CN116895270A - Keyboard apparatus for keyboard instrument and keys for keyboard apparatus - Google Patents

Abstract

A keyboard apparatus for a keyboard comprising: a hammer that moves vertically pivotally in interlocking with the key that has been pressed; and a cushion pad provided below the hammer, the hammer contacting the cushion pad from above when the hammer having pivotally moved upward according to the depression of the key returns to the original position according to the release of the key. The hammer includes a plurality of projections formed at respective spaced apart positions in order rearward from the hammer support shaft such that they each extend downward. The cushion pad is formed of a plurality of cushion pads which are sequentially contacted by the plurality of projections in order from the projection closest to the hammer support shaft toward the projection farthest from the hammer support shaft when the hammer contacts the cushion pad from above.

Description

Keyboard apparatus for keyboard instrument and keys for keyboard apparatus

Background

Technical Field

The present invention relates to a keyboard apparatus which is applied to a keyboard musical instrument such as an electronic piano and includes hammers pivotally moved in a manner to be linked with key depression, and to a key for a keyboard apparatus which is applied to a keyboard musical instrument such as an electronic piano, and more particularly to a key for a keyboard apparatus which has a weight body mounted inside the key.

Background

Conventionally, as a keyboard device of this type, a keyboard device disclosed in, for example, japanese laid-open patent publication (Kokai) No. 2014-10374 is known. In this keyboard apparatus, hammers are pivotably movably disposed under keys extending in the front-rear direction on a key-by-key basis. In the key release state, each hammer extends in the front-rear direction in a state of being inclined downward toward the rear so that the rear end thereof contacts the stopper from above. The stopper is formed of: a stopper rail extending horizontally in the left-right direction; and a bumper formed on an upper surface of the stopper rail and having a predetermined rectangular shape in a transverse cross section over an entire longitudinal length of the bumper.

On the other hand, conventionally, a key for a keyboard apparatus is known, which is configured to have a weight body mounted in a hollow portion inside the key so as to adjust a touch feeling of the key. For example, in japanese laid-open patent publication (Kokai) No. 2017-44989, a key for a keyboard device is disclosed, the key having: a hole portion opened downward, which is formed in the key body portion; and a protruding drop prevention portion and a displacement suppression portion formed inside the hole portion for pushing the elastically deformable weight body into the hole portion, thereby preventing the weight body from dropping off and suppressing vertical loosening of the weight body.

In the keyboard apparatus including the stopper described above as disclosed in japanese laid-open patent publication (Kokai) No. 2014-10374, when one of the keys is pressed, the hammer associated with the key pivotally moves in a predetermined direction, and the rear end of the hammer moves upward from the stopper. Then, when the key is released, the hammer pivotally moves in the direction opposite to the above-mentioned direction, and the rear end of the hammer moves to come into contact with the stopper from above.

In the above keyboard apparatus, only one stopper is formed at a position corresponding to the rear end of the hammer. In this case, the rear end of the pivotally moved hammer is farthest from the rotation axis of the hammer, so that the kinetic energy of the hammer moved to contact with the stopper is large. Therefore, when the hammer contacts the stopper, the hammer is liable to bounce, and sometimes it takes a long time before the hammer is completely stopped. As a result, during the time until the hammer is completely stopped, there is a possibility that: causing so-called bouncing to vibrate the upper surface of the key associated with the hammer vertically. Further, there is a possibility that: since the rear end of the hammer having a large kinetic energy contacts the single stopper, noise is easily generated.

On the other hand, in the key of the keyboard device disclosed in japanese laid-open patent publication (Kokai) No. 2017-44989, in order to hold the weight body inside the hole portion of the key body portion, a plurality of protruding fall-off prevention portions and a plurality of displacement suppression portions are provided. This complicates the structure of the mold for molding the key body part and increases the manufacturing cost.

Further, conventionally, a key for a keyboard apparatus is known, which has a wooden plate attached to a side portion of a key body made of resin so as to impart a woodiness feeling to the key at low cost. Generally, such a key is configured such that a top portion of the key body is caused to protrude laterally from its corresponding side portion, so that an upper end surface of the wood board is prevented from being exposed to the outside, thereby covering the upper end surface of the wood board. However, this causes a problem that, in the case where the key body has such a shape, uneven cooling rate in the top portion is caused during molding of the key body, which causes uneven shrinkage of the resin material, so that a molding defect called dent is easily generated.

Disclosure of Invention

A first object of the present invention is to provide a keyboard apparatus for a keyboard instrument capable of suppressing occurrence of key bouncing by suppressing bouncing of a hammer when the hammer pivotally moved in conjunction with key depression returns to its original position, and capable of suppressing generation of noise by the hammer.

A second object of the present invention is to provide: a key for a keyboard device capable of not only firmly holding a weight body accommodated inside a key body but also simplifying a mold for molding the key body, thereby suppressing an increase in manufacturing cost; and a key for a keyboard apparatus capable of preventing generation of an indentation on a top portion of a key body during molding of the key body.

In order to achieve the above first object, in a first aspect of the present invention, there is provided a keyboard apparatus for a keyboard instrument, comprising: a keyboard base; a key extending in a front-rear direction and provided on the keyboard base; a hammer extending in the front-rear direction and pivotally supported on the keyboard base via a hammer support shaft below the key, the hammer being vertically pivotally moved in interlocking with the key that has been pressed; and a cushion pad provided below the hammer and having the hammer placed thereon in a key release state, the hammer contacting the cushion pad from above when the hammer having pivotally moved upward according to the depression of the key returns to an original position according to the release of the key, wherein the hammer includes a plurality of projections formed at respective spaced apart positions in an order rearward from the hammer support shaft such that the plurality of projections each protrude downward, and wherein the cushion pad is formed of a plurality of cushion pads respectively associated with the plurality of projections, the plurality of projections successively contacting the plurality of cushion pads respectively associated therewith in an order from the projection closest to the hammer support shaft toward the projection furthest from the hammer support shaft when the hammer contacts the cushion pad from above.

With this configuration, when the hammer that has pivotally moved upward according to the depression of the key returns to its original position according to the release of the key, the hammer contacts the cushion pad from above. Further, the hammers are provided with the plurality of projections formed at the respective spaced apart positions in the order rearward from the hammer supporting shaft such that the plurality of projections each extend downward. In another aspect, the cushion is formed from the plurality of cushions respectively associated with the plurality of protrusions. When the plurality of projections of the hammer contact the plurality of cushion pads respectively, the projections contact the respective associated one of the cushion pads in order from the projection closest to the hammer support shaft toward the projection farthest from the hammer support shaft. Thereby, the kinetic energy of the pivotally moving hammer is gradually reduced by the plurality of cushions, whereby it is possible to prevent the hammer from bouncing when all the projections of the hammer contact the cushions. As a result, even in the case where the key is configured to be interlocked with the hammer, it is possible to suppress occurrence of key bounce. Further, when the hammer contacts the cushion pad, as described above, the hammer contacts the plurality of cushion pads successively, whereby it is possible to gradually reduce the speed and momentum of the pivotally moving hammer, so that it is possible to suppress noise generation as compared with the conventional keyboard apparatus in which the hammer contacts a single stopper.

Preferably, at least one of the plurality of protrusions is formed in a downwardly tapered shape.

With the configuration of this preferred embodiment, at least one of the projections is formed in a downwardly tapered shape, so that when the projection of the hammer contacts the associated one of the cushions from above, it is possible to bring the projection into contact with the associated cushion, so that the contact area between the projection and the cushion gradually increases. Thus, it is possible to suppress noise generation when the hammer contacts the cushion, as compared with the case where the contact area formed when the hammer contacts the cushion is large from the beginning.

Preferably, each cushion pad is formed of an elastic material having a lower rebound resilience as the cushion pad is closer to the hammer support shaft.

With the configuration of this preferred embodiment, the cushions respectively contacted by the projections of the hammers are each formed of an elastic material having a lower rebound resilience as the cushion is closer to the hammer supporting shaft, so that it is possible to gradually reduce the kinetic energy of the pivotally moved hammers while effectively suppressing noise generation when the projections respectively contact the cushion. This makes it possible to effectively suppress the occurrence of noise generation and key bouncing when the hammer contacts the cushion pad.

Preferably, the hammer comprises: a hammer body made of synthetic resin, extending in the front-rear direction, and pivotally supported on the hammer support shaft; and a weight body made of metal and formed such that the weight body extends in the front-rear direction, the weight body being mounted on and extending rearward from the rear end of the hammer body, and the hammer body and the weight body being provided with at least one of the plurality of projections.

With the construction of this preferred embodiment, in the hammer including the hammer body made of synthetic resin and the weight body made of metal, the hammer body and the weight body are respectively provided with at least one of the projections contacting the cushion pad. Thus, with the cushion pad contacted by the projections of the hammer body and the projections of the weight body, by adopting the respective elastic materials suitable for the hammer body and the weight body, it is possible to excellently reduce the impact of the hammer when the hammer contacts the cushion pad.

In order to achieve the above second object, in a second aspect of the present invention, there is provided a key for a keyboard apparatus, the key comprising: a key body made of resin, the key body having at least a top portion and a pair of side portions and being formed in a hollow shape opened downward, the key body extending a predetermined length in a front-rear direction; and a weight body formed of an elastically deformable material and accommodated in a predetermined position inside the key body having a hollow shape, wherein the key body has one groove or a plurality of grooves extending in a front-rear direction in an inner surface of each of the pair of side portions, and wherein the weight body has one engagement protrusion or a plurality of engagement protrusions each formed at a position opposite to each of the one groove or the plurality of grooves when the weight body is in the predetermined position, each of the one engagement protrusion or the plurality of engagement protrusions being engaged with each of the one groove or the plurality of grooves, respectively, thereby holding the weight body inside the key body.

With this configuration, each of the groove or grooves extending in the front-rear direction is formed in the inner surface of each of the side portions of the key body having a hollow shape open downward. Each of the engagement protrusion or protrusions of the weight body is formed at a position opposite to each of the groove or grooves when the weight body is in a predetermined position inside the key body, and thus the engagement protrusion(s) are respectively engaged with the groove(s) when the weight body is accommodated in a predetermined position inside the key body, thereby making it possible to firmly hold the weight body inside the key body.

Further, since the weight body can be held only by each of the groove or grooves formed in the inner surface of the side portion, it is not necessary to provide a plurality of protruding anti-drop portions or the like, whereby the mold for molding the key body can be simplified, thereby enabling an increase in manufacturing cost to be suppressed.

Preferably, one groove or each of the plurality of grooves is formed in an uppermost portion of each of the pair of side portions, and the uppermost portion of each of the pair of side portions is formed to have a thickness dimension smaller than that of the top portion of the key body.

With the configuration of the preferred embodiment, each of the groove or grooves is formed in the uppermost portion of each of the pair of side portions of the key body such that the thickness of the side portion at the uppermost portion where the groove is formed is smaller than the thickness of the top portion of the key body. Thus, for example, even when the key has a structure in which a wooden plate is attached to a side portion of the key body, and in order to cover an upper end surface of the wooden plate, left and right ends of the top portion are formed to protrude laterally, a thickness difference between a portion of the top portion continuous with the side portion and other portions of the top portion becomes very small, so that it becomes difficult to cause a cooling rate difference therebetween during molding of the key body. Therefore, it is possible to effectively suppress the generation of dents on the top portion of the key body.

Preferably, the engagement protrusion or each of the engagement protrusions of the weight body is formed to have a vertical length dimension smaller than that of the groove or each of the grooves.

With the configuration of the preferred embodiment, since the vertical length dimension of each of the groove or grooves formed in the inner surface of the side portion of the key body is larger than the vertical length dimension of each of the engagement protrusion or protrusions formed on the weight body, when the weight body is bonded to the inside of the key body using the adhesive, the adhesive is collected in the gap formed in the groove engaged with the engagement protrusion, whereby it is possible to bond the weight body to the inside of the key body more firmly. Further, the gap serves as a space for receiving additional adhesive.

The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings.

Drawings

Fig. 1A and 1B are perspective views of a part (one octave section) of a keyboard apparatus for an electronic piano to which the present invention is applied, wherein fig. 1A shows the appearance of the keyboard apparatus, and fig. 1B shows a state in which keys other than white keys and black keys at the left end of the keyboard apparatus are omitted;

FIG. 2 is a perspective view of the keyboard apparatus shown in FIG. 1B in a state in which white and black keys with their respective key support mechanisms are removed from the keyboard base;

FIG. 3A is a plan view of the keyboard apparatus shown in FIG. 1B, and FIG. 3B is a cross-sectional view taken along line A-A of FIG. 3A;

fig. 4A and 4B are perspective views of a white key and its key supporting mechanism, wherein fig. 4A shows the white key and the key supporting mechanism in a connected state, and fig. 4B shows the white key and the key supporting mechanism in an exploded state;

fig. 5A and 5B are perspective views of a black key and a key supporting mechanism thereof, wherein fig. 5A shows the black key and the key supporting mechanism in a connected state, and fig. 5B shows the black key and the key supporting mechanism in an exploded state;

Fig. 6A and 6B are views useful for explaining the operation of white keys in a keyboard apparatus, wherein fig. 6A shows a key release state and fig. 6B shows a key depression state;

fig. 7A and 7B are views useful for explaining the operation of the black key in the keyboard apparatus, wherein fig. 7A shows a key release state, and fig. 7B shows a key depression state;

fig. 8A to 8C are views useful for explaining a basic portion of the first embodiment of the present invention, in which fig. 8A is a sectional view similar to fig. 3B, fig. 8B is a view showing a rear portion of the first arm and its surrounding components on an enlarged scale, and fig. 8C is a view showing only the rear portion of the first arm on an enlarged scale.

Fig. 9A to 9D are views showing a series of states in which a plurality of protrusions formed on a rear portion of a first arm are moved into contact with a cushion pad;

fig. 10A is a side view of a key body of a white key in a second embodiment of the present invention, and fig. 10B is a bottom view of the key body;

fig. 11A is a sectional view taken along a line B-B of fig. 10A, and fig. 11B is a sectional view of a white key according to a modification of the present embodiment;

fig. 12A is a perspective view of a weight body, and fig. 12B is a perspective view of a weight body according to a modification of the present embodiment; and

Fig. 13A is a sectional view of the key body in a state in which the weight body is accommodated in the key body, and fig. 13B is a perspective view of the key body in a state in which the weight body according to another modification is accommodated in the key body.

Detailed Description

The present invention will now be described in detail with reference to the accompanying drawings showing preferred embodiments thereof. Fig. 1A shows only one octave section of the keyboard apparatus 1 for an electronic piano to which the present invention is applied. Note that, hereinafter, description will be given first of all of the basic construction of the keyboard apparatus 1 and the operation thereof, and then of the basic parts of the present invention.

Fig. 1B shows a state of the keyboard apparatus 1 shown in fig. 1A, in which the keys 2 other than the white keys 2a and the black keys 2B at the left end of the keyboard apparatus 1 are omitted. Fig. 2 shows a state of the keyboard apparatus 1 shown in fig. 1B, in which the white keys 2a and the black keys 2B are removed from the keyboard base 4 together with their respective key supporting mechanisms 6.

The keyboard apparatus 1 includes: a keyboard base 4; a plurality of keys 2 including white keys 2a and black keys 2b and arranged side by side in the left-right direction; a plurality of key support mechanisms 6 each pivotally mounted on the keyboard base 4 for supporting an associated one of the keys 2 from below; and key switches 3 each for detecting key depression information of an associated one of the keys 2.

The keyboard chassis 4 includes a chassis body 4a formed as a resin molded article, which is manufactured, for example, by injection molding a predetermined resin material (e.g., ABS resin) into a predetermined shape. As shown in fig. 3A and 3B, the base body 4a has a front portion 11, a middle portion 12, and a rear portion 13, each of which extends in the left-right direction (left-right direction as viewed in fig. 3A) as a whole. The front portion 11, the intermediate portion 12, and the rear portion 13 are integrally formed with each other via a plurality of ribs 14 that are disposed in the left-right direction with a certain interval therebetween and that each extend in the front-rear direction. Note that, in the following description, the front portion 11, the intermediate portion 12, and the rear portion 13 of the base body 4a of the keyboard base 4 will be referred to as "base front portion 11", "base intermediate portion 12", and "base rear portion 13", respectively.

The base front 11 is mainly used to guide the white key 2a during the pressing thereof and to restrict the upper and lower limit positions of the front end of the white key 2 a. On the base front 11, a plurality of white key guides 11a, each of which is inserted into each associated one of the white keys 2a from below, are erected in a state of being arranged side by side in the left-right direction so as to prevent lateral swinging of the white keys 2 a. Further, the base front 11 has engagement holes 11b and 11b extending vertically therethrough, which are formed on the left and right sides of each of the white key guides 11a, respectively. A pair of upper left and right position regulating portions 21 and 21 (mentioned below) of the white key 2a are engaged with the engagement holes 11b and 11b in a state of being inserted through the respective engagement holes. Further, the base front portion 11 has a stopper mounting portion 11c formed at the front end thereof, which projects forward and extends along the entire base body 4a in the left-right direction. Key upper limit stoppers 16a and key lower limit stoppers 16b for white keys are respectively mounted on the lower and upper surfaces of the stopper mounting portion 11c so that they extend in the left-right direction. Note that a stopper mounting portion 11d for a black key extending in the left-right direction along the entire base body 4a is provided at a predetermined position of the base front 11, rearward of each white key guide 11a, and a key upper stopper 17 for a black key is mounted on the stopper mounting portion 11d so that it extends in the left-right direction.

The base intermediate portion 12 is mainly used to guide the black key 2b during the pressing thereof and swingably support a first arm 31 and a second arm 32 (described below) of each of the white key associated key support mechanism 6a and the black key associated key support mechanism 6 b. The base intermediate portion 12 has: a flat portion 12a in the form of a flat plate extending in the left-right direction; and a plurality of black key guides 12b standing on the flat portion 12a and arranged in the left-right direction with appropriate intervals therebetween. Each black key guide 12b is inserted into an associated one of the black keys 2b from below to prevent the black keys 2b from swinging sideways. Further, the base intermediate portion 12 is provided with a first arm support portion 18 at a front portion thereof for supporting the first arm 31 of the key support mechanism 6. The first arm support portion 18 has a plurality of first pivot shafts 18a, each of which is disposed between each adjacent two of the ribs 14 and 14 such that the first pivot shaft 18a extends in the left-right direction. The first arm 31 is swingably supported on an associated one of the first pivot shafts 18 a. Further, the base intermediate portion 12 is provided at its rear portion with a second arm support portion 19 for supporting the second arm 32 of the key support mechanism 6. The second arm support portion 19 has a plurality of second pivot shafts 19a, each of which is disposed between each adjacent two of the ribs 14 and 14 such that the second pivot shaft 19a extends in the left-right direction. The plurality of second pivot shafts 19a are arranged at positions rearward of and higher than the first pivot shafts 18a on the same axis extending in the left-right direction, and the second arms 32 are swingably supported on associated ones of the second pivot shafts 19 a. Note that a first arm lower limit stopper 10b extending in the left-right direction along the entire base body 4a is provided at a predetermined position of an intermediate rail 8 (mentioned later), the intermediate rail 8 being provided below the base intermediate portion 12.

Further, the above-mentioned key switch 3 is provided on the lower portion of the keyboard base 4 between the above-mentioned base front portion 11 and base intermediate portion 12. The key switch 3 is formed of a laterally elongated printed circuit board 3a extending in the left-right direction, and a plurality of switch bodies 3b formed of rubber switches attached to the printed circuit board 3a on a key-by-key basis for being pressed by an associated one of the first arms 31 when the key is pressed.

The base rear portion 13 serves mainly to guide the keys 2 in the vertical direction by the rear ends of the keys 2 while preventing lateral swinging of the keys 2, and serves to limit the upper limit position of the rear end of the associated one of the first arms 31. As shown in fig. 2 and 3A, the base rear portion 13 has a plurality of partition walls 13A formed in the left-right direction with a predetermined interval therebetween so as to separate each adjacent two of the keys 2 and 2 from each other. Further, as shown in fig. 3B, a first arm upper limit stopper 10a extending in the left-right direction along the entire base body 4a is provided at a predetermined position of the upper portion of the base rear portion 13. The first arm upper limit stopper 10a and the first arm lower limit stopper 10b provided on the base intermediate portion 12 serve to limit the upper limit position and the lower limit position of the first arm 31, respectively, when the first arm 31 functioning as a hammer for adding a touch weight to the key 2 is pivotally moved upward and downward. Further, a metal cover 15 is mounted on an upper portion of the base rear portion 13, extending along the entire base body 4a in the left-right direction, and disposed to cover the rear end of the key 2.

As shown in fig. 2 and 3A, the base body 4a of the keyboard base 4 constructed as described above is formed with a plurality of first openings 5a opened upward and forward and a plurality of second openings 5b opened upward. The first arms 31 of the key support mechanism 6 are externally engaged with the associated one of the first pivot shafts 18a via the above-mentioned first openings 5a, respectively. Further, the second arms 32 are externally engaged with the associated one of the second pivot shafts 19a via the above-mentioned second openings 5b, respectively.

Further, in the above-described keyboard base 4, the plurality of base bodies 4a are connected to each other so as to be arranged side by side in the left-right direction and are each screwed thereto in a state of being placed on the front rail 7, the middle rail 8, and the rear rail 9, and the rails 7, 8, and 9 each extend in the left-right direction and are arranged with a predetermined interval therebetween in the front-rear direction. The keyboard base 4 is fixed to a keybed (not shown) of the electronic piano via a front rail 7 and a rear rail 9.

Next, the key 2 and the key supporting mechanism 6 will be described. Fig. 4A shows the white key 2a and its key supporting mechanism 6a on an enlarged scale, and fig. 4B shows the white key and its key supporting mechanism in an exploded state. AS shown in fig. 4A and 4B, the white key 2a is formed, for example, by injection molding a predetermined resin material (for example, AS resin) into a hollow shape extending a predetermined length in the front-rear direction and opening downward. The white key 2a has its front end formed with a pair of upper left and upper right regulating portions 21, 21 which protrude downward from the respective side walls of the front end of the white key 2a and each of which has its lower end bent forward. As described hereinabove, the upper left and right position regulating portions 21 and 21 are engaged with the respective left and right engaging holes 11b and 11b of the base front 11 in a state of being inserted therethrough.

Further, at a predetermined position behind the upper limit position adjustment portion 21 of the front portion of the white key 2a, a key front side connection portion 22 connected to the first arm 31 of the key support mechanism 6a is formed. The key front-side connecting portion 22 includes a connecting recess (engaging recess) 22a having a U shape having a groove-like shape in side view and opening forward. Further, the connection recess 22a has a key-side noise suppressing member 20 attached thereto, which is formed to cover the entire inner peripheral surface of the connection recess 22a for suppressing noise generation when a connection shaft 35b (mentioned later) of the first arm 31 slides in the inner peripheral surface of the connection recess 22 a.

Further, the white key 2a has its rear portion provided with a key rear side connection portion 23 connected to the second arm 32 of the key supporting mechanism 6 a. The key rear-side connecting portion 23 has: a plate-like connection body portion 23a which is hung downward from a lateral center portion of the white key 2a and has a predetermined thickness in the left-right direction; and a pair of left and right engaging protrusions 23b and 23b protruding coaxially from left and right side surfaces of the connection body portion 23a, respectively. Further, the rear portion of the white key 2a is formed with a tool insertion hole 24 that extends vertically through the rear portion and is used for inserting a predetermined tool from above to disconnect the white key 2a from the second arm 32 of the key support mechanism 6a, for example, for maintenance of the keyboard apparatus 1.

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 key front-side connecting portion 22 and the key rear-side connecting portion 23 of the white key 2a, respectively.

As shown in fig. 4B, the first arm 31 includes an arm body 33 and two weight bodies 34 and 34 attached to the arm body 33. The arm body 33 is formed as a resin molded article, which is manufactured, for example, by injection molding a predetermined resin material (for example, polyacetal resin) into a predetermined shape. The arm body 33 extends in the front-rear direction by a predetermined length, and has its front end formed with a first arm front side connecting portion 35, the first arm front side connecting portion 35 being connected to the key front side connecting portion 22 of the white key 2 a. The first arm front side connection portion 35 includes: a box portion 35a having a box-like shape that is opened upward and forward; and a connection shaft 35b provided such that it extends in the left-right direction in a state where front side upper ends of the left and right side walls of the box portion 35a are connected to each other. The connection shaft 35b is connected to the connection recess 22a of the key front side connection portion 22 of the white key 2a such that the connection shaft 35b is pivotally movable and slidable in the front-rear direction.

Further, the arm body 33 has a bearing portion 36 formed at a predetermined position immediately behind the first arm front side connecting portion 35. The bearing portion 36 has an inverted U shape that is opened downward in side view, and is pivotally engaged with the first pivot shaft 18a of the keyboard base 4. Further, the arm body 33 has a first arm rear side connecting portion 37 that is connected 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 extending in the left-right direction, with respective opposite ends thereof protruding outwardly from the left and right side surfaces of the arm body 33. Opposite ends of the connection shaft 37a are engaged with connection recesses 45b and 45b of a second arm front side connection portion 45 (mentioned later) of the second arm 32.

Two weight bodies 34 and 34 formed as elongated narrow plates are mounted on the weight body mounting portion 38, which is a rear portion of the arm body 33, in a state of sandwiching the weight body mounting portion 38. Note that each weight body 34 is made of a material (metal such as iron) having a higher specific gravity than the arm body 33, and is formed by pressing a metal plate into a predetermined shape, for example.

The second arm 32 is formed into a resin molded article having a predetermined shape by injection molding 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-rear direction. Further, the second arm 32 has a bearing portion 41 near its longitudinal center, which has a C-shape that is open forward in side view. The bearing portion 41 is pivotally engaged with an associated one of the second pivot shafts 19a of the keyboard base 4.

Further, the second arm 32 is provided with a second arm rear side connecting portion 42 at a rear portion thereof, which is connected to the key rear side connecting portion 23 of the white key 2 a. The second arm rear side connecting portion 42 is formed in a bifurcated shape, and has two left and right connecting arm portions 43 and 43 extending parallel to each other along the longitudinal direction of the second arm 32 by a predetermined length. Each of the connection arm portions 43 has a rear end formed with a connection hole 43a extending through the connection arm portion 43 in the left-right direction. The two connecting arm portions 43 and 43 sandwich the connecting body portion 23a of the key rear side connecting portion 23 of the white key 2a from the left and right sides between the rear ends of the two connecting arm portions, and each connecting hole 43a pivotally fits therein an associated one of the engaging protrusions 23b of the key rear side connecting portion 23.

Further, the second arm 32 is provided with a second arm front side connecting portion 45 at a front portion thereof, which is connected to the first arm rear side connecting portion 37 of the first arm 31. The second arm front side connection portion 45 has a pair of left and right connection portions 45a and 45a arranged at predetermined intervals in the left-right direction. The connection portions 45a and 45a are each formed with a connection recess 45b having a U shape having a groove-like shape in side view and opening forward. The left and right connecting portions 45a and 45a of the second arm front side connecting portion 45 are pivotally and slidably engaged with the respective opposite ends of the connecting shaft 37a of the first arm 31 via the connecting recesses 45b and 45b thereof.

Fig. 5A shows the black key 2B and its key supporting mechanism 6B on an enlarged scale, and fig. 5B shows the black key 2B and the key supporting mechanism 6B in an exploded state. The black keys 2b are formed, for example, by injection molding the same resin material as the white keys 2a into a hollow shape that extends in the front-rear direction for a predetermined length and opens downward, the predetermined length being shorter than the predetermined length over which the white keys 2a extend. The black key 2b has its front lower end provided with a key front side connecting portion 26 formed substantially similar to the key front side connecting portion 22 of the white key 2 a. The key front-side connecting portion 26 has a connecting recess 26a having a U-shape having a groove-like shape in side view and opening forward. Further, the key front-side connecting portion 26 has an extending portion 26b on the lower front end of the connecting recess 26 a. The extension portion 26b extends forward from the front surface of the body of the black key 2b by a predetermined length. The extension portion 26b serves as an upper limit adjustment portion of the black key 2 b. Note that, in the following description, components of the black key 2b and the key supporting mechanism 6b having the same configuration as the above-described white key 2a and key supporting mechanism 6a are denoted by the same reference numerals, and detailed description thereof will be omitted.

The key support mechanism 6b that supports the black keys 2b is configured substantially similar to the above-described white key associated key support mechanism 6a. Specifically, the arm body 33 of the first arm 31 of the key support mechanism 6b and the second arm 32 of the key support mechanism are configured to be completely similar in shape and size to the arm body 33 and the second arm 32 of the white key associated key support mechanism 6a. Note that the two left weight bodies 34 and the right weight body 34 of the black key associated key supporting mechanism 6b are different in shape from the weight body 34 of the white key associated key supporting mechanism 6a in the rear portion thereof.

Next, a description will be given of the operation of the keys 2 and the key support mechanism 6 of the keyboard apparatus 1 constructed as described above. Fig. 6A and 6B are views useful for explaining the operation of the white key 2a and the key supporting mechanism 6A associated therewith. Fig. 7A and 7B are views useful for explaining the operation of the black key 2B and the key supporting mechanism 6B associated therewith.

When the player presses the front end of the white key 2a with his/her finger from the key release state shown in fig. 6A, the key front-side connecting portion 22 of the white key 2a moves downward, whereby the first arm 31 moves pivotally in the counterclockwise direction about the first pivot shaft 18 a. Further, according to the pivotal movement of the first arm 31, the second arm front side connection portion 45 (which is engaged with the connection shaft 37a of the first arm 31 via the connection recesses 45b and 45 b) moves upward. Thereby, the second arm 32 pivotally moves in the clockwise direction about the second pivot shaft 19 a. Then, according to this pivotal movement of the second arm 32, the key rear side connecting portion 23 (which is connected to the second arm 32 via the second arm rear side connecting portion 42 formed at the rear end of the second arm 32) is pulled downward, whereby the rear end of the white key 2a moves downward.

Note that, during the above-mentioned pivotal movement of the first arm 31, the box portion 35a of the first arm front side connection portion 35 moves downward, and therefore, the switch body 3b of one of the key switches 3 associated with the pressed key 2 is pressed from above by the bottom wall of the box portion 35 a. As a result, in the electronic piano, the key depression information of the depressed key 2 is detected, and based on the detected key depression information, sound is generated from a speaker (not shown).

As described hereinabove, in the case where the white key 2a is pressed, according to the counterclockwise pivotal movement of the first arm 31, the weight body 34 of the first arm 31 is inclined such that the weight body 34 becomes higher as it extends rearward, whereby the rear end of the weight body 34 comes into contact with the first arm upper limit stopper 10a from below, as shown in fig. 6B. This prevents further pivotal movement of the first arm 31. When the front end of the white key 2a is pressed to its lowest position, the front end of the white key 2a is in contact with the key lower limit stopper 16b, which prevents the white key 2a from being further pressed.

The white key 2a pressed as above operates such that it pivotally moves about the virtual pivot P located rearward of the rear end thereof. The position of the virtual pivot P is set so that the distance from the front end of the white key 2a is, for example, about twice the length of the white key 2a itself. Thus, when the front end of the white key 2a is pressed to the lowest position, the front end of the white key 2a is positioned lower by a predetermined key stroke (for example, 10 mm) and the rear end of the white key 2a is positioned lower by a distance (for example, 5 mm) of about half of the predetermined key stroke, as compared with the case where the white key 2a is in the key release state shown in fig. 6A.

On the other hand, when the finger is released from the pressed white key 2a, the first arm 31 of the key supporting mechanism 6a is pivotally moved in the direction opposite to the above-mentioned direction by the self weight of the weight body 34, and according to this, the second arm 32 is also pivotally moved in the direction opposite to the above-mentioned direction. According to this pivotal movement of the second arm 32, the white key 2a pivotally moves upward about the virtual pivot P. Then, a predetermined portion of the first arm 31 behind the first pivot shaft 18a moves into contact with the first arm lower limit stopper 10b from above, and the two upper limit adjustment portions 21 and 21 of the white key 2a move into contact with the key upper limit stopper 16a from below, thereby preventing further pivotal movement of the white key 2a and returning the white key 2a to its original key release state.

Further, similarly to the above-described operation of the white key 2a and the key supporting mechanism 6a in response to the pressing of the white key 2a, the operation in response to the pressing of the black key 2b is performed. More specifically, when the front end of the black key 2b is pressed from the key release state shown in fig. 7A, the first arm 31 pivotally moves in the counterclockwise direction about the first pivot shaft 18a, and the second arm 32 pivotally moves in the clockwise direction about the second pivot shaft 19 a. Thereby, the black key 2b is operated such that it pivotally moves about the virtual pivot Q located rearward of the rear end thereof. Note that, similarly to the above-mentioned virtual pivot P of the white key 2a, the position of the virtual pivot Q is set so that the distance from the front end of the black key 2b is, for example, about twice the length of the black key 2b itself. Therefore, when the front end of the black key 2b is pressed to its lowest position, the front end of the black key 2b is positioned lower by a predetermined key stroke and the rear end thereof is positioned lower by a distance of about half of the predetermined key stroke than in the case where the black key 2b is in the key release state shown in fig. 7A.

On the other hand, when the finger is released from the black key 2b that has been pressed, the first arm 31 and the second arm 32 of the key supporting mechanism 6b pivotally move in the respective directions opposite to the above-mentioned directions, and according to this, the black key 2b pivotally moves upward about the virtual pivot Q. Then, the extending portion 26b of the key front-side connecting portion 26 of the black key 2b moves into contact with the key upper limit stopper 17 from below, whereby further pivotal movement of the black key 2b is prevented and the black key 2b returns to its original key release state.

Next, the basic part of the first embodiment of the present invention will be described with reference to fig. 8A to 9D. The basic parts of the first embodiment of the present invention are: the first arm 31 (hammer) provided for each associated one of the keys 2 has its rear portion formed with a plurality of projections 51, and a plurality of cushions 52 respectively contacted by these projections 51 from above are provided.

As shown in fig. 8A and 8B, in the keyboard apparatus 1 of the present invention, along the rear portion (right portion as viewed in fig. 8A) of the first arm 31 provided for each associated one of the keys 2, four protrusions 51 are formed at respective spaced apart positions in order in the front-rear direction. Further, four cushion pads 52 fixed to the rear rail 9 are provided under the four protrusions 51, respectively.

Note that, in the following description, the above-mentioned four projections 51 will be referred to as "first projection 51a", "second projection 51b", "third projection 51c" and "fourth projection 51d" in order from the front side (left side as viewed in fig. 8) closest to the first pivot shaft 18a (hammer supporting shaft). Further, the four cushions 52 will be referred to as "first cushion 52a", "second cushion 52b", "third cushion 52c" and "fourth cushion 52d" in order from the front side.

As shown in fig. 8C, the first projection 51a and the second projection 51b project downward by respective predetermined lengths, and are integrally formed with the arm body (hammer body) 33. Further, the first protrusion 51a has a bottom surface formed to be flat, and the second protrusion 51b is formed in a downwardly tapered shape.

Further, the third protrusion 51c and the fourth protrusion 51d protrude downward by respective predetermined lengths, and are integrally formed with the weight body 34. Further, the third protrusion 51c has a bottom surface formed to be flat, and the fourth protrusion 51d is formed in a downwardly tapered shape.

On the other hand, the four cushion pads 52 are each formed of an elastic material (such as urethane) and extend along the rear rail 9 by a predetermined length in the left-right direction (in the depth direction as viewed in fig. 8). The four cushioning pads 52 each have a predetermined rectangular shape in transverse cross section throughout the longitudinal length thereof, and have upper surfaces extending horizontally.

Further, each of the four cushioning pads 52 is configured to have a lower resilience as it gets closer to the first pivot axis 18 a. That is, of the four cushioning pads 52, the first cushioning pad 52a has the lowest rebound resilience, and the fourth cushioning pad 52d has the highest rebound resilience.

Fig. 9A to 9D show a series of states in which when the first arm 31, which has pivotally moved upward according to the depression of the key 2, returns to its original position according to the release of the key 2, the four protrusions 51 move into contact with the associated one of the cushions 52. More specifically, as shown in fig. 9A, first, the first protrusion 51a of the first arm 31 contacts the first cushion 52a, and then, as shown in fig. 9B, the second protrusion 51B contacts the second cushion 52B. Then, as shown in fig. 9C, the third protrusion 51C contacts the third cushion 52C, and finally, as shown in fig. 9D, the fourth protrusion 51D contacts the fourth cushion 52D. As described above, when the first arm 31 including the above-described four protrusions 51 contacts the four cushion pads 52 from above, the four protrusions 51 contact the respective associated one of the cushion pads 52 in order from the protrusion 51 closest to the first pivot shaft 18 a.

In the keyboard apparatus 1 including the first arm 31 including the four protrusions 51 constructed as described above and the four cushions 52, when the four protrusions 51 of the first arm 31 are moved into contact with the four cushions 52, respectively, the kinetic energy of the pivotally moved first arm 31 is gradually reduced by the four cushions 52, whereby it is possible to prevent the first arm 31 from bouncing when all the protrusions 51 of the first arm 31 contact the cushions 52. As a result, it is possible to suppress occurrence of bouncing of the key 2, which bouncing results in vertical vibration of the upper surface of the key 2 that moves in accordance with the pivotal movement of the first arm 31. Further, when the first arm 31 contacts the cushion pad 52, the first arm 31 contacts the four cushion pads 52a to 52d successively in the mentioned order, whereby it is possible to gradually reduce the speed and momentum of the pivotally moved first arm 31, so that it is possible to suppress noise generation as compared with a conventional keyboard apparatus in which a hammer contacts a single stopper.

Further, since the second protrusion 51b and the fourth protrusion 51d of the four protrusions 51 of the first arm 31 are each formed in a downwardly tapered shape, the two protrusions 51b and 51d contact the respective cushion pads 52b and 52d associated therewith such that the contact area therebetween gradually increases. Thereby, it is possible to suppress noise generation when the first arm 31 contacts the cushion pad 52, compared with the case where the contact area formed when the first arm 31 contacts the cushion pad 52 is large from the beginning.

Further, since each of the four cushion pads 52 is configured to have a lower rebound resilience as it gets closer to the first pivot shaft 18a, it is possible to gradually reduce the kinetic energy of the pivotally moved first arm 31 while effectively suppressing noise generation when the corresponding protrusion 51 of the first arm 31 contacts the cushion pad 52. This makes it possible to effectively suppress noise generation and occurrence of bouncing of the key 2 when the first arm 31 contacts the cushion pad 52.

Note that the present invention is not limited to the above-described embodiments, but can be practiced in various forms. For example, although in the present embodiment, four protrusions 51 are provided on the first arm 31 and four cushioning pads 52 are provided in association with the protrusions 51, the present invention is not limited thereto, but it is also possible to provide two or three, or five or more protrusions 51 on the first arm 31. In these cases, the cushion pads 52 are provided in a number corresponding to the number of the protrusions 51.

Further, although in the above-described embodiment, a description is given of the case where the present invention is applied to the keyboard apparatus 1 in which the depressed keys 2 are operated such that they are pivotally moved about the virtual pivots P and Q located behind the rear ends of the keys 2, respectively, the present invention is not limited thereto, but of course, the present invention can be applied to a general-purpose keyboard apparatus in which the keys are pivotally moved about their own rear ends, respectively, and each of these keys is not provided with the second arm 32. Further, details of the configuration of the first arm 31, the protrusion 51, and the cushion 52 shown in the embodiment are given by way of example only, and they can be appropriately modified within the scope of the subject matter of the present invention.

Next, the basic part of the second embodiment of the present invention will be described with reference to fig. 10A to 13B. The essential part of the second embodiment of the present invention is a weight body attaching structure in which a weight body is attached to the inside of a key body. Although in the present embodiment, a description will be given of an example in which the weight body attachment structure is applied to a white key, the same attachment structure may be applied to a black key.

Fig. 10A is a side view of a key body of a white key as seen from one side thereof, and fig. 10B is a view of the same key body as seen from below. AS described hereinabove, the key body denoted by reference numeral 61 of the white key 2a is formed by injection molding a predetermined resin material (e.g., AS resin). The white key 2a of the present embodiment is, for example, an a key (key for 1a tone), and the key body 61 of the white key 2a includes a large-width portion 61a adjacent to another white key 2a, and a small-width portion 61b adjacent to one of the black keys 2 b. A wood board denoted by reference numeral 62 for imparting a woodiness to the key is attached to left and right side portions of the large-width portion 61a and the small-width portion 61b. Wood materials can be used for the wood board 62, including not only wood materials but also wood grain decorative boards, plywood, medium Density Fiberboard (MDF), and the like. In the present embodiment, a softwood material having a specific gravity of 0.5 or less is used for the wooden plate 62. Examples of such wood materials include spruce and predetermined tropical woods.

As shown in fig. 10B, the key body 61 is formed in a hollow shape opened downward, and the large-width portion 61a is provided with an inner space S for accommodating a weight body 64, 64a or 64B (described later).

Fig. 11A is a sectional view taken along line B-B of fig. 10A. As shown in fig. 11A, the key body 61 has grooves 63 formed in the inner surfaces of a pair of left and right side portions of the key body 61. The grooves 63 are formed in the uppermost portions of the inner surfaces of the side portions of the large-width portion 61a and the small-width portion 61b such that the grooves 63 extend the entire length in the front-rear direction. Further, the top portion of the key body 61 has left and right ends thereof protruding laterally from the pair of respective side portions of the large-width portion 61a and the small-width portion 61b, and covers the upper end surfaces of the wooden boards 62 attached to these side portions. With this configuration, the appearance of the key as viewed laterally becomes similar to the appearance of a wooden key.

Fig. 12A shows a weight body 64 of the present embodiment. The weight body 64 is accommodated in the key body 61 of each key of the keyboard apparatus for adjusting the weight balance of the key, thereby adjusting the touch feeling of the key. The weight body 64 of the present embodiment is made of an elastically deformable material and is formed in a substantially rectangular parallelepiped shape. The weight body 64 can be made of an elastic material, such as synthetic rubber or a thermoplastic elastomer. In the present embodiment, the weight body 64 is made of, for example, chloroprene rubber. The weight body 64 has an engagement protrusion 65 formed along an upper end of each of a pair of opposite side surfaces. When the weight body 64 is accommodated in the inner space S of the key body 61, the engagement protrusion 65 is engaged with the associated one of the grooves 63 of the key body 61, thereby holding the weight body 64 in the inner space S.

The above-mentioned length dimension between the pair of side surfaces of the weight body 64 is set to be approximately equal to the length dimension between the inner surfaces of the pair of side portions of the key body 61. Further, the length dimension between the engaging projections 65 formed on the pair of side surfaces of the weight body 64 is set to be larger than the length dimension between the inner surfaces of the pair of side portions of the key body 61, and is set to be approximately equal to the length dimension between the inner surfaces at the position where the groove 63 is formed.

Fig. 13A shows the key body 61 in a state in which the weight body 64 is accommodated in a predetermined position in the internal space S of the key body 61. The weight body 64 is installed in a predetermined position of the inner space S by being pushed into the inner space S from below the key body 61 opened downward. When the weight body 64 is pushed into the key body 61 from below, although the engaging protrusion 65 first hits the pair of side portions of the key body 61, the weight body 64 is elastically deformed such that the engaging protrusion 65 is bent in a direction opposite to the pushing-in direction of the weight body 64, whereby the weight body 64 is inserted into the internal space S.

Then, when the weight body 64 is pushed further upward and reaches a predetermined position of the inner space S, the engagement protrusion 65 that has been elastically deformed is restored to its original shape in the groove 63, whereby the engagement protrusion 65 is fitted in the groove 63 so as to be engaged therewith. Therefore, when the weight body 64 is accommodated in the predetermined position of the inner space S, it is possible to securely hold the weight body 64 in the key body 61 by the engagement between the engagement protrusion 65 and the groove 63.

Note that the weight body 64 may be more firmly bonded to the inside of the key body 61 by applying an adhesive or a double-sided tape to, for example, the upper surface of the weight body 64.

As described hereinabove, in the key body 61 of the present embodiment, it is possible to firmly hold the weight body 64 by using only the groove 63 formed in the inner surface of the side portion, so that it is not necessary to form an additional protruding portion to prevent the weight body from falling off. Thereby, the mold for molding the key body 61 can be simplified, making it possible to suppress an increase in manufacturing cost.

Note that, in the key body 61 which is a molded article of a resin material, attention needs to be paid to the generation of dents on portions thicker than other portions (such as portions of the top portion continuous with the side portions of the key body 61). In particular, during a musical performance of a player, the top portion of the key body 61 provides a surface that is struck by the fingers of the player at the time of key depression, and thus in order to prevent deterioration of the appearance and touch feeling of the white key 2a, it is important to effectively suppress generation of dents on the top portion of the key body 61. In the key body 61 of the present embodiment, the grooves 63 are formed in the uppermost portions of the inner surfaces of the pair of side portions such that the thickness dimension L1 of the uppermost portions of the side portions is smaller than the thickness dimension L2 of the top portion of the key body. In other words, in the key body 61 of the present embodiment, the grooves 63 formed in the uppermost portions of the side portions have an effect of thickness reduction (downscaling), which reduces the difference in thickness between the portion of the top portion continuous with the side portions and the other portions of the top portion. Thereby, it becomes difficult to cause a difference in cooling rate between a portion of the top portion continuous with the side portion and other portions of the top portion during molding of the key body 61, whereby it is possible to effectively suppress generation of dents on the top portion of the key body 61.

Fig. 12B is a perspective view of a weight body 64a according to a modification of the present embodiment. The weight body 64a according to this modification is different from the weight body 64 described above in that, although in the weight body 64, each of the pair of opposite side surfaces has one engagement protrusion 65 formed to extend along the entire area of the upper end thereof, in the weight body 64a, each of the pair of opposite side surfaces has a plurality of engagement protrusions 65a formed along the upper end thereof. As described above, since the weight body 64a has the plurality of engagement protrusions 65a formed shorter than the engagement protrusions 65, it is possible to deform the engagement protrusions 65a with a small force when the weight body 64a is pushed into the inner space S of the key body 61, whereby the weight body 64a can be easily mounted. Further, when the engaging protrusions 65a are engaged with the grooves 63, spaces are formed in each groove 63 at positions opposite to the discontinuous portions between the engaging protrusions 65a, and thus, for example, when an adhesive is applied to the upper surface of the weight body 64a, the adhesive is collected in these spaces, whereby it is possible to more firmly bond the weight body 64a to the key body 61. Further, the space is also used to receive additional adhesive.

Further, fig. 13B shows a state in which a weight body 64B according to another modification of the present embodiment is accommodated in a predetermined position in the internal space S of the key body 61. The weight body 64b is characterized in that its engaging protrusion 65b is formed smaller than the groove 63. For example, the weight body 64b is configured such that the vertical length dimension of the engagement protrusion 65b is smaller than the vertical length dimension of the groove 63. Thereby, when the engagement protrusion 65b is engaged with the groove 63, a gap G is formed between the engagement protrusion 65b and the groove 63. Therefore, when the adhesive is applied to the upper surface of the weight body 64b, the adhesive is collected in the gap G, whereby it is possible to more firmly bond the weight body 64b to the key body 61. Further, the gap G also serves as a space to receive additional adhesive.

As described hereinabove, according to the present embodiment, when the weight body 64 is accommodated in the predetermined position of the inner space S of the key body 61, the engagement protrusion 65 of the weight body 64 is fitted in the groove 63 formed in the inner surface of the side portion for engagement with the groove 63, whereby it is possible to securely hold the weight body 64 in the key body 61. Further, since it is not necessary to form an additional protruding portion on the key body 61 to prevent the weight body 64 from falling off, a mold for molding the key body 61 can be simplified, whereby it is possible to suppress an increase in manufacturing cost.

Further, the groove 63 is formed in the uppermost portion of the side portion of the key body 61, whereby the thickness dimension L1 of the uppermost portion of the side portion becomes smaller than the thickness dimension L2 of the top portion of the key body 61. Thereby, it becomes difficult to cause a difference in cooling rate between a portion of the top portion continuous with the side portion and other portions of the top portion during molding of the key body 61, whereby it is possible to effectively suppress generation of dents on the top portion of the key body 61.

Note that the present invention is not limited to the above-described embodiments, but can be practiced in various forms. For example, although in the present embodiment, a description is given of the key body 61 having the wooden plate 62 attached to the side portion thereof, as shown in fig. 11B, it is also possible to employ the weight body attaching structure according to the present invention in the key body 61a having no wooden plate attached to the side portion thereof. In the case of the key body 61a shown in fig. 11B, since the left and right ends of the top portion thereof are not formed to protrude laterally from the side portions, a difference in cooling rate caused between a portion of the top portion continuous with the side portions and other portions of the top portion during molding of the key body 61a is small, and the possibility of generating dents on the top portion is very small. In this case, the position where the groove 63a is formed is not limited to the uppermost portion of the inner surface of the side portion, but the groove 63a can be formed at a desired position of the side portion. Further, since it is not necessary to extend the groove 63a in the front-rear direction of the inner surface of the side portion for the entire length as a countermeasure against the generation of the dent, the groove 63a may be formed only at the position where the weight body 64 needs to be fixed. For example, the groove 63a may be formed only anywhere within the range of the inner space S.

It will be further appreciated by those skilled in the art that the foregoing is a preferred embodiment of the invention and that various changes and modifications may be made without departing from the spirit and scope of the invention.

Claims (7)

1. A keyboard apparatus for a keyboard instrument, the keyboard apparatus comprising:

a keyboard base;

a key extending in a front-rear direction and provided on the keyboard base;

a hammer extending in the front-rear direction and pivotally supported on the keyboard base via a hammer support shaft below the key, the hammer being vertically pivotally moved in interlocking with the key that has been pressed; and

a cushion pad provided below the hammer and having the hammer placed thereon in a key release state, the hammer contacting the cushion pad from above when the hammer having pivotally moved upward according to the depression of the key returns to an original position according to the release of the key,

wherein the hammer comprises a plurality of projections formed at respective spaced apart positions in the order rearward from the hammer support shaft such that the plurality of projections each project downward, and

wherein the cushion pad is formed of a plurality of cushion pads respectively associated with the plurality of projections, which are respectively brought into contact with the plurality of cushion pads associated therewith successively in order from the projection closest to the hammer support shaft toward the projection farthest from the hammer support shaft when the hammer contacts the cushion pad from above.

2. The keyboard device of claim 1, wherein at least one of the plurality of protrusions is formed in a downwardly tapered shape.

3. The keyboard apparatus of claim 1, wherein each cushion pad is formed of an elastic material having a lower rebound resilience as the cushion pad is closer to the hammer support shaft.

4. The keyboard apparatus according to claim 1, wherein said hammer comprises:

a hammer body made of synthetic resin, extending in the front-rear direction and pivotally supported on the hammer support shaft, and

a weight body made of metal and formed such that the weight body extends in the front-rear direction, the weight body being mounted on and extending rearward from a rear end of the hammer body, and

wherein the hammer body and the weight body are provided with at least one of the plurality of projections.

5. A key for a keyboard apparatus, the key comprising:

a key body made of resin, the key body having at least a top portion and a pair of side portions and being formed in a hollow shape opened downward, the key body extending a predetermined length in a front-rear direction, and

A weight body formed of an elastically deformable material and accommodated in a predetermined position inside the key body having the hollow shape,

wherein the key body has a groove or grooves extending in the front-rear direction in an inner surface of each of the pair of side portions, and

wherein the weight body has one engagement protrusion or a plurality of engagement protrusions each formed at a position opposite to the one groove or each of the plurality of grooves when the weight body is in the predetermined position, the one engagement protrusion or each of the plurality of engagement protrusions being engaged with the one groove or each of the plurality of grooves, respectively, thereby holding the weight body inside the key body.

6. The key of claim 5, wherein the or each of the plurality of grooves is formed in an uppermost portion of each of the pair of side portions, and

wherein the uppermost portion of each of the pair of side portions is formed to have a thickness dimension smaller than that of the top portion of the key body.

7. The key of claim 5, wherein the or each of the one or more engagement protrusions of the weight body is formed to have a vertical length dimension that is less than a vertical length dimension of the or each of the plurality of grooves.