IMPROVEMENTS IN MECHANISM FOR PIANOS
Year: 1881

page_text: PROVISIONAL SPECIFICATION left by Frank Wirth at the Office of the
Commissioners of Patents on the 13th September 1881. A communication
from Gottlob Philipp, of Forst-in-der-Lausitz, in the Empire of Germany.
FRANK WIRTH, of the firm of Wirth and Company, Patent Solicitors, at
Frankfort on the Main, in the Empire of Germany. "IMPROVEMENTS IN MECHANISM
FOR PIANOS." [A communication from Gottlob Philipp, of Forst-in-der-Lausitz, in
the Empire of Germany.]
This Invention relates to pianoforte mechanism, and comprises various novel
features, the nature of which is hereinafter described.. and illustrated in the
accompanying Drawing, in which Figure 1 represents my improvements as applied
to an upright piano, and Figure 2 my improvements as applied to a horizontal
piano.
The first part of my said Invention consists in a combined check and repeater
device constructed and arranged as follows, that is to say, a bar a is fixed on the
lever C (Figure 1), and upon the lever C (Figure 2), and serves to effect the
release of the hammer by pressing upon the screw e and thereby moving the jack
or hopper d at or near the termination of the stroke, so as to ensure precision and
force in the blow. The bar a in the return or downward stroke rapidly moves away
from the said screw to allow the mechanism to act freely. At f there is a spring
which presses (when the lever C₁ recedes) the jack or piece d into its original
position, and this spring serves for maintaining the same in its proper place.
This mechanism entirely adapts itself to requirements, as it causes the jack d to
repeat (during rapid performance) when the key recedes, even very slightly, whilst
when the performance is slow the said mechanism will effect the repetition very
gently, so that no rapping or violent concussion can take place below where the
cushion is provided at b. A coupling z (Figure 1) prevents (in upright pianofortes)
the disadvantageous sudden separation of the butt from the jack. The regulation
takes place by a screw g having an "eye" or loop. The friction is reduced to a
minimum, and as there is no possibility of the movable parts becoming separated
from one another the necessity for subsequent regulation is altogether avoided.
The second part of the taid Invention consists in means hereinafter described
for regulating and actuating the damper froin the front by means of a jack; also
in the arrangement of an independent forte-stop placed in front of the action of
an upright piano.

page_text: The bar (Figure 1) presses the jack h backward, whereby the arm n provided
with the screw causes the wire-lever m to move downward, thereby withdrawing
the damper. The regulation of the damper is effected from the top, the screw?
being actuated for this purpose by a wire-hook. The forte-stop i (actuated from
the pedal) simply presses upon the wire-lever m and causes the damper to be
lifted.
The third part of my Invention consists in the arrangement of a simple jack
designed to work with the slightest possible friction, and being placed independently
of the other parts in double actions for upright pianos, and provided in horizontal.
pianos for allowing the key to be withdrawn freely.
The block O¹ (Figure 1) has at a lined opening, and the jack p' is movably
attached to the lever C, and at its lower part has a pin which freely moves in the
opening at x with very slight friction. In horizontal actions to the hopper C"
(Figure 2) the jack pl is fixed by means of parchment or by a pivot, and its lower
end rests on the block O" in the cushioned depression or indentation, and is held
in this position by lugs q, q, q. This arrangement allows the key to be removed
and replaced without any difficulty.
The fourth part of my Invention consists in the arrangement of a check, which
acts rapidly and directly at the end of the blow for upright piano-forte actions
and in the provision of a check in horizontal piano-actions, so arranged that the
key may be readily removed when desired.
The inclined end of the bark and of the piece h (Figure 1) cause the piece h to
move slowly at first and then rapidly, and thus the check piece r fixed in the piece h
moves rapidly and catches the hammer when the same is released.
When applied
to horizontal pianos the check-piece r is attached to the lever C" (Figure 2), and
the key can thus be removed without obstacle.
The fifth part of the said Invention consists in the arrangement of a spring
entirely independent of the moving parts for counteracting at will the gravity of
the hammer in horizontal piano actions.
In the picces (Figure 2) in which the piece t of the hammer moves is fixed a
spring u, the long end of which presses upward (by means of the jack or hopper d)
upon the piece t; the tension of the said spring can be varied at will by the set-
screw v. This spring has for its purpose not only to counterbalance directly the
gravity of the hammer so as to provide for softness or delicacy in the blow, but it
also serves indirectly to reduce the wear of the leather on the hammer butt.
The sixth part-of-the-said-Invention consists in devices for use in horizontal
pianoforte mechanism for permitting the playing of as soft a pianissimo as desired,
whilst retaining the utmost power of tone and without shifting of the hammer-
board, thus avoiding friction.
The lever or piece w (Figure 2), which in its movements exactly corresponds with
those of the hammer, prevents the friction which takes place in other methods;
it is simply raised through a jack by means of a pedal as high as may be necessary,
whereby the impact of the hammer and consequently. the tone become softer; the
hammer however strikes always at the same point, and thus the slurring of the
tone caused by shifting is avoided.