IMPROVEMENTS IN PIANOFORTES
Year: 1862

page_text: LETTERS PATENT to Charles Louis Knoll, of 187, Tottenham Court Road,
in the County of Middlesex, for the Invention of "IMPROVEMENTS IN
PIANOFORTES."
Sealed the 22nd August 1862, and dated the 26th February 1862.
PROVISIONAL SPECIFICATION left by the said Charles Louis Knoll at
the Office of the Commissioners of Patents, with his Petition, on the
26th February 1862.
I, CHARLES LOUIS KNOLL, of 187, Tottenham Court Road, in the County of
Middlesex, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN PIANOFORTES," to be as follows:-
This Invention consists, firstly, of certain improvements in the construction
and arrangement of the mechanism of oblique and cottage pianofortes, whereby
the action of the hammers upon the strings, which at present is from the front
of the instrument in a backward direction, is reversed, and the hammers are
caused to strike from the back of the instrument against the strings or scale,
and whereby the body of the instrument may be extended in width beyond
that of the key-board, so as to allow of operation upon a greater range or
extent of scale than is obtained by the instruments now in use.
In order to effect these results the connecting rods from the keys are made
to pass downwards in the front of the interior of the instrument, at the lower

page_text: part of which they actuate a corresponding number or series of horizontal
levers, which extend to the back of the instrument, where they are again con-
nected to vertical connecting rods which ascend behind the scale or strings,
and are joined to the mechanism of the hammers, which in consequence are
caused to strike the strings behind instead of in front, thereby increasing the
effect of the instrument, and rendering the tone considerably more powerful
than that produced by the present action of the hammers, the sound being
thrown forwards into the room instead, of backwards towards a recess or wall,
against which the instrument is ordinarily placed. In order to increase the
length of the strings or scale the body of the instrument is to be extended in
width beyond that of the key-board, and the scale is arranged obliquely; it
is then necessary to change the directions of the horizontal levers, and to cause
them to diverge from their common parallel positions to an oblique direction
with regard to the keys, in order that they may reach and actuate the more
extended width of the back vertical rods and hammers, which operate on the
oblique and extended scale of strings. By these means all the keys. may
remain parallel to each other, and the key-board may be of the ordinary and
regular width according to the compass of the instrument. And at the same
time the body of the instrument and scale, which it contains, may be con-
siderably extended and its power proportionably increased. These improve-
ments may also be applied to those pianos in which the base scale is oblique
and the treble vertical.
The Invention consists, secondly, of improvements in the rest plank, which
is ordinarily composed of wood, but which it is proposed to form of wood,
iron bars, or plates and brass, so as to constitute a compound rest plank,
which is to be formed of wood with a plate or bar of iron at the upper
and lower surface, thereof, the whole being covered or encased with sheet or
cast brass. The iron plates or bars, about six of which would generally
be sufficient, acting as strengthening bars for the rest plank and metallic
plate. Female screws are to be drilled through this rest plank for the rest
pins to enter, on which the strings are fastened, and whereby the instrument
is tuned. The advantages of this arrangement are that the hitherto
injurious effects of atmospheric influence upon the wooden rest plank are
avoided, the wood being preserved by the metal from the effects of hot
climates or dampness, and also that the rest pins. on which the strings are
attached passing through the brass plate in front.and behind the rest plank are
beld firmly in position, and the pins and plank prevented from getting out of
order, or from being tampered with; since the pins must always be turned by

page_text: the tuning key and connot be driven in by a blow. The tone and tune of 'the
instrument will thus be preserved for a much longer period than can be
obtained by the present wooden rest planks.
The Juvention consists, thirdly, of an improvement in the balance key pins,
which are at present made in a circular form at their upper ends where. the
slots or grooves in the keys are worked; but, it is now proposed to make the
upper ends of these key pins of an oval shape in their horizontal section, and
to fix them on the key frame in such a position that their transverse diameter
shall be parallel with the lines of the slots and keys, the slots being mado
narrow, so that the keys may rock thereon evenly and regularly, and without
lateral oscillation, the object being that as the slots become worn and enlarged
by use these oval balance key pins may be slightly and gradually turned from
their original position, and the transverse diameter eventually brought to bear
upon the enlarged or worn slot. Thus these oval pins will serve to maintain
for many years the even working of the keys, notwithstanding the wear of
their slots, a desideratum which cannot be accomplished by the present
circular balance pin. The instruments are tuned from the front as at present.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Charles Louis Knoll in the Great Seal Patent Office
on the 26th August 1862.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, СHARLES
LOUIS KNOLL, of 187, Tottenham Court Road, in the County of Middlesex,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-sixth day of February, in the year of our.
Lord One thousand eight hundred and sixty-two, in the twenty-fifth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Charles Louis Knoll, Her special licence that I, the said Charles
Louis Knoll, my executors, administrators, and assigns, or such others
as I, the said Charles Louis Knoll, executors, administrators, and
assigns, should at any time agree with, and no others, from time to
time and at all times thereafter during the term therein expressed, should.
and lawfully might make, use, exercise, and vend, within the United King-
dom of Great Britain and Ireland, the Channel Islands, and Isle of Man, an
Invention for "IMPROVEMENTS IN PIANOFORTES," upon the condition (amongst

page_text: others) that I, the said Charles Louis Knoll, my executors or administrators,
by an instrument in writing under my, or their, or one of their hands and
seals, should particularly describe and ascertain the nature of the said Inven-
tion, and in what manner the same was to be performed, and cause the
same to be filed in the Great Seal Patent Office within six calendar months
next and immediately after the date of the said Letters Patent.
• NOW KNOW YE, that I, the said Charles Louis Knoll, do hereby
declare the nature of my said 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 consists, firstly, of certain improvements in the construction
and arrangement of the mechanism of oblique and cottage pianofortes, whereby
the action of the hammers upon the strings, which at present is from the front
of the instrument in a backward direction, is reversed, and the hammers are
caused to strike from the back of the instrument against the strings or scale;
and whereby the body of the instrument may be extended in width beyond
that of the key-board, so as to allow of operation upon a greater range or
extent of scale than is obtained by the instruments now in use.
In order to effect these results, the connecting rods from the keys are to be
made to pass downwards in the front of the interior of the instrument, at the
lower part of which they actuate a corresponding number or series of hori-
zontal levers which extend to the back of the instrument, where they are
again connected to vertical connecting rods, which ascend behind the scale or
strings, and are joined to the mechanism of the hammers, which in conse-
quence are caused to strike the strings behind instead of in front, thereby
increasing the effect of the instrument, and rendering the tone considerably
more powerful than that produced by the present action of the hammers, the
sound being thrown forwards into the room instead of backwards towards a
recess or wall, against which the instrument is ordinarily placed. In order to
increase the length of the strings or scale, the body of the instrument is to be
extended in width beyond that of the key-board, and the scale is arranged
obliquely; it is then necessary to change the directions of the horizontal levers,
and to cause them to diverge from their common parallel positions to an
oblique direction with regard to the keys, in order that they may reach and
actuate the more extended width of the back vertical rods and hammers, which
operate on the oblique and extended scale of strings. By these means all the
keys may remain parallel to each other, and the key-board may be of the
ordinary and regular width, according to the compass of the instrument, and

page_text: at the same time the body of the instrument and scale which it contains may
be considerably extended and its power proportionably increased. Theso
improvements may also be applied to those pianos, in which the base scale is
oblique and the treble vertical.
The Invention consists, secondly, of improvements in the rest plank, which
is ordinarily composed of wood, but which it is proposed to form of wood,
iron bars, or plates, and brass, so as to constitute a compound rest plank, which
is to be formed of wood with a plate or bar of iron at the upper and lower
surface thereof, the whole being covered or encased with sheet or cast brass;
the iron plates or bars, about six of which would generally be sufficient,
acting as strengthening bars for the rest plank and metallic plate. Female
screws are to be drilled through this rest plank for the rest pins to enter, on
which the strings are to be fastened, and whereby the instrument is tuned.
The advantages of this arrangement are are that the hitherto injurious effects
of atmospheric influence upon the wooden rest plank are avoided, the wood
being preserved by the metal from the effects of hot climates or dampness;
and also that the rest pins on which the strings are attached, passing through
the brass plate in front and behind the rest plank, are held firmly in position,
and the pins and plank prevented from getting out of order or from being
tampered with, since the pins must always be turned by the tuning key, and
cannot be driven in by a blow. The tone and tune of the instrument will thus
be preserved for a much longer period than can be obtained by the present
wooden rest planks.
My Invention consists, thirdly, of an improvement in the balance key pins,
which are at present made in a circular form at their upper ends where the
slots or grooves in the keys are worked; but it is now intended by this Inven-
tion to make the upper ends of these key pins of an oval shape in their horizontal
section, and to fix them on the key frame in such a position that their trans-
verse diameter shall be parallel with the lines of the slots and keys, the slots
being made narrow, so that the keys may rock thereon evenly and regularly,
and without lateral oscillation; the object being that as the slots become worn
and enlarged by use these oval balance key pins may be slightly and gradually
turned from their original position, and the transverse diameter eventually
brought to bear upon the enlarged or worn slot. Thus these oval pins will
serve to maintain for many years the even working of the keys, notwith-
standing the wear of their slots, a desideratum which cannot be accomplished
by the present circular balance pin. The instruments are to be tuned from
the front as at present.

page_text: Having now described the nature of my said Invention, and the manner
in which the same is to be performed, I would remark in conclusion that
.I do not limit or restrict myself to the precise details herein described, as
the same may be varied or modified without departing from the principles of
the Invention; but what I claim and desire to be secured to me by the herein
in part recited Letters Patent are, the several improvements in pianofortes,
substantially as herein specified.
In witness whereof, I, the said Charles Louis Knoll, have hereunto set
my hand and seal, this Twenty-sixth day of August, in the year of
our Lord One thousand eight hundred and sixty-two.
CHARLES LOUIS KNOLL. (L.S.)
Witness,
L. J. WETHERELL,
Clerk to Messrs. Prince, Hammond, & Prince,
Patent Agents,
4, Trafalgar Square,
Charing Cross..