CERTAIN IMPROVE-; MENTS IN THE CONSTRUCTION OF PIANOFORTES
Year: 1867

page_text: LETTERS PATENT to William Edward Gedge, of the Firm of John Gedge
and Son, of Number Eleven, Wellington Street, Strand, in the County
of Middlesex, Patent Agent, for the Invention of "CERTAIN IMPROVE-;
MENTS IN THE CONSTRUCTION OF PIANOFORTES." -A communication from.
abroad by Francis Pivoda, of Prague, in the Empire of Austria, Pianist
and Composer.
Sealed the 3rd May 1867, and dated the 6th March 1867.
COMPLETE SPECIFICATION filed by the said William Edward Gedge at
the Office of the Commissioners of Patents, with his Petition and
Declaration, on the 6th March 1867, pursuant to the 9th Section of the
Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM,
EDWARD GEDGE, of the Firm of John Gedge and Son, of Number Eleven,.
Wellington Street, Strand, in the County of Middlesex, Patent Agent,. send
greeting.
WHEREAS I am in possession of an Invention for "CERTAIN IMPROVEMENTS
IN THE CONSTRUCTION OF PIANOFORTES," and have petitioned Her Majesty to
grant unto me, my executors, administrators, and assigns, Her Royal Letters
Patent for the same, and have made solemn Declaration that the said

page_text: Invention is a communication to me from abroad by Francis Pivoda, of
Prague, in the Empire of Austria, Pianist and Composer.
NOW KNOW YE, that I, the said William Edward Gedge, do hereby
declare that the following Complete Specification, under my hand and seal,
fully describes and ascertains the nature of the said Invention, and the
manner in which the same is to be carried into practical effect (that is to
say):
Many pianoforte makers have endeavoured to construct a mechanism
capable of effecting mechanically the transposition into the different musical
The
modes or tones, but they have laboured hitherto without success.
removal of the rows of keys has always been considered as the most simple
means of attaining that end, but all experiments have been thwarted by an
indispensable arrangement composed of two or three strong iron bars fastened
between the cross beam to which the strings are attached and the hind part
of the pianoforte in order to prevent the highly strained metal strings from
displacing the said cross beam. The places occupied by the said bars of
support interrupt the uniformity of the series of strings, leaving interstices, as
it is impossible to draw strings in those places. It is a matter of course that
two or three strings sounding sympathetically are considered as one string.
As each string is touched by a hammer it is evident that there are as many
hammers as strings, and that the series of hammers must be divided exactly as
the series of strings, consequently the said interstices determined by the
iron bars in the series of hammers must correspond with the series of strings,
or strings are suspended above hammers and interstices of the series of strings
above the corresponding interstices of the series of hammers. It is sufficient
to cast a glance upon the arrangement of a pianoforte to perceive that it is
impossible to effect the transposition by shifting the keys of any of the
mechanisms hitherto made use of in the construction of pianofortes, because
each of the iron bars would be touched by some hammer, while in the
neighbourhood of the said bars there would be some strings which being
suspended above the interstices of the series of hammers could not be made to
sound.
After numerous experiments Mr. Pivoda has invented a very simple
mechanism by means of which the removal of the keys by one, two, three, or
more semitones upwards or downwards, and consequently the transposition
nto the different musical modes may be effected; this new mechanism is
applicable to all pianofortes, both of English, French, and German construction;
the said bars of support are no more an obstacle because in this system the
keys only are shifted, but the hammers remain fixed. The series of hammers

page_text: being an independent part of the mechanism must be separated from the row
of keys and be conveniently fastened in the pianoforte.
The annexed Sheet of Drawings forming part of this Complete Specification
shows the application of the improvements, the subject of this Invention, to a
pianoforte of German construction. The hammers are moved upwards by
special rods which the player does not touch directly.
Figure I. represents the connection of the hammer a with the rod b; the
series formed by the corresponding number of such connections of the hammer
with the said rod constitutes the "hammer rail." The series of rods A.
(Figure II.) is arranged in conformity with the series of strings with the
interstices c, c, corresponding with the bars of support, but the ends of the
rods B are cut so as to form a uniform and continuous row. Into this uniform"
row of rods are inserted the pins d (Figure I.) conducting them downwards
through a bracket e, so as to form also a uniform and continuous row. Under
the said row of pins I place the keys C (Figure II.), the series of which must
correspond with the row of the pins d and not with the series of strings,
consequently the said series of keys must be arranged in a perfectly uniform
manner. Now the uniformity of the row of pins d and of the corresponding
series of keys permits the easy and rapid removal of the latter, and in shifting
the keys by one, two, three, or more semitones upwards or downwards the
transposition into the different musical modes can be effected. It is evident
that in consequence of the removal of the row of keys each key must be placed
under a pin d. The Figure II. represents partially the row of rods A with
their cut ends B; the removable keys C placed under the said rods are
entirely shewn. The Figure. I. shows that each rod has its bammer. The
Figure III. is a detailed view of the key f; the Figure IV. shows the action
of the key on the rod b and on the hammer a by means of the said pin d
traversing the bracket e. The transposition effected by this simple mechanism
cannot be prejudicial to the sound of the pianoforte, for this Invention is
founded on the principle that the hammers are a fixture while the row of keys
can be shifted at pleasure. Many methods may be employed for operating
the removal of the row of keys. The Inventor proposes the arrangement
represented in Figure V. and employed in the instruments which he has
caused to be constructed. A metal rack h, h, is fitted in the front band of
the frame g, g, of the row of keys and fastened by means of screws i, i. A
disk k, k, of about seven inches diameter is fitted under the bottom of the
pianoforte so as to be easily reached by the player's hand. The centre of.the
said disk is in close connection with the centre of the small toothed wheel /.
The player who desires to make a transposition puts his hand under the

page_text: bottom of the pianoforte and turns the disk k, k, to the right or left hand by
means of a knob fitted on the said disk. In consequence of this movement
the rack h, h, and the row of keys C (Figure II.) are shifted by means of the
small toothed wheel (Figure V.) Between the two usual pedals is a third
pedal leading to a wooden stud intended to keep the keys steady. The player
who wishes to transpose treads the middle pedal down and raises his foot when
he has shifted the keys as much as he desires, which he may ascertain on a
graduated line or scale fitted above the keys. The side cheeks m, m.
(Figure II.) of the keys are hollow and receive the keys which disappear
on the right or left hand by the effect of the removal. Indeed, next to one
of the said cheeks a gap or interstice arises comprising as many keys as have
disappeared in the other cheek in consequence of the removal, but the
Inventor has remedied that inconvenience by placing some keys also under the
said two cheeks, so that the same number of keys comes out of one cheek as
disappear on the other side. The keys passing over the hollow space of the
check are received in a recess made in the board of the pianoforte, so that the
row of keys has always an extent of seven octaves.
Having now described the improved pianoforte mechanism the subject of
this Invention, and the means by which it is to be worked, I claim as the
Invention communicated to me as aforesaid,-
Firstly, the separation of the system of hammers from the row of keys (sec
Figure I. side view of a pianoforte of German construction).
Secondly, the independent application and fastening of the system of
hammers in the pianoforte.
Thirdly, the double division of the row of rods, namely, upwards with the
interstices c, c, (Figure II.) corresponding with the series of strings and down-
wards with the pins d inserted in the uniform and identical ends of the rods,
as before described.
In witness whereof, I, the said William Edward Gedge, have hereunto
set my hand and seal, this Fifth day of March, in the year of our
Lord One thousand eight hundred and sixty-seven.
W. E. GEDGE. (L.S.)