Keyboard device of a keyboard instrument

Abstract

To provide a keyboard device for a keyboard musical instrument capable of securing the stable keyboard touch by sufficiently suppressing variations of the frictional resistance acting on a hammer during rotation of the hammer.SOLUTION: A keyboard device 1 of the present invention includes: a keyboard chassis 4 (chassis), rotatable keys 2 extending in the front-rear direction; and first arms 31 (hammers) extending in the front-rear direction, rotatably supported by the key board chassis 4, connected to the keys 2 and rotating in conjunction with the depressed keys 2. One of the key 2 and the first arm 31 has a cylindrical connecting shaft 135b and a cylindrical elastic member 120 attached to an outer side of the connecting shaft 135b is further provided. The other of the key 2 and the first arm 31 has a connecting recessed part 122a in which a side surface shape is opened outward in a long hole shape. By fitting the connecting recessed part 122a into the elastic member 120, the connecting recessed part is rotatably and slidably connected to one of the key 2 and the first arm 31.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 provided with a hammer that rotates in conjunction with a key that has been pressed down.

Background Art

[0002] As a conventional keyboard device of this type, for example, the one disclosed in Patent Document 1 is known. In this keyboard device, the key and the hammer (mass body) extend in the front-rear direction, and the key is rotatably supported at the rear end, and the hammer is rotatably supported at the front end. The hammer is connected to the key as follows. First, a hollow hanging piece for driving is integrally provided at the front part of the key, and an elastic member made of rubber or the like is inserted into a mounting hole formed in the lower wall of the hanging piece while being compressed, and is attached in a state where it cannot come off. The elastic member has upper and lower contact surfaces. These upper and lower contact surfaces are gently curved convexly upward and downward, respectively, and are not formed concentrically as a whole of both contact surfaces.

[0003] On the other hand, a connecting recess is formed at the front end of the hammer. This connecting recess is open forward and extends rearward, and its upper and lower receiving surfaces (inner wall surfaces) are parallel to each other, and the distance between both receiving surfaces is substantially equal to the distance between the upper and lower contact surfaces of the elastic member. From the above configuration, when the elastic member of the key is engaged with the connecting recess of the hammer from the front, the hammer is rotatably and slidably connected to the key in a state where the upper and lower contact surfaces of the elastic member are in contact with (sandwiched between) the upper and lower receiving surfaces of the hammer.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] As described above, in the conventional keyboard device, the upper and lower contact surfaces of the elastic member with which the connecting recess of the hammer engages are gently curved and not formed concentrically. Therefore, as the hammer rotates, as the degree of compression of the elastic member changes, the contact pressure between the connecting recess and the elastic member changes, and the greater the rotation of the hammer progresses, the greater the contact pressure becomes. As a result, during the rotation of the hammer, there is a drawback that the frictional resistance and operating load of the hammer fluctuate, and the keyboard touch becomes unstable.

[0006] In addition, since the elastic member has the above-described shape, when attaching it to the key, there is also a drawback that it is not easy to attach and detach the elastic member, such as having to pinch the entire elastic member by hand and compress it while inserting it into the mounting hole of the key.

[0007] The present invention has been made to solve the above problems, and an object thereof is to provide a keyboard device for a keyboard musical instrument that can sufficiently suppress fluctuations in frictional resistance acting on the hammer during rotation of the hammer, thereby ensuring a stable keyboard touch.

Means for Solving the Problems

[0008] To achieve this object, a keyboard device for a keyboard musical instrument according to claim 1 includes a chassis, a rotatable key extending in the front-rear direction, and a hammer that extends in the front-rear direction, is rotatably supported by the chassis, is connected to the key, and rotates in conjunction with the key when the key is pressed. One of the key and the hammer has a cylindrical connecting shaft, and the connecting shaft so as to cover its outer peripheral surface further includes a cylindrical elastic member attached thereto, and the other of the key and the hammer has a connecting recess whose side surface shape is a long hole and is open outward, and the connecting recess accommodate inside a connecting shaft to which an elastic member is attached and so as to be in contact with the elastic member is fitted into the elastic member, whereby it is rotatably and slidably connected to the one of the key and the hammer.

[0009] According to this configuration, one of the key and the hammer has a cylindrical connecting shaft, and this connecting shaft so as to cover its outer peripheral surfaceA cylindrical elastic member is attached. The other of the key and the hammer has a connecting recess with a long-hole-shaped side surface shape that opens outward, and this connecting recess is accommodate inside a connecting shaft to which an elastic member is attached and so as to be in contact with the elastic member fitted onto the elastic member. As a result, the other of the key and the hammer is connected to the one in a rotatable and slidable manner via the connecting recess, the elastic member, and the connecting shaft, and the hammer rotates in conjunction with the key that has been pressed. In this case, since the to the shaft attached elastic member is cylindrical (concentric), during the rotation of the hammer, the degree of compression of the elastic member and the contact pressure between the connecting recess and the elastic member hardly change. As a result, fluctuations in the frictional resistance acting on the hammer can be sufficiently suppressed, and a stable keyboard touch can be ensured.

[0010] The invention according to claim 2 is the keyboard device of the keyboard musical instrument according to claim 1, wherein the elastic member is partially cut out in the circumferential direction and has a notch penetrating in the length direction, and is fitted onto the connecting shaft via the notch.

[0011] According to this configuration, the elastic member has the notch of the above-described configuration. When attaching the elastic member to the connecting shaft, the elastic member is expanded while pushing it through the notch and then fitted onto the connecting shaft. When the elastic member has appropriate rigidity, the elastic member is attached to the connecting shaft in a retaining state (snap-fitted). Thereby, the elastic member can be easily attached in a retaining state simply by pushing it into the connecting shaft.

[0012] The invention according to claim 3 is the keyboard device of the keyboard musical instrument according to claim 2, wherein the connecting shaft has an engaging recess formed by cutting out a part of the cross-section in the length direction, the elastic member has a pair of protrusions provided at the tip portions facing each other near the notch, and is fitted onto the connecting shaft via the notch, and the pair of protrusions engage with the engaging recess, whereby the elastic member is attached to the connecting shaft in a retaining state.

[0013] According to this configuration, the connecting shaft has the engaging recess of the configuration described above, and the elastic member has a pair of protrusions of the configuration described above in addition to the notch. When attaching the elastic member to the connecting shaft, the elastic member is fitted onto the connecting shaft while expanding the elastic member through the notch. As a result, the pair of protrusions engage with the engaging recesses, and the elastic member is attached to the connecting shaft in a non-removable state (snap-fitted). In this way, the elastic member can be easily attached simply by pushing it into the connecting shaft. Further, since the elastic member is attached in a non-removable state by the engagement of the pair of protrusions and the engaging recesses, the elastic member does not come off the connecting shaft during the use of the keyboard instrument.

[0014] The invention according to claim 4 is characterized in that, in the keyboard device of the keyboard instrument according to claim 2 or 3, the elastic member integrally has a handle portion for operation during attachment and detachment on the side opposite to the notch.

[0015] According to this configuration, by holding the handle portion of the elastic member and pushing and pulling with an appropriate force, the elastic member can be easily attached to the connecting shaft in a non-removable state and can be easily removed from the connecting shaft in a non-removable state whether or not the elastic member has a pair of protrusions.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Best Mode for Carrying Out the Invention

[0017] Hereinafter, with reference to the drawings, preferred embodiments of the present invention will be described in detail. Fig. 1(a) shows only one octave of the keyboard device 1 of the electronic piano to which the present invention is applied. In the following description, first, the basic configuration and operation of the keyboard device 1 will be described, and then the main part of the present invention will be described.

[0018] Fig. 1(b) shows a state in which keys 2 other than the leftmost white key 2a and black key 2b in the keyboard device 1 in Fig. 1(a) are omitted, and Fig. 2 shows a state in which the white key 2a and the black key 2b are removed from the keyboard chassis 4 together with the key support mechanism 6.

[0019] This keyboard device 1 includes a keyboard chassis 4, a plurality of keys 2 composed of white keys 2a and black keys 2b and arranged side by side in the left - right direction, a key support mechanism 6 that is rotatably attached to the keyboard chassis 4 for each key 2 and supports the corresponding key 2 from below, a key switch 3 for detecting the key - pressing information of each key 2, and the like.

[0020] The keyboard chassis 4 includes a chassis main body 4a made of a resin molded product with a predetermined shape by injection - molding a predetermined resin material (for example, ABS resin). As shown in FIG. 3, in this chassis main body 4a, its front part 11, middle part 12, and rear part 13 are all formed so as to extend in the left - right direction (the left - right direction in FIG. 3(a)) as a whole, and these are integrally molded by a plurality of ribs 14 that are spaced apart in the left - right direction and each extend in the front - rear direction. In the following description, in the keyboard chassis 4, the front part 11, middle part 12, and rear part 13 of the chassis main body 4a are respectively referred to as the "chassis front part 11", the "chassis middle part 12", and the "chassis rear part 13".

[0021] The front part 11 of the chassis mainly serves to guide the white keys 2a when the keys are pressed and to regulate the upper and lower limit positions of the front end thereof. In this front part 11 of the chassis, a plurality of white key guides 11a for preventing the lateral movement of the white keys 2a are erected in a state of being arranged side by side in the left-right direction, and are inserted from below for each white key 2a. Further, in the front part 11 of the chassis, engagement holes 11b, 11b penetrating in the vertical direction are provided on both the left and right sides of each white key guide 11a, and two upper limit position regulating parts 21, 21 of the white keys 2a described later penetrate through the engagement holes 11b, 11b and engage therewith. Furthermore, in the front part 11 of the chassis, a stopper mounting part 11c protruding forward and extending in the left-right direction over the entire chassis main body 4a is provided at the front end thereof, and a key upper limit stopper 16a and a key lower limit stopper 16b for the white keys are respectively mounted on the lower surface and the upper surface of this stopper mounting part 11c so as to extend in the left-right direction. Note that a stopper mounting part 11d for the black keys extending in the left-right direction over the entire chassis main body 4a is provided at a predetermined position behind the white key guide 11a in the front part 11 of the chassis, and a key upper limit stopper 17 for the black keys is mounted on this stopper mounting part 11d so as to extend in the left-right direction.

[0022] The middle part 12 of the chassis mainly guides the black keys 2b when the keys are pressed, and swingably supports the first arm 31 and the second arm 32 of the key support mechanisms 6a and 6b for the white keys and black keys, which will be described later. This middle part 12 of the chassis has a flat part 12a in the shape of a flat plate extending in the left-right direction, and a plurality of black key guides 12b erected on this flat part 12a and arranged at appropriate intervals in the left-right direction. Each black key guide 12b is inserted from below for each black key 2b to prevent lateral movement of the black key 2b. Further, at the front part of the middle part 12 of the chassis, a first arm support part 18 for supporting the first arm 31 of the key support mechanism 6 is provided. This first arm support part 18 has a plurality of first support shafts 18a provided so as to extend in the left-right direction between adjacent ribs 14, 14, and the first arm 31 is swingably supported by these first support shafts 18a. Furthermore, at the rear part of the middle part 12 of the chassis, a second arm support part 19 for supporting the second arm 32 of the key support mechanism 6 is provided. This second arm support part 19 has a plurality of second support shafts 19a provided so as to extend in the left-right direction between adjacent ribs 14, 14. The plurality of second support shafts 19a are arranged on the same axis extending in the left-right direction at a position behind and higher than the above-mentioned first support shafts 18a, and the second arm 32 is swingably supported by these second support shafts 19a. Incidentally, at a predetermined position of a middle rail 8, which will be described later, provided below the middle part 12 of the chassis, a first arm lower limit stopper 10b extending in the left-right direction over the entire chassis main body 4a is provided.

[0023] Also, below the keyboard chassis 4, between the front part 11 of the chassis and the middle part 12 of the chassis, the key switch 3 is attached. This key switch 3 is composed of a horizontally long printed circuit board 3a extending in the left-right direction, and a plurality of switch bodies 3b each composed of a rubber switch attached to this printed circuit board 3a for each key 2 and pressed by the first arm 31 when the key is pressed.

[0024] The chassis rear part 13 is mainly for guiding the key 2 vertically at its rear end while preventing lateral sway, and for restricting the upper limit position of the rear end of the first arm 31. As shown in FIGS. 2 and 3(a), the chassis rear part 13 has a plurality of partition walls 13a spaced apart from each other at a predetermined interval in the left-right direction so as to partition adjacent keys 2, 2. Further, as shown in FIG. 3(b), at a predetermined position in the upper part of the chassis rear part 13, a first arm upper limit stopper 10a extending in the left-right direction over the entire chassis main body 4a is provided. The first arm upper limit stopper 10a and the first arm lower limit stopper 10b provided in the chassis intermediate part 12 respectively have a function as a hammer for imparting a touch weight to the key 2, and are for restricting the upper limit position and the lower limit position when the first arm 31 rotates upward and downward with respect to the first arm 31. Furthermore, on the upper part of the chassis rear part 13, a metal cover plate 15 extending in the left-right direction over the entire chassis main body 4a and arranged so as to cover the rear end of the key 2 is attached.

[0025] As shown in FIGS. 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 opening upward and forward and a plurality of second openings 5b opening upward. Through each of the above-described first openings 5a, the first arm 31 of the key support mechanism 6 is engaged with the first support shaft 18a from the outside, and through each of the above-described second openings 5b, the second arm 32 is engaged with the second support shaft 19a from the outside.

[0026] In addition, in the above-described keyboard chassis 4, a plurality of chassis main bodies 4a are connected in a state of being arranged side by side in the left-right direction, and are all screwed in a state of being placed on metal front rails 7, middle rails 8, and rear rails 9 that extend in the left-right direction and are arranged at a predetermined interval in the front-rear direction. Then, the keyboard chassis 4 is fixed on a shelf board (not shown) of the electronic piano via the above-described front rails 7 and rear rails 9.

[0027] 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, and FIG. 4(b) shows an exploded view thereof. As shown in the figure, the white key 2a is formed in a hollow shape that extends a predetermined length in the front-rear direction and is open downward by injection molding a predetermined resin material (for example, AS resin). At the front end portion of the white key 2a, a pair of left and right upper limit position regulating portions 21, 21 are provided, which are formed to extend downward from the left and right side walls and have their lower end portions bent forward. As described above, these upper limit position regulating portions 21, 21 are engaged with the left and right engaging holes 11b, 11b of the front portion of the chassis 11 in a penetrating state, respectively.

[0028] Also, at a predetermined position behind the upper limit position regulating portion 21 in the front portion of the white key 2a, a key front side connecting portion 22 connected to the first arm 31 of the key support mechanism 6a is provided. This key front side connecting portion 22 has a connecting recess 22a formed in a U shape with a long hole-shaped side surface and open forward. Further, in this connecting recess 22a, a key side noise suppressing member 20 is attached so as to cover the entire inner peripheral surface, and when the connecting shaft 35b (described later) of the first arm 31 slides within the connecting recess 22a, generation of noise is suppressed.

[0029] Furthermore, at the rear portion of the white key 2a, a key rear side connecting portion 23 connected to the second arm 32 of the key support mechanism 6a is provided. This key rear side connecting portion 23 has a plate-shaped connecting main body portion 23a that hangs downward from the central portion in the left-right direction of the white key 2a and has a predetermined thickness in the left-right direction, and a pair of left and right engaging convex portions 23b, 23b that project coaxially from the left and right side surfaces of this connecting main body portion 23a, respectively. Also, at the rear portion of the white key 2a, a tool insertion hole 24 is formed that penetrates in the vertical direction and is for inserting a predetermined tool from above when disconnecting the connection between the white key 2a and the second arm 32 of the key support mechanism 6a during maintenance of the keyboard device 1 or the like.

[0030] On the other hand, the key support mechanism 6a includes a first arm 31 and a second arm 32 that engage with each other and are respectively connected to the key front side connecting portion 22 and the key rear side connecting portion 23 of the white key 2a.

[0031] As shown in FIG. 4(b), the first arm 31 is composed of an arm main body 33 and two weights 34, 34 attached to the arm main body 33. The arm main body 33 is formed of a resin molded product having a predetermined shape, such as by injection molding a predetermined resin material (e.g., polyacetal). The arm main body 33 extends a predetermined length in the front-rear direction, and a first arm front-side connecting portion 35 for connecting to the key front-side connecting portion 22 of the white key 2a is provided at the front end portion. The first arm front-side connecting portion 35 has a box portion 35a formed in a box shape that is open upward and forward, and a connecting shaft 35b provided so as to extend in the left-right direction while connecting the front upper ends of the left and right side walls of the box portion 35a. And this connecting shaft 35b is connected to the connecting recess 22a of the key front-side connecting portion 22 of the white key 2a so as to be rotatable and slidable in the front-rear direction.

[0032] Also, the arm main body 33 has a U-shaped bearing portion 36 with an open lower side surface shape at a predetermined position immediately behind the first arm front-side connecting portion 35, and this bearing portion 36 is rotatably engaged with the first support shaft 18a in the keyboard chassis 4. Further, the arm main body 33 is provided with a first arm rear-side connecting portion 37 for connecting to the second arm 32 at a predetermined position behind the bearing portion 36. Specifically, the first arm rear-side connecting portion 37 has a connecting shaft 37a that extends in the left-right direction and both ends of which protrude outward from the left and right side surfaces of the arm main body 33, respectively. And both ends of this connecting shaft 37a are engaged with the connecting recesses 45b, 45b of the second arm front-side connecting portion 45 described later of the second arm 32.

[0033] Two elongated plate-shaped weights 34, 34 are attached to the weight attachment portion 38, which is the rear portion of the arm main body 33, in a state of sandwiching the weight attachment portion 38 from both sides. Each weight 34 is made of a material (e.g., a metal such as iron) having a specific gravity greater than that of the arm main body 33, and is formed into a predetermined shape, such as by pressing a metal plate.

[0034] The second arm 32 is formed of a resin molded product having a predetermined shape by injection molding a resin material similar to the arm main body 33 of the first arm 31. This second arm 32 is shorter than the first arm 31 and extends a predetermined length in the front-rear direction. Further, the second arm 32 has a C-shaped bearing portion 41 with a side surface shape that opens forward near the center in the length direction, and this bearing portion 41 is rotatably engaged with the second support shaft 19a in the keyboard chassis 4.

[0035] In addition, a second arm rear side connecting portion 42 connected to the key rear side connecting portion 23 of the white key 2a is provided at the rear portion of the second arm 32. This second arm rear side connecting portion 42 is formed in a bifurcated shape and has two left and right connecting arm portions 43, 43 that extend a predetermined length in parallel with each other along the length direction of the second arm 32. A connecting hole 43a penetrating in the left-right direction is formed at the rear end portion of each connecting arm portion 43. Then, both connecting arm portions 43, 43 sandwich the connecting main body portion 23a of the key rear side connecting portion 23 of the white key 2a from both the left and right sides between their rear end portions, and each connecting hole 43a is rotatably fitted to the corresponding engaging convex portion 23b of the key rear side connecting portion 23.

[0036] Furthermore, a second arm front side connecting portion 45 connected to the first arm rear side connecting portion 37 of the first arm 31 is provided at the front portion of the second arm 32. This second arm front side connecting portion 45 has a pair of left and right connecting pieces 45a, 45a spaced a predetermined interval from each other in the left-right direction, and a U-shaped connecting recess 45b having a long hole-shaped side surface shape and opening forward is formed in each connecting piece 45a. Then, the left and right connecting pieces 45a, 45a of the second arm front side connecting portion 45 are rotatably and slidably engaged with both end portions of the connecting shaft 37a of the first arm 31 via their connecting recesses 45b, 45b, respectively.

[0037] FIG. 5(a) shows an enlarged view of the black key 2b and its key support mechanism 6b, and FIG. 5(b) shows an exploded view thereof. The black key 2b is formed of the same resin material as the white key 2a by injection molding or the like, extends in the front-rear direction by a predetermined length shorter than the white key 2a, and is formed in a hollow shape that opens downward. At the front lower end of the black key 2b, a front key connecting portion 26 formed substantially the same as the front key connecting portion 22 of the white key 2a is provided. This front key connecting portion 26 has a connecting recess 26a formed in a U-shape with a long hole-shaped side surface and opening forward. Further, the front key connecting portion 26 has an extended portion 26b extending forward by a predetermined length from the front surface of the main body of the black key 2b at the lower front end of the connecting recess 26a, and this extended portion 26b functions as an upper limit position regulating portion of the black key 2b. In the following description, for the black key 2b and the key support mechanism 6b, the same components as those of the above-described white key 2a and the key support mechanism 6a are denoted by the same reference numerals, and detailed description thereof is omitted.

[0038] The key support mechanism 6b that supports the black key 2b is configured substantially the same as the key support mechanism 6a for the white key 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 have exactly the same shape and size as the arm body 33 and the second arm 32 of the key support mechanism 6a for the white key. Note that the two left and right weights 34, 34 of the key support mechanism 6b for the black key have different shapes at the rear from the weight 34 of the key support mechanism 6a for the white key.

[0039] Next, the operation of the key 2 and the key support mechanism 6 in the keyboard device 1 configured as described above will be described. FIG. 6 shows the operation of the white key 2a and its key support mechanism 6a, and FIG. 7 shows the operation of the black key 2b and its key support mechanism 6b.

[0040] In the key-off state shown in FIG. 6(a), when the front end of the white key 2a is pressed down by a finger of the player, the key front side connecting portion 22 of the white key 2a moves downward, whereby the first arm 31 rotates counterclockwise about the first support shaft 18a. Further, with the rotation of the first arm 31, the second arm front side connecting portion 45 engaged with the connecting shaft 37a of the first arm 31 via the connecting recess 45b moves upward. Thereby, the second arm 32 rotates clockwise about the second support shaft 19a. Then, with the rotation of the second arm 32, the key rear side connecting portion 23 connected via the second arm rear side connecting portion 42 at the rear end thereof is pulled down, and the rear end of the white key 2a moves downward.

[0041] Incidentally, when the first arm 31 rotates as described above, as the box portion 35a of the first arm front side connecting portion 35 moves downward, the switch body 3b of the key switch 3 corresponding to the key 2 pressed is pressed from above by the bottom wall of the box portion 35a. Thereby, in the electronic piano, the key press information of the pressed key 2 is detected, and based on the detected key press information, a sound is generated from a speaker (not shown).

[0042] As described above, when the white key 2a is pressed down, with the counterclockwise rotation of the first arm 31, the weight 34 of the first arm 31 inclines rearward and upward as shown in FIG. 6(b), and the rear end abuts against the first arm upper limit stopper 10a from below. Thereby, further rotation of the first arm 31 is blocked. 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, and further pressing down of the white key 2a is blocked.

[0043] The white key 2a to be pressed as described above operates to rotate about a virtual fulcrum P located behind its rear end. The position of this virtual fulcrum P is set such that, for example, the distance from the front end of the white key 2a is about twice the length of the white key 2a itself. As a result, when the front end portion of the white key 2a is pushed down to the lowest position, compared to the key-off state shown in Fig. 6(a), the front end portion of the white key 2a is positioned downward by a predetermined key stroke (e.g., 10 mm), and the rear end portion is positioned downward by a distance of about 1 / 2 of the above key stroke (e.g., 5 mm).

[0044] On the other hand, when the finger is released from the pressed white key 2a, due to the weight of the hammer 34, the first arm 31 of the key support mechanism 6a rotates in the reverse direction as described above, and accordingly, the second arm 32 also rotates in the reverse direction. Along with this, the white key 2a rotates upward about the virtual fulcrum P. Then, a predetermined portion behind the first pivot shaft 18a in the first arm 31 abuts against the first arm lower limit stopper 10b from above, and both upper limit position regulating 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 the original key-off state.

[0045] Also, the operation when the black key 2b is pressed is performed in the same manner as the above-described white key 2a and key support mechanism 6a. That is, in the key-off state shown in Fig. 7(a), when the front end portion of the black key 2b is pushed down, the first arm 31 rotates counterclockwise about the first pivot shaft 18a, and the second arm 32 rotates clockwise about the second pivot shaft 19a. As a result, the black key 2b operates to rotate about a virtual fulcrum Q at the rear. The position of this virtual fulcrum Q is set in the same manner as the virtual fulcrum P of the white key 2a described above, for example, such that the distance from the front end of the black key 2b is about twice the length of the black key 2 itself. Therefore, when the front end portion of the black key 2b is pushed down to the lowest position, compared to the key-off state shown in Fig. 7(a), the front end portion of the black key 2b is positioned downward by a predetermined key stroke, and the rear end portion is positioned downward by a distance of about 1 / 2 of the above key stroke.

[0046] On the other hand, when the finger is released from the depressed black key 2b, the first arm 31 and the second arm 32 of the key support mechanism 6b rotate in the opposite direction to the above, and accordingly, the black key 2b rotates upward about the virtual fulcrum Q. Then, the extended portion 26b of the key front side connecting portion 26 of the black key 2b abuts against the key upper limit stopper 17 from below, the further rotation of the black key 2b is blocked, and it returns to the original key-off state.

[0047] Next, with reference to FIGS. 8 to 11, the connection structure between the key 2 and the first arm 31 according to the present invention will be described. This connection structure is applied in place of the key front side connecting portion 22 and the first arm front side connecting portion 35 shown in FIGS. 3(b) and 4. As shown in FIG. 8, in the present embodiment, the key front side connecting portion 122 of the white key 2a and the front side connecting portion 135 of the first arm 31 are connected via an elastic member 120.

[0048] As shown in FIG. 8(b), the key front side connecting portion 122 has a connecting recess 122a having a long hole shape in the side surface shape and opening forward in a U shape. The width (vertical interval) of the connecting recess 122a is constant in the front-rear direction except for the arc-shaped rear end portion.

[0049] As shown in FIG. 9, the first arm front side connecting portion 135 integrally has a box portion 135a opening upward and forward, and a columnar connecting shaft 135b extending in the left-right direction in a state where the front upper ends of the left and right side walls of the box portion 135a are connected to each other. As shown in FIG. 10(a), an engaging recess 135c is formed at the rear portion of the connecting shaft 135b by cutting out a part of the cross section in the length direction.

[0050] The elastic member 120 is a single part made of an elastic material having an appropriate softness, such as an elastomer, and is attached to the connecting shaft 135b, and has a function of connecting the white key 2a and the first arm 31 and suppressing noise when the two 2a and 31 rotate relative to each other. As shown in FIG. 10(a), the elastic member 120 integrally has a cylindrical main body portion 120a and a handle portion 120b having a rectangular cross-section that protrudes radially outward from the circumferential portion of the main body portion 120a. The inner diameter of the main body portion 120a is substantially equal to the diameter of the connecting shaft 135b. Further, a notch 120c and a pair of protrusions 120d, 120d are formed on the main body portion 120a on the side opposite to the handle portion 120b. The notch 120c is partially cut out in the circumferential direction of the main body portion 120a and penetrates in the length direction, and the pair of protrusions 120d, 120d are provided at the tip portions facing each other in the vicinity of the notch 120c.

[0051] From the above configuration, the white key 2a and the first arm 31 are connected via the elastic member 120 as follows. First, holding the handle portion 120b of the elastic member 120, as shown in FIG. 9, after facing the notch 120c side toward the connecting shaft 135b of the first arm 31, the elastic member 120 is moved (arrow B in the figure, arrow C in FIG. 10(a)), and the portion of the notch 120c is pressed against the connecting shaft 135b. Thereby, while the main body portion 120a of the elastic member 120 is expanded, it is fitted onto the connecting shaft 135b, and as shown in FIG. 10(b), the pair of protrusions 120d, 120d are engaged with the engaging recess 135c of the connecting shaft 135b, whereby the elastic member 120 is attached to the connecting shaft 135b in a state where it is prevented from coming off (snap-fitted).

[0052] As described above, the elastic member 120 can be easily attached simply by pushing it into the connecting shaft 135b. Further, since the elastic member 120 is attached in a state where it is prevented from coming off, the elastic member 120 does not come off from the connecting shaft 135b during the use of the electronic piano.

[0053] Next, as shown in FIG. 8(b), the connecting recess 122a of the white key 2a is fitted into the elastic member 120 from the rear. As a result, the white key 2a and the first arm 31 are connected via the connecting recess 122a, the elastic member 120, and the connecting shaft 135b so as to be rotatable and slidable. The first arm 31 rotates in conjunction with the pressed white key 2a. In this case, since the elastic member 120 is cylindrical (concentric), during the rotation of the first arm 31, the degree of compression of the elastic member 120 and the contact pressure between the connecting recess 122a and the elastic member 120 hardly change. As a result, fluctuations in the frictional resistance acting on the first arm 31 can be sufficiently suppressed, and a stable keyboard touch can be ensured.

[0054] Also, by holding the handle portion 120b of the elastic member 120 and pushing and pulling with an appropriate force, the elastic member 120 can be easily attached to the connecting shaft 135b in a retaining state, and the elastic member 120 in the retaining state can be easily removed from the connecting shaft 135b.

[0055] Note that in the above-described attachment method, the elastic member 120 is attached to the connecting shaft 135b from the front, but it is not limited to this. As shown in FIG. 11, it is also possible to attach it from above. That is, as shown in FIG. 11(a), after fitting most of the elastic member 120 onto the connecting shaft 135b from above to make a temporary fixing state, the white key 2a is moved forward as indicated by the arrow D, and the handle portion 120b of the elastic member 120 is pressed forward by the front-side connecting portion 122 of the key.

[0056] As a result, as shown in FIG. 11(b), while the elastic member 120 rotates in the direction of the arrow E with respect to the connecting shaft 135b, it enters the connecting recess 122a. Finally, the protrusion 120d of the elastic member 120 engages with the engaging recess 135c of the connecting shaft 135b, so that the elastic member 120 is attached to the connecting shaft 135b in a retaining state (the state of FIG. 8(b)). In this way, by fitting the elastic member 120 onto the connecting shaft 135b from above to make a temporary fixing state and simply pressing the handle portion 120b forward with the white key 2a, the elastic member 120 can be easily attached to the connecting shaft 135b while being automatically positioned at a predetermined angle.

[0057] Next, with reference to FIG. 12, a second embodiment of the present invention will be described. As is clear from a comparison between this figure and FIG. 10 showing the first embodiment, in this embodiment, the connecting shaft 235b of the first arm 31 has a circular cross-section with the engaging recess 135c in the first embodiment omitted. Further, the elastic member 220 has a handle portion 220b and a notch 220c as in the first embodiment, while the protrusion 120d in the first embodiment is omitted. Other configurations are the same as those in the first embodiment.

[0058] From the above configuration, when attaching the elastic member 220 to the connecting shaft 235b of the first arm 31, hold the handle portion 220b and, as shown in FIG. 12(a), after facing the notch 220c side toward the connecting shaft 235b, move the elastic member 220 in the direction of arrow C and press it against the connecting shaft 235b. As a result, when the elastic member 220 has appropriate rigidity, the main body portion 220a of the elastic member 220 is expanded and finally fitted (snapped) onto the connecting shaft 235b as shown in FIG. 12(b). Thus, as in the first embodiment, the elastic member 220 can be easily attached in a retaining state simply by pushing it into the connecting shaft 235b. Also, by holding the handle portion 220b and pushing and pulling with an appropriate force, the elastic member 220 can be easily attached to and detached from the connecting shaft 235b.

[0059] Note that the present invention is not limited to the described embodiments and can be implemented in various modes. For example, although the embodiment is an example of applying the present invention to the connection between the white key 2a and the first arm 31, it goes without saying that it may also be applied to the connection between the black key 2b and the first arm 31.

[0060] Also, in the embodiment, the connecting shaft 135b is provided on the first arm 31 side and the connecting recess 122a is provided on the white key 2a side, but this arrangement may be reversed, i.e., a connecting shaft may be provided on the white key 2a side and a connecting recess may be provided on the first arm 31 side. Even in that case, the same effects as those of the above-described embodiment can be obtained.

[0061] Furthermore, the detailed configurations shown in the embodiments, such as the configuration and dimensional relationships of the connection structure between the white key 2a and the first arm 31 as shown in Fig. 8(b), are merely examples, and can be appropriately changed within the scope of the gist of the present invention.

Explanation of Reference Numerals

[0062] 1 Keyboard device 2 Key 2a White key 2b Black key 4 Keyboard chassis (chassis) 31 First arm (hammer) 120 Elastic member 120b Holding part of elastic member 120c Notch of elastic member 120d Protrusion of elastic member 122a Connecting recess 135b Connecting shaft 135c Engaging recess of connecting shaft 220 Elastic member 220b Holding part of elastic member 220c Notch of elastic member 235b Connecting shaft

Claims

1. A chassis, a rotatable key extending in the front-rear direction, a hammer extending in the front-rear direction, rotatably supported by the chassis, connected to the key, and rotating in conjunction with the key when the key is pressed, wherein one of the key and the hammer has a cylindrical connecting shaft, the connecting shaft further includes a cylindrical elastic member attached so as to cover the outer peripheral surface thereof, the other of the key and the hammer has a connecting recess having a long hole-shaped side surface and opening outward, and the connecting recess fits into the elastic member so as to accommodate the connecting shaft to which the elastic member is attached inside and contact the elastic member, whereby the other of the key and the hammer is rotatably and slidably connected to the one of the key and the hammer. The keyboard device of a keyboard instrument is characterized by this.

2. The elastic member is partially cut out in the circumferential direction and has a notch penetrating in the length direction, and is fitted to the connecting shaft through the notch. The keyboard device of a keyboard instrument according to claim 1 is characterized by this.

3. The connecting shaft has an engaging recess formed by cutting out a part of the cross-section in the length direction, the elastic member has a pair of protrusions provided at tip portions facing each other near the notch, is fitted to the connecting shaft through the notch, and the pair of protrusions engage with the engaging recess, whereby the elastic member is attached to the connecting shaft in a state of being prevented from coming off. The keyboard device of a keyboard instrument according to claim 2 is characterized by this.

4. The elastic member integrally has a handle portion for operation during attachment and detachment on the side opposite to the notch. The keyboard device of a keyboard instrument according to claim 2 or 3 is characterized by this.

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