Field of the Invention
The present invention relates to a switching block and
a switching device including the same.
Conventionally, there is provided a terminal device
attached to a mounting frame for wiring accessories and
embedded in an installation surface (see, e.g., Japanese
Unexamined Patent Application Publication No. 2007-323936;
paragraphs [0020] to [0050] , and Figs. 1 to 4) . The
terminal device, e.g., a switching device having a single-
pole switching mechanism with a single-pole/single-throw
switching contact, includes: a terminal block having a quick
connecting terminal for locking an electric wire inserted
through a wire insertion hole; a body for accommodating a
switching block having movable and fixed contacts; and a
cover for covering an opening in a front surface of the
body.
A pair of mounting claws for attaching the terminal
device to the mounting frame is provided on both ends in a
longitudinal direction of the cover, respectively. Each of
the mounting claws is engaged with a corresponding mounting
hole of the mounting frame, so that the terminal device is
fixed to the mounting frame. Further, a handle {including a
reverse handle and a handle cover) for controlling on/off
operations of the switch is attached to the cover.
In the terminal device disclosed in the Japanese
Unexamined Patent Application Publication No. 2007-323936,
the mounting claws provided in the cover are engaged with
the mounting frame. If the handle extending beyond
positions of the mounting claws is attached to the mounting
frame, the handle contacts with the mounting frame, which
impedes the operations of the handle. In other words, when
the handle has a width dimension larger than that of the
cover in such a direction that the mounting claws are
arranged, the handle can hardly be attached to the mounting
frame. Further, in conventional manners, the width
dimension of the cover is designed to be fitted to a size of
the body. Accordingly, in cases where the handle having a
width dimension larger than that of the body is employed,
the body and the cover are necessary to be replaced to the
larger ones.
Summary of the Invention
In view of the above, an object of the present
invention is to provide a switching block capable of
attaching a handle having a width dimension larger than that
of a body, and a switching device including the same.
In accordance with an aspect of the present invention
there is provided a switching block adapted to be detachably
attached to a mounting frame for wiring accessories, an
operational handle being adapted to be swingably attached on
a front surface side of the mounting frame. The switching
block includes a body having a box-like shape whose front
surface side is opened; a cover attached to the body to
close the opening in the front surface side of the body; and
an inversion part swingably engaged with the cover for
inverting an internal contact provided in the body according
to its rocking operation. The handle is adapted to be
detachably attached to the inversion part. The cover has an
attaching portion for attaching the cover to the mounting
frame and the attaching portion protrudes outwardly beyond
the body.
In the switching block, the cover is preferably
provided with a relief groove for avoiding the handle from
coming into contact with the cover when the handle is
rocked.
In the switching block, a reinforcing rib is preferably
provided on a rear surface side of the attaching portion.
In accordance with another aspect of the present
invention, there is provided a switching device including
the above-described switching block; a mounting frame, for
an embedded wiring accessory, to which the switching block
is detachably attached; and an operational handle swingably
attached to the front surface side of the switching block.
Preferably, the switching device further includes a
bracket for covering an area which is not covered with the
cover in the opening of the mounting frame.
In accordance with the switching block and the
switching device, the handle having a width dimension larger
than that of the body can be attached to the switching
block.
Brief Description of the Drawings
The objects and features of the present invention will
become apparent from the following description of
embodiments, given in conjunction with the accompanying
drawings, in which:
Fig. 1 is an exploded perspective view showing a
switching device in accordance with an embodiment of the
present invention;
Figs. 2A and 2B show the switching device in Fig. 1,
wherein Fig. 2A is a front external view, and Fig. 2B is a
rear external view;
Figs. 3A and 3B show an example of the switching device
in the state where a decorative plate is removed from the
switching device in Fig. 1, wherein Fig. 3A is an external
view, and Fig. 3B is a side cross sectional view;
Figs. 4A and 4B show a modification of the switching
device in the state where the decorative plate is removed
from the switching device in Fig. 1, wherein Fig. 4A is an
external view, and Fig. 4B is a side cross sectional view;
and
Fig. 5A is an external view of a switching block
configuring the switching device in Fig. 1, and Fig. 5B is
an external view of a cover configuring the switching block
when viewed from its rear side.
Detailed Description of the Embodiment
Hereinafter, a switching block and a switching device
in accordance with an embodiment of the present invention
will be described in detail with reference to Figs. 1 to 5B.
The switching device of the present embodiment, for example,
is embedded in an installation surface such as a wall
surface, and used as a change-over switch for switching
on/off lighting equipment mounted on a ceiling surface.
Note that, in the following description, unless otherwise
noted, an up-down direction in Fig. 3B is defined as a
front-rear direction, a right direction in Fig. 3B is
defined as an upward direction, a left direction in Fig. 3B
is defined as a downward direction, and. a direction
perpendicular to the sheet in Fig. 3B is defined as a right-
left direction.
Fig. 1 is an exploded perspective view showing the
switching device A of the present embodiment. The switching
device A includes a switching block 1; a mounting frame 2 to
which the switching block 1 is detachably attached from
behind; a decorative plate 3 attached to a front surface
side of the mounting frame 2; and a handle 4 swingably
attached to a front surface side of the switching block 1.
The mounting frame 2, molded of insulating resin, is
formed into a rectangular frame shape having an opening 21
in its center portion for exposing the front surface
(functional surface) of the switching block 1. On both left
and right sides of the opening 21 in the mounting frame 2,
there are respectively provided elliptical screw-insertion
holes 2 5 through which a mounting screw (not shown) for
fixing the mounting frame 2 to an embedded box (not shown)
embedded in the installation surface is to be inserted.
Further, on each of upper and lower sides of the opening 21
in the mounting frame 2, a pair of locking holes 22 is
provided. Locking holes 2 3 are provided on both right and
left sides of each pair of locking holes 22. Furthermore,
locking holes 2 4 are provided at four corners of the
mounting frame 2, respectively.
The decorative plate 3, molded of insulating resin, is
formed into a rectangular frame shape having an opening 31
in its center portion for exposing the front surface of the
switching block 1 attached to the mounting frame 2.
Further, the decorative plate 3 is designed to cover a front
surface of the mounting frame 2b entirely, i.e., is designed
to have external dimensions slightly larger than those of
the mounting frame 2. Furthermore, on a rear surface of the
decorative plate 3, locking claws 32 {see Fig. 2B) are
provided so as to correspond to the respective locking holes
2 4 of the mounting frame 2. Accordingly, each locking claw
32 of the decorative plate 3 is locked into the
corresponding locking hole 24 of the mounting frame 2,
whereby the decorative plate 3 is fixed to the mounting
frame 2.
The handle 4, molded of insulating resin, is formed
into a rectangular plate shape designed to have
substantially the same dimension as that of the opening 31
in the decorative plate 3. A protrusion 41 for indicating a
press position in the handle 4 is provided on a lower and
center portion of the handle 4. Further, a plurality of
locking claws 42 (see Fig. 3B) is provided on a rear surface
of the handle 4.
As shown in Fig. 1, the switching block 1 includes a
body 11 with a rectangular box shape whose front surface
side is opened; a cover 12 attached to the body 11 so as to
close the opening in the front surface side of the body 11;
and terminal plates 14, 15 and a contact plate 16 which
constitute an internal contact. Further, the switching
block 1 includes a plurality of locking springs 17 (four
pieces in Fig. 1) for locking electric wires (not shown)
inserted through wire insertion holes 11a described below
and electrically connected to the respective terminal plates
14, 15; and an inversion part 13 for inverting the internal
contact according to its rocking operation. Furthermore,
the switching block 1 includes a plurality of release
buttons 18 (two pieces in Fig. 1) for releasing the electric
wire locked by the locking spring 17.
The body 11, molded of insulating resin, includes a
pair of assembly protrusions lie, lie provided on each of
side-walls in the right-left direction of the body 11 so as
to be separated from each other in the up-down direction.
Further, at four corners of the bottom surface (rear
surface) of the body 11, there are provided the wire
insertion holes 11a for inserting the electric wires (not
shown) into the body 11 from an external power source or a
load (see Fig. 2B) . Furthermore, around the wire insertion
holes 11a in the bottom surface of the body 11, there are
provided operation holes lib through which a tip end of a
tool (e.g., flat-blade screwdriver) can be inserted. The
operation holes lib are used for operating the respective
release buttons 18. Herein, an up-down dimension (width
dimension) of the body 11 is designed to be smaller than
that of the opening 21 in the mounting frame 2.
The cover 12, molded of insulating resin, includes a
cover body 12a formed into a rectangular frame shape having
external dimensions substantially the same as those of the
body 11. In upper and lower sides of the cover body 12a,
attaching portions 12b protruding outside beyond the body 11
are provided integrally. Further, in left and right sides
of the opening 12c in the cover body 12a, there are provided
engaging grooves 12d (only one is illustrated in Fig. 1)
with which the inversion part 13 is swingably engaged.
Furthermore, on each of side-walls in the right-left
direction of the cover body 12a, a pair of tongue shaped
assembly pieces 12e is provided to protrude rearward and to
be separated from each other in the up-down direction.
Thus, each of the assembly protrusions lie of the body 11 is
inserted into the assembly hole of the corresponding
assembly tongue piece 12e of the cover 12, so that each
assembly protrusion lie is engaged with the corresponding
assembly tongue piece 12e, whereby the body 11 is coupled to
the cover 12.
Additionally, in each attaching portion 12b of the
cover 12, a pair of locking claws 12g is provided so as to
correspond to the pair of locking holes 22 in the mounting
frame 2, respectively. Each of the locking claws 12g is
engaged with the corresponding locking hole 22, whereby the
switching block 1 is attached to the mounting frame 2.
Further, U-shaped relief grooves 12f are provided between
the cover body 12a and the respective attaching portions
12b. Furthermore, as shown in Fig. 5B, a reinforcing rib
12h is provided on a rear surface of each of the attaching
portions 12b. The reinforcing rib 12h strengthens the
attaching portion 12b.
Herein, the terminal plate 14 is accommodated in one
end side of the body 11 in the up-down direction (upper side
in Fig. 1) . The terminal plate 15 is accommodated in the
other end side of the body 11 in the up-down direction
(lower side in Fig. 1) . The contact plate 16 is swingably
accommodated between these terminal plates 14, 15. Further,
the body 11 accommodates the locking springs 17 (four pieces
in Fig. 1) for clamping the electric wires (not shown) in
combination with the respective terminal plates 14, 15; and
the release buttons 18 for releasing the electric wires
locked by the locking springs 17 and the respective terminal
plates 14, 15.
The terminal plate 14 is formed into a substantially U-
shape by using a conductive material plate (e.g., copper
based metallic material or the like). A fixed contact 14a
is integrally provided on one end side (lower side in Fig.
1) of the terminal plate 14 in the up-down direction.
Further, the terminal plate 15, like the terminal plate 14,
is formed into a substantially U-shape by using a conductive
material plate. A connection piece 15a electrically
connected to the contact plate 16 is integrally provided on
one end side (upper side in Fig. 1) of the terminal plate 15
in the up-down direction. Furthermore, the contact plate
16, like the terminal plates 14 and 15, is formed into a
substantially U-shape by using a conductive material plate.
A movable contact 16a which is separately in contact with
the fixed contact 14a is integrally provided on one end side
(upper side in Fig. 1) of the contact plate 16 in the up-
down direction. When the movable contact 16a of the contact
plate 16 comes into contact with the fixed contact 14a of
the terminal plate 14 in response to the movement of the
inversion part 13, the terminal plate 14 and the terminal
plate 15 are electrically connected to each other via the
contact plate 16 (see Fig. 4B) . Note that an operation of
the switching device A will be described below.
Each of the locking springs 17, like the terminal
plates 14, 15 and the contact plate 16, is made of a
conductive material and accommodated in the body 11 so as to
correspond to each of the wire insertion hole 11a formed in
the body 11. In the present embodiment, two locking springs
17 are disposed so as to correspond to the respective
terminal plates 14, 15 and configures so-called a quick
connection terminal in combination with the terminal plates
14, 15. Therefore, the electric wires are respectively
clamped between the terminal plates 14, 15 and the
corresponding locking springs 17, so that the electric wires
corresponding to the respective terminal plates 14, 15 are
electrically connected to the terminal plates 14, 15.
The release button 18, serving to release the electric
wire mechanically held by the locking spring 17, is molded
of resin and has a rectangular column shape whose axial
direction is directed to the front-rear direction. In the
present embodiment, the release button 18 includes a first
release button 18 accommodated in the body 11 to face two
locking springs 17 corresponding to the terminal plate 14;
and a second release button 18 accommodated in the body 11
to face two locking springs 17 corresponding to the terminal
plate 15. Note that these release buttons 18 are
accommodated in the body 11 so as to correspond to the
operation holes lib, respectively. Further, when the tip
end of the tool is inserted into the body 11 through the
operation hole lib, the corresponding release button 18 is
pressed forwardly and the locking spring 17 is further
pressed forwardly, whereby the electric wire mechanically
held by the locking spring 17 is released, so that the
electric wire can be separated.
The inversion part 13, molded of insulating resin, is
formed into a rectangular box-shape. On both side walls in
the left-right direction of the inversion part 13, there are
respectively provided engaging protrusions 13a swingably
engaged with the engaging grooves 12d of the cover 12 (only
one illustrated in Fig. 1). Further, on both side walls in
the up-down direction of the inversion part 13, there are
respectively provided locking protrusions 13b to which the
handle 4 is attached. Furthermore, in a rear surface of the
inversion part 13, there is provided an insertion recess
portion 13c into which one end of a reverse spring 6 is
inserted (see Fig. 4B) . Note that the other end of the
reverse spring 6 is inserted into a recess of the contact
plate 16 that is disposed so as to correspond to the
insertion recess portion 13c of the inversion part 13 (see
Fig. 4B) . Herein, the engaging groove 12d provided in the
cover 12 is designed to have a width dimension larger than
that of the engaging protrusion 13a provided on the
inversion part 13, whereby the inversion part 13 can be
rocked at a predetermined rocking angle.
Since the opening 21 of the mounting frame 2 has a size
in the left-right direction larger than that of the cover
12, the cover 12 fails to close the opening 21 entirely even
if the switching block 1 is attached to the mounting frame
2. Accordingly, in the state where the handle 4 is removed,
there is a concern that a human body could touch a live part
through the left and right sides of the switching block 1.
Therefore, in the present embodiment, brackets 5 are
provided to cover areas which are not covered with a cover
12 in the opening 21 of the mounting frame 2.
Each of the bracket 5, molded of insulating resin, has
a body part 51 with an elongated plate shape in the up-down
direction. On both sides in the up-down direction of the
body part 51, mounting pieces 52 protruding forward are
integrally provided. Further, on each of the mounting
pieces 52, a locking claw 53 is provided so as to correspond
to the locking hole 23 of the mounting frame 2.
Accordingly, the locking claws 53 are respectively engaged
with the corresponding locking holes 23 of the mounting
frame 2, so that the brackets 5 are attached to the mounting
frame 2.
Hereinafter, an assembly procedure of the switching
block 1 will be described in detail. After accommodating
the terminal plates . 14, 15, the contact plate 16, the
locking springs 17, and the release buttons 18 in the body
11, an operator accommodates the inversion part 13 in the
body 11. Note that, at this time, the other end of the
reverse spring 6, whose one end has already been inserted
into the insertion recess portion 13c, is inserted into the
recess of the contact plate 16. Finally, the operator
engages the assembly protrusions lie of the body 11 with the
respective assembly tongue pieces 12e of the cover 12
corresponding thereto, whereby the body 11 and the cover 12
are coupled to complete the assembly of the switching block
1 (see Fig. 5A) . Note that, at this time, the engaging
protrusions 13a of the inversion part 13 are engaged with
the respective engaging grooves 12d of the cover 12
corresponding thereto, whereby the inversion part 13 is
swingably attached to the cover 12.
Subsequently, an installation process of the switching
device A will be described in detail. The operator engages
the locking claws 12g, provided on the cover 12 of the
switching block 1, with the corresponding locking holes 22
of the mounting frame 2, so that the switching block 1 is
attached to the mounting frame 2. Further, the operator
engages the locking claws 53/ provided on the brackets 5,
with the corresponding locking holes 23 of the mounting
frame 2, so that the brackets 5 are attached to the mounting
frame 2. Note that, in this state, the opening 21 of the
mounting frame 2 is covered with the switching block 1 and
the brackets 5. Accordingly, there is no concern that the
operator could touch the live part from the front surface
side .
Next, the operator fixes the mounting frame 2 to an
embedded box (not shown) by using mounting screws (not
shown) inserted through the respective screw insertion holes
25 of the mounting frame 2. Further, the operator engages
the locking claws 42, provided on the handle 4, with the
corresponding locking protrusions 13b of the inversion part
13, so that the handle 4 is attached to the inversion part
13. Finally, the operator engages the locking claws 32,
provided on the decorative plate 3, with the corresponding
locking holes 24 of the mounting frame 2, whereby the
decorative plate 3 is fixed to the mounting frame 2 to
complete the assembly of the switching device A.
Additionally, an operation of the switching device A
will be described with reference to Fig. 4B. When a user
presses the lower end (left side in Fig. 4B) of the handle 4
rearwardly (lower side in Fig. 4B) , the handle 4 and the
inversion part 13 are rocked counterclockwise, as shown in
Fig. 4B, about a contact portion between the engaging groove
12d and the engaging protrusion 13a engaged with each other.
At this time, the reverse spring 6 is pressed upwardly
(right side in Fig. 4B) by the inversion part 13 to be
convex upward. Accordingly, the contact plate 16 is pressed
upwardly, so that the movable contact 16a of the contact
plate 16 comes into contact with the fixed contact 14a of
the terminal plate 14. Herein, a lower end part of the
contact plate 16 is in contact with the connection piece 15a
of the terminal plate 15, so that the terminal plate 14 and
the terminal plate 15 are electrically connected with each
other via the contact plate 16 (see Fig. 4B) .
From the state illustrated in Fig. 4B, when the user
presses the upper end (right side in Fig. 4B) of the handle
4 rearwardly, the handle 4 and the inversion part 13 are
rocked clockwise about the contact portion in Fig. 4B. At
this time, the reverse spring 6 is pressed downward (left
side in Fig. 4B) by the inversion part 13 to be convex
downward. Accordingly, the contact plate 16 is pressed
downward, so that the movable contact 16a of the contact
plate 16 is separated from the fixed contact 14a of the
terminal plate 14. Consequently, the terminal plate 14 and
the terminal plate 15 are not electrically connected with
each other.
Herein, Figs. 3A and 3B show an example of the
switching device A in the state where the decorative plate 3
is removed, in which the handle 4 is designed to have an up-
down dimension (width dimension) of 42 mm. On the other
hand, Figs. 4A and 4B show another example of the switching
device A in the state where the decorative plate 3 is
removed/ in which the handle 4 is designed to have an up-
down dimension (width dimension) of 52 mm. Further,
although not illustrated, it may be possible to attach a
handle having an up-down dimension (e.g., 36 mm) smaller
than that of the handle shown in Fig. 3 by disposing the
locking claws 4 2 on the same position as in the handles 4
shown in Figs. 3A, 3B and 4A, 4B. In other words, according
to the switching device A of the present embodiment, when
the handle 4 is replaced with a handle having a different
size, it is sufficient to replace only the handle 4 and the
decorative plate 3. This makes it easier to perform the
replacing work, so that replacing cost can be reduced.
Meanwhile, the rocking angle of the handle 4 depends on
the width dimensions of the engaging groove 12d and the
engaging protrusion 13a of the inversion part 13. Since the
rocking angle has a substantially constant value regardless
of the size of the handle 4, the handle 4 may come into
contact with the cover 12 if the handle 4 has an increased
up-down dimension. In the present embodiment, the relief
groove 12f is provided on the cover 12, so the relief groove
12f can receive the end part of the handle 4 even if the
handle 4 has an increased up-down dimension. This avoids
the handle 4 from coming into contact with the cover 12.
Thus, in accordance with the present embodiment, the
attaching portions 12b for attaching the switching block 1
to the mounting frame 2 are provided to extend outwardly
beyond the body 11. This makes it possible to attach the
handle 4 having an up-down dimension (width dimension)
larger than that of the body 11. Additionally, by using the
switching block 1, various kinds of handles 4 with different
sizes can be attached to the switching block 1.
Nevertheless, the body 11 has its original size, so a space
for accommodating an extra wiring is ensured in the embedded
box. Consequently, the wiring can compactly be accommodated
in the embedded box. Further, the reinforcing rib 12h is
provided on the rear surface of each of the attaching
portions 12b to strengthen the attaching portion 12b,
thereby suppressing an occurrence of cracks and deformations
upon operating the handle. This suppresses the switching
block 1 from being detached from the mounting frame 2.
Besides, in accordance with the present embodiment, by
using the above switching block 1, there is provided the
switching device A suitable for various kinds of handles 4
with different sizes. Moreover, even when the handle 4 is
removed, there is no concern that an operator could touch a
live part through the areas which are not covered with the
cover 12 in the opening 21 of the mounting frame 2 by
covering the above areas with the brackets 5 in the present
embodiment.
While' the invention has been shown and described with
respect to the embodiments, it will be understood by those
skilled in the art that various changes and modification may
be made without departing from the scope of the invention as
defined in the following claims.
We claim:
1. A switching block adapted to be detachably attached to
a mounting frame for wiring accessories, an operational
handle being adapted to be swingably attached to a front
surface side of the switching block, comprising:
a body having a box-like shape whose front surface side
is opened;
a cover attached to the body so as to close the opening
in the front surface side of the body, the cover having an
attaching portion for attaching the cover to the mounting
frame, the attaching portion protruding outwardly beyond the
body; and
an inversion part swingably engaged with the cover for
inverting an internal contact provided in the body according
to a rocking operation thereof, the handle being adapted to
be detachably attached to the inversion part.
2. The switching block as set forth in Claim 1, wherein
the cover is provided with a relief groove for avoiding
the handle from coming into contact with the cover when the
handle is rocked.
3. The switching block as set forth in Claim 1 or 2,
wherein a reinforcing rib is provided on a rear surface of
the attaching portion.
4. A switching device, comprising:
the switching block as set forth in any one of Claims 1
to 3;
a mounting frame, for an embedded wiring accessory, to
which the switching block is detachably attached; and
an operational handle swingably attached to the front
surface side of the switching block.
5. The switching device as set forth in Claim 4, further
comprising:
a bracket covering an area which is not covered with
the cover in the opening of the mounting frame.

ABSTRACT

A switching block 1, which is detachably attached to a
mounting frame for wiring accessories, includes a body 11
having a box-like shape whose front surface side is opened;
and a cover 12 attached to the body 11 so as to close the
opening in the front surface side of the body. On a front
surface of the cover 12, there is provided an inversion part
13 for inverting an internal contact. A handle 4 is
detachably attached to the inversion part 13. Further, the
cover 12 has attaching portions 12b for attaching the cover
12 to the mounting frame 2. The attaching portions 12b
protrude outwardly beyond the body 11. According to the
switching block 1, the handle 4 having a width dimension
larger than that of the body 11 can be attached to the
switching block 1.