Support assembly and keyboard apparatus

A support assembly includes a support rotatably disposed with respect to a frame; a jack support portion connected to the support; a jack having a recessed portion in a lower portion of the jack, the jack having the jack support portion inside the recessed portion and being rotatably disposed to the support; and an acting portion fixed to the jack and receiving a downward action. The recessed portion has an open end with a width larger than a width of the jack support portion. The recessed portion may have an open end with a width larger than a width of the jack support portion.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2015-145732, filed on Jul. 23, 2015, the entire contents of which are incorporated herein by reference.

FIELD

The present invention relates to a support assembly for use in a keyboard apparatus.

BACKGROUND

Conventional acoustic pianos such as grand pianos and upright pianos are configured of many components. Also, since assembling these components is very complex, the assembling operation takes a long time. In particular, since an action mechanism provided for each key requires many components, its assembling operation is very complex.

For example, in an action mechanism described in Japanese Unexamined Patent Application Publication No. 2005-292361, a plurality of components operate together, and key operation by key pressing and key releasing is transmitted to a hammer. In particular, a support assembly configuring part of the action mechanism operates with various components assembled together. The support assembly has not only a mechanism which achieves string hammering by the hammer in accordance with key pressing but also an escapement mechanism for releasing a force transmitted to the hammer by key operation immediately before string hammering. This mechanism is an important mechanism for the basic operation of an acoustic piano. In particular, in a grand piano, a double escapement mechanism with a repetition lever and a jack combined together is generally adopted.

The operation of the action mechanism provides a sense (hereinafter referred to as a touch feeling) to a finger of a player through the key. In particular, the structure of the support assembly has an important influence on the touch feeling. For example, the touch feeling by the operation of the escapement mechanism is called let-off.

Since the number of respective components making up the support assembly is large, the manufacturing period is prolonged, and manufacturing cost increased. Therefore, to reduce manufacturing cost, it is desired to simply decrease the number of components and the structure. However, if the structure of the support assembly is changed, the touch feeling at the time of key operation is greatly changed. Therefore, it is difficult to decrease the expense of manufacturing an acoustic piano.

SUMMARY

One object of the present invention is to reduce manufacturing cost of a support assembly while decreasing a change in touch feeling at the time of key operation, compared with a keyboard apparatus of an acoustic piano.

A support assembly according to one embodiment of the present invention includes a support rotatably disposed with respect to a frame; a jack support portion connected to the support; a jack having a recessed portion in a lower portion of the jack, the jack having the jack support portion inside the recessed portion and being rotatably disposed to the support; and an acting portion fixed to the jack and receiving a downward action.

The recessed portion may have an open end with a width larger than a width of the jack support portion.

The support assembly may further include a jack pressing portion being contact with the acting portion from above to press the jack downward.

The jack pressing portion may be an elastic member connected to the support.

The jack may include a projecting portion projecting from the jack, and the acting portion may be provided to the projecting portion.

The jack pressing portion may provide a rotating action of the jack to the acting portion.

The jack may have a stopper regulating a rotation range of the jack with respect to the rotating action.

The jack may have a large jack projecting upward and a small jack projecting in a direction opposite to the projecting portion, and the stopper may regulate the rotation range of the jack by abutting on another member on a deeper side from a player of the large jack, above the small jack, or below the projecting portion and a distance from a rotation center of the jack to a position where the stopper abuts on the other member may be farther than a distance from the rotation center of the jack to the acting portion.

A support assembly according to one embodiment of the present invention includes a support rotatably disposed with respect to a frame and having a recessed portion in an upper portion of the support; a jack rotatably disposed to the support; a support connecting portion fixed to the jack, the support connecting portion being disposed inside the recessed portion and including a rotation center of the jack; and an acting portion fixed to the jack and receiving a downward action.

The recessed portion may have an open end with a width larger than a width of the support connecting portion.

REFERENCE SIGNS LIST

DESCRIPTION OF EMBODIMENTS

In the following, a keyboard apparatus including a support assembly in one embodiment of the present invention is described in detail with reference to the drawings. Embodiments described below are merely examples of embodiments of the present invention, and the present invention should not be interpreted to be restricted to these embodiments. Note that, in the drawings referred to in the present embodiments, identical portions or portions having a similar function are provided with a same sign or similar sign (sign with a numeral merely followed by A, B, or the like), and repetitive description thereof may be omitted. Also, for convenience of description, the dimensional ratios in the drawings (such as ratio between respective structures, or a ratio among length) may differ from an actual ratio, and part of the structure may be omitted from the drawings.

First Embodiment

Structure of Keyboard Apparatus1

A keyboard apparatus1in one embodiment of the present invention is an example obtained by applying one example of the support assembly according to the present invention to an electronic piano. To obtain a touch feeling close to a grand piano at the time of key operation, this electronic piano includes a structure similar to a support assembly included in a grand piano. By usingFIG. 1, a general outline of the keyboard apparatus1according to one embodiment of the present invention is described.

FIG. 1is a side view depicting a mechanical structure of the keyboard apparatus according to one embodiment of the present invention. As depicted inFIG. 1, the keyboard apparatus1according to one embodiment of the present invention includes a plurality of keys110(in this example, eighty-eight keys) and an action mechanism for each of the keys110. The action mechanism includes a support assembly20, a hammer shank310, a hammer320, and a hammer stopper410. Note that whileFIG. 1depicts the case in which the key110is a white key, the key may be a black key. Also, in the following description, terms representing orientations such as a forward side, a deeper side, upward, downward, and sideward from a player are defined as orientations when the keyboard apparatus is viewed from a player's side. For example, in the example ofFIG. 1, the support assembly20is disposed on a forward side from a player when viewed from the hammer320, and is disposed upward when viewed from the key110. Sideward corresponds to a direction in which the keys110are arranged.

The key110is rotatably supported by a balance rail910. The key110rotates in a range from a rest position depicted inFIG. 1to an end position. Here, the “rest position” refers to a key position in a non-pressed state, and the “end position” refers to a key position in a state in which the key is fully pressed. The key110includes a capstan screw120. The support assembly20is rotatably connected to a support flange290, and is resting on the capstan screw120. The support flange290is fixed to a support rail920. Detailed structure of the support assembly20will be described further below. Note that the support flange290and the support rail920are one example of a frame serving as a reference of rotation of the support assembly20. The frame may be formed of a plurality of members, such as the support flange290and the support rail920, or may be formed of one member. The frame may be, as with the support rail920, a rail-shaped member with a long side in the arrangement direction of the keys110, or may be, as with the support flange290, an independent member for each key110.

The hammer shank310is rotatably connected to a shank flange390. The hammer shank310includes a hammer roller315. The hammer shank310is mounted on the support assembly20via the hammer roller315. The shank flange390is fixed to a shank rail930. The hammer320is fixed to an end of the hammer shank310. A regulating button360is fixed to the shank rail930. The hammer stopper410is fixed to a hammer stopper rail940disposed at a position of regulating rotation of the hammer shank310.

A sensor510is a sensor for measuring the position and moving speed (speed immediately before the hammer shank310collides with the hammer stopper410) of the hammer shank310. The sensor510is fixed to a sensor rail950. In this example, the sensor510is a photo interrupter. In accordance with the amount of shielding the optical axis of the photo interrupter by a shielding plate520fixed to the hammer shank310, an output value from the sensor510is changed. Based on this output value, the position and moving speed of the hammer shank310can be measured. Note that a sensor for measuring an operating state of the key110may be provided in place of the sensor510or together with the sensor510.

The above-described support rail920, shank rail930, hammer stopper rail940, and sensor rail950are supported by a bracket900.

[Structure of Support Assembly20]

FIG. 2is a side view depicting the structure of the support assembly in one embodiment of the present invention. The support assembly20includes a support210, a repetition lever240, the jack250, and the torsion coil spring280. The support210and the repetition lever240are coupled together via a flexible portion220. By the flexible portion220, the repetition lever240is rotatably supported with respect to the support210. The support assembly20, except the torsion coil spring280and cushioning materials or the like (such as nonwoven fabric or elastic body) provided at a portion which collides with another member, is a resin-made structure manufactured by injection molding. In this example, the support210and the repetition lever240are integrally formed. Note that the support210and the repetition lever240may be formed as individual components and be attached or bonded together.

The support210has one end side where a through hole2109is formed, and has the other end side where a jack support portion2105projecting upward from the support210is formed. Between the through hole2109and the jack support portion2105, the support210includes a support heel212projecting downward and a spring support portion218projecting upward. Through the through hole2109, a shaft supported by the support flange290is drawn. With this, the support210is rotatably disposed with respect to the support flange290and the support rail920. The support heel212has a lower surface in contact with the above-described capstan screw120. The spring support portion218supports the torsion coil spring280. The jack support portion2105rotatably supports the jack250.

Between the through hole2109and the jack support portion2105, a space SP is formed on a jack support portion2105side from the support heel212. For convenience of description, the support210is sectioned into regions: a first main body portion2101, a bent portion2102, and a second main body portion2103, from a through hole2109side. In this case, by the bent portion2102which couples the first main body portion2101and the second main body portion2103together, the second main body portion2103is disposed on a side closer to the key110(downward) than the first main body portion2101. The jack support portion2105projects upward from the second main body portion2103. According to this sectioning, the above-described space SP corresponds to a region interposed between the bent portion2102and the jack support portion2105above the second main body portion2103. Also, a stopper216is coupled at an end of the support210(an end on a second main body portion2103side). The structure of the jack support portion2105supporting the jack250will be described in detail further below.

To the repetition lever240, a spring contact portion242and an extension portion244are coupled. The spring contact portion242and the extension portion244extend from the repetition lever240to a support210side. The spring contact portion242makes contact with a first arm2802of the torsion coil spring280. The repetition lever240and the extension portion244include two plate-shaped members for interposition from sides of both side surfaces of the jack250. In this example, the extension portion244and the jack250slidably make contact with each other in at least part of a space interposed between these two plate-shaped members.

The extension portion244includes an inner portion2441, an outer portion2442, a coupling portion2443, and a stopper contact portion2444. The inner portion2441is coupled in the repetition lever240on a deeper side from a player (flexible portion220side) of a large jack2502. At a portion where the inner portion2441and the repetition lever240are coupled together, a rib246is provided. The inner portion2441interposes the large jack2502to cross the large jack2502to extend to a forward side from a player (opposite side to the flexible portion220) of the large jack2502. That is, it can also be said that the extension portion244crosses the jack250. At a portion of the intersection between the inner portion2441and the large jack2502, one or both of the inner portion2441and the large jack2502may be provided with a protrusion which decreases a contact area of both of them. The protrusion may be in a dot shape or linear shape.

The outer portion2442is coupled to the repetition lever240on a forward side from a player (opposite side to the flexible portion220) of the jack250(large jack2502). The inner portion2441and the outer portion2442are coupled together at the coupling portion2443. The coupling portion2443interposes a small jack2504from both side surfaces. Here, between the coupling portion2443and the small jack2504, one or both of the coupling portion2443and the small jack2504may be provided with a protrusion which decreases a contact area of both of them. The protrusion may be in a dot shape or linear shape.

The stopper contact portion2444is coupled to the coupling portion2443, and makes contact with the stopper216from downward of the stopper216. That is, the stopper216regulates a rotation range of the repetition lever240to a direction in which a distance between the repetition lever240and the support210spreads (upward). In other words, the extension portion244is connected to the repetition lever240on a jack250side from the rotation center of the repetition lever240and makes contact with the stopper216from downward of the stopper216. Here, the stopper216is connected to the support210below the rotation center of the jack250.

The jack250includes the large jack2502, the small jack2504, and a projecting portion256. The large jack2502projects upward, and the small jack2504projects to the forward side from a player. The jack250is rotatably disposed with respect to the support210. Between the large jack2502and the small jack2504, a support connecting portion2505to be rotatably supported by the jack support portion2105is formed. The support connecting portion2505has a recessed portion2506in a lower portion (support210side or key110side) of the jack250. Inside the recessed portion2506, the jack support portion2105is disposed.

The shape of the support connecting portion2505allows the jack250to fit into the jack support portion2105from above the jack support portion2105. The projecting portion256projects from the large jack2502to a side opposite to the small jack2504and rotates with the jack250. The projecting portion256includes, on its side surface, a spring contact portion2562, and also includes, at its end opposite to the small jack2504, a jack rotation stopper2564.

The spring contact portion2562makes contact with a second arm2804of the torsion coil spring280to receive a downward action from the second arm2804. In other words, the second arm2804makes contact with the spring contact portion2562from above, to press the jack250downward. Furthermore, in other words, the second arm2804provides a rotating action of the jack250to the spring contact portion2562. Here, the spring contact portion2562can be said as an acting portion. Also, the second arm2804or the torsion coil spring280can be said as a jack pressing portion. The jack rotation stopper2564makes contact with the support210from above to regulate a rotation range of the jack250with respect to the rotating action in a direction in which the large jack2502approaches the repetition lever240.

The torsion coil spring280has the stick-shaped first arm2802, the stick-shaped second arm2804, and a coil2806. The coil2806has an annular shape, is supported by the spring support portion218, and makes contact with the spring support portion218at a fulcrum inside the coil2806. The first arm2802functions as an elastic body which provides a rotational force to the repetition lever240so as to make contact with the spring contact portion242to move a player's side of the repetition lever240upward (in a direction away from the support210). The second arm2804functions as an elastic body which provides a rotational force to the jack250so as to make contact with the spring contact portion2562to move the projecting portion256downward (in a direction of approaching the support210). The above is description of the structure of the support assembly20.

[Structure of Jack Support Portion2105and Support Connecting Portion2505]

The structure of the jack support portion2105and the support connecting portion2505is described in detail by usingFIG. 3AandFIG. 3B.FIG. 3Ais an enlarged side view of the jack support portion in the support assembly according to one embodiment of the present invention.FIG. 3Bis a disassembled view of the enlarged side view of the jack support portion in the support assembly according to one embodiment of the present invention. Here,FIG. 3Ais a side view when the support connecting portion2505engages with the jack support portion2105.FIG. 3Bis a side view when the support connecting portion2505and the torsion coil spring280(only the second arm2804is depicted inFIG. 3AandFIG. 3B) are removed from the jack support portion2105. Note that a cover member and so forth disposed sideward of the jack250and the torsion coil spring280are omitted in the side views depicted inFIG. 3AandFIG. 3Bfor convenience of description.

As depicted inFIG. 3AandFIG. 3B, the jack support portion2105includes a jack rotation shaft2110and a coupling portion2112. The coupling portion2112couples the jack rotation shaft2110and the support210. The jack rotation shaft2110has an upper end in an arc shape. The recessed portion2506provided to the support connecting portion2505has an arc shape on an upper surface portion of the recessed portion2506in an arc shape corresponding to the arc shape of the jack rotation shaft2110. The arc of the recessed portion2506has a radius of curvature larger than the radius of curvature of the jack rotation shaft2110. Here, when the upper end of the jack rotation shaft2110and the upper surface portion of the recessed portion2506each have not an arc shape but an oval shape or curved shape, the radiuses of curvature of both of these at a contact point of the jack rotation shaft2110and the upper surface portion of the recessed portion2506may be designed so as to satisfy the above-described conditions. As depicted inFIG. 3A, with the recessed portion2506engaging with the jack rotation shaft2110, the jack250rotates about the jack rotation shaft2110.

Here, a width L1near an open end of the recessed portion2506is larger than a width L2of the jack rotation shaft2110. That is, when the jack250is removed from the support210, the recessed portion2506does not catch the jack rotation shaft2110, and therefore the support connecting portion2505can be smoothly removed from the jack support portion2105. While the structure is illustrated inFIG. 3AandFIG. 3Bin which the width L1is larger than the width L2, the present embodiment is not restricted to this structure, and the width L1may be smaller than the width L2. That is, when the jack250is removed from the support210, the support connecting portion2505may catch the jack support portion2105. In other words, the jack250may be connected to the support210in a snap-fit manner.

While the structure is illustrated inFIG. 3AandFIG. 3Bin which the recessed portion2506has an open end with the width L1in a radial direction of the jack rotation shaft2110(or longitudinal direction of the key110) and the jack rotation shaft2110has a diameter with the width L2in the above-mentioned radial direction, the present embodiment is not restricted to this structure. For example, the structure may be such that the recessed portion has an open end with the width L1in a direction of the axis of the jack rotation shaft2110(or arrangement direction of the keys110) and the jack rotation shaft2110has a diameter with the width L2in the above-mentioned axial direction. The structure may also be such that the recessed portion2506has an open end with the width L1in a radial direction and axial direction of the jack rotation shaft2110and the jack rotation shaft2110has a diameter with the width L2in the radial direction and axial direction of the jack rotation shaft2110. That is, the open end of the recessed portion2506may have a circular shape, and the jack rotation shaft2110may have a globular shape. Here, the open end of the recessed portion2506may have an oval shape, and the jack rotation shaft2110may have a spheroid.

As depicted inFIG. 3A, a distance L4between the jack rotation shaft2110and the jack rotation stopper2564is longer than a distance L3between the jack rotation shaft2110and the spring contact portion2562. Here, the distance L3may be a distance from the rotation center of the jack250to the spring contact portion2562, and the distance L4may be a distance from the rotation center of the jack250to the jack rotation stopper2564. In other words, it can be said that the jack rotation stopper2564is provided at a position at a distance from the rotation center of the jack250farther than a distance of the spring contact portion2562therefrom. With the above-described structure, the jack250is rotated by a downward action received by the spring contact portion2562from the second arm2804to cause the jack rotation stopper2564to make contact with the support210. In this state, the jack250presses the jack rotation shaft2110downward by the recessed portion2506. Note that when the rotation stopper is provided to a deeper side from a player of the large jack2502or above the small jack2504, with the stopper making contact with another member, the jack250presses the jack rotation shaft2110downward by the recessed portion2506. In this manner, the recessed portion2506engages with the jack rotation shaft2110.

While the structure is illustrated inFIG. 3AandFIG. 3Bin which the jack rotation stopper2564is provided at a lower portion of the projecting portion236, the present embodiment is not restricted to this structure. For example, as depicted inFIG. 3C, the large jack2502may include the jack rotation stopper260projecting upward from the large jack2502.FIG. 3Cis an enlarged side view of a jack in the support assembly according to a modification example of one embodiment of the present invention. The jack rotation stopper260regulates the rotation range of the jack250by making contact with the hammer roller315in a rest state. Since the jack rotation stopper260is included in the large jack2502, the state ofFIG. 3Ccan be said such that the large jack2502abuts on the hammer roller315on the deeper side from a player of the large jack2502. Also, in place of the jack rotation stopper260depicted inFIG. 3C, the large jack2502or the small jack2504may function as a rotation stopper of the jack250. That is, the rotation range of the jack250may be regulated by bringing a portion (reference numeral2602) on the deeper side from a player of the large jack2502or an upper portion (reference numeral2604) of the small jack2504into contact with a member fixed to the repetition lever240, the extension portion244, or the support210.

As described above, according to the keyboard apparatus1of the first embodiment of the present invention, the number of components configuring the support assembly can be decreased while the operation of the support assembly is ensured equivalently to conventional ones. Therefore, double escapement can be achieved in a simpler structure compared with the support assembly for use in general grand pianos, and thus the manufacturing cost can be reduced while an influence on touch feeling is decreased.

Also, with the recessed portion2506engaging with the jack rotation shaft2110, the jack250is attached to the support210, and the support assembly20is assembled easily. Furthermore, with the jack250pressed downward, the jack250is inhibited from being detached from the support210. Still further, since the width L1of the open end of the recessed portion2506is larger than the width L2of the jack rotation shaft2110, attachment and removal of the jack250to and from the support210are further facilitated.

With the projecting portion256provided to the jack, flexibility of designing the spring contact portion2562and the jack rotation stopper2564is improved. Also, with the jack rotation stopper2564provided to the jack250, the rotation range of the jack250is regulated, and stable operation of the support assembly20can be obtained. Furthermore, the distance between the jack rotation stopper2564and the rotation center of the jack250is longer than the distance between the spring contact portion2562and the rotation center of the jack250. With this, even if the rotation of the jack250is regulated by the jack rotation stopper2564, the rotation center of the jack250is inhibited from moving from the jack rotation shaft2110to another place. That is, even in the above-described state, the upper surface of the recessed portion2506presses the jack rotation shaft2110downward, and therefore the jack250is prevented from being detached from the support210.

[Operation of Support Assembly20]

Next, the support assembly20is described when the key110is pressed down from the rest position (FIG. 1) to the end position.

FIG. 4is a side view for describing movement of the support assembly in one embodiment of the present invention. When the key110is pressed down to the end position, the capstan screw120pushes up the support heel212to rotate the support210, with the axis of the through hole2109taken as a rotation center. When the support210rotates to move upward, the large jack2502pushes up the hammer roller315to cause the hammer shank310to collide with the hammer stopper410. Note that this collision corresponds to string hammering by a hammer in a conventional grand piano.

Immediately before this collision, while upward movement of the small jack2504is regulated by the regulating button360, the support210(jack support portion2105) further ascends. Therefore, the large jack2502rotates so as to go off from the hammer roller315. Here, by the regulating button360, upward movement of the extending portion244is also regulated. In this example, the regulating button360has also a function of a repetition regulating screw in the action mechanism in a conventional grand piano.

This regulates upward movement of the repetition lever240, which rotates so as to approach the support210. With these operations, a double escapement mechanism is achieved.FIG. 5is a drawing depicting this state. Note that when the key110is being returned to the rest position, the hammer roller315is supported by the repetition lever240, and the large jack2502is returned below the hammer roller315.

[Sound Emission Mechanism of Keyboard Apparatus1]

As described above, the keyboard apparatus1is an example of application to an electronic piano. The operation of the key110is measured by the sensor510, and a sound in accordance with the measurement result is outputted.

FIG. 5is a block diagram depicting the structure of a sound emission mechanism of the keyboard apparatus according to one embodiment of the present invention. A sound emission mechanism50of the keyboard apparatus1includes the sensors510(sensors510-1,510-2, . . .510-88corresponding to the eighty-eight keys110), a signal converting unit550, a sound source unit560, and an output unit570. The signal converting unit550obtains an electric signal outputted from the sensor510, and generates and outputs an operation signal in accordance with an operating state in each key110. In this example, the operation signal is a MIDI-format signal. Therefore, in accordance with the timing when the hammer shank310collides with the hammer stopper410by key-pressing operation, the signal converting unit550outputs Note ON. Here, a key number indicating which of the eighty-eight keys110has been operated and velocity corresponding to a speed immediately before the collision are also outputted in association with Note ON. On the other hand, when key-releasing operation is performed, in accordance with the timing when string vibrations are stopped by a damper in the case of a grand piano, the signal converting unit550outputs the key number and Note OFF in association with each other. To the signal converting unit550, a signal corresponding to another operation such as one on a pedal may be inputted and reflected to the operation signal. The sound source unit560generates a sound signal based on the operation signal outputted from the signal converting unit550. The output unit570is a loudspeaker or terminal which outputs the sound signal generated by the sound source unit560.

According to one embodiment of the present invention, compared with a keyboard apparatus of an acoustic piano, manufacturing cost of the support assembly can be reduced while changes in touch feeling at the time of key operation are decreased.

Second Embodiment

A jack support portion2105A of a support210A and a support connecting portion2505A of a jack250A for use in a keyboard apparatus1A according to a second embodiment of the present invention are described by usingFIG. 6AandFIG. 6B.FIG. 6Ais an enlarged side view of the jack support portion in a support assembly according to one embodiment of the present invention.FIG. 6Bis a disassembled view of the enlarged side view of the jack support portion in the support assembly according to one embodiment of the present invention. Here,FIG. 6Ais a side view when the support connecting portion2505A engages with the jack support portion2105A.FIG. 6Bis a side view when the support connecting portion2505A and a torsion coil spring280A (only a second arm2804A is depicted inFIG. 6AandFIG. 6B) are removed from the jack support portion2105A. Note that a cover member and so forth disposed sideward of the jack250A and the torsion coil spring280A are omitted in the side views depicted inFIG. 6AandFIG. 6Bfor convenience of description. In the second embodiment, components other than the jack support portion2105A and the support connecting portion2505A are similar to those of the first embodiment, and therefore are not described herein.

[Structure of Jack Support Portion2105A and Support Connecting Portion2505A]

As depicted inFIG. 6AandFIG. 6B, the jack support portion2105A is provided with a recessed portion2106A recessed to a key110side on an upper surface (surface on a jack250side) of the support210A. Also, the support connecting portion2505A includes a jack rotation shaft2510A and a coupling portion2512A. The coupling portion2512A couples the jack rotation shaft2510A and the jack250A. The jack rotation shaft2510A has a lower end in an arc shape. On the other hand, the recessed portion2106A has an arc shape on a lower surface portion of the recessed portion2106A corresponding to the arc shape of the jack rotation shaft2510A. The arc of the recessed portion2106A has a radius of curvature larger than the radius of curvature of the jack rotation shaft2510A. Here, when the lower end of the jack rotation shaft2510A and the lower surface portion of the recessed portion2106A each have not an arc shape but an oval shape or curved shape, the radiuses of curvature of both of these at a contact point of the jack rotation shaft2510A and the lower surface portion of the recessed portion2106A may be designed so as to satisfy the above-described conditions. As depicted inFIG. 6A, with the recessed portion2106A engaging with the jack rotation shaft2510A, the jack250A rotates about the jack rotation shaft2510A. In other words, it can be said that the jack250is rotatably connected to the support210A, with the support connecting portion2505A disposed inside the recessed portion2106A.

Here, a width L5near an open end of the recessed portion2106A is larger than a width L6of the jack rotation shaft2510A. That is, when the jack250A is removed from the support210A, the jack rotation shaft2510A does not catch the recessed portion2106A, and therefore the support connecting portion2505A can be smoothly removed from the jack support portion2105A. While the structure is depicted inFIG. 6AandFIG. 6Bin which the width L5is larger than the width L6, the present embodiment is not restricted to this structure, and the width L5may be smaller than the width L6. That is, when the jack250A is removed from the support210A, the support connecting portion2505A may catch the jack support portion2105A. In other words, the jack250A may be connected to the support210A in a snap-fit manner.

While the structure is illustrated inFIG. 6AandFIG. 6Bin which the recessed portion2106A has an open end with the width L5in a radial direction of the jack rotation shaft2510A (or longitudinal direction of the key110) and the jack rotation shaft2510A has a diameter with the width L6in the above-mentioned radial direction, the present embodiment is not restricted to this structure. For example, the structure may be such that the recessed portion has an open end with the width L5in a direction of the axis of the jack rotation shaft2510A (or arrangement direction of the keys110) and the jack rotation shaft2510A has a diameter with the width L6in the above-mentioned axial direction. The structure may also be such that the recessed portion2106A has an open end with the width L5in a radial direction and axial direction of the jack rotation shaft2510A and the jack rotation shaft2510A has a diameter with the width L6in the radial direction and axial direction of the jack rotation shaft2510A. That is, the open end of the recessed portion2106A may have a circular shape, and the jack rotation shaft2510A may have a globular shape. Here, the open end of the recessed portion2106A may have an oval shape, and the jack rotation shaft2510A may have a spheroid.

As depicted inFIG. 6A, a distance L8between the jack rotation shaft2510A and the jack rotation stopper2564A is longer than a distance L7between the jack rotation shaft2510A and the spring contact portion2562A. Here, the distance L7may be a distance from the rotation center of the jack250A to the spring contact portion2562A, and the distance L8may be a distance from the rotation center of the jack250A to the jack rotation stopper2564A. In other words, it can be said that the jack rotation stopper2564A is provided at a position at a distance from the rotation center of the jack250A farther than a distance of the spring contact portion2562A therefrom. With the above-described structure, the jack250A is rotated by a downward action received by the spring contact portion2562A from the second arm2804A to cause the jack rotation stopper2564A to make contact with the support210A. In this state, the jack250A presses the jack rotation shaft2510A downward by the recessed portion2106A. Note that when the rotation stopper of the jack250A is provided to a deeper side from a player of the large jack2502A or above the small jack2504A, even with the stopper making contact with another member, the jack250A presses the jack rotation shaft2510A downward by the recessed portion2106A. In this manner, the recessed portion2106A engages with the jack rotation shaft2510A.

Also in the second embodiment, the jack rotation stopper260as depicted inFIG. 3Cmay be provided to the jack250A. Furthermore, in place of the jack rotation stopper260, as with the first embodiment, the large jack2502or the small jack2504may function as a rotation stopper of the jack250.

As described above, according to the keyboard apparatus1A of the second embodiment of the present invention, the number of components configuring the support assembly can be decreased while the operation of the support assembly is ensured equivalently to conventional ones. Therefore, double escapement can be achieved in a simpler structure compared with the support assembly for use in general grand pianos, and thus the manufacturing cost can be reduced while an influence on touch feeling is decreased.

Also, with the recessed portion2106A engaging with the jack rotation shaft2510A, the jack250A is attached to the support210A, and the support assembly20A is assembled easily. Furthermore, with the jack250A pressed downward, the jack250A is inhibited from being detached from the support210A. Still further, since the width L5of the open end of the recessed portion2106A is larger than the width L6of the jack rotation shaft2510A, attachment and removal of the jack250A to and from the support210A are further facilitated.

With the projecting portion256A provided to the jack, flexibility of designing the spring contact portion2562A and the jack rotation stopper2564A is improved. Also, with the jack rotation stopper2564A provided to the jack250A, the rotation range of the jack250A is regulated, and stable operation of the support assembly20A can be obtained. Furthermore, the distance between the jack rotation stopper2564A and the rotation center of the jack250A is longer than the distance between the spring contact portion2562A and the rotation center of the jack250A. With this, even if the rotation of the jack250A is regulated by the jack rotation stopper2564A, the rotation center of the jack250A is inhibited from moving from the jack rotation shaft2510A to another place. That is, even in the above-described state, the upper surface of the recessed portion2106A presses the jack rotation shaft2510A downward, and therefore the jack250A is prevented from being detached from the support210A.

Third Embodiment

Structure of Keyboard Apparatus1B

As with the keyboard apparatus1of the first embodiment, a keyboard apparatus1B in the third embodiment of the present invention is an example obtained by applying one example of the support assembly according to the present invention to an electronic piano. The keyboard apparatus1B is similar to the keyboard apparatus1, but is different therefrom in the support assembly and the support structure of the support assembly. Also, the keyboard apparatus1B is different from the keyboard apparatus1in the method of regulating upward rotation of a repetition lever provided to the support assembly. In the following description, the above-mentioned differences are mainly described, and common portions are not described.

FIG. 7is a side view depicting the structure of a keyboard apparatus according to one embodiment of the present invention. A support assembly60is fixed to a support rail960. The support rail960is supported by the bracket900. The support assembly20in the first embodiment is rotatably supported with the shaft supported by the support flange290penetrating through the through hole2109. On the other hand, while the support assembly60is similar to the support assembly20in that a support610is rotatably supported by the support rail960, the supporting method is different, as will be described further below. A repetition regulating screw346regulates upward rotation (hammer shank310side) of the support assembly60. Note that the support rail960is an example of a frame serving as a reference of rotation of the support assembly60. The frame may be formed of one member, such as the support rail960, or may be formed of a plurality of members. The frame may be, as with the support rail960, a rail-shaped member with a long side in the arrangement direction of the keys110, or may be an independent member for each key110.

[Structure of Support Assembly60]

FIG. 8is a side view depicting the structure of the support assembly according to one embodiment of the present invention. The support assembly60of the keyboard apparatus1B includes the support610, a repetition lever640, a jack650, an operation regulating portion660, and a coil spring680. The support assembly60, except the coil spring680and cushioning materials or the like (such as nonwoven fabric or elastic body) provided at a portion which collides with another member, is a resin-made structure manufactured by injection molding.

The support610is rotatably supported with respect to the support rail960. The repetition lever640is rotatably supported to the support610. The jack650is rotatably disposed to the support610. Also, the jack650has a large jack6502and a small jack6504. The large jack6502is disposed so as to be able to penetrate through a slit642provided in the repetition lever640. The small jack6504extends from the support610to a forward side from a player. The operation regulating portion660is disposed on a repetition lever640side of the support610.

Also, the support610includes a support heel612, a frame fixing portion632, a flexible portion634, and a mount638. The frame fixing portion632fixes the support610to the support rail960. The flexible portion634is provided between the support610and the frame fixing portion632of each support assembly60, and has flexibility (elasticity). Also, the flexible portion634is integrally formed with the support610and the frame fixing portion632. In a rotating direction of the support assembly60or a plate-thickness direction of the flexibly portion634, the flexible portion634is thinner than at least the support610. Note that while the structure is illustrated inFIG. 8in which the support610, the frame fixing portion632, and the flexible portion634are integrally formed, the present embodiment is not restricted to this structure. For example, the flexible portion634may be fixed to one or both of the support610and the frame fixing portion632by a fixture, adhesive, welding, or the like. Here, the flexible portion634serves as a rotation center of the support assembly60.

The mount638is connected to a repetition lever640side of the support610. On an upper surface (repetition lever640side) of the mount638, a coil spring682acting on the mount638and the repetition lever640and a large-jack stopper6382regulating rotation of the jack650in a direction in which the large jack6502approaches the mount638are provided. Here, part of the large jack6502abutting on the large-jack stopper6382can be said as a jack rotation stopper6564. The coil spring682is a compression spring which acts on the mount638and the repetition lever640in a direction in which the mount638and the repetition lever640go away from each other and functions as an elastic body providing a rotational force to the repetition lever640. Between the large-jack stopper6382and the large jack6502, cushioning materials or the like (such as nonwoven fabric or elastic body) may be provided for reducing noise occurring due to a contact between the large-jack stopper6382and the large jack6502.

The repetition lever640has a flexible portion620, the slit642, an extension portion644, and a support fixing portion648.

The flexible portion620extends to a support610side of the repetition lever640to be coupled to the support fixing portion648. That is, the flexible portion620is provided between the repetition lever640and the support fixing portion648. The flexible portion620is integrally formed with the support fixing portion648and the repetition lever640. Since the plate thickness of the flexible portion620is thinner than the plate thickness of the repetition lever640, the flexible portion620has flexibility (elasticity). Therefore, the repetition lever640rotates about the flexible portion620.

The slit642is provided at a position through which the large jack6502can penetrate, on part of a forward side from a player of the flexible portion620as a rotation center of the repetition lever640. The extension portion644is coupled to a support610side of the repetition lever640on a jack650side from the flexible portion620as the rotation center of the repetition lever640. Also, the extension portion644has slits6442and6444. The support fixing portion648is fixed to the support610by a fixture674.

Note that while the structure is illustrated inFIG. 8in which the repetition lever640, the flexible portion620, and the support fixing portion648are integrally formed, the present embodiment is not restricted to this structure. For example, the flexible portion620may be fixed to one or both of the repetition lever640and the support fixing portion648by a fixture, adhesive, welding, or the like.

With a support connecting portion6505between the large jack6502and the small jack6504connected to a jack support portion6105, the jack650is rotatably disposed with respect to the support610. Part of the large jack6502is provided with a spring contact portion6562to which a coil spring684is connected. The coil spring684is a tension spring which acts on the large jack6502and the support610in a direction in which the large jack6502approaches the mount638and functions as an elastic body providing a rotational force to the jack650.

On a forward side from a player from the mount638, the support610includes two plate-shaped members which interpose the jack support6105from sides of both side surfaces. Between these plate-shaped members, the support connecting portion6505and part of the coil spring684are provided. To inhibit yawing and rolling of the jack650, in at least part of a space interposed between these two plated-shaped members, the jack650and the support610may slidably contact with each other.

The operation regulating portion660is provided opposite to the flexible portion634with reference to the flexible portion620. Also, the operation regulating portion660has an extension portion662, a stopper664, and a guide666. The extension portion662is disposed on a repetition lever640side of the support610. The stopper664and the guide666are disposed to the extension portion662, and each extends from the extension portion662to a forward side from a player. In other words, it can be said that the stopper664and the guide666are projecting portions projecting from the extension portion662to a forward side from a player. The stopper664penetrates through the slit6442provided in the extension portion644, and the guide666penetrates through the slit6444provided in the extension portion644. Note that the slits6442and6444may have any shape as long as the stopper664and the guide666can engage and, for example, may have a shape provided with a groove with which the stopper664and the guide666can engage. The slits6442and the6444can be said as engaging portions.

[Structure of Jack Support Portion6105and Support Connecting Portion6505]

The structure of the jack support portion6105and the support connecting portion6505is described in detail by usingFIG. 9AandFIG. 9B.FIG. 9Ais an enlarged side view of the jack support portion in the support assembly according to one embodiment of the present invention.FIG. 9Bis a disassembled view of the enlarged side view of the jack support portion in the support assembly according to one embodiment of the present invention. Here,FIG. 9Ais a side view when the support connecting portion6505engages with the jack support portion6105.FIG. 9Bis a side view when the support connecting portion6505and the coil spring684are removed from the jack support portion6105.

As depicted inFIG. 9AandFIG. 9B, the jack support portion6105is interposed between the two plate-shaped members of the support610, and has a stick-like shape with a long side sideway. The sectional shape of the jack support portion6105is a circular shape. A recessed portion6506provided to the support connecting section6505has an arc shape on its upper surface portion corresponding to the circular shape of the jack support portion6105. The arc of the recessed portion2106has a radius of curvature larger than the radius of curvature of the jack support portion6105. Here, when the jack support portion6105does not have a circular shape or the upper surface portion of the recessed portion6506has not an arc shape but an oval shape or curved shape, the radiuses of curvature of both of these at a contact point of the jack support portion6105and the upper surface portion of the recessed portion6506may be designed so as to satisfy the above-described conditions. As depicted inFIG. 9A, with the recessed portion6506engaging with the jack support portion6105, the jack650rotates about the jack support portion6105.

Here a width L9near an open end of the recessed portion6506is larger than a width L10of the jack support portion6105. That is, when the jack650is removed from the support610, the recessed portion6506does not catch the jack support portion6105, and therefore the support connecting portion6505can be smoothly removed from the jack support portion6105. While the structure is illustrated inFIG. 9AandFIG. 9Bin which the width L9is larger than the width L10, the present embodiment is not restricted to this structure, and the width L9may be smaller than the width L10. That is, when the jack650is removed from the support610, the support connecting portion6505may catch the jack support portion6105. In other words, the jack650may be connected to the support610in a snap-fit manner.

As depicted inFIG. 9A, a distance L11between the jack support portion6105and the jack rotation stopper6564is longer than a distance L12between the jack support portion6105and the spring contact portion6562. Here, the distance L11may be a distance from the rotation center of the jack650to the jack rotation stopper6564, and the distance L12may be a distance from the rotation center of the jack650to the spring contact portion6562. In other words, it can be said that the jack rotation stopper6564is provided at a position at a distance from the rotation center of the jack650farther than a distance of the spring contact portion6562therefrom. With the above-described structure, the jack650is rotated by a downward action received by the spring contact portion6562from the coil spring684to cause the jack rotation stopper6564to make contact with the large-jack stopper6382. In this state, the jack650presses the jack support portion6105downward by the recessed portion6506.

FIG. 10AandFIG. 10Bare side views of the structure of the stopper and the guide of the support assembly according to one embodiment of the present invention. The side views depicted inFIG. 10AandFIG. 10Bare drawings depicting only the extension portion644, the stopper664, and the guide666in the side view viewed along a D1direction inFIG. 8. Also,FIG. 10Ais a side view of a rest position, andFIG. 10Bis a side view of an end position. The stopper664has a long side in a direction crossing the rotating direction of the repetition lever640and the extension portion644. Also, the guide666and the slit6444have a long side in the rotating direction of the repetition lever640and the extension portion644. The guide666has a groove V6in an inner wall of the slit6444to decrease an area where the guide666and the slit6444slidably contact each other. The above-mentioned groove V6may be coated with grease.

Here, at the rest position depicted inFIG. 8andFIG. 10A, the extension portion644makes contact with the stopper664in the slit6442from a support610side (downward) of the stopper664. In other words, the extension portion644makes contact with the operation regulating portion660from downward of the operation regulating portion660. That is, the stopper664or the operation regulating portion660regulates rotation of the repetition lever640and the extension portion644to a hammer shank310side (upward). Between the extension portion644and the stopper664, cushioning materials or the like (such as nonwoven fabric or elastic body) may be provided for reducing noise occurring due to a contact between the extension portion644and the stopper664.

Also, the extension portion644makes contact with the guide666sideward in the slit6444. Here, sideward means a direction in which the support assembly60is adjacent or an extension direction of the support rail960. In other words, the extension portion644makes contact with the operation regulating portion660sideward. That is, the guide666or the operation regulating portion660inhibits yawing and rolling of the repetition lever640. A portion between the extension portion644and the guide666may be coated with grease for smooth slidable movement of the extension portion644and the guide666.

Note that while the structure is illustrated inFIG. 8,FIG. 10A, andFIG. 10Bin which a slit is provided to the extension portion644connected to the repetition lever640and a projecting portion is provided to the extension portion662connected to the support610, the present embodiment is not restricted to this structure. For example, the structure may be such that a slit is provided to the extension portion662, and a projecting portion penetrating through the slit is provided to the extension portion644.

As described above, according to the keyboard apparatus1B of the third embodiment of the present invention, effects similar to those of the keyboard apparatus1of the first embodiment can be obtained.

[Operation of Support Assembly60]

Next, the support assembly60is described when the key110is pressed down from the rest position (FIG. 7) to the end position.

FIG. 11is a side view for describing movement of the support assembly in one embodiment of the present invention. When the key110is pressed down to the end position, the capstan screw120pushes up the support heel612to rotate the support610, with the axis of the flexible portion634taken as a rotation center. When the support610rotates to move upward, the large jack6502pushes up the hammer roller315to cause the hammer shank310to collide with the hammer stopper410.

Immediately before this collision, while upward movement of the small jack6504is regulated by the regulating button360, the support610(jack support portion6105) further ascends. Therefore, the large jack6502rotates so as to go off from the hammer roller315. Here, by the repetition regulating screw346, upward movement of the repetition lever640is regulated. This regulates upward movement of the repetition lever640, which rotates so as to approach the support610. With these operations, a double escapement mechanism is achieved.FIG. 11is a drawing depicting this state. Note that when the key110is being returned to the rest position, the hammer roller315is supported by the repetition lever640, and the large jack6502is returned below the hammer roller315.

Fourth Embodiment

A jack support portion6105C of a support610C and a support connecting portion6505C of a jack650C for use in a keyboard apparatus1C according to a fourth embodiment of the present invention are described by usingFIG. 12AandFIG. 12B.FIG. 12Ais an enlarged side view of the jack support portion in the support assembly according to one embodiment of the present invention.FIG. 12Bis a disassembled view of the enlarged side view of the jack support portion in the support assembly according to one embodiment of the present invention. Here,FIG. 12Ais a side view when the support connecting portion6505C engages with the jack support portion6105C.FIG. 12Bis a side view when the support connecting portion6505C and a coil spring684C are removed from the jack support portion6105C. In the fourth embodiment, components other than the jack support portion6105C and the support connecting portion6505C are similar to those of the first embodiment, and therefore are not described herein.

[Structure of Jack Support Portion6105C and Support Connecting Portion6505C]

As depicted inFIG. 12AandFIG. 12B, the jack support portion6105C is provided with a recessed portion6106C recessed to a key110side on an upper surface (surface on a jack250C side) of the support610C. The recessed portion6106C is provided to both of two plate-shaped members of the support610C. Also, the support connecting portion6505C projects to both sides from the jack650C near a coupling portion between a large jack6502C and a small jack6504C. The sectional shape of the support connecting portion6505C is a circular shape. The recessed portion6106C has an arc shape on a lower surface portion corresponding to the circular shape of the support connecting portion6505C. The arc of the recessed portion6106C has a radius of curvature larger than the radius of curvature of the circle of the support connecting portion6505C. Here, when the support connecting portion6505does not have a circular shape or the lower surface portion of the recessed portion6106C has not an arc shape but an oval shape or curved shape, the radiuses of curvature of both of these at a contact point of the support connecting portion6505C and the lower surface portion of the recessed portion6506C may be designed so as to satisfy the above-described conditions. As depicted inFIG. 12A, with the recessed portion6106C engaging with the support connecting portion6505C, the jack650C rotates about the support connecting portion6505C.

Here, a width L13near an open end of the recessed portion6106C is larger than a width L14of the support connecting portion6505C. That is, when the jack650C is removed from the support610C, the support connecting portion6505C does not catch the recessed portion6106C, and therefore the support connecting portion6505C can be smoothly removed from the jack support portion6105C. While the structure is illustrated inFIG. 12AandFIG. 12Bin which the width L13is larger than the width L14, the present embodiment is not restricted to this structure, and the width L13may be smaller than the width L14. That is, when the jack650C is removed from the support610C, the support connecting portion6505C may catch the jack support portion6105C. In other words, the jack650C may be connected to the support610C in a snap-fit manner.

As depicted inFIG. 12A, a distance L15between the support connecting portion6505C and the jack rotation stopper6564C is longer than a distance L16between the support connecting portion6505C and the spring contact portion6562C. Here, the distance L15may be a distance from the rotation center of the jack650C to the jack rotation stopper6564C, and the distance L16may be a distance from the rotation center of the jack650C to the spring contact portion6562C. In other words, it can be said that the jack rotation stopper6564C is provided at a position at a distance from the rotation center of the jack650C farther than a distance of the spring contact portion6562C therefrom. With the above-described structure, the jack650C is rotated by a downward action received by the spring contact portion6562C from the coil spring684C to cause the jack rotation stopper6564C to make contact with a large-jack stopper6382C. In this state, the jack650C presses the jack support portion6105C downward by the recessed portion6506.

As described above, according to the keyboard apparatus1C of the fourth embodiment of the present invention, effects similar to those of the keyboard apparatus1A of the second embodiment can be obtained.

In the above-described embodiment, an electronic piano is described as an example of a keyboard apparatus to which a support assembly is applied. On the other hand, the support assembly of the above-described embodiment can be applied to a grand piano (acoustic piano). In this case, the sound emission mechanism corresponds to a hammer and a string. The string generates a sound by colliding a hammer in accordance with key pressing. In the case the large jack2502is returned below the hammer roller315after string hammering by the hammer, the repetition lever240may be omitted. For example, the keyboard apparatus1may have a structure whereby when the key110is returned to the rest position a part of the hammer assembly is supported by another member instead of the repetition lever240and the large jack2502is returned below the hammer roller315.

The present invention is not restricted to the above-described embodiments but can be modified as appropriate in a scope not deviating from the gist of the present invention.