IMPROVEMENTS IN PIANOS
Year: 1876

page_text: LETTERS PATENT to Frank Wirth, of the Firm of Wirth and Company, Patent
Agency, of Frankfort-on-the-Main, in the Empire of Germany, for the Inven-
tion of "IMPROVEMENTS IN PIANOS." A communication from Julius Blüthner,
residing at Leipzig, in the Empire of Germany.
PROVISIONAL SPECIFICATION left by the said Frank Wirth at the Office
of the Commissioners of Patents on the 15th March 1876.
FRANK WIRTII, of the Firm of Wirth and Company, Patent Agency, of Frankfort-
on-the-Main, in the Empire of Germany. "IMPROVEMENTS IN PIANOS." A
communication.
The Invention relates to improvements in pianos by which the sound given by
the instrument is increased, and becomes finer than by the pianos heretofor in use,
and consists in a novel construction and arrangement of parts of the piano by which
the single overtones can be damped at the same time as the principal tone.
It is well known that every sound consists of the common action of the partial
tones, and that the more the principal tone appears in combination with the first
harmonious overtones, and the less the disharmonious overtones are allowed to appear,
the greater is the force of the said sound, and the finer and more excellent is its
character. Therefore the increase of the harmonious overtones and especially of the
first overtone has recently been tried by measuring, but it was impossible to realize
because the octaves obtained by the halves of the strings, that is to say, the first
overtones could not be damped. An essential improvement could only be obtained
by adopting an aliquot system, which renders possible the damping of the single
overtones at the same time with the principal tone.
After long trials I have invented a construction and arrangement by which for
the overtones separate strings are stringed. But by carrying out this Invention in
practice there were extraordinary difficulties to be overcome, in the first place the
distance was to be calculated in which the strings for the first overtone were to be
stringed over the side sets or side choirs. For this purpose many trials with the
monochordion were necessary to shew in which distance the string tuned for an
octave higher than the three strings of the side sets or side choirs could vibrate in
common with the principal tone in such manner that the combination of the
principal tone and the octave would appear as one sole tone, and the after effect of

page_text: the sound would appear as a fine decrescendo. After having stated the distance the
whole construction of the pianoforte must with reference to the greater quantity of
strings wholly be altered; in consequence whereof the Invention is put into
practice in the following manner:-
First. The back claviary has been enlarged.
Second. The tuning post has got another form for allowing the same to support
the screws for a side set of 4 to 6 strings instead of such one of only 3 strings.
Third. The agrass or claps are arranged in a wholly new manner for obtaining
proper proportions of vibration.
Fourth. For the lower bass strings a new bridge has been constructed for
keeping the said bass strings insulated from the side sets or side choirs which
are provided with overtone strings, and which side sets reach the commencements
of the lower bass strings.
Fifth. The cross arrangement of the overspun bass strings, and the strings of the
middle tone region is dispensed with.
Sixth. A new damping construction has been made by which the overtone strings
can be damped at the same time as the strings for the principal.
I will now proceed to describe the manner in which my Invention is carried into
practice in a piano divided into five plains.
In the third, fourth, and fifth plains are arranged for every tone four or five
screws, of which three are for the principal tone and the others for the overtone.
The strings for the principal tone pass as usual through the agrass or clasps
through the bridge pegs to the bridge of the sound board, and from there to the
attaching pegs.
The overtone strings go through the top back agrass or clasps of the double agrass
or clasps range in the tuning post through the agrass, and from there to the
attaching pegs.
At the overtones downward from the treble two overtone strings are stringed,
which in their agrass or clasps are placed one above the other. From the agrass
the upper spring goes down and is attached on the side of the other one.
The overtones are tuned for an octave higher than the principal tones, and have
half a measure of the latter.
The agrass or clasps of the overtones, are placed on a bridge which from the
middle to the end line is glued on the sound board. The front part on which the
agrass or clasps are screwed is free in order that the sounding board is allowed to
vibrate freely and completely.
In the fifth plain the aforesaid bridge is united with the bridge of the sounding
board, and the overtone sides are placed to the principle tone sides in total
measure. By this means the increase and prolongation of the tone is equally
obtained, but the shrill and jar ring sound is avoided, which would be unavoidable
if the octave would sound with these high treble tones.
The first sound board bridge is for the overspun strings, and the latter are placed
freely and do not cross other strings.
The second sound board bridge supports the strings in the second plain, which go
over the strings of the third bridge and cross them in consequence.
The third bridge supporting the strings of the other tones goes through the
second, third, fourth, and fifth plains, and reaches also to the first plain. In the
second plain the third bridge goes below the strings of the second bridge.
A suitable damper is provided in the third, fourth, and fifth plains with double
damping cones for damping simultaneously the principal and the overtone.
For effecting a more easy vibration of the overtones thinner strings are used for
the upper tones than for the corresponding principal tones. By this system the
strings placed over the strings of the principal tone can also in the manner of the
combination tones be stringed an octave lower or three strings in triple accord, or
according to the succession of the overtones octave, duodecime, and the like. In
general this idea can be varied in unlimited manner.
The aliquot system is applicable to all construction of pianofortes.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Frank Wirth in the Great Seal Patent Office on the 20th June 1870.
FRANK WIRTH, of the Firm of Wirth and Company, Patent Agency, of Frankfort-
on-the-Main, in the Empire of Germany. "IMPROVEMENTS IN PIANOS." A com-
munication from Julius Blüthner, residing at Leipzig, in the Empire of Germany,
This Invention relates to improvements in pianos by which the sound given by
the instrument is increased and becomes finer than that of the pianos heretofore
in use.
The said Invention consists in a novel construction and arrangement of
parts of the piano by which the single overtones can be damped at the same
time as the principal tone.
It is well known that every sound consists of the common action of the partial
tones, and that the more the principal tone appears in combination with the first
harmonious overtones, and the less the unharmonious overtones are heard the
greater is the force of the said sound and the finer and more excellent is its
character. Therefore the increase of the harmonious overtones and especially of
the first overtone has recently been attempted by measuring, but it has been
found impossible to realise because the octaves obtained by the halves of the string,
that is to say, the first overtone could not be damped. An essential improvement
could only be obtained by adopting au aliquot system which renders possible the
damping of the single overtones at the same time as the principal tone.
After numerous.trials I have Invented a construction and arrangement by which
separate strings are provided for the overtones. In carrying this Invention into
practice many difficulties have to be overcome. In the first place it was necessary to
calculate the distance in which the strings for the first overtone were to be stringed
over the side sets or side choirs. For this purpose many trials with the
monochordion were necessary to the distance the string tuned for an octave higher
than the three strings of the side sets or side choirs could vibrate in common with
the principal tone in such manner that the combination of the principal tone and
the octave would appear as one tone, and the after effect of the sound would appear
as a fine decrescendo. After having stated the distance the whole construction of
the pianoforte had with reference to the greater quantity of strings to be completely
changed; in consequence whereof this Invention is carried into practice in the
following manner :-
First. The back claviary has been enlarged.
Second. The tuning post has another form for allowing the same to support the
screws for a side set of 4 to 6 strings instead of only 3 strings.
Third. The agrafes or clasps are arranged in a novel manner for obtaining proper
proportions of vibration.
Fourth. For the lower bass strings a new bridge has been constructed for
keeping the said bass strings insulated from the side sets or side choirs, which are
provided with overtone strings and which side sets reach the commencements of the
lower bass strings.
Fifth. The cross arrangement of the overspun bass strings and the strings of the
middle tone region are dispensed with.
Sixth. A new damping construction has been made by which the overtone strings
can be damped at the same time as the strings for the principal tones.
DESCRIPTION An TUR DRAWING

page_text: In the III., IV., and V., plains are arranged at A for every tone, 4 or 5 screws, of
which 3 are for the principal tone and the others for the overtone. The strings for
the principal tone pass as usual through the agrass or clasps at B through the
bridge pegs to the bridge of the sound board, and thence to the attachment pegs
or pins.
.
The overtone strings pass through the top back agrass or clasps at B of the
double agrafes or clasps range in the tuning post through the agrafes at C, and
thence to the attachment pegs at D.
At the overtones downward from the treble are arranged two overtone strings,
which in their agrafes or clasps are placed one above the other (see Drawing,
Sheet 2). From the upper string passes down and it is attached to the side of
the other one at D. The overtones are tuned for an octave higher than the
principal tones, and have half a measure of the latter.
The agrafes or clasps of the overtones at C are placed on the bridge G, which from
the middle (represented by dotted line) to the end line is glued on the sound board.
The front part on which the agrass or clasps are screwed is free in order that the
sounding board may vibrate freely and completely.
In the fifth plain the bridge G is united with the bridge of the sounding board,
and the overtone sides are placed to the principal tone sides in total measure. By
this means the increase and prolongation of the tone is equally obtained, but the
shrill and jarring sound which would be unavoidable if the octave should sound
with these high treble tones is avoided.
The sound board bridge 1 is for the overspun strings, and the latter are free and
do not cross other strings.
The sound board bridge 2 supports the strings of the bridge 3 and cross them.
The bridge 3 supporting the strings of the other tones extends through the plains
II., III., IV., and V., and reaches also to 1. In the second plain the bridge 3
passes below the strings of the bridge 2.
F is the damper which is provided in the III., IV., and V. plains with double
damping cones for damping simultaneously the principal and the over tone. In the
sectional view of the damper (Sheet II.), the five points represent the position of the
strings. For effecting a more easy vibration of the overtones thinner strings are
used for the upper tones than for the corresponding principal tones.
By this Invention the strings placed over the strings of the principal tone can
also in the manner of the combination tones be stringed an octave lower, or with
three strings in triple accord or according to the succession of the overtones (octave,
duodecime, and so on). And this arrangemement may be varied in an unlimited
For the tuning process the proportion shown in the Drawings and above
specified is the most suitable, because the strings can easily be put on, removed, or
taken out without causing the tuner any trouble or confusion.
manner.
The aliquot arrangement is applicable to all constructions of pianofortes.
In the present instance the damping is effected from above, but damping from
below may also be adopted.
Having thus fully described the said Invention as communicated to me, and the
manner of performing the same, I wish it understood that I claim the improvements 4
in pianos, as herein above described.
In witness whereof, I, the said Frank Wirth have hereunto set my hand and
seal, this Seventeenth day of June, in the year of our Lord One thousand
eight hundred and seventy-six.