Piano with drop action

Abstract

To provide a piano with drop action which prevents lifting up and twisting of a first key near a balance pin hole when a key is depressed, and ensures stable and smooth operation of the first key and a second key when the piano has the upper first key and the lower second key.SOLUTION: A piano 1 includes: upper first keys 2A which are freely rotatably supported by balance pins 6a through balance pin holes at a rear end part, and are depressed by a player; a lower second key 2B which is freely rotatably supported in a center part and on which the first keys abut at a front end part; an action 3 which has a wippen 21 which is arranged below the second key 2B, drives a hammer 4 by upward rotation and strikes strings; a wire 33 which lifts the wippen 21 when the first key is depressed; and a keyboard presser 51W for white keys and a keyboard presser 51B for black keys which contact pin rear parts of the first keys from upward and prevent lifting of the first keys near the balance pin holes to a degree that the first keys are not twisted when the keys are depressed.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a piano with a drop action, which is an action located below the keyboard. [Background technology]

[0002] Conventionally, a piano with a drop action (hereinafter referred to as a "drop action piano") has been known, for example, as disclosed in Patent Document 1. This piano has a plurality of keys (white keys and black keys) extending in the front-to-rear direction and rotatably supported at their centers on balance pins, and an action located behind and below the keys. The configuration of the action is basically the same as that of a normal action on an upright piano; when a key is pressed, an extension lever connected to the rear end of the key rotates the wippen upward, causing the hammer to rotate backward, thereby striking the string.

[0003] In conventional drop-action pianos, the keys are supported in the center, which increases the overall length of the keys and, consequently, the depth (front-to-back length) of the piano. The applicant has already proposed a drop-action piano to address this issue (e.g., Patent Application No. 2023-057064). As shown in FIG. 5, this piano has a two-tiered keyboard, with the upper key 2A supported at its rear end by a balance pin 6a erected on a reed 6 via a balance pin hole 6b. Note that reference numeral 6c in FIGS. 5 and 6 denotes a recess formed on the underside of the first key 2A to prevent the first key 2A from interfering with the reed 6 when it rotates.

[0004] As shown in FIG. 7, the balance pin hole 6b formed in the first key 2A is composed of a lower pin receiving portion 6d and a guide portion 6e connected to its upper side. The pin receiving portion 6d is a circular hole with a horizontal cross section that opens to the underside of the first key 2A and extends slightly upward. Its diameter is set to a size that allows the balance pin 6a to engage appropriately without any rattle or sticking. In contrast, the guide portion 6e is a rectangular hole with a horizontal cross section that widens symmetrically in the front-to-back and left-to-right directions around the pin receiving portion 6d. It extends upward from the pin receiving portion 6d and opens to the top surface of the first key 2A. A pair of left and right bushing cloths 10 are attached near this opening, extending from the top surface of the first key 2A to the upper inner surface of the guide portion 6e to prevent noise and wear. With this configuration, the first key 2A is rotatably supported by the balance pin 6a with the pin receiving portion 6d of the balance pin hole 6b engaged with the balance pin 6a.

[0005] Meanwhile, the lower second key 2B is supported at its center by a bearing groove 31d of the support member 31 via a shaft 2d, and the rear end of the second key 2B and the wippen 21 of the action 3 are connected by a wire 33. When the first key 2A is pressed and the actuator pin 8 presses down on the front end of the second key 2B, the rear end of the second key 2B rotates upward, and the wire 33 lifts the wippen 21, causing the hammer 4 to rotate backward, thereby striking the string S with the hammer 4. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Jikko No. 49-2178 Summary of the Invention [Problem to be solved by the invention]

[0007] In a drop-action piano with the above-described two-tiered keyboard, as shown in FIG. 6, the upper first key 2A, unlike keys on a typical upright piano, is supported at its rear end by a balance pin 6a. No action, which also functions as a weight (reaction force), is placed behind the balance pin 6a. Therefore, when the first key 2A is fully depressed, the portion of the first key 2A indicated by arrow Y in FIG. 6 lifts off the reed 6, which tends to forcefully press the wall of the pin receiving portion 6d of the balance pin hole 6b of the first key 2A against the balance pin 6a. This slows the return of the first key 2A, impeding the smooth rotation of the first key 2A and destabilizing the movement of the second key 2B, hindering piano performance. In this specification, the forceful pressing of the wall of the pin receiving portion 6d of the balance pin hole 6b of the first key 2A against the balance pin 6a is referred to as "pushing."

[0008] The present invention has been made to solve such problems, and aims to provide a piano with drop action that, when it has an upper first key and a lower second key, can ensure stable and smooth operation of the first and second keys by preventing the first key from lifting up or twisting near the balance pin hole when the keys are pressed. [Means for solving the problem]

[0009] To achieve this object, the invention of claim 1 is characterized by comprising: a first key whose rear end is rotatably supported on a balance pin via a balance pin hole and which is pressed by a player; a second key which is arranged below the first key, rotatably supported in its center, and whose front end abuts against the first key; an action which is arranged below the second key and has a wippen which, when rotated upward, drives the hammer and strikes the strings; a connecting member which is connected to the rear end of the second key and the wippen, and which lifts and rotates the wippen upward as the rear end of the second key rotates upward in response to pressing of the first key; and a key presser which contacts from above the rear part of the first key, which is a part rearward of the balance pin, and which prevents the first key from floating up near the balance pin hole when pressed, to the extent that the first key does not twist against the balance pin.

[0010] The piano according to the present invention comprises an action including a first key to be pressed by a player, a second key disposed below the first key, and a wippen disposed below the second key, and a connecting member connected to the rear end of the second key and the wippen. The rear end of the first key is rotatably supported by a balance pin via a balance pin hole. When the first key is pressed during playing, the front end of the second key is pressed down by the first key, causing it to rotate around its center. Accordingly, the rear end of the second key rotates upward, and the connecting member lifts and rotates the wippen upward, driving the hammers to strike the strings.

[0011] Furthermore, according to the present invention, the key presser contacts the pin rear portion of the first key from above, which is the portion behind the balance pin, and when the key is pressed, the key presser prevents the first key from lifting up near the balance pin hole to the extent that the first key does not rub against the balance pin. This reliably prevents the first key from lifting up near the balance pin hole and the resulting jerking of the first key, ensuring stable and smooth operation of the first and second keys.

[0012] The invention of claim 2 is characterized in that, in the piano with drop action described in claim 1, the key presser has a block-shaped main body portion that is positioned above the rear part of the pin of the first key and extends in the left-right direction of the piano, and a contact portion that is provided on the underside of the main body at a position corresponding to the first key and makes line contact or point contact with the rear part of the pin along the width direction of the first key.

[0013] According to this configuration, the keyboard foot has a contact portion provided on the underside of the main body, and this contact portion makes line or point contact with the rear pin portion of the first key in its width direction. By making the contact portion make line or point contact in this manner, it is possible to avoid an increase in resistance when the first key rotates while the keyboard foot is in surface contact, and to smoothly press the first key with a light touch. Furthermore, because the main body of the keyboard foot extends continuously in the left-right direction of the piano and the contact portion is provided only in a position corresponding to the first key, the keyboard foot can be constructed inexpensively with a small number of parts.

[0014] The invention of claim 3 is characterized in that, in the drop action piano described in claim 2, the main body of the key presser is made of wood material, and the contact part is made of a metal pin with a circular cross section, which is arranged and glued to the underside of the main body along its length.

[0015] According to this configuration, the main body and contact portion of the keyboard foot are constructed separately, with the former being made of wood, while the latter being a metal pin with a circular cross section that is arranged and glued to the underside of the main body along its length. This configuration realizes the keyboard foot of claim 2, which has a contact portion that is attached to the underside of the main body and makes line contact with the first key. Furthermore, by appropriately selecting the wood material that makes up the main body and the metal material that makes up the contact portion, it is possible to construct a keyboard foot with desired physical properties (weight, hardness, lubricity, etc.).

[0016] The invention of claim 4 is characterized in that, in the drop action piano described in claim 2, the key presser foot is made of a synthetic resin molded product in which the main body and contact part are molded as one unit.

[0017] This configuration allows the keyboard foot, in which the main body and contact portion are integrated, to be obtained as a molded product from synthetic resin, reducing the number of processing steps and manufacturing costs.In addition, since the molded product has high dimensional accuracy, the keyboard foot can be formed with high precision.

[0018] The invention of claim 5 is characterized in that, in the drop action piano described in claim 2, a cushion is attached to the upper surface of the rear part of the pin of the first key, with which the contact part of the keyboard foot comes into contact.

[0019] According to this configuration, the cushion attached to the upper surface of the pin rear portion of the first key ensures cushioning when the keyboard presser foot comes into contact with the pin rear portion of the first key.

[0020] The invention of claim 6 is characterized in that, in a piano with drop action according to any one of claims 1 to 5, the first key is composed of a white key and a black key, the balance pins supporting the white keys and the balance pins supporting the black keys are arranged at different positions in the front-to-back direction, and the key pressers are composed of a white key key presser that comes into contact with the rear part of the pin of the white key, and a black key key presser that comes into contact with the rear part of the pin of the black key.

[0021] With this configuration, the balance pins supporting the white and black keys of the first key are positioned at different positions in the front-to-back direction, and the white key pressers that come into contact with the rear portions of the white key pins and the black key pressers that come into contact with the rear portions of the black key pins are configured separately. This configuration allows the white key pressers to press the white keys and the black key pressers to press the black keys smoothly and independently without interfering with each other. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a side view showing a keyboard device, action, hammers, etc. of a piano to which the present invention is applied in a key-released state. [Figure 2] FIG. 2 is a side view showing the piano of FIG. 1 in a key-depressed state. [Figure 3] 2A and 2B are a plan view and a side view showing the keyboard device of FIG. 1. [Figure 4] FIG. 2 is a partially enlarged side view of the arrow A portion in FIG. [Figure 5] 1 is a side view showing the keyboard device, action, hammers, etc. of a piano proposed by the applicant in a key-released state. [Figure 6] 6 is a partially enlarged side view of the portion indicated by the arrow X in FIG. 5. [Figure 7] 1A is a partially enlarged plan view showing the configuration of the first key in the vicinity of a balance pin hole, and FIG. 1B is a cross-sectional view taken along line ZZ′. DETAILED DESCRIPTION OF THE INVENTION

[0023] A preferred embodiment of the present invention will be described in detail below with reference to the drawings. As shown in Figures 1 and 2, a piano 1 to which the present invention is applied includes a keyboard 2, a drop-action action 3, and hammers 4. In the following description, the front side of the piano 1 as viewed from the player's side will be referred to as the "front," the back side as the "rear," the left side as the "left," and the right side as the "right."

[0024] As shown in Figure 3, the keyboard 2 has a number of first keys 2A (white keys 2AW and black keys 2AB) lined up in the left-right direction of the piano 1, and a number of second keys 2B (only one shown) located below each first key 2A and lined up in the left-right direction. Each first key 2A extends in the front-to-rear direction (the left-to-right direction in Figure 1), and its rear end is rotatably supported via a balance pin 6a, which is erected on a reed 6 on the shelf board 5, via a balance pin hole 6b, and its front is guided by a front pin 7. A recess 6c is formed on the underside of each first key 2A near the balance pin 6a to prevent the first key 2A from interfering with the reed 6 when it rotates.

[0025] As described above with reference to FIG. 7, the balance pin hole 6b of the first key 2A is composed of a lower pin receiving portion 6d and an upper guide portion 6e. The pin receiving portion 6d is a round hole that opens to the underside of the first key 2A and extends slightly upward. Its diameter is set to a size that allows the balance pin 6a to engage properly without any rattle or sticking. The guide portion 6e is a rectangular hole that widens symmetrically in the front-to-back and left-to-right directions around the pin receiving portion 6d. It extends upward from the pin receiving portion 6d and opens to the top surface of the first key 2A. A pair of left and right bushing cloths 10 are attached near this opening, extending from the top surface of the first key 2A to the upper inner surface of the guide portion 6e to prevent noise and wear. With this configuration, the first key 2A is rotatably supported by the balance pin 6a with the pin receiving portion 6d of the balance pin hole 6b engaged with the balance pin 6a.

[0026] As shown in Figures 3 and 4, the balance pins 6a supporting the white keys 2AW are located on the front side, and the balance pins 6a supporting the black keys 2AB are located on the rear side. A white key presser foot 51W is located above the portion immediately behind the balance pins 6a of the white keys 2AW (rear pin portion), and a black key presser foot 51B is located above the portion immediately behind the balance pins 6a of the black keys 2AB (rear pin portion). Hereinafter, when the white key presser foot 51W and the black key presser foot 51B are referred to collectively, they will be referred to as "keyboard presser foot 51."

[0027] The white key presser foot 51W is composed of a block-shaped main body 52 and multiple pins 53 attached to the main body 52. ​​The main body 52 is made of wood and has a generally rectangular cross section that is long in the vertical direction. It extends continuously in the left-right direction of the piano 1 and is fixed to the piano body at both ends. Pin mounting grooves 52a are continuously formed on the underside of the main body 52. ​​The pins 53 are made of metal such as iron and have a circular cross section. They are positioned at positions corresponding to the white keys 2AW and are partially received in and adhered to the pin mounting grooves 52a of the main body 52.

[0028] Meanwhile, cushions 54 and surface materials 55 are provided in that order on the upper surface of the rear part of the pins of each white key 2AW, and the pins 53 of the white key presser foot 51W are in line contact with the cushions 54 via the surface materials 55. The cushions 54 are made of synthetic resin with appropriate cushioning properties and are also used to adjust the height of the cushions themselves. The surface materials 55 are plate-shaped and made of synthetic resin with lubricity, and have the function of suppressing friction and noise.

[0029] Black key keyboard presser 51B is constructed similarly to white key keyboard presser 51W, and is composed of a block-shaped main body 52 that extends continuously in the left-right direction of the piano, and multiple pins 53 that are partially accommodated in and adhered to positions corresponding to black keys 2AB in pin mounting grooves 52a of main body 52. ​​Cushions 54 and surface materials 55 are provided in this order on the upper surface behind the pins of each black key 2AB, and pins 53 of white key keyboard presser 51W are in line contact with cushions 54 via surface materials 55.

[0030] An actuator pin 8 is provided at the front of the underside of the first key 2A, extending downward through the shelf board 5. A height-adjusting cap 8a is fitted to the lower end of the actuator pin 8. A bushing cloth 8b is attached to the underside of the cap 8a, and the actuator pin 8 abuts against the front end of the upper surface of the second key 2B via the bushing cloth 8b.

[0031] The second key 2B is disposed between the shelf board 5 and the bottom board 9 below it, and is rotatably supported by a support member 31. As shown in Fig. 3, the second key 2B is composed of a second key for black keys 2BB corresponding to the black keys 2AB and a second key for white keys 2BW corresponding to the white keys 2AW. The second key for black keys 2BB and the second key for white keys 2BW each have a key body 2c having the same shape and dimensions and a pair of shafts 2d, 2d provided at different positions in the front-to-rear direction of the key body 2c.

[0032] The key body 2c extends in the front-to-rear direction and has a slightly curved, V-shaped planar shape, with a linear side profile that remains constant in height except for a slightly raised rear end. An adjustment screw 32 is screwed into the rear end of the top surface of the key body 2c, and a guide hole 2e is formed just behind it, penetrating vertically. The upper end of a wire 33 (described later) is wound around the shank of the adjustment screw 32 and passed through the guide hole 2e. A slit 2f is formed in the rear end surface of the key body 2c, penetrating vertically and communicating with the guide hole 2e. A weight 34 is attached between the adjustment screw 32 and the guide hole 2e of the key body 2c.

[0033] The shafts 2d of the second keys 2B are integrally formed on the left and right sides of the key body 2c and protrude to both the left and right. The shaft 2d of the second white key 2BW is located approximately one-third of the way along the entire length of the key body 2c from the front end, and the shaft 2d of the second black key 2BB is located behind the second white key 2BW.

[0034] Meanwhile, a support member 31 is attached to the bottom plate 9. The support member 31 integrally comprises a base 31a and multiple support walls 31b (only one is shown) erected on the base 31a. The multiple support walls 31b are aligned in the left-right direction at intervals from one another. Each support wall 31b is formed with a white key bearing groove 31dW on the front side and a black key bearing groove 31dB on the rear side, each of which opens upward and extends diagonally.

[0035] 3, the second white key 2BW is rotatably supported by the support member 31 with its key body 2c housed between the corresponding two support walls 31b and its shafts 2d passing through the corresponding white key bearing grooves 31dW and 31dW and engaging with the bottom. Similarly, the second black key 2BB is rotatably supported by the support member 31 with its key body 2c housed between the corresponding two support walls 31b and its shafts 2d passing through the corresponding black key bearing grooves 31dB and 31dB and engaging with the bottom.

[0036] The action 3 is located behind and below the first key 2A and the second key 2B, and has a wippen 21 provided for each first key 2A. The wippen 21 is rotatably supported at its rear end on a center rail 22 extending laterally via a wippen flange 21a. A mounting screw 23 having a ring portion 23a is screwed into the front end of the wippen 21, and the lower end of a wire 33 engages with and is attached to the ring portion 23a.

[0037] The wire 33 is made of a material with suitable flexibility and strength, such as a high-strength nylon core coated with fiber or carbon, and is stretched between the adjustment screw 32 of the second key 2B and the mounting screw 23 of the wippen 21. The degree of tension is adjusted by turning the adjustment screw 32 and changing the amount of wire 33 wound around its shaft.

[0038] The structure of the action 3, other than the wippen 21, is basically the same as that of a regular upright piano action, and will be briefly explained below. The action 3 has a jack 24, a butt 25, and a damper lever 26, which are provided for each first key 2A.

[0039] The jack 24 is formed in an L-shape with a base extending forward and a hammer thrust portion extending upward from the rear end of the base, and is rotatably attached to the center of the wippen 21 at the corners of both portions.

[0040] The butt 25 is rotatably supported on the center rail 22 via a butt flange 25a, and when the first key 2A is released, the hammer thrust portion of the jack 24 abuts against it from below. A hammer shank 4a of the hammer 4 stands on the upper surface of the butt 25, and a hammer head 4b is provided at its upper end. When the first key 2A is released, the hammer head 4b faces the string S stretched behind it.

[0041] The damper lever 26 extends vertically, its center portion being rotatably supported on the center rail 22 via a damper flange 26a, and a damper 26b is provided at its upper end. When the first key 2A is released, the damper 26b presses against the string S, and a spoon 27, which is erected at the rear end of the wippen 21, faces the lower end of the damper lever 26 from the front.

[0042] Next, the operation of the piano 1 configured as described above will be described. When a player presses the first key 2A from the key-released state shown in FIG. 1, the first key 2A rotates downward (clockwise in FIG. 1) around the balance pin 6a at its rear end and presses down on the front end of the second key 2B via the actuator pin 8. As a result, the second key 2B rotates clockwise around the bottom of the bearing groove 31d with which the shaft 2c engages, just like the first key 1A. As its rear end moves upward, it lifts the wippen 21 via the wire 33. Accordingly, the wippen 21 rotates upward, and the jack 24 attached to the wippen 21 pushes up the butt 25, causing the hammer 4, which is integral with the butt 25, to rotate backward and strike the string S (the state shown in FIG. 2).

[0043] Furthermore, as the wippen 21 rotates, the spoon 27 integral with it moves rearward and presses against the lower end of the damper lever 26, causing the damper lever 26 to rotate clockwise, and the damper 26b moves away from the string S, ensuring that sound is produced by the vibration of the string S.

[0044] Furthermore, according to this embodiment, the key holder 51 contacts the pin rear portion of the first key 2A from above, which is the portion behind the balance pin 6a, and when the key is pressed, the key holder 51 prevents the first key 2A from lifting up in the arrow Y portion (FIG. 4) to the extent that the first key 2A does not rub against the balance pin 6a. This reliably prevents the first key 2A from lifting up near the balance pin 6a and the resulting clunking of the first key, ensuring stable and smooth operation of the first key 2A and second key 2B.

[0045] Furthermore, because the pin 53 provided on the underside of the keyboard retainer 51 makes line contact with the rear pin portion of the first key 2A in the width direction, an increase in resistance when the first key rotates while the keyboard retainer is in surface contact can be avoided, allowing the first key 2A to be pressed smoothly with a light touch. Also, because the main body 52 of the keyboard retainer 51 extends continuously in the left-right direction of the piano 1, and the pin 53 is provided only in a position corresponding to the first key 2A, the keyboard retainer 51 can be constructed inexpensively with a small number of parts.

[0046] Furthermore, the white key presser foot 51W, which comes into contact with the rear portion of the pin of the white key 2AW of the first key 2A, and the black key presser foot 51B, which comes into contact with the rear portion of the pin of the black key 2AB, are configured separately from each other, so the pressing action of the white key 2AW by the white key presser foot 51W and the pressing action of the black key 2AB by the black key presser foot 51B can be performed smoothly and independently of each other without interfering with each other.

[0047] The present invention is not limited to the described embodiment and can be implemented in various forms. For example, in the embodiment, the key foot 51 is composed of a main body 52 made of wood and a metal pin 53 as a contact portion bonded to the main body 52. ​​Alternatively, the key foot may be composed of a molded product made of synthetic resin (e.g., polyacetal) in which the main body and contact portion are integrally molded, thereby reducing the number of steps required to process the key foot and the manufacturing costs. Furthermore, since the molded product has high dimensional accuracy, the key foot can be formed with high precision.

[0048] In addition, in the embodiment, the key foot 51 is in line contact with the pin rear portion of the second key 2A via the pin 53, but this is not limited to this and point contact is also possible. This prevents an increase in resistance when the first key rotates when the key foot is in surface contact, just like in the case of line contact, and allows the first key to be pressed smoothly with a light touch.

[0049] Furthermore, the materials of the components shown in the embodiments are merely examples, and it goes without saying that other appropriate materials may be used. In addition, the detailed configuration may be changed as appropriate within the scope of the spirit of the present invention. [Explanation of symbols]

[0050] 1. Piano 2A 1st key 2AW white key 2AB black key 2B 2nd key 3 Actions 4 Hammer 6a Balance pin 6b Balance pin hole 21 Whippen 33 Wire rod (connecting material) 51 Keyboard foot 51W White Keys 51B Black Keys Presser Foot 52 Main body 53 pin (contact part) 54 Cushion S string

Claims

1. a first key rotatably supported at its rear end on a balance pin via a balance pin hole and pressed by a player; a second key disposed below the first key, rotatably supported at a center portion thereof, and having a front end portion thereof in contact with the first key; an action having a wippen disposed below the second key, the wippen rotating upward to drive a hammer and strike the string; a connecting member that is connected to a rear end of the second key and the wippen, and that lifts and rotates the wippen upward as the rear end of the second key rotates upward in response to depression of the first key; a key presser that contacts from above a pin rear portion of the first key that is a portion rearward of the balance pin, and prevents the first key from lifting up near the balance pin hole when the first key is pressed, to the extent that the first key is not twisted; A drop action piano comprising:

2. 2. The piano with drop action according to claim 1, wherein the keyboard presser has a block-shaped main body portion that is disposed above the rear pin portion of the first key and extends continuously in the left-right direction of the piano, and a contact portion that is provided on the underside of the main body at a position corresponding to the first key and that makes line or point contact with the rear pin portion along the width direction of the first key.

3. 3. A piano with drop action according to claim 2, wherein the main body of the keyboard presser foot is made of wood, and the contact portion is made of metal and formed in the shape of a pin with a circular cross section, and is arranged and glued to the underside of the main body along its length.

4. 3. The piano with drop action according to claim 2, wherein the keyboard presser foot is made of a synthetic resin molded product in which the main body and the contact portion are integrally molded.

5. 3. The piano with drop action according to claim 2, wherein a cushion is attached to an upper surface of the rear portion of the pin of the first key, with which the contact portion of the key presser foot comes into contact.

6. 6. The piano with drop action according to claim 1, wherein the first keys are composed of white keys and black keys, the balance pins supporting the white keys and the balance pins supporting the black keys are arranged at different positions in the front-to-rear direction, and the key pressers are composed of a white key key presser that comes into contact with the rear portions of the pins of the white keys and a black key key presser that comes into contact with the rear portions of the pins of the black keys.

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