CERTAIN IMPROVEMENTS ON PIANOFORTES AND OTHER KETED MUSICAL INSTRUMENTS
Year: 1821

page_text: ERARD'S SPECIFICATION.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, PIERRE
EHARD, of Great Marlborough Street, in the County of Middlesex, Musical
Instrument Maker, send greeting.
WHEREAS His most Excellent Majesty King George the Fourth, did, by
5 His Letters Patent under the Great Seal of that part of the United Kingdom
of Great Britain and Ireland called England, bearing date at Westminster,
the Twenty-second day of December 1821, in the second year of His reign,
give and grant unto me, the said Pierre Erard, my exors, admňors, and assigns,
His especial licence, full power, sole privilege and authority, that I the said
Pierre Erard, my exors, admors, and assigns, during the term of years therein
mentioned, should and lawfully might make, use, exercise, and vend, within
England, Wales, and the Town of Berwick-upon-Tweed; the Invention,"
communicated to me by a certain foreigner residing abroad, of "CERTAIN
IMPROVEMENTS ON PIANOFORTES AND OTHER KETED MUSICAL INSTRUMENTS;
which said Letters Patent there is contained a proviso, that if I, the said Pierre
Erard shall not particularly describe and ascertain the nature of the said
Invention, and in what manner the same is to be performed, by an instrument
in writing under my hand and seal, and cause the same to be inrolled in
His Majesty's High Court of Chancery, within six calendar months next and
immediately after the date of the said Letters Patent, that then the said Letters
Patent and all liberties and advantages whatsoever, thereby granted, shall
utterly cease, determine, and become void, as in and: by the same (relation
being thereunto had,) will more fully and at large appear,,
in'

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NOW KNOW YE, that in compliance with the said proviso, I, the said
Pierre Erard, do hereby declare that the nature of the aforesaid improvements,
and the manner in which the same are to be produced and carried, into effect,
are herein-after particularly described and set-forth, (that is to say):-
:-
They consist in several points; among the most important of which is a
new and improved application of mechanism for that species of action known
under the denomination of, the escapement., Common pianofortes without an
escapement in their action, or where the sticker or riser. (this being the name
applied to that piece of wood, metal, or other material, which communicates
the motion of the key when pressed to the hammer that strikes the wire.) is
immoveable, possess the advantage of a great flexibility. in the touch; but on
the other hand they are defective on account of the liability of the hammer to
rebound or fly up to the string after, it has struck it, which presents its free
vibration, and is often destructive of its tone. In order to remedy, such defect
an escapement had been contrived and used in the sticker to let the hammer
fall away from the string after it has struck it; but the advantage.which such
escaping sticker or riser has over that which, is without escapement renders
the performer "subject to a very great inconvenience, namely, that of being
always obliged to raise up the finger so that the key may rise to the level of
the other keys before it will speak or repeat its note again, for without such
elevation of the key, the sticker cannot get again under the hammer to repeat
saction.
"
..
These difficulties are met and obviated by the present, Invention and
improvements, which require the combination of four points connected with
one action, namely, that of simply depressing the key.
The first is the application of a spring so contrived and adjusted that its
strength is made to support the weight of the hammer after it has made its
blow, and has escaped from its support upon the sticker or riser.
The's
e second is & contact which is brought about between the hammer, near
the centre upon which it moves, and the spring or lever; connected and
supported by such spring, in order to prepare the fall of the hammer when its
escapement takes place.
The third is a leve
و قید
third is a lever which by moving on its centre effects the escapement of
the ticker or riser from under the hammer.
The fourth is a piece so contrived with an 'adjusting screw as to catch the
hammer in its fall, and to stop or hold it as long as the key is kept entirely
down, so as to prevent the possibility of its rebounding to the wires again,
while it releases it again with the smallest rise of the finger end of the

page_text: These four contrivances, and the manner in which they may be conveniently
emcombined for the purpose a above stated, are explained in the following.description,
but which it is obvious may be varied in many particulars-without effecting
the
ne principles of the Invention.
WE M
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Fig. 1, Drawing No. 1, exhibits the above new mechanism for the piano-
forte as it stands when the key is up or at rest; and Fig. 2-represents the
same when the key is pressed quite down. These two Figures will shew the
effect produced, and are explaned as follows, the same letters of reference being
used to denote the same parts whenever they occur in these two-Figures:-
10 a, b, c, Fig. 1, is the key, its centre of action being at b, d, e, is the hammer,
with its centre of motion at d;fg, is an intermediate lever between the key
and the hammer, having its centre of motion in g; the motion of the key is
communicated to the intermediate lever f, g, by the piece hi, which turns on
its centre at i'and rests in a notch on the key at h: This motion is communi-
***15 cated from the intermediate lever to the hammer by the piece f, which may
be called the sticker or riser, by means of the metal or other staple m, fixed
under the tail of the hammer. But the hammer is: supported also by a spring
swhich is mounted on the auxiliary lever po, and keeps it apart from
the intermediate lever g, f; by pressing against the piece atig, seen more
20% distinctly at q; Figure 7. The opening of the spring and of its lever p, o, is
regulated by the wire hook: the lower end of which is a screw tapped into
the intermediate lever fig. The hammer tail, therefore, rests at the same time
on the sticker or riser f, k, and on the spring or auxiliary lever p, o, by means of
the staple m, as is clearly shewn by the section of such hammer, tail, auxiliary
25 lever, and staple, at Figure 3. The hammer is carried to the string by the
several parts as will be seen at Fig. 2, which shews the different. positions
which each of them takes. The key in this Figure has been entirely depressed
by the finger, and it clearly exhibits the advantages of this new mechanism;
the dotted line in red indicates that the hammer, as described that line to
330 strike the string; but whilst this operation is performing, the extremity p of the
auxiliary lever p. 0, Figure 1 and 2, comes into contact with the tail of
the hammer very near to its centre of motion at n (see Figure 2), and the
hammer d, e, having now more power to descend on account of the point
ast scofs bearing n, being nearer, its centre, such hammer by its own weight
35 forces the lever o, p, to go down, in opposition to its
9, s. In that
situation the spring q, r, has no, power or ef
effect on. the hammer which is
then supported upon a notch or step (1) by the sticker or riser f, k, alone, by
saises means of the staple m resting on such notch or step, see Figure. 2 and
the section Figure 4, until the projecting arm or tail f, y, of the sticker or riser

page_text: j.s
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which turns on its centre at f, comes into contact with the adjustable stop;
-&-by pressing upon which the notch or step of the sticker or riser f, k, is
i
made to escape froin under the staple m, (see Figure 2), at the same moment the
an idhammer falls the wedge-formed point of the adjustable piece u, (see
Figure 2) which prevents its flying up to the string again, and is there kept
secure as long" "as the key is kept entirely down. a", is a slight spring,
acting in any convenient form and manner upon the sticker or riser f, k, so as
to elevate the end y of its tail, and keep it in a proper position for engaging
with the staple m, the point of contact n, between the hammer and auxiliary
lever p, o, may be contrived and adjusted in several different ways, such as by
swell in the shape of the hammer, or in that of the lever p, o, or with one
or several thicknesses' of leather, or with a screw for better regulating the
pressure, as shewn at n Figure 1; 2, which latter method is preferable. The
wedge-formed piece u, which stops the hammer in its fall, is mounted with a
long screw for its "adjustment, as shewn in Figure 1, upon the branch or
arm v; a, which is immoveably fixed át v upon the intermediate lever f, g,
and by turning the piece u; with its "screw, more or less, the hammer may be
stopped with the greatest precision; a screw t, s, which presses on the
spring is, at one of its extremities, is indispensable to regulate its strength
or tightness for supporting the lever p, o, upon which all the weight of the
hammer rests, when by the escapement it no longer bears on the notch or
Step of the sticker, which, together with the lever, had put it in action.
It
is of the greatest importance in order to secure accuracy in the movements
bove described, that the main centre of 'action of the keys should be perfectly
oned as well fixed, so as to be firm and secure from shake. 1, 2, 3, Figure 5, indicate
the different, new, and improved ways of fixing such main centre by means
- centre pivot on the key, and No: 3 is preferable to the others as being
morêt simple; it consists of a metal screw or pin (9), fixed, screwed, or
driven as usual into the bottom of the key frame for the main centre of the
key to work upon; (10) is a square metal cap, which fixes upon the top
of the screw or pin (9), by the small screw (11), the square cap (10)
being let into the body of the key, as shewn at b. Figure 1 receives a
and thus forms a per-
"nee befectly steady hinge or pivot for it to move upon, while the key can at any
time be taken out by removing the screw (11). The other forms, 1 and 2,
will be sufficiently obvious from the above explanation: The piece of wire
lita, Figures I and 2; fixed at the extremity of the key, and which guides it
its action, is made of an oval shape instead of its' being round as usual,
gal which enables tone, by turning it partly round in the hole, to prevent its
email od ni huy
posta adiwire, which passes through the hole (12) in the cap,
into Gaz 29°/1

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shaking in its cavity after it has got loose by wear. 1, 2, 3, Figures 1 and 2,
represent new contrivances for a damper, which possess considerable advantages
over those now in use, namely, that of stopping the vibration of the wire short,
by means of the
pressure of a spring, besides the weight of the key 1, 2; and
51,3, are two little pieces or levers mounted and moving upon the same
centre 1, and kept apart from each other by a. spring 5, mounted upon
the same centre; they are maintained at their proper distance apart by a little
hook or wire pin 6, at the extremity of the upper lever. 1, 2, is attached by
a moving centre; the rod 2, 4, which carries the damper up to the string 3, 7,
10 is a long pin or wire screwed into or otherwise affixed, to the intermediate
lever f, g, as before mentioned, and moving with it, upon their common
centre g; this rod or wire of course partakes of the motion of the lever when
the key is depressed and the several pieces which compose, the damper come
down with it, and allow the string to vibrate freely, as is shewn at Figure 2.
15 To produce the forte with the pedal, or to take off the dampers from the
strings, an appropriate piece of wood or metal (8) is introduced, and this, by
the well-known ordinary contrivances of levers, pedals, or a pedal, comes down
upon the upper piece or lever 1, 2, which carries the damper 2, 4, and makes
it quit the string and allows it to vibrate freely; the little spring 5, admits of
20. this depression without disturbing (at all the other parts of the mechanism.
Figure 6 is an horizontal plan of the hammer d, e; the auxiliary lever p, o,
supported by the spring, q, r, s, such spring 9, s, and the holder of the
hammer u; these different pieces are drawn as they stand when the hammer
has struck the spring, and the finger is kept on the key; it exhibits also the
25 new and improved way of constructing the hammer by framing it of distinct
pieces of wood, and the manner in which it is attached to its centre d*, by
which means its position under the strings can be regulated with the greatest
accuracy; for this purpose the hinge or working centre of the hammer is
Prolonged into a piece formed as shewn sideways at e*, Figures 1 and 2, or as
30 shewn in plan at *, in Figure 6 and 7; these pieces are first fixed upon.the
rails f*, Figures 1 and 2, by single screws as at 9 in all, the said Figures
which done, a gentle tap, upon one or other side of the prolonged end h* of the
pieces will produce motion enough to adjust the opposite or striking end of
the hammer accurately under the wires, and as soon as this, is effected, a pin
35 or peg, sufficiently large to fill the little notch or saw cut h*, in the piece e*, is
driven into the rail f* through such notch, by which it becomes permanently
fixed in its proper place; and although a simple joint, consisting of a wire passing
through the several pieces, is used or represented in the Drawings as the
centre of motion, yet a pivot or centre, such as is represented at *, Figure 7,
"

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may occasionally be used, in which case the holes for the wire are first drilled
or formed, and afterwards sawed into or split, as particularly shewn in the side
view
Figure 7; a small screw or screws, as at *, are then inserted in a
transverse direction to such saw, cut, or slit, and by the tightning of which the
pivot hole can at any time be closed or diminished should, it wear large by
f. Figure 7, is a plan view of the intermediate lever, shewing its form
and construction, as well as the way, in which the different pieces appertaining
to it are connected with it. The centre of action 9,. of the intermediate
lever is constructed upon the same new methods as that of the hammer
already described, and the hinge or joint in both cases, is formed in like
manner and expressed by the same letters, as is the auxiliary lever in the
same, Figure, as also a front view, showing the manner of placing its
spring 9, s, before mentioned. Figures 8 and 9 represent two new ways
of holding the strings upon the bridge, which are used at one end instead of
the common bridge, near the rest pins; either of the contrivances may be used
for two, three, or more strings, but for the large strings, I prefer the small
pulleys, shewn at 1, Figures 1 and 9. It is of the greatest importance to
prevent the case and the sounding board of the instrument from being distorted
from their original forms by the tension of the strings, and the two following
Inventions are used, which answer all desirable purposes in that respect :-
A, A, A, Figure 1 of Drawing No. 11, shews the form of metal arches, which
are used as stays to connect the rest-pin block, and the hinder part or framing
of the instrument at the place, which is left for the hammers to come up to
the strings. Those arches in this Invention are
fixed on the rest-pin block
..
with screws
rews C, the heads of which rest on a plate D, sunk flush into the block;
they go entirely through the block, and are screwed under it in another
metal plate E, E, formed on one end of the arch; and instead of the other
end of the arch being fixed upon a bar which goes across the case of the
instrument in its width, as usual, they are mounted in the same way as upon
the rest-pin block, by screws, G, G, G, the heads of which rest upon a
plate H, H, formed in one piece with it, and screwed underneath into another
plate I, I, each arch being fixed upon a separate longitudinal bar or beam
F, F, which bears at its other end against the case of the instrument, and
und which arrangement I claim as part of this Invention. All those bars F, F,
rest upon the transverse bar K, (see Figure 1 and 3); from this bar K arise
between the bars F pieces of wood or blocks L, L, only seen in Figure 3, and
indicated by dots in Figure 1, which support the sounding board M, M, but
the blocks L, L, as well as the sounding board M, M, do not touch the
bars F, F, as is shewn at Figure 3. By this construction the different pieces

page_text: S
5.
are free from one another, which will prevent the rising and distortion of the
sounding board, which often happens in the common construction. Figure 2
is a plan of the metal arch A, with part of the rest-pin block and plate D, and
shewing also the plate H, H, and part of the longitudinal bar or beam F, F,
5 as already described. Figure 4 is a new sort of framing to be applied to the
curved part of the case of the pianoforte in the space between the bridge N
and the case O; it is composed of two pieces of wood p, p, glued or properly
fixed to each side of the sounding board M*, and likewise to the case O, with
the sounding board between them, which they allow to vibrate freely by their
10 angular shape; they are bound or connected together near the bridge N on
the sounding board by a hollow metal pillar Q, which is fixed by a screw p
passing through it into a nut q, which maintains the two pieces P, P, in their
proper position. Figures 5 and 6 of same Drawing, No. II., constitute
another part of the Invention, and represent an additional stop to be moved by
15 a pedal or other convenient means, for producing a new effect on
E
on the tone and
vibrations of the instrument; this is effected by a series of levers to be placed
at convenient distances from each other upon the sounding board in the space
"between the bridge N* placed upon it and the exterior case O"; those levers,
two of which are shewn at R, R, Figure 6 and 5, turn upon fixed centers
20 at r, r, while their opposite ends s, s, can press against the aforesaid bridge, or
may be turned away from their contact with it, as shewn by the dotted
"positions. They are so moved by a series of links or connecting rods T, T, T,
which communicate with the whole of them, and end in a lever formed as
at V, V; or in any other more convenient shape, which is acted upon by a
5 pedal. These levers are retained in the dotted positions, seen at Figure 6, by
springs or weights applied in any convenient part of the apparatus, and are
only brought into contact with the bridge when the pedal is pressed upon by
the performer, and their ends s, s, may be furnished with small wheels or rollers,
as shewn in the Drawing, to facilitate their
As the effect of these
30 levers depends upon their due pressure on the bridge N, they must be very
accurately fixed in the first instance, or else must be furnished with proper
screw or other adjustments for their lenght.
35
"
operation,
In witness whereof, I, the said Pierre Erard, have hereunto set my hand
and seal, this Twenty-second day of June, in the year of our Lord One
thousand eight hundred and twenty-two
DIEDDEL
מסים

page_text: AND BE IT REMEMBERED, that on the Twenty-second day of June,
in the year of our Lord 1822, the aforesaid Pierre Erard came before our
said Lord the King in His Chancery, and acknowledged the Specification
aforesaid, and all and every thing therein contained and specified, in form
above written. And also the Specification aforesaid was stamped according
to the tenor of the Statute made for that purpose.
Inrolled the Twenty-second day of June, in the year of our Lord One
thousand eight hundred and twenty-two.

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, PIERRE
ERARD, of Great Marlborough Street, in the County of Middlesex, Musical
Instrument Maker, send greeting.
WHEREAS His most Excellent Majesty King George the Fourth, did, by
His Letters Patent under the Great Seal of that part of the United Kingdom
of Great Britain and Ireland called England, bearing date at Westminster,
the Twenty-second day of December 1821, in the second year of His reign,
give and grant unto me, the said Pierre Erard, my exors, adiñors, and assigns,
His especial licence, full power, sole privilege and authority, that I, the said
Pierre Erard, my exors, adñiors, and assigns, during the term of therein
years
mentioned, should and lawfully might make, use, exercise, and vend, within
England, Wales, and the Town of Berwick-upon-Tweed, the Invention,
communicated to me by a certain foreigner residing abroad, of "CERTAIN
IMPROVEMENTS ON PIANOFORTES AND OTHER KEYED MUSICAL INSTRUMENTS;" in
which said Letters Patent there is contained a proviso, that if I, the said Pierre
Erard shall not particularly describe and ascertain the nature of the said
Invention, and in what manner the same is to be performed, by an instrument
in writing under my hand and seal, and cause the same to be inrolled in
His Majesty's High Court of Chancery, within six calendar months next and
immediately after the date of the said Letters Patent, that then the said Letters
Patent and all liberties and advantages whatsoever, thereby granted, shall
utterly cease, determine, and become void, as in and by the same, (relation
being thereunto had,) will more fully and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
Pierre Erard, do hereby declare that the nature of the aforesaid improvements,
and the manner in which the same are to be produced and carried into effect,
are herein-after particularly described and set-forth; (that is to say):-
They consist in several points; among the most important of which is a
new and improved application of mechanism for that species of action known
under the denomination of the escapement. Common pianofortes without an
escapement in their action, or where the sticker or riser (this being the name
applied to that piece of wood, metal, or other material, which communicates
the motion of the key when pressed to the hammer that strikes the wire.) is
immoveable, possess the advantage of a great flexibility in the touch; but on
the other hand they are defective on account of the liability of the hammer to
rebound or fly up to the string after it has struck it, which prevents its free
vibration, and is often destructive of its tone. In order to remedy such defect
an escapement had been contrived and used in the sticker to let the hammer
fall away from the string after it has struck it; but the advantage which such
escaping sticker or riser has over that which is without escapement renders
the performer subject to a very great inconvenience, namely, that of being
always obliged to raise up the finger so that the key may rise to the level of
the other keys before it will speak or repeat its note again, for without such.
elevation of the key, the sticker cannot get again under the hammer to repeat
its action.
These difficulties are met and obviated by the present Invention and
improvements, which require the combination of four points connected with
one action, namely, that of simply depressing the key.
The first is the application of a spring so contrived and adjusted that its
strength is made to support the weight of the hammer after it has made its
blow, and has escaped from its support upon the sticker or riser.
The second is a contact which is brought about between the hammer, near
the centre upon which it moves, and the spring or lever connected and
supported by such spring, in order to prepare the fall of the hammer when its
escapement takes place.
The third is a lever which by moving on its centre effects the escapement of
the sticker or riser from under the hammer.
The fourth is a piece so contrived with an adjusting screw as to catch the
hammer in its fall, and to stop or hold it as long as the key is kept entirely
down, so as to prevent the possibility of its rebounding to the wires again,
while it releases it again with the smallest rise of the finger end of the
key.

page_text: These four contrivances, and the manner in which they may be conveniently
combined for the purpose above stated, are explained in the following description,
but which it is obvious may be varied in many particulars without effecting
the principles of the Invention.
Fig. 1, Drawing, No. 1, exhibits the above new mechanism for the piano-
forte as it stands when the key is up or at rest; and Fig. 2 represents the
same when the key is pressed quite down. These two Figures will shew the
effect produced, and are explaned as follows, the same letters of reference being
used to denote the same parts whenever they occur in these two Figures:-
a, b, c, Fig. 1, is the key, its centre of action being at b; d, e, is the hammer,
with its centre of motion at d; f, g, is an intermediate lever between the key
and the hammer, having its centre of motion in g; the motion of the key is
communicated to the intermediate lever f, g, by the piece h, i, which turns on
its centre at i and rests in a notch on the key at h. This motion is communi-
cated from the intermediate lever to the hammer by the piece f, k, which may
be called the sticker or riser, by means of the metal or other staple m, fixed
under the tail of the hammer. But the hammer is supported also by a spring
q, r, s, which is mounted on the auxiliary lever p, o, and keeps it apart from
the intermediate lever g, f, by pressing against the piece at q, seen more
distinctly at 7, Figure 7. The opening of the spring and of its lever p, o, is
regulated by the wire hook., the lower end of which is a screw tapped into
the intermediate lever f, g. The hammer tail, therefore, rests at the same time
on the sticker or riser f, k, and on the spring or auxiliary lever p, o, by means of
the staple m, as is clearly shewn by the section of such hammer tail, auxiliary
lever, and staple, at Figure 3. The hammer is carried to the string by the
several parts as will be seen at Fig. 2, which shews the different. positions
which each of them takes. The key in this Figure has been entirely. depressed
by the finger, and it clearly exhibits the advantages of this new mechanism;
the dotted line in red indicates that the hammer as described that line to
strike the string; but whilst this operation is performing, the extremity p of the
auxiliary lever p, o, Figure 1 and 2, comes into contact with the tail of
the hammer very near to its centre of motion at n' (see Figure 2), and the
hammer d, e, having now more power to descend on account of the point
of bearing n, being nearer its centre, such hammer by its own weight
forces the lever o, p, to go down, in opposition to its spring q, ?, s. In that
situation the spring q, r; s, has no power or effect on the hammer which is
then supported upon a notch or step (1) by the sticker or riser f, k, alone, by
means of the staple m resting on such notch or step, see Figure. 2 and
the section Figure 4, until the projecting arm or tail f, y, of the sticker or riser

page_text: which turns on its centre at f, comes into contact with the adjustable stop;
& by pressing upon which the notch or step of the sticker or riser f, k, is
made to escape from under the staple m, (see Figure 2), at the same moment the
hammer falls past the wedge-formed point of the adjustable piece u, (sec
Figure 2) which prevents its flying up to the string again, and is there kept
secure as long as the key is kept entirely down. a, is a slight spring,
acting in any convenient form and manner upon the sticker or riser f, k, so as
to elevate the end y of its tail, and keep it in a proper position for engaging
with the staple m, the point of contact n, between the hammer and auxiliary
lever p, o, may be contrived and adjusted in several different ways, such as by
a swell in the shape of the hammer, or in that of the lever p, o, or with one
or several thicknesses of leather, or with a screw for better regulating the
pressure, as shown at n, Figure 1, 2, which latter method is preferable. The
wedge-formed piece u, which stops the hammer in its fall, is mounted with a
long screw for its adjustment, as shewn in Figure 1, upon the branch or
arm v, a, which is immoveably fixed at v upon the intermediate lever f, g,
and by turning the piece u, with its screw, more or less, the hammer may be
stopped with the greatest precision; a screw t, s, which presses on the
spring q, r, s, at one of its extremities, is indispensable to regulate its strength
or tightness for supporting the lever p, o, upon which all the weight of the
hammer rests, when by the escapement it no longer bears on the notch or
It
step of the sticker, which, together with the lever, had put it in action.
is of the greatest importance in order to secure accuracy in the movements
above described, that the main centre of action of the keys should be perfectly
ivell fixed, so as to be firm and secure from shake. 1, 2, 3, Figure 5, indicate
the different, new, and improved ways of fixing such main centre by means
of a centre pivot on the key, and No. 3 is preferable to the others as being
more simple; it consists of a metal screw or pin (9), fixed, screwed, or
driven as usual into the bottom of the key frame for the main centre of the
key to work upon; (10) is a square metal cap, which fixes upon the top
of the screw or pin (9), by the small screw (11), the square cap (10)
being let into the body of the key, as shewn at b. Figure 1 receives a
and thus forms a per-
wire, which passes through the hole (12) in the cap,
fectly steady hinge or pivot for it to move upon, while the key can at any
time be taken out by removing the screw (11). The other forms, 1 and 2,
will be sufficiently obvious from the above explanation. The piece of wire
at a, Figures 1 and 2, fixed at the extremity of the key, and which guides it
in its action, is made of an oval shape instead of its being round as usual,
which enables one, by turning it partly round in the hole, to prevent its

page_text: shaking in its cavity after it has got loose by wear. 1, 2, 3, Figures 1 and 2,
represent new contrivances for a damper, which possess considerable advantages
over those now in use, namely, that of stopping the vibration of the wire short,
by means of the pressure of a spring, besides the weight of the key 1, 2; and
1, 3, are two little pieces or levers mounted and moving upon the same
centre 1, and kept apart from each other by a spring 5, mounted upon
the same centre; they are maintained at their proper distance apart by a little
hook or wire pin 6, at the extremity of the upper lever. 1, 2, is attached by
a moving centre; the rod 2, 4, which carries the damper up to the string 3, 7,
is a long pin or wire screwed into or otherwise affixed to the intermediate
lever f, g, as before mentioned, and moving with it upon their common
centre g; this rod or wire of course partakes of the motion of the lever when
the key is depressed and the several pieces which compose the damper come
down with it, and allow the string to vibrate freely, as is shewn at Figure 2.
To produce the forte with the pedal, or to take off the dampers from the
strings, an appropriate piece of wood or metal (8) is introduced, and this, by
the well-known ordinary contrivances of levers, pedals, or a pedal, comes down
upon the upper piece or leyer 1, 2, which carries the damper 2, 4, and makes
it quit the string and allows it to vibrate freely; the little spring 5, admits of
this depression without disturbing [at all the other parts of the mechanism.
Figure 6 is an horizontal plan of the hammer d, e; the auxiliary lever p, o,
supported by the spring 2, 1, s, such spring q, r, s, and the holder of the
hammer u; these different pieces are drawn as they stand when the hammer
has struck the spring, and the finger is kept on the key; it exhibits also the
new and improved way of constructing the hammer by framing it of distinct
pieces of wood, and the manner in which it is attached to its centre d*, by,
which means its position under the strings can be regulated with the greatest
accuracy; for this purpose the hinge or working centre of the hammer is
prolonged into a piece formed as shewn sideways at e*, Figures 1 and 2, or as
shown in plan at e, in Figure 6 and 7; these pieces are first fixed upon the
rails f, Figures 1 and 2, by single screws as at g; in all the said Figures
which done, a gentle tap upon one or other side of the prolonged end h* of the
pieces will produce motion enough to adjust the opposite or striking end of
the hammer accurately under the wires, and as soon as this is effected, a pin
or peg, sufliciently large to fill the little notch or saw cut *, in the piece e*, is
driven into the rail f* through such notch, by which it becomes permanently
fixed in its proper place; and although a simple joint, consisting of a wire passing
through the several pieces, is used or represented in the Drawings as the
centre of motion, yet a pivot or centre, such as is represented at 2. Figure 7,

page_text: may occasionally be used, in which case the holes for the wire are first drilled
or formed, and afterwards sawed into or split, as particularly shewn in the side
view Figure 7; a small screw or screws, as at *, are then inserted in a
transverse direction to such saw, cut, or slit, and by the tightning of which the
pivot hole can at any time be closed or diminished should it wear large by
use. 9, f, Figure 7, is a plan view of the intermediate lever, shewing its form
and construction, as well as the way in which the different pieces appertaining
to it are connected with it. The centre of action g, of the intermediate
lever g, f, is constructed upon the same new methods as that of the hammer
already described, and the hinge or joint in both cases is formed in like
manner and expressed by the same letters, as is the auxiliary lever in the
same Figure, as also a front view, showing the manner of placing its
spring q, r, s, before. mentioned. Figures 8 and 9 represent two new ways
of holding the strings upon the bridge, which are used at one end instead of
the common bridge near the rest pins; either of the contrivances may be used
for two, three, or more strings, but for the large strings, I prefer the small
pulleys, shewn at *, Figures 1 and 9. It is of the greatest importance to
prevent the case and the sounding board of the instrument from being distorted
from their original forms by the tension of the strings, and the two following
Inventions are used, which answer all desirable purposes in that respect:-
A, A, A, Figure 1 of Drawing No. 11, shews the form of metal arches, which
are used as stays to connect the rest-pin block, and the hinder part or framing
of the instrument at the place which is left for the hammers to come up to
the strings. Those arches in this Invention are fixed on the rest-pin block
with screws C, the heads of which rest on a plate D, sunk flush into the block;
they go entirely through the block, and are screwed under it in another
metal plate E, E, formed on one end of the arch; and instead of the other
end of the arch being fixed upon a bar which goes across the case of the
instrument in its width, as usual, they are mounted in the same way as upon
the rest-pin block, by screws G, G, G, the heads of which rest upon a
plate H, H, formed in one piece with it, and screwed underneath into another
plate I, I, each arch being fixed upon a separate longitudinal bar or beam
F, F, which bears at its other end against the case of the instrument, and
which arrangement I claim as part of this Invention. All those bars F, F,
rest upon the transverse bar K, (see Figure 1 and 3); from this bar K arise
between the bars F pieces of wood or blocks L, L, only seen in Figure 3, and
indicated by dots in Figure 1, which support the sounding board M, M, but
the blocks L, L, as well as the sounding board M, M, do not touch the
bars F, F, as is shown at Figure 3. By this construction the different pieces

page_text: are free from one another, which will prevent the rising and distortion of the
sounding board, which often happens in the common construction. Figure 2
is a plan of the metal arch A, with part of the rest-pin block and plate D, and
shewing also the plate H, H, and part of the longitudinal bar or beam F, F,
as already described. Figure 4 is a new sort of framing to be applied to the
curved part of the case of the pianoforte in the space between the bridge N
and the case 0; it is composed of two pieces of wood p, p, glued or properly
fixed to each side of the sounding board M, and likewise to the case O, with
the sounding board between them, which they allow to vibrate freely by their
angular shape; they are bound or connected together near the bridge N on
the sounding board by a hollow metal pillar Q, which is fixed by a screw p
passing through it into a nut q, which maintains the two pieces P, P, in their
proper position. Figures 5 and 6 of same Drawing, No. II., constitute
another part of the Invention, and represent an additional stop to be moved by
a pedal or other convenient means, for producing, a new effect on the tone and
vibrations of the instrument; this is effected by a series of levers to be placed
at convenient distances from each other upon the sounding board in the space
between the bridge N* placed upon it and the exterior case O*; those levers,
two of which are shewn at R, R, Figure 6 and 5, turn upon fixed centers
at r, r, while their opposite ends s, s, can press against the aforesaid bridge, or
may be turned away from their contact with it, as shewn by the dotted
positions. They are so moved by a series of links or connecting rods T, T, T,
which communicate with the whole of them, and end in a lever formed as
at V, V, or in any other more convenient shape, which is acted upon by a
pedal. These levers are retained in the dotted positions, seen at Figure 6, by
springs or weights applied in any convenient part of the apparatus, and are
only brought into contact with the bridge when the pedal is pressed upon by
the performer, and their ends s, s, may be furnished with small wheels or rollers,
as shewn in the Drawing, to facilitate their operation, As the effect of these
levers depends upon their due pressure on the bridge N*, they must be very
accurately fixed in the first instance, or else must be furnished with proper
screw or other adjustments for their lenght.
In witness whereof, I, the said Pierre Erard, have hereunto set my hand
and seal, this Twenty-second day of June, in the year of our Lord One
thousand eight hundred and twenty-two.
PIERRE (L.s.) ERARD.

page_text: AND BE IT REMEMBERED, that on the Twenty-second day of June,
in the year of our Lord 1822, the aforesaid Pierre Erard came before our
said Lord the King in His Chancery, and acknowledged the Specification
aforesaid, and all and every thing therein contained and specified, in form
above written. And also the Specification aforesaid was stamped according
to the tenor of the Statute made for that purpose.
T 11 1 entre cond don of Tuna in the roar of our Low! Ona
Imrolled the Twenty second day of June, in the
thousand eight hundred and twenty-two.
our Low One
of our