AN IMPROVED ACTION FOR PIANOFORTES
Year: 1870

page_text: LETTERS PATENT to William Glen Eavestaff, of Great Russell Street,
in the County of Middlesex, Pianoforte Manufacturer, for the
Invention of "AN IMPROVED ACTION FOR PIANOFORTES."
Sealed the 9th May 1871, and dated the 23rd November 1870.
PROVISIONAL SPECIFICATION left by the said William Glen Eavestaff
at the Office of the Commissioners of Patents, with his Petition,
on the 23rd November 1870.
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 "AN IMPROVED ACTION FOR PIANOFORTES," to be as
follows:
:~
The object of this Invention is to increase the power and expression
of upright pianofortes and to render the action less sensitive than here-
tofore to atmospheric changes. In order to attain these objects I cause
the sticker or conducting rod which transmits the motion from the
finger key to the hammer butt to rise and fall in a vertical direction

page_text: or nearly so, and I secure this motion by the use of radius rods or
hinged pieces which serve to connect the sticker or conducting rod
to the framing of the instrument. Mounted on the top of the sticker
is the hopper, which when in its quiescent position is slightly inclined
towards the hammer butt, so that when it rises with the sticker to put
the hammer in action, the tendency will be for it to move into line
with the sticker and to strike the butt in the direct line of the stickers
motion. The radius rods which support the sticker constitute a parallel
motion, but by a little adjustment of one or other of these rods, a
slight oscillating motion may be given to the sticker as it rises in order
to compensate for the irregular motion imparted to the sticker by the
rocking of the key. I also use the same vertical motion for effecting
the rebound of the hammer.
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 23rd May 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
GLEN EAVESTAFF, of Great Russell Street, in the County of Middlesex,
Pianoforte Manufacturer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-third day of November, in the
year of our Lord One thousand eight hundred and seventy, in the thirty-
fourth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said William Glen Eavestaff, Her special
licence that I, the said William Glen Eavestaff, my executors, adminis-
trators, 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 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
"AN IMPROVED ACTION FOR PIANOFORTES," upon the condition (amongst
others) that I, the said William Glen Eavestaff, my exccutors or admi-
nistrators, by an instrument in writing under my, or their, or one of

page_text: 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 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) :-
The object of this Invention is to increase the expression of upright
pianofortes and to render the "action less sensitive than heretofore to
atmospheric changes. In order to attain these objects I employ a new
arrangement of the "action" for which I obtained Letters Patent bearing
date the Sixteenth March, One thousand eight hundred and sixty-
three, which arrangement enables me to ensure that the sticker shall
properly operate in transmitting the motion from the finger key to the
hammer butt.
In the accompanying Drawing Fig. 1 is a side elevation of the
improved action in its normal or quiescent position, and Fig. 2 is a similar
elevation shewing the finger key depressed and the action in the
position it will take the moment after striking the strings in front of
the hammer.
In these Figures A is the finger key; B, the sticker; C, the hopper
mounted on the top of the sticker; D, the hammer; E, the damper; and
F, the strings. Instead of supporting the sticker B by causing it to
work through fixed guides as in my former Patent, which guides inter-
fered with its free working when the instrument was subjected to a
damp atmosphere and thereby destroying the sensitiveness of the "action"
I now support the sticker by means of radius rods or hinged pieces b
which are hinged or jointed thereto, and are similarly connected to
pieces 6 made fast to the framing of the instrument. The hopper C
which is jointed to the top of the sticker is provided with a rigid tail
piece C for striking against an adjustable stop piece c which as the
hopper rises to throw the hammer against the strings trips the hopper
from the hammer butt and allows it to rebound. Made fast to the tail

page_text: piece C¹ is a wire G which carries at its upper end a cushion G¹ for
checking the rebound of the hammer. The hammer D is mounted as
usual on the hammer rail and its butt D' is connected with the hopper
by means of a spring d which yields to allow the hammer to deliver its
blow but which so soon as the hopper has been tripped from under the
hammer butt will serve to hold back the hammer from the strings.
Fitted to the rear of the hammer butt is the check piece D' which on
the rebound of the hammer is caught on its inner faces by the cushion
G', as shewn at Fig. 2.
It will be understood that as the perfection of this checking "action"
depends principally on the maintenance of such relation between the
two checking pieces as will ensure their proper contact at the right
moment without allowing of a locking of the parts, it is important to
provide ample means of adjustment for one or other of these pieces, and
it is for this reason that I have mounted the cushion G¹ on the rod
G which from its length and vertical position permits of a large
latitude of adjustment. By referring to Fig. 1 it will be seen that the
hopper when in its quiescent position is slightly inclined towards the
hammer butt so that when it rises with the sticker to put the hammer
in action the tendency will be for it to move into line with the sticker,
and to strike the butt in the direct line of the sticker's motion. The
radius rods b, b, or their equivalent hinge pieces which support the
sticker constitute a parallel motion, and they may be both on one side
of the sticker as shewn in the Drawing, or one on either side, without the
proper working of the sticker being affected by the change of position,
and by a little adjustment of one or other of these rods or their equi-
valents a slight oscillating motion may be given to the sticker as it rises
in order to compensate for the irregular motion imparted to the sticker
by the rocking of the key.
Having now set forth the nature of my Invention of "An Improved
'Action' for Pianofortes," and explained the manner of carrying the same
into effect I wish it to be understood that I do not claim as of my
Invention the supporting of stickers by means of radius rods or hinged
pieces, neither do I claim the mounting of hoppers upon the ends of
stickers generally irrespective of the manner in which the stickers are
supported, but what I claim under the above in part recited Letters
Patent is, the combination of parts above described whereby I am

page_text: "
enabled to ensure a more rapid repeat in the . " action of upright
pianofortes than has been hitherto attained and to render the same less
sensitive than heretofore to atmospheric changes.
In witness whereof, I, the said William Glen Eavestaff, have here-
unto set my hand and seal, the Twenty-second day of May, in
the year of our Lord One thousand eight hundred and seventy-
one.