Patent Application
20070131092
1. Field of the Invention
The present invention relates to a tone plate for use in a keyboard-type tone plate percussion instrument, which is adapted to vibrate to thereby generate a musical tone of a specific tone pitch when struck, a method for fabricating the tone plate, a tone generator unit of a tone plate percussion instrument including tone plates and a resonance box for causing musical tones generated by the tone plates to resonate therein, and a keyboard-type percussion instrument.
2. Description of the Related Art
As disclosed in Japanese Utility Model Laid-open Publication (Kokai) No. H05-081895, a conventional keyboard-type tone plate percussion instrument includes, as sounding members, a plurality of tone plates each adapted to generate, when struck, a musical tone of a specific tone pitch (hereinafter referred to as the first prior art). The tone plates are generally formed into a flat plate, and in most keyboard-type tone plate percussion instruments, they are differed from one another mainly in length so as to generate different specific tone pitches.
In the tone plate percussion instrument of this type, it has also been known to provide a resonance box for causing musical tones generated by a plurality of tone plates to resonate therein. For example, the keyboard-type tone plate percussion instrument according to the first prior art is provided with a resonance box having resonance chambers in each of which a corresponding one of musical tones generated by the tone plates is caused to resonate.
In this keyboard-type tone plate percussion instrument, the tone plates constituting a tone plate group are fixed for vibration by means of a pin or the like to a supporting part, which is turn fixed to the musical instrument main body. The resonance box is arranged close to the tone plate group and fixed to the instrument main body by wood screws extending through elongated holes that are formed in resonance-box fixing rails attached to the instrument main body.
Further, as disclosed in the keyboard-type tone plate percussion instrument according to the first prior art, it has been known to provide percussion units such as hammer action units in the percussion instrument in addition to sounding members such as tone plates, whereby in response to a key depression operation, a corresponding percussion unit hits a corresponding one of the sounding members to thereby generate a musical tone of a specific tone pitch.
In this keyboard-type tone plate percussion instrument, the sounding members are fixed for vibration to a supporting part of the instrument by means of a pin or the like, and resonance boxes are provided that have an opening side arranged close to the sounding members. The percussion units are each disposed below a corresponding one of the sounding members. The just-mentioned mechanism is constructed into an upper and lower two-stage structure.
In the keyboard-type tone plate percussion instrument based on the first prior art, however, the tone plate group and the resonance box are fixed to the musical instrument main body independently of each other, making it difficult to carry out the mounting operation thereof to the musical instrument. In addition, the tone plates must be mounted one by one, thus further complicating the tone plate mounting operation.
In order to change the tone color of this tone plate percussion instrument, the tone plate group and/or the resonance box must be individually replaced by different ones. Upon such replacement, a fine adjustment is required of the distance and positional relation between the tone plate group and the resonance box in order to maintain the desired sounding capability of the tone plate percussion instrument, which further increases the difficulty of replacement. This also applies to the maintenance of the tone plate group and/or the resonance box.
Moreover, in the keyboard-type tone plate percussion instrument according to the first prior art, there is a fixed, one-on-one based relationship between the keys, percussion units, and sounding members. Therefore, when any one of the keys is depressed, a percussion unit fixedly corresponding thereto is driven to strike a sounding member, which in turn fixedly corresponds to the driven percussion unit. Thus, that sounding member which is struck by a given percussion unit is always the same. It is therefore impossible to carry out key transposition, for example. From the viewpoint of providing a variety of musical performances, there is a room for improving the keyboard-type tone plate percussion instrument.
Still another type of tone plate has also been known as disclosed in Japanese Patent Laid-open Publication (Kokai) No. H08-202351, in which the tone plate has its thickness varying in the longitudinal direction thereof. The tone plate is made thinner at a longitudinally center portion thereof by cutting or the like so as to attain a frequency ratio of 1:4:8 between primary, secondary, and tertiary modes in which the tone plate vibrates, thereby improving harmony, volume, and interval of chord tone generated by the tone plate percussion instrument (hereinafter referred to as the second prior art)
However, in the keyboard-type tone plate percussion instrument according to the second prior art, tone plates for generating lower pitch tones are made longer in entire length. In particular, tone plates for a low tone pitch range are wide in width and extremely long in entire length. The necessity for satisfying the above requirement for the tone plate size poses a problem that the degree of freedom in design decreases. For example, this results in increase in the entire instrument size, especially in a case where the keyboard-type tone plate percussion instrument includes a large number of tone plates so as to cover a wide range of pitch.
A first object of the present invention is to provide a tone plate for use in a keyboard-type tone plate percussion instrument, which makes it easy to reduce the entire length and width of the tone plate to thereby increase the degree of freedom in design, as well as to provide a method of fabricating the tone plate, and a keyboard-type percussion instrument.
A second object of the present invention is to provide a tone generator unit of a tone plate percussion instrument, which makes it easy to replace the entire tone plate unit while maintaining a proper positional relationship between a resonance box and tone plates to thereby easily carry out tone color change in an acoustic musical instrument as well as to provide a keyboard-type percussion instrument.
To attain the first object, according to a first aspect of the present invention, there is provided a tone plate for use in a keyboard-type tone plate percussion instrument, comprising a longitudinal central portion, first and second ends, first and second supported portions respectively located at first longitudinal locations in the tone plate which are closer to the first and second ends than to the longitudinal central portion and at each of which a vibration node can be formed, first and second mass concentrating portions extending toward the first and second ends from second longitudinal locations in the tone plate that are on a side close to the first and second ends with respect to the first and second supported portions, respectively, and first and second thinner portions respectively provided between the longitudinally central portion and the first supported portion and between the longitudinally central portion and the second supported portion, wherein the tone plate is made of a single material and formed into one piece, the tone plate vibrating to generate a musical tone of a specific tone pitch when it is struck with being supported at the first and second supported portions thereof.
With this construction, it is easy to reduce the entire length and width of the tone plate, thereby making it possible to increase the degree of freedom in designing the tone plate.
Preferably, the first and second mass concentrating portions are each thicker than the longitudinally central portion in a thickness direction of the tone plate, and the first and second thinner portions are each thinner than the longitudinally central portion in the thickness direction of the tone plate.
With this construction, it is easy to equalize the widths of a plurality of tone plates having different tone pitches.
Preferably, the first and second mass concentrating portions and the longitudinally central portion extend beyond the first and second thinner portions toward one side of the tone plate in the thickness direction of the tone plate.
With this construction, the tone plate can be formed by cutting only those parts of a plate material which are on one side of the plate material as viewed in the thickness direction thereof, making it easy to carry out machining for fabrication of the tone plate from the plate material.
Preferably, the first and second supported portions are comprised of engagement portions that are formed substantially along a width direction of the tone plate.
With this construction, a plurality of tone plates can collectively be held by means of a cord member that is adapted to be engaged with the engagement portions formed in the tone plates, for instance.
To attain the second object, according to a second aspect of the present invention, there is provided a method for fabricating a tone plate for use in a keyboard-type tone plate percussion instrument from an elongated member made of a single material and having a rectangular cross section, the tone plate comprising a longitudinal central portion, first and second ends, and first and second supported portions respectively located at first longitudinal locations in the tone plate which are closer to the first and second ends than to the longitudinal central portion and at each of which a vibration node can be formed, the method comprising the steps of (a) removing, by cutting and/or grinding, a first part of the elongated member extending between first and second equivalent longitudinal locations therein, which respectively correspond to second longitudinal locations in the tone plate that are on a side close to the first and second ends with respect to the first and second supported portions, to thereby form first and second mass concentrating portions of the tone plate respectively extending toward the first and second ends from the second longitudinal locations, and (b) forming first and second thinner portions of the tone plate at second and third parts of the elongated member, which respectively correspond to between the longitudinally central portion and the first supported portion and between the longitudinally central portion and the second supported portion of the tone plate, wherein the tone plate vibrates to generate a musical tone of a specific tone pitch when it is struck with being supported at the first and second supported portions thereof.
According to this construction, it is easy to reduce the entire length and width of the tone plate, thereby making it possible to increase the degree of freedom in designing the tone plate. In addition, the tone plate can easily be fabricated.
Preferably, in the step (b), part of the elongated member to be removed is removed from one direction, to thereby form the first and second thinner portions so as to be thinner than the longitudinally central portion in a thickness direction of the elongated member, while permitting each of the first and second mass concentrating portions to be thicker than the longitudinally central portion in the thickness direction of the elongated member.
With this construction, the tone plate can be fabricated by removing the part to be removed of the elongated member from one direction, which increases the ease of fabrication of the tone plate and which makes it easy to equalize widths of tone plates having different tone pitches.
To attain the second object, according to a third aspect of the present invention, there is provided a tone generator unit of a tone plate percussion instrument, comprising a plurality of tone plates each adapted to vibrate to generate a musical tone of a specific tone pitch when struck, and a resonance box having a plurality of resonance chambers corresponding to respective ones of the plurality of tone plates and each having an opening side thereof, wherein the plurality of tone plates are mounted to the resonance box so as to be capable of vibrating, with each of the tone plate located close to the opening side of a corresponding one of the resonance chambers, whereby the resonance box and the plurality of tone plates are formed into one unit.
With this construction, the entire tone generator unit can easily be replaced while maintaining a proper positional relationship between the resonance box and the tone plates, which makes it easy to change the tone color in the acoustic musical instrument.
Preferably, the tone generator unit further includes a holder member for collectively holding at least two of the plurality of tone plates so as to be capable of vibrating, and attachment members for attaching the holder member to the resonance box.
With this construction, the tone plate group can collectively be mounted to and detached from the resonance box, thereby increasing the ease of mounting of the tone plates and replacement thereof.
Preferably, the holder member is comprised of a cord member, each of the at least two of the plurality of tone plates is formed with through holes that extend in a direction of array of the plurality of tone plates, and the holder member passes through the through holes formed in the at least two of the plurality of tone plates whereby the at least two of the plurality of tone plates are held by the holder member so as to be suspended therefrom.
With this construction, the tone plate group can collectively be handled using the cord member, which further increases the ease of mounting the tone plates and replacement thereof.
Preferably, a distance between adjacent ones of the plurality of tone plates is temporarily determined by an associated at least one of the attachment members when the plurality of tone plates are mounted to the resonance box.
With this construction, when the tone plates are mounted to the resonance box, they can easily be positioned in the direction in which the keys are arranged.
Preferably, the resonance box includes first and second common walls extending substantially along a direction in which the plurality of tone plates are arranged, and a plurality of chamber-defining members that are formed between the first and second common walls and define the plurality of resonance chambers, among the plurality of resonance chambers, a plurality of predetermined resonance chambers corresponding to at least part of a range of the percussion instrument are defined to correspond, on a one-on-one basis, to associated ones of the plurality of tone plates, each of the plurality of predetermined resonance chambers overlaps at least one of other predetermined resonance chambers as seen from front thereof, and a maximum width of each of the plurality of predetermined resonance chambers as viewed in the direction in which the plurality of tone plates are arranged is as large as at least twice a width of the corresponding tone plate.
With this construction, the tone plate group and the resonance box of the entire musical instrument can be constructed into a single-stage structure while ensuring proper widths of resonance chambers.
To attain the first object, according to a fourth aspect of the present invention, there is provided a keyboard-type percussion instrument, comprising a plurality of keys that constitute a keyboard, and a plurality of sounding members arranged in a direction in which the plurality of keys are arranged, each of the plurality of sounding members being made of a single material and formed into one piece, wherein each of the plurality of sounding members comprises a longitudinal central portion, first and second ends, first and second supported portions respectively located at first longitudinal locations which are closer to the first and second ends than to the longitudinal central portion and at each of which a vibration node can be formed, first and second mass concentrating portions extending toward the first and second ends from second longitudinal locations in the sounding member that are on a side close to the first and second ends with respect to the first and second supported portions, respectively, and first and second thinner portions respectively provided between the longitudinally central portion and the first supported portion and between the longitudinally central portion and the second supported portion, and wherein the each sounding member vibrates to generate a musical tone of a specific tone pitch when it is struck with being supported at the first and second supported portions thereof.
With this construction, it is easy to reduce the entire length and width of the sounding member in the keyboard-type percussion instrument, making it possible to increase the degree of freedom in designing the sounding member.
Preferably, the keyboard-type percussion instrument further includes a plurality of percussion units arranged to respectively correspond to the plurality of keys and the plurality of sounding members, each percussion unit striking a corresponding one of the plurality of sounding members when driven by a depressing operation of a corresponding one of the plurality of keys, wherein a relative position between each of the plurality of keys and a corresponding one of the plurality of sounding members in the direction in which the plurality of keys are arranged can be varied, and when the relative position is varied, a correspondence relationship between corresponding ones of the plurality of sounding members and the percussion units changes, and that sounding member which can be struck by the percussion unit driven by the key depressing operation is thereby made different from that one which can be struck by the driven percussion unit before the relative position is varied.
With this construction, key transposition can be implemented in the acoustic sounding keyboard-type percussion instrument, making it possible to provide a variety of musical performances.
Preferably, the plurality of percussion units are configured to move in unison with the plurality of keys in the direction in which the plurality of keys are arranged.
With this construction, a mechanism for shift alteration in a grand piano can be applied, for instance, making it possible to implement the key transposition with a simple construction.
Preferably, the keyboard-type percussion instrument further includes a resonance box disposed fixedly with respect to and closely to the plurality of sounding members, wherein the plurality of sounding members and the resonance box are configured to move in unison in the direction in which the plurality of keys are arranged.
With this construction, the key transposition can be implemented, while maintaining satisfactory sounding capability of sounding members.
To attain the second object, according to a fifth aspect of the present invention, there is provided a keyboard-type percussion instrument, comprising a plurality of keys that constitute a keyboard, and a tone generator unit including a plurality of sounding members and a resonance box having a plurality of resonance chambers corresponding to respective ones of the plurality of sounding members, wherein the plurality of sounding members of the tone generator unit are arranged in a direction in which the plurality of keys are arranged, and each of the plurality of sounding members vibrates to generate a musical tone of a specific tone pitch when it is struck, the plurality of resonance chambers of the tone generator unit each have an opening side thereof, and the plurality of tone plates are mounted to the resonance box so as to be capable of vibrating, with each of the tone plates located close to the opening side of a corresponding one of the resonance chambers, whereby the resonance box and the plurality of tone plates are formed into one unit.
With this construction, it is possible to increase the ease of replacement of the entire tone generator unit while maintaining a proper positional relationship between the resonance box and the sounding members, making it possible to easily change the tone color of an acoustic keyboard-type percussion instrument.
The above and other objects, features, and advantages of the invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings.
The present invention will now be described in detail below with reference to the drawings showing preferred embodiments thereof.
In the following, the side of the keyboard instrument 10 toward a player will be referred to as the front side, and the left and right directions are determined in reference to the player. A pedal box 11 is provided in a lower part of the keyboard instrument 10, and a damper pedal 12 is extended forwardly from the pedal box 11.
The keyboard instrument 10 is analogous to a celesta in which tone plates formed into a flat plate are used as sounding members. A plurality of tone plates (mentioned later with reference to
As shown in
Action mechanisms 20 are disposed through action brackets on an upper portion of a rear half of the key frame 15. The action brackets 22 and the action mechanisms 20 are arranged to correspond to respective ones of the keys 27, 28. The action mechanisms 20 are the same in construction as those of a grand piano. Atone generator unit UNT, including a wood resonance box 50 and a tone plate group 30G comprised of a plurality of tone plates 30, is disposed above the action mechanisms 20. The tone plates 30 are provided to correspond to respective ones of the keys 27, 28. When any one of the keys 27, 28 is depressed, a corresponding hammer 23 is pivoted upward and then a hammer felt 24 strikes a corresponding tone plate 30, which vibrates and generates a musical tone that resonates in the resonance box 50. The key bed 14 disposed below the action mechanisms 20 is formed with sound output ports 14a.
A plurality of pivotal members 64 are provided above rear ends of the keys 27, 28 so as to correspond to respective ones of the keys 27, 28, and damper felts 26 are provided on respective ones of damper wires 25 extending from the pivotal members 64 (refer to
As shown in
Next, an explanation will be given of the construction of the tone generator unit UNT.
First, the tone plate group 30G will be explained. The tone plate group 30G is comprised of tone plates 30 that are equal in number to the keys. Each of the tone plates 30 vibrates when struck by the corresponding hammer felt 24 and generates a musical tone of a specific tone pitch. The tone plates 30 are different in shape such as the entire length or the like from one another (refer to
As shown in
The supporting holes 36, 37 of each tone plate 30 are provided in positions at which vibration nodes can be formed, and therefore, the tone plate 30 effectively generates a musical tone when caused to vibrate in a state where the tone plate 30 is supported at the supporting holes 36, 37. A longitudinally central portion of the tone plate 30 is a portion where a vibration antinode can be formed (hereinafter referred to as the “antinode portion 31”). The center of the antinode portion 31 is located at a position corresponding to the antinode center of vibration (hereinafter referred to as the “antinode center 31P”). The tone plate 30 has its lower surface that is flat. The front and rear portions of the tone plate 30 project upward and are formed to be thick, whereby these portions constitute first and second mass concentrating portions 32, 33 on which the mass of the tone plate concentrates. The provision of the first and second mass concentrating portions 32, 33 makes it possible to shorten the entire length of the tone plate, in particular, the entire length of the tone plate belonging to the low tone pitch range.
As viewed in the vertical direction (thickness direction), the antinode portion 31 of the tone plate 30 is concave upward and made thinner than the first and second mass concentrating portions 32, 33. First and second thinner portions 34, 35 which are thinner in thickness than the antinode portion 31 are provided between the antinode portion 31 and the first mass concentrating portion 32 and between the antinode portion 31 and the second mass concentrating portion 33.
The resonance box 50 of the tone generator unit UNT is comprised of the low-pitch range portion 50A, a mid-pitch range portion 50B, and a high-pitch range portion 50C that are arranged in the mentioned order as seen from the low-pitch side (refer to
The tone plates 30 are each made of a single material such as aluminum, aluminum allow, or steel, and formed into one piece. In fabricating the tone plate, an elongated member of a single material which is rectangular in cross section (an unmachined member 38 shown in
Generally in a celesta, tone plates for higher pitch sound may be shorter in length. As compared to tone plates 30 belonging to the low-pitch range portion 50A, tone plates 30 belonging to the mid- and high-pitch range portions 50B, 50C may be thinner in thickness of the first and second mass concentrating portions 32, 33 (refer to
The fastener 40 is made of metal or the like, and as shown in
In mounting the tone plate group 30G to the resonance box 50, the tone plates 30 forming the tone plate group 30G are first brought together using the coupling cord 44. For example, the tone plates 30 are arranged in the order of tone pitch, and the coupling cord 44 is inserted into the supporting holes 36, 37 of the tone plates 30 (the coupling cord 44 is looped counterclockwise from the lower left side of the tone plates 30 in the example shown in
More specifically, the coupling cord 44 is sequentially inserted through the front supporting holes 36 of the tone plates 30 in the order of tone pitch from the front supporting hole 36 of the tone plate 30 for the lowest pitch. After inserted through the front supporting hole 36 of the tone plate 30 for the highest pitch, the coupling cord 44 is sequentially inserted through the rear supporting holes 37 of the tone plates 30 in the order of tone pitch from the rear supporting hole 37 of the tone plate 30 for the highest pitch. Finally, the both ends of the coupling cord 44 are tied together at a location on the left of the tone plate 30 for the lowest pitch. At any location the both ends of the coupling cord 44 may be tied together. Two or more cords may be used, which are tied together to form a single coupling cord 44.
As shown in
In order to mount the tone plate group 30, into which the tone plates 30 are tied together by the coupling cord 44, to the resonance box 50, the resonance box 50 is placed up side down, for example, and the pins 41 of the fasteners 40 are inserted into the positioning holes of the front and rear common walls 51, 52 of the resonance box 50 and then pressed into the positioning holes using a tool such as a hammer. The above operation is performed for all the fasteners. Subsequently, the tone plate group 30G is placed on the lower surfaces of the front and rear common walls 51, 52 of the resonance box 50, and the coupling cord 44 is engaged with the cord receiving portions 43 of the fasteners 40 at locations between the tone plates 30. Thereafter, the upside-down resonance box 50 is reversed to a normal state, whereby the tone plate group 30G is held by the resonance box 50 through the coupling cord 44 so as to be suspended therefrom, as shown in
In the tone generator unit UNT, the antinode portions 31 of the tone plates 30 are disposed close to the openings formed in (the lower side of) corresponding ones of a plurality of resonance chambers (mentioned later) of the resonance box 50 so as to be capable of vibrating independently of one another. The distance between adjacent ones of the tone plates 30 is temporarily determined by the thickness of corresponding fasteners 40, and thus the pins 41 of the fasteners 40 can easily be positioned in alignment with the positioning holes, making it easy to perform the required operation. As shown in
As shown in
As shown in
As shown in
As shown in
The inclined plates 54, 55 are each formed by a flat plate that extends in the vertical direction of the resonance box 50. The inclined plates 54 extend parallel to one another, and the inclined plates 55 also extend parallel to one another. Since the inclined plates 54, 55 are basically the same in construction and function from one another, the construction of the inclined plate 55 and the resonance chamber RM2 in the mid-pitch range portion 50B will mainly be explained in the following.
In the tone generator unit UNT, the center positions of the hammer felts 24 (refer to
As shown in
In general, if too small in width, each resonance chamber of the resonance box cannot achieve a satisfactory resonance function. The resonance chambers RM2-1, RM2-2 of this embodiment are each ensured to have a sufficient width in the direction in which the keys are arranged, whereby satisfactory resonance can be realized. In addition, the tone plates 30 that are the same in number to the keys 27 and 28 are arranged within the same width as the total width of the keys in the direction of the array of these keys, and the total width of two tone plates 30 is enough to provide two resonance chambers RM2. As a result, unlike the prior art, it is unnecessary to divide the action mechanisms 20 and the tone plates 30 into two stages for the ordinarily-constructed keyboard KB, and thus they can be constructed into a single stage structure.
The inclined plate 54 in the low-pitch range portion 50A has basically the same construction as the inclined plate 55 in the mid-pitch range portion 50B although these inclined plates 54, 55 are different in angle of inclination and in length (refer to
According to the present embodiment, the tone plates 30 belonging to the low-pitch range portion 50A are each provided with the first and second mass concentrating portions 32, 33 at its parts closer to the front and rear ends thereof with respect the supporting holes 36, 37, and the first and second thinner portions 34, 35 respectively extending between the antinode portion 31 and the first and second mass concentrating portions 32, 33, and are made of a single material (refer to
The tone plates 30 can easily be fabricated by removing, from one direction, that part of an unmachined member 38 which is on one side of the unmachined member as viewed in the thickness direction, wherein the unmachined member 38 is an elongated member that is rectangular in cross section and made of a single material. Thus, it is easy to fabricate the tone plates 30 and make the tone plates 30 for generating different tone pitches have the same width. In the tone generation unit UNT, the number of types of tone plate width can be reduced to three.
According to the present embodiment, moreover, the plurality of tone plates 30 are each mounted for vibration to the resonance box 50 at a location close to the opening of the corresponding resonance chamber of the resonance box 50, whereby the resonance box 50 and the tone plates 30 are unified into the tone generation unit UNT. Thus, it is easy to replace the tone generation unit UNT by a new tone generation unit where an appropriate positional relation is also retained between the resonance box 50 and the tone plates 30. For example, replacement to a new tone generation unit that is different in construction of tone plates and/or resonance box makes it possible to easily change tone colors even in the acoustic tone plate percussion instrument. In addition, such easy replacement of tone generation units UNT makes it easy to perform maintenance of the tone plate group 30G and/or the resonance box 50.
Moreover, the plurality of tone plates 30 are collectively held for vibration by the coupling cord 44, and the coupling cord 44 is mounted to the resonance box 50 by means of the plurality of fasteners 40. In particular, the tone plates 30 are made thick at locations where vibration nodes are formed, which makes it possible to form the supporting holes 36, 37 in the tone plates 30 so as not to extend in the vertical direction but extend in the direction in which the keys are arranged. Since the supporting holes 36, 37 extend in the direction of array of the keys, the tone plates 30 constituting the tone plate group 30G can be held collectively by the coupling cord 44 in a state where they are suspended from the resonance box 50. This makes it possible to collectively handle the tone plate group 30G and collectively mount and dismount the tone plate group 30G to and from the resonance box 50 for ease of mounting and replacement the tone plates 30. Since the supporting holes 36 and 3 are formed in the tone plates 30 at locations where vibration nodes are formed, these holes do not hinder the tone plates from performing satisfactory sounding.
In mounting the tone plates 30, the distance between adjacent ones of the tone plates 30 is temporarily fixed by the fasteners 40. This makes it easier to mount and replace the tone plates 30.
It is not inevitably necessary to form the supporting holes 36, 37 in the form of through holes so long as the plurality of tone plates can be collectively held by a cord member such as the coupling cord 44. For example, each of these supporting holes may be a groove which is formed into a partial circle in cross section and opens to the lower surface of the tone plate 30. From the view point of achieving the function of collectively holding the plurality of tone plates, the cord used therefor is not necessarily be limited to the coupling cord 44. It should be noted that it is not inevitably necessary to collectively hold all the tone plates, but the tone plate group 30G may be divided into two groups or more, and each of the divided tone plate groups may be held together.
According to the present embodiment, the resonance chambers RM1, RM2 for the low- and mid-pitch range portions 50A, 50B are each ensured to have a sufficient width in the direction of array of the keys, which is equal to or wider than the total width of corresponding two tone plates 30, thereby making it possible to achieve satisfactory resonance. In addition, the resonance chambers RM1, RM2 are so defined as to overlap each other as viewed from front, whereby the resonance box 50 can be constructed to have a shortened length in the direction of array of the keys, while ensuring an appropriate width of each resonance chamber. As a result, the tone plate group 30G and the resonance box 5 of the entire keyboard instrument can be constructed into a single-stage structure.
The keyboard instrument is constructed that the imaginary straight line L1 passes through all the resonance chambers RM1, RM2, and RM3, and the antinode centers 31P (refer to
The resonance chambers RM1, RM2 are defined by the plurality of partition plates 53 through which the front and rear common walls 51, 52 are connected and the inclined plates 54, 55 through which adjacent ones of the partition plates 53 are connected, whereby these resonance chambers can be defined with a simple construction and can be fabricated with ease since in particular the plurality of partition plates 53 extend parallel to one another.
Moreover, unlike the conventional upper and lower two-stage structure, the present embodiment, in which the tone plate group 30G and the resonance box 50 of the entire keyboard instrument can have a single-stage structure, does not require a long coupling rod for transmitting a key-depressing operation to a lower group of percussion units. The single-stage structure is simple in construction and can easily be made light in weight. The tone plates 30 corresponding to the white keys 27 and the tone plates 30 corresponding to the black keys 28 are the same in vertical position, making it easy to balance sounds from the tone plates corresponding to the white and black keys. Furthermore, unlike the upper and lower two-stage structure, sounds output from tone plates 30 are not interrupted by the lower tone plate group, lower percussion unit group, and lower resonance box. Thus, the resultant instrument is simple in construction and light in weight and capable of easily unifying key-operation feelings and of efficiently outputting well-balanced sounds. Besides, the sound output ports 14a are formed in the keybed 14 below the action mechanisms 20, and therefore the tone plates 30 can output sounds directly to the outside, thereby enhancing the sound output efficiency.
In the following, a second embodiment of the present invention will be explained. As compared to the first embodiment, the second embodiment differs in the construction of the resonance box 50 of the tone generator unit UNT, but is the same in other respects.
In the first embodiment, the plurality of partition plates 53 in the low- and mid-pitch range portions 50A, 50B are each connected at its both ends with the front and rear common walls 51, 52. On the contrary, in the second embodiment, there are provided a plurality of partition plates 65 whose length is as large as about the half of the length of the partition plates 53. These partition plates 65 are connected at their one ends with either the first or second common wall 51 or 52, as shown in
In the first embodiment, adjacent ones of the partition plates 53 are connected to each other by the inclined plates 54, 55. In the second embodiment, closely arranged two partition plates 65 in the low- and mid-pitch range portions 50A, 50B have other ends (which are not connected to either the front or rear common wall 51 or 52) thereof connected to each other through an inclined plate 66, as shown in
Also in the resonance box 50 shown in
According to the present embodiment, effects which are the same as those attained by the first embodiment can be attained. Furthermore, the antinode center 31P of each of the tone plates 30 is positioned at the center of the corresponding resonance chamber RM4 in the direction of array of the keys, and therefore, the second embodiment is more advantageous than the first embodiment in achieving satisfactory resonance.
In order to only ensure an appropriate width of each resonance chamber in the low- and mid-pitch range portions 50A, 50B to realize satisfactory resonance as well as to realize a single-stage structure of the tone plate group and the resonance box for the entire musical instrument, it is enough if the following conditions are satisfied. Specifically, each of the plurality of resonance chambers must overlap another resonance chamber as seen in plan view, and the maximum width of each resonance chamber in the direction in which the tone plates are arranged must be equal to or larger than the total width of two tone plates corresponding thereto. The type of a material to construct respective portions of the resonance box 50 is not limited to wood. For example, the partition plates and the inclined plates disposed between the front and rear common walls may be made of a resin and may integrally be formed so as to construct the plurality of resonance chambers. Furthermore, the partition plates and the inclined plates may be formed integrally with the front and rear common walls 51, 52 into meshes each of which constitutes one resonance chamber.
In the following, modifications of the resonance box are shown, each of which may be adopted, if necessary, although they are inferior in effect to the first and second embodiments.
As shown by way of example in
As shown in
As shown in
It should be noted that the modification shown in
In the following, a third embodiment of the present invention will be explained. In the third embodiment, the keyboard KB and the action mechanisms 20 are made variable in position in the direction of array of the keys with respect to the tone generator unit UNT. The third embodiment is the same (including the tone generator unit UNT) in construction as the first embodiment, expect for mechanisms for making the keyboard KB and the action mechanisms 20 movable.
In addition to the damper pedal 12, a key transposition pedal 81 is provided in a lower portion of the keyboard instrument 100. A coupling rod 82 is coupled to the key transposition pedal 81. An L-shaped link 84 is provided for clockwise pivotal motion around a pivot shaft 85 that is provided in the main body of the keyboard instrument 100. One end of the L-shaped link 84 is coupled to the coupling rod 82 for pivotal motion around a pivot shaft 83. Further, a pressing member 86 for driving the support 115 in the left-to-right direction is provided in the vicinity of a right side of the support 115. The support is always urged toward the left by means of an urging member such as a spring, not shown, which is provided in a side plate 18R, and another end of the L-shaped link 84 is in contact with the pressing member 86.
Although not illustrated, the tone generator unit UNT is provided with the tone plates 30 that are larger in number than the total number of the white and black keys 27, 28 in the keyboard action unit KACT so as to correspond to the tone generation range that varies according to key transposition range.
In the above construction, when the key transposition pedal 81 is stepped on, the coupling rod 82 is moved upward to rotate the L-shaped link 84 clockwise in
According to the present embodiment, the key transposition can be made in the percussion instrument that acoustically generates sounds, making it possible to provide a variety in performance form. Since the keyboard KB and the action mechanisms 20 are moved together, a mechanism for shift alteration in a grand piano can be applied, making it possible to carry out the key transposition with a simple construction. Besides, satisfactory resonance of a musical tone generated by each tone plate 30 can still be attained since the correspondence relationship between the tone plates 30 and the resonance chambers is fixed.
To permit the key transposition, it is enough to construct the keyboard action unit KACT and the tone generator unit UNT so that the relative position therebetween can be varied. Instead of the keyboard action unit KACT, the tone generator unit UNT may be constructed for sliding motion.
In the present embodiment, as the operating member for driving the pressing member 86, a foot-operated member such as the key transposition pedal 81 is used, but this is not limitative. A hand-operated member may be used. The direction of key transposition in the embodiment is a direction to raise the key, but this is not limitative. Key transposition may be made in a direction in which the key is lowered.
Next, a fourth embodiment of this invention will be explained. Unlike the third embodiment where the key transposition state is sustainable only when the key transposition pedal 81 is being stepped on, the fourth embodiment is so designed that the key transposition state can be maintained. To this end, the fourth embodiment is provided with a mechanism for key transposition different from that of the third embodiment, whereas the construction of the tone generator unit UNT, the keyboard action unit KACT, and the like is the same as that of the third embodiment.
In the mechanism for key transposition, the coupling rod 82, pivot shaft 83, L-shaped link 84, pivot shaft 86, and support 115 have the same construction as those of the third embodiment except for their shapes and lengths. As shown in
Further, a stepped positioning stopper portion 88 is formed in the inner side surface (right side surface) of the side plate 18. The stopper portion 88 is formed into a circular shape, as seen in side view, extending in the direction in which the lever 87 is pivoted (refer to
With the above construction, a user grasps the lever 87 by hand and changes the step 88a to which the lever 87 is to be engaged, where required. For example, when the lever 87 is brought in engagement with the next upper step 88a, the pressing member 86 is urged to the right through the coupling rod 82 and the L-shaped link 84, so that the support 115 is slidingly moved to the right for an amount corresponding to half-tone. To lower the key, it is enough to engage the lever 87 with a lower step 88a.
According to the present embodiment, the same advantages as those attained by the third embodiment can be attained. In addition, key transpositions in both the directions to raise and lower the key can be made, and the resultant key transposition state can be maintained even after the player releases the lever 87.
The key transposition mechanism may be constructed to have both the mechanism of the third embodiment that performs key transposition only when the transposition pedal 81 is ON and the mechanism of the fourth embodiment that maintains the key transposition state.
The present invention is also applicable to glockenspiels.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2005-359315 | Dec 2005 | JP | national |
| 2005-359317 | Dec 2005 | JP | national |
| 2005-359318 | Dec 2005 | JP | national |
