JP4851033B2 - Grand piano action mechanism - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a grand piano action mechanism.
[0002]
[Prior art]
Conventionally, as shown in FIG. 7, the action mechanism 100 of the grand piano includes a key 111 that swings according to a player's operation, a capstan screw 112 that rises when the key 111 is pressed, and a whippen flange 113. A whippen 115 that is pivotally supported by the whippen rail 114 and pivots upward when the capstan screw 112 is raised, and is pivotally supported by the tip of the column 115a on the whippen 115 by the rise of the whippen 115. A jack 118 that is pivotally connected to the repetition lever 116 and the tip of the whippen 115 and rises together with the whippen 115 until it contacts the regulating button 117, and a jack that penetrates the long hole 116 a at the tip of the repetition lever 116. It is supported in contact with the tip of 118 A shank roller 119 that separates when pushed up by the jack 118, a hammer shank 122 that is rotatably supported by the shank rail 121 via the shank flange 120, and that rotates upward when the shank roller 119 is pushed up, and a hammer shank 122. And a hammer 123 that moves upward by the rotation of the hammer shank 122 and hits the string 125.
[0003]
That is, in this action operation, the up and down movement accompanying the rotation of the jack 118 is converted into the rotation movement of the hammer shank 122 via the shank roller 119. At that time, in order to efficiently transmit the pressing force of the jack 118 to the hammer shank 122, the support position of the jack 118 (the end face of the core plate 119a of the shank roller 119 is positioned on the end face (dashed line L) of the jack 118). The angle with respect to the whippen 115 is adjusted.
[0004]
This position adjustment is performed by a position adjustment mechanism including an adjustment member 130 provided near the center in the axial direction of the main body of the jack 118 and a spoon 140 erected near the jack 118 of the whippen 115. The adjustment member 130 includes a jack screw 131 screwed and fixed to the jack 118 so as to be able to advance and retreat, a jack button 132 provided at the tip of the jack screw 131, and a shock absorber provided on the tip surface of the jack button 132. It consists of a jack button felt 133.
[0005]
Then, as shown in the figure, the position (angle) of the jack 118 with respect to the whippen 115 is determined by the tip of the adjustment member 130 (that is, the jack button felt 133) being locked to the tip of the spoon 140. The position of the jack 118 can be finely adjusted by moving the jack screw 131 forward and backward with respect to the jack 118 using a predetermined tool (such as a female minus driver).
[0006]
[Problems to be solved by the invention]
By the way, as described above, when the jack 118 comes into contact with the regulating button 117, the shank roller 119 is separated from the jack 118, and the hammer shank 122 is rotated further upward to reach the string by the hammer 123.
[0007]
In the meantime, the adjusting member 130 is separated from the spoon 140, and the jack 118 is further rotated in the clockwise direction in the drawing due to inertia. Thereafter, the jack 118 abuts against the tip wall in the long hole 116a of the repetition lever, and is inverted. Rotate clockwise. Then, the adjustment member 130 is locked to the spoon 140 and returns to the original position, and the shank roller 119 that has returned after finishing the stringing is supported again. Accordingly, the jack 118 must return to the original position before the shank roller 119 returns after finishing striking.
[0008]
However, the jack screw 131 described above is generally made of a metal material to maintain strength, and the jack button 132 is made of plastic or wood. Therefore, the weight of the adjusting member 130 as a whole is increased, and the specific gravity of the jack 118 is increased. ing. For this reason, the inertia weight of the jack 118 is large, and there is a certain limit in shortening the time required to return to the original position after stringing. For this reason, the conventional action mechanism 100 has a certain limit especially in the performance of repeated hits, and has not been able to fully satisfy the demand for high-speed hits by performers having advanced performance techniques.
[0009]
The present invention has been made in view of these problems, and an object of the present invention is to reduce the inertia weight of a jack in a grand piano so as to improve the rotation speed of the jack and improve the repeated performance of the grand piano.
[0010]
[Means for Solving the Problems]
In view of the above problems, the action mechanism of the grand piano according to claim 1 is a wippen that rotates up and down according to the movement of the key, and is supported so as to be rotatable with respect to the wippen, and has a long body. A jack that supports the string-striking member at one end thereof, pushes up the string-striking member based on the key depression, and then returns to the support position of the string-striking member by performing a predetermined reciprocating rotation, and a position of the jack with respect to the wippen And a position adjusting mechanism for holding the jack in the support position.
[0011]
The position adjusting mechanism includes a support member provided on the whippen, a locking member provided at a tip of the support member, which contacts the jack and locks the jack, and the locking member is attached to the jack. Positioning means for advancing and retreating and defining a contact position of the locking member to the jack is configured.
[0012]
According to this configuration, the adjustment mechanism for adjusting the support position of the jack is provided on the whippen side. That is, the adjustment member conventionally provided in the jack is removed, and it is integrated on the whippen side.
For this reason, the weight of the jack is significantly reduced, and the inertia weight can be greatly reduced. As a result, the rotational movement of the jack becomes high speed, and it is possible to sufficiently cope with high-speed repeated hits. Therefore, it is possible to sufficiently satisfy the demands of performers having advanced techniques.
[0013]
As this positioning means, for example, as described in claim 2, it is conceivable to move the locking member forward and backward with respect to the jack by displacing the locking member at the tip of the support member.
Specifically, for example, a plurality of locking protrusions that can be elastically deformed are provided in a stepwise manner at the tip of the support member, while locking grooves that can be engaged with the respective locking portions are provided on the locking member side, A mechanism that performs stepwise position adjustment of the locking member with respect to the support member by applying a pressing force or tensile force from the front to the locking member may be used.
[0014]
However, in this mechanism, since the support member is advanced and retracted in stages, the position of the jack can be adjusted only in stages. For this reason, a problem may arise when the action mechanism requires high-precision position accuracy.
Therefore, as described in claim 3, the positioning means adjusts the screwing length between the screw portion formed at the distal end portion of the support member and the screw hole provided in the locking member, A mechanism for displacing the locking member relative to the support member may be used.
[0015]
According to such a configuration, the position with respect to the support member can be continuously changed and fixed at an arbitrary position by the operation of turning the locking member. For this reason, the jack position can be adjusted with high accuracy.
In addition, since the jacks of the action mechanism are generally arranged side by side in a continuous manner, the gap between adjacent jacks is small. For this reason, in this case, there is a problem that it is difficult to turn the locking member located behind the jack from the front of the grand piano.
[0016]
Therefore, as described in claim 4, a fitting groove for fitting a tip of a predetermined tool (driver or the like) is formed on the jack-side end surface of the locking member, while the fitting groove of the jack is formed. It is preferable that an insertion hole larger than the fitting groove is formed at a position corresponding to.
[0017]
According to such a configuration, since the tip of the tool can be fitted into the fitting groove from the front of the jack through the insertion hole, the operation of turning the locking member using the tool is easily performed. Because it can.
However, generally, it is not easy in the process to provide a hole in a jack having a special shape, and a relatively advanced technique is required to make a hole in a main body of a jack having a small width.
[0018]
Therefore, as described in claim 5, at least a part of the locking member may have a polygonal outer peripheral surface that can be gripped and rotated by a predetermined tool.
In this case, for example, a special tool such as a spanner whose tip is bent at a right angle is inserted into the gap between adjacent jacks, the tip is fitted to the outer periphery of the locking member, and the locking member is rotated. .
[0019]
However, in this case, since it is necessary to prepare a special tool for position adjustment, there is a problem that it is necessary to make a special order or manufacture the tool, which is troublesome.
Therefore, for example, as described in claim 6, it is conceivable that the positioning means is configured as a mechanism for moving the locking member forward and backward with respect to the jack by displacing the support member with respect to the whippen.
[0020]
Specifically, as described in claim 7, for example, a first penetrating hole is formed by drilling a whippen in the vertical direction, and further, the second penetrating the jack and penetrating the first penetrating hole. An insertion hole is formed. Then, the positioning means is engaged with the rack portion formed at the end opposite to the locking member of the support member inserted through the first insertion hole and the second insertion hole and intersecting the rack portion. It is conceivable that the adjustment screw has an adjusting screw having a screw portion.
[0021]
In general, since the jack is supported at a predetermined angle deviated from 90 degrees with respect to the whippen, according to the above configuration, the support member is moved up and down by turning the adjustment screw from the front of the jack. The position of the jack can be adjusted by moving the member forward and backward with respect to the jack.
[0022]
In addition, a buffer member is generally provided at the tip of the locking member, but when the width of the jack body is smaller than the contact surface of the buffer member, the jack is formed on the buffer member due to repeated pressure during contact. Will be attached. When the position is adjusted by displacing the locking member from this state, the contact position of the buffer member with the jack is shifted, so that the adjustment position may be slightly shifted each time adjustment is performed.
[0023]
Therefore, as described in claim 8, the contact surface of the jack with the locking member may be formed larger than the contact surface of the locking member.
According to such a configuration, the abutting portion of the jack always abuts on the entire abutting surface of the buffer member. For this reason, even if the locking member is displaced for position adjustment, the same contact state can be maintained, and the adjustment position does not shift. As a result, the position adjustment can be maintained with high accuracy.
[0024]
Further, the position adjusting mechanism may be provided anywhere as long as it can support the jack on the whippen, but as described in claim 9, a support portion extending from the whippen toward the tail portion of the jack is provided. A position adjustment mechanism may be disposed at the tip of the support portion.
[0025]
In this case, the jack position can be adjusted by locking the tail portion of the jack by the position adjusting mechanism.
However, if the position adjustment mechanism is provided on the tail part side of the jack, the position adjustment mechanism is concentrated at a position far from the rotation axis of the whippen, and the inertial force of the whippen increases. May decrease. For this reason, it is considered that it is the simplest and most effective to provide the position adjusting mechanism on the body of the wippen and to lock the body portion of the jack.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing the configuration of the action mechanism of the grand piano according to the present embodiment.
As shown in FIG. 1, the action mechanism 1 of this embodiment includes a whippen rail via a key 11 that swings according to a player's operation, a capstan screw 12 that rises when the key 11 is pressed, and a whippen flange 13. 14 is pivotally supported by the capstan screw 12 and is pivotally supported by the pivot shaft 15b at the tip of the column 15a on the whippen 15 as the whippen 15 is lifted. The repetition lever 16 and the pivot shaft 15c at the tip of the whippen 15 are pivotally connected, and the jack 18 ascends with the whippen 15 until it comes into contact with the regulating button 17, and the jack 18 is pushed up and hit by the key 18 based on the key depression. It is composed of a string striking member and the like. The string-striking member is supported by being in contact with the tip of the jack 18 passing through the long hole 16a at the tip of the repetition lever 16 and separated when the jack 18 is pushed up. The shank roller 19 and the shank flange 20 are separated. The hammer shank 22 is rotatably supported by the shank rail 21 and pivots upward when the shank roller 19 is pushed up. The hammer shank 22 is mounted on the tip of the hammer shank 22 and moved upward by the rotation of the hammer shank 22. And a hammer 23 for hitting the string 25.
[0027]
An adjusting member 30 as a position adjusting mechanism for the jack 18 is provided between the whippen 15 and the jack 18. FIG. 2A is a perspective view illustrating a schematic configuration around the adjustment member 30.
That is, the adjustment member 30 is provided in the vicinity of the jack 18 on the whippen 15, and is provided with a stop screw 31 made of a metal rod standing on the jack and extending upward and bent toward the jack 18 at its tip. A stop button 32 made of a resin or wooden cylinder provided at the tip of 31 and a button felt 33 made of cushioning felt provided on the tip of the stop button 32 are configured.
[0028]
In this embodiment, the stop screw 31 corresponds to the support member, and the stop button 32 and the button felt 33 correspond to the locking member.
More specifically, as shown in the enlarged view of FIG. 2B, a screw portion 31a is provided at the tip of the stop screw 31, and the stop button 32 faces the surface facing the stop screw 31. A screw hole 32a that can be screwed into the screw portion 31a is provided. The length of the screw portion 31a and the depth of the screw hole 32a are formed with a margin so that adjustment is possible even at a position deviated to some extent from the average adjustment position. Therefore, the position of the stop button 32 relative to the stop screw 31, that is, the advance / retreat position of the adjustment member 30 relative to the jack 18 is appropriately adjusted by turning the stop button 32 in the direction of the arrow in the drawing and adjusting the screwing length. be able to.
[0029]
Further, a button felt 33 is adhered to the surface of the stop button 32 opposite to the stop screw 31, and a square groove 32b (fitting) for inserting and fitting the tip of the minus driver D at the center thereof. Groove). Further, a circular hole 33a having a diameter larger than that of the square groove 32b is formed in the center of the button felt 33. On the other hand, a circular hole 18b (insertion hole) is formed at a position corresponding to the circular hole 33a of the elongated main body 18a of the jack 18 as shown in FIG.
[0030]
For this reason, when adjusting the position of the adjusting member 30, a flathead screwdriver D is inserted from the front of the action mechanism 1, and the tip of the adjusting member 30 is inserted and fitted into the square groove 32b via the circular holes 18b and 33a. 32 is rotated. Then, the end face of the button felt 33 is brought into contact with the main body of the jack 18 so that the end face of the core plate 19a of the shank roller 19 is placed on the end face of the jack 18 as described above.
[0031]
Returning to FIG. 1, in the action mechanism 1 adjusted in this way, the shank roller 19 is separated from the jack 18 and the hammer shank 22 is moved upward at the timing when the jack 18 contacts the regulating button 17 after the key is pressed. It turns and reaches the string by the hammer 23. At this time, when the jack 18 is separated from the adjustment member 30, it further rotates clockwise in the figure, but after the key release, it rotates counterclockwise and quickly returns to the original position.
[0032]
As described above, in the action mechanism 1 of the present embodiment, the adjustment member 30 is provided on the side of the whippen 15. That is, the adjustment member conventionally provided in the jack is removed, and it is integrated on the whippen side.
For this reason, the weight of the jack 18 becomes significantly lighter than before, and the inertia weight can be greatly reduced. As a result, the rotational movement of the jack 18 becomes high speed, and can sufficiently cope with high-speed continuous hitting. Therefore, it is possible to sufficiently satisfy the demands of performers having advanced techniques.
[0033]
Further, the jack 18 of the action mechanism 1 is generally arranged continuously for all keys (88 keys), so that the gap is small, and the tool can reach a component behind the jack 18. Although it is difficult, this can be facilitated by devising the structure of the jack 18 and the adjusting member 30 as in this embodiment.
[Second Embodiment]
In the said 1st Example, the aspect which drilled the circular hole 18b in the main body 18a of the jack 18 was shown as a structure for adjusting the position of the adjustment member 30 provided in the whippen 15 side. However, in general, it is not easy in the process to provide a hole in the jack 18 having a special shape, and relatively high technology is required to make a hole in the main body 18a having a small width. Therefore, in this embodiment, a configuration that does not require such a hole in the jack will be described with reference to FIG.
[0034]
However, this configuration is the same as that of the first embodiment except that the jack is not provided with a hole and the adjustment member has a partly different structure. Therefore, the description of the same components is omitted. To do.
As shown in FIG. 3, the adjustment member 230 of the action mechanism of this embodiment is erected in the vicinity of the jack 218 on the whippen 215, and this adjustment member 230 extends upward to the jack 218 side at its tip. A stop screw 231 made of a bent metal rod, a stop button 232 made of a resin or wooden cylinder provided at the tip of the stop screw 231, and a button made of a cushioning felt provided on the tip surface of the stop button 232 It consists of a felt 233.
[0035]
More specifically, as shown in the enlarged view of FIG. 4B, the stop button 232 of this embodiment is connected to a main body 232a formed in a hexagonal column and the main body 232a, and is larger than the main body 232a. It is comprised from the disk-shaped head 232b which has a cross section. The button felt 233 is bonded to the tip surface of the head 232b.
[0036]
A screw hole 232c that can be screwed into a screw portion 231a provided at the tip of the stop screw 231 is provided on the surface of the stop button 232 that faces the stop screw 231. For this reason, a special shape spanner S having a tip portion bent by about 90 degrees as shown in FIG. 6A is inserted from the front of the action mechanism, and the main body 232a is gripped and turned by the tip portion, thereby stopping. The position of the button 232 relative to the stop screw 231, that is, the advance / retreat position of the adjustment member 230 relative to the jack 218 can be adjusted appropriately.
[0037]
As described above, according to the action mechanism of the present embodiment, the position of the adjustment member 230 can be adjusted without making a hole in the jack 218. For this reason, the manufacturing of the action mechanism is simplified as compared with the first embodiment, and the manufacturing cost can be reduced. Further, since the adjusting member 230 is provided on the side of the whippen 215, the same effect as that of the first embodiment can be obtained.
[0038]
In this embodiment, the shape of the main body 232a of the stop button 232 is a hexagonal column, but the shape of the main body 232a may be any shape as long as it has a polygonal outer peripheral surface.
[Third embodiment]
In the second embodiment, it is necessary to prepare a special tool for adjusting the position of the adjusting member 230, so that it is necessary to make a special order or make it.
[0039]
Therefore, in the present embodiment, a configuration that does not need to be drilled on the jack side as in the first embodiment and does not require a special tool as in the second embodiment will be described with reference to FIG.
However, this configuration is the same as the first embodiment except that the jack is not provided with a hole and the adjustment member is partially different in structure. Omitted.
[0040]
As shown in FIG. 4, the adjusting member 330 of this embodiment is erected in the vicinity of the jack 318 on the whippen 315, and the adjusting member 330 extends upward and is bent toward the jack 318 side at its tip. A stop screw 331 made of a rod, a stop button 332 made of a resin or wooden column provided at the tip of the stop screw 331, and a button felt 333 made of a cushioning felt wound around the stop button 332 Has been.
[0041]
Unlike the stop button 32 of the first embodiment and the stop button 232 of the second embodiment, the stop button 332 is in contact with the jack 318 via the button felt 333 on the curved surface portion of the cylindrical body. It has become. For this reason, regardless of the angle of the jack 318, the contact surface can be contacted with substantially uniform pressure.
[0042]
One end of the stop screw 331 passes through the button felt 333 and is assembled to the stop button 332, and the other end slides into an insertion hole 315a (first insertion hole) formed in the wippen 315 in the vertical direction. It is inserted as possible. That is, the other end portion is provided with a rack portion 331a having a plurality of rack teeth continuously arranged in the longitudinal direction as shown in the enlarged view of FIG.
[0043]
On the other hand, the projecting portion 315b provided below the whippen 315 is provided with an insertion hole 315c (second insertion hole) that opens forward and intersects the insertion hole 315a. The insertion hole 315c includes An adjustment screw 351 having a screw portion 351a having a gear-shaped cross section at the tip is inserted. The screw portion 351a and the rack portion 331a are engaged with each other, and by inserting the driver D from the front and turning the adjustment screw, the stop screw 331 can be moved vertically with respect to the wippen 315 so that the position thereof can be adjusted. It has become. In this case, since the jack 318 is inclined at a predetermined angle with respect to the stop screw 331, the position of the jack 318 is changed by moving the stop screw 331 up and down to change the contact position of the adjustment member 330 with the jack 318 up and down. (Angle) can be adjusted.
[0044]
As described above, according to the action mechanism of the present embodiment, the position of the adjustment member 330 can be adjusted without making a hole in the jack 318 and without using a special tool. Further, since the adjustment member 330 is provided on the side of the whippen 315, the same effect as in the first embodiment can be obtained.
[0045]
As mentioned above, although the Example of this invention was described, it cannot be overemphasized that embodiment of this invention can take various forms, as long as it belongs to the technical scope of this invention, without being limited to the said Example at all. Nor.
For example, in the first embodiment and the second embodiment, since the button felt is formed in a disk shape, the button felt is caused by repeated contact pressure when the width of the main body of the jack is smaller than the diameter of the button felt. Will have a jack shape. When the adjustment member is adjusted from this state, the button felt is rotated, so that the shaped portion is rotated and the state of the contact surface is changed. For this reason, the adjustment position may be slightly shifted each time adjustment is performed.
[0046]
Therefore, for example, as shown in FIG. 5A as a modified example, the contact surface of the contact portion 418a of the jack 418 may be formed in a circular shape that is the same as or larger than the contact surface of the button felt 433. Good. According to such a configuration, the contact portion 418a of the jack 418 always contacts the entire contact surface of the button felt 433. For this reason, even if the stop button 432 is rotated for position adjustment, the same contact state can be maintained, and the adjustment position does not shift. As a result, the accuracy of position adjustment increases.
[0047]
FIG. 5A shows a mode in which the circular hole 418a is formed in the jack 418, that is, a modification corresponding to the first embodiment. However, the configuration in which the jack 418 is not drilled as in the second embodiment. But of course it is equally applicable.
Moreover, in the said 1st Example and 2nd Example, it was set as the aspect which adjusts the position with respect to the stop screw of a stop button, ie, the advance / retreat position with respect to the jack of an adjustment member, by screwing a stop button with a stop screw. Other configurations are also possible.
[0048]
For example, as shown in FIG. 5B, the stop screw 531 is formed of plastic or the like, and a plurality of locking projections 531a that can be elastically deformed are provided in a stepwise manner. It is good also as a structure which provided the latching groove | channel 532a which can be engaged with this latching protrusion 531a in steps. In this case, the stop button 532 can be moved forward and backward with respect to the stop screw 531 by pressing the stop button 532 against the stop screw 531 or pulling from the stop screw 531. That is, the advance / retreat position of the adjustment member with respect to the jack can be adjusted stepwise.
[0049]
Furthermore, as shown in FIG. 6, the tail member 618 a of the jack 618 may be locked by the adjustment member 630.
Specifically, in this modification, a support portion 615a is extended from the whippen 615 to the tail portion 618a side, and an adjustment member 630 is provided at the tip of the support portion 615a. The adjustment member 630 has a stop screw 631 supported at one end so as to be able to advance and retreat with respect to the support portion 615a, a stop button 632 provided at the other end (lower end) of the stop screw 631, and a tip surface of the stop button 632 It is comprised from the provided button felt 633 for a buffer.
[0050]
In addition, a rack portion is formed at one end of the stop screw 631, and an adjustment screw 651 that is screwed across the rack portion is inserted into a horizontal insertion hole 615b provided in the support portion 615a. Thus, the same configuration as that of the third embodiment is realized. For this reason, the position of the front end surface of the button felt 633 can be adjusted by inserting the driver from the front and turning the adjusting screw 651, whereby the position of the jack 618 can be adjusted.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view illustrating an action mechanism according to a first embodiment of the present invention.
FIG. 2 is an explanatory diagram showing details of a main part of the action mechanism of the first embodiment.
FIG. 3 is an explanatory diagram showing details of a main part of an action mechanism according to a second embodiment.
FIG. 4 is an explanatory diagram illustrating details of a main part of an action mechanism according to a third embodiment.
FIG. 5 is an explanatory diagram illustrating details of a main part of an action mechanism according to a modification.
FIG. 6 is an explanatory diagram showing details of a main part of an action mechanism according to a modification.
FIG. 7 is a cross-sectional view illustrating a conventional action mechanism.
[Explanation of symbols]
1 ... Action mechanism, 11 ... Key,
15, 215, 315, 615 ... Whippen,
18, 218, 318, 418, 618 ... Jack,
18a ... main body, 22 ... hammer shank,
23 ... hammer, 25 ... string,
30, 230, 330, 630 ... adjustment member,
31, 231, 331, 631 ... stop screw,
32,232,332,432,632 ... stop button,
33,233,333,433,633 ... button felt,
351, 651 ... Adjustment screw, 618a ... Tail

Claims (9)

Whippen that rotates up and down according to the movement of the key,
The chord member is supported by the whippen so as to be pivotable, and the string striking member is supported by one end of the elongated main body. The jack returning to the support position of the stringing member again,
A position adjusting mechanism for holding the jack in the support position by adjusting the position of the jack relative to the whippen;
In the action mechanism of a grand piano equipped with
The position adjustment mechanism is
A support member provided on the whippen;
A locking member that is provided at a tip of the support member and contacts the jack to lock the jack;
Positioning means for advancing and retracting the locking member with respect to the jack, and defining a contact position of the locking member to the jack;
An action mechanism of a grand piano characterized by comprising 2. The positioning means moves the locking member forward and backward with respect to the jack by displacing the locking member with respect to the support member at a distal end portion of the support member. The action mechanism of the described grand piano. The positioning means adjusts a screwing length between a screw portion formed at a distal end portion of the support member and a screw hole provided in the lock member, so that the lock member is attached to the support member. 3. The action mechanism for a grand piano according to claim 2, wherein the action mechanism is displaced. While the end surface on the jack side of the locking member is formed with a fitting groove for fitting a tip of a predetermined tool,
An insertion hole is formed at a position corresponding to the fitting groove of the jack,
The action mechanism of the grand piano according to claim 3, wherein a tip of the predetermined tool can be fitted into the fitting groove from the front of the jack through the insertion hole. 3. The action mechanism for a grand piano according to claim 2, wherein at least a part of the locking member has a polygonal outer peripheral surface that can be gripped and rotated by a predetermined tool. 2. The action mechanism of a grand piano according to claim 1, wherein the positioning means moves the locking member forward and backward with respect to the jack by displacing the support member with respect to the whippen. In the action mechanism of the grand piano according to claim 6,
A first insertion hole formed by drilling the whippen vertically;
A second insertion hole that intersects the first insertion hole and is open to the jack side;
With
The positioning means includes
A rack portion formed at an end of the support member that is inserted through the first insertion hole on the side opposite to the locking member;
An adjustment screw having a screw part that is inserted through the second insertion hole and meshes with the rack part;
Consisting of
An action mechanism of a grand piano, wherein the support member is moved up and down by turning the adjustment screw from the front of the jack. 8. The action mechanism for a grand piano according to claim 1, wherein a contact surface of the jack with the locking member is formed larger than a contact surface of the locking member. Providing a support portion extending from the whippen to the tail portion of the jack, and arranging the position adjusting mechanism at the tip of the support portion;
The grand piano action mechanism according to any one of claims 1 to 8, wherein the tail portion can be locked by the position adjusting mechanism.

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