IMPROVEMENTS IN PIANOFORTES
Year: 1884

page_text: I GEORGE KEMP of Pilton near Barnstaple in the county of Devon Doctor of
Medicine do hereby declare the nature of my said Invention for IMPROVEMENTS
IN PIANOFORTES to be as follows:-
To produce a softer tone in pianofortes without using a shifting key board what
is commonly known as a "celeste "action has been used by the which a strip of
cloth is interposed between the hammers and the wires at the desired time. The
objection to this action is that there is no real diminuendo or crescendo in the tone
thereby produced which is abruptly changed froin the loud to the soft tone.
immediately this strip of cloth is so interposed as aforesaid. Now the object of
this my invention is to obviate this evil and fit a polyphonic apparatus to piano-
fortes by means of which any desired loudness or softness of tone may be produced
at the will of the executant.
I carry out this object by using a band on which I support a series of pieces of..
a soft material which are interposed between the haminers and the wires when a
softer tone is desired. These pieces of soft material are so arranged and formed
that there are different steps or thicknesses therein which the band can so interpose
and thus when a very slight decrease in the intensity of the sound is desired the
first step or thinnest thickness only is interposed and then when a further decrease
is desired the second step or the next thickness is used and so on. The material
so used as aforesaid may be cloth or felt or other similar and suitable material.
I consider also that cords inade of the ordinary worsted that is used for knitting.
and similar purposes are very suitable a cord of one strand being used for the first
step or thinnest thickness a cord of two strands for the next and so on: One end
of the band which so supports the soft material is fixed on the frame of the piano-
forte in the proper position on one side and the other end is actuated by a pedal
through suitable levers and cranks or similar apparatus on the other side to draw
the said band forwards or backwards and bring it into the required position for
the operation of the haminers from which position the said band can be retired
when the pedal is released by any suitable spring. I can also fit an eccentric to act
on the fixed end of the band which also would be operated by the same pedal for
the same purpose. A suitable tension must be given to the band and the material
supported thereby across the pianoforte in any suitable manner a convenient
method being the insertion of a piece of india rubber or other elastic material
between the end of the band or of the material supported thereby and the frame of
the pianoforte or the part of the actuating apparatus to which it is secured..

page_text: I GEORGE KEMP of Pilton near Barnstaple in the county of Devon Doctor of
Medicine do hereby declare the nature of iny said invention for IMPROVEMENTS
IN PIANOFORTES and in what manner the same is to be performed, to be particu-
larly described and ascertained in and by the following statement :-
When it is desired to produce a softer tone in pianofortes without using a
shifting key board what is commonly known as a "celesto" action has been used
by the which a strip of cloth or other material is interposed between the hammers
and the wires at the required and necessary time. The objection to this apparatus
is that there is no real diminuendo or crescendo in the tone thereby produced,
which on the contrary is abruptly changed from the loud to the soft tone imme-
diately the strip is so interposed as aforesaid. Now the object of this my
invention is to obviate this evil and fit a polyphonic apparatus to pianofortes by
means of which any desired loudness and softness of tone may be produced at the
. will of the executant.
I carry out this object by using a band or frame or lath on or in or by which
I support a series of pieces or strips of a soft material which are or. can be inter-.
posed between the hammers and the wires when a softer tone is desired. These
aforesaid pieces or strips of a soft material are so arranged and formed that there
are different steps or thicknesses therein which the band or frame or lath can so
interpose as aforesaid and thus when a very slight decrease in the intensity of the
sound is desired the first step or the thinnest thickness of the said soft material
only is interposed as aforesaid and then when a further decrease in the intensity of
the sound is desired the second step or the next thickness of the said soft material
is interposed as aforesaid and so on. The soft material so used as aforesaid may
be cloth or felt or other similar and suitable material. I consider also that cords
made of the ordinary worsted that is used for knitting and similar purposes and
other like material are very suitable for use in this my invention as herein before
.described a cord of one strand being used for the first step or thinnest thickness
aforesaid a cord of two strands for the next and so on. One end of the band or
frame or lath which so supports as aforesaid the soft material is fixed or pivotted
on or otherwise attached to the frame of the pianoforte or the check of the case
thereof or elsewhere in the proper position on one side most preferably the treble
side and the other end is actuated as may be most convenient by any suitablo
apparatus or appliance to draw or move the said band or frame or lath forwards or,
back wards and bring the same into the required position for the operation of the
hammers on one of the herein before described steps or thicknesses of the soft
inaterial supported thereon or therein or thereby as is desired. When it is desired
permanently or during the whole time of playing on the instrument to reduce the
volume of sound an ordinary draw stop or other similar appliance can very
-conveniently be fitted to the free end of the band or frame or lath to actuate the
same as is hereinbefore described by hand and when required to put this apparatus
out of action. When on the other hand it is desired to vary the intensity of the
sound during the period of playing on the instrument and thus produce the
i

page_text: diminuendo and crescendo effects required the free end of the band or frame or
lath is preferably connected with a pedal through any suitable levers and cranks
or similar apparatus whereby the depression of the said pedal will draw or move
the said band or frame or lath forwards or backwards for the purpose herein before
described and thus vary to the desired extent the intensity of the sound and a
spring or other appliance can be fitted to retire the said band or frame or lath
from this position when the said pedal is released. I can also fit an eccentric to
act on the fixed end of the band especially if and when the said band is so fixed or
pivotted or attached on the bass side which eccentric would likewise be operated ·
by the pedal, for the same purpose as hereinbefore described but for general and
common use and particularly if and when the said band or the frame or lath is
fixed or pivotted or attached as is preferable on the treble side I do not consider
this arrangement to be necessary for in and by my aforesaid method of fixing or
pivotting or attaching this the treble end of the band or frame or lath as herein-
before described quite à sufficient thickness for all practical purposes of the soft
material will in all cases be interposed when the said band or frame or lath is
moved as aforesaid between the hammers and the extreme treble wires and as
generally the space between the wrest plank and the belly of the instrument
gradually widens from the treble end to the bass end it is then obligatory that the
motion of the said band or frame or lath shall correspond to this aforesaid increase
of width by being greater at the said bass end than at the said treble end and thus
no practical inconvenience will be experienced from allowing the said treble end to
move only as on a centre or pivot as is herein before described. A proper tension
inust be given to the band and to the material supported thereon or to the material
supported in or by the frame or lath across the pianoforte in any suitable manner
a convenient method being the insertion of a piece of india rubber or other elastic
material between the end of the said band or of the said material and the frame of
the pianoforte or the cheek of the case thereof or the end of the said frame or lath
or that part of the actuating apparatus to which the free end of the said band or
of the said frame or lath is attached.
I have thus described this my invention as applied generally to all kinds of
pianofortes and now in the accompanying drawing I have shewn, one form of this
my apparatus as applied to a grand pianoforte according to one of my methods as
hereinbefore described.
Figure 1 is a plan of part of a pianoforte fitted with my apparatus the action of
which pianoforte is removed for purposes of clearness. Figure 2 is a vertical
section of the same. Figure 3 is a plan of part of my polyphonic apparatus herein.
before described on an enlarged scale. Figure 4 is a cross section of the same on
a still larger scale.
According to this form and method one end of the frame A is pivotted on the
treble side on the cheek of the case of the pianoforte at B while the other end of
the said frame A is connected with the pedal C through the levers and cranks D so
that the depression of the said pedal C will draw the said frame A forwards as and
when is desired. In this frame A are secured a series of pieces or strips of cloth
or other soft ñaterial E which are superposed the one on the other in such a
manner that different steps or thicknesses are formed as shewn in Figure 4. The
frame A is located in such a position near the space between the wrest plank F
and the belly G of the instrument that when the said frame A is in the retired.
position as shewn in the drawing the hammers can directly strike the strings.but
when the said frame A is drawn forwards by the depression of the pedal C one
of these different steps or thicknesses of the soft material E are interposed between
the hammers below and the strings above and the amount of such depression of
the pedal C regulates and settles which of the said different steps or thicknesses of
the soft material E shall be so interposed as aforesaid and thus the decrease or
increase of the intensity of the sound is regulated and varied as is desired.
as is bereinbefore stated a draw stop or other similar appliance is used instead
of a pedal to move the apparatus hereinbefore described forwards and backwards
When
•

page_text: the said draw stop or other appliance can be connected with the end of the frame
either directly or through any suitable lever or levers.
The frame A can also obviously be so arranged and formed and the actuating
apparatus can be so fitted as to allow the said frame A to be moved backwards or
away from the key board of the instrument to interpose as aforesaid the soft
.material between the hammers and the strings when this arrangement and method
of action is for any cause preferred.
When a lath is used instead of the frame shewn in the-drawing the apparatus is
'fitted in the same manner as hereinbefore described.
When a band is used to support the pieces or strips of soft material instead of
the frame shewn in the drawing and the action or motion thereof required to bring
the apparatus into position for use is forwards or towards the key board of the
instrument also as shewn in the drawing I'preferably fit on the wrest plank F
.a suitable number of small.projections H by the which the said band or the soft
material thereon is supported when the said band is drawn completely forwards to
bring the thickest part of the said soft material into action and thus I maintain
the same at the desired distance from and parallel or thereabouts with the plane of
the strings.
This my apparatus can also obviously be fitted and applied, in a similar manner
to all other descriptions and. kinds of pianofortes to vary the intensity, of the sound
and no further description is or can be needed.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is
'
In pianofortes the apparatus consisting of a band or frame or lath supporting
soft material of different thicknesses whereby the intensity of the sound produced
may be varied substantially as herein before described and set forth.
Dated this 18th day of June 1885.