Keyboard device for keyboard instruments

Abstract

To provide a keyboard device for a keyboard musical instrument capable of compactly configuring the keyboard device itself, easily performing the mounting and replacement work of a let-off member, and further increasing the degree of freedom in setting the start timing and the continuation time of let-off.SOLUTION: Disclosed is a keyboard device for a keyboard musical instrument having a let-off function which includes: a keyboard chassis having a plurality of partition walls; a plurality of keys; and a plurality of hammers rotating in conjunction with the key depression. In one of two partition walls 14, 14 adjacent to each other and a hammer 31 arranged therebetween, a let-off member 51 is mounted, and in the other of two partition walls 14, 14 adjacent to each other and the hammer 31 arranged therebetween, an engaging part 39 is provided, which is for imparting let-off feeling to the touch feeling of the depressed key 2 by being temporarily engaged with the let-off member 51 during the rotation of the hammer 31 accompanying the key depression.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a keyboard device for a keyboard instrument, such as an electronic piano, that has a let-off function that provides a let-off feel similar to that of an acoustic piano. [Background technology]

[0002] A known example of this type of keyboard device is the keyboard device disclosed in Patent Document 1, which was previously filed by the present applicant. This keyboard device includes a keyboard chassis, keys extending in the front-rear direction and pivotally supported at their rear ends on the keyboard chassis, and hammers mounted below the keys and pivoting in conjunction with the keys. The hammers are pivotally supported on hammer spindles mounted on the keyboard chassis. When a key is pressed, a predetermined portion forward of the hammer spindle is depressed by the key, causing a portion behind the hammer spindle to rise. The hammers are provided with engagement projections that protrude upward at predetermined positions behind the hammer spindles, while the keyboard chassis is provided with let-off members made of an elastic material that protrude diagonally downward and forward on a horizontal plate portion located between the keys and the hammers.

[0003] When a key is pressed, the hammer rotates and the engagement protrusion rises, temporarily engaging the hammer's engagement protrusion with the let-off member, applying a temporary resistance force to the rotating hammer. This gives the touch of the key corresponding to that hammer a let-off feel similar to that of an acoustic piano. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-27854 Summary of the Invention [Problem to be solved by the invention]

[0005] As described above, the above keyboard device provides engagement protrusions on the hammers to achieve a let-off feel, while also providing let-off members between the hammers and the keys. This requires a relatively large space between the hammers and the keys, which increases the height of the keyboard device. Furthermore, because the let-off members are relatively small and are located between the keys and the hammers, the installation and replacement of the let-off members on the keyboard chassis during assembly and maintenance of the keyboard device is cumbersome and time-consuming. Furthermore, the engagement protrusions on the hammers and the let-off members on the flat plate of the keyboard chassis limit the flexibility in setting the timing and duration of the let-off when a key is pressed. Therefore, the above keyboard device leaves room for improvement.

[0006] The present invention has been made to solve the above-mentioned problems, and aims to provide a keyboard device for a keyboard instrument that can be configured compactly, that allows for easy installation and replacement of let-off components, and that allows for greater freedom in setting the start timing and duration of let-off. [Means for solving the problem]

[0007] In order to achieve the above object, the invention of claim 1 is a keyboard device for a keyboard instrument having a let-off function that provides a let-off feeling similar to that of an acoustic piano, comprising a keyboard chassis having a plurality of partition walls each extending in the front-rear direction and arranged at predetermined intervals in the left-right direction, a plurality of keys each extending in the front-rear direction and arranged at positions corresponding to the spaces between adjacent partition walls at the top of the keyboard chassis, and a plurality of keys each extending in the front-rear direction and arranged below the corresponding key, On the keyboard chassis Between adjacent partition walls Left and right The hammer shaft is designed to extend , through a predetermined bearing portion A plurality of hammers are supported rotatably and rotate in conjunction with the corresponding keys when the keys are pressed. wall, and one of the hammers disposed between the two partition walls is provided with a let-off member. Taken The two compartments are attached next to each other. wall, The other of the hammers arranged between the two partition walls is attached to the let-off member during the rotation of the hammer accompanying key depression. In contact Temporarily engaging So, rotation resistance acts on the hammer. The key is characterized by having an engagement portion for imparting a let-off feel to the touch of the pressed key.

[0008] According to this configuration, the keyboard chassis has a plurality of partition walls each extending in the front-rear direction and arranged at a predetermined interval in the left-right direction, and a plurality of keys are arranged at positions corresponding to the spaces between adjacent partition walls on the upper part of the keyboard chassis. Left and right The hammer is attached to the extending hammer support shaft. Through the specified bearing The hammers are supported rotatably, and when a key is pressed, each hammer rotates in conjunction with the corresponding key. A let-off member is provided on one of the partition wall and the hammer. Taken The other of the partition wall and the hammer is provided with an engagement portion that can be engaged with the let-off member. When the hammer rotates with a key depression, the engagement portion engages with the let-off member. In contact This temporary engagement creates a resistance to the hammer as it rotates, temporarily increasing the weight of the key touch and giving the key a let-off feel similar to that of an acoustic piano.

[0009] Since one of the let-off member and the engagement portion is provided on a partition wall located to the side of the hammer, there is no need to secure a large space between the hammer and the key, unlike conventional arrangements in which the let-off member or the engagement portion is provided on or above the hammer. This allows the keyboard device with the above-mentioned let-off function to be constructed compactly. In addition, by arranging the let-off member and the engagement portion in the above-mentioned positional relationship, it is relatively easy to set the start timing and duration of the let-off, increasing the degree of freedom in setting it. do.

[0010] The invention of claim 2 is characterized in that, in the keyboard device of the keyboard instrument described in claim 1, the let-off members are made of an elastic material and are attached to two adjacent partition walls, respectively, and the engagement portions are provided on the left and right sides of the hammer, respectively, and are configured to be able to engage with the let-off members attached to the two partition walls while the hammer rotates when the key is pressed.

[0011] According to this configuration, let-off members made of an elastic material are attached to two adjacent partition walls, respectively. Meanwhile, engagement portions are provided on the left and right side surfaces of the hammer. When the hammer rotates in response to a key depression, the left and right engagement portions of the hammer engage with the left and right let-off members attached to the partition walls on both sides, respectively. By engaging the left and right engagement portions of the hammer with the left and right let-off members in this way, the hammer can be smoothly rotated while suppressing lateral vibration, and a stable let-off feel can be achieved.

[0012] The invention of claim 3 is characterized in that, in the keyboard device of the keyboard instrument described in claim 2, the let-off member has an attachment portion that is attached from below to a predetermined position on the partition wall, and an engaging convex portion that is provided below this attachment portion and has a curved surface that is convexly curved toward the hammer that is to engage with it.

[0013] According to this configuration, the let-off member has the above-mentioned mounting portion and engaging protrusion. The mounting portion is attached to a predetermined position on the partition wall from below, making it easy to attach the let-off member to the partition wall. The engaging protrusion has a curved surface that curves convexly toward the hammer, and when the hammer rotates in response to a key depression, the engaging portion of the hammer abuts against the curved surface of the engaging protrusion of the let-off member, causing a reaction force from the engaging protrusion to act on the hammer. This applies rotational resistance to the hammer, imparting a let-off feel to the touch of the key corresponding to that hammer. In this way, the let-off member of the above configuration makes it easy to obtain a let-off feel.

[0014] The invention of claim 4 is characterized in that, in the keyboard device of the keyboard instrument described in claim 3, the mounting portion of the let-off member is open upward and formed in a concave shape that can clamp the partition wall from both the left and right sides, and the partition wall has a retaining portion that penetrates the mounting portion from above and holds the mounting portion in a non-removable state.

[0015] According to this configuration, the mounting portion of the let-off member is formed in a concave shape that opens upward and can clamp the partition wall from both the left and right, and the partition wall is provided with anti-slip portions that penetrate the mounting portion from above. Therefore, the let-off member attached to the partition wall clamps the partition wall from both the left and right via the mounting portions and is held in a prevented state. As a result, the let-off member is firmly attached to the partition wall in the left-right and up-down directions, and will not come off the partition wall even if the engagement portions of the hammers repeatedly engage with each key press.

[0016] The invention of claim 5 is characterized in that, in the keyboard device of the keyboard instrument described in claim 4, the keyboard chassis is provided with a locking claw that locks the mounting portion of the let-off member attached to the partition wall from below.

[0017] According to this configuration, when the let-off member is attached to the partition wall, the attachment portion of the let-off member is engaged from below by the locking claw, which, combined with the aforementioned anti-pullout portion, allows the let-off member to be attached to the partition wall even more firmly.

[0018] The invention of claim 6 is characterized in that, in the keyboard device of a keyboard instrument described in any one of claims 3 to 5, the engaging protrusions are composed of two engaging protrusions arranged at a distance from each other in the left-right direction and capable of engaging with two hammers arranged on the left and right sides of the partition wall to which the let-off member is attached.

[0019] According to this configuration, the engagement protrusion is composed of two engagement protrusions arranged at a distance from each other in the left-right direction. Furthermore, of these two engagement protrusions, the left engagement protrusion is engageable with a hammer arranged on the left side of the partition wall to which the let-off member is attached, while the right engagement protrusion is engageable with a hammer arranged on the right side of the partition wall. By making two adjacent hammers engageable with a single let-off member in this way, the single let-off member can impart a let-off feel to the two keys corresponding to the two hammers.

[0020] The invention according to claim 7 is characterized in that in the keyboard device for a keyboard instrument according to claim 6, the two engaging protrusions are arranged in a state where they are offset in the front-rear direction.

[0021] With this configuration, the two engaging protrusions on the single let-off member are positioned offset in the front-to-rear direction, so that even when, for example, two adjacent keys are pressed simultaneously or successively and the hammers corresponding to those keys respectively engage with the two engaging protrusions on the single let-off member, interference such as collision between the two engaging protrusions can be suppressed, thereby providing a stable let-off feel even when two adjacent keys are pressed.

[0022] The invention of claim 8 is characterized in that, in the keyboard device of a keyboard instrument described in any one of claims 3 to 7, the let-off member is configured so that the resistance force acting on the hammer when the engagement portion of the hammer engages with the engagement convex portion from above is smaller than the resistance force acting on the hammer when the engagement portion engages with the engagement convex portion from below.

[0023] According to this configuration, when a key is pressed, the hammer rotates in a predetermined direction, causing the engagement portion of the hammer to engage with the engagement protrusion of the let-off member from below (hereinafter referred to as the "first engagement"), and then the engagement is released. When the pressed key is released, the hammer rotates in the opposite direction, causing the engagement portion of the hammer to engage with the engagement protrusion of the let-off member from above (hereinafter referred to as the "second engagement"), and then the engagement is released. In other words, with one key press, the engagement portion of the hammer engages with the let-off member twice. According to the above configuration, the let-off member is configured so that the resistance force acting on the hammer during the second engagement is smaller than the resistance force acting on the hammer during the first engagement. This allows the first engagement when the key is pressed to produce a distinct let-off feeling, such as a click. Note that the second engagement when the pressed key is released does not produce the above-mentioned let-off feeling because the resistance force acting on the hammer is smaller.

[0024] The invention according to claim 9 is 3 In the keyboard device of the keyboard instrument described in any one of claims 1 to 8, the multiple let-off members are arranged in a line corresponding to the multiple partition walls to which they are to be attached, and are prepared as unit parts integrally molded in a state where they are connected to a belt-shaped connecting part via each of their mounting parts, and the unit parts are formed such that, when the keyboard device is assembled, after the multiple let-off members are attached to the multiple partition walls, the connecting part is Multiple Let-off material Each of The device is characterized in that it is configured to be separated from the

[0025] According to this configuration, the multiple let-off members are prepared as a unit component integrally molded in a state in which they are connected to the belt-shaped connecting portion via their respective mounting portions. In this unit component, the multiple let-off members are arranged in a line so as to correspond to the multiple partition walls to which they are to be attached. Therefore, when assembling the keyboard device, the multiple let-off members are attached to the corresponding partition walls, and then the connecting portions of the unit component are MultipleLet-off material Each of By separating the let-off member from the partition wall, the work of attaching the let-off member to the partition wall can be carried out efficiently.

[0026] The invention of claim 10 is characterized in that, in the keyboard device of the keyboard instrument described in claim 9, each of the multiple let-off members is given a symbol corresponding to the partition wall to which it is to be attached.

[0027] According to this configuration, each let-off member is assigned a symbol corresponding to the partition wall to which it should be attached. Therefore, even if multiple let-off members are removed from the partition walls, for example, during maintenance of the keyboard device, each let-off member can be easily attached to the appropriate partition wall by checking the symbol assigned to the let-off member.

[0028] The invention of claim 11 is characterized in that, in the keyboard device of the keyboard instrument described in claim 1, the let-off member is made of an elastic material, is attached to the hammer, and is formed so as to protrude outward from the left and right sides of the hammer, and the engagement portions are provided on the opposing surfaces of two adjacent partition walls, respectively.

[0029] According to this configuration, a let-off member made of an elastic material is attached to the hammer and protrudes outward from the left and right side surfaces of the hammer. Meanwhile, engagement portions are provided on the opposing surfaces of two adjacent partition walls. When the hammer rotates in response to a key depression, the let-off members protruding from the left and right side surfaces of the hammer engage with the engagement portions provided on the partition walls on both sides of the hammer. Because the hammer's let-off member engages with the engagement portions on both partition walls in this way, a good let-off feel can be achieved through this engagement.

[0030] The invention according to claim 12 is a keyboard device for a keyboard instrument according to claim 11, wherein the engagement portion is composed of two engagement portions formed so as to protrude from predetermined positions on the opposing surfaces of two adjacent partition walls, and the let-off member is composed of a fixed portion fixed to the top of the hammer, two left and right side walls connected to this fixed portion and hanging down along the left and right side surfaces of the hammer, respectively, and two left and right inclined pieces protruding diagonally upward by a predetermined length from these two left and right side walls, The present invention is characterized by having the following.

[0031] According to this configuration, the engagement portion is composed of two engagement portions protruding from predetermined positions on the opposing surfaces of two adjacent partition walls. Meanwhile, the let-off member has the above-mentioned fixed portion, two left and right side walls, and two left and right inclined pieces. During the rotation of the hammer in response to a key depression, the left and right inclined pieces of the let-off member engage with the engagement portions of the partition walls on both sides from below, causing a reaction force from both engagement portions to act on the hammer. This creates a rotational resistance on the hammer, allowing the touch of the key corresponding to that hammer to be stably imparted with a let-off feel. During the rotation of the hammer in response to the release of a depressed key, the left and right inclined pieces of the let-off member engage with the engagement portions of the partition walls on both sides from above, but because each inclined piece protrudes diagonally upward from the hammer-side side wall, the rotational resistance acting on the hammer is smaller than when the inclined pieces of the let-off member engage with the engagement portions from below. [Brief explanation of the drawings]

[0032] [Figure 1] 1A and 1B are perspective views showing a part (for one octave) of a keyboard device of an electronic piano to which the present invention is applied, in which (a) shows the appearance of the keyboard device, and (b) shows a state in which keys other than the white and black keys on the left end are omitted. [Figure 2] 1(b) is a perspective view showing the keyboard device shown in FIG. 1(b) with the white keys and black keys, together with their respective key support mechanisms, removed from the keyboard chassis. FIG. [Figure 3]1(b) is a cross-sectional view taken along line AA of the keyboard device shown in FIG. 1(b). [Figure 4] 1A and 1B are perspective views showing a white key and a key support mechanism, in which FIG. 1A shows the white key and the key support mechanism connected together, and FIG. 1B shows the white key and the key support mechanism disassembled. [Figure 5] 1A and 1B are perspective views showing the black key and the key support mechanism, in which FIG. 1A shows the black key and the key support mechanism connected together, and FIG. 1B shows the black key and the key support mechanism disassembled. [Figure 6] 1A and 1B are diagrams for explaining the operation of a white key in a keyboard device, in which FIG. 1A shows a key-released state and FIG. 1B shows a key-depressed state. [Figure 7] 1A and 1B are diagrams for explaining the operation of black keys in a keyboard device, in which (a) shows the key-released state and (b) shows the key-depressed state. [Figure 8] 1A and 1B are diagrams for explaining the main parts of the present invention, in which (a) is a plan view of the chassis body of the keyboard chassis in which the let-off members of the first embodiment are attached to all ribs, and (b) is a cross-sectional view along line BB. [Figure 9] FIG. 10 is a perspective view showing the chassis body viewed from diagonally below, with the plurality of let-off members at the center, with the two let-off members on the left side removed. [Figure 10] 1(a) and 1(b) are perspective views showing the state when the type A let-off member is viewed obliquely from above and below, and 1(c) and 1(d) are perspective views showing the type B let-off member in the same manner. [Figure 11] (a) is a front view of the let-off member, (b) is a right side view of the let-off member of (a), (c) is a front view showing the let-off member attached to a rib, and (d) is a right side view of the let-off member of (c). [Figure 12] FIG. 2(a) is a perspective view of the first arm, and FIG. 2(b) is a right side view of the first arm. [Figure 13] FIG. 10 is a plan view partially showing the chassis main body to which let-off members are attached to all of the ribs and to which all of the first arms are attached. [Figure 14]10A to 10C are diagrams for sequentially explaining the operation of the let-off member caused by the rotation of the first arm in response to a key depression. [Figure 15] This is an oblique view showing a unit part in which multiple let-off members are integrally molded before being attached to the ribs of the chassis body during assembly of the keyboard device, (a) as seen from diagonally above, and (b) as seen from diagonally below. [Figure 16] 10(a) is a perspective view showing a first arm to which a let-off member of a second embodiment is attached, and FIG. 10(b) is a perspective view showing a state in which the let-off member has been removed from the first arm of FIG. [Figure 17] 10A and 10B are views showing a let-off member of a second embodiment, in which (a) is a perspective view and (b) is a front view. [Figure 18] 10A and 10B are diagrams illustrating the relationship between the let-off member of the second embodiment and the engagement portions of adjacent ribs. [Figure 19] 10A and 10B are diagrams illustrating the operation of the let-off member caused by the rotation of the first arm accompanying key depression. DETAILED DESCRIPTION OF THE INVENTION

[0033] A preferred embodiment of the present invention will be described in detail below with reference to the drawings. Figure 1(a) shows only one octave of a keyboard device 1 of an electronic piano to which the present invention is applied. In the following explanation, the basic configuration and operation of the keyboard device 1 will be explained first, and then the main parts of the present invention will be explained.

[0034] Figure 1(b) shows the keyboard device 1 of Figure 1(a) with all keys 2 omitted except for the white key 2a and black key 2b on the left end, and Figure 2 shows the white key 2a and black key 2b removed from the keyboard chassis 4 together with the key support mechanism 6.

[0035] This keyboard device 1 includes a keyboard chassis 4, a plurality of keys 2 consisting of white keys 2a and black keys 2b arranged in a row in the left-right direction, a key support mechanism 6 rotatably attached to the keyboard chassis 4 for each key 2 and supporting the corresponding key 2 from below, and a key switch 3 for detecting key depression information for each key 2.

[0036] The keyboard chassis 4 includes a chassis main body 4a made of a resin molded product of a predetermined shape, obtained by injection molding a predetermined resin material (e.g., ABS resin). As shown in Figure 3, the chassis main body 4a has a front portion 11, a middle portion 12, and a rear portion 13, all of which are formed to extend in the left-right direction (the left-right direction in Figure 3(a)) as a whole, and are integrally formed with a plurality of ribs 14 spaced apart in the left-right direction and each extending in the front-to-rear direction. In the following description, the front portion 11, middle portion 12, and rear portion 13 of the chassis main body 4a of the keyboard chassis 4 will be referred to as the "chassis front portion 11," the "chassis middle portion 12," and the "chassis rear portion 13," respectively.

[0037] The chassis front section 11 primarily guides the white keys 2a when they are pressed and regulates the upper and lower limit positions of their front ends. A plurality of white key guides 11a are arranged side-by-side in the left-right direction on the chassis front section 11. Each white key guide 11a is inserted from below into the corresponding white key 2a to prevent the white key 2a from swaying sideways. The chassis front section 11 also has engagement holes 11b, 11b penetrating vertically on both the left and right sides of each white key guide 11a. Two upper limit position regulation sections 21, 21 (described later) of the white key 2a penetrate the engagement holes 11b, 11b, respectively. Furthermore, the chassis front section 11 is provided with a stopper mounting section 11c at its front end, which protrudes forward and extends laterally across the entire chassis body 4a. An upper limit key stopper 16a and a lower limit key stopper 16b for the white keys are attached to the lower and upper surfaces of the stopper mounting section 11c, respectively, so as to extend laterally. In addition, a stopper mounting portion 11d for the black keys is provided at a predetermined position behind the white key guide 11a on the front part 11 of the chassis, extending in the left-right direction across the entire chassis body 4a, and an upper key limit stopper 17 for the black keys is attached to this stopper mounting portion 11d so as to extend in the left-right direction.

[0038] The chassis intermediate section 12 primarily guides the black keys 2b when pressed and swingably supports the first and second arms 31 and 32 (described later) of the key support mechanisms 6a, 6b for the white and black keys. The chassis intermediate section 12 has a flat, plate-like section 12a extending in the left-right direction and multiple black key guides 12b standing on the flat section 12a and spaced appropriately apart in the left-right direction. Each black key guide 12b is inserted into each black key 2b from below to prevent the black key 2b from swaying sideways. The front of the chassis intermediate section 12 also has a first arm support section 18 that supports the first arm 31 of the key support mechanism 6. The first arm support section 18 is supported by multiple first support shafts 18a (each extending in the left-right direction between adjacent ribs 14). (Hammer spindle)The chassis intermediate section 12 has a first support shaft 18a, and a first arm 31 is swingably supported by the first support shafts 18a. Furthermore, a second arm support section 19 is provided at the rear of the chassis intermediate section 12 to support a second arm 32 of the key support mechanism 6. The second arm support section 19 has a plurality of second support shafts 19a provided between adjacent ribs 14, 14 to extend in the left-right direction. The plurality of second support shafts 19a are arranged on the same axis extending in the left-right direction, at a position rearward and higher than the first support shaft 18a, and the second arm 32 is swingably supported by the second support shafts 19a. A first arm lower limit stopper 10b extending in the left-right direction across the entire chassis main body 4a is provided at a predetermined position on a middle rail 8 (described later) provided below the chassis intermediate section 12.

[0039] The key switch 3 is attached to the bottom of the keyboard chassis 4, between the chassis front section 11 and the chassis middle section 12. The key switch 3 is composed of a horizontally elongated printed circuit board 3a extending in the left-right direction, and multiple switch bodies 3b made of rubber switches attached to the printed circuit board 3a for each key 2 and pressed by a first arm 31 when the key is pressed.

[0040] The chassis rear section 13 primarily guides the key 2 vertically at its rear end while preventing lateral movement, and regulates the upper limit position of the rear end of the first arm 31. As shown in FIGS. 2 and 3(a), the chassis rear section 13 has multiple partition walls 13a spaced at predetermined intervals in the left-right direction to separate adjacent keys 2. Also, as shown in FIG. 3(b), a first arm upper limit stopper 10a extending left-right across the entire chassis main body 4a is provided at a predetermined position on the upper part of the chassis rear section 13. This first arm upper limit stopper 10a and the first arm lower limit stopper 10b provided on the chassis intermediate section 12 regulate the upper limit position and the lower limit position, respectively, of the first arm 31, which functions as a hammer for applying a touch weight to the key 2, when the first arm 31 rotates upward and downward. Furthermore, a metal cover plate 15 is attached to the upper part of the chassis rear part 13, extending in the left-right direction across the entire chassis body 4a and arranged to cover the rear end of the key 2.

[0041] 2 and 3(a), the chassis main body 4a of the keyboard chassis 4 configured as described above is provided with a plurality of first openings 5a that open upward and forward, and a plurality of second openings 5b that also open upward. The first arm 31 of the key support mechanism 6 engages with the first support shaft 18a from the outside through each of the first openings 5a, and the second arm 32 engages with the second support shaft 19a from the outside through each of the second openings 5b.

[0042] In the keyboard chassis 4, multiple chassis bodies 4a are connected to one another in a line up in the left-right direction, and are placed on and screwed to metal front rails 7, middle rails 8, and rear rails 9 that extend left-right and are arranged at a predetermined distance from one another in the front-to-rear direction. The keyboard chassis 4 is then fixed to a shelf board (not shown) of the electronic piano via the front rails 7 and rear rails 9.

[0043] Next, the key 2 and the key support mechanism 6 will be described. FIG. 4(a) shows an enlarged view of the white key 2a and its key support mechanism 6a, while FIG. 4(b) shows them exploded. As shown in the figure, the white key 2a is formed by injection molding a specific resin material (e.g., AS resin) to extend a specific length in the front-to-rear direction and to have a hollow shape that opens downward. The front end of the white key 2a is provided with a pair of left and right upper limit position restrictors 21, 21 that extend downward from the left and right side walls and are formed so that their lower ends are bent forward. As described above, these upper limit position restrictors 21, 21 are engaged in a state in which they penetrate the left and right engagement holes 11b, 11b of the chassis front part 11, respectively.

[0044] Additionally, a front-key connecting portion 22 is provided at the front of the white key 2a, at a predetermined position rearward of the upper limit restriction portion 21, to connect to the first arm 31 of the key support mechanism 6a. This front-key connecting portion 22 has a U-shaped connecting recess 22a with an elongated side surface that opens forward. A key-side noise suppression member 20 is attached to this connecting recess 22a, covering its entire inner circumferential surface, to suppress noise generated when a connecting shaft 35b (described later) of the first arm 31 slides within the connecting recess 22a.

[0045] Furthermore, a key rear connector 23 is provided at the rear of the white key 2a, which is connected to the second arm 32 of the key support mechanism 6a. This key rear connector 23 hangs down from the center of the white key 2a in the left-right direction and has a plate-like connector body 23a with a predetermined thickness in the left-right direction, and a pair of left and right engaging protrusions 23b, 23b that protrude coaxially from the left and right sides of the connector body 23a. In addition, a tool insertion hole 24 is formed at the rear of the white key 2a, penetrating vertically. This tool insertion hole 24 is used to insert a predetermined tool from above when releasing the connection between the white key 2a and the second arm 32 of the key support mechanism 6a, for example during maintenance of the keyboard device 1.

[0046] On the other hand, the key support mechanism 6a includes a first arm 31 and a second arm 32 that are engaged with each other and connected to the front-key connecting portion 22 and the rear-key connecting portion 23 of the white key 2a, respectively.

[0047] As shown in FIG. 4(b), the first arm 31 is composed of an arm body 33 and two weights 34, 34 attached to the arm body 33. The arm body 33 is a resin molded product of a predetermined shape, typically obtained by injection molding a predetermined resin material (e.g., polyacetal). The arm body 33 extends a predetermined length in the front-to-rear direction, and its front end is provided with a first-arm front connector 35 that connects to the front-side connector 22 of the white key 2a. The first-arm front connector 35 has a box-shaped box portion 35a that opens upward and forward, and a connecting shaft 35b that extends left and right and connects the front upper ends of the left and right side walls of the box portion 35a. The connecting shaft 35b is connected to the connecting recess 22a of the front-side connector 22 of the white key 2a so as to be rotatable and slidable in the front-to-rear direction.

[0048] The arm main body 33 also has a U-shaped bearing 36 with a downwardly open side at a predetermined position immediately rearward of the first arm front connecting portion 35, and this bearing 36 rotatably engages with the first support shaft 18a of the keyboard chassis 4. Furthermore, the arm main body 33 has a first arm rear connecting portion 37 at a predetermined position rearward of the bearing 36, which connects to the second arm 32. Specifically, the first arm rear connecting portion 37 has a connecting shaft 37a that extends in the left-right direction and has both ends that protrude outward beyond the left and right side surfaces of the arm main body 33. Both ends of this connecting shaft 37a engage with connecting recesses 45b, 45b of a second arm front connecting portion 45 of the second arm 32, which will be described later.

[0049] Two elongated plate-like weights 34, 34 are attached to weight attachment portion 38 at the rear of arm main body 33, sandwiching weight attachment portion 38 from both sides. Each weight 34 is made of a material (e.g., a metal such as iron) with a higher specific gravity than arm main body 33, and is formed into a predetermined shape by pressing a metal plate, for example.

[0050] The second arm 32 is made of a resin molded product of a predetermined shape, which is injection molded from the same resin material as the arm body 33 of the first arm 31. The second arm 32 is shorter than the first arm 31 and extends a predetermined length in the front-to-rear direction. The second arm 32 also has a C-shaped bearing portion 41 near the center in the longitudinal direction, with the side surface opening forward, and this bearing portion 41 rotatably engages with the second support shaft 19a of the keyboard chassis 4.

[0051] Additionally, a second-arm rear connecting portion 42 that connects to the key rear connecting portion 23 of the white key 2a is provided at the rear of the second arm 32. This second-arm rear connecting portion 42 is bifurcated, with two left and right connecting arms 43, 43 that extend parallel to each other a predetermined length along the length of the second arm 32. A connecting hole 43a that penetrates in the left-right direction is formed at the rear end of each connecting arm 43. Between their rear ends, the connecting arms 43, 43 sandwich the connecting main body 23a of the key rear connecting portion 23 of the white key 2a, and each connecting hole 43a rotatably fits into the corresponding engaging protrusion 23b of the key rear connecting portion 23.

[0052] Furthermore, a second arm front connecting portion 45 is provided on the front portion of the second arm 32, which is connected to the first arm rear connecting portion 37 of the first arm 31. This second arm front connecting portion 45 has a pair of left and right connecting pieces 45a, 45a spaced a predetermined distance from each other in the left-right direction, and each connecting piece 45a is formed with a U-shaped connecting recess 45b whose side surface is elongated and open forward. The left and right connecting pieces 45a, 45a of the second arm front connecting portion 45 are rotatably and slidably engaged with both ends of the connecting shaft 37a of the first arm 31 via the connecting recesses 45b, 45b, respectively.

[0053] FIG. 5(a) shows an enlarged view of the black key 2b and its key support mechanism 6b, while FIG. 5(b) shows them in exploded view. The black key 2b is injection-molded from the same resin material as the white key 2a. It is shorter than the white key 2a, extends a predetermined length in the front-to-back direction, and is hollow and open downward. The front lower end of the black key 2b is provided with a front-side connecting portion 26, which is formed in a manner similar to the front-side connecting portion 22 of the white key 2a. This front-side connecting portion 26 has a connecting recess 26a that is elongated and U-shaped and opens forward. The front-side connecting portion 26 also has an extension 26b at the front end below the connecting recess 26a, which extends a predetermined length forward beyond the front surface of the black key 2b. This extension 26b functions as an upper limit position limiter for the black key 2b. In the following description, the same components of the black key 2b and key support mechanism 6b as those of the white key 2a and key support mechanism 6a are designated by the same reference numerals, and detailed description thereof will be omitted.

[0054] The key support mechanism 6b that supports the black keys 2b is configured in a manner similar to the key support mechanism 6a for white keys described above. Specifically, the arm body 33 of the first arm 31 and the second arm 32 of the key support mechanism 6b are configured to be identical in shape and size to the arm body 33 and second arm 32 of the key support mechanism 6a for white keys. However, the two weights 34, 34 on the left and right of the key support mechanism 6b for black keys have a different rear shape than the weight 34 of the key support mechanism 6a for white keys.

[0055] Next, we will explain the operation of the keys 2 and key support mechanism 6 in the keyboard device 1 configured as above. Figure 6 shows the operation of the white keys 2a and their key support mechanism 6a, and Figure 7 shows the operation of the black keys 2b and their key support mechanism 6b.

[0056] 6(a), when the player presses down on the front end of the white key 2a with his / her finger, the front-key connector 22 of the white key 2a moves downward, causing the first arm 31 to rotate counterclockwise around the first support shaft 18a. Accompanying the rotation of the first arm 31, the front-key connector 45 of the second arm, which engages with the connecting shaft 37a of the first arm 31 via the connecting recess 45b, moves upward. This causes the second arm 32 to rotate clockwise around the second support shaft 19a. Accompanying the rotation of the second arm 32, the rear-key connector 23 connected via the rear-key connector 42 at its rear end is pulled down, causing the rear end of the white key 2a to move downward.

[0057] During the above-described rotation of the first arm 31, as the box portion 35a of the first arm front connecting portion 35 moves downward, the bottom wall of the box portion 35a presses from above against the switch body 3b of the key switch 3 corresponding to the pressed key 2. As a result, the electronic piano detects key press information of the pressed key 2, and a sound is generated from a speaker (not shown) based on the detected key press information.

[0058] As described above, when the white key 2a is pressed down, as the first arm 31 rotates counterclockwise, the weight 34 of the first arm 31 tilts upward at the rear as shown in Figure 6(b), and its rear end abuts against the first arm upper limit stopper 10a from below, thereby preventing further rotation of the first arm 31. Then, when the front end of the white key 2a is pressed down to the lowest position, the front end of the white key 2a abuts against the key lower limit stopper 16b, preventing further depression of the white key 2a.

[0059] When the white key 2a is pressed as described above, it rotates around an imaginary fulcrum P located behind its rear end. The position of this imaginary fulcrum P is set, for example, so that the distance from the front end of the white key 2a is approximately twice the length of the white key 2a itself. As a result, when the front end of the white key 2a is pressed down to the lowest position, the front end of the white key 2a is positioned a predetermined keystroke (e.g., 10 mm) lower, and the rear end of the white key 2a is positioned approximately half the keystroke (e.g., 5 mm) lower, compared to when the key is released as shown in Figure 6(a).

[0060] On the other hand, when the pressed white key 2a is released, the weight of the weight 34 causes the first arm 31 of the key support mechanism 6a to rotate in the opposite direction to that described above, and accordingly, the second arm 32 also rotates in the opposite direction to that described above. As a result, the white key 2a rotates upward around the imaginary fulcrum P. Then, a predetermined portion of the first arm 31 behind the first support shaft 18a abuts against the first arm lower limit stopper 10b from above, and both upper limit position restriction portions 21, 21 of the white key 2a abut against the key upper limit stopper 16a from below, preventing further rotation of the white key 2a and returning it to its original key-released state.

[0061] Furthermore, the operation of the black key 2b when pressed is similar to that of the white key 2a and key support mechanism 6a described above. Specifically, when the front end of the black key 2b is depressed in the key-released state shown in FIG. 7(a), the first arm 31 rotates counterclockwise around the first support shaft 18a, and the second arm 32 rotates clockwise around the second support shaft 19a, causing the black key 2b to rotate around a virtual fulcrum Q at the rear. Similar to the virtual fulcrum P of the white key 2a described above, the position of this virtual fulcrum Q is set so that its distance from the front end of the black key 2b is approximately twice the length of the black key 2 itself. Therefore, when the front end of the black key 2b is depressed to its lowest position, the front end of the black key 2b is positioned a predetermined keystroke lower than in the key-released state shown in FIG. 7(a), and the rear end of the black key 2b is positioned approximately half the keystroke lower.

[0062] On the other hand, when the pressed black key 2b is released, the first arm 31 and the second arm 32 of the key support mechanism 6b rotate in the opposite direction, causing the black key 2b to rotate upward around the virtual fulcrum Q. Then, the extension 26b of the front-key connecting portion 26 of the black key 2b abuts against the upper key stopper 17 from below, preventing further rotation of the black key 2b and returning it to its original released state.

[0063] Next, the main features of the present invention will be described with reference to Figures 8 to 19. The main features of the present invention are that the keyboard device 1 is provided with a let-off function, specifically, by providing a let-off member on one side of the first arm 31 (hammer) and the rib 14 (partition wall) arranged on its side, and an engaging portion that can engage with the let-off member on the other side, and by temporarily engaging the let-off member with the engaging portion while the first arm 31 is rotating in response to a key depression, a let-off feeling is imparted to the touch of the depressed key 2.

[0064] First, with reference to Figures 8 to 15, a first embodiment will be described in which a let-off member 51 is provided on the rib 14 and an engagement portion is provided on the first arm 31. Figure 8 shows a state in which the let-off members 51 are attached to all of the multiple ribs 14 (12 in Figure 8(a)) on the chassis main body 4a of the keyboard chassis 4, with (a) being a plan view and (b) being a side cross-sectional view taken along line BB in (a). As shown in the figure, the let-off member 51 is attached to the rib 14 at a predetermined position diagonally below and rearward of the second support shaft 19a.

[0065] Note that each let-off member 51 has the same basic configuration, but as will be described later, one of the left and right engaging protrusions 54, 55 is located further forward than the other, and in the following description, the let-off member 51 with the right engaging protrusion 55 located forward will be designated as type A and given the reference number 51A, and the let-off member 51 with the left engaging protrusion 54 located forward will be designated as type B and given the reference number 51B. Furthermore, let-off members that do not specifically distinguish between type A and type B will be designated with the reference number 51.

[0066] 9 shows the chassis main body 4a viewed from diagonally below, with the multiple let-off members 51 at the center, and shows the two A-type and B-type let-off members 51A and 51B on the left side removed from their respective ribs 14. Also, Figures 10(a) and 10(b) show the A-type let-off member 51A viewed from diagonally above and below, and Figures 10(c) and 10(d) show the B-type let-off member 51B viewed from diagonally above and below.

[0067] The let-off member 51 is made of an elastic material (for example, a thermoplastic elastomer) and is a molded product having a predetermined shape. As shown in Fig. 10, the let-off member 51 has a mounting portion 52 that extends a predetermined length in the front-rear direction and is formed in a concave shape that opens upward, a block-shaped base 53 provided in the rear half of the bottom surface of the mounting portion 52, and two left and right engaging protrusions 54, 55 provided on the left and right sides of the base 53, respectively, and protruding outward from the left and right side surfaces of the mounting portion 52.

[0068] 11(a) and 11(b) show a front view and a right side view, respectively, of the let-off member 51. As shown in these figures and in FIG. 10, the mounting portion 52 of the let-off member 51 has a mounting hole 52a that penetrates in the vertical direction, immediately in front of the base portion 53. The left and right engaging protrusions 54, 55 of the let-off member 51 are formed symmetrically in front shape, and each has curved surfaces 54a, 55a that curve outward. Furthermore, the portions of each engaging protrusion 54, 55 below the base portion 53 are formed so that the width in the horizontal direction decreases downward.

[0069] 9, a retaining portion 14a and two left and right locking claws 14b, 14b are integrally provided on the chassis main body 4a at predetermined positions on the rib 14 to which the let-off member 51 is attached, for each let-off member 51, to firmly attach the member to the rib 14. The retaining portion 14a protrudes downward by a predetermined length from the underside of the rib 14, and has a widened portion at its lower end that is wider than its upper side and tapered downward. Meanwhile, each locking claw 14b is provided behind the retaining portion 14a, and is formed so that its upper surface protrudes forward at the same height as the upper end of the widened portion of the retaining portion 14a.

[0070] 11(c) and (d) show a state in which the let-off member 51 is attached to the rib 14 by the retaining portions 14a and the locking claws 14b. As shown in the figures, when the let-off member 51 is attached to the rib 14, the attachment portions 52 of the let-off member 51 sandwich the rib 14 from both the left and right sides, the widened portions at the lower ends of the retaining portions 14a of the rib 14 pass through the attachment holes 52a of the attachment portions 52 from above, and the left and right locking claws 14b, 14b behind the retaining portions 14a lock the rear end of the lower surface of the attachment portions 52 from below. In this way, each let-off member 51 is firmly attached to a predetermined position at the lower end of the corresponding rib 14.

[0071] FIG. 12 shows the first arm 31, with (a) being a perspective view and (b) being a right side view. As shown in the figure, the first arm 31 is provided with two left and right engagement portions 39, 39 that temporarily engage with the left and right let-off members 51, 51 when the first arm 31 rotates in response to a key depression. The engagement portions 39, 39 are provided at the upper portions of the left and right sides of the first arm 31, more specifically, at predetermined positions rearward of the bearing portion 36 and the connecting shaft 37a and immediately forward of the weight mounting portion 38. Each engagement portion 39 protrudes laterally and is formed so that its upper surface 39a is slightly inclined rearward in the key-released state. As a result, as will be described later, when the first arm 31 rotates, the engagement portions 39, 39 engage with the engagement protrusions 55, 54 of the left and right let-off members 51, 51 with their upper surfaces 39a horizontal.

[0072] In addition, guide protrusions 40, 40 extending in the vertical direction are provided immediately behind both engagement portions 39, 39, and each guide protrusion 40 faces the arm guide 4b (see Figures 8 and 9) of the chassis main body 4a in close proximity, thereby preventing lateral vibration of the first arm 31 when it rotates.

[0073] FIG. 13 is a plan view centered on the engagement portions 39 of the let-off members 51 and the first arms 31, with the let-off members 51 attached to all of the ribs 14 of the chassis main body 4a and the first arms 31 positioned between every pair of adjacent ribs 14. This figure also shows the key-released state, with each engagement portion 39 of the first arms 31 positioned below the let-off members 51. As shown in the figure, A-type let-off members 51A and B-type let-off members 51B are attached alternately, starting from the left, to the twelve ribs 14 of the chassis main body 4a. This allows the left and right engagement portions 39 of each first arm 31 to engage with the right-side engagement protrusion 55 of the left-side let-off member 51 and the left-side engagement protrusion 54 of the right-side let-off member 51 at the same position in the front-to-rear direction (the up-and-down direction in FIG. 13), i.e., at symmetrical positions.

[0074] Here, the operation of the let-off member 51 caused by the rotation of the first arm 31 accompanying key depression will be described with reference to Figure 14. Figure 14(a) shows the left and right engagement portions 39, 39 of the first arm 31 in the key-released state, and the two left and right let-off members 51, 51 attached to the ribs 14, 14 (not shown in Figure 14) arranged on both the left and right sides of the first arm 31, respectively.

[0075] When a key 2 is pressed down, the first arm 31 corresponding to that key 2 rotates in a predetermined direction, and the left and right engagement portions 39, 39 of the first arm 31 rise and come into contact from below with the right engagement protrusion 55 of the left let-off member 51 and the left engagement protrusion 54 of the right let-off member 51 (FIG. 1(b)). When the key 2 is pressed down further, the first arm 31 also rotates further, and the left and right engagement portions 39, 39 rise while pushing the engagement protrusions 55, 54 of the left and right let-off members 51, 51 aside (FIG. 1(c)), and reach a position higher than the engagement protrusions 55, 54 (FIG. 1(d)). In this way, when the engaging portions 39, 39 of the rotating first arm 31 pass from bottom to top between the engaging protrusions 55, 54 of the left and right let-off members 51, 51, a reaction force from the engaging protrusions 55, 54 acts on the engaging portions 39, 39, causing a rotational resistance to act on the first arm 31. This imparts a let-off feel to the touch of the key 2 corresponding to that first arm 31, i.e., the key 2 supported by the key support mechanism 6 having that first arm 31.

[0076] Thereafter, when the key 2 is released from the depressed state, the key 2 rotates upward and the first arm 31 rotates in the opposite direction, causing the left and right engagement portions 39, 39 of the first arm 31 to descend and come into contact with the engagement protrusions 55, 54 of the left and right let-off members 51, 51 from above (FIG. 1(e)). Then, as the key 2 rotates further upward, the first arm 31 also rotates further, causing the left and right engagement portions 39, 39 to descend while pushing the engagement protrusions 55, 54 of the left and right let-off members 51, 51 aside (FIG. 1(f)), returning to the key-released state described above (FIG. 1(a)). In this way, when the engaging portions 39, 39 of the first arm 31 pass from top to bottom between the engaging protrusions 55, 54 of the left and right let-off members 51, 51, the engaging protrusions 55, 54 are structurally prone to bending inward, so the rotational resistance acting on the first arm 31 is much smaller than when the engaging protrusions 39, 39 pass from bottom to top as described above. Therefore, when the depressed key 2 is released, the aforementioned let-off feeling does not occur.

[0077] 15 shows a unit component 57 in which multiple (for example, 12 pieces, only six are shown in FIG. 15) let-off members 51 are integrally molded. This unit component 57 is in the state before each let-off member 51 is attached to the multiple ribs 14 of the chassis main body 4a when assembling the keyboard device 1.

[0078] In the unit component 57, a portion of the front end surface of the bottom wall of the mounting portion 52 of each let-off member 51 is formed to be continuous with a connecting portion 58 that extends in a strip-like shape for a predetermined length. Furthermore, in this unit component 57, each let-off member 51 is arranged to correspond to the rib 14 to which it is to be attached. That is, the left-right spacing between two adjacent ribs 14, 14 in the chassis main body 4a varies depending on the key 2 to be placed between those ribs 14, 14. Meanwhile, the shape and size of the first arm 31 are the same for all keys 2. Therefore, as described above, each let-off member 51 has the same basic configuration, but the left-right width dimensions of the left and right engaging protrusions 54, 55 are set according to the rib 14 to which it is to be attached. Therefore, in the unit component 57, each let-off member 51 is arranged in order along the length of the connecting portion 58 according to the arrangement of the rib 14 to which it is to be attached.

[0079] Furthermore, as described above, each let-off member 51 is set according to the rib 14 to which it should be attached, and therefore, if the let-off member 51 is not properly attached to the corresponding rib 14, a good let-off feeling may not be obtained. Therefore, even if the let-off member 51 is removed from the rib 14 during maintenance or the like, each let-off member 51 is given a code corresponding to the rib 14 to which it should be attached (including the code name of the key 2 on either the left or right side of that rib 14, etc.) so that it is easy to know to which rib 14 the removed let-off member 51 should be attached. For example, these codes are given to the front side of the attachment hole 52a on the bottom surface of the attachment portion 52 of each let-off member 51 when the unit part 57 is molded.

[0080] Furthermore, the connecting portions 58 of the unit parts 57 described above can be easily detached manually from the respective let-off members 51. Therefore, when assembling the keyboard device 1, after each let-off member 51 of the unit part 57 has been attached to the corresponding rib 14, the connecting portions 58 can be easily detached from each let-off member 51 by pulling them outward from the chassis main body 4a.

[0081] As described above, with the keyboard device 1 equipped with the let-off member 51 of the first embodiment, when the first arm 31 rotates in response to a key 2 being pressed, the engagement portions 39 of the first arm 31 temporarily engage with the left and right let-off members 51, applying rotational resistance to the rotating first arm 31. This temporarily increases the touch weight of the key 2, thereby imparting a let-off feel to the touch of the key 2 similar to that of an acoustic piano.

[0082] Furthermore, because the let-off member 51 is attached to the rib 14 on the side of the first arm 31, there is no need to ensure a large space between it and the key 2, as has been the case in the past. This allows the keyboard device 1 with let-off function to be constructed compactly. Additionally, by positioning the let-off member 51 and the engagement parts 39, 39 of the first arm 31 in the aforementioned positional relationship, the start timing and duration of the let-off can be set relatively easily, allowing for greater freedom in setting these.

[0083] Furthermore, since the left and right engaging protrusions 54, 55 of the let-off member 51 are arranged offset from each other in the front-to-rear direction, even when, for example, two adjacent keys 2 are pressed simultaneously or successively and the first arms 31 corresponding to those keys 2 respectively engage with the two engaging protrusions 54, 55 of a single let-off member 51, it is possible to prevent interference such as collision between the engaging protrusions 54, 55. This allows for a stable let-off feel even when two adjacent keys 2 are pressed.

[0084] Furthermore, the let-off members 51 are detachably attached to the ribs 14, and before the keyboard device 1 is assembled, multiple let-off members 51 are integrally molded into a unit component 57. Furthermore, each let-off member 51 is assigned a symbol corresponding to the rib 14 to which it should be attached, making it easy to attach or replace the let-off members 51 when assembling or maintaining the keyboard device 1.

[0085] 16 to 19, a second embodiment will be described in which, contrary to the first embodiment described above, the let-off member is provided on the first arm and the engagement portion is provided on the rib 14. Note that the first arm 31A shown in FIG. 16 has a different shape from the first arm 31 described above, but the basic configuration is the same, so the same components as those in the first arm 31 will be denoted by the same reference numerals.

[0086] 16, a let-off member 61 is attached to a predetermined position of the first arm 31A. Specifically, the let-off member 61 is attached to a predetermined position on the first arm 31A, rearward of the bearing portion 36 and the connecting shaft 37a and immediately forward of the weight mounting portion 38.

[0087] 17 shows an enlarged view of the let-off member 61, with (a) being a perspective view and (b) being a front view. As shown in the figure, the let-off member 61 is made of an elastic material (e.g., a thermoplastic elastomer) and is a molded product having a predetermined bilaterally symmetrical shape. Specifically, the let-off member 61 has a fixing portion 62 for fixing the let-off member 61 to the first arm 31A, left and right wall portions 63 and 64 connected to the fixing portion 62, and left and right inclined pieces 65 and 66 protruding obliquely upward from the outer surfaces of the fixing portion 62 and the wall portions.

[0088] The fixing portion 62 of the let-off member 61 is formed to complement the shape (T-shape) of the portion to which the first arm 31A is attached (hereinafter referred to as the "attachment portion 33a"), with both left and right ends curved downward. Furthermore, left and right side walls 63 and 64 connected to the lower portion of the fixing portion 62 hang down parallel to each other for a predetermined length, spaced apart from each other by a distance approximately equal to the left-right thickness of the attachment portion 33a, and closely contact the left and right side surfaces of the attachment portion 33a, respectively. Furthermore, left and right inclined pieces 65 and 66 protrude diagonally upward for a predetermined length at a predetermined angle (e.g., 45 degrees) from the lower ends of the corresponding left and right side walls 63 and 64. Note that both left and right inclined pieces 65 and 66 protrude outward beyond the left and right end faces of the fixing portion 62.

[0089] Figure 18 shows two adjacent ribs 14, 14 and a let-off member 61 disposed between them and attached to the attachment portion 33a of the first arm 31A. On the opposing surfaces of the two ribs 14, 14, i.e., the surfaces on the first arm 31A side, engaging portions 68, 69 protrude a predetermined length, extend in the front-to-rear direction (the front-to-back direction in Figure 18), and face each other, and are provided integrally with the ribs 14. These engaging portions 68, 69 are provided at a predetermined height through which the let-off member 61 passes when the first arm 31A rotates in response to a key depression.

[0090] Here, the operation of the let-off member 61 caused by the rotation of the first arm 31A in response to a key press will be described with reference to Figure 19. Figure 19(a) is a diagram similar to Figure 18 described above, and shows the let-off member 61 attached to the attachment part 33a of the first arm 31A in the key-released state.

[0091] When a key 2 is pressed down, the first arm 31A corresponding to that key 2 rotates in a predetermined direction, causing the let-off member 61 of the first arm 31A to rise, and the tips of the left and right inclined pieces 65, 66 come into contact with the engagement portions 68, 69 of the left and right ribs 14 from below (FIG. 1(b)). When the key 2 is pressed down further, the first arm 31A also rotates further, pushing up the let-off member 61. In this case, the left and right inclined pieces 65, 66 of the let-off member 61 press against the engagement portions 68, 69 of the rib 14 from below, and the reaction force causes them to deform (FIG. 1(c)), climbing over the engagement portions 68, 69 and reaching a position higher than the engagement portions 68, 69 (FIG. 1(d)). In this way, when the let-off member 61 of the rotating first arm 31A passes from bottom to top between the left and right engagement portions 68, 69, a reaction force from the engagement portions 68, 69 acts on the let-off member 61, causing a rotation resistance to act on the first arm 31A. As a result, a let-off feel is imparted to the touch of the key 2 corresponding to the first arm 31A, just like in the first embodiment described above.

[0092] When the key 2 is subsequently released from the depressed state, the key 2 rotates upward, and the first arm 31A rotates in the opposite direction. Accordingly, the let-off member 61 descends, and the tips of the left and right inclined pieces 65, 66 come into contact with the engagement portions 68, 69 of the left and right ribs 14 from above (FIG. 1(e)). As the key 2 rotates further upward, the first arm 31A also rotates further, and the left and right inclined pieces 65, 66 deform inward, passing through the engagement portions 68, 69 and descending (FIG. 1(f)), returning to the key-released state described above (FIG. 1(a)). As described above, when the inclined pieces 65, 66 of the let-off member 61 of the first arm 31A pass from top to bottom between the left and right engagement portions 68, 69, the inclined pieces 65, 66 are structurally prone to bending inward, and therefore the rotational resistance acting on the first arm 31A is extremely small compared to when the inclined pieces 65, 66 pass from bottom to top. Therefore, as with the first embodiment described above, there is no let-off feeling when the pressed key 2 is released.

[0093] As described above, with the keyboard device 1 equipped with the let-off member 61 of the second embodiment, when the first arm 31 rotates in response to the depression of a key 2, the left and right inclined pieces 65, 66 of the let-off member 61 temporarily engage with the engagement portions 68, 69 of the left and right ribs 14, 14, and rotation resistance acts on the rotating first arm 31A. This temporarily increases the touch weight of the key 2, imparting a let-off feel similar to that of an acoustic piano to the touch of the key 2. Furthermore, as with the first embodiment described above, the keyboard device 1 with the let-off function can be configured compactly, and the degree of freedom in setting the start timing and duration of the let-off can be increased.

[0094] The present invention is not limited to the above-described embodiment, but can be implemented in various ways. For example, in the above-described embodiment, the present invention is applied to a keyboard device 1 in which a depressed key 2 rotates around virtual fulcrums P and Q at the rear, but the present invention is not limited to this, and can of course also be applied to a general keyboard device in which the key rotates around its own rear end and does not have a second arm 32.

[0095] Furthermore, although the let-off members 51 in the first embodiment are attached to all of the adjacent ribs 14, 14, it is also possible to attach the let-off members 51 to only one of the adjacent ribs 14, 14. Furthermore, although the left and right engagement portions 39, 39 of the first arm 31 are provided at the upper part of the side surface of the first arm 31 in the first embodiment, they can also be provided at other positions on the side surface (for example, the center or the lower part). Furthermore, a let-off member having a similar configuration to the let-off member 51 in the first embodiment can be attached to an appropriate portion of the first arm 31A (for example, a portion below the attachment portion 33a) instead of the let-off member 61 in the second embodiment.

[0096] Furthermore, the detailed configurations of the keyboard device 1, let-off members 51, 61, engagement portion 39 of the first arm 31, and engagement portions 68, 69 of the rib 14 shown in the embodiment are merely examples and can be modified as appropriate within the scope of the spirit of the present invention. [Explanation of symbols]

[0097] 1 Keyboard device 2 keys 2a white key 2b black key 4-key chassis 4a Chassis body 6 Key support mechanism 14 Rib (partition wall) 14a Stopper 14b Locking claw 18a 1st spindle 19a 2nd spindle 31 First Arm (Hammer) 32 Second Arm 33 Arm body of first arm 33a Mounting location 36 Bearing section 37a Connecting shaft 38 Weight attachment part 39 Engagement part 51 Let-off member 51A A-tap let-off member 51B B-type let-off member 52 Mounting part 52a Mounting hole 53 Base 54 Left side engagement protrusion 54a: Curved surface of engaging protrusion 55 Right side engagement protrusion 55a Curved surface of engaging protrusion 57 Unit parts made of multiple let-off components 58 Connection part 61 Let-off member 62 Fixed part 63 Left wall 64 Right wall 65 Left inclined piece 66 Right inclined piece 68 Left side engagement part 69 Right side engagement part

Claims

1. A keyboard device for a keyboard instrument having a let-off function that gives a let-off feeling similar to that of an acoustic piano, a keyboard chassis having a plurality of partition walls each extending in the front-rear direction and arranged at predetermined intervals in the left-right direction; a plurality of keys each extending in the front-rear direction and disposed at positions corresponding to the spaces between the adjacent partition walls on the upper portion of the keyboard chassis; a plurality of hammers, each extending in the front-rear direction and rotatably supported via a predetermined bearing on a hammer spindle provided on the keyboard chassis below the corresponding key and extending in the left-right direction between the adjacent partition walls, so that when the key is pressed, the hammers rotate in conjunction with the corresponding key; Equipped with a let-off member is attached to one of the two adjacent partition walls and the hammer disposed between the two partition walls; A keyboard device for a keyboard instrument is characterized in that the other of the two adjacent partition walls and the hammer arranged between the two partition walls is provided with an engagement portion that temporarily engages in a state of contact with the let-off member while the hammer rotates in response to a key being pressed, thereby applying rotational resistance to the hammer and imparting a let-off feel to the touch of the pressed key.

2. the let-off members are made of an elastic material and are attached to the two adjacent partition walls, respectively; 2. The keyboard device for a keyboard instrument according to claim 1, wherein the engagement portions are provided on the left and right sides of the hammer, respectively, and are configured to be able to engage with let-off members attached to the two partition walls during the rotation of the hammer in response to key depression.

3. The let-off member is a mounting portion that is attached to a predetermined position of the partition wall from below; an engaging protrusion provided on the underside of the mounting portion and having a curved surface that curves convexly toward the hammer to be engaged; 3. The keyboard device for a keyboard instrument according to claim 2, further comprising:

4. The mounting portion of the let-off member is formed in a concave shape that opens upward and can sandwich the partition wall from both the left and right sides, 4. The keyboard device for a keyboard instrument according to claim 3, wherein the partition wall has a retaining portion that penetrates the mounting portion from above and holds the mounting portion in a retaining state.

5. 5. The keyboard device for a keyboard instrument according to claim 4, wherein the keyboard chassis is provided with a locking claw that locks the mounting portion of the let-off member attached to the partition wall from below.

6. 6. A keyboard device for a keyboard instrument according to claim 3, wherein the engagement protrusions are arranged at a distance from each other in the left-right direction and are configured as two engagement protrusions that can respectively engage with the two hammers arranged on the left and right sides of the partition wall to which the let-off member is attached.

7. 7. The keyboard device for a keyboard instrument according to claim 6, wherein the two engaging projections are arranged offset from each other in the front-rear direction.

8. 8. A keyboard device for a keyboard instrument as described in any one of claims 3 to 7, characterized in that the let-off member is configured so that the resistance force acting on the hammer when the engagement portion of the hammer engages with the engagement convex portion from above is smaller than the resistance force acting on the hammer when the engagement portion engages with the engagement convex portion from below.

9. The plurality of let-off members are arranged in a line corresponding to the plurality of partition walls to be attached, and are prepared as unit parts integrally molded in a state in which they are connected to a band-shaped connecting portion via each of the attachment portions, 9. A keyboard device for a keyboard instrument according to any one of claims 3 to 8, characterized in that the unit parts are configured such that, when assembling the keyboard device, the plurality of let-off members are attached to the plurality of partition walls, respectively, and then the connecting portions are detached from each of the plurality of let-off members.

10. 10. The keyboard device for a keyboard instrument according to claim 9, wherein each of the plurality of let-off members is provided with a symbol corresponding to the partition wall to which it is to be attached.

11. the let-off member is made of an elastic material, attached to the hammer, and formed so as to protrude outward from the left and right side surfaces of the hammer, 2. The keyboard device for a keyboard instrument according to claim 1, wherein the engaging portions are provided on opposing surfaces of two adjacent partition walls.

12. The engaging portions are configured by two engaging portions formed so as to protrude from predetermined positions on the opposing surfaces of the two adjacent partition walls, The let-off member is a fixing part fixed to an upper part of the hammer; Two side walls, left and right, connected to this fixed part and hanging down along the left and right sides of the hammer, Two inclined pieces, one on the left and one on the right, protruding obliquely upward from the two left and right side walls by a predetermined length, 12. The keyboard device for a keyboard instrument according to claim 11, further comprising:

Images