IMPROVEMENTS IN PIANOFORTES AND SIMILAR INSTRUMENTS
Year: 1883

page_text: LETTERS PATENT to Herbert John Haddan, of Kensington, Middlesex for an
Invention of IMPROVEMENTS IN PIANOFORTES AND SIMILAR INSTRUMENTS
:
a communication to him from abroad by A. Biese, of Berlin, and G. Zierold,
of Leipzig, both in the German Empire
PROVISIONAL SPECIFICATION left by the said Herbert John Haddan at
the Office of the Commissioners of Patents on the 1st March 1883..
HERBERT JOHN HADDAN, of Kensington, Middlesex, "IMPROVEMENTS IN
PIANOFORTES AND SIMILAR INSTRUMENTS," a communication to me from abroad, by
A. Biese, of Berlin, and G. Zierold, of Leipzig, both in the German Empire,
This invention relates to pianoforte actions and to the method of attaching the
soundboard.
.
The mechanism comprises a pusher connected with the key, and adapted to act
on a downward projection of the hammer bar by means of a spring attached to the
said bar, the pusher being preferably hinged to a lug fixed to the key.
The said projection of the bar has an oblique face and is lined with leather,
which lining is made adjustable by means of a screw for the purpose of releasing
the hammer more or less rapidly. The hammer is hinged at its rear end to a
fixed rail,
I also place the sounding board between two iron frames provided with ribs and
adjustable screws, serving to vary the tension of the frames.
The two frames are held together by rews, and the ribs are further connected*
by a cross rail or bar,
:

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Herbert John Haddan in the Great Seal Patent Office on the
1st September 1883.
HERBERT JOHN HADDAN, of 'Kensington, Middlesex,
"IMPROVEMENTS IN
PIANOFORTES AND SIMILAR INSTRUMENTS" a communication to me from abroad, by
A Biese, of Berlin, and G Zierold of Leipzig, both in the German Empire
This invention has for its principal object to raise the power of sounds of pianos,
and consists chiefly in the striking mechanism and arrangements of the sounding
board.
The mechanism for striking the chords has special particularities, as shown in
the accompanying drawing sheet L. The key A carries the push-rail C to which is
secured the pusher B with a hinge c.*
The bar of the hammer D, hinged to the hammer rail E, is made of one piece,
and is provided with a neck G for the pusher. The hammer bar carries moreover
the spring f, the end of which presses on the protuberance i of the pusher. The
neck G is covered with a leather made adjustable by a screw 8. The catcher h
stops the hammer, when falling. The working of this mechanism is as follows:
By touching the key the pusher B pressed against the neck by the spring f is
raised; thereby the hammer is thrown up. After having come in contact with
the chord the hammer falls only a little, being caught by h, during which time the
spring fis again pressed against the lower part of the neck G.
To regulate the release of the pusher from the neck G of the hammer, the leather
of the neck is pressed more or less towards the pusher by the screw 8, whereby
the pusher emerges sooner or later from below the neck G during the depression
of the key, so as to allow the hammer to fall.
In order to obtain more powerful sounds from the piano and at the same time
to prevent any influence of humidity or changes of temperature on the tension of
the sounding board the latter is fastened in the way indicated in the accompanying
drawing, sheet II, Figs 1 to 10. The sounding board A is placed between two
iron frames B and C, the frame B having a groove or iron seat in which the
sounding-board A is placed. The frames B and C are provided with various ribs
affording greater stability to the whole and adapting the frame to be set in tension
by means of the screw 8. The insulation of the sounding board from the flange Z
increases the intensity of the sounds.
The frames B and C are fixed together by means of screws e.
The ribs h are
provided with notches g into which fits the bar f, whereby solidity of the whole
structure is increased and moreover a clinking of the iron frame prevented.
The special arrangement of the ribs, the position of the screw s, and the arrange-
ment of the stays m_may be varied according to the size and nature of the sounding
board or the piano.

page_text: or later by adjusting the screws acting on the leather lining of the neck,
substantially as described.
2.) The arrangement of the sounding board A between two iron frames B and C,
substantially as described.
In witness whereof I, the said Herbert John Haddan have hereunto set my
hand and seal this twenty-ninth day of August A.D 1883.
HI HADDAN (20)