Improvements in and applicable to Pianofortes.
Year: 1894

page_text: Date of Application, 25th July, 1894
Complete Specification Left, 4th Aug., 1894-Accepted, 15th Sept., 1894
PROVISIONAL SPECIFICATION.
Improvements in and applicable to Pianofortes.
I, ERNST EUGEN KAPS, of Dresden, in the Kingdom of Saxony and the
Empire of Germany, Manufacturer of Pianofortes by Appointment to the Royal
Court of Saxony, do hereby declare the nature of this invention to be as
follows:-
This invention refers to improvements in pianofortes and has for its object to
provide pianofortes with a second soundboard in order that the sound produced by
the instrument may be materially increased.
Pianofortes are generally constructed with one soundboard, situate between the
strings and the framing. Attempts have been made to provide pianofortes with
two sound boards, by placing a second soundboard in an oblique position between
the framing and a rear wall provided for that purpose in the casing of the piano-
forte. These attempts have however failed because pianofortes are usually not
provided with a rear wall, but are provided at the back simply with a cover of
woven fibrous or metallic material which allows the sound to pass through and also
prevents dust and insects from entering the instrument.
Now according to my invention a pianoforte is constructed with a rear wall
adapted to form a second soundboard as hereinafter more particularly explained.
By this means I am enabled to construct new pianofortes with two soundboards
and also easily to furnish existing pianofortes with a second soundboard.
I will now proceed to explain with reference to the accompanying drawings how
these objects may be effected. In these drawings,
Fig. 1 is a cross-section on the line x y of Fig. 3 showing so much of a piano-
forte as is necessary to illustrate the application thereto of a second soundboard
according to this invention.
Fig. 2 is a similar section of a separate soundboard and appurtenances; and
Fig. 3 is a back elevation of an ordinary pianoforte with the woven cover
removed.
a is the casing, 6 the keyboard, c the action, d the framing usually of irregular
grid-form as indicated in Fig. 3, e the wrest-plank, f the string-block, h the strings,
and g the ordinary soundboard. These parts may be of any suitable construction,
and form no part of this invention.
In constructing new pianofortes I prolong the casing a at the rear of the
pianoforte by means of two upright lateral walls m, a bottom n, and a sounding-
hood i, and I close the pianoforte at the rear by a second soundboard a'. This
second soundboard may be constructed similarly to the ordinary soundboard of a
thin board provided with ribs a². The soundboard a¹ is, as shown in Fig. 1, rigidly
connected by the parts m and n to the pianoforte. The vibrations of the sound-
board g will be imparted through the apertures of the framing d to the
soundboard a' and the sound thus increased will issue from the pianoforte through
the hood i.
In order to furnish existing pianofortes with two soundboards, I construct a
frame of lateral walls m (Fig. 2), a bottom n, and a hood i; and I close this
frame at its rear with the soundboard a¹. The frame and soundboard and its
appurtenances thus constructed may now be attached by any suitable means
e.g. hooks or bolts-to the rear of a pianoforte having no rear wall.
Although I have just stated that the construction of soundboard described with
reference to Fig. 2 is suitable for application to existing pianofortes this con-
struction may also be employed for new pianofortes, so as to enable the additional

page_text: soundboard to be removed if desired in order that the instrument may be used with
one soundboard only.
Experience has shewn that, when a pianoforte is provided with a second sound-
board as hereinbefore described, in order that the sound may develop well and
issue satisfactorily through the hood i and that the full co-operation of the second
soundboard may be secured, it is advisable that all other apertures in the pianoforte
be closed. The ordinary soundboard g is, as is well known, usually provided with
a number of holes to allow of the passage therethrough of iron strengthening-bolts,
and these holes are usually made of such diameter as to prevent contact of the
soundboard with the bolts. For the purpose just above mentioned, close these
holes by fixing discs of soft leather or other suitable material on the said board,
and providing the said discs with central holes for the bolts to pass through. By
this means I close the holes in the soundboard without creating direct contact
between the wood and the iron, the said leather discs acting in this case as dampers
for preventing the sound from passing, so that the full sound of the pianoforte is
directed towards the second soundboard, and is increased by the vibration of the
latter.
1004
F. WISE HOWORTH,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in and applicable to Pianofortes.
1, ERNST EUGEN KAPS, of Dresden, in the Kingdom of Saxony and the
Empire of Germany, Manufacturer of Pianofortes by Appointment to the Royal
Court of Saxony, do hereby declare the nature of this invention and in what
manner the same is to be performed to be particularly described and ascertained
in and by the following statement :-
This invention refers to improvements in pianofortes and has for its object to
provide pianofortes with a second soundboard in order that the sound produced by
the instrument may be materially increased.
Pianofortes are generally constructed with one soundboard, situate between the
strings and the framing. Attempts have been made to provide pianofortes with
two soundboards, by placing a second soundboard in an oblique position between
the framing and a rear wall provided for that purpose in the casing of the piano-
forte. These attempts have however failed because pianofortes are usually not
provided with a rear wall, but are provided at the back simply with a cover of
woven fibrous or metallic material which allows the sound to pass through and
also prevents dust and insects from entering the instrument.
Now according to my invention a pianoforte is constructed with a rear wall
adapted to form a second sound board as hereinafter more particularly explained.
By this means I am enabled to construct new pianofortes with two soundboards
and also easily to furnish existing pianofortes with a second soundboard.
I will now proceed to explain with reference to the drawings filed with my
Provisional Specification how these objects may be effected. In these drawings,
Fig. 1 is a cross section on the line y of Fig. 3 showing so much of a
pianoforte as is necessary to illustrate the application thereto of a second sound-
board according to this invention.
Fig. 2 is a similar section of a separate soundboard and appurtenances; and
Fig. 3 is a back elevation of an ordinary pianoforte with the woven cover
removed.
a is the casing, 6 the keyboard, c the action, d the framing usually of irregular
grid-form as indicated in Fig. 3, e the wrest-plank, f the string-block, h the strings,

page_text: g
and 9 the ordinary soundboard. These parts may be of any suitable construction
and form no part of this invention.
In constructing new pianofortes I prolong the casing a at the rear of the
pianoforte by means of two upright lateral walls m, a bottom n, and a sounding-
hood i, and I close the pianoforte at the rear by a second soundboard a¹. This
second soundboard may be constructed similarly to the ordinary soundboard of a
thin board provided with ribs a². The soundboard a¹ is, as shown in Fig. 1,
rigidly connected by the parts m and n to the pianoforte. The vibrations of the
Boundboard g will be imparted through the apertures of the framing d to the
soundboard a¹ and the sound thus increased will issue from the pianoforte through
the hood i.
In order to furnish existing pianofortes with two soundboards, I construct a
frame of lateral walls m (Fig. 2) a bottom n, and a hood i; and I close this frame
at its rear with the soundboard a¹. The frame and soundboard and its
appurtenances thus constructed may now be attached by any suitable means
-e.g. hooks or bolts-to the rear of a pianoforte having no rear wall.
Although I have just stated that the construction of soundboard described
with reference to Fig. 2 is suitable for application to existing pianofortes this
construction may also be employed for new pianofortes so as to enable the
additional soundboard to be removed if desired in order that the instrument may
be used with one soundboard only.
Experience has shewn that, when a pianoforte is provided with a second sound-
board as hereinbefore described, in order that the sound may develop well and
issue satisfactorily through the hood i and that the full co-operation of the second
soundboard may be secured, it is advisable that all other apertures in the piano-
forte be closed. The ordinary soundboard g is, as is well known, usually provided
with a number of holes to allow of the passage therethrough of iron bolts and
these holes are usually made of such diameter as to prevent contact of the sound-
board with the bolts. For the purpose just above mentioned, I close these holes
by fixing discs of soft leather or other suitable material on the said board, and
providing the said discs with central holes for the bolts to pass through. By this
means I close the holes in the soundboard without creating direct contact between
the wood and the iron, the said leather discs acting in this case as dampers for
preventing the sound from passing, so that the full sound of the pianoforte is
directed towards the second soundboard, and is increased by the vibration of the
latter.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the saine is to be performed I declare that what I
claim is :-
:-
1. Providing a pianoforte with a second sounding board that forms also the rear
wall of the instrument substantially as herein described.
2. In a pianoforte, the combination with the ordinary sounding board (g) within
the pianoforte casing, of a second sounding board (a) arranged to form the rear
wall of said pianoforte, and a hood (i) through which the sound produced by the
instrument can issue as set forth.
3. A soundboard constructed substantially as hereinbefore described with
reference to and shown in Fig. 2 so that it can be detachably connected to the rear
side of the casing of a pianoforte to serve as a second soundboard therefor as
set forth.
Dated this 4th day of Angust 1894.
F. WISE HOWORTH,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.