USOO5686679A

United States Patent 19 11 Patent Number: 5,686,679

Nakano et al. 45 Date of Patent: Nov. 11, 1997
54 PERCUSSION INSTRUMENT WITH TONE 1838,502 12/1931 Schluter 84403
BARS FOR EXACTLY GENERATING TONES 2,133,712 10/1938 Musser .. 84403
ONASCALE 2,655,069 10/1953 Marshall 84.404
2,703,504 3/1955 Rowe ... 34/402
(75) Inventors: Minoru Nakano; Hiroaki Ohmuro, 3.013,461 12/1961 Kunz 84.402
both of Shizuoka, Japan 5,198,602 3/1993 Roper. ... 34/403
FOREIGN PATENT DOCUMENTS
73 Assignee: Yamaha Corporation, Japan
60-159894 8/1985 Japan.
21 Appl. No.: 588,065 Primary Examiner-Cassandra C. Spyrou
22 Fled: Jan. 16, 1996 Assistant Examiner-Shih-yung Hsieh
Attorney Agent, or Firm-Ostrolenk, Faber, Gerb & Soffen,
30 Foreign Application Priority Data LLP
Jan. 20, 1995 JP Japan . ........... 7-007674 57 ABSTRACT
51 Int, C. ... GOD 1308 A plurality of metal bars of a vibraphone are regulated such
(52) U.S. C. .......................... ... 84/.402; 84,403 that the first-order to third-order vibration approximate to
58 Field of Search ............................ 84.1402, 403, 404, the frequency ratio of 1:4:8 by using recesses formed in the
84/410, 102 central portion of the metal bar and the end portions on both
sides of the central portion, and a player can make the metal
56 References Cited bars generate tones exactly on a scale so as to harmonize
with one another.
U.S. PATENT DOCUMENTS
1632,751 6/1927 Winterhoff .............................. 84403 17 Claims, 11 Drawing Sheets
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U.S. Patent Nov. 11, 1997 Sheet 10 of 11 5,686,679
U.S. Patent Nov. 11, 1997 Sheet 11 of 11 5,686,679
 5,686,679
1. 2
PERCUSSON INSTRUMENT WITH TONE percussion is of definite pitch or indefinite pitch. The
BARS FOR EXACTLY GENERATING TONES xylophone, the glockenspiel, the vibraphone, the marimba
ONASCALE and kettledrums (or timpani) are of the percussion of the
definite pitch, and other drums, a triangle and a gong are
FELD OF THE INVENTON examples of the percussion of the indefinite pitch. A sound
This invention relates to a percussion instrument and, generated by the percussion of the indefinite pitch is spread
more particularly, to a percussion instrument having tone over a wide frequency range. Although a listener feels the
plates for exactly generating tones on a scale. sound high or low on the basis of strong frequency
components, it is impossible to identify the pitch of the
DESCRIPTION OF THE RELATED ART 10 sound. Therefore, the sound generated by the percussion of
the indefinite pitch does not fall under the definition of the
Axylophone, a glockenspiel, a vibraphone and a marimba tone, and is the intermediate zone between the tone and the
are classified into the percussion instrument of definite pitch, unpitched sound.
and a plurality of slabs or sound bars are arranged in the The kettledrum is tuned to a definite pitch by changing the
percussion instrument. The slabs or the sound bars are s tension exerted on the skin along the rim, and the sound
formed of wood or metal, and are usually supported by felt generated by the kettledrum has a vibration pitches close to
members or strings over a frame. While a player is selec the harmonic series.
tively striking the sound bars with mallets, the sound bars The sound bars of the glockenspiel are equal in cross
vibrate, and generate the tones. section, and are only different in length. The length of the
The vibrations of a sound bar are broken down into 20 sound bar mainly regulates the fundamental vibration, and,
longitudinal vibration components, transverse vibration accordingly, determines the pitch of the tone. However, the
components and torsional vibration components. The trans frequency ratios of the second-order to fourth-order vibra
verse vibration components contain transverse vibrations in tions to the fundamental vibration are 2.765, 5.404, 8,933,
the vertical plane and transverse vibrations in the horizontal and the high-order vibrations are not the multiples of the
plane. When the sound bar is designed, the designer mainly 25 fundamental vibrations. Although the sounds generated by
takes the transverse vibrations in the vertical plane into the glockenspiel are closer to the tone than the sounds
account, and tunes the sound bars. generated by the percussion of the indefinite pitch, the
FIG. 1 illustrates the vibrations generated in a sound bar sounds do not fall under the strict definition of the tone. The
upon an impact with a mallet. Plots fo stands for the other percussion instruments of the definite pitch such as the
first-order or fundamental vibration, and the second-order 30 xylophone and the marimba also do not generate the sound
and the third-order vibrations are represented by plotsf1 and falling under the strict definition of the tone.
f2, respectively. However, the vibrations higher than the In this situation, it is getting stronger and stronger that the
third-order vibration are deleted from FIG. 1. These high music world requests the percussion instruments to generate
order vibrations affect the timbre of the tone. The first-order the tones. Manufacturers of the percussion instruments have
vibration to high-order vibrations are hereinbelow referred 35 improved the percussion instruments. For example, Japa
to as "first-order vibration mode", "the second-order vibra nese Patent Publication of Unexamined Application No.
tion mode", "the third-order vibration mode" and so forth. 60-1598.94 discloses sound bars varied in cross section so as
A musical instrument has various families, and the sounds to make the frequency ratio of each vibration mode an
generated by the families are largely broken down into a integer.
tone and an unpitched sound. The tone is defined as "vibra FIGS. 2A and 2B illustrate a sound bar 1 incorporated in
tions consisting of the fundamental frequency and harmon a marimba or a vibraphone, and the prior art sound bar 1 has
ics thereof", and a listener easily discriminates the funda side portions 1a and 1b thicker than a central portion 1c
mental pitch of the tone. The unpitched sound does not fall therebetween. Holes 1d and 1e are formed in the side
under the definition of the tone. portions 1a and 1b, respectively, and strings (not shown)
A string instrument generates the sounds through vibra
45 pass through the holes 1d and 1e so as to support the sound
tions of the strings, and the cross section of the string is bar 1. The prior art sound bar 1 is tuned in such a manner as
approximated to zero. For this reason, the high-order har to have the frequency ratio of the first-order to third-order
vibration modes is 1:4:10.
monics have respective frequencies substantially multiples FIGS. 2C and 2D illustrate a sound bar 2 incorporated in
of the fundamental frequency, and the sounds generated by 50 a xylophone, and the prior art sound bar 2 has straight side
the string instrument fall under the definition of the tone. portions 2a and 2b and a central portion 2c waved twice
A wind instrument such as a clarinet generates a sound, a between the side portions 2a and 2b. Holes 2d and 2e are
harmonic fi of which is given by equation 1. formed in the straight side portions 2a and 2b, and strings
(not shown) also pass through the holes 2d and 2e. The prior
55 art sound bar 2 is tuned in such a manner as to regulate the
where c is the acoustic velocity in the air and iis an integer. frequency ratio of the first-order to third-order vibration
The frequencies of the high-order harmonics are integers of modes to 1:3:6 or 1:3:7. Although there is a possibility that
the fundamental frequency, and the harmonic distortion the frequency of the third-order vibration mode is not tuned,
affects the timbre of the tone. The second-order harmonic the sound bars 1 and 2 shown in FIGS. 2A/2B and 2C/2D
differs from the fundamental frequency by an octave, and the approximate the frequencies to the above ratios. Comparing
third-order harmonic is spaced from the second-order har the sound bar 1 shown in FIGS. 2A and 2B with the sound
monic by fifth. For this reason, the pitches of the sound is bar 2 shown in FIGS. 2C and 2D, the sound bar 1 generates
clearly discriminative by a listener, and the wind instrument the second vibration mode 2' times larger infrequency than
generates the sounds having vibration pitches in the har the first vibration mode, and achieves a kind of consonant.
monic series. 65 However, when it is compared with a string instrument and
On the other hand, the sounds generated by the percussion a wind instrument, the e frequency ratio of 2" where n is 0,
do notfall under the strict definition of the tone. In detail, the 1 and 2, and the vibration modes become close to the
 5,686,679
3 4
harmonic series. However, there is yet room for improve FIG. 8B is a front view showing the sound bar;
ment in consonance and musical interval. FIG. 8C a side view showing the sound bar;
SUMMARY OF THE INVENTON FIG. 9A is a plan view showing a sound bar incorporated
s
in a percussion instrument according to the present inven
It is therefore an important object of the present invention tion;
to provide a percussion which generates sounds consonant FIG.9B is a front view showing the sound bar;
like the string instrument and the wind instrument. FIG. 9C is a side view showing the sound bar;
In accordance with the present invention, there is pro F.G. 10A is a plan view showing a sound bar incorporated
vided a percussion instrument comprising: a plurality of O in a percussion instrument according to the present inven
sound bars respectively assigned notes of a scale, and tion;
generating vibrations when a player beats, the vibrations of FIG. 10B is a front view showing the sound bar;
each of the plurality of sound bars having at least a first
order vibration for mainly impressing the note assigned to FIG. 10C is a side view showing the sound bar;
the aforesaid each of the plurality of sound bars, a second 5 FIG. 11A is a plan view showing a sound bar incorporated
order vibration and a third-order vibration, a frequency ratio in a percussion instrument according to the present inven
of the first-order vibration, the second-order vibration and tion;
the third-order vibration being approximately equal to 1:4:8; FIG. 11B is a front view showing the sound bar; and
and a frame structure supporting the plurality of sound bars, FIG. 11C is a side view showing the sound bar.
and allowing the plurality of sound bars to freely vibrate.
The sound bar may have a central portion formed with a DESCRIPTION OF THE PREFERRED
recess and endportions contiguous to the central portion and EMBOOMENTS
formed with respective recess so as to regulate the frequency First Embodiment
ratio to 1:4:8.
The sound bar may have a central portion formed with a 25
Referring to FIG. 3 of the drawings, a vibraphone
multiple recess and end portions without a recess so as to embodying the present invention largely comprises a frame
regulate the frequency ratio to 1:4:8. structure 10, a plurality of metal bars 11 and a plurality of
resonators 12a and 12b. Although the plurality of metal bars
BRIEF DESCRIPTION OF THE DRAWINGS 11 are laid out on the pattern of a keyboard incorporated in
The features and advantages of the percussion instrument 30 a standard piano, only seven metal bars 11a, 1b, 11c, 11d,
11e, 11f and 11g are mounted on the frame structure 10 in
according to the present invention will be more clearly FIG. 3. In this instance, the plurality of metal bars 11 serve
understood from the following description taken in conjunc as a plurality of sound bars.
tion with the accompanying drawings in which: The frame structure 10 comprises two pairs of lateral bars
FIG. 1 is a graph showing the first-order to third-order 35 10a/10b and 10c/10d, a plurality of pin members 10e, 10f,
vibrations generated by the prior art sound bar; 10g and 10h implanted into the lateral bars 10a to 10d at
FIG. 2A is a front view showing the prior art sound bar intervals, two pairs of braids 10i/10, and 10kd10m spread
incorporated in the marimba or the vibraphone; over the lateral bars 10a to 10d and two pairs of rail
FIG. 2B is a side view showing the prior art sound bar for members 10n/10p and 10g/10rrespectively extending inside
the marimba or the vibraphone; of the two pairs of lateral bars 10a to 10d. The braids 10o to
FIG. 2C is a front view showing the prior art sound bar 10m are respectively associated with the four lines of the pin
incorporated in the xylophone; members 10e to 10h, and pass through the holes formed in
FIG. 2D is a side view showing the prior art sound bar for the associated pin members 10e to 10h. The braids 10i to
the xylophone; 10m make knots (not shown) outside of the outermost pin
45 members 10e to 10h, and the knots do not allow the braids
FIG. 3 is a perspective view showing a vibraphone 10i to 10m to slip out.
according to the present invention; The plurality of metal bars 11 cover a compass for three
FIG. 4A is a plan view showing a metal bar incorporated octaves, by way of example, and notes of a scale are
in the vibraphone; respectively assigned to the plurality of metal bars 11. The
FIG. 4B is a front view showing the metal bar; 50 plurality of metal bars 11 are arranged in two rows over the
FIG. 4C is a side view showing the metal bar; two pairs of lateral bars 10a/10b and 10c/10d, and a player
FIG. 5 is a cross sectional view taken along line A-A of stands in front of the first row including the metal bars 11d
FIG. 3 and showing the structure of the vibraphone; to 11g. The metal bars of the first row generate the natural
FIG. 6A is a plan view showing a sound bar incorporated tones. On the other hand, the metal bars of the second row
in another percussion instrument according to the present 55 generate the other tones usually represented by using sharp
invention or flat. The metal bars 11a to 11c are staggered with respect
FIG. 6B is a front view showing the sound bar; to the metal bars 11d to 11g by half pitch, and each of the
FIG. 6C is a side view showing the sound bar; metal bars 11a to 11c is located between the adjacent two
metal bars 11d/11e, 11e/11 for 11f11g.
FIG. 7A is a plan view showing a sound bar incorporated FIGS. 4A to 4C illustrate one of the metal bars 11. All of
inyet another percussion instrument according to the present the metal bars 11 are similar in configuration. The metal bars
invention; 11 are equal in width to one another, and are different in
FIG. 7B is a front view showing the sound bar; length depending upon the notes assigned thereto. The metal
FIG. 7C is a side view showing the sound bar; bar 11 is a generally rectangular parallelepiped
FIG. 8A is a plan view showing a sound bar incorporated 55 configuration, and is divided into a central portion 11i and
in still another percussion instrument according to the end portions 11j and 11k. Two holes 11m and 11n are
present invention; respectively formed in a boundary between the end portion
 5,686,679
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11j and the central portion 11i and a boundary between the maximum amplitude. In general when a recess is formed in
end portion 11k and the central portion 11 i. a sound bar, the recess has an influence on the frequencies
The braids 10i and 10 respectively pass through the holes of all the vibration modes to some extent. However, the
11m and 11n, and support the metal bars 11 of the first row power of the influence is different among the vibration
over the pair of lateral bars 10a/10b. On the other hand, the modes. If a recess is located in a place where an antinode of
braids 10k and 10m pass through the holes 11m and 11n, and a vibration takes place, the recess widely decreases the
the metal bars 11 of the second row are supported through frequency of the vibration. On the other hand, if a recess is
the braids 10k and 10m by the pin members 10g/10h over the matched with a node of a vibration, the recess slightly
pair of lateral bars 10c/10d. decreases the frequency of the vibration. The recess 11s has
An upper surface 11p is flat, and a player beats the upper O the strongest influence on the first-order vibration. The
second-order vibration is subsequently affected by the recess
surface with a mallet (not shown). The lower surface 11g is 11s, because the adjacent two antinodes takes place in or
partially curved, and forms recesses 11r, 11s and 11t in the around the flat thin sub-portion 11ia. However, the recess
end portion 11j, the central portion 11i and the other end 11s has the least influence on the third-order vibration
portion 11k, respectively. The remaining lower surface 11g among the first-order to third-order vibrations.
is flat between the recesses 11 rand 11s and the recesses 11s 15
Turning back to FIG. 3 of the drawings, the resonators
and 11t, and are substantially parallel to the upper surface 12a and 12b are implemented by metal tubes, and are
11p. The lower surface 11g defining the recesses draws arcs supported beneath the metal bars 11 by the pairs of rails
11ga and 11ab, and a flat sub-surface 11gc and round 10n/10p and 10q/10r (see FIG. 5). When the metal bar 11 is
sub-surfaces 11gd and 11ge form the lower surface 11g beaten, the metal bar 11 vibrates, and the associated reso
defining the recess 11s. The flat sub-surface 11s is substan nator 12a/12b imparts a vibrating sound to the tone.
tially in parallel to the upper surface 11p. The recess 11s Subsequently, description is made on advantages of the
makes the central portion 11i partially thinner than those on metal bar 11 over the sound bar 1 of the prior art vibraphone
both sides thereof, and the part of the central portion 11i shown in FIGS. 2A and 2B.
along the flat sub-surface 11gc is hereinbelow called as a flat In this instance, the frequency ratio of the first-order
central sub-portion 11ia. 25 vibration, the second-order vibration and the third-order
The hole 11m is oblique with respect to side surfaces 11u vibration is regulated to 1:4:8. In other words, the second
and 11y, and the other hole 11n is normal to the side surfaces order vibration is 2 octaves higher than the first-order
11u and 11y. Additionally, the reason why one of the holes vibration, and the third-order vibration is 3 octaves higher
than the first-order vibration. If one of the metal bars 11 is
11m obliquely extends is that the distance between the nodes 30 tuned to A1, the first-order vibration is 442 Hz, and the
N1 and N2is decreased together with the length of the sound second-order vibration and the third-order vibration are
bar depending upon the pitch of the sound. End surfaces 11 w corresponding to A3 two octaves higher than A1 and A4
and 11x are substantially in parallel to each other, and the three octaves higher than A1, respectively. The second-order
peripheries of the end surfaces 11 w and 11x are chamfered. vibration and the third-order vibration emphasizes the note
The direction between the end surfaces is hereinbelow 35 of the first-order vibration, and the vibraphone according to
referred to as "longitudinal direction", and "length” repre the present invention clearly discriminative tones. Thus, the
sents the distance in the longitudinal direction. On the other metal bar 11 generates the first-order vibration to the third
hand, "width" is indicative of the distance between the side order vibration identical in the pitch name with one another,
surfaces 11u and 11 v, and the width is measured in a lateral and the vibrations fall under the strict definition of the tone.
direction of the metal bar 11. As described hereinbefore, the second-order vibration
When a player beats the metal bar 11, vibrations are generated by the prior art sound bar 1 is four times larger in
generated in the metal bar 11, and contains a fundamental or frequency than the first-order vibration, and the third-order
first-order vibration, a second-order vibration and a third vibration is ten times larger in frequency than the first-order
order vibration. The first-order vibration mainly impresses vibration. The frequency ratio of the metal bar 11 is smaller
the note assigned to the metal bar 11 beaten by the player, 45 than that of the prior art sound bar 1, and, accordingly, the
and high-order vibrations, i.e., the second-order vibration, frequency spectrum generated by the metal bar 11 is denser
the third-order vibration and so forth affect the timbre of the
sound. than that of the prior art sound bar 1. In other words, the tone
generated by the prior art sound bar 1 is less consonant with
The antinode of the first-order vibration takes place in the related tones. On the other hand, the tone generated by the
flat central sub-portion 11ia, and the nodes N1 and N2 of the 50 metal bar 11 is highly consonant with related tones. In
first-order vibration take place in the holes 11m and 11n. The general, the consonance takes place through gentle beat due
recesses 11r and 11t are located outside the nodes N1 and to an interference between the frequency components close
N2.
to one another. When the prior art sound bars 1 vibrate for
The frequency ratio of the first-order to the third-order generating a chord, there is a large difference between the
vibrations is regulable by changing the dimensions of the 55 second-order vibration of the higher tone and the third-order
recesses 11 r, 11s and 11t. In detail, as described vibration of the lower tone, and the second-order vibration
hereinbefore, when the rectangular parallelepiped sound bar of the higher tone is seldom interfered with the third-order
is beaten, the frequency ratio of the first-order vibration fo, vibration of the lower tone. As a result, the higher tone and
the second-order vibration f1 and the third-order vibration f2 the lower tone hardly form the chord. On the other hand, the
is 1:2.765:5.404. In order to regulate the frequency ratio to third-order vibration generated by the metal bar 11 is eight
1:4:8, it is necessary to lower the frequency of the first-order times larger in frequency than the first-order vibration.
vibration forelatively to the frequencies of the second-order When related metal bars 11 are beaten for generating a
and third-order vibrations f and f2 and further lower the chord, the second-order vibration of the higher tone is close
frequency of the second-order vibration f1 relatively to the to the third-order vibration of the lower tone, and is liable to
third-order vibration f2. 65 beinterfered with the third-order vibration of the lower tone.
Each of the first-order to third-order vibrations has a node The interference results in gentle beat, and the higher tone
with the minimum amplitude and an antinode with the and the lower tone form the chord.
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Finally, the metal bars 11 form a compass wider than the to 7C, braids pass through the holes 31d and 31e, and the
compass prior art sound bar 1. The standard pitch used in the sound bar 31 floats over a frame structure (not shown).
tuning is A1 at 442 Hz, and the standard frequency analyzer The sound bar 31 has a flat upper surface 31fbeaten with
can measure the frequency until C5 at 4205 Hz. If the a mallet (not shown), and a lower surface 31g is partially
frequency ratio is 1:4:10, the standard frequency analyzer curved so as to form a multiple recess 31h in the central
can regulate until G1 at 417.2 Hz, because the third-order portion 31a. However, the end portions 31b and 31c have
vibration of the next tone exceeds the upper limit of the respective flat lower sub-surface 31ga and 31gh substan
standard frequency analyzer. On the other hand, the metal tially in parallel to the upper surface 31f, and no recess is
bar 11 has the frequency ratio of 1:4:8, and the standard formed in the end portions 31b and 31c.
frequency analyzer can check C2 at 525.6 Hz. Thus, the 10 The lower surface 31g defines the multiple recess 31h as
metal bars 11 provide a wider compass. follows. The lower surface 31g is curved to form an arc
Second Embodiment sub-surface 31gc at the midportion of the sound bar 31, and
FIGS. 6A to 6C of the drawings illustrate a sound bar 21 first flat lower sub-surfaces 31gd and 31ge are contiguous to
incorporated in a percussion instrument embodying the 15
the arc sub-surface 31gc in parallel to the upper surface 31f.
present invention. The sound bar 21 is divided to a central First round sub-surfaces 31gfand 31gg extend between the
portion 21a and endportions 21b and 21c, and holes. 21d and first flat lower sub-surfaces 31gdi31ge and second flat power
21e are formed in the boundary between the endportion 21b sub-surfaces 31gh and 31gi. Second round sub-surfaces 31gj
and the central portion 21a and between the central portion and 31gk connect the second flat lower sub-surfaces 31gh
21a and the endportion 21c. Though not shown in FIGS.6A 20
and 31gi to the flat lower sub-surfaces 31ga and 31gb. The
to 6C, braids pass through the holes. 21d and 21e, and the second flat lower sub-surfaces 31gh/31gi and the second
sound bar 21 floats over a frame structure (not shown). round sub-surfaces 31g.j and 31gk define a shallow recess
The sound bar 21 has a flat upper surface 2fbeaten with 31ha, and the arch sub-surface 31gc defines a deep recess
a mallet (not shown), and a lower surface 21g is partially 31hb. The first flat lower sub-surfaces 31gdi31ge and the
curved so as to form a multiple recess 21h in the central 25
first round sub-surfaces 31gf31gg define an intermediate
portion 21a. However, the end portions 21b and 21c have recess 31.h.c., and the shallow recess 31ha, the intermediate
respective flat lower sub-surface 21ga and 21gb substan recess 31.hc and the deep recess 31hb form in combination
tially in parallel to the upper surface 21f and no recess is the multiple recess 31h.
formed in the end portions 21b and 21c. In this instance, the first-order vibration has the antinode
The lower surface 21g defines the multiple recess 21h as 30
in the thinnest portion defined by the deep recess 31.hb, the
follows. The lower surface 21g is curved to form an arc second-order vibration has the antinodes in the thinner
sub-surface 21gc at the midportion of the sound bar 21, and portion defined by the intermediate recess 31.hc, and the
flat lower sub-surfaces 21gd and 21ge are contiguous to the third-order vibration has antinodes in the thin portion
arc sub-surface 21gc in parallel to the upper surface 21f. defined by the shallow recess31ha. Therefore, the frequency
Round sub-surfaces 21gf and 21gg extend between the flat 35
of the first-order vibration, the frequency of the second-order
lower sub-surface 21gd and the flat lower sub-surface 21ga vibration and the frequency of the third-order vibration are
and between the flat lower sub-surface 21ge and the flat independently regulable by selecting the thicknesses of the
lower sub-surface 21gh. The flat lower sub-surfaces 21gd thinnest, thinner and thin portions, and the frequency ratio is
21ge and the round sub-surfaces 21gf and 21gg define a adjusted to 1:4:8 without a recess of the end portions
shallow recess 21ha, and the arch sub-surface 21gc defines 31b/31c.
a deep recess 21hb. The shallow recess 21ha and the deep The percussion instrument of the second embodiment
recess 21hb form in combination the multiple recess 21h. achieves all of the advantages of the first embodiment.
As described hereinbefore, a vibration changes the fre Fourth Embodiment
quency depending upon the thickness of the sound bar at the FIGS. 8A to 8C illustrate a sound bar 41 incorporated in
antinode. In this instance, the first-order vibration has the 45 still another percussion instrument embodying the present
antinode in the thinnest portion defined by the arc sub invention. The sound bar is divided into a central portion 41a
surface, and the second-order vibration and the third-order and end portions 41b and 41c. The central portion 41a is
vibration have respective antinodes in the central portion similar to the central portion of the second embodiment, and
21a on bode sides of the thinnest portion. Therefore, the surfaces and recesses are labeled with the same references
frequency of the first-order vibration is regulable indepen 50 designating the corresponding surfaces and recesses of the
dently from the second-order and third-order vibrations, and second embodiment without detailed description.
the central portion 21a on both sides of the thinnest portion The endportions 41b and 41c have respective recesses 41i
has strong influence on the second-order vibration rather and 41j. The recesses 41i and 41jhave the same influence of
than the third-order vibration. Thus, the first-order and the vibration characteristics on the sound bar 41 as the
second-order vibrations are independently regulable, and the 55 recesses 11r and 11t, and the frequency ratio is exactly
frequency ratio is adjusted to 1:4:8 without a recess of the regulated to 1:4:8.
end portions 21b/21c. Fifth Embodiment
The percussion instrument of the second embodiment FIGS. 9A to 9C illustrate a sound bar 51 incorporated in
achieves all of the advantages of the first embodiment. a percussion instrument embodying the present invention.
Third Embodiment The sound bar 51 is divided into a central portion 51a and
FIGS. 7A to 7C of the drawings illustrate a sound bar 31 end portions 51b and 51c. The central portion 51a is similar
incorporated in a percussion instrument embodying the to the central portion of the third embodiment, and surfaces
present invention. The sound bar 31 is divided to a central and recesses are labeled with the same references designat
portion 31a and endportions 31b and 31c, and holes 31d and ing the corresponding surfaces and recesses of the third
31e are formed in the boundary between the endportion 31b 65 embodiment without detailed description.
and the central portion 31a and between the central portion The endportions 51b and S1c have respective recesses 51i
31a and the endportion 31c. Though not shown in FIGS. 7A and 51j. The recesses 51i and 51jhave the same influence of
 5,686.679
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the vibration characteristics on the sound bar 51 as the 2. The percussion instrument as set forth in claim 1, in
recesses 11r and 11t, and the frequency ratio is exactly which said each of said plurality of sound bars is divided
regulated to 1:4:8. into a central portion and end portions with respect to nodal
Sixth Embodiment points where nodes of said first-order vibration take place,
FIGS. 10A to 10C illustrates a sound bar 61 incorporated said central portion having a first recess at a central
in a percussion instrument embodying the present invention. sub-portion where an antinode of said first-order vibra
The sound bar 61 is divided into a central portion 61a and tion takes place,
end portions 61b and 61c. The end portions 61b and 61c are each of said end portions having a second recess.
similar to those of the second embodiment, and surfaces of 3. The percussion instrument as set forth in claim 2, in
the end portions are labeled with the same references des 10 which said first recess and the second recesses are open to
ignating the corresponding surfaces of the end portions 11j a lower surface reverse to an upper surface where a player
and 11k without detailed description. beats.
A multiple recesses 61 h is formed in the central portion 4. The percussion instrument as set forth in claim 1, in
61a, and a shallow recess 61 ha and a deep recess 61.hbform which said each of said plurality of sound bars is divided
in combination the multiple recesses 61h. The deep recess into a central portion and end portions with respect to nodal
61hbis defined by the arc sub-surface 21gc, and the shallow 15
points where nodes of said first-order vibration take place,
recess 61 ha is defined by another arc sub-surface 61ga. The said central portion having a multiple recess implemented
radius of curvature of the arc sub-surface 61ga is larger than by a plurality of first recesses nested in one another, the
that of the arc sub-surface 21gc, and no flat surface is deepest recess of said plurality of first recesses being
incorporated in the lower surface defining the central portion
61a. defined by an arc surface in such a manner as to locate
The sixth embodiment achieves all of the advantages of said deepest recess at a certain sub-portion where an
the second embodiment. antinode of said first-order vibration takes place.
Seventh Embodiment 5. The percussion instrument as set forth in claim 4, in
FIGS. 11A to 11C illustrate a sound bar 71 incorporated which said plurality of first recesses further has a shallow
in a percussion instrument embodying the present invention. recess defined by a flat surface contiguous to said arc surface
The sound bar 71 is divided into a central portion 71a and 25 and a round surface extending between said flat surface and
end portions 71b and 71c, and the central portion 71a is surfaces of said end portions.
similar to the central portion 61a of the sixth embodiment. 6. The percussion instrument as set forth in claim 5, in
Surfaces and recesses of the central portion 71a are labeled which said deep recess and said shallow recess are open to
with the same references as those of the sixth embodiment a lower surface reverse to an upper surface where a player
without detailed description. 30 beats.
Recesses 71i and 71j are formed in the end portions 71b 7. The percussion instrument as set forth in claim 5, in
and 71c. Therefore, the frequency ratio is exactly regulated which each of said end portions has a second recess.
to 1:4:8. 8. The percussion instrument as set forth in claim 7, in
As will be appreciated from the foregoing description, the which said deep recess, said shallow recess and the second
recess or the multiple recess of the central portion regulates 35 recesses are open to a lower surface reverse to an upper
the frequencies of the first-order to third-order vibrations, surface where a player beats.
and the recesses of the end portions differently changes the 9. The percussion instrument as set forth in claim 5, in
frequencies of the first-order to third-order vibrations. As a which said plurality of first recesses further has an interme
result, the frequency ratio of the first-order to third-order diate recess formed between said deep recess and said
vibrations is regulated to 1:4:8. The sound bars thus regu shallow recess.
lated generates the tones exactly on the scale, and the tones 10. The percussion instrument as set forth in claim 9, in
of a chord beautifully harmonize with one another, which said deep recess, said shallow recess and said inter
Although particular embodiments of the presentinvention mediate recess are open to a lower surface reverse to an
have been shown and described, it will be obvious to those upper surface where a player beats.
skilled in the art that various changes and modifications may 11. The percussion instrument as set forth in claim 9, in
be made without departing from the spirit and scope of the 45 which each of said end portions has a second recess.
present invention. 12. The percussion instrument as set forth in claim 11, in
For example, the sound bar according to the present which said deep recess, said shallow recess, said interme
invention is available for a percussion instrument of a diate recess and the second recesses are open to a lower
definite pitch such as, for example, a xylophone, a glock surface reverse to an upper surface where a player beats.
enspiel and a marimba. 13. The percussion instrument as set forth in claim 4, in
Moreover, the sound bar may be formed of wood or which said plurality of first recesses further has a shallow
synthetic resin. recess defined by another arc surface contiguous to said arc
What is claimed is: surface.
1. A percussion instrument comprising: 14. The percussion instrument as set forth in claim 13, in
a plurality of sound bars respectively assigned notes of a 55 which said deep recess and said shallow recess are open to
scale, and generating vibrations when a player beats, a lower surface reverse to an upper surface where a player
beats.
the vibrations of each of said plurality of sound bars 15. The percussion instrument as set forth in claim 13, in
having at least a first-order vibration for mainly which each of said end portions has a second recess.
impressing the note assigned to said each of said 16. The percussion instrument as set forth in claim 15, in
plurality of sound bars, a second-order vibration and which said deep recess, said shallow recess and the second
a third-order vibration, recesses are open to a lower surface reverse to an upper
a frequency ratio of said first-order vibration, said surface where a player beats.
second-order vibration and said third-order vibration 17. The percussion instrument as set forth in claim 1,
being equal to 1:4:8; and further comprising a plurality of resonators provided
a frame structure supporting said plurality of sound bars, 65 beneath said plurality of sound bars.
and allowing said plurality of sound bars to freely
vibrate. . . . .