Year: 1888

page_text: Date of Application, 19th May, 1888
Complete Specification Left, 3rd Jan., 1889
Compete Specification Accepted, 12th Feb., 1889
I, EDMUND BROOK NUNN, of Baldock Street, Royston, in the County of Hertford,
Gentleman, do hereby declare the nature of this invention to bo as follows:-
My invention relates to piano-fortes and other musical instruments baving strings
or wires and comprises improved means for producing the tension of the strings or
wires.
According to my said invention each string instead of being attached to a wrest
pin, is connected to one end of a lover, the other end of which is attached by a
connecting string, wire, or the like, to a wrest pin in such a manner that when the
said connecting string, wire, or the like, is tightened upon the said wrest pin, the
lever will be moved to correspondingly tighten the musical wire or string attached
to it.
The end of the lever to which the musical wire or string is connected is preferably
formed of segmental or cylindrical shape and rests in the groove of a bar; and the
other end of the said lever to which the connecting string or wire is attached is also
preferably of segmental shape, to afford a surface for the strings to bear against and
to maintain the length uniform.
The wrest pins to which the connecting strings or wires are attached are screw-
threaded, and before the attachment of the said connecting strings or wires are
screwed down into the plank or the like carrying them, so that as they are unscrewed
to tighten the wires or strings, the portions of the latter which are wound upon the
said pins will lay themselves in the threads thereof.
of May 1980
G. F. REDFERN & Co.,
4, South Street, Finsbury, London,
Agents for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements in Pianofortes and similar Stringed Instruments.
I, EDMUND BROOK NUNN, of Baldock Street, Royston, in the County of Hertford,
Gentleman, do hereby declare the nature of this invention and the manner in which
the same is to be performed to be particularly described and ascertained in and by
the following statement:—
My invention relates piano-fortes and other musical instruments having strings
or wires, and comprises improved means for producing the tension of such strings or
wires.
According to my said invention each string or wire instead of being attached to a
wrest pin, is connected to a lever, one end of which is attached by a connecting
string, wire, or the like, to a wrest pin in such a manner that when the said connecting
string, wire, or the like, is tightened upon the said wrest pin, the lever will be moved
to correspondingly tighten the musical wire or string attached to it.
In the accompanying drawing
Figure 1 is a vertical section of so much of a pianoforte as is necessary to show
the application of my invention thereto, and
Figure 2 is a front elevation of portions of the same.
Figures 3, 4, and 5 are a side elevation, end elevation, and top view respectively of
one of the levers detached.
Figures 6 and 7 are a plan, and front elevation of a bar or seat upon which the
levers rest, and
Figuro 8 is a transverse section of the same.
Figure 9. is a view illustrating a modified form of lever.
a, a indicate the wires of a piano-forte and b, 6 the levers to which the said wires
are connected. e is a bar or seat upon which the levers b, brest, and which extends
throughout the whole width of the piano-forte, the said seat being provided with a
number of upwardly extending arms or blocks d, d for a purpose hereinafter
described.
Each lever is formed with a boss or hub e which rests in the seat c, as shown in
figure 1, and with a hook or projection to which the wire is attached. The said
hook is located in a recess in the lever, so that the lever may be as thin as possible, as
in figure 5; this thinness being essential to allow a large number of levers to be
placed side by side (as shown in figure 2) in a little space. When a number of levers
are upon the seat c the arms d, d prevent them from falling over laterally. I
advantageously pass a bolt e¹ through the bosses of all the levers, which bolt assists in
maintaining the levers in place during the time that the instrument is being erected,
and also in case one of the wires or strings breaks, the said bolt prevents the lever
from falling out of position.-
A portion of the periphery of each boss is provided with a groove g which prevents
the wire from slipping off the boss after it has been placed in position.

page_text: The free end of each lever b is connected by a wire or string i to a wrest pin k
secured in the plank 1. The wrest pins are, preferably, screw-threaded, and before
the attachment of the wires or strings i, i are screwed down into the plank, as shown
in figure 1, so that as they are turned to tighten the wires a, a, the said pins will be
more or less withdrawn, whereby the wires i, i will lay themselves in the threads of
the pins.
The end of each lever is also provided with a groove m to prevent the wire or
string from slipping therefrom.
Instead of forming the boss of a circular shape, as hereinbefore described, I in
some cases make the boss in the form of a cam, as shown in figure 9 whereby as the
lever is moved, I not only obtain the tension of the wire or string due to the rotation
of the boss, but the additional tension due to the eccentric movement of the same.
I wish it understood that I do not limit my invention to the use of levers of the
shape shown, as it is obvious that the shape may be considerably modified. Neither
do I confine myself to the method of mounting the levers or to the means for drawing
up the same, as both of such may be modified.
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 1
claim is :-
(1) The improvement in piano-fortes and similar stringed instruments which consists
in attaching the strings or wires to levers so mounted that when the said levers are
moved in the proper direction the tension of the strings will be varied, substantially
in the manner, and for the purpose, set forth.
(2) In a piano-forte or similar instrument the employment of levers of the kind
shown in the drawing, one end of each of which has connected to it one of the wires
or strings of the instrument while the other end is connected to a wrest pin, sub-
stantially as described.
(3) The manufacture and use of pianofortes provided with the improvement herein-
before described and illustrated in the accompanying drawing.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London,
Agents for the Applicant.