Upright piano action

Abstract

To provide an upright piano action which improves rapid striking at a shallow key pressing position.SOLUTION: An action 1 comprises: a jack 7 provided on a wippen 6 which rotates upward in response to pressing a key 4, and which rotates between an engagement position where a hammer thrust portion 7b engages with a hammer 3 and a disengagement position where the hammer thrust portion disengages from the hammer; a return spring 15 for the jack; a regulating button 16 for rotating the jack toward the disengagement position when the key is pressed; and a cushion 22 attached to a regulating rail 18. The cushion has compressibility such that the hammer thrust portion comes into contact with the cushion just before the hammer thrust portion disengages from the hammer, and prevents the hammer thrust portion from disengaging from the hammer when the key is shallowly pressed with a predetermined key pressing amount or less, while allowing the hammer thrust portion to disengage from the hammer when the key is normally pressed with the maximum keystrokes.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an action of an upright piano that operates in response to depression of a key to rotate a hammer and strike a string. [Background technology]

[0002] As an example of a conventional upright piano action, the one disclosed in Patent Document 1 is known. This action is provided above the rear end of the keyboard and includes a wippen placed on the rear end of each key, a jack rotatably attached to the wippen, a jack spring provided between the wippen and the jack, and a regulating button fixed to the regulating rail. The jack is formed in an L-shape from a base and a hammer thrust part extending upward at a substantially right angle from the rear end of the base. In the key-released state, the tip of the hammer thrust part abuts against the butt of the hammer, and the base part faces the regulating button from below. In addition, a spring part is integrally provided on the front surface of the hammer thrust part of the jack, and in the key-released state, the spring part faces the regulating rail from behind.

[0003] In this configuration, when the key is pressed, the wippen is pushed up by the rear end of the key and rotates upward together with the jack. As a result, the hammer is pushed up by the jack and rotates toward the vertically stretched rear string. Then, the jack rotates relative to the wippen against the spring force of the jack spring as its base engages with the regulating button, and is released from the hammer. The hammer then rotates in a free state and strikes the string. Meanwhile, when the jack is released from the hammer, the spring portion comes into contact with the regulating rail from the rear, and the spring force of the spring portion acts on the jack due to the reaction force from the regulating rail. Then, when the key is released thereafter, as the wippen and the jack rotate in the direction opposite to when the key was pressed, the jack quickly returns to its original position relative to the wippen due to the spring force of the jack spring and the spring portion, and engages with the hammer. This allows the wippen to push up the hammer when the key is pressed again. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2006-91516 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, the above-mentioned conventional action has the following problems. That is, assuming that the same key is repeatedly struck in a shallow key pressing range, such as when performing a trill (hereinafter, such a case will be referred to as "repeated striking at a shallow key pressing position"), in order for the hammer to strike the string, it is necessary that the jack has already returned to the engagement position with the butt of the hammer at the timing when the key is struck again. However, in the conventional action, the spring part of the jack abuts against the regulating rail after the jack is released from the butt, and acts to return the jack. For this reason, it takes time for the jack to return to the engagement position with the butt, and while the butt returns first, the tip of the jack cannot return to the engagement position with the butt completely. Therefore, even if a key is struck in this state, the bat cannot be thrust up, and a key cannot be struck.

[0006] The present invention has been made to solve the above-mentioned problems, and has as its object to provide an action for an upright piano that can improve the ability to strike keys repeatedly at shallow key depression positions. [Means for solving the problem]

[0007] In order to achieve the above object, the invention according to claim 1 is an action for an upright piano that operates in response to the depression of a key, rotating a hammer and striking a string, the action comprising: a wippen that rotates upward in response to the depression of a key; a jack having a base and a hammer thrust portion extending vertically, which is rotatably mounted on the wippen and rotates between an engagement position where the hammer thrust portion engages with the hammer and a disengagement position where the hammer thrust portion is disengaged from the hammer; a support member that is mounted on the side that the hammer thrust portion approaches when the jack rotates toward the disengagement position when a key is pressed and faces the hammer thrust portion; a return spring that is mounted between the wippen and the base of the jack for returning the jack to the engagement position; The key includes a regulating button which, when pressed, causes the base of the jack to come into contact with the regulating button, thereby rotating the jack towards a release position and releasing it from the hammer, and a cushion attached to the side of the support member facing the hammer thrust portion of the jack. The cushion is positioned so that the hammer thrust portion comes into contact with the cushion just before it releases from the hammer, and has compressibility such that, when the key is pressed shallowly, that is, when the key is pressed less than a predetermined amount, the hammer thrust portion in contact with the cushion is prevented from releasing from the hammer, but, when the key is pressed normally, that is, when the key is pressed to the maximum extent, the hammer thrust portion in contact with the cushion is allowed to release from the hammer.

[0008] According to the action of this upright piano, in the key-released state, the jack is located at the engagement position and the hammer thrust portion is engaged with the hammer. When a key is pressed from this state, the wippen moves in conjunction with the key and rotates upward together with the jack that is rotatably mounted on the wippen. As a result, the hammer is thrust up by the hammer thrust portion of the jack and rotates. During this upward rotation of the wippen and jack, the base of the jack comes into contact with the regulating button, causing the jack to rotate toward the release position.

[0009] During the rotation of the jack toward the release position, the hammer thrust portion comes into contact with the cushion attached to the support member just before it is released from the hammer. In this case, the cushion has the above-mentioned compressibility, and prevents the abutting hammer thrust portion from coming off the hammer when the key is pressed shallowly, that is, when the key is pressed less than a predetermined amount. This maintains the engagement state of the hammer and the jack. Therefore, when the key is pressed again from this state (when the key is pressed repeatedly from a shallow key pressing position), the hammer thrust portion of the jack can instantly thrust up the hammer to rotate and strike the string, thereby improving the ability to repeatedly press the key at a shallow key pressing position.

[0010] On the other hand, during normal keystrokes, when the key is depressed to its maximum (full) height, the cushion allows the abutting hammer lifting portion to separate from the hammer due to the compressibility described above. As a result, just like in normal keystrokes, the jack separates from the hammer, allowing the hammer to rotate freely and strike the string.

[0011] When the key is then released, both the wippen and the jack rotate downward. The jack, which had rotated to the release position, returns to the engagement position due to the spring force of the return spring and the restoring force of the cushion, making it possible for the hammer to be thrust up by the hammer thrust section. Unlike a conventional action in which the spring forces of the spring section and the jack spring act simultaneously, this action only requires the spring force of the return spring and the restoring force of the cushion to act, so the key load curve does not rise sharply, and the player's fingertips do not feel a strong "springiness," and the player can obtain the same touch as a normal upright piano.

[0012] The invention according to claim 2 is characterized in that in the action of the upright piano according to claim 1, the cushion is made of urethane foam.

[0013] Since urethane foam has a cell structure due to foaming, by using it as a cushion material, it is possible to easily achieve the relatively soft compressibility required for the cushion of claim 1, and unlike spring materials such as return springs, it is possible to avoid the occurrence of a springy feeling. Furthermore, among urethane foams, those called high-performance urethane foams, which have an extremely fine and uniform cell structure, have small residual compression set and are almost free of the "sagging" seen in other foams, ensuring the dimensional stability and durability of the cushion.

[0014] The invention according to claim 3 is characterized in that, in the action of the upright piano described in claim 1, the action is a drop action in which at least a portion is located below the key and the wippen is pulled up by a pressed key and rotated upward, thereby operating.

[0015] In this configuration, the action is a drop action, at least a part of which is located below the key, and the wippen is pulled up by the depressed key and rotated upward to activate the action. Therefore, in this case as well, the above-mentioned effect of the invention of claim 1 can be obtained in the same way. [Brief description of the drawings]

[0016] [Figure 1] 1 is a side view showing the action of an upright piano according to an embodiment of the present invention, together with the keys and strings. [Diagram 2] FIG. 2 is a partial side view showing the action of FIG. 1 in a key-released state. [Diagram 3] FIG. 2 is a partial side view showing the action of FIG. 1 just before the jack separates from the butt of the hammer when the key is pressed. [Figure 4] FIG. 2 is a partial side view showing the action of FIG. 1 in a state where the hammer has returned after being rotated in reaction to the key being fully depressed. [Diagram 5] FIG. 2 is a side view similar to FIG. 1, showing an example of a piano in which the action of FIG. 1 is used as a drop action. [Figure 6] FIG. 3 is a partial side view similar to FIG. 2, showing an example in which a cushion is arranged on a jack stop rail provided separately from the regulating rail. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] A preferred embodiment of the present invention will be described in detail below with reference to the drawings. Fig. 1 shows an action 1, a keyboard 2, and a hammer 3 of an upright piano according to an embodiment of the present invention in a key-released state. In the following description, the front side of the upright piano as viewed from the player's side (the right side in Fig. 1) is referred to as the "front," and the back side (the left side in Fig. 1) is referred to as the "rear."

[0018] The keyboard 2 is made up of many keys (white and black keys) 4 (only one is shown) lined up in the left-right direction of the upright piano (depth direction in FIG. 1). Each key 4 extends in the front-rear direction (left-right direction in FIG. 1) and is supported in its center so as to be freely rotatable around a balance pin 5a erected on a reed 5.

[0019] The action 1 is attached to action brackets (not shown) provided on the left and right ends of the reed 5 above the rear end of the keyboard 2, and is provided so as to extend between the two brackets. The action 1 has a wippen 6, a jack 7, etc., and these components are provided for each key 4 (only one of each is shown). A center rail 11 and a hammer rail 12 are stretched between the left and right action brackets. A wippen flange 6a, a butt flange 25a, and a damper flange 31a are screwed to the center rail 11 for each key 4.

[0020] The wippen 6 is made of, for example, a molded product of synthetic resin containing carbon fiber, extends in the front-rear direction, has its rear end rotatably attached to a wippen flange 6a, and its front end is placed on a capstan button 4a provided at the rear end of the top surface of the key 4. A backcheck wire 13a is erected at the front end of the top surface of the wippen 6, and a backcheck 13 is attached to its upper end. In addition, a spoon 14 for driving a damper 31, which will be described later, is erected at the rear end of the top surface of the wippen 6.

[0021] The jack 7 is made of, for example, a molded product of a synthetic resin containing carbon fiber, and is formed in an L-shape with a base 7a that extends slightly in the front-rear direction and a hammer thrust portion 7b that extends upward from the rear end of the base 7a. The jack 7 is rotatably attached to the corner between the base 7a and the hammer thrust portion 7b near the center of the wippen 6. A jack spring 15 is attached between the base 7a of the jack 7 and the wippen 6. The jack spring 15 is made of a coil spring, and biases the jack 7 that rotates when a key is pressed, to return it to its original position.

[0022] A regulating button 16 is provided above the base 7a of the jack 7. The regulating button 16 is provided for each key 4 via a plurality of regulating brackets 17 (only one is shown) provided on the center rail 11 and a regulating rail 18 attached to the front end of the bracket and extending in the left-right direction. Felt 21 and a cushion 22 according to the present invention are attached in this order to the back of the regulating rail 18. The felt 21 is made of the same material as the ordinary felt attached to the back of the regulating rail, for example, and has a predetermined thickness and softness in the front-rear direction, reducing noise when a key is pressed and functioning as a spacer to position the cushion 22.

[0023] 3, the cushion 22 is disposed so that the hammer thrust portion 7b of the jack 7 comes into contact with the cushion 22 from behind just before it separates from the butt 25 of the hammer 3. The cushion 22 has a relatively soft compressibility such that the hammer thrust portion 7b, in contact with the cushion 22, is prevented from separating from the butt 25 during shallow keystrokes in which the key 4 is depressed by less than a predetermined amount, whereas the cushion 22 allows the hammer thrust portion 7b, in contact with the cushion 22, to separate from the butt 25 during normal keystrokes in which the key is depressed to the maximum extent.

[0024] The cushion 22 is made of, for example, urethane foam. Since urethane foam has a cell structure due to foaming, it easily realizes the relatively soft compressibility required for the cushion 22, and has the advantage of not producing a springy feeling, unlike spring materials such as the jack spring 15. Furthermore, among urethane foams, those called high-performance urethane foams, which have a very fine and uniform cell structure, such as urethane foams sold commercially under the registered trademark "PORON," have particularly small residual compression strain and are almost free of the "sagging" seen in other foams, thereby ensuring the dimensional stability and durability of the cushion 22.

[0025] The hammer 3 has a butt 25, a hammer shank 26, and a hammer head 27. The butt 25 is rotatably attached at its lower end to the butt flange 25a described above. The hammer shank 26 stands on the upper surface of the butt 25, and the hammer head 27 is attached to its upper end. In the released key state shown in Fig. 1, the hammer shank 26 abuts against the hammer rail 12 from behind, and the hammer head 27 faces the vertically stretched rear string S.

[0026] A catcher 28 is provided on the front side of the butt 25. The catcher 28 is located behind and faces the back check 13. A butt spring 29 is provided on the butt 25, and the butt 25 is biased in the clockwise direction in FIG. 1 by the butt spring 29. In addition, in the key-released state, the hammer thrust portion 7b of the jack 7 engages with the butt 25 from below. The position of the jack 7 at this time is the engaged position.

[0027] A damper 31 is provided for each key 4 behind the action 1. The damper 31 is rotatably attached to the damper flange 31a described above and is composed of a damper lever 31b extending vertically, a damper head 31d attached to the upper end of the damper 31b via a damper wire 31c, and a damper spring 31e that biases the damper lever 31b toward the string S. The spoon 14 described above faces the lower end of the damper lever 31b from the front.

[0028] With the above configuration, when a key is pressed, as the whippen 6 rotates, the spoon 14 presses the lower end of the damper lever 31b, moving the damper head 31d away from the string S and allowing the string S to vibrate when struck by the hammer head 27. When the key is released, the damper head 31d comes into contact with the vibrating string S due to the biasing force of the damper spring 31e, thereby stopping the sound.

[0029] Next, the operation of the action 1 and hammer 3 of the upright piano configured as described above from the start to the end of key pressing will be described with reference to Figures 1 to 4. First, as shown in Figures 1 and 2, in the key-released state, the jack 7 is in the engagement position, the upper end of the hammer thrust portion 7b engages with the butt 25 of the hammer 3, the front surface faces the cushion 22 with a gap between them, and the base 7a faces the regulating button 16a from below. Also, the hammer shank 26 of the hammer 3 rests against the hammer rail 12, and the hammer head 27 is spaced from the string S.

[0030] When the key 4 is pressed in this key-released state, the wippen 6 is pushed up by the key 4, and the jack 7 rotates upward together with the wippen 6. As a result, the hammer 3 is pushed up by the hammer pushing-up portion 7b of the jack 7 and rotates backward. During this upward rotation of the wippen 6 and the jack 7, the base portion 7a of the jack 7 comes into contact with the regulating button 16, causing the jack 7 to rotate toward the release position (clockwise in FIG. 2).

[0031] During the rotation of the jack 7 toward the release position, as shown in Fig. 3, the hammer thrust portion 7b comes into contact with the cushion 22 just before it leaves the butt 25 of the hammer 3. In this case, the cushion 22 has the compressibility described above, and prevents the abutting hammer thrust portion 7b from leaving the butt 25 of the hammer 3 when the key 4 is shallowly pressed with less than a predetermined key depression amount. This maintains the engagement state of the jack 7 with the butt 25. Therefore, when the key 4 is pressed again from this state (when repeated key strokes are made from a shallow key depression position), the hammer thrust portion 7b immediately thrusts up the butt 25, allowing the hammer 3 to rotate and strike the string, thereby improving the ability to make repeated key strokes at a shallow key depression position.

[0032] On the other hand, during normal keystrokes in which the key 4 is depressed to its maximum (full) height from the normal keystroke height, the cushion 22 allows the abutting hammer thrust portion 7b to separate from the butt 25 of the hammer 3 due to its compressibility as described above. As a result, as in normal keystrokes, the jack 7 separates from the hammer 3, causing the hammer 3 to rotate backward in a free state and strike the string. In this case, when the key 4 is fully depressed, the hammer 3, which rotates forward in recoil after striking the string, is stopped by the catcher 28 engaging with the back check 13, as shown in FIG.

[0033] Thereafter, when the key 4 is released, both the wippen 6 and the jack 7 rotate downward. The jack 7, which had rotated to the release position, returns to the engagement position with the butt 25 due to the spring force of the jack spring 15 and the restoring force of the cushion 22, making it possible for the hammer thrust-up portion 7b to thrust up the butt 25. Unlike a conventional action in which the spring forces of the spring portion and the jack spring act simultaneously, this action only involves the spring force of the jack spring 15 and the restoring force of the cushion 22, so that the key load curve does not rise sharply, and the player's fingertips do not feel a strong "springiness," and the player can obtain the same touch as a normal upright piano.

[0034] In addition, by using urethane foam as the material for cushion 22, it is possible to easily achieve the relatively soft compressibility required for cushion 22, thereby preventing the occurrence of a springy feeling and ensuring the dimensional stability and durability of cushion 22.

[0035] 5 shows an example in which the action 1 of the present invention is used as a drop action in a piano 51. The structure and operation of this piano 51 will be briefly described below.

[0036] The piano 51 includes a keyboard device 52, an action 1 as a drop action arranged below the keyboard device 52, hammers 3, and strings S. The keyboard device 52 has a number of first keys 52A (white keys and black keys, only one of each is shown) arranged in the left-right direction, and a number of second keys 52B (only one is shown) arranged in the left-right direction below each of the first keys 52A. The first keys 52A are rotatably supported at their rear ends by a balance pin 53, and the second keys 52B are rotatably supported near their centers by a fulcrum 54, and an actuator pin 55 provided on the corresponding first key 52A abuts against their front ends from above.

[0037] An adjustment screw 56 is screwed into the rear end of the upper surface of the second key 52B, and a guide hole 57 is formed behind the adjustment screw 56, penetrating it in the vertical direction. A wire 58 having appropriate flexibility and strength is wound around the adjustment screw 56, and the wire 58 passes through the guide hole 57 and extends downward.

[0038] 1, and is disposed rearward and below the first key 52A and the second key 52B. A mounting screw 59 is screwed into the front surface of the wippen 6, and the lower end of the wire 58 is engaged with and attached to a ring portion 59a at the front end of the mounting screw 59. The tension of the wire 58 is adjusted by changing the amount of winding of the wire 58 with an adjustment screw 56.

[0039] In the above configuration, when the first key 52A is pressed from the key-released state shown in Fig. 5, it rotates downward around the balance pin 53 and presses down the front end of the second key 52B via the actuator pin 55. As a result, the second key 52B rotates clockwise around the fulcrum 54, and its rear end pulls up the wippen 6 via the wire 58, rotating it upward, thereby operating the action 1 in the same way as in Fig. 1. Therefore, even when the action 1 is used as a drop action as in this example, the same effect as described above with the action 1 in Fig. 1 can be obtained.

[0040] The present invention is not limited to the embodiment described above, and can be embodied in various forms. For example, in the embodiment, the felt 21 and the cushion 22 are attached in that order to the back surface of the regulating rail 18, but the felt 21 may be omitted and only the cushion 22 may be attached.

[0041] In the embodiment, the cushion 22 is placed on the regulating rail 18 that is also used as the jack stop rail, but if both rails are provided separately, the cushion may be placed on the jack stop rail. Fig. 6 shows one example. In this example, a jack stop rail 62 is placed between multiple jack brackets 61 (only one is shown) provided on the center rail 11, separate from the regulating rail 18 to which the regulating button 16 is attached. Then, felt 21 and cushion 22 are affixed, in that order, to the back surface of the jack stop rail 62.

[0042] Furthermore, in the embodiment, urethane foam is used as the material of the cushion 22, but other materials, such as foamed resin other than urethane foam or soft synthetic resin, can be used as long as they meet the conditions of the present invention. Also, the detailed configuration of the action 1 shown in the embodiment is merely an example and can be appropriately changed within the scope of the spirit of the present invention. [Explanation of symbols]

[0043] 1 Action 3. Hammer 4 keys 6 Wippen 7. Jack 7a Base 7b Hammer thrust section 15 Jack spring (return spring) 16 Regulating Button 18 Regulating rail (support member) 22 Cushion 25 Hammer Bat 52A 1st key (key) 52B Second Key (Key) S string

Claims

1. An upright piano action that operates when a key is pressed to rotate a hammer and strike a string, A wippen that rotates upward in response to key depression; a jack having a base and a hammer thrust portion extending in a vertical direction, the jack being rotatably attached to the wippen and rotatable between an engagement position where the hammer thrust portion engages with the hammer and a disengagement position where the hammer thrust portion is disengaged from the hammer; a support member provided on a side to which the hammer thrust portion approaches when the jack rotates toward the release position when a key is pressed, the support member facing the hammer thrust portion; a return spring provided between the wippen and the base of the jack for returning the jack to the engagement position; a regulating button that, when a key is pressed, comes into contact with the base of the jack, thereby rotating the jack toward the release position and releasing the jack from the hammer; a cushion attached to the support member on a side facing the hammer lifting portion of the jack, said cushion is positioned so that the hammer thrust portion comes into contact with the cushion just before it separates from the hammer, and has compressibility such that, during a shallow keystroke in which the key is depressed by less than a predetermined amount, the hammer thrust portion in contact with the cushion is prevented from separating from the hammer, while, during a normal keystroke in which the key is depressed to the maximum extent, the hammer thrust portion in contact with the cushion is allowed to separate from the hammer.

2. 2. The action of an upright piano according to claim 1, wherein the cushion is made of urethane foam.

3. 2. The action of an upright piano according to claim 1, wherein the action is a drop action, at least a portion of which is disposed below the key, and which is actuated by the wippen being pulled up and rotated upward by the pressed key.

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