Year: 1888

page_text: Date of Application, 28th Apr., 1888
Specification Accepted, 6th July, 1888
I, FERDINAND SCHAAF of Frankfort on the Maine in the Empire of Germany,
Mechanician do hereby declare the nature of this invention and in what manner the
same is to be performed, to be particularly described and ascertained in and by the
following statement :--
This invention has for its object to make a piano which with the exterior of an
upright piano unites the advantages of a grand piano.
For obtaining the full and free sound of a grand piano, keys or flaps are applied
by which the whole instrument is automatically opened as soon as the key-lid is
unlocked.
For this purpose the instrument is provided on the front and back with flaps K
extending horizontally over the whole length of the piano (Fig. 1).
These flaps are made of fine wooden bands strengthened by metallic bars and turn
round an axis A (Fig. 2).
A second axis B is joined with vertical rods L L'.
The weight of these bars effects an over weight of the flaps on one side and
therefore an opening of them.
The automatic closing of the flaps is obtained in the following manner.
A lever H
is situated on the side of the keys of the instrument and is jointed at one end to the
rods L L whilst the other end is pressed down by the key lid T as soon as the
instrument is closed.
The rod L is also in connection with the lever H¹ of the pedal P (Fig. 3).
As soon as the key lid T is closed the rods L. L' will be lifted and consequently
the flaps K are closed.
The same will be obtained by a pressure upon the lever H', during the play. The
closing of the flaps by the pedal effects a damping of the sound. This damping
action is made more effective by the lifting of the hammers H a (Fig. 4) by the
movable hammer bar H which bar is raised at the same time by the vertical rod L.
If the instrument is closed by the key-lid T the pedal P remains in its position
retained by a spring.
To make the sound of the piano still more resemble the sound of a -grand-piano,
also if the instrument is placed near a wall, the back of it is inclined so that between
the upper part of the instrument and the wall an open space is formed which allows
the free expansion of the sound.
This inclined back of the piano is also provided with flaps which are closed
simultaneously with the flaps of the front side by means of the levers H and H³.
(Fig. 4) shews the mechanism of the instrument. .

page_text: Through the inclined position of the back, the strings also will have an inclined
position. Consequently the hammer Ha is also more inclined so that it after striking
against the strings falls easily backwards by its own weight as in a grand piano.
This construction offers also the possibility to apply a mechanism by which an easy
play and repetition can be obtained. The lever Sc is turned with its axis to the
front of the instrument. In this lever is fixed the wire d for lifting the damper the
wire g for catching the hammer and the lever R bent by a spring for the repetition of
the hammer R is fixed by the nut m to the same height as the Sticker S. t and
follows the hammer as soon as S. c. is raised until it is restrained by the wire i.
The hammer H a failing back with its whole weight bends the lever R down until
it is arrested by the stopper o fixed on the screw o. The hammer Ha will stay in
this position held by the lever R until the Sticker S. t. has arrived again under the
hammer preparing it for a new shock.
The loosening of the Sticker is made by the stopper Ku.
The damping of the strings is effected under the point where the hammer strikes
against the strings by the damper U. If on the place where the strings are
crossed the space is too small the damper must act above the point where the
hammer strikes.
The dampers are lifted by the triggerwire d and fall back by their own weight.
Corresponding to the sound the strings are also thickened and consequently
stronger pegs must be employed. However it is only possible, to make the pegs
stronger on that part where they are placed in the wood as their upper parts must be
thinner to give place for the strings.
The hole in which the string is placed is therefore pierced into the thicker end of
the pegs W. (Fig. 1) and the strings are coiled round the thinner ends of the pegs
beginning from below.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what. I
claim is.
1. An upright piano with an inclined back provided with long horizontal flaps K
on the front and back which are in communication with the vertical rods L. Li and
the levers H. H¹ H³ H³ (Fig. 1) which are opened by the weight of the rods and
automatically closed by the fermeture of the key-lid T and a pressure upon the
pedal P.
2. In the piano formerly described the application of a moveable horizontal
hammer-bar H for lifting the hammers automatically by means of the rod L.
3. In the above described piano the application of a repetition mechanism
composed of the lever Sc with its axis turned to the front of the instrument in
combination with the lever R bent by a spring the lift of which is limited by a wire i
in communication with the kicker S. t. loosened by the stopper K u in combination
with an inclined position of the hammer H. a resulting from the inclined back of the
instrument.
4. In combination with the above described mechanism the application of the
dampers and U acting above and below the point where the hammer strikes upon
the strings lifted by the trigger d and falling back by their own weight.
5. In the above described piano the application of pegs composed of a thicker
and a thinner part. The thicker end being fastened in the wood and serving to
receive the hole in which the strings aré fastened.
TL0011 A 1 1000
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