JPS61289390A - Pianissimo mechanism for upright 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] [Industrial Application Field] This invention effectively absorbs the kinetic energy of the rotating and descending muffler support to prevent it from bouncing back, generating noise, etc. This invention relates to a low-tone mechanism for an upright piano that quickly stops at a certain position.

[Conventional technology]

In an upright piano, a muffler felt as a cushioning member is selectively interposed between the strings and the hammer by pedal operation, and the hammer hits the strings through this muffler felt, thereby increasing the impact force. It is equipped with a dampening mechanism that weakens the performance sound. Third
Figures 1 and 4 show a conventional weak sound mechanism of this type.
A muffler support body consisting of a muffler frame 4 that extends commonly to all the strings 3 of each pitch stretched behind the muffler frame 4, and a pair of left and right side frames 5 and 6 that support this muffler frame 4. A muffler felt 7 is suspended from the muffler frame 4 in correspondence with the strings 3 of the valley pitch.

The pair of side frames 5.6 are disposed on the inner surfaces of a pair of left and right parent plates (not shown) constituting each side surface of the piano body via support shafts 8, 9, respectively, so as to be rotatable in the vertical direction, and The side frame 5 is given the habit of always returning upward by a spring 10, and in response to this, the muffler felt 7 is normally placed at a position higher than the No. 1 mark 2, that is, the normal playing position (the solid line position in Fig. 4). ) is stopped. Further, the side frame 5 is connected to a switching means B for selectively switching the seven frames 5 between a normal performance position and a lower weak tone performance position. Switching means B
is the connecting rod 12. Tabular hanging metal 13, link 14. Pedal hanger 15. It is composed of a link 16, a hanger 17, a muffler pedal 18, etc., and the above-mentioned components 12, 13, 14, 15 are
, 16 and 17 in the directions of the arrows, the side frame 5 rotates downward against the spring 10, and at the same time, the side frame 6 on the treble side also rotates downward. . As a result, -Ir7:
! )-7 Elt 7 is rotated and lowered together with the muffler frame 4 and is set and held at the weak tone playing position (the position indicated by the chain line in FIG. 4), and is interposed between the hammer 2 and the string 3. therefore,
In this state, when you press the key, the hammer 2 will move the key (
(not shown) and hits the strings 3 through the muffler felt 7, the vibrations of the strings 3 are weakened and the performance is soft.

In addition, the bass part 3a and the middle tone value 3b of the string 3 are generally
The bass part 3a crosses in a letter shape, and the bass part 3a is rounded towards the player's side from the middle part 3b near the point where the strings are struck. Located on the side. Furthermore, as the switching means B of the low sound mechanism 1, in addition to the above-mentioned pedal mechanism, there is also known a structure in which the side frame 5 is rotated and lowered by manual lever operation.

[Problem that the invention seeks to solve]

By the way, in the conventional mute mechanism 1 having such a configuration, the muffler support A is positioned and stopped at the mute playing position. The stopper mechanism C is configured with a buffer member 21 fixed to the lower surface of the frame 5.6 and made of felt, etc. However, in such a stopper mechanism C, the repulsion coefficient between the dowel 20 and the buffer member 21 is high, and the muffler support is The kinetic energy of the body A cannot be fully absorbed, and when the muffler support At is rotated and lowered, the buffer member 21 collides with the dowel 20 and bounces back, making it impossible to instantly stop the muffler support at the soft playing position. Moreover, there was a problem in that the collision sound at this time reverberated several times within the piano body, causing discomfort to the player.

[Means for solving problems]

The damping mechanism for an upright piano according to the present invention was made to solve the above-mentioned problems, and includes a muffler support that is rotatably arranged in the vertical direction, and a muffler support that is suspended from the muffler support and is used for normal playing. Sometimes, a muffler felt is set above the hammer and is interposed between the hammer and the strings during soft playing, and by rotating the muffler support, the muffler felt is selected between a normal playing position and a soft playing position. and a damper which is disposed at a soft tone performance position corresponding to the muffler support and receives the 77-piece support which rotates downward.

[Effect]

In this invention, when the link receives the muffler support, it effectively absorbs the kinetic energy of the muffler support by using fluid viscous resistance. It is possible to prevent the generation of noise caused by the noise and to quickly stop the performance at a weak tone performance position.

〔Example〕

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

FIG. 4 is a side view showing an embodiment of the low sound mechanism according to the present invention, and FIG. 2 is a sectional view of the link.

In these figures, a Danno (-31) is attached to the inner surface of the left and right parent plates 30 using fluid viscous resistance (-31) on the bracket 32.
The side 7 frames 5 and 6t which are rotated and lowered by this Danno-31 are arranged respectively through the
The only difference from the conventional mechanism mentioned above is that it stops at the soft playing position.

Since all other points are the same, the same constituent members are designated by the same reference numerals and their explanations will be omitted.

As shown in FIG. 2, the damper 31 includes a sleeve 33 whose lower surface is open, a compression coil spring 34 housed in the sleeve 33, and a compression coil inserted into the sleeve 33 in an inner layer. A plunger 35 is integrally provided with a cylindrical portion 35A that accommodates the lower end of the spring 34, and the outer end is screwed into the screw hole of the bracket 32 and fixed with a nut 36, and a lid based on the lower end opening of the sleeve 33. The body 37 and the felt 38 bonded to the upper surface of the sleeve 33 form an air damper.Normally, the sleeve 33 is set and held at the uppermost position by the spring force of the compression coil spring 34. The sleeve 33
A small hole 39.40 is provided in the upper surface and the felt 38, and the inner peripheral surface of the sleeve 33 and the cylindrical portion 3 of the plunger 36 are connected to each other.
A gap of approximately 0.05 to 0.1 is provided between the outer circumferential surface of 5A and the outer circumferential surface of 5A as a ninth channel for obtaining fluid viscous resistance. However, it does not necessarily have to be a gap, and a groove having a similar cross-sectional area of the flow path may be used, and the cylindrical portion 34A
It may also be a small hole provided on the lower surface of the. An appropriate gap is also provided between the through hole 43 provided at the center of the lower surface of the lid 37 and the plunger 35, and air enters and exits through this gap and the small holes 38, 40. In addition, sleeve 3
3 is normally set and held at a slightly higher position than the dowel 20.

In the weak sound mechanism having such a configuration, the switching means A
(See Figure 3) When the muffler fel) 7 is switched from the normal performance position to the soft performance position, the muffler support A rotates downward as shown by the chain line in Figure N1.
Each side frame 5.degree.6 is first received against the felt 38 of the damper 31, and by pushing down into the sleeve 331, the felt 21 hits the dowel 20 and is stopped at the soft playing position.

Here, the sleeve 33 is pushed down against the fluid viscous resistance between the compression coil spring 34, the inner peripheral surface of the sleeve, and the outer peripheral surface of the cylindrical part due to the collision between the side frames 5 and 6.
To effectively absorb the falling impact of the muffler support A. That is, some of the air in the upper part of the sleeve 33
The air moves to the lower part of the sleeve 33 through the gap between #3 and the cylindrical part 35A, but this gap is sufficiently small, so the fluid viscous resistance when air passes through the gap prevents the sudden fall of the shimmer support A. It brakes in proportion to the backflow and absorbs the falling impact St-. As a result, the muffler support member does not bounce on the felt 38 and quickly stops at the soft playing position.

In this case, the damper 31 is the muffler support A.

Placing it far away from the center of rotation is highly effective in absorbing the kinetic energy of the muffler support A.

Furthermore, if the small holes 39, 40 and the through holes 43 are made smaller by -r, most of the air inside the sleeve 33 will be removed from the sleeve 33.
Since the amount of air that moves inside the 3O and enters and exits from the outside is significantly reduced, the fluid sound emitted to the outside is reduced.

In addition, in the above embodiment, in addition to the damper 31, the damper mechanism C was provided which consisted of the dowel 20 and the felt 21, but the present invention is not limited to this.The muffler support A is received and supported only by the damper 31. Of course, it is possible.

Further, in the above embodiment, the small hole 39 is provided on the upper surface of the sleeve 33, but if the small hole 39t is not provided and air is allowed to enter and exit only through the through hole 43, the intrusion of air pockets etc. can be reduced. be able to. It's nine.

At that point, due to the compressibility of air, when the air in the upper part of the sleeve is compressed, the air in the lower part is depressurized, and there is a risk that air will momentarily enter the lower part of the sleeve from the outside through the through hole 431. Therefore, the gap between the inner peripheral surface of the sleeve and the outer peripheral surface of the cylindrical portion and the hole diameter of the through hole should be determined with this point in mind.

Furthermore, although an air damper is used as the damper 31 in the above embodiment, it may be filled with an incompressible liquid, and 4I may be of any type as long as it utilizes a fluid viscous antibody.

〔Effect of the invention〕

As stated above, the damping mechanism of the upright piano according to the present invention is configured so that the rotating and descending muff 2-support is received by the damper and its kinetic energy is absorbed, so the vibration absorption effect is large and the muffler It is possible to prevent the support from rebounding and to generate noise, and to quickly stop the performance at a soft playing position. Therefore, switching during performance is possible. Also, the structure is simple and installation is easy.

[Brief explanation of drawings]

FIG. 1 is a side sectional view showing an embodiment of a low sound mechanism according to the present invention. FIG. 2 is an enlarged sectional view of the damper, M3rBJ is a perspective view showing an example of a conventional weak sound 1I Sakaki, and FIG. 4 is a side sectional view of the main part of the same mechanism. 2...Hemmer, 3@---string. Book 4 - 77 ra 7 rem. 5.6.Fist: Side frame, 31..Damper, A..Muffler support, B..Switching means. C...-Fist stopper mechanism.

Claims (1)

[Claims] A muffler support is arranged to be freely rotatable in the vertical direction, and the muffler is suspended from the muffler support and is set above the hammer during normal performance, and is interposed between the hammer and the strings during soft play. a muffler felt, a switching means for selectively switching the muffler felt between a normal performance position and a low-pitched performance position by rotating the muffler support, and a switching means disposed in the low-pitched performance position corresponding to the muffler support; A damping mechanism for an upright piano, comprising a damper that receives the muffler support as it rotates and descends.