in Pianos and other like Musical Instruments.
Year: 1886

page_text: in Pianos and other like Musical Instruments.
I GEORGE FREDERICK REDFERN, of the General Patent Office, No. 4, South
Street, Finsbury, in the County of Middlesex, Patent Agent, do hereby declare the
nature of this invention (a communication from abroad by Alphonse Theyskens, of
18, Rue du Progrès, Brussels, in the Kingdom of Belgium, Engineer) and in what
manner the same is to be performed, to be particularly described and ascertaineḍ
in and by the following statement :-
This invention relates to the construction of an improved apparatus for stretching
metallic or other strings in pianos and other like musical instruments.
In order to enable the invention to be fully understood I will describe the same
by reference to the accompanying drawings in which figures 1, 2 and 3, are
transverse sections of apparatus for stretching metallic or other strings constructed
according to my invention the same being shewn fixed to the sound board of a
piano or the like; figure 4 is a longitudinal section on line D B of figure 2 and
figure 5 is a plan of the same; figure 6 is a cross section and figure 7 a longitudinal
section of the screw bolt to which the string is attached, the latter view illustrating
the method of such attachment, and also shewing a portion of the key for operating
the said bolt; figure 8 is a sectional plan of figure 7; figure 9, is a cross section on
line EF of figure 7; figure 11 is a plan of the underside of figure 7 further
illustrating the method of attaching the string; figure 13 is an end view of
figure 11 figure 14 is a longitudinal section of part of the bolt shewing the
method of fixing a string thereto; figures 15 and 16 are longitudinal elevations
of the key, the latter figure shewing the key applied to the head of the bolt;
figures 17 and 18 are cross sections on lines G H and I J respectively of figure 16.
The apparatus is constructed of a frame A B C of cast iron, copper or other
suitable metal as shewn in figures 1, 2 and 3, which frame can be made in one or
several parts. A plate A C figures 1, 2 and 3 of steel or other suitable metal of
the shape of an arc of a circle the radii of which converge at the bottom of the
apparatus at B as shewn, connect the two ends A and C of the frame A B C so as
TD

page_text: to form a tube of the shape in cross-section of a truncated sector. The part A B
of this tube may be formed by the frame of the piano whether the same be of
wood, as shewn in figure 1, or of metal as shewn in figures 2 and 3. Sometimes
the part A B C may be formed in one single piece and be screwed and bolted
against the frame, properly so called, of the piano, or the said part A B C may be
integral with the frame of the piano.
The lower part L M of the apparatus is, as shewn in figure 4, provided with a
number of holes which allow of the passage of the strings arranged in a line I K
figure 5 which determines the position of each string.
The said holes are placed at certain distances from one another longitudinally as
shewn in figure 4 which distances will be those which should exist between the
strings as shown at A B C D E F. In this manner the proper position of the
strings and the respective distances between the strings, or in other words, the
exact position of each string is insured by means of the part L M figure 4 of
the apparatus.
The upper plate AC figures 1, 2 and 3 is also formed with holes of a peculiar
form which are for the purpose of receiving bolts hereinafter described. The said
holes are placed so that the radius passing through the axes of the holes at the
greatest possible distances from one another will also pass through the axes of the
holes A B C D E F of figure 4 (see figure 5). The apparatus can then serve as a
nut similar to that of a violin as shewn in figure 3 or as a counter nut as shewn in
figures 1 and 2. A bolt or pin shewn in figures 7, 8, 11 and 14 is provided, the
said bolt or pin being represented with its string in figures 11 and 14; it consists,
as regards its lower part, of a simple screw threaded rod flattened on one or both
of its faces or having a groove and of a form in transverse section which will allow
the nut to pass without friction against the latter. The form of this bolt should
also allow of it engaging, when provided with its string in a hole in the plate A C
figures 1, 2, 3 and in such a manner that it cannot turn therein. This result is
'obtained by making the transverse section of the bolt provided with its string of
other than circular shape, the interior edges of the holes having a like form. The
upper part of the bolt or pin is shown provided with its string in figures 7, 11, 13
and 14, and without its string in figure 8. This part is formed at S (figures 7
and 8) with a portion of circular section (or it can have the same section as the
lower part B of the bolt) and is in any case screw threaded like the lower part of
the bolt. This part forms the base of the neck L, the radius of which is equal to
or less than the interior radius of the nut minus the diameter of the string. The
neck L is terminated by a head T the diameter of which is equal to or smaller
than the interior diameter of the nut so as to allow of the latter passing above it.
The head T is formed with a slot or recess on one side and on the top, figures 7, 8,
11, 13 and 14, the slot serving to receive the end of the string; it is also flattened
laterally on the side opposite the lateral slot and is of a depth equal to the upper
slot figures 7, 8, 11, 13 and 14. The string passes through the hole A of the bolt
figure 7, the continuation passing into a groove up to the point C; thence it passes
through a hole formed through the axis of the screw as shewn in figure 7 and
leaves at D at the commencement of the neck L. The string, figure 7, is wound
round the neck L until the coils resting one against the other, fill the neck or
space between the body of the bolt S and the head T figure 11; the string is then
passed into the lateral slot of the head T and then into the upper slot figure 14,
where it is made into the form of a hook figure 13 and is cut off at the edge of the
head T in order to allow the nut to pass freely over it.
For placing the string in the apparatus an instrument or key is used, represented
partially in figures 7, 8 and 9; figures 15 and 16 are general views, and figures 17
and 18 are sections of the same. This key is constructed of a piece of steel A B
figures 15 and 16, the lower part B of which is screw-threaded for a distance equal
to the length of the neck L of the bolt figures 7 and 8; the remainder of the
part E G figure 7 is cylindrical and has a diameter equal to that of the head T of
the bolt. This cylindrical part has three slots, figure 9, the first of which slots D

page_text: allows of the passage of the string during its provisional tension and winding
(figure 7), a piece of steel I figure 16 is attached to a slide M and can extend down
into this slot and as the slide M is movably attached to the rod N which has at its
upper part a screw thread corresponding to the screw thread on the part A, the
piece M can be caused to enter the slot D by forcing the string to fold back upon
itself towards the bottom and to occupy a position perpendicular to the axis of the
bolt. The said piece I can be easily removed. The second slot E figure 9 has a
lateral knife edge throughout its height which allows the thin strings to be folded
back over the flat face of the head of the bolt and serves to cut them at the
circumference of the head of the bolt figure 13 as hereinafter described. The
slot F figure 9 may contain a vertical knife K attached to the slide M figures 7
and 16 and serves to cut in a downward direction, the thick strings at the outer
circumference of the head of the bolt and on the flat surface formed on the head of
the latter. This cutting operation is effected by causing the knife K to descend by
means of the threaded part.
The apparatus is specially adapted for stretching the strings of pianos against
the sound board or at the place occupied by the same or if the apparatus be applied
against the piano it will then serve as a counter nut as shewn in Figure 1, without
inclining it towards the back or by so inclining it as shewn in figure 3.
The apparatus can be divided into as many sections as may be desired and follow
in a broken line the inclination of the nut without quite taking the curve thereof
and come back with it as shewn in figures 1 and 2.
Sometimes the string will only bear in the manner shewn at B figure 3 and in
this case the apparatus will itself form the nut and the part L M figure 4 should
completely follow the curve of the nut and take the place thereof. Besides this
inclination illustrated in figures 1, 2 and 3 the string can also be arranged in
different oblique directions as shewn in figure 4, so as to form upright, oblique or
other pianos without any special arrangement of the apparatus and without
requiring any hook, pin or other guide for the string. The apparatus being placed
in position and the lower holes A B C D E F figure 4 occupying their proper
position the lower end of the string is attached by passing it over the bridge and
over the nut and its free end is introduced into one of the lower holes B figures 1;
2 and 3 intended to receive it and then passed through the corresponding hole in
the plate A C; after having screwed the bolt into the key, as shewn in figure 7,
the string is placed in the hole A then through the hole Cits end passing out
through the slot D of the key. The free end of the string is then drawn tight by
sliding the bolt so as to cause it to enter the hole in the plate A C for receiving it
until the lower part of the key E C figure 7 rests on the plate A C figures 1, 2
and 3. The slide M figure 16 is then lowered, and by means of the screw O, the
piece of steel I is caused to enter the slot D figure 9 until the free end of the string
is alinost perpendicular to the axis of the bolt the end of the string is then again
drawn tight so as to stretch it to the required extent and the key is turned so as to
cause the string to wind on the bolt. The string drawn along by this movement
will be wound upon the neck L figure 14 as shewn in figure 9 and the coils will be
produced one after the other in proportion as the key is wound. When the coils
occupy the whole of the neck or the part L between the body of the bolt and the
head T the winding operation should be stopped the moment the slot D of the key,
figure 9, corresponds with the lateral slot M' of the bolt, figures 7, 8, 13 and 14.
The free end of the string is then placed in the said lateral slot M' of the bolt and
in the slot N' in the top of the bolt and by then turning it down and turning the
key in the same direction, the string will pass into the slot E of the key; as soon
as the string has become engaged in the latter slot the key should be turned in the
opposite direction when it will force the string to be bent back on to the flat part o
of the bolt and by continuing to turn the key the knife edge H figures 9 and 13. will
cut the string at the end of the diameter of the head of the bolt. If the string is
too thick to be cut by means of this knife edge, or if by reason of its thickness any
difficulty should be experienced in causing it to enter the top slot N¹ figures 7, 8,

page_text: 13 and 14 it should be placed in the slot F of the key figure 9 and by then lowering
the knife K of the key, figures 7 and 16, by means of the screw O figure 16 it will
be forced to descend and by giving a turn with the key in an opposite direction to
that hereinbefore described, the string will be folded against the flat part of the
bolt figure 13; then by causing the knife K. figure 16 to again descend by means
of the screw the string will be cut vertically at the end of the diameter at the
head of the bolt; it is only necessary then to remove the key and replace it by a
nut a figure
to give the string the required tension..
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is :-
1. The improved apparatus for stretching metallic strings in pianos and like
musical instruments hereinbefore described and represented in the accompanying
drawings.
2. In apparatus for stretching metallic strings of the kind herein referred to,
the employment of a tube of the form of a sector in cross section substantially
as set forth.
3. The thin plate which forms the arc of a circle of the sector provided with a
number of holes formed by a punch or in any other suitable manner substantially
as and for the purposes described and shewn in the accompanying drawings.
4. The employment of the herein described apparatus in pianos either as a nut
or counter nut substantially as set forth.
5. The combination of the herein described apparatus with tension bolts sub-
stantially as and for the purpose hereinbefore described.
6. The combination of parts forming the improved bolt substantially as set forth.
7. The arrangement and form of the herein described bolt for the purpose of
allowing a string to be attached thereto and of giving the latter the necessary
tension substantially as and for the purpose set forth.
8. The herein described means for allowing the string to be stretched before
fixing it to the bolt and the means for attaching the said string to the bolt
substantially as set forth.
9. The combination of parts forming the improved key substantially as herein-
before described.
10. In a key to be employed for the purpose herein described, the arrangement
whereby the string can be stretched and wound substantially as set forth.
1000
G. F. REDFERN.