Keyboard device for keyboard instruments

Abstract

To provide a keyboard device of a keyboard instrument, which has a comparatively simple structure, can adjust a height and an amount, which a hammer corresponding to each key contacts a stopper, and can obtain satisfactory touch feeling of each key.SOLUTION: A keyboard device of a keyboard instrument includes: stopper rails 53 and 55 provided at the bottom of a keyboard chassis 4; and cushions 54 and 56 which extend in a longitudinal direction, whose cross sections are formed to be constant for the whole in a length direction, are attached in a state in which the cushions are placed on the stopper rails 53 and 55 and on which prescribed portions of a hammer 31 abut from above. In the stopper rails 53 and 55, black key portions 53b and 55b being portions below the cushions 54 and 56 on which the hammer 31 corresponding to black keys 2b abuts are configured in a notched state or a prescribed low state to white key portions 53a and 55a being portions below the cushions 54 and 56 on which the hammer 31 corresponding to white keys 2a abuts.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, which is equipped with hammers that rotate in conjunction with the depression of a key. [Background technology]

[0002] A keyboard device of this type is known, for example, from Patent Document 1. In this keyboard device, a hammer is rotatably mounted below each key extending in the front-rear direction. When the key is released, each hammer extends in the front-rear direction with a downward tilt toward the rear, and its rear end abuts against a stopper from above. The stopper is composed of a stopper rail extending horizontally in the left-right direction and a buffer material on the top surface of the stopper rail, the cross section of which is formed into a constant rectangular shape along the entire length.

[0003] In a keyboard device having such a stopper, when a key is pressed, the hammer corresponding to that key rotates in a predetermined direction, and the rear end of the hammer moves above the stopper. When the key is released, the hammer rotates in the opposite direction, and the rear end of the hammer abuts against the stopper from above. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-10374 Summary of the Invention [Problem to be solved by the invention]

[0005] Because the stopper described above is shared by both the white key hammers and the black key hammers, the following problem occurs: If the white key hammers are heavier than the black key hammers, when the white key hammers hit the buffer, they sink in more than the black key hammers and may bounce more than the black key hammers before coming to a complete stop. In this case, the touch of the white keys and the touch of the black keys will be different, making it difficult to adjust the touch of both the white keys and the black keys to the optimum.

[0006] Furthermore, when the same hammer is used for both white and black keys, if the hammers for white and black keys have different postures when the key is released or different heights relative to the stoppers, it is necessary to adjust the shape of the weight attached to the hammer or the height of the part of the cushioning material that the hammer contacts, which increases manufacturing costs.

[0007] The present invention has been made to solve the above-mentioned problems, and aims to provide a keyboard device for a keyboard instrument that has a relatively simple structure and allows adjustment of the height and amount at which the hammer corresponding to each key abuts against the stopper, thereby providing a good touch feeling for each key. [Means for solving the problem]

[0008] In order to achieve the above object, the invention of claim 1 comprises a keyboard chassis, a plurality of keys consisting of white keys and black keys, each extending in the front-rear direction and arranged in a row in the left-right direction on top of the keyboard chassis, a plurality of hammers each extending in the front-rear direction and provided corresponding to each of the plurality of keys, rotatably supported on the keyboard chassis below the keys via hammer spindles and arranged in a row in the left-right direction, and rotating up and down in conjunction with a pressed key, a stopper rail formed in a plate shape extending in the left-right direction and provided on the underside of the keyboard chassis, and a stopper rail extending in the left-right direction and having a constant cross section throughout its entire length. and a cushion that is formed on the stopper rail and mounted while being placed on it, and that is arranged so that predetermined portions of the multiple hammers are placed on or facing each other in the key-released state, and that the predetermined portions of the hammers abut from above when the hammers that have rotated upward upon key depression return to their original positions upon key release.The stopper rail is characterized in that the first key type portion, which is the portion below the cushion that the hammers corresponding to a first key type, one of the white keys and the black keys, abut on, is cut out or is lower by a predetermined height than the second key type portion, which is the portion below the cushion that the hammers corresponding to the other of the white keys and the black keys, abut on.

[0009] According to this configuration, a plate-shaped stopper rail extending laterally is provided below the keyboard chassis, and a cushion with a uniform cross section is mounted on the stopper rail. Predetermined portions of hammers corresponding to the white and black keys abut against the cushion from above. The stopper rail is configured such that a first key type portion, which is a portion below the cushion that a hammer corresponding to a first key type (one of the white and black keys) abuts against, is cut out or is lower by a predetermined height than a second key type portion, which is a portion below the cushion that a hammer corresponding to the other of the white and black keys (a second key type). As a result, even though the cushion mounted on the stopper rail has a uniform cross section, the portion of the cushion corresponding to the first key type portion of the stopper rail has a lower upper surface or a greater hammer abutment amount than the portion of the cushion corresponding to the second key type portion of the stopper rail. As described above, by using a relatively simple configuration such as cutting out the first key type portion of the stopper rail or making it lower than the second key type portion, the height and amount at which the hammer corresponding to each key contacts the cushion can be adjusted, thereby providing a good touch feeling for each key.

[0010] The invention of claim 2 is characterized in that, in the keyboard device of the keyboard instrument described in claim 1, the first key type portion is configured to be lower by a predetermined height than the second key type portion, and the stopper rail is formed so that the upper surface of the first key type portion is inclined downward toward the front and outward in the front-to-back direction.

[0011] According to this configuration, the first key type portion of the stopper rail is lower by a predetermined height than the second key type portion, and the upper surface of the first key type portion is formed to be inclined in the front-to-rear direction, so when attaching a cushion to the stopper rail, a cushion with a constant cross section can be attached relatively easily and stably by gluing or the like to the upper surface of the first key type portion as well as the upper surface of the second key type portion.In addition, because the upper surface of the first key type portion of the stopper rail is formed to be inclined downward in the front and outward in the front-to-rear direction, processing of the first key type portion of the stopper rail can be carried out relatively easily and stably.

[0012] The invention according to claim 3 is characterized in that in the keyboard device for a keyboard instrument according to claim 1 or 2, the first key type is black keys and the second key type is white keys.

[0013] With this configuration, by designating the first key type as black keys and the second key type as white keys, the black key portion of the stopper rail below the cushion with which the black key hammers contact is cut out or is lowered by a predetermined height than the white key portion below the cushion with which the white key hammers contact. This makes it possible to obtain a good touch for both white and black keys by, for example, configuring the stopper rail and cushion to optimally fit the white key hammers and adjusting the cushion portion of the stopper rail corresponding to the black key portion in the vertical direction. [Brief explanation of the drawings]

[0014] [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 perspective view showing the keyboard device as viewed from below, and (b) is a perspective view showing the front and rear first arm stoppers as viewed from above. [Figure 9] FIG. 10 is a perspective view showing the front and rear first arm stoppers with the stopper rails and cushions separated from each other. [Figure 10] FIG. 10 is a perspective view showing a modified example of the stopper rail in the rear first arm stopper. DETAILED DESCRIPTION OF THE INVENTION

[0015] 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.

[0016] 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.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] 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 includes a flat section 12a extending laterally and a plurality of black key guides 12b arranged vertically on the flat section 12a and spaced apart appropriately in the left-right direction. Each black key guide 12b is inserted into each black key 2b from below to prevent the key from swaying laterally. The front of the chassis intermediate section 12 includes a first arm support section 18 that supports the first arm 31 of the key support mechanism 6. The first arm support section 18 includes a plurality of first support shafts 18a extending laterally between adjacent ribs 14. The first arms 31 are swingably supported by these first support shafts 18a. Furthermore, a second arm support section 19 that supports a second arm 32 of the key support mechanism 6 is provided at the rear of the chassis intermediate section 12. This second arm support section 19 has a plurality of second support shafts 19a that are provided between adjacent ribs 14, 14 and extend in the left-right direction. The plurality of second support shafts 19a are arranged on the same axis that extends in the left-right direction, at a position rearward and higher than the first support shaft 18a, and the second arm 32 is supported by these second support shafts 19a so that it can swing freely. Note that a first arm lower limit stopper 10b that extends 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) that is provided below the chassis intermediate section 12.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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 position restrictor 21, for connecting to the first arm 31 of the key support mechanism 6a. This front-key connecting portion 22 has a connecting recess 22a with an elongated hole-like side and a U-shaped opening toward the front. A buffer member 20 is attached to the 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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).

[0042] 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.

[0043] 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.

[0044] 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.

[0045] Next, the main features of the present invention will be described with reference to Figures 8 to 10. The main feature of the present invention is that in first arm stoppers 51, 52, which are provided at the bottom of keyboard chassis 4 and against which first arms 31 (hammers) of each key 2 abut from above, the locations of stopper rails 53, 55 on which cushions 54, 56 are placed are configured to be different for the white key locations and the black key locations.

[0046] As shown in Figure 8(a), the keyboard device 1 of the present invention is provided with a front first arm stopper (hereinafter referred to as the "front stopper") 51 and a rear first arm stopper (hereinafter referred to as the "rear stopper") 52 at a predetermined distance from each other in the front-to-rear direction on the bottom of the keyboard chassis 4. The front stopper 51 is made up of a front stopper rail 53 corresponding to the middle rail 8, and a front cushion 54 provided at the rear end of the upper surface of the front stopper rail 53. Meanwhile, the rear stopper 52 is made up of a rear stopper rail 55 corresponding to the rear rail 9, and a rear cushion 56 provided at the front end of the upper surface of the rear stopper rail 55.

[0047] 9 shows the front stopper 51 with the front stopper rail 53 and the front cushion 54 separated, and also shows the rear stopper 52 with the rear stopper rail 55 and the rear cushion 56 separated. As shown in the figure, the front stopper rail 53 and the rear stopper rail 55 are made by pressing a metal plate of a predetermined shape, and extend in the left-right direction as a whole (the depth direction in FIG. 9), and are formed so as to have a step between their front and rear half portions (the left half portion and the right half portion in FIG. 9).

[0048] At the rear end (right end in FIG. 9) of the front stopper rail 53, there are provided a plurality (five in FIG. 9) of white key portions 53a (second key type portions) and black key portions 53b (first key type portions), which are portions located below the front cushion 54 and against which the first arms 31 corresponding to the white keys 2a and black keys 2b respectively abut from above. These white key portions 53a are each formed as a flat plate, and their upper surfaces are formed flush. On the other hand, each black key portion 53b penetrates vertically and has a rectangular notch cut out in plan view.

[0049] Meanwhile, a front end portion (left end portion in FIG. 9 ) of the rear stopper rail 55 is provided with a plurality of white key regions 55a (second key type regions) and black key regions 55b (first key type regions) that are formed similarly to the white key regions 53a and black key regions 53b of the front stopper rail 53. That is, a plurality of (five in FIG. 9 ) white key regions 55a and black key regions 55b are alternately provided along the left-right direction of the rear stopper rail 55 at the front end portion of the rear stopper rail 55, and are located below the rear cushion 56 against which the first arms 31 corresponding to the white keys 2a and the black keys 2b respectively abut from above. Each white key region 55a is formed in a flat plate shape, while each black key region 55b is formed with a rectangular notch that penetrates vertically.

[0050] Both the front cushion 54 and the rear cushion 56 are made of an elastic material such as urethane, extend a predetermined length in the left-right direction, and are formed with a constant rectangular cross section over the entire length.

[0051] The front cushion 54 is placed on the rear end of the upper surface of the front stopper rail 53 and is attached to the front stopper rail 53 with the front cushion 54 adhered to each of the white key portions 53a. As a result, the portions of the front cushion 54 corresponding to each white key portion 53a become white key contact portions 54a with which predetermined front portions of the white key first arms 31 come into contact, and the portions of the front cushion 54 corresponding to each black key portion 53b become black key contact portions 54b (the portions shaded in FIGS. 8(b) and 9) with which predetermined front portions of the black key first arms 31 come into contact.

[0052] Meanwhile, the rear cushion 56 is placed on the front end of the upper surface of the rear stopper rail 55, and is attached to the rear stopper rail 55 with the rear cushion 56 adhered onto each of the white key portions 55a. As a result, the portions of the rear cushion 56 corresponding to each of the white key portions 55a become white key contact portions 56a with which predetermined rear portions of the white key first arms 31 come into contact, and the portions of the rear cushion 56 corresponding to each of the black key portions 55b become black key contact portions 56b (the portions shaded in FIGS. 8(b) and 9) with which predetermined rear portions of the black key first arms 31 come into contact.

[0053] In the keyboard device 1 equipped with the front stopper 51 and rear stopper 52 configured as described above, during manufacturing, for example, after the cushions 54, 56 are attached to the stopper rails 53, 55, the black key contact portions 54b, 56b of the cushions 54, 56 are molded so that they are slightly pressed down. This causes the upper surfaces of the black key contact portions 54b, 56b of the cushions 54, 56 to be lower than the white key contact portions 54a, 56a. Furthermore, because the black key portions 53b, 55b of the stopper rails 53, 55 are cut out, when the black key first arm 31 comes into contact with the black key contact portions 54b, 56b of the cushions 54, 56, the amount of contact is large.

[0054] As described above, according to this embodiment, the height and amount at which the first arm 31 corresponding to the black key 2b abuts against the cushions 54, 56 can be adjusted with a relatively simple configuration, namely, by cutting out the black key portions 53b, 55b of the stopper rails 53, 55. This makes it possible to obtain a good touch feeling for both the white key 2a and the black key 2b by configuring the stopper rails 53, 55 and the cushions 54, 56 to optimally match the first arm 31 for the white keys and adjusting the black key abutment portions 54b, 56b of the cushions 54, 56 in the vertical direction.

[0055] FIG. 10 shows a modified rear stopper rail 58 of the rear stopper 52. As shown in the figure, this rear stopper rail 58 differs from the aforementioned rear stopper rail 55 only in the black key portion 58b. Specifically, the black key portion 55b of the aforementioned rear stopper rail 55 is cut out to penetrate vertically, whereas the black key portion 58b of the modified rear stopper rail 58 is one step lower than the white key portion 58a and is formed to slope downward toward the front (to the left in FIG. 10). Although not shown, the black key portion 53b of the aforementioned front stopper rail 53 may also be formed to be one step lower than the white key portion 53a and to slope downward toward the rear (to the right in FIG. 9), similar to the rear stopper rail 58.

[0056] Rear stopper rail 58 having black key portion 58b formed as described above not only provides the same advantages as rear stopper rail 55 described above, but also the following advantage. That is, when attaching rear cushion 56 to rear stopper rail 58, rear cushion 56 can be attached relatively easily and stably by adhesive to the upper surface of black key portion 58b as well as the upper surface of white key portion 58a. Furthermore, because the upper surface of black key portion 58b of rear stopper rail 58 is formed to slope downward toward the front, processing of black key portion 58b on rear stopper rail 58 can be performed relatively easily and stably.

[0057] The present invention is not limited to the above-described embodiment and can be embodied in various forms. For example, in the above-described embodiment, the white key portions 53a, 55a of the front stopper rail 53 and the rear stopper rails 55, 58 are formed flat, and the black key portions 53b, 55b are formed with cutouts, or the black key portion 58b of the rear stopper rail 58 in the modified example is formed lower by a predetermined height, but it is also possible to reverse the shapes of the white key portions and the black key portions.

[0058] In addition, in the embodiment, the present invention has been described as being 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 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. Furthermore, the detailed configurations of the stopper rail 53 and cushion 54 of the front stopper 51 and the stopper rail 55 and cushion 56 of the rear stopper 52 shown in the embodiment are merely examples and can be modified as appropriate within the spirit and scope of the present invention. [Explanation of symbols]

[0059] 1 Keyboard device 2 keys 2a white key 2b black key 4-key chassis 6 Key support mechanism 7 Front rail 8 Middle Rail 9 Rear rail 31 First Arm (Hammer) 32 Second Arm 51 Front first arm stopper 52 Rear first arm stopper 53 Front stopper rail 53a White key part (second key type part) 53b Black key part (1st key type part) 54 Front cushion 54a White key contact part 54b Black key contact part 55 Rear stopper rail 55a White key part 55b Black key part 56 Rear cushion 56a White key contact part 56b Black key contact part 58 Rear stopper rail 58a White key part 58b Black key part Virtual fulcrum of P white key Q Virtual fulcrum of black key

Claims

1. Keyboard chassis and a plurality of keys, each extending in the front-rear direction and arranged in a left-right direction on the upper part of the keyboard chassis, the keys being composed of white keys and black keys; a plurality of hammers, each extending in the front-rear direction and corresponding to each of the plurality of keys, rotatably supported by the keyboard chassis via hammer support shafts below the keys and arranged in a line in the left-right direction, and which rotate up and down in conjunction with the pressed keys; a stopper rail formed in a plate shape extending in the left-right direction and provided on the underside of the keyboard chassis; a cushion that extends in the left-right direction and has a constant cross section throughout its length, that is mounted on the stopper rail, that is positioned so that predetermined portions of the hammers are placed on or face each other when the key is released, and that the predetermined portions of the hammers come into contact with from above when the hammers rotate upward in response to key depression and return to their original positions in response to key release; Equipped with a first key type portion of the stopper rail, which is a portion below the cushion with which the hammer corresponding to a first key type of one of the white keys and the black keys comes into contact, is cut out or is lower by a predetermined height than a second key type portion of the stopper rail, which is a portion below the cushion with which the hammer corresponding to the other of the white keys and the black keys comes into contact,

2. 2. The keyboard device for a keyboard instrument according to claim 1, wherein the first key type portion is configured to be lower by a predetermined height than the second key type portion, and the stopper rail is formed so that the upper surface of the first key type portion is inclined downward toward the front and outward in the front-to-back direction.

3. 3. The keyboard device for a keyboard instrument according to claim 1, wherein the first key type is a black key and the second key type is a white key.

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