed from
the front; and an outer peripheral shape of the insertion
groove 17 is similar to an inner peripheral shape thereof
(an outer peripheral shape of the plug-receiving portion 15).
Moreover, in the DC outlet 1 of the SELV circuit, as shown
in Fig. 27A, the inclined side 15a is formed by obliquely
cutting a lower right corner of the insertion groove 17 (the
plug-receiving portion 15) / and the outer peripheral shape
of the insertion groove 17 is similar to the inner
peripheral shape thereof.
Fig. 29 shows an example of the installation of the DC
outlet 1, where one DC outlet 1 of the SELV circuit and two
dc outlets l of the elv circuit are installed in the
decoration frame 50. Meanwhile, in the plugs 2 of the SELV
circuit and the ELV circuit to be connected to the
corresponding DC outlets 1 of the present"" embodiment, the
shape of the surrounding wall 23 to be engaged with the
insertion groove 17 is changed to conform to the shape of
the insertion groove 17 of the corresponding DC outlet 1.
As described above, in the DC outlet l of the ELV
circuit, the plug-receiving portion 15 has the substantially
quadrangular (rectangular) shape viewed from the front and
the shape of the insertion groove 17 that surrounds the
plug-receiving portion 15 is kept unchanged. On the
contrary, in the DC outlet 1 of the SELV circuit, the shape
of the insertion groove 17 is changed such that the area of
the plug-receiving portion 15 is decreased as compared with
the DC outlet 1 of the ELV circuit.
Accordingly, the plug 2 of the ELV circuit is
connected to the DC outlet of the ELV circuit, while the
plug 2 of the SELV circuit is connected to the DC outlet of
the SELV circuit only without being connected to the DC
outlet of the ELV circuit due to the interference between
the surrounding wall 23 and the lower right corner of the
plug-receiving portion 15. Therefore, it- is possible to
safely use an SELV device while preventing the SELV device
requiring a lower insulation performance than that of an ELV
device from being used in the ELV circuit having a lower
insulation level than that of the SELV circuit.
Moreover, in the present embodiment, the shape of the
insertion groove 17 is changed differently depending on the
kinds of the power supply circuit by obliquely cutting at
least one of four corners of the insertion groove 17.
Accordingly, it is possible to easily recognize both the
shape difference of the insertion groove 17 and/or the plug-
receiving portion 15 arid the orientation of the plug 2 to be
inserted into the corresponding DC outlet 1. When the
corner of the insertion groove 17 is cut,, the shape of the
insertion groove 17 is partially changed by obliquely
cutting the corner in the present embodiment and, however,
the corner may be cut into any shape. For'example, as shown
in Fig. 27C, the corner may substantially angularly be cut
to form an angular recess ISh.
Besides, since the lower right corner of the insertion
groove 17 is cut and the two pin-inserting holes 16 are
arranged offset closer to the reference side (the upper
side) opposite to the lower side of the insertion groove 17,
it is possible to obtain a sufficient distance between the
insertion groove 17 and the pin-inserting holes 16, to
thereby suppress the strength of the plug-receiving portion
15 from being deteriorated.
Although the lower right corner ot the insertion
groove 17 is obliquely cut to change the shape of the
insertion groove 17 in the present embodiment, other corner
than the lower right corner may be cut. The shape of the
insertion groove 17 may be changed by cutting the corner(s)
on the reference side (the upper side) to which the pin-
inserting holes 16 being arranged offset closer; or by
cutting both left upper and the left lower corners to form
the inclined sides 15a.
In the DC outlet 1 shown in Figs'; 27A to 28A, the
shape of the insertion groove 17 viewed from the front is
changed by cutting at least one corner of the insertion
groove 17; and the outer peripheral shape' of the insertion
groove 17 is similar tn the inner peripheral shape of the
insertion groove 17. On the other hand, as shown in Fig.
28B, only the inner peripheral shape of the insertion groove
17 may be changed by cutting the corner of the plug-
receiving portion 15 while keeping the outer peripheral
shape of the insertion groove 17 in -the substantially
quadrangular shape. This makes it easier to recognize the
shape difference of the front surface of the plug-receiving
portion 15 and the shape of the insertion groove 17.
(Ninth embodiment)
In the above embodiment, only the pin-inserting holes
16 into which the plug pins 22 of the plug 2 are inserted
are provided in the plug-receiving portion 15. In a ninth
embodiment of the present invention, the ground pin
inserting hole 16a is further provided in addition to the
pin-inserting holes 16 as shown in Figs. 30A and 30B. The
ground pin inserting hole 16a is provided at a central
portion of the left-right direction Y below the central line
Ll. in such configuration, three pin-receiving pieces 18 in
total are provided to correspond to the two pin-inserting
holes 16 and one ground pin inserting hole 16a.
Specifically, referring to Figs. 30A and 30B, pin
holes 160 includes the two pin-inserting holes 16 arranged
along the reference side KL serving as one side of the plug-
receiving "portion 15 extending in the left-right direction Y,
i.e., an upper side of the plug-receiving portion 15; and
one ground pin inserting hole 16a provided at an offset
position closer to the opposite side to the reference side
kl in the up-down direction z than the pin-inserting holes
16. in other words, the ground pin inserting hole 16a is
provided below the pin-inserting holes 16 in the up-down
direction Z.
As shown in Fig. 30B, the pin inserting holes 16 are
provided at an offset position closer to the reference side
kl than the opposite side of the plug-receiving portion 15.
In other words, the pin-inserting holes 16 are provided
above the central point C1 (i.e., the intersection point of
diagonal (dashed dotted) lines from each corner) of the
plug-receiving portion 15 in the up-down direction Z; and at
opposite sides, respectively, in the left-right direction Y
with regard to the central point C1. EspeC1ally, lower end
portions 16' in the up-down direction Z of .the pin-inserting
holes 16 are arranged on the side of closer to the reference
side KL above the (dashed double-dotted) central line Ll
including the central point C1 or above the central line Ll.
The ground pin inserting hole 16a is provided below
the central point C1 in the up-down direction Z and at a
central portion of the two pin-inserting holes 16 in the
left-right direction Y. In other words, the ground pin
inserting hole 16a is provided at a position corresponding
to the central point C1 in the up-down direction Z.
EspeC1ally, an upper end portion 16a' of the ground pin-
inserting hole 16a is provided below the central line L1.
Next, the configuration of the plug 2 of the present
embodiment will be described with reference to Figs. 31A and
31B.
"As shown in Fig. 31A, plug pins 220 includes the plug
pins 22 arranged along one side of an outlet faC1ng surface
in the left-right direction of the Figs. 31A and 31B; and
one ground'pin 22a provided below the plug pins 22.
The plug pine 22 are provided ouch that their leading
ends are located backwardly of the leading end of the
surrounding wall 23. The ground pin 22a is provided such
that its leading end is located forwardly of the leading end
of the surrounding wall 23.
As shown in Fig. 31B, the plug pins 22 are provided
above the central point C2 (i.e., the intersection point of
diagonal (dashed dotted) lines from each corner) of the
surrounding wall 23 in the up-down direction; and at
opposite sides, respectively, in the left-right direction
with regard to the central point C2. EspeC1ally, lower end
portions 22' in the up-down direction of the plug pins 22
are arranged above the (dashed double-dotted) central line
L2 including the central point C2.
The ground pin 22a is provided below the central point
C2 in the up-down direction and at a central portion of the
two plug pins 22 in the left-right direction (i.e., at a
position corresponding to the central point C2 in the up-
down direction). EspeC1ally, an upper end portion 22a' of
the ground pin 22a is provided below the central line L2.
Figs. 32A to 32D show examples of the shape of the
insertion groove 17 that is changed depending on the kinds
of the supply voltage, and Figs. 33A and 33B show examples
of the shape of the insertion groove 17 that is changed
depending on the kinds of the power supply C1rcuit. Since
the shape of the insertion groove 17 that is changed
depending on the kinds of the supply voltage and the power
supply C1rcuit has already been described in the above
embodiments, redundant description thereof will be omitted
in the present embodiment.
Although an extension groove 17i is provided at the
lower left corner of the insertion groove 17 in Fig. 33A,
the position of the extension groove 17i- is not limited
thereto. For example, as shown in Fig. 3'4A, the extension
groove 17i may be provided at the lower right corner of the
insertion groove 17.
The extension groove 17i may be provided at any one of
the four corners of the insertion groove 17 without being
limited to the lower left and right corners of the insertion
groove 17.
Further, the extension groove 17i is provided in the
plug-receiving portion 15 in the present embodiment, but is
not limited thereto. For example, the extension groove 17i
may be provided to extend from the lower side of the
insertion groove 17 downwardly as shown in Fig. 34B or to
extend from the upper side of the insertion groove 17
upwardly as shown in Fig. 34C. Alternatively, the extension
groove 17i may be provided to extend from the left side of
the insertion groove 17 to the left as shown in Fig. 34D or
to extend from the right side of the insertion groove 17 to
the right as shown in Fig. 34E.
In the present embodiment, the inclined groove 17c is
provided at one corner or both corners of the lower side of
the insertion groove 17 to identify the kinds of the supply
voltage of the DC outlet 1. However, such configuration for
identifying the kinds of the supply voltage is not limited
thereto. If the shape of the insertion groove 17 is changed
such that the insertion groove 17 can be inserted into the
surrounding wall 23 of the plug 2 only when the supply
voltage of the plug 2 corresponds to the voltage supplied
from the DC outlet 1, it is suffiC1ent to use the shape of
the insertion groove 17.
Accordingly, a step-shaped recess 17h may be provided
by cutting one corner of the insertion groove' 17 as shown in
Fig. 35A, for example. Further, as shown in Fig. 35B, the
extension groove 20 may be provided by protruding a part of
the insertion groove 17 outwardly. , Meanwhile, the
surrounding wall 23 of the plug 2 is formed to have the same
shape as that of the insertion groove 17, viewed from the
front.
Although the inclined groove 17c is provided at the
lower side of the insertion groove 17 in the present
embodiment, the inclined groove 17c may be provided at the
upper side .of the insertion groove 17.
In the present embodiment, the lower end portion 16'
of the pin-inserting holes 16 is provided above the central
point C1 of the plug-receiving portion 15. However, the
position of the lower end portion 16' is not limited thereto.
The lower end portion 16' may be provided such that the plug
pins 22 arc not inserted into the pin-inserting holes 16
when the plug 2 is reversely inserted into the DC outlet 1.
Accordingly, the lower end portion 16' may be provided at a
substantially same position as that of the central point C1.
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 modifications
may be made without departing from the scope of the
invention as defined in the following claims.
We Claim:
1. A direct current (DC) outlet to which a plug is
adapted to be connected to supply a DC power to the plug,
the plug including a plurality of plug pins having a
C1rcular bar shape; and a substantially quadrangular-shaped
surrounding wall for surrounding the plug pins, the DC
outlet comprising:
an outlet main body having an outlet unit to which the
plug is adapted to be connected, the outlet unit being
provided in a front surface of the outlet main body,
wherein the outlet unit includes a plug-receiving
portion having a plurality of pin-inserting holes into which
the plug pins of the plug are inserted, the plug-receiving
portion having a substantially quadrangular shape viewed
from the front thereof; an insertion groove formed to
surround a periphery of the plug-receiving portion, the
insertion groove being adapted to receive the surrounding
wall of the plug; and pin-receiving pieces for being
connected with the plug pins that are respectively inserted
through the pin-receiving holes,
wherein two of the pin-receiving holes corresponding
to the pin-receiving pieces for supplying a DC power are
arranged along one side of the plug-receiving portion
serving as a reference side and offset closer to the
reference side than an opposite side to the reference side.
2. The DC outlet of claim 1, wherein a shape of at least
one of the plug-receiving portion and the, insertion groove,
viewed from the front thereof, is partially changed
depending on the kinds of a supply voltage or a supply
current.
3. The DC outlet of claim 2, wherein the shape of the
insertion groove viewed from the front is changed such that
an area of the plug-receiving portion is decreased as
compared with a case that the plug-receiving portion has the
substantially quadrangular shape viewed from the front.
4. The DC outlet of claim 3, wherein the shape of the
insertion groove viewed from the front is changed
differently depending on the kinds of the supply voltage or
the supply current by cutting at least one corner of the
substantially quadrangular shape of the plug-receiving
portion depending on the kinds of the supply voltage or the
supply current, and forming the insertion groove along an
outer periphery of the plug-receiving portion:
b. The DC outlet of claim 2, wherein a portion of the
insertion groove whose shape is changed depending on the
kinds of the supply voltage or the supply current is closer
to the opposite side to the reference" side than the
reference side.
6. The DC outlet of claim 2, wherein the shape of the
insertion groove viewed from the front is changed such that
an area of the plug-receiving portion is increased as
compared with a case that the plug-receiving portion has the
substantially quadrangular shape viewed from the front.
7. The DC outlet of claim 2 or 4, wherein the shape of
the insertion groove viewed from the front is partially
changed by forming an extension groove extending from the
insertion groove.
8. The DC outlet of claim 7, wherein the extension groove
is formed by extending a part of the insertion groove into
the plug-receiving portion.
9. The DC outlet of claim 7, wherein the extension groove
is provided closer to the opposite side to the reference
side of the plug-receiving portion than the reference side.
10. The DC outlet of claim 7, wherein the extension groove
is formed on the front surface of the outlet main body by
outwardly extending a part of the insertion groove.
11. The DC outlet of claim 1, wherein a shape of at least
one of the plug-receiving portion and the insertion groove,
viewed from the front thereof, is partially changed
depending on the kinds of a power supply C1rcuit serving as
a power supply source.
12. The DC outlet of claim 11, wherein the shape of the
insertion groove viewed from the front is changed such that
an area of the plug-receiving portion is decreased as
compared with a case that the plug-receiving portion has the
substantially quadrangular shape viewed from the front.
13. The DC outlet of claim 12, wherein the shape of the
insertion groove viewed from the front is changed
differently depending on the kinds of the power supply
C1rcuit by cutting at least one corner of the substantially
quadrangular shape of the plug-receiving portion depending
on the kinds of the power supply C1rcuit, viewed from the
front, and forming the insertion groove along an outer
periphery of the plug-receiving portion.
14. The DC outlet of claim 11, wherein a portion of the
insertion groove whose shape is changed depending on the
kinds of the power supply C1rcuit is closer to the opposite
side to the reference side than the reference side.
15. The DC outlet of claim 11, wherein the shape of the
insertion groove viewed from the front is changed such that
an area of the plug-receiving portion is increased as
compared with a case that the plug-receiving portion has the
substantially quadrangular shape viewed from the front.
16. The DC outlet of claim 11 or 13, wherein the shape of
the insertion groove viewed from the front is partially
changed by forming an extension groove extending from the
insertion groove.
17. The DC outlet of claim 16, wherein the extension
groove is formed by extending a part of the insertion groove
into the plug-receiving portion.
18. The DC outlet of claim 16, wherein the extension
groove is provided closer to the opposite side to the
reference side of the plug-receiving portion than the
reference side.
19. The DC outlet of claim 16, wherein the extension
groove is formed on the front surface of the outlet main
body by outwardly extending the insertion,groove.
20. The DC outlet of claim 11, wherein the shape of the
insertion groove viewed from the front is partially changed
only when the power supply C1rcuit is a safety extra low
voltage (SELV) C1rcuit.
21. The DC outlet of claim 1, wherein the plug pins of the
plug include a ground pin, and the pin-inserting holes of
the plug-receiving portion include a ground pin inserting
hole into which the ground pin of the plug is inserted.
22. The DC outlet of claim 21, wherein the ground pin
inserting hole is provided offset closer to the opposite
side to the reference side.

ABSTRACT

A plug,adapted to be connected to a direct current
(DC) outlet for supplying a DC power thereto, includes a
plurality of round bar- shaped plug pins which promides from a
front surface of a plug main body, and a surrounding wall which
promides from the front surface of the plug main body to surround
the plug pins. The plug pins are adapted to be connected
the pin-receiving pieces through pin insertion holes of the DC
outlet and to be supplied with power from the DC outlet. The
surrounding wall is adapted to be inserted into an insertion
groove of the DC outlet which is formed around the pin-insertion
holes. The surrounding wall is formed in a substantially
quadrangular shape, viewed from a front side thereof. The plug
pins are arranged along a reference surface corresponding to one
inner surface of the surrounding wall and offset closer to the reference
surface than to an inner surface opposite to the reference
surface.