IMPROVEMENTS IN THE CONSTRUCTION OF THE ACTION OF PIANOFORTES
Year: 1858

page_text: LETTERS PATENT to James Stewart, of 69, Tottenham Court Road, in
the County of Middlesex, for the Invention of "IMPROVEMENTS IN THE
CONSTRUCTION OF THE ACTION OF PIANOFORTES."
Sealed the 7th June 1859, and dated the 9th December 1858.
PROVISIONAL SPECIFICATION left by the said James Stewart at the
Office of the Commissioners of Patents, with his Petition, on the 9th
December 1858.
I, JAMES STEWART, of 69, Tottenham Court Road, in the County of
Middlesex, do hereby declare the nature of the Invention for "IMPROVEMENTS
IN THE CONSTRUCTION OF THE ACTION OF PIANOFORTES," to be as follows:-
This Invention has for its object improvements in the construction of thic
action of pianofortes. The fly or hopper of the pianoforte action is usually
furnished with a spring, which holds it in position to act on the part to which
it gives motion, the spring yielding to allow the fly or hopper to escape when
it has moved through a sufficient distance to bring its end on to an incline
formed on the part on which it acts. The position of the end of the fly or
hopper at the beginning of its motion is regulated by a stop called an escape-
ment button, which is adjustable by means of a screw; the escapement button
has in some cases been mounted on the fly or hopper, and it then abuts upon
a projection fixed to the piece carrying the fly or hopper, and in some cases the
button has been mounted on this projection, and the hopper has rested directly

page_text: upon it.
When the former construction has been adopted, the button has
heretofore been so arranged, that when the fly or hopper is forced up against
it by the spring, the button is not when it comes against the projection moving
in a direction perpendicular to the surface of the projection, but in a direction
inclined thereto, and from this cause the fly or hopper in escaping takes
longer to get free, that is to say, the fly or hopper has to move farther before
the soft surface of the button is lifted off the soft surface of the projection.
Now, according to my Invention, the escapement button is mounted on the
fly or hopper at such an inclination that just as it comes against the surface
of the projection it is moving in a direction perpendicular to that surface.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said James Stewart in the Great Seal Patent Office on the 9th
.June 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
STEWART, of 69, Tottenham Court Road, in the County of Middlesex, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Ninth day of December, in the year of our Lord
One thousand eight hundred and fifty-eight, in the twenty-second year of
Her reign, did, for Herself, Her heirs and successors, give and grant
unto me, the said James Stewart, IIer special licence that I, the said James
Stewart, my executors, administrators, and assigns, or such others as I,
the said James Stewart, my 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 Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for "IMPROVE-
MENTS IN THE CONSTRUCTION OF THE ACTION OF PIANOFORTES," upon the condition
(amongst others) that I, the said James Stewart, my executors or adminis-
trators, 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 Invention, 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 James Stewart, do hereby declare the
nature of the said Invention, and in what manner the same is to be per-

page_text: formed, to be particularly described and ascertained in and by the following
statement thereof, that is to say:-
This Invention has for its object improvements in the construction of the
action of pianofortes. The fly or hopper of the pianoforte action is usually
furnished with a spring which bolds it in position to act on the part to which
it gives motion, the spring yielding to allow the fly or hopper to escape when
it has moved through a sufficient distance to bring its end on to an incline
formed on the part on which it acts. The position of the end of the fly or
hopper at the beginning of its motion is regulated by a stop called an escape-
ment button, which is adjustable by means of a screw; the escapement button
has in some cases been mounted on the fly or hopper, and it then abuts upon
a projection fixed to the piece carrying the fly or hopper, and in some cases
the button has been mounted on this projection, and the hopper has rested
directly upon it. When the former construction has been adopted the button
has heretofore been so arranged that when the fly or hopper is forced up
against it by the spring, the button is not, when it comes against the projection,
moving in a direction perpendicular to the surface of the projection, but in a
direction inclined thereto, and from this cause the fly or liopper in escaping
takes longer to get free, that is to say, the fly or hopper has to move further
before the soft surface of the button is lifted off the soft surface of the
projection.
=
Figure 1 shows a fly or hopper, having an escapement button mounted on
it in the manner heretofore usual when the fly or hopper carries the escape-
ment button. In this Figure, a is the fly or hopper, 6 the escapement button,
can adjusting screw passing through the fly or hopper a, and having the
escapement button 6 mounted on its end; d is a projection which acts as a
stop to the button. The surface of this projection where the button comes
against it is padded with felt or other soft material; e is the spring of the fly
or hopper.
Figure 2 shows the arrangement ordinarily employed when the button is
mounted on the projection d in place of on the fly or hopper a.
The adjusting
serew c in this case passes through a slot or hole cut in the fly or hopper;
when this latter construction has been adopted, the button has in some
instances been mounted in an inclined position, as is shown at Figure 3.
Now, my Invention consists in mounting the escapement button on the fly
or hopper, and at such an inclination that just as it comes against the surface
of the projection it is moving in a direction perpendicular to that surface.
This arrangement is shown at Figure 4, which shows my improvements
applied to an upright pianoforte action. a is a key carrying the piece b, to

page_text: which the fly or hopper c is jointed at c²; d is the escapement button fixed on
the adjusting screw e, which is screwed into the fly or hopper; f is the pro-
jection or stop for the escapement button. In consequence of the inclination
at which the escapement button is placed just as it comes against the surface
of the projection, it is moving in a direction perpendicular to this surface; this
it will be seen arises from the joint c', on which the fly or hopper turns, being
in the same plane, or nearly so, with the surface of the button and of the pro-
jection; g is a piece called the "sticker," which receives motion from the fly
or hopper, and communicates it to the hammer h.
In
Figure 5 shows my improvements applied to a grand pianoforte action.
this case the fly or hopper acts directly on the hammer butt, as is shown; i is
a piece mounted on the spring i¹ fixed in the fly or hopper, and which is for
the purpose
of facilitating the rapid repetition of the blows of the hammer; the
arrangement of the piece i, however, forms no part of my Invention. jis a
check such as is commonly employed in the action of grand pianofortes.
In witness. whereof, I, the said James Stewart, have hereunto set my
hand and seal, this Ninth day of June, in the year of our Lord One
thousand eight hundred and fifty-nine.
JA SIEWAKI. (L.S.)