JPS614099A - Sound volume adjustor for piano - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention effectively reduces the sound played by cutting off the vibration transmission path from the bridge, which is the member closest to the strings that produce the sound, to the soundboard. This invention relates to a volume control device for a piano that allows performance.

[Prior art]

Traditionally, pianos have been constructed to have a soundboard with a large surface area and produce a large volume of sound, so when practicing at home, etc., the volume of the performance should be adjusted to avoid noise pollution to the surrounding area. It is equipped with a damping mechanism that makes the sound sufficiently quiet during normal performance. This type of weak sound mechanism includes one in which a buffer member is selectively interposed between the string and the hammer;
One that reduces the hammer speed (% Kosho 48
-19246 Publication), one in which a piano is installed in a soundproof room (Japanese Unexamined Patent Application Publication No. 55-57894), and one in which a back cover with a sound-insulating structure is provided on the back of the cabinet so that it can be opened and closed (Japanese Utility Model Publication No. 54-1989). Various proposals have been made, including Japanese Patent No. 14524).

However, in a weak sound mechanism in which a buffer member is interposed between the string and the hammer to weaken the string-striking force of the hammer,
Since the strings are hit through a buffer member, even the sound quality changes,
The pianissimo was very strong, and at 6:00, the weak tone effect was insufficient.

The low tone device disclosed in Japanese Patent Publication No. 48-19246 has problems with the feel of the key touch and the rapid repeated hitting performance. The soundproof room according to Japanese Patent Publication No. 55-57894 can eliminate the influence on the surroundings because the sound does not leak outside, but it has the disadvantage that the construction cost of the soundproof room is high and it requires a large site. Ta. On the other hand, Utsukai Showa 54-1452
The piano in Publication No. 4 has a back cover that insulates the sound, so it is inexpensive.
Although it can be installed in a normal room, since it does not reduce the generated sound volume itself, shadows on the surrounding area cannot be avoided.

[Summary of the invention]

This invention was made in view of the above points,
The soundboard is arranged so as to be rotatable in the direction of approaching and separating from the frame, the pieces are separated from the soundboard, the soundboard is moved closer to the frame during normal performance and connected to the pieces, and the soundboard is moved when playing at a weak tone. With an extremely simple configuration in which the pieces are held by the frame and kept away from the frame and pieces, it is possible to effectively attenuate the sound of the piano performance, and the sound quality and key touch feel are the same during normal performance and at low pitch. To provide a piano volume control device that can maintain the same volume.

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

〔Example〕

Figure 1 is a side cross-sectional view of the volume control device according to Kamei applied to an upright piano in a soft playing state, Figure 2 is a cross-sectional view along the line ■-■ in Figure 1, and Figure 3 (&) ,
(b) is an enlarged sectional view taken along the line m-u'r in FIG. 2, (IL) is in a weak tone performance state, (b) is in a normal performance state, and FIG. 4 (a).

(b) is a sectional view taken along the line IV-TV in FIG.
b) is an enlarged sectional view taken along the line V-V in FIG. 2, in which (a) shows a soft playing state and (b) shows a normal playing state. In these figures, 1 indicates a pair of left and right parent plates 2, 3, a bottom plate 4, a large base 5,
A cabinet formed into a vertical box shape with an upper front panel, a lower front panel, a ceiling panel, etc. (not shown), and a keyboard consisting of a large number of keys (not shown) arranged in parallel at the center of the front of the cabinet 1. part 6 is integrally protruded, and inside is a well-known action mechanism and damper mechanism (none of which are shown) that operate in conjunction with a duplicate key, a frame 8 with a large number of strings 7 stretched, and a sound system. A board 9, pieces 10 (10A, 10B), etc. are stored and arranged.

The frame 8 is formed into a picture frame shape by casting such as cast iron, has a plurality of openings 11, reinforcing ribs 12, piece holes 13 through which pieces 10 pass, etc., and is arranged vertically. , its upper end is firmly fixed to a pin plate 14 arranged and fixed above the interior of the cabinet 1, and its both side edges are connected to each main plate 2.
, 3 is firmly fixed to the inner surface. In this case, the structure for fixing the frame 8 to the main plates 2 and 3 is usually fixed at several locations on the side edges of the frame 8 with setscrews 15 as shown in FIG. As shown in FIG. 7, it is preferable to fix it via a vibration isolating member 16 made of rubber or the like. In FIGS. 6 and 7, 1T is a frame fixing member 1.18, 19 is a bracket, and 20 is a connecting bolt, and this bolt 20 is screwed into a nut (not shown) embedded in the vibration isolating member 16. has been done.

The soundboard 9 is disposed at the rear of the frame 9 by having its peripheral edge fixed to a frame-shaped support main body 21 via a bolt 22, and the upper end of the support support main body 21 is A strut mounting member 2 arranged and fixed on the back surface of the pin plate 14
3 via a hinge 24 so as to be rotatable in the front-back direction. Therefore, the soundboard 9 is not integrally connected to the frame 8 (general pianos are connected), but is rotated with respect to the frame 8 by an appropriate rotation mechanism when switching between normal performance and soft-tone performance. The two pieces are constructed so that they can be moved closer to each other and separated from each other, and are also constructed separately from the piece 10, so that they are integrally connected only during normal performance. Note that, on the back surface of the soundboard 9, a plurality of hammer bars 26 are arranged as in the conventional structure.

An example of the rotation mechanism will be described in detail based on FIGS. 3 and 8. The rotation mechanism 30 is composed of a rotation operation shaft 31, a nut member 32, a pair of left and right operating rods 33, 34, etc. There is. The rotary operation shaft 31 is located between the loud pedal 35 and the soft pedal 36 and passes through the large base 5;
A knob S1m is formed at the outer end, and a threaded portion 31b that is screwed into the threaded hole of the nut member 32 is formed on the outer periphery of the inner end. The nut member 32 is fixed on the bottom plate 4 and has a fitting groove 3B, into which a slider 40 rotatably attached to the tip of the rotary operation shaft 31 is slidably fitted. has been done. The pair of operating rods 33 and 34 are arranged substantially in a straight line in the left-right direction along the upper surface of the bottom plate 4, and are held at intermediate portions by holding members 41 and 42 disposed on the bottom plate 4, respectively. The inner end is commonly rotatably connected to the slider 40 by a thumbscrew 45, and the outer end is connected to both sides of the lower end of the column main body 21 by connecting rods 46. 47
are connected via. The connecting rods 46 and 47 are inserted into holes (not shown) in support plates 48 and 49 provided on the inner surfaces of the respective parent plates 2 and 3.

Therefore, the rotary operation shaft 31 is rotated by arrow A in FIG.
When the operating shaft 31 is rotated in the loosening direction shown by , the operating shaft 31 is aligned along the threaded hole of the nut member 32, so the slider 40 also moves together with the operating shaft 31, and thereby the pair of operating rods 33, 34 are rotated clockwise and counterclockwise about the holding members 41 and 42, respectively. Then,
The pair of left and right connecting rods 46 and 47 are moved rearward, and the support main body 21 is accordingly rotated rearward about the hinge 24 (see FIG. 1), so the soundboard 9 is moved away from the frame 8. , the state is switched to a soft playing state.

FIG. 1 and FIG. 3(a) show this state. Conversely, when the rotary operating shaft 31 is rotated in the tightening direction indicated by arrow B in FIG. Strut body 2
1, the soundboard 9 approaches the frame 8 and is switched to the normal performance state. Note that 50 and 51 are stoppers that restrict forward rotation of the support main body 21.

The bridge 10 is composed of a long bridge 10A to which the low and middle strings are passed, and a short bridge 1OB to which the high strings are passed. As shown in the fourth section, the long piece 10A has a lower end portion υ smaller in width than an upper end portion, and has a four portion 60 formed at the center of the upper surface over the entire length in the longitudinal direction, and passes through the elongated hole 13 of the frame 8. On both sides, a plurality of platens (61, 62) formed in a substantially inverted shape are fixed at appropriate intervals in the longitudinal direction of the long piece 10A, and horizontal portions (61 & 62) of the platens (61, 62) are fixed at appropriate intervals in the longitudinal direction of the long piece 10A. , e2a has a damping material 6 made of rubber or the like.
3°64 are fitted and fixed respectively. On the other hand, the portions corresponding to the damping materials 63 and 64 on both side edges of the elongated hole 13 have piece body stop portions 6T that receive and hold the elongated bridge 10A when the playing state is switched to a soft tone playing state. It consists of This piece body stopper 6T is approximately 45mm long on the frame surface side.
It has a pair of slopes 66b formed at an angle of 13° and facing each other across the elongated hole 13 and having opposite inclination directions. The side tips are also cut off diagonally at the same inclination angle.In this case, in the normal performance state, the soundboard 9 approaches the frame 8 as shown in FIG. The damping materials 63 and 64 are sloped in order to integrally connect with the long bridge 10A and move the long bridge 10A forward against the string pressure of the strings 7.
m, spaced from 68b. When this state is switched to a soft playing state, the soundboard 9 gradually moves away from the frame 8 as shown in FIG. 4(a), so the long bridge 10
A also retreats together with the soundboard 9, and on the way, the damping materials 63 and 64 come into contact with the slopes 66m and 66b, and the long piece 1
While the bridge 0A is locked by the bridge stopper 67 of the frame 8, the long bridge 10A is released from this coupled state because the soundboard 9F continues to move backward. In this state, the damping material 6
3.64 is pressed against the bridge body stop portion 6γ due to string pressure, so there is no risk that the long bridge 10A will fall off from the frame 8. Further, since the slopes of the damping materials 63 and 64 are pressed against the slopes 661L and 66b, the long piece 10A can be positioned and fixed, and displacement in the lateral direction can be prevented.

Note that 69 in FIG. 4 is a string suppressing member that is provided integrally or integrally with the frame 8 and presses the strings 7 toward the long bridge 10A.

Referring to FIG. 5, the coupling means 70 between the soundboard 9 and the long bridge [OA] will be described in detail.
A plurality of male coupling members 73 are buried at appropriate intervals in the longitudinal direction of the long bridge 10A, and a female coupling member T4 is disposed on the soundboard 9 in correspondence with each male coupling member 73. It is equipped with The male coupling member T3 is integrally formed of plastic or the like, and the protrusion protruding from the back surface of the long piece 10A has a hollow abacus shape that opens toward the female coupling member 74 and is elastic. It constitutes a retaining portion 73A. Further, a C-shaped spring 76 having elastic force in the direction of diameter expansion is fitted inside the retaining portion 73A. On the other hand, the female coupling member 74 is fitted and fixed into a mounting hole 77 formed in the soundboard 9, and has an engagement recess 78 formed in its surface into which the engagement portion 73A can fit. This engagement recess T
The opening diameter of No. 8 is set smaller than the maximum diameter of the retaining portion 73A, so that when the normal performance state is switched, the retaining portion 73A
are press-fitted by their own elastic deformation, and after being fitted, they are restored to their original state by the force of the spring 76, so that they do not easily come off.

Since the short piece 10B is also constructed in the same manner as the long piece 10A described above, a detailed explanation thereof will be omitted, but the short piece 10B is sufficiently shorter than the long piece 10A. Yu2 engineering. Year 7, yes. Engineering. K7L/-A8 is held by the piece locking part (representing the same structure as the piece locking part of the long piece 10A), and during normal performance, one or two coupling means (the piece locking part of the long piece 10A) is attached to the soundboard 9 during normal performance. (has the same structure as the coupling means TO)
is configured to be connected via. In addition, the short bridge in general pianos has an overhang structure with arms and legs and a bridge base, but in this invention, it has arms and legs and a bridge connection, so the height of these two members is It is formed higher than the long piece 10A.

In a piano having such a configuration, during normal performance, the soundboard 9 is set and held at a position close to the frame 8,
Because it is integrally combined with the long piece 10A and the short piece 1OB,
When the string 7 is struck with a hammer (not shown) in this state, the vibration is transmitted to the soundboard 8 via the long bridge 10A or the short bridge 10B and is amplified. Therefore, a loud performance sound can be obtained.

On the other hand, when switching from the normal playing state to the soft playing state, the soundboard 9 moves away from the frame 8 and at the same time the long bridge 10A
This connection between the short bridge 10A and the short bridge 10B is released, and string vibrations are no longer transmitted to the soundboard 9 from the long bridge 10A or the short bridge 10B. Therefore, even if you hit the string 7, the vibration will be transmitted to the soundboard 9.
The sound of the piano performance is not amplified, and the sound of the piano performance is sufficiently attenuated compared to that of a normal performance. In addition, in a soft playing state, the long bridge 10A and the short bridge 10B move back due to string pressure, and the chest height becomes almost zero and is held by the frame 8 via the damping material 63, 64. vibration transmission can be minimized.

As a result, the tonic tone can be made smaller. Furthermore, even when playing a soft tone, the string T is directly struck by the hammer, so the sound quality and key touch feel are unchanged from when playing normally.

In addition, although the above-mentioned example was explained about the case where it was applied to an upright piano, the present invention is not limited to this, but can also be applied to a grand piano.

Furthermore, it goes without saying that the present invention is not limited to the structure of the above-described embodiment, and that the means for connecting the soundboard 9 and the bridge 10, the rotating mechanism for the soundboard 90, etc. can be modified as appropriate.

〔Effect of the invention〕

As explained above, in the piano volume control device according to the present invention, the soundboard is rotatably arranged and the pieces are separated from the soundboard, and the soundboard is rotated toward the frame during normal performance and the pieces are connected to each other. The bridge is connected integrally, and when playing a soft tone, the soundboard is rotated in the direction away from the frame to break the connection between the bridges, and the bridge is fixed to the frame via the damping material using string pressure. It is possible to effectively attenuate the sound of a piano performance without inhibiting vibration or hammer movement. Therefore, even when the tone is muted, the sound quality and key touch feel do not change, the amount of sound stopped during soft tone performance can be reduced, and the switching operation is simple, so the effects are very great.

[Brief explanation of the drawing]

FIG. 1 is a side cross-sectional view of an upright piano equipped with a volume control device according to the present invention in a soft-playing state, FIG. 2 is a cross-sectional view taken along the line ■--■ in FIG. 1, and FIG. 3(a). (b) is an enlarged sectional view taken along the line ■-■ in Fig. 2, (a) is in a weak tone performance state, (b) is in a normal performance state, and Fig. 4 (a), (
b) is a sectional view taken along the line mV-IV in Figure 2, where (a) is a weak tone performance state, (b) is a normal performance state, and Figures 5 (a) and (b).
) is an enlarged cross-sectional view taken along the line V-V in Figure 2, (,) is a soft playing state, (b) is a normal playing state, Figure 6 is a sectional view of the main part showing the frame fixing structure, and Figure 7 is the frame. FIG. 8 is a front view of the main part showing another fixing structure, and is a sectional view taken along the enlarged line 1--2 in FIG. 3(b). 2...Fist gear vignette, T...string, 8...frame, 9...ΦIl plate, 10...piece, 10A...
...long piece, IOB...-short piece, 13...long hole,
30・Fist・φ rotation mechanism, 63.64・・・Dumping material, 6T・・・Block body stop part, ' ro・・・Connection means.

Claims (1)

[Claims] A frame having a bridge locking portion, a soundboard disposed rotatably in a direction toward and away from the frame, and a bridge disposed detachably from the soundboard, During normal performance, the bridge is connected to the soundboard and separates from the bridge locking portion of the frame, and when the soundboard is rotated in a direction away from the frame during soft playing, the bridge separates from the soundboard and reduces string pressure. A volume control device for a piano, characterized in that the device is press-locked to the bridge locking portion.