IMPROVEMENTS IN PIANOFORTES
Year: 1882

page_text: LETTERS PATENT to Sam Peppler, of Piccadilly, in the County of Middlesex
and John Carter, of the Town and County of Southampton for an invention
of "IMPROVEMENTS IN PIANOFORTES"
(Void by reason of the Patentee having neglected to file a Specification in
pursuance of the conditions of the Letters Patent.)
PROVISIONAL SPECIFICATION left by the said Sam Peppler and John
Carter at the Office of the Commissioners of Patents on the 22nd May
.1882.
SAM PEPPLER, of Piccadilly, in the County of Middlesex, and JOHN CARTER, of
the Town and County of Southampton "IMPROVEMENTS IN PIANOFORTES
"
The object of our Invention is to increase the volume of sound given out from
pianofortes, and also to improve the quality of the tone of such instruments.
The Invention is equally applicable to vertical and grand pianofortes, that is, to
pianofortes having either a vertical or a horizontal action, and existing instruments
may have the improvements applied to them with but little alteration to existing
parts.
It consists essentially in the application of a sounding chamber in the space
behind the ordinary sounding board.
The depth of this sounding chamber, and the thickness of its walls, will vary.
according to the instrument to which it is to be applied, and will be so pro-
portioned as to give the best possible results, both with regard to the quantity or
volume of sound, and quality of tone. In some cases it would be preferable to
make the back or part of the chamber furthest removed from the sounding board
of smaller dimensions than the part adjoining the sounding board, so as to form
with the surrounding walls a chamber gradually diminshing in size from the front
to the back.

page_text: This chamber will preferably be constructed of hard wood of a suitable thickness
to enable its walls to vibrate under the impulse of the sound waves proceeding
from the sounding board placed behind the wires or strings of the instrument, but
any other sonorous material which is capable of readily responding to such sound
waves, and thereby increasing the volume of sound and enriching its tone might
be employed.
We will now proceed to explain the application of this Invention to pianofortes
of the upright or vertical class, and it will be readily understood that the
description of its application to pianofortes of the horizontal class will differ only
in the position of the parts herein referred to.
It is preferable that the frame over which the wires or strings are stretched in
any suitable manner, shall be made of metal and constructed according to any of
the approved methods adopted in what are known as "iron frame
or "steel
frame" pianofortes, the "wrest planks" being preferably supported at both ends
by metal uprights, secured to the side walls of the outer wooden case of the
instrument. The sounding board placed behind the wires or strings may be of
any suitable construction and material, but instead of occupying the whole of the
space enclosed by the frame, its two side edges will terminate a certain distance
from the sides of the frame, so as to leave "sound holes" or "forte holes" along
the whole length of the sides of the frame, the width of such openings being about
2 inches, but varying according to the size and class of instrument. Or sound
holes" or "forte holes" might be made through the sounding board itself, either in
'addition to those above mentioned or in place of the same.
The shape of the sounding chamber, which is open in front, follows the contour
of the frame, and it is fixed behind the sounding board, so that the latter forms
the front of the chamber, the edges of the chamber butting tightly against the
frame, and forming with the sounding board a kind of closed chamber behind the
wires or strings, with the exception of the "sound holes" or "forte holes" left in
the sounding board.
It will thus be seen that the sounding chamber will fulfil the same functions as
the wooden body of a violin, the vibrations of the wires or strings being
transmitted by the bridge to the sounding board, and the sonorous nature of the
material of which the sounding chamber is constructed, causes the whole of the
chamber, and the air which it contains to vibrate in unison with the wires or
strings, thereby greatly augmenting the sound given out and enriching the tone of
the instrument.
Any of the surrounding walls of the chamber may also be provided with "sound
holes" or "forte holes" covered by valves, either under the control of a separate
pedal or connected to the usual "forte pedal" of the pianoforte, so that the volume
of sound given out may be regulated as desired.
As applied to pianofortes in which the frame over which the wires or strings are
stretched is made of wood, it will be necessary to replace the ordinary wooden
stays inserted between the "wrest planks" to resist the tensional strain of the
wires, by one or more metal stays placed behind the sounding board and attached
to the top and bottom "wrest planks" of the frame, which as in the former case
are supported at both ends by metal uprights secured to the side walls of the
outer wooden case. By these means practically the whole of the space behind the
sounding board is left free to receive the sounding chamber in the same manner as
described with regard to "iron frame" or "steel.frame" instruments.
"
"
"
The sounding board in this case will also be made so as to leave "sound holes
or "forte holes" on each side of the frame, and "sound holes"
or 'forte holes
with valves under the control either of a separate pedal or of the ordinary "forte
pedal" may also be formed, if desired, in the surrounding walls of the sounding
chamber.
It will be readily understood that the application of our Invention to existing
pianofortes will only necessitate the alteration of the parts of the instrument

page_text: "
"
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behind the sounding board, so as to permit of the introduction of the sounding
chamber in the desired position, the action of the instrument being in no way
affected by the same. The "sound holes or 'forte holes will in this case
preferably be only formed in the surrounding walls of the chamber, as it would
probably be inconvenient to form them in the sounding board itself.
"
The means for actuating the valves covering the "sound holes" or "forte holes
in the surrounding walls of the sounding chamber (if such holes be formed therein)
may be of any suitable description, whether the same be effected from a separate
pedal or by a suitable connection from the ordinary "forte pedal."