Title: Electronic keyboard musical instrument
Abstract: Casing of an electronic keyboard musical instrument includes two discrete parts: a main casing section; and a rear casing section. The main casing section includes a bottom plate having a keyboard section placed thereon, a keyslip portion extending upward from the bottom plate in front of the keyboard section, and left and right side plates extending upward from the bottom plate at left and right sides of the keyboard section. The rear casing section includes a roof plate forming a rear upper surface of the casing, and a back plate extending downward from a rear edge of the roof plate. The rear casing section is detachably attached to the main casing section by means of a slidingly-attaching structure for slidingly attaching the rear casing section to the left and right side plates of the main casing section.
Patent Number: 6,972,358 Issued on 12/06/2005 to Ishihara, et al.
| Inventors:
|
Ishihara; Hideki (Hamamatsu, JP);
Mori; Naohisa (Hamakita, JP)
|
| Assignee:
|
Yamaha Corporation (Hamamatsu, JP)
|
| Appl. No.:
|
016307 |
| Filed:
|
December 17, 2004 |
Foreign Application Priority Data
| Sep 19, 2001[JP] | 2001-285072 |
| Current U.S. Class: |
84/177; 84/176; 84/186.1; 84/174; 84/184; 84/185 |
| Intern'l Class: |
G10C 003/02 |
| Field of Search: |
84/177,174,176,186.1,184,185,175
|
References Cited [Referenced By]
U.S. Patent Documents
| 3338127 | Aug., 1967 | Engelbert.
| |
| 5465644 | Nov., 1995 | Shimoda et al.
| |
| 5550926 | Aug., 1996 | Tsao.
| |
| 5789693 | Aug., 1998 | Lawson.
| |
| 6180859 | Jan., 2001 | Konishi.
| |
| Foreign Patent Documents |
| 352026821 | Feb., 1977 | JP.
| |
| 53-84331 | Jul., 1978 | JP.
| |
| 54-25819 | Feb., 1979 | JP.
| |
| 62-103382 | Jul., 1987 | JP.
| |
| 5-75797 | Oct., 1993 | JP.
| |
| 05-76190 | Oct., 1993 | JP.
| |
| 05-307390 | Nov., 1993 | JP.
| |
| 5-96888 | Dec., 1993 | JP.
| |
| 06-027956 | Feb., 1994 | JP.
| |
| 6-21096 | Mar., 1994 | JP.
| |
| 6-26386 | Apr., 1994 | JP.
| |
| 2516897 | Aug., 1996 | JP.
| |
| 10-207461 | Aug., 1998 | JP.
| |
Primary Examiner: Hsieh; Shih-Yung
Attorney, Agent or Firm: Morrison & Foerster LLP
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATION
This application is a divisional application of application Ser. No. 10/722,328
filed on Nov. 24, 2003, which is a continuation of application Ser. No. 10/243,881,
filed on Sep. 13, 2002 (now abandoned), both of which are specifically incorporated
herein, in their entirety, by reference.
Claims
1. An electronic keyboard musical instrument comprising a keyboard section and
a casing that accommodates therein said keyboard section, said casing comprising:
a main casing section; and
a rear casing section including at least a roof plate forming an upper surface
of said casing, and a back plate extending downward from a rear edge of said roof plate,
wherein said rear casing section is detachably attachable to said main casing
section to constitute said casing,
wherein said back plate has a main tone hole formed therein, and a speaker is
disposed with a front thereof opposed to said main tone hole, and
wherein said roof plate has subsidiary tone hole formed therein to allow a sound
outputted via said speaker to escape therethrough.
2. An electronic keyboard musical instrument as claimed in claim 1, wherein acoustical
vibrations from the backside of the speakers are emitted from the subsidiary tone hole.
3. An electronic keyboard musical instrument comprising a keyboard section and
a casing that accommodates therein said keyboard section,
wherein said casing includes a bottom plate portion having said keyboard section
placed thereon, a keyslip portion extending upward from said bottom plate portion
in front of said keyboard section, a roof plate portion forming an upper surface
of said casing, a back plate portion extending downward from a rear edge of said
roof plate portion, and side plate portions connecting said roof plate portion
and said bottom plate portion at left and right sides of said keyboard section,
wherein said casing is separable into a main casing section that includes said
bottom plate portion and keyslip portion and a rear casing section that includes
at least said back plate portion, so that said rear casing section is detachably
attached to said main casing section, and
wherein said rear casing section further includes a reinforcing plate coupling
said roof plate portion and said back plate portion, and said main casing section
and said rear casing section are coupled with each other by securing said reinforcing
plate and said bottom plate portion with a fastener, with said bottom plate portion
held between a lower end portion of said reinforcing plate and a lower edge portion
of said back plate portion.
4. An electronic keyboard musical instrument as claimed in claim 3 where said
fastener is a screw.
5. An electronic keyboard musical instrument as claimed in claim 3 where said
fastener is a resiliently-deformable fitting member.
6. An electronic keyboard musical instrument comprising a keyboard section and
a casing that accommodates therein said keyboard section, said casing comprising:
a main casing section including a bottom plate having said keyboard section placed
thereon, and a keyslip portion extending upward from said bottom plate in front
of said keyboard section; and
a rear casing section including a roof plate forming a rear upper surface of
said casing, and a back plate extending downward from a rear edge of said roof plate,
wherein a circuit board of an operation panel and a main circuit board of said
electronic keyboard musical instrument are provided on said rear casing section,
wherein said rear casing section is detachably attached to said main casing section
along with individual ones of said circuit boards.
7. An electronic keyboard musical instrument comprising a keyboard section and
a casing that accommodates therein said keyboard section, said casing comprising:
a main casing section including at least a bottom plate having said keyboard
section placed thereon, and a keyslip portion extending upward from said bottom
plate in front of said keyboard section;
a rear casing section including at least a roof plate forming an upper surface
of said casing, and a back plate extending downward from a rear edge of said roof
plate; and
a connecting assembly for slidingly attaching said rear casing section to said
main casing section, whereby said rear casing section is detachably attached to
said main casing section to constitute said casing.
8. An electronic keyboard musical instrument as claimed in claim 7 wherein said
connecting assembly slidingly attaches said rear casing section to said side plates
of said main casing section.
9. An electronic keyboard musical instrument as claimed in claim 7 wherein said
connecting assembly includes a slidingly-pressing structure that, when said rear
casing section is slide, in a back-to-front direction, relative to said main casing
section for detachable attachment to said main casing section, applies greater
pressing force as an amount of sliding movement of said rear casing section relative
to said main casing section increases.
Description
BACKGROUND OF THE INVENTION
The present invention relates generally to electronic keyboard musical instruments,
and more particularly to an improvement in casing structures of the electronic
keyboard musical instruments.
In electronic keyboard musical instruments having a generally flat casing, the
casing structure includes a bottom plate having a keyboard section placed thereon,
a keyslip portion disposed right in front of the keyboard section, a pair of left
and right side plates located close to the left and right sides of the keyboard
section, and a roof plate forming a rear upper surface of the casing, and a bottom
plate. However, when maintenance and inspection operations are to be performed
on the interior of the casing, it is very troublesome to disassemble and then re-assemble
the thus-constructed casing structure.
Japanese Utility Model Laid-open Publication No. SHO-62-103382 discloses
an electronic keyboard musical instrument having an improved casing. The improved
casing is composed of a main casing section and a rear casing section integrally
forming a rear upper surface of the casing. The rear casing section is hinged to
a bottom plate of the main casing section so that the rear casing section can be
pivotally moved between open and closed positions. However, in assemblage of the
casing, last screwing for fastening the rear casing section to the main casing
section is performed, without exception, on the upper surface of the casing, so
that the screw heads are inevitably exposed on the upper surface of the casing,
presenting undesirable external appearance. Further, because the rear casing section
is not detachably attachable to the main casing section in the disclosed casing,
the assembling operations tend to be very troublesome, and maintenance and inspection
of circuit boards etc. within the casing are also difficult to perform.
Further, in the electronic keyboard musical instruments of the above-mentioned
types, the main circuit board is mounted on the bottom plate, for ease of the maintenance
and inspection. However, where the main circuit board is to be mounted on the bottom
plate near the back of the keyboard section, the bottom place must have an increased
horizontal dimension in a front-and-back direction of the casing, which would therefore
increase the overall horizontal dimension, in the front-and-back direction, of
the keyboard musical instrument. Further, where the main circuit board is to be
mounted on the bottom plate under the keyboard section, the overall vertical dimension
or thickness of the keyboard musical instrument would increase.
SUMMARY OF THE INVENTION
In view of the foregoing, it is an object of the present invention to provide
an electronic keyboard musical instrument having an improved casing structure which
allows a instrument's casing to be assembled with increased ease and in such a
manner as to achieve good external appearance, and which can facilitate maintenance
and inspection of the interior of the casing.
In order to accomplish the above-mentioned object, the present invention provides
an electronic keyboard musical instrument comprising a keyboard section and a casing
that accommodates therein the keyboard section. In the present invention, the casing
comprises: a main casing section including a bottom plate having the keyboard section
placed thereon, a keyslip portion extending upward from the bottom plate in front
of the keyboard section, and left and right side plates extending upward from the
bottom plate at left and right sides of the keyboard section; a rear casing section
including a roof plate forming a rear upper surface of the casing, and a back plate
extending downward from a rear edge of the roof plate; and a slidingly-attaching
structure that slidingly attaches the rear casing section to the main casing section.
Thus, the rear casing section is detachably attachable to the main casing section
to constitute the casing. Because, in the present invention, the rear casing section
and main casing section, constituting the casing, are discrete or separate parts
and the rear casing section is detachably attached to the main casing section by
means of the slidingly-attaching structure, the casing can be assembled and/or
disassembled with ease and in such a manner as to achieve good external appearance,
and there can be provided an improved casing structure which facilitates maintenance
and inspection of the interior of the casing.
The present invention also provides an electronic keyboard musical instrument
comprising a keyboard section and a casing that accommodates therein the keyboard
section, where the casing comprises: a main casing section including a bottom plate
having the keyboard section placed thereon, and a keyslip portion extending upward
from the bottom plate in front of the keyboard section; a rear casing section including
a roof plate forming a rear upper surface of the casing, and a back plate extending
downward from a rear edge of the roof plate; and left and right side plates extending
upward from the bottom plate at left and right sides of the keyboard section, the
left and right side plates belonging to and being formed integrally with either
one of the main casing section and the rear casing section. In this invention,
a circuit board of an operation panel and a main circuit board of the electronic
keyboard musical instrument are provided on the rear casing section, so that the
rear casing section is detachably attached to the main casing section along with
the individual circuit boards. Because, in the present invention, the rear casing
section and main casing section, constituting the casing, are discrete or separate
parts and the rear casing section, having the individual circuit boards provided
thereon, is detachably attachable to the main casing section, the casing can be
assembled and/or disassembled with ease, and maintenance and inspection of the
interior of the casing can be performed with utmost ease.
The present invention also provides an electronic keyboard musical instrument
comprising a keyboard section and a casing that accommodates therein the keyboard
section, where the casing comprises: a bottom plate having said keyboard section
placed thereon; a keyslip portion extending upward from said bottom plate in front
of said keyboard section; left and right side plates extending upward from said
bottom plate at left and right sides of said keyboard section; a roof plate forming
an upper surface of said casing; and a back plate extending downward from a rear
edge of said roof plate, wherein said casing can be disassembled into said main
casing section, including said bottom plate and said keyslip portion, and said
rear casing section including at least said back plate, and wherein a circuit board
of an operation panel and a main circuit board of said electronic keyboard musical
instrument are provided on said rear casing section, whereby said rear casing section
is detachably attached to said main casing section along with individual ones of
said circuit boards.
While the embodiments to be described herein represent the preferred form of
the present invention, it is to be understood that various modifications will occur
to those skilled in the art without departing from the spirit of the invention.
The scope of the present invention is therefore to be determined solely by the
appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
For better understanding of the object and other features of the present invention,
its preferred embodiments will be described hereinbelow in greater detail with
reference to the accompanying drawings, in which:
FIGS. 1A, 1B and 1C are top plan, rear and bottom views, respectively,
of an electronic keyboard musical instrument in accordance with an embodiment of
the present invention;
FIG. 2 is an exploded view of a casing of the electronic keyboard musical instrument
where a main casing section and a rear casing section are constructed as discrete
or separate parts;
FIG. 3A is a front elevational view of the rear casing section of the electronic
keyboard musical instrument, FIG. 3B is a bottom view of the rear casing section,
and FIG. 3C is a side view of the rear casing section;
FIG. 4 is a top plan view of the main casing section of the electronic keyboard
musical instrument;
FIG. 5A is a plan view explanatory of a slidingly-attaching structure of the
casing in the electronic keyboard musical instrument, and FIG. 5B is a sectional
view taken along the G—G line of FIG. 5A;
FIG. 6A is a schematic perspective view showing another embodiment of a lower
attaching mechanism for attaching the rear casing section to the main casing section,
FIG. 6B is a schematic perspective view showing an example of a snap-fitting engaging
unit, and FIG. 6C is a sectional view schematically showing a state where an engaging
protrusion is fitted in an engaging hole portion; and
FIG. 7A is a schematic exploded perspective view showing another embodiment
of the slidingly-attaching structure for slidingly attaching the rear casing section
to the main casing section, and FIG. 7B is a side view of a slidingly-attaching
projection provided on the rear casing section.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1A is a top plan view showing an electronic keyboard musical instrument
in accordance with an embodiment of the present invention, FIG. 1B is a rear view
of the electronic keyboard musical instrument, and FIG. 1C is a bottom view of
the electronic keyboard musical instrument. The electronic keyboard musical instrument
includes a casing
1, which generally comprises a main casing section
2
and a rear casing section
3 constructed as discrete parts. As schematically
shown in FIG. 2, the rear casing section
3 is removably attached to the
main casing section
2. The main casing section
2 has a bottom plate
5 having a keyboard section
9 placed thereon, a keyslip portion
8
extending upward from the bottom plate
5 right in front of the keyboard
section
9, and a pair of right and left side plates
6a,
6b
extending upward from the bottom plate
5 at left and right sides of
the keyboard section
9. These bottom plate
5, side plates
6a,
6b and keyslip portion
8 are secured to one another by suitable
fastening means, such as screws. The rear casing section
3 has a top or
roof plate
4 that forms a rear upper surface of the casing
1, and
a back plate
7 extending downward from a rear edge of the roof plate
4.
The roof plate
4 and back plate
7 are secured to each other by suitable
fastening means, such as screws. As illustrated in FIG. 1B, the back plate
7
of the rear casing section
3 has two main tone holes
10a and
10b, formed in predetermined positions thereof, for emitting sounds
from left and right speakers (not shown). Further, as seen in FIG. 1A, the roof
plate
4 has subsidiary tone holes
11a and
11b,
formed in predetermined portions thereof, for emitting acoustical vibrations from
the backside of the speakers. On the roof plate
4, there is also provided
an operation panel
12 including various operating switches, displays, etc.
The rear casing section
3 is attached to the main casing section
2
via a slidingly-attaching structure, which slidingly fastens the rear casing section
3 to the right and left side plates
6a and
6b of
the main casing section
2. In the instant embodiment, the slidingly-attaching
structure comprises a set of elements provided on the lower surface of the roof
plate
4 in the rear casing section
3, and a set of elements provided
on the upper ends of the right and left side plates
6a and
6b
in the main casing section
2.
This and following paragraphs describe exemplary details of the rear casing
section
3, with reference to FIGS. 3A to 3C. FIG. 3A is a front elevational
view of the rear casing section
3, which particularly depicts the inner
surface of the back plate
7 as seen from the interior of the casing
1.
FIG. 3B is a bottom view of the rear casing section
3, which particularly
depicts the underside of the roof plate
4 as viewed in a direction of arrow
"a" of FIG. 3A, and FIG. 3C is a right side view of the rear casing section
3,
which particularly depicts a side surface of the rear casing section
3 as
viewed in a direction of arrow "b" of FIG. 3A. As seen from FIG. 3C, the roof plate
4 and back plate
7 constituting the rear casing section
3
are coupled at right angles with each other, and the coupling between the roof
plate
4 and the back plate
7 is reinforced by right and left and
middle vertical securing plates
21a to
21c. In FIG.
3C, the right vertical securing plate
21a has a rear end connected
to the back plate
7 and an upper end connected to the roof plate
4,
and the right securing plate
21a also has a lower end portion
53a
bent horizontally outward from its vertical portion. As will be later described,
the horizontally-bent lower end portion
53a of the right securing
plate
21a can be secured to the bottom plate
5 by means of
a screw or the like. The other vertical securing plates
21b and
21c
are constructed in a similar manner to the right securing plate
21a.
As seen in FIG. 3A, speakers
20a and
20b are provided
on predetermined positions of the back plate
7 near left and right ends
of the back plate
7. The middle securing plate
21c also functions
as an acoustic separator between the speakers
20a and
20b.
Further, the back plate
7 has a lower end edge
51 bent horizontally
inward, which is secured to and along one edge of the bottom plate
5 by
means of screws or the like.
As further shown in FIG. 3B, the roof plate
4 has projections
31a
to
31d formed at predetermined positions of its underside near
right and left ends thereof so that the projections
31a to
31d
can function as elements of the slidingly-attaching structure for slidingly
attaching the rear casing section
3 to the right and left side plates
6a
and
6b. As seen in FIGS. 3B and 3C, the slidingly-attaching projections
31a and
31b are provided on a predetermined right end
portion of the underside or inner surface of the roof plate
4 and located
adjacent to front and rear edges, respectively, of the roof plate
4. These
right slidingly-attaching projections
31a and
31b each
have a screw head
33a or
33b formed at its distal end
and a proximal-end flange
34a or
34b spaced from the
screw head
33a or
33b by a predetermined distance;
thus, a gap portion
32a,
32b is formed between the
screw head
33a,
33b and the flange
34a,
34b. The slidingly-attaching projections
31c and
31d,
provided on a predetermined left end portion of the underside or inner surface
of the roof plate
4, are constructed similarly to the right slidingly-attaching
projections
31a and
31b.
This and following paragraphs describe examples of elements of the slidingly-attaching
structure provided on the right and left side plates
6a and
6b
of the main casing section
2, with reference to FIGS. 4 and 5. Specifically,
FIG. 4 is a top plan view of the main casing section
2, and FIG. 5A is an
enlarged top plan view of the right side plate
6a. Slide portions
35a to
35d are provided on rear upper surfaces of the
right and left side plates
6a and
6b of the main casing
section
2, at positions corresponding to the slidingly-attaching projections
31a to
31d of the rear casing section
3. As
illustrated in FIG. 5A, each of the slide portions
35a,
35b
of the right side plate
6a has a large opening
36a,
36b, an elongated opening
37a,
37b communicating
with the large opening
36a,
36b and extending from
the large opening
36a,
36b in a forward direction of
the casing
1, and a recessed portion
38a,
38b surrounding
the corresponding large opening
36a,
36b and elongated
opening
37a,
37b. Each of the large opening
36a,
36b has such a diameter as to allow passage therethrough of the screw
head
33a,
33b of the corresponding slidingly-attaching
projection
31a,
31b. Each of the elongated opening
37a,
37b has a width smaller than the diameter of each
of the screw head
33a,
33b and flange
34a,
34b of the corresponding slidingly-attaching projection
31a,
31b. When the rear casing section
3 and main casing section
2 are joined, the flanges
34a,
34b of the slidingly-attaching
projections
31a,
31b are fitted in the recessed portions
38a,
38b, respectively; namely, the recessed portions
38a,
38b each have a width and depth corresponding
to the dimensions of the flange
34a,
34b. The reverse
side of each of the recessed portions
38a,
38b is tapered
to provide a slanted or tapered surface
39a of FIG. 5B. Slide portions
35c and
35d of the left side plate
6b are
constructed in the same manner as the above-described slide portions
35a
and
35b of the right side plate
6a.
To attach the rear casing section
3 to the main casing section
2,
the rear casing section
3 is first placed in a predetermined position from
behind the main casing section
2 as shown in FIG. 2, and the screw heads
33a,
33b of the slidingly-attaching projections
31a
to
31d are inserted into the corresponding large openings
36a,
36b of the slide portions
35a to
35d formed
on the right and left side plates
6a and
6b. Then,
the entire rear casing section
3 is caused to slide in the forward direction
as indicated by arrow "X". FIG. 5B is a sectional view taken along the G—G
line of FIG. 5A, which shows the slide portion
35a having the corresponding
projection
31a inserted therein. In this state, the flanges
34a,
34b of the individual projections
31a to
31d
are positioned in the corresponding recessed portions
38a,
38b
of the slide portions
35a to
35d, the gap portions
32a,
32b of the individual projections
31a
to
31d are positioned at the same height as the corresponding
large openings
36a,
36b of the slide portions
35a
to
35d, and the screw heads
33a,
33b
of the projections
31a to
31d project downwardly
beyond the corresponding large openings
36a,
36b. Then,
as the rear casing section
3 (roof plate
4 in FIG. 5B) is caused
to slide in the forward direction, i.e. in the arrow "X" direction, the gap portions
32a,
32b of the individual projections
31a
to
31d are guided forward along the corresponding elongated openings
37a,
37b, so that the entire rear casing section
3
can slide forward until it is ultimately attached to the main casing section
2.
In each of the slide portions
35a to
35d, the reverse
side of the recessed portion
38a,
38b is tapered to
provide the slanted or tapered surface
39a extending over a predetermined
range. The tapered surface
39a slopes downwardly toward the front
of the keyboard musical instrument, so that the thickness of the slide portion
progressively increases in a direction toward the front of the keyboard musical
instrument. Thus, in the region where the tapered surface
39a is
formed, the thickness of each of the slide portions
35a to
35d
progressively becomes greater than the vertical width or depth of the corresponding
gap portion
32a or
32b. As a consequence, after the
rear casing section
3 is completely slid to the predetermined mounting position
on the main casing section
2, the slide portions
35a to
35d
are firmly held in the corresponding gap portions
32a,
32b,
i.e. between the screw heads
33a,
33b and the flanges
34a,
34b. Namely, the screw heads
33a,
33b engaging with the slanted surfaces
39a are pressed
downward by the thickness of the corresponding slide portions
35a to
35d, and thus the roof plate
4 of the rear casing section
3 is firmly pressed against the side plates
6a and
6b
and thereby fixed in place. In the above-mentioned manner, the rear casing
section
3 can be properly attached to the main casing section
2 by
being slid forward into locking engagement by the side plates
6a and
6b.
As also illustrated in FIG. 5B, each of the slide portions
35a to
35d has an adjusting protrusion
40a at a rear end of
its underside. The adjusting protrusion
40a is provided right behind
the large opening
36,
36b of each of the slide portions
35a
to
35d. As the rear casing section
3 is slide rearward
for detachment or removal from the main casing section
2, the screw heads
33a,
33b of the slidingly-attaching projections
31a
to
31d are stopped from sliding rearward, by engaging with the
corresponding adjusting protrusions
40a. By the provision of such
adjusting protrusions
40a, the screw heads
33a,
33b
of the slidingly-attaching projections
31a to
31d can
be positioned immediately below the corresponding large openings
36a,
36b, which facilitates smooth operations for detaching the rear casing
section
3 from the main casing section
2.
The main casing section
2 and rear casing section
3, interconnected
via the above-described slidingly-attaching structure, are also connected with
each other between the bottom plate
5 of the main casing section
2
and the rear lower end of the rear casing section
3, in order to reinforce
and make more reliable the coupling between the main casing section
2 and
rear casing section
3.
As illustrated in FIG. 3C, the lower end edge
51 of the back plate
7
is bent inward in a substantial horizontal direction, and a plurality of screw
holes
52 to
52f are formed in the bent portion of the lower
end edge
51. As seen from FIG. 3A, the lower end portions
53a
to
53c of the securing plates
21a to
21c
are also bent substantially horizontally, and a plurality of screw holes
54a
to
54c is formed in each of the lower end portions
53a
to
53c. The horizontally-bent portion of the lower end edge
51
of the back plate
7 is generally at the same height as the lower surface
of the bottom plate
5 while the lower end portions
53a to
53c of the securing plates
21a to
21c are
generally at the same height as the upper surface of the bottom plate
5,
so that the bottom plate
5 can be held between the lower end edge
51
of the back plate
7 and the lower end portions
53a to
53c
of the securing plates
21a. When the rear casing section
3
is to be attached to the main casing section
2, a rear edge portion of the
bottom plate
5 is fitted between the lower end edge
51 of the back
plate
7 and the lower end portions
53a to
53c.
Specifically, the lower end edge
51 of the back plate
7 is brought
into contact with the lower surface of the bottom plate
5 and screwed to
the bottom plate
5 through screws driven in the screw holes
52a
to
52f. Further, the lower end portions
53a to
53c of the securing plates
21a to
21c are
brought into contact with the upper surface of the bottom plate
5 and screwed
to bottom plate
5 through screws driven in the screw holes
54a
to
54c. Such screwing operations are all performed from below
the bottom plate
5 as seen in FIG. 1C. Because the lower end edge
51
of the back plate
7 and the lower end portions
53a to
53c
of the securing plates
21a to
21c are screwed together
at a plurality of positions, and because the respective screwed positions of the
lower end edge
51 and the lower end portions
53a to
53c
are deviated from each other in the front-and-back direction of the keyboard
musical instrument, the rear casing section
3 attached to the main casing
section
2 can be effectively prevented from rattling in the front-and-back direction.
To detach the rear casing section
3 from the main casing section
2,
the screws are removed from the underside of the bottom plate
5, and the
rear casing section
3 is slid in the rearward direction of the keyboard
musical instrument (i.e., in a direction opposite to arrow X). Thus, the fastening
engagement between the projections
31a to
31d of the
rear casing section
3 and the tapered surfaces
39a of the
slide portions
35a to
35d can be released. During the
sliding movement, the screw heads
33a,
33b of the slidingly-attaching
projections
31a to
31d are stopped by the adjusting
protrusions
40a of the slide portions
35a to
35d
so that they are positioned immediately below the corresponding large openings
36a,
36b and thus movable upward through the large
openings
36a,
36b. Then, in the position where the
screw heads
33a,
33b of the slidingly-attaching projections
31a to
31d have been stopped by the adjusting protrusions
40a, it is possible to readily detach the rear casing section
3
from the main casing section
2 by just lifting the rear casing section
3.
Referring back to FIGS. 3A and 3B, main circuit boards
22a and
22b including tone sources etc., are mounted on the back plate
7,
and a circuit board
60 of the operation panel
12 is mounted on a
portion of the underside of the roof plate
4 below the operation panel
12.
Because these circuit boards are mounted on the rear casing section
3, they
can be attached and detached to the and from the main casing section
2 together
with the rear casing section
3. When maintenance operations are to be performed
on the circuit boards within the casing
1, it is only necessary that the
rear casing section
3 be detached from the main casing section
2
by being slid rearward and then be placed in an appropriate position for the intended
operations. Therefore, the maintenance and inspection operations can be performed
with ease. Further, because there is no need to provide a particular space on the
bottom plate
5 for mounting the main circuit boards
22a,
22b
etc., it is possible to reduce the dimension, in the front-and-back direction,
of the bottom plate
5, and hence reduce the overall size and weight of the
keyboard musical instrument.
The embodiment has been described in relation to the case where the right and
left side plates
6a and
6b belong to and are provided
integrally with the main casing section
2; conversely, the right and left
side plates
6a and
6b may belong to and be provided
integrally with the rear casing section
3. In such a modification too, the
basic technical concept of the present invention that the rear casing section
3
is detachably attachable to the main casing section
2 from behind the casing
section
2 can be reflected appropriately. In this case, although the roof
plate
4 and side plates
6a and
6b are of course
secured together by means of L-shape mounting hardware applied to the inner surfaces
of these plates, the front surfaces of the right and left side plates
6a
and
6b and the right and left ends of the keyslip portion
8
are merely held in butting engagement with each other, rather than in fitting engagement
with each other. Namely, the side plates
6a and
6b and
keyslip portion
8 may be constructed such that as the side plates
6a
and
6b are slid forward, the inner edge of the front of the side
plates
6a and
6b are brought into overlap and soft
contact with the opposite end surfaces of the keyslip portion
8. Preferably,
the keyslip portion
8 and the bottom plate
4 are joined with each
other by means of connecting hardware that is a smaller and simplified version
of the above-mentioned the securing plates
21a to
21c or
L-shape connecting hardware.
Further, in the above-described embodiment, the rear lower end of the rear
casing section
3 and the main casing section
2 are secured to each
other by screwing. In a modified embodiment, the rear lower end of the rear casing
section
3 and the main casing section
2 may be secured to each other
by means of a resiliently-deformable fitting members (snap-fitting members). FIG.
6A is a schematic perspective view showing parts of the bottom plate
5
and back plate
7 from below these plates
5 and
7; for convenience,
there are only shown respective left end portions of the bottom and back plates
5 and
7. In the illustrated example, the lower end edge
51
of the back plate
7 has a recess or notch
51a formed in its
base
51b and an upward fitting projection (upward bent portion)
61
formed on the base
51b in adjoining relation to the recess
51a,
and the upward fitting projection
61 has an engaging hole portion
64.
Resiliently-deformable fitting engagement unit
62 is provided on a portion
of the underside of the bottom plate
5 which corresponds in position to
the upward fitting projection
61. FIG. 6B is an enlarged perspective view
of the fitting engagement unit
62, which shows the fitting engagement unit
62 from above to facilitate understanding. The fitting engagement unit
62
has a recess
65 to permit entry therein of the upward fitting projection
61, and a resilient fitting member
63. The resilient fitting member
63 also has an engaging protrusion
63a located immediately
inward of the operating portion
63b and facing the recess
65.
The engaging protrusion
63a has a distal end portion having a tapered
sectional shape with only one side surface (upper surface) slanted downward with
respect to the other side surface (lower surface), and the resilient fitting member
63 is resiliently deformable so that the engaging protrusion
63a
is movable in and out of the recess
65.
To join the back and bottom plates
7 and
5, the fitting projection
61 formed on the lower end edge
51 of the back plate
7 is
inserted in the recess
65 of the fitting engagement unit
62 provided
on the bottom plate
5, so that the tapered end portion of the engaging protrusion
63a is first pressed by the fitting projection
61 until the
protrusion
63a is moved out of the recess
65. Then, as the
insertion of the fitting projection
61 progresses, the pressing force applied
by the projection
61 to the protrusion
63a is released at
the position of the engaging hole portion
64, upon which the engaging protrusion
63a is pushed back into the recess
65 by the resilient force
of the resilient fitting member
63 and thus the engaging protrusion
63a
is brought into fitting engagement with the engaging hole portion
64.
FIG. 6C is a sectional view showing a state where the protrusion
63a
is fitted in the engaging hole portion
64 in the manner as stated above.
By the fitting engagement, the back and bottom plates
7 and
5 are
joined or secured with respect to each other. During the time that the fitting
projection
61 is fitted in the recess
65, the recess
51a
in the lower end edge
51 of the back plate
7 allows the base
51b to have some resiliency such that the back plate
7 can
have considerable flexibility with respect to the bottom plate
5 and thus
can be smoothly fitted in the bottom plate
5.
Further, the resilient fitting member
63 has the upper-end operating
portion
63b extending at a substantially right angle to the engaging
protrusion
63a, and this operating portion
63b is operable
to compulsorily release the fitting engagement between the engaging protrusion
63a and the engaging hole portion
64. To disjoin the back
plate
7 and bottom plate
5 from each other, the operating portion
63b is pulled to move the engaging protrusion
63a out
of the recess
65, so as to release the fitting engagement between the engaging
protrusion
63a and the engaging hole portion
64. Then, the
fitting projection
61 is removed from the recess
65.
The use of the two resiliently-deformable fitting means (i.e., the resilient
fitting member
63 and base
51b) can completely eliminate the
need for screwing to join the main casing section
2 and rear casing section
3, so that the operations for joining and disjoining the main casing section
2 and rear casing section
3 can be performed with increased ease.
Note that the slidingly-attaching structure in the present invention need not
necessarily be of the above-described type and may be constructed in any other
desired manner as long as it allows the rear casing section
3 to be slid
along and then ultimately attached to the main casing section
2. Further,
whereas the embodiments have been described in relation to the case where the lower
surface of the roof plate
4 and the upper surfaces of the side plates
6a,
6b are brought into engagement with each other and slid relative
to each other in the front-and-back direction, the construction of the present
invention is not so limited. For example, the present invention may be constructed
so that the inner surface
75 of the back plate
7 and the rear end
surfaces of the side plates
6a,
6b are brought into
engagement with each other and slid relative to each other in the vertical direction.
Further, whereas the embodiments have been described in relation to the
case where the back plate
7 of the rear casing section
3 and the
roof plate
4 are joined at substantially right angles, the back plate
7
and the roof plate
4 may be joined at any other appropriate angle, such
as 60 or 120 degrees.
Furthermore, where only the arrangement of mounting the main circuit
boards etc. on the rear casing section
3 is employed, other appropriate
means than the above-described slidingly-attaching structure may be used to detachably
join the rear casing section
3 and main casing section
2.
This and following paragraphs describe another embodiment of the slidingly-attaching
structure for slidingly attaching the rear casing section
3 to the main
casing section
2, with reference to FIGS. 7A and 7B. In this embodiment,
slide portions
351a to
351d are provided on the bottom
plate of the main casing section
2, and slidingly-attaching projections
311a to
311d, slidingly engageable with the slide portions
351a to
351d are formed on lower end edges of left
and right legs
41a and
41b extending downward from
the underside of the roof plate
4 of the rear casing section
3. As
seen from, for example, FIG. 7A, a slide member
351 having two slide portions
351c and
351d formed thereon is mounted on one end
(adjacent to one of the side plates
6b) of the bottom plate
5
by screwing or otherwise. Similarly, another slide member, not visible in FIG.
7A, has two slide portions
351a and
351b provided thereon
is mounted on the other end (adjacent to the other side plate
6a)
of the bottom plate
5 by screwing or otherwise. Each of the slide portions
351a to
351d has elements similar to those of the above-described
slide portion
35a of FIGS. 5A and 5B, such as a large opening (
36a),
elongated opening (
37a) and tapered surface (
39a).
Here, detailed illustration and description of these elements are omitted, because
it is believed that FIG. 5 and the corresponding description having been given
above can also be applied here appropriately.
The lower ends of the legs
41a and
41b, extending
downward from the underside of the roof plate
4, are each bent inward at
a substantially right angle to thereby form an elongated horizontal portion. The
slidingly-attaching projections
311a to
311d are provided
on and extend downward from the respective lower-end horizontal portions of the
legs
41a and
41b. FIG. 7B shows one of the slidingly-attaching
projections
311c in enlarged scale, from which it is seen that the
slidingly-attaching projection
311c has elements similar to those
of the slidingly-attaching projection
31a of FIG. 5B, such as a screw
head
331c, gap portion
321c and flange
341c.
The slidingly-attaching projection
311c is fixed to the corresponding
lower-end horizontal portion of the leg
41b by means of a bolt and
nut connection
312. The four slidingly-attaching projections
311a
to
311d are provided on the legs
41a and
41b
of the roof plate
4 in corresponding relation to the four slide portions
351a to
351d provided on the bottom plate
5.
Although not clearly seen in FIG. 7A, the other slidingly-attaching projections
311a,
311b and
311d are identical in
construction to the projection
311c.
When attaching the rear casing section
3 to the main casing section
2,
the slidingly-attaching projections
311a to
311d in
the embodiment of FIGS. 7A and 7B operate with the corresponding slide portions
351a to
351d in the same manner as the above-described
slidingly-attaching projections
35a to
35d of FIG.
5 operating with the corresponding slide portions
35a to
35d.
Therefore, the operation of the slidingly-attaching projections
311a
to
311d is not described here to avoid unnecessary duplication.
Namely, the presence of the tapered surfaces allow the slide portions
351a
to
351d to be brought into tighter engagement with the slidingly-attaching
projections
311a to
311d as the rear casing section
3 is pushed further relative to the main casing section
2. Note that
a distance D
1 from the upper surface of the slide portions
351a
to
351d to the top of the corresponding side plates
6a
and
6b is greater, by an appropriate clearance C, than a distance
from the flange of the slidingly-attaching projections
311a to
311d
to the lower surface of the roof plate
4; namely, D
1=D
2+C.
With this arrangement, the rood plate
4 can be firmly pressed against the
main casing section
2, which achieves very tight engagement.
In the slidingly-attaching structure, the positions of the slide portions
351a
to
351d, each having the openings and tapered surface, and slidingly-attaching
projections
311a to
311d may be revered from those
illustrated in FIG. 7A. Namely, the slide portions
351a to
351d,
each having the large opening (
36a), elongated opening (
37a),
tapered surface (
39a) and the like, may be provided on the lower-end
horizontal portions of the corresponding legs
41a and
41b
of the roof plate
4, and the slidingly-attaching projections
311a
to
311d may be provided on the corresponding slide members
351
of the bottom plate
5 so as to extend upwardly. Also, in a case where the
slide portions
35a to
35d are provided on the side
plates
6a and
6b as in the example of FIG. 5, the positions
of the slide portions
35a to
35d, each having the openings
and tapered surface, may be reversed from those in the above-described embodiment.
Namely, the slide portions
35a to
35d, each having
the large opening (
36a), elongated opening (
37a), tapered
surface (
39a) and the like, may be provided on the underside of the
roof plate
4, and the slidingly-attaching projections
31a to
31d may be provided on the upper surfaces of the corresponding side
plates
6a and
6b so as to extend upwardly.
In summary, the present invention arranged in the above-described manner can
provide
an electronic keyboard musical instrument having an improved casing structure that
can be assembled with ease in such a manner as to present good appearance in an
assembled state and also facilitates maintenance and inspection of the interior
of the casing.
The present invention relates to the subject matter of Japanese Patent Application
No. 2001-285072 filed on Sep. 19, 2001, the disclosure of which is expressly incorporated
herein by reference in its entirety.
*
