IMPROVEMENTS IN THE CONSTRUCTION OF PIANOFORTES
Year: 1863

page_text: LETTERS PATENT to William Glen Eavestaff, of Great Russell Street, in
the County of Middlesex, Pianoforte Manufacturer, for the Invention of
"IMPROVEMENTS IN THE CONSTRUCTION OF PIANOFORTES."
Sealed the 11th September 1863, and dated the 16th March 1863.
PROVISIONAL SPECIFICATION left by the said William Glen Eavestaff*
at the Office of the Commissioners of Patents, with his Petition, on the
16th March 1868.
I, WILLIAM GLEN EAVESTAFF, of Great Russell Street, in the County of
Middlesex, Pianoforte Manufacturer, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE CONSTRUCTION OF PIANOFORTES," to be as
follows:-
My Invention of improvements in the construction of pianofortes relates
to a novel mode of constructing and arranging those parts which are known
as the "action," the object of the improvements being to increase the power
and expression of the instrument. This is effected, in the first place, by causing
the "sticker" or rod which transmits the motion from the key to the hammer
and upper part of the action to rise and fall in a vertical direction, or nearly

page_text: so, whereby greater power of blow is transmitted than in the present construc-
tion of upright actions. To this end, in one arrangement of parts I cause the
sticker or communicating wire or rod to be guided in a vertical direction, or
nearly so, either by using clothed sockets and causing it, if made of wire or a
metal rod, to pass through suitable guides, or I use a double parallel centre
and clothed sockets, or I adapt steadying pins to the sticker or to the arm
containing the hopper, to effect the same object? The hopper, lever, or arm
being rigidly attached to the upper end of the sticker or its equivalent, must
of course rise vertically with the latter and communicate to the hammer
precisely the same kind of blow as is transmitted from the key to the sticker.
I also use the same vertical_motion for checking the rebound of the hammer
after the blow is struck.
Another improvement consists in raising the centre of motion of the keys so
as to bring it either up to the plane of or somewhat above the level of the
point of junction of the key with the sticker or the adjustable pin or button
attached thereto; or I produce the same effect by comparatively depressing
the centre and back rails of the key frame and reducing the back part of the
key in thickness. By this means that part of the key which gives its impetus
to the sticker or its equivalent is then raised in an almost vertical direction
over the space it is required to travel.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Glen Eavestaff in the Great Seal Patent Office on
the 16th September 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
GLEN EAVESTAFF, of Great Russell Street, in the County of Middlesex, Piano-
forte Manufacturer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Sixteenth day of March, in the year of our Lord
One thousand eight hundred and sixty-three, in the twenty-sixth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said William Glen Eavestaff, Her special license that I, the said William
Glen Eavestaff, my executors, administrators, and assigns, or such others as
I, the said William Glen Eavestaff, 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

page_text: 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 "IMPROVEMENTS IN THE CONSTRUCTION OF PIANOFORTES," upon the
condition (amongst others) that I, the, said William Glen Eavestaff, by an
instrument in writing under my hand and seal, 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 William Glen Eavestaff, 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, reference being had to the Drawing
hereunto annexed, and to the letters and figures marked thereon (that is
to say).
This Invention relates to a novel mode of constructing the "action" of
upright pianofortes, the object being to increase the power and facility of
expression of the instrument.
In the accompanying Drawing Fig. 1 is a vertical section of so much
of a pianoforte as will serve to explain the construction of the improved
action; Fig. 2 represents the action slightly modified in form; and Fig. 3
is a further modification. The improvements in the action which I pro-
pose to introduce are, first, the direct thrust of the key upon the hammer
butt, or in other words, the transmission of the motion imparted by the
key to the sticker in a direct line to the hammer butt; and, secondly, a
simple and efficient checking of the hammer as it rebounds from the vibrating
string.
At Fig. 1, a is the finger key, so constructed and mounted as to bring the
bearing surface at the inner end of the key intended to carry the sticker at or
about a level with its centre of motion; bis the sticker, consisting of a cross
piece and two guide rods 6' and 6, the former of which is provided with
adjustable stops, the upper one for limiting the length of movement of the
stricker by striking against the fixed rail c, and the other to regulate the length
of the rod to suit the dip of the key a. These rods work through clothed
sockets carried by the rail c. Upon the sticker 6 is mounted the hopper d,
the hinge or centre of which is in a line with the guide rod b', which rests
upon and receives the blow of the key. The hopper is kept up to a vertical
position by means of a light spring d¹ which presses it forward into contact

page_text: with the butt of the hammer e. The hopper is provided with a tail, which, in
the ascent of the hopper, strikes against an adjustable stop on the "setting-off"
rail f, and thereby trips the hopper, throwing it off the hammer butt. By
this vertical movement of the hopper the hammer will receive a direct vertical
thrust, and thus the pressure of the performer's fingers on the key will be
communicated with the least possible detraction from the force applied. As the
hammer moves inwards under the upward thrust of the hopper to strike the
string g, the hopper, being tripped as explained, falls into the dotted position,
at which moment it is ready to check the rebound of the hammer. For this
purpose it is provided with a segment or other shaped check pad h, which is
carried by a wire projecting from the hopper and held at a suitable angle and
elevated above the hopper. The hammer butt is also fitted with a checking
piece carried by a projecting bent wire. These checking pieces are so
arranged with respect to each other that when the hammer has left the string
and arrived at the dotted position, Fig. 1, the cushion h will receive the check
piece on its face and effectually check all tendency in the hammer to
rebound; at the same time, immediately on the removal of pressure from the
key a the cushion h will recede and leave the key free and ready to repeat its
blow on the repetition action of the key. The perfection of this checking
action depends principally on the maintenance of the relative motions of the
two checking pieces, the arrangement shewn in the Drawing effectually pre-
venting the locking of the parts.
Fig. 2 shews a modification in the construction of the sticker, but in other
respects this arrangement is similar to that above described.
The sticker b, instead of preserving its horizontality while rising by means
of two guide rods, is fitted only with one rod b¹ which carries adjustable stops
and bears upon the end of the key, as before described. The sticker is con-
nected to the rail c by means of a link 6* which, by providing a double-joint
coupling, ensures the maintenance of the horizontality of the sticker and the
consequent direct vertical thrust of the hopper. The centres of the joints will
be in all cases clothed to prevent sticking and rattling.
Fig. 3 shews the arrangement of the sticker to suit a cabinet pianoforte.
In this case the sticker 6 is elongated and is fitted with steadying pins b', b³,
and 6s, which, passing through clothed guides in the rails c, steady the sticker
in its vertical movements.
Having now set forth the nature of my Invention of improvements in the
construction of pianofortes, and explained the manner of carrying the same
into effect, I wish it to be understood that, under the above in part recited

page_text: Letters Patent, I claim the means above described for operating and checking
the hammers of vertical pianofortes.
In witness whereof, I, the said William Glen Eavestaff, have hereunto.
set my hand and seal this Sixteenth day of September, in the
our Lord One thousand eight hundred and sixty-three.
year of
Witness,
J. W. MOFFATT,
66, Chancery Lane.
W. G. EAVESTAFF. (L.s.)