Improvements in the Construction of Pianofortes and other similar Musical Instruments.
Year: 1888

page_text: Date of Application, 2nd Aug., 1888
Specification Accepted, 5th Oct., 1888
COMPLETE SPECIFICATION.
Improvements in the Construction of Pianofortes and other similar
Musical Instruments.
I, CARL DOMINICUS NEHAMMER, of No. 16 Frederiksberggade, in the City of
Copenhagen, Denmark Pianoforte Manufacturer do hereby declare the nature of my
Invention for "IMPROVEMENTS IN THE CONSTRUCTION OF PIANOFORTES AND OTHER
SIMILAR MUSICAL INSTRUMENTS" and in what manner the same is to be performed, to
be particularly described and ascertained in and by the following statement :-
The essential feature in the construction of stringed musical instruments, that is,
the quality and durability of the tone, has been sought to be obtained in the
manufacture of pianofortes, by the application of the most varied devices, and
especially so by employing different constructions of iron frames.
Up to the present time, however, the object in view has been only partly and
imperfectly attained, and the advantages attributed to the use of iron frames for
isolating the wrest plank, were all more or less illusory as the desired isolation was not
effected and in fact could not be attained for the following reasons:
It has hitherto been the custom in manufacturing pianos to affix or attach the
tuning pins or pegs into the wrest plank, which generally consists of a strong beech
plank of about 24 centimeters in width and 3 to 4 centimeters in thickness, this being
glued to the back wall of the framework.
Now it will be evident that no advantage can possibly be attained by isolating the
strings of an instrument from the framework. if the wrest plank, which is very
sensitive to the effects of dampness and the change of weather, is subsequently brougbi
in direct connection with the case or framework of the piano, which, as is well known,
is very liable to transfer the aforesaid drawbacks to the wrest planks.
The aforementioned constructions possess the further disadvantage, that when it is
desired or becomes necessary to remove the iron frame for purposes of repair etc.
the entire number of strings must first be detached or loosened from the tuning or

page_text: bitch pegs, this manipulation naturally, causes a great loss of time which repeats
itself when the strings are replaced, and besides this the said strings or wires are
subjected to unnecessary wear and tear.
The improvements introduced by the present invention are calculated to effectively
overcome all the disadvantages above set forth, the wrest planks not being constructed
so as to be attached to, or dependent. from, the framework or casing of the pianoforte,
but being made quite independent of the latter, and affixed to and held by the iron
frame only, which is also of novel construction.
Numerous experiments and trials carried out by me have shown that this arrange-
ment of the wrest planks, tuning and hitch pins and frame is better adapted to with-
stand the enormous strain or tension of the wires or strings and generally to
effectively meet all the requirements called for and which are indispensable in a first
class pianoforte or other similar musical instrument.
In the accompanying drawings, in which similar letters of reference indicate
corresponding parts, .
Fig. 1 is the front view of the frame R of a cross stringed pianoforte provided
with my improved wrest planks S, S¹ the wires or strings being only partly
represented.
Fig. 2 is a top view of the frame R.
Fig. 3 represents in natural size the upper part of the frame R seen from the bass
side of the piano.
Fig. 4 is a section on the lino A-B, in Fig. 1 through that part of the wrest plank
to which the bass wires or strings are attached.
Fig. 5 is a section on the line C-Din Fig. 1. of the wrest planks with wires or
strings for the treble notes, in natural size.
Figs. 6 to 12 represent the direction of the fibre in the several planks or
boards a, b, c and d, e, f, g, constituting the wrest planks S, S¹.
According to my said invention I considerably decrease the width of the wrest
plank, the part S being only 6 centimeters and the part S¹ only 8 centimeters wide,
so that therefore the said wrest plank is entirely isolated from any other wooden parts
of the piano and, in order to adapt the same to receive and rigidly hold the pins or
pegs w and to withstand the great tension or strain exerted thereon by the wires, as
well as to reduce its expansion and contraction to a minimum, I construct the same
of two, three or more planks or boards S, as, for instance, Fig. 4 of a, b, c and S¹,
Fig. 5 of d, e, f, g, which are so arranged that their fibres run in opposite direction to
each other, substantially as shown, whereupon said planks are placed in the accurately
formed frame R, and fixed to each other from both sides by means of glue or its
equivalent in such manner that it is a matter of impossibility for the same to be
shifted either one way or the other, this rigidity of fixture being augmented by the.
tapering shape of the planks.
Besides this, however, each one of the back planks or boards a, b or d, e, f, which
are pulled forward when the pegs w have been inserted and the wires fixed thereto,
will press against the supporting projection in R, said projection being caused by the
decreased size of the counter grain planks c or g.
The whole strain or tensional power, therefore, is concentrated on the iron frame,
and that part of said frame destined to receive the wrest planks must be accurately
constructed in accordance with the form or shape of the latter, that is, the same must
be tapered from both sides to a common centre so as to represent an inverse cone.
Having now particularly described the nature of my said invention, what I
claim is :-
1st. In pianofortes and other similar musical instruments, the method of fixing or
fastening the wrest planks S, S¹ to the iron frame R, substantially as set forth and
shown on the drawings.
2nd. In pianofortes and other similar musical instruments, constructing the wrest
plank, such as S, S¹ of 2, 3 or more planks or boards, which are so arranged that their
fibres run in opposite direction to each other, said planks or boards being tapered to

page_text: a common centre from both sides so that the entire iron frame, wrest planks and all
the strings can be readily and simultaneously removed from the case of the pianoforte,
substantially as set forth and shown on the drawings.
3rd. In pianofortes and other similar musical instruments, constructing the upper
and lower part of an iron frame, such as R, for receiving the wrest planks, such
as S, S¹ substantially as set forth and shown on the drawings.
FELL & WILDING,
1, Queen Victoria Street, London, E.C.,
Agents for the Applicant.
FELL & WILDING,
1, Queen Victoria Street, London, E.C.,
Agents for the Applicant.