AN IMPROVED PIANOFORTE ACTION OR STRING SOUNDING MECHANISM
Year: 1856

page_text: LETTERS PATENT to Timothy Gilbert, of the State of Massachusetts,
of the United States of America, for the Invention of "AN IMPROVED
PIANOFORTE ACTION OR STRING SOUNDING MECHANISM."-A communication
from Daniel H. Shirley, a Citizen of the United States, the Inventor
thereof.
Sealed the 2nd December 1856, and dated the 10th October 1856.
COMPLETE SPECIFICATION filed by the said Timothy Gilbert at the
Office of the Commissioners of Patents, with his Petition and Declaration,
on the 10th October 1856, pursuant to the 9th Section of the Patent
Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME,
BE IT KNOWN, that I, Timothy Gilbert, of the State of Massachusetts,
of the United States of America, do hereby declare the nature of the Inven-
tion of "AN IMPROVED PIANOFORTE ACTION, OR STRING SOUNDING MECHANISM,"
(as communicated to me by Daniel H. Shirley, a Citizen of the United States,
and resident therein,) as well as the manner in which said Invention is to be
performed or constructed, to be fully described and represented in the follow-
ing statement and in the accompanying Drawing, wherein such is exhibited in
Figures 1 and 2 under two methods of constructing and arranging the same,
and as applied to a pianoforte hammer and its lifter; like parts on such
Figures being denoted by like letters.

page_text: 46
To so simplify a pianoforte action as to render it cheap in construction, to
prevent blocking" of the hammer at improper times, to avoid as far as
possible the necessity of regulating or readjusting the operative parts with
respect to one another, and at the same time to obtain a powerful action and
secure to it ease of operation and delicacy of touch, are some of the objects
I have aimed at, and have secured in the action or mechanism containing my
improvement. In the same, the jack or fly, as commonly used in pianoforte
actions, is dispensed with, the devices employed for elevating the hammer
being so arranged and actuated as to always maintain upon the key lever the
weight of said hammer while it is in action, the same rendering the hammer
sensible to the slightest downward movement of the key in whatever position
it may be when so moved, or is made to receive a blow or downward pressure
from the finger of a performer. Furthermore, by my improvement, the back
catch of the hammer will be operated to great advantage, so far as concerns
arresting the movement of the hammer after a blow from it upon its string
has been produced.
a, a, in the Drawing represent the key lever; b, the hammer; and c, its
arm, which is hinged to the hammer rail d in the usual way. Hinged to the
hammer arm or otherwise properly applied to it, and near the rail d, is a short
vertical post or arm e (or its equivalent), which is connected to an inclined
arm or lever f, that should play vertically on a fulcrum or pin disposed as
seen at g, the same being arranged on an extension of the rail d, or in a
separate supporting piece or rail. To the other end of the arm ƒ a small
block h, having its working edge bevelled or otherwise suitably formed, is
applied so as to rest on and operate in connection with a lifter or but l, which
is fastened on a lever i that is hinged to the key lever a, a, or turns upward
and downward upon a pin arranged as shown at k, and within a projection
from the lever a, a. The other end of the lever i supports the back catch m,
whose shank extends upward from it, and in respect to the hammer, as shown
in the Drawing. When the key is struck for the purpose of elevating the
hammer, the but or lifter 1 will act against the small block h in such manner
as to raise it, whereby the inclined arm f and the hammer will be forced
upward simultaneously, so as to cause the hammer to approach and give a
blow to its string. By reason of the peculiar manner in which the hammer
is applied to the lifter or but 1, the weight of the hammer will be maintained
on the but during such time as it may be necessary or desirable to elevate the
hammer towards the string, the same rendering the hammer very susceptible
to any upward or downward movement of the key lever. By reason of the
but I and the back catch m being connected with the key lever by a separate

page_text: lever i, the back catch, immediately after a blow of the hammer against the
string, will be elevated so as to arrest and hold the hammer or prevent it from
rising until the front end of the key lever is again struck downward, the back
catch being raised by the action of the block h against the adjacent corner of
the lifter at or near the termination of the upward movement of the said
lifter.
By the above-described or an equivalent arrangement of the afore-
mentioned devices for operating the hammer, it will be seen that when they
are once properly adjusted to one another, little or no readjustment of them
will be necessary under ordinary circumstances. As the arm falways serves to
maintain the block h in proper position on the lifter 1, the hammer is kept in
readiness for a blow, whatever may be its position relative to the string. The
advantage of this when a note is to be repeated, "trilling" to be effected, or a
powerful blow given to the string, readily will be apparent, the possibility of
improperly "blocking" the hammer being effectually guarded against; there-
fore when the lifter or its equivalent is made to operate either directly or
indirectly against an inclined arm for any analogous contrivance applied under
the hammer to elevate the same.
I claim the above-described peculiar manner in which the back catch m and
the lifter 1, or its equivalent, are combined together and with the key lever,
viz., by a lever i hinged to the key lever and fastened to both back catch and
lifter, the whole being substantially in manner and productive of advantages,
as herein-before set forth.
In testimony whereof, I have hereunto set my signature and seal, this
Twenty-sixth day of September 1856.
TIMOTHY GILBERT. (L.S.)