JP4912276B2 - Piano silencer, piano with silencer - Google Patents

Description

  The present invention relates to a piano silencer that can be attached to an acoustic piano such as a grand piano, in which sound is generated electronically in response to a key press, instead of generating sound from a string by preventing hammering of the string, and The present invention relates to a piano with a silencer equipped with the piano silencer.

First, the mechanism of the piano silencer will be briefly described with reference to FIG. In addition, the structure of the arm 23 of the piano silencer described below is not a known technique, a technique that is publicly implemented, or a technique that is known by literature.
A rotating shaft 12 is disposed in a space between the string 10 and the hammer shank 11, and a muffler bar 13 protrudes in one direction from the peripheral surface of the rotating shaft 12. The rotation shaft 12 is rotatably supported by the arm 23 and is rotated by a rotation mechanism (not shown). The structure of the arm 23 will be described later. The muffler bar 13 moves between the first rotation position and the second rotation position as the rotation shaft 12 rotates. In FIG. 4, the position of the muffler bar 13 indicated by a solid line is a state where the rotation shaft 12 is positioned at the first rotation position, and the position of the muffler bar 13 indicated by a dashed line is the position of the rotation shaft 12. This is a state located at the second rotation position.

  When the muffler bar 13 is located at the first rotation position (this case is referred to as “mute mode”), the hammer shank 11 jumps up by the key depression, but the hammer 14 provided at the tip of the hammer shank 11 The hammer shank 11 hits the muffler bar 13 before hitting the string 10. Accordingly, in this case, since the hammer 14 does not strike the string 10, no sound is generated from the string 10. In FIG. 4, the hammer shank 11 and the hammer 14 at the time of a collision with the sound deadening bar 13 are indicated by a two-dot chain line. In the mute mode, a key depression detection switch (not shown) detects the presence / absence and strength of the key depression and electronically generates a sound corresponding to the key depression mode.

On the other hand, when the muffler bar 13 is located at the second rotation position (this case is referred to as “acoustic mode”), the hammer shank 11 jumps up by the key depression, but the hammer shank 11 hits the muffler bar 13. Absent. Therefore, in this case, the hammer 14 provided at the tip of the hammer shank 11 strikes the string 10 as in the case where the piano silencer is not attached, thereby generating a sound from the string 10.
In this way, the performer of the piano with a muffler can freely select the mute mode and the acoustic mode by means for switching the rotation position of the rotation shaft 12.

Next, the structure of the arm 23 will be described with reference to FIGS. 4 and 6. The arm 23 includes a turning arm 231 that supports the turning shaft 12 and can be turned when the piano silencer is attached, and a turning arm fixture 232 that is attached to the piano and fixes the turning arm 231. .
The rotating arm fixture 232 includes two flat plate portions facing each other and a connecting portion 232b that connects the flat plate portions. In this example, a single metal plate is bent into a U-shape. Is formed. The notch 232 c formed in the flat plate portion is engaged with the hammer rail 25. Then, the rotary arm fixture 232 and the hammer rail 25 are fixed by abutting the tip of the screw 232e screwed into the female screw cut in the first hole 232d formed in the connecting portion 232b with the hammer rail 25. Is done. Further, the screw 232e is fixed by the double nut effect of the nut 232f and the connecting portion 232b to prevent loosening.

As shown in FIG. 7, the plurality of hammer shanks 11 and the plurality of hammers 14 are arranged in the extending direction of the hammer rail 25, but a slightly wider space s is vacant between the adjacent hammer shanks 11. There are several places. The rotating arm fixture 232 is installed at both ends of the space s and the hammer rail 25, respectively.
The description will be given with reference to FIGS. 4 and 6 again. The rotating shaft 12 is rotatably supported at the tip of the rear protruding portion 231a located on the back side (hammer 14 side) of the piano of the rotating arm 231. A rotation support shaft 231 c is provided on the central protrusion 231 b of the rotation arm 231 so as to protrude perpendicularly to the surface of the rotation arm 231. The rotation support shaft 231 c is threaded on the outer periphery thereof, is inserted into a hole 232 a formed in the rotation arm fixture 232, and is fastened by a nut 233. The diameter D of the hole 232a is larger than the diameter d of the rotation support shaft 231c.

An internal thread is cut in the second hole 232d ′ formed in the connecting portion 232b of the rotating arm fixture 232. The screw 234d is inserted into the hole 234e of the fixing plate 234, and is screwed into the hole 234d ′ that is the female screw. As a result, the fixing plate 234 is fixed to the rotating arm fixture 232.
A bent portion 231e is formed at the front protruding portion 231d of the rotating arm 231, and a screw 231f is provided to protrude from the bent portion 231e. The screw 231f is screwed into a nut 234b located on the back side of the fixed plate 234 and inserted into a hole 234a formed in the fixed plate 234. The rotation arm 231 tends to rotate clockwise on the paper surface of FIG. 4 around the rotation support shaft 231c due to its own weight, the weight of the rotation shaft 12, and the silencer bar 13. However, the nut 234b screwed to the screw 231f hits the fixed plate 234, and the rotation of the rotation arm 231 is prevented.

With this configuration, if the mounting position of the nut 234b to the screw 231f is changed, the rotation preventing position of the rotating arm 231 can be changed. As a result, the position of the rotating shaft 12 and the sound deadening bar 13 in the height direction is changed. Can be adjusted. When the position of the sound deadening bar 13 is determined, the front and back of the fixing plate 234 are sandwiched and fixed by the nut 234b and the nut 234c located on the front side of the fixing plate. Thereby, the position of the rotation arm 231 and the muffler bar 13 is fixed.
The silencing bar support position fine-tuning means including the screw 231f, the fixing plate 234, the nuts 234b and c, and the screw 234d has a function of finely adjusting the positions of the rotating shaft 12 and the silencing bar 13 as described above.

Thus, the turning arm 231 is fixed to the turning arm fixture 232 via the turning support shaft 231c and the fixing plate 234. On the other hand, the nut 233 (see FIGS. 6 and 7) fastened to the rotation support shaft 231c is loosened, and the rotation of the rotation arm 231 and the rotation arm fixture 232 by the fixing plate 234 is released, thereby rotating the rotation. The rotation arm 231 can be rotated around the dynamic support shaft 231c. Thereby, there exists a merit that the attachment work and removal work of the silencer of a piano become easy.
In the state where the piano silencer is attached, the heights of the pin plate 28 and the silencer bar 13 substantially coincide as illustrated in FIG. In this case, if the pin plate 28 and the sound deadening bar 13 collide with each other when moving in the direction of pulling out toward the front side of the piano, the base 27 on which the bracket 26 for fixing the hammer rail 25 is installed is placed on the left and right sides in FIG. Cannot move in the direction.

  Here, at the time of mounting / removing the piano silencer and at the time of tuning, the rotating arm 231 is rotated in the direction in which the rear protruding portion 231a approaches the base 27 as illustrated in FIG. Let Accordingly, the base 27 on which the bracket 26 for fixing the hammer rail 25 is installed can be moved in the left-right direction on the paper surface of FIG. 5 without the pin plate 28 and the sound deadening bar 13 colliding with each other. As a result, the work of attaching / detaching the arm 23 to / from the hammer rail 25 and the sound adjustment work during tuning can be performed in a wider space rather than a narrow space between the pin plate 28 and the base 27.

  Here, as shown in FIG. 7, the rotating shaft 12 and the muffler bar 13 are arranged in parallel to the extending direction of the hammer rail 25 (or the arrangement direction of the hammer shank 11 and the hammer 14). That is, the distance X from the hammer rail 25 of the axis of the rotating shaft 12 on the lowest pitch side is equal to the distance X from the hammer rail 25 of the axis of the rotating shaft 12 on the highest pitch side. It had been. The right side in FIG. 7 is the treble part side, and the left side is the bass part side.

  It is known that the hammer shank 11 arranged on the high-pitched portion side has a greater flexion when colliding with the silencer bar 13. This is because the hammer 14 ′ disposed on the high sound portion side is smaller and lighter than the hammer 14 disposed on the low sound portion side illustrated by a solid line or a two-dot chain line, as illustrated by a dotted line in FIG. 2. For this reason, the speed of the hammer 14 ′ disposed on the high sound part side that is flipped up by the wipen is faster than the speed of the hammer 14 disposed on the low sound part side, and the hammer 14 ′ disposed on the high sound part side This is because the kinetic energy possessed is greater than the kinetic energy possessed by the hammer 14 disposed on the bass portion side.

Therefore, as in the case of the piano silencer described in the background art described with reference to FIG. 7, when the rotating shaft 12 and the silencer bar 13 are arranged parallel to the extending direction of the hammer rail 25, In consideration of the bending of the hammer shank 11 arranged on the part side, it is necessary to arrange the rotating shaft 12 and the muffler bar 13.
Therefore, the piano silencer of the background art has a problem that the let-off dimension is widened, and the natural key press feeling is impaired accordingly.
The let-off dimension is the distance between the string 10 and the hammer 14 when the hammer 14 and the hammer shank 11 are fired by the wipen. Although it is away from 10, it is the distance between the string 10 and the hammer 14 at this time.

  An object of this invention is to provide the silencer of a piano and the piano with a silencer which can obtain a natural key press feeling.

According to a first aspect of the present invention, there is provided a piano silencer, comprising: a pivot shaft disposed between the string and the hammer shank; and a first projection of the pivot shaft that protrudes in one direction from a circumferential surface of the pivot shaft. The hammer provided at the tip of the hammer shank in the rotating position prevents the hammer from striking the string by colliding with the hammer shank before hitting the string, and the hammer is in the second rotating position of the rotating shaft. A silencer bar that does not prevent hitting and an arm that supports the rotating shaft. When there is a rotation shaft at the first rotation position, the rotation shaft is disposed so that the hammer shank disposed on the high sound portion side collides with the silencer bar at a position closer to the hammer. The arm includes a rotation arm that supports a rotation shaft and can be rotated when the piano silencer is attached, and a rotation arm fixture that fixes the rotation arm. The tool is attached to a hammer rail that rotatably supports the hammer shank, arranged in the extending direction.
According to a second aspect of the present invention, there is provided a piano silencer, comprising: a pivot shaft disposed between the string and the hammer shank; and a first projection of the pivot shaft that protrudes in one direction from a circumferential surface of the pivot shaft. The hammer provided at the tip of the hammer shank in the rotating position prevents the hammer from striking the string by colliding with the hammer shank before hitting the string, and the hammer is in the second rotating position of the rotating shaft. A silencer bar that does not prevent hitting and an arm that supports the rotating shaft. When there is a pivot shaft in the first pivot position, the pivot shaft can pivot the hammer shank so that the hammer shank arranged on the high sound side collides with the silencer bar at a position closer to the hammer. It is inclined with respect to the extending direction of the supporting hammer rail. In the second aspect of the present invention, the piano is a grand piano.
The piano with a silencer of the present invention includes the above-described piano silencer.

  By arranging the rotation shaft so that the hammer shank arranged on the high sound side collides with the silencer bar at a position closer to the hammer, the bending of the hammer shank that occurs when it collides with the silencer bar can be reduced. it can. Thereby, the muffler bar can be arranged at a position close to the string, and the let-off dimension can be narrowed. Therefore, a more natural key pressing feel can be obtained.

The piano silencer according to the present invention is different from the piano silencer described in the Background Art section only in the arrangement of the rotary shaft 12 and the structure for the arrangement. Therefore, below, it demonstrates focusing on the different part. Since other parts are the same as those of the piano silencer described in the background art section, description thereof is omitted.
An embodiment of a piano silencer according to the present invention will be described with reference to FIGS. FIG. 1 is a schematic plan view of a piano silencer according to the present invention, and FIG. 2 is a side view thereof.

As shown in FIG. 1, a plurality of rotating arm fixtures 232 (in this example, five rotating arm fixtures 232) are attached from the low sound portion side to the high sound portion side of the hammer rail 25. In FIG. 1, the right side is the high sound side, and the left side is the low sound side.
A spacer 40 is provided on the side surface of the hammer rail 25 where the rotating arm fixture 232 is attached (hereinafter referred to as a contact surface c1). For example, the spacer 40 is bonded and fixed to the contact surface c1. As a result, the rotating arm fixture 232 is attached to the hammer rail 25 via the spacer 40.

Here, the side surface of the hammer rail 25 is the rear end surface of the hammer rail 25. “Backward” is the direction in which the hammer shank 11 extends when the hammer shank 11 and the sound deadening bar 13 collide, and the direction from the hammer shank 11 toward the hammer 14 (in other words, the tip direction of the hammer shank 11). That is.
The thickness of the spacer 40 provided on the high sound portion side is increased. Thereby, the rotation arm fixture 232 attached to the treble part side is disposed rearward. Therefore, the pivot arm 231 is also arranged rearward as it is located on the high sound side.

Thereby, the rotating shaft 12 rotatably supported by the rotating arm 231 is inclined with respect to the extending direction of the hammer rail 25 (or the arrangement direction of the hammer shank 11 and the hammer 14). That is, as illustrated in FIG. 1, the distance α from the hammer rail 25 of the axis of the rotary shaft 12 on the lowest sound side is from the hammer rail 25 of the axis of the rotary shaft 12 on the highest sound side. It becomes smaller than the distance β.
In this way, by tilting the rotating shaft 12 with respect to the extending direction of the hammer rail 25, the hammer shank 11 arranged on the high-pitched portion side collides with the silencer bar 13 at a position closer to the hammer 14. Become.

Therefore, it is possible to reduce the bending that occurs when the hammer shank 11 disposed on the high-pitched portion side collides with the silencer bar 13. Thereby, the muffler bar 13 can be disposed at a position close to the string 10, and the let-off dimension can be narrowed. Therefore, a more natural key pressing feel can be obtained.
If the rotating shaft 12 and the muffler bar 13 are disposed too far, the hammer 14 collides with the muffler bar 13 before the hammer shank 11 bounced up by the key depression collides with the muffler bar 13, and performance is impossible. It becomes. Therefore, it is desirable to arrange the rotating shaft 12 and the muffler bar 13 at a position that is as far back as possible but does not collide with the hammer 14.

  Here, as illustrated in FIG. 2, since the width of the hammer shank 11 of the hammer 14 ′ on the treble portion side is smaller than the width of the hammer 14 on the bass portion side, the hammer shank 11 on the treble portion side is hammered as much as possible. The rotating shaft 12 and the muffler bar 13 can be arranged further rearward so as to collide with the muffler bar 13 at a position closer to 14.

[Modifications, etc.]
It should be noted that the shape of each rotary arm fixture 232 may be changed so that the rotary arm fixture 232 attached to the high-pitched portion side of the hammer rail 25 supports the rotary arm 231 so that the rotary arm 231 can be rotated rearward. . For example, as illustrated in FIG. 3, the rotation arm fixture 232 attached to the high-pitched portion side of the hammer rail 25 is inserted with the contact surface c <b> 2 that contacts the side surface of the hammer rail 25 and the rotation support shaft 231 c. The distance d1 in the horizontal direction from the center of the hole 232a is increased.

Thereby, even if the spacer 40 is not provided, the rotating arm 231 disposed on the high sound part side is disposed on the rear side, so that the rotating shaft 12 and the muffler bar 13 are also disposed on the rear side as going to the high sound part side. . Therefore, the hammer shank 11 on the high sound part side collides with the silencer bar 13 at a position closer to the hammer 14.
Further, the rotation arm 231 disposed on the high sound side is closer to the position where the rotation support shaft 231c is provided and the center of the hole 23a into which the rotation shaft 12 is inserted between the hammer shank 11 and the sound deadening bar 13. The shape of each rotating arm 231 may be changed so that the distance in the extending direction of the hammer shank 11 is increased.

[Supporting mechanism of rotating shaft 12]
The following support mechanism 22 may be used as a support mechanism that supports the rotating shaft 12. Hereinafter, the support mechanism 22 will be described with reference to FIG. The support mechanism 22 includes an arm 23 and a bearing 24.
An internal thread is cut on the inner peripheral surface of the hole 23 a formed in the arm 23.
The bearing 24 includes a substantially cylindrical bush 241 and a cushioning material 242 provided on the inner peripheral surface of the bush 241. The bush 241 is made of a resin such as metal or nylon, for example. 9A to 9C illustrate a plan view, an α-α sectional view, and a bottom view of the bush 241, respectively. The outer peripheral surface 241a of the bush 241 is cut with a male screw corresponding to the female screw cut on the inner peripheral surface of the hole 23a. A flange 241b is formed at one end of the bush 241, and a groove 241c is formed in the flange 241b at a position at 180 degrees.

The buffer material 242 is made of a fibrous material such as felt, for example, and is affixed to the inner peripheral surface of the bush 241 with an adhesive such as a double-sided tape or a vinyl acetate resin emulsion adhesive. Thereby, the buffer material 242 has a substantially cylindrical shape. The shock absorbing material 242 absorbs the impact received from the hammer shank 11 in which the sound deadening bar 13 and the rotating shaft 12 jump up by the key depression in the sound deadening mode. Further, the buffer material 242 absorbs a position error such as a center deviation between the bush 241 and the rotating shaft 12.
The bearing 24 is screwed into the hole 23 a of the arm 23. The bearing 24 can be easily screwed to the arm 23 by engaging the tool such as a flathead screwdriver with the groove 241 c and rotating the bearing 24. One end of the rotating shaft 12 is inserted into the bearing 24. Thereby, the rotating shaft 12 is rotatably supported by the arm 23 via the bearing 24. The other end of the rotating shaft 12 is also supported by a similar support mechanism.

The support mechanism 22 for the rotating shaft 12 is composed of three parts: an arm 23, a bush 241, and a buffer material 242. For this reason, the number of parts of the support mechanism 22 of the rotating shaft 12 can be reduced, and thereby the number of mounting steps can be reduced. Moreover, the manufacturing cost of components can be reduced by reducing the number of components.
Further, since the support mechanism 22 of the rotating shaft 12 has the bearing 24 directly screwed to the arm 23, the portion supporting the rotating shaft 12 is hardly deformed by an impact. Therefore, the muffler bar 13 can be installed closer to the string 10. Thereby, a let-off dimension can be adjusted narrowly and a more natural key press feeling can be obtained.

  In order to facilitate attachment of the cushioning material 242 to the bushing 241, the bushing 241 may be composed of two parts. For example, as illustrated in FIG. 10, the bush 241 is composed of two substantially semi-cylindrical bodies 241d and e made of resin. FIG. 10 is a diagram illustrating a shape when the bush 241 is configured by two parts. 10A is a plan view of a bush 241 composed of two parts, FIG. 10B is a β-β cross-sectional view of a substantially semi-cylindrical body 241e, and FIG. 10C is an α-α cross-sectional view of a substantially semi-cylindrical body 241d. is there. In this example, the substantially semi-cylindrical bodies 241d and e are connected via the thin portion 241f, and the substantially semi-cylindrical bodies 241d and e and the thin portion 241f are integrally formed.

A buffer material is affixed to the inner peripheral surfaces of the substantially semi-cylindrical bodies 241d and e. The affixing method is the same as that described above. When a cushioning material is affixed to the inner peripheral surface of each of the substantially semi-cylindrical bodies 241d, e, the work at the time of affixing is greater than when a cushioning material 242 is affixed to the inner peripheral surface of the substantially cylindrical bush 241 Since a large space can be taken, the cushioning material can be easily attached.
When the substantially semi-cylindrical bodies 241d and e are combined and integrated with each other, the integrated substantially semi-cylindrical bodies 241d and e constitute the bush 241 and are respectively attached to the substantially semi-cylindrical bodies 241d and e. The cushioning material constitutes the cushioning material 242. By applying an adhesive to the contact surfaces of the substantially semi-cylindrical bodies 241d and e, in other words, the end faces in the circumferential direction of the substantially semi-cylindrical bodies 241d and e, the substantially semi-cylindrical bodies 241d and e are bonded and fixed. Also good.

A convex portion 241g is formed on the contact surface of one of the substantially semi-cylindrical bodies 241d so that the substantially semi-cylindrical bodies 241d and e can be easily combined, and the contact surface of the other substantially semi-cylindrical body 241e is convex. A recess 241h corresponding to the portion 241g may be formed. By engaging the convex portion 241g and the concave portion 241h, positioning at the time of combination becomes easy, and after the combination, the substantially semi-cylindrical bodies 241d and e are difficult to shift.
In addition, you may form the planes 241i and 241j in the outer peripheral surface of the flange of substantially semi-cylindrical bodies 241d and e, respectively. Accordingly, when the substantially semi-cylindrical bodies 241d and e are combined and integrated with each other, as illustrated in FIG. 11C, the flat surfaces 241i and 241j are positioned at 180 degrees on the outer peripheral surface of the flange 241b of the bush 241. Will be formed.

As described above, when the flat surfaces 241i and 241j are formed instead of the groove 241c, the bearings 24 are rotated by holding the flat surfaces 241i and 241j with a tool such as pliers, thereby easily screwing the bearing 24 into the arm 23. Can be combined. In this example, the planes 241i and 241j are formed. Of course, in a combined state, the flanges 241b of the bush 241 are formed in substantially semi-cylindrical bodies 241d and e so that the grooves 241c are formed at positions of 180 degrees. A groove may be formed in each flange.
In the above example, the bearing 24 is screwed into the arm 23, but the bearing 24 may be press-fitted into the arm 23. In this case, it is not necessary to cut screws on the outer peripheral surface 241a of the bearing 24 and the inner peripheral surface of the hole 23a of the arm 23. Further, after inserting the bearing 24 into the hole 23a, the bearing 24 and the arm 23 may be fixed by fastening the bearing 24 with a fastening component such as a nut or a speed nut.

In the above example, the groove 241c and the flat surfaces 241i and 241j are provided in the flange 241b in order to facilitate the rotation of the bearing 24 in the circumferential direction so as to facilitate the engagement of the bearing 24 with the arm 23. In order to facilitate rotation of the bearing 24 in the circumferential direction, the bush 241 may have another shape. For example, the shape of the flange 241b of the bush 241 may be a hexagon as illustrated in FIG. 11A, or a hole may be provided in the end surface of the bush 241 as illustrated in FIG. 11B. FIG. 11 is a plan view of a modified example of the bush 241.
The buffer material 242 may be formed of an arbitrary elastic body such as rubber or sponge instead of the fiber material. Further, the buffer material 242 does not necessarily have to be attached to the entire inner peripheral surface of the bush 241.

  The arm 23 is not necessarily constituted by a flat plate. In the above example, the thickness of the portion of the arm 23 where the hole 23a is formed is a flat plate thickness. However, the thickness of the portion where the hole 23a is formed may be increased in the plate thickness direction. Thereby, the bearing 24 is more stably fixed to the arm 23.

[Support structure of the rotation support shaft 231c]
Note that the support structure illustrated in FIGS. 12 and 13A may be used as a support structure of the rotation support shaft 231c provided on the rotation arm 231.

  A countersink 232 g is formed on the surface of the rotating arm fixture 232 facing the rotating arm 231. The countersink 232g is a tapered hole, that is, a hole whose diameter decreases from the plate surface of the rotating arm fixture 232 toward the inside. For example, the inclination angle of the peripheral surface of the countersink 232g is 45 degrees. In this example, a countersink hole 232g extends from the plate surface of the rotating arm fixture 232 to a predetermined depth, and a hole 232h having a constant diameter is formed after that depth. The hole 232h may be omitted and only the countersink 232g may be provided.

  The tapered bush 30 is fitted into the countersink 232g. As shown in FIG. 14, the taper bush 30 has a substantially truncated cone shape, and a through hole 30a is formed at the center thereof. Further, the taper bush 30 has a notch 30b in a part of its circumference, and the radial cross section is c-shaped. The shape of the peripheral surface of the taper bush 30 is formed so as to match the shape of the peripheral surface of the countersink 232g when fitted. 14A is a bottom view of the taper bush 30, FIG. 14B is a bb cross-sectional view thereof, and FIG. 14C is a plan view thereof. The taper bush 30 is made of polyacetal resin such as Duracon (registered trademark), for example. In this example, the taper bush 30 is made slightly larger than the countersink 232g so that the head of the taper bush 30 protrudes from the countersink 232g when the taper bush 30 is fitted into the countersink 232g.

A self-clinching stud (press-fit screw) is press-fitted into a through hole formed in the central projecting portion 231b of the pivot arm 231 so that the pivot support shaft 231c projects into the central projecting portion 231b of the pivot arm 231. Provided. By using the self-clinching stud as the rotation support shaft 231c, the screw head does not protrude from the plate surface of the rotation arm 231, so that the arm 23 can be arranged in a narrow place.
Further, a cushioning material 31 made of a resin such as polyacetal is provided on the mutually opposing surfaces of the rotating arm 231 and the rotating arm fixture 232.

  The rotation support shaft 231c to which the taper bush 30 is attached is inserted into the countersink 232g and fastened to the nut 233. When the rotation support shaft 231c and the nut 233 are fastened, as shown in FIG. 13A, the force in the direction approaching each other is pushed by the plate surface of the rotation arm 231, and acts on the taper bush 30 and the countersink 232g. The taper bush 30 fits into the countersink 232g, and there is no backlash between the taper bush 30 and the countersink 232g. At the same time, the diameter of the tapered bush 30 having the notch 30b is narrowed by being fitted into the countersink 232g. Therefore, the rotational support shaft 231c and the tapered bush 30 also have a radial force and a force in a direction approaching each other. The backlash between the rotation support shaft 231c and the taper bush 30 is eliminated.

Thereby, it is possible to prevent a radial shift that may occur between the rotation support shaft 231c and the rotation arm fixture 232, and the muffler bar 13 can be disposed near the string 10. Become. Accordingly, the let-off dimension can be narrowed, and thus a natural key pressing feeling and performance feeling can be obtained.
In this example, since the taper bush 30 is larger than the countersink hole 232g, when the taper bush 30 is fitted into the countersink 232g, the head of the taper bush 30 comes out of the countersink 232g. Further, the cushioning material 31 is provided on the surfaces of the rotating arm 231 and the rotating arm fixture 232 facing each other. For this reason, even if the rotation support shaft 231c and the nut 233 are fastened, the rotation arm 231 and the rotation arm fixture 232 are not in contact with each other because they are separated by the taper bush 30 and the buffer material 31.

Accordingly, it is possible to prevent an abnormal noise that may be generated when the rotating arm 231 and the rotating arm fixture 232 come into contact with each other due to an impact received by the sound deadening bar 13 from the hammer shank 11.
Note that the distance between the rotation shaft 12 and the screw 231f is longer than the distance between the rotation shaft 12 and the rotation support shaft 231c. Further, there is a possibility that the displacement between the screw 231f and the fixing plate 234 is not all of the force generated by the impact received by the silencer bar 13 from the hammer shank 11, but of the force, the diameter of the screw 231f. Only the force of the direction component. On the other hand, all of the force generated by the impact received by the silencer bar 13 from the hammer shank 11 is applied to the rotation support shaft 231c.

Therefore, the screw 231f and the fixing plate 234 are not exerted with such a large force that a displacement occurs between the screw 231f and the fixing plate 234 due to the impact received by the silencer bar 13 from the hammer shank 11. Therefore, the same structure as the taper bush 30 and the countersink 232g is not provided between the screw 231f and the fixing plate 234 in this example.
In the above example, the rotation support shaft 231c is provided on the rotation arm 231, but the rotation support shaft 232i may be provided on the rotation arm fixture 232 as illustrated in FIG. 13B. In this case, a countersink 231g is formed on the surface of the rotating arm 231 facing the rotating arm fixture 232. The rotation support shaft 232 i to which the taper bush 30 is attached is inserted into the countersink 231 g and fastened to the nut 233.

In the above example, the self-clinching stud is used as the rotation support shaft 231c. However, any screw other than the self-clinching stud may be used.
For example, as illustrated in FIG. 13C, a flat head screw is used as the rotation support shaft 231c. In this case, a countersunk hole 231h that matches the shape of the countersunk screw is provided in the pivot arm 231, and a pivot support shaft 231c that is a countersunk screw is inserted into the countersunk hole 231h. In this case, the diameter of the countersink 231h is larger than the diameter of the rotation support shaft 231c, but by tightening the rotation support shaft 231c and the nut 233, the countersink 231h and the rotation support shaft 231c are closer to each other. Since the force acts and the radial positions of the countersink 231h and the rotation support shaft 231c are fixed, no play occurs between the rotation support shaft 231c and the rotation arm 231.

Further, as illustrated in FIG. 13D, a head screw such as a pan head screw may be used as the rotation support shaft 231c. In this case, the countersink 231 h is formed not only in the rotating arm fixture 232 but also in the rotating arm 231. The rotation support shaft 231c to which the taper bush 30 'is mounted is inserted into the countersink 231h, the taper bush 30 is inserted into the rotation support shaft 231c, and further inserted into the countersink 232g. As a result, the tapered bush 30 ′ that matches the shape of the countersink 231 h is also fitted into the countersink 231 h.
The rotation support shaft 231c and the nut 233 are fastened, so that the backlash between the rotation support shaft 231c and the rotation arm fixture 232 can be prevented for the same reason. The backlash between the shaft 231c and the rotating arm 231 can be prevented.

In the above example, the taper bush 30 has a shape larger than the countersink 232g so that the head of the taper bush 30 is protruded from the countersink 232g and is buffered on the mutually opposing surfaces of the rotary arm 231 and the rotary arm fixture 232. By providing the material 31, the rotation arm 231 and the rotation arm fixture 232 were made non-contact. However, the pivot arm 231 and the pivot arm fixture 232 are not necessarily in non-contact.
In the above example, the rotary arm fixture 232 has two flat plate portions that are formed by bending a metal plate into a U-shape, but the shape of the rotary arm fixture 232 is as follows. It is not limited to this. For example, the rotating arm fixture 232 may be formed of a single metal plate having a sufficient thickness.

  In the above example, the rotary arm fixture 232 is attached to the hammer rail 25, but the rotary arm fixture 232 may be attached to the bracket 26.

The top view which shows the outline of the silencer of the piano by this invention. The schematic diagram which looked at the silencer of the piano by this invention from the side. The figure which illustrates the modification of a rotation arm fixing tool. The schematic diagram which looked at the silencer of the piano of the state which the rotation arm has fixed from the side. The schematic diagram which looked at the silencer of the piano of the state which the rotation arm rotated from the side. The disassembled perspective view of the support mechanism of a rotating shaft. The top view which shows the outline of the silencer of the piano by background art. The disassembled perspective view of the support mechanism of a rotating shaft. A is a plan view of the bush in FIG. 1, B is an α-α cross-sectional view thereof, and C is a bottom view thereof. A is a plan view of a bush in the case of two parts, B is a β-β cross-sectional view thereof, and C is an α-α cross-sectional view thereof. A is a plan view of the first modification of the bush, B is a plan view of the second modification of the bush, and C is a plan view of the third modification of the bush. The disassembled perspective view of the support structure of the rotation support shaft in one Example of the silencer of a piano. A is a cross-sectional view for explaining a main structure of one embodiment of a piano silencer, B is a cross-sectional view of the first modification, C is a cross-sectional view of the second modification, and D is a third modification. Sectional drawing. A is a bottom view of the taper bush, B is a bb cross-sectional view thereof, and C is a plan view thereof.

Explanation of symbols

10 string, 11 hammer shank, 12 rotating shaft, 13 silencer bar, 14 hammer, 23 arm, 231 rotating arm, 232 rotating arm fixture, 25 hammer rail, 40 spacer

Claims (4)

A pivot shaft disposed between the string and the hammer shank;
A hammer projecting in one direction from the peripheral surface of the pivot shaft and colliding with the hammer shank before hitting the string at the first pivot position of the pivot shaft before hitting the string. A silencer bar that prevents the hammer from striking the string and does not prevent the hammer from striking the string at the second rotational position of the pivot shaft;
An arm that supports the pivot shaft;
A piano silencer comprising:
If there is the pivot shaft in the first rotational position, and the rotary shaft so as to collide with the mute bar is arranged at a position close to the hammer as the hammer shank disposed on treble side ,
The arm comprises a rotating arm that supports the rotating shaft and is rotatable when the piano silencer is attached, and a rotating arm fixture that fixes the rotating arm.
Each rotating arm fixture of the plurality of arms is attached to a hammer rail that rotatably supports the hammer shank, arranged in the extending direction.
This is a piano silencer. In the piano silencer according to claim 1 ,
More rotating arm fastener attached to a high sound part side, by being mounted on the hammer rail through a thick spacer, said rotary shaft is inclined with respect to the extending direction of the hammer rest rail, the mute bars Close to the hammer,
This is a piano silencer.   A pivot shaft disposed between the string and the hammer shank;
  A hammer projecting in one direction from the peripheral surface of the pivot shaft and colliding with the hammer shank before hitting the string at the first pivot position of the pivot shaft before hitting the string. A silencer bar that prevents the hammer from striking the string and does not prevent the hammer from striking the string at the second rotational position of the pivot shaft;
  An arm that supports the pivot shaft;
  A piano silencer comprising:
  When the pivot shaft is located at the first pivot position, the pivot shaft is placed on the hammer shank so that the hammer shank disposed on the treble portion side collides with the silencer bar at a position closer to the hammer. Is tilted with respect to the extending direction of the hammer rail that supports the
  The piano is a grand piano.
  This is a piano silencer. A piano with a silencer, comprising the piano silencer according to any one of claims 1 to 3 .

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