IMPROVEMENTS IN PLANO-FORTES
Year: 1880

page_text: PROVISIONAL SPECIFICATION left by Henry Witton at the Office of the
Commissioners of Patents on the 5th May 1880.
HENRY WITTON, of Hanover Street, Islington, in the County of Middlesex,
Piano-forte Maker. IMPROVEMENTS IN PLANO-FORTES."
"
The Invention has for its object improvements in pianofortes and relates,-
Firstly. To an improved method of centring the key, whereby I reduce the friction
of the key upon its centre pin and against the lever, whilst I obtain greater facility
for levelling and removing the key. For this purpose, instead of causing the key
to rest at its underside on the cloth or felt washer, and employing the centre pin
only to steady the key and keep it in position, as heretofore, I cause such key to
be supported at or near its upper surface upon the top of the centre pin, and I form
the slot to fit the centre pin in the lower part of the key instead of in its upper
part, whereby I greatly steady the key and reduce its liability to become loose; I
adjustably fix the bearing piece in the key to facilitate the levelling thereof.
of
The Invention relates, secondly, to improvements in the "sticker action
piano-fortes, whereby I reduce friction, obtain certainty of action in escapement and
recovery, combined with economy in construction.
lever,"
For this purpose, instead of employing the ordinary "hopper" and "
I cause the key to act upon a horizontal or nearly horizontal lever, which is
centred or hinged to a vertical or nearly vertical lever, which latter is centred or
hinged at or near its further extremity to a rail extending across the instrument.
To one end of the horizontal lever is flexibly connected the sticker, whilst the other
end thereof is connected by a tape or other flexible connection to an adjustable
lever pin projecting forwards from the damper between the hammer shanks, thereby
removing the damper from the wire by acting thereon from the front of the
hammer rail instead of from the back thereof, as has heretofore been the case in that
class of damper know as the "under damper." The escapement is obtained by
causing the key or a projection from it to act upon a projection or arın from
the vertical lever, thereby moving the horizontal lever endwise, and so causing
the " nose thereof to fall down off the part of the key operating the same.
The "check" is obtained by means of a regulating pin and button held in a diagonal
direction in the sticker and acting upon a rail placed behind the stickers, or
by a similar pin and button held by the lever rail and acting upon an incline
formed on the sticker. In each case it is brought into action by the escapement
"

page_text: before described. The recovery is effected by a spring acting upon the vertical
lever, and is facilitated by a projection of the horizontal lever beyond the nose
thereof, which projection is supported by the "carriage" of the key, or by projections
from the key or by the key itself, which in such latter case is shaped to fit. By
these means great power of repetition is obtained.
My Invention also relates to improvements upon an Invention for which Letters
Patent were granted to me, dated July 7, 1877, No. 2626, and consists in applying
to the action therein described modifications of the foregoing damper action
and escapement.
For this purpose I centre or hinge a horizontal or nearly horizontal lever to the
lower part of the "lever" rail, and to such lever I fix an arm which acts against an
adjustable button carried by the "hopper fly;" the under damper is removed from
the wire by a tape or other flexible connection attached to one end of the before
mentioned horizontal lever, or where the aforesaid percussive action is not used
such flexible connection is attached to a projecting end of the "lever" of the action.
My Invention also relates to improvements in the back framing of piano-fortes,
and is especially applicable to iron front frames, whereby I gain greater purity of
tone, greater support to the wrest plank, and facility for re-stringing.
In carrying this part of my Invention into effect I dispense with the upper wood
bridge or iron bridge and bearing bar heretofore employed, and I place the
wrest plank in an inclined position corresponding with the bearing required
for the wires on the upper bridge, and I shape it in a similar manner to the
upper bridges now in use, the edge forming the bearing for the strings. This
edge is faced with ivory or other hard material other than metal to prevent
the wires cutting in, and is pinned in the manner ordinarily adopted for the
bridges.
The possibility of splitting by the pins is prevented by forming the wrest plank
with the grain of the wood crosswise thereof.
The endway grain of the wood of the wrest plank forms a solid abutment
for the iron frame, which is brought up close underneath the bridge pins and
is adjusted to within a short distance of the wires, thereby affording the greatest
possible support to the wrest plank.