IMPROVEMENTS IN PIANOFORTES
Year: 1871

page_text: LETTERS PATENT to Charles Frederick Chow, of Haverstock Hill, in
the County of Middlesex, for the Invention of "IMPROVEMENTS IN
PIANOFORTES."
Sealed the 28th November 1871, and dated the 1st June 1871.
PROVISIONAL SPECIFICATION left by the said Charles Frederick Chew
at the Office of the Commissioners of Patents, with his Petition, on
the 1st June 1871.
I, CHARLES FREDERICK CHEW, of Haverstock Hill, in the County of
Middlesex, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN PIANOFORTES," to be as follows :-
This Invention relates to certain improvements on a former Patent
granted to me, the said Charles Frederick Ohew, and bearing date the
26th day of May 1869, numbered 1619, for improvements in pianofortes,
and the present Invention consists in constructing certain parts of piano-
fortes in the following manner:―
First. In making the pins marked A in the Specification and Drawings
of the aforesaid former Patent conical instead of cylindrical and fitting

page_text: them into corresponding conical holes formed in the back of the piano-
forte. I also form the lower end of the said conical pin square or
hexagonal or other number of sides, over which said parts one of two
washers fits. Leather is also placed between the two washers, and a
screw is formed on the lower part of the pin fitted with a nut for
tightening the said pins in the back. By these means I obtain increased
friction, and at the same time enable the pins to be turned round or
partly round for tightening the strings of the pianoforte, and thus afford
greater facilities for tuning in consequence of the aforesaid tightening
nut moving round with the conical pin on which it is placed, instead of
the said nut having an independent movement as described in the Speci-
fication of the aforesaid former Patent.
Secondly. In the application of adjustable straps of metal to the back
or spine of a pianoforte, the said straps extending from top to bottom of
the back, and fixed thereto by their ends, and midway of the length of
each strap, and to the said back I connect a screw bolt, the head whereof
is intended to press against the aforesaid strap. I also form bosses on
those parts of the back that come opposite to each of the said straps.
Each boss has a hole made in it larger than the screwed part of the bolt,
so that the bolt may be loose therein. Now, suppose a screw nut to be
first placed on the bolt and rest against the said boss, by holding the
said nut with one hand and turning round the bolt by its head the said
bolt will be moved outwards and forcibly pressed against the strap, and
thus cause extreme tension thereof.
The third part of this Invention relates to a method for preventing
the bridges of pianofortes from "heeling over," especially in pianofortes
that are subjected to extreme tension. I propose to effect this object by
straps of wood or other material or wires fixed to the bridge by their
upper ends, and by their lower ends to the frame of the pianoforte, taking
care to so fix them that they are clear of the sound board.
The fourth part of this Invention consists in adapting a chamber to
the hinged top of a pianoforte, or in making the said top hollow and per-
forated at the top or bottom of such said chambers or at both such parts,
the use of such said hollow top or chamber being to reflect the sound.

page_text: filed by the said Charles Frederick Chew in the Great Seal Patent
Office on the 1st December 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
FREDERICK CHEW, of Haverstock Hill, in the County of Middlesex, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the First day of June, in the year of our
Lord One thousand eight hundred and seventy-one, in the thirty-fourth
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said Charles Frederick Chew, Her special licence that
I, the said Charles Frederick Chew, my executors, administrators, and
assigns, or such others as I, the said Charles Frederick Chew, my exe-
cutors, administrators, and assigns, should at any time agree with, and
no others, from time to time and at all times thereafter during the
term therein expressed, should and lawfully might make, use, exercise,
and vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
PIANOFORTES," upon the condition (amongst others) that I, the said Charles
Frederick Chew, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and seals, should
particularly describe and ascertain the nature of the said Invention,
and in what manner the same was to be performed, and cause the
same to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Charles Frederick Chew, do hereby
declare the nature of my said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement, that is to say :--
This Invention relates to certain improvements on a former Patent
granted to me the said Charles Frederick Chew, and bearing date the
26th day of May 1869, numbered 1619, for improvements in pianofortes,
and the present Invention consists in constructiong certain parts of
pianofortes in the following manner :-

page_text: First. In making the pins marked A in the Specification and Drawings
of the aforesaid former Patent conical instead of cylindrical and fitting
them into corresponding conical holes formed in the back of the
pianoforte. I also form the lower end of the said conical pin square or
hexagonal, or other number of sides over which said parts, one of two
washers fits, leather is also placed between the two washers, and a screw
is formed on the lower part of the pin fitted with a nut for tightening
the said pins in the back. By these means I obtain increased friction
and at the same time enable the pins to be turned round or partly
round for tightening the strings of the pianoforte, and thus afford 1
greater facilities for tuning, in consequence of the aforesaid tightening
nut moving round with the conical pin on which it is placed instead of
the said nut having an independant movement as described in the
Specification of the aforesaid former Patent.
Secondly. In the application of adjustable straps of metal to the back
or spine of a pianoforte, the said straps extending from top to bottom
of the back and fixed thereto by their ends and midway of the length
of each strap, and to the said back I connect a screw bolt, the head
whereof is intended to press against the aforesaid strap. also form
bosses on those parts of the back that come opposite to each of the
said straps; each boss has a hole made in it larger than the screwed part
of the bolt so that the bolt may be loose therein. Now suppose a screw
nut to be first placed on the bolt, and rest against the said boss, by
holding the said nut with one hand and turning round the bolt by its
head the said bolt will be moved outwards and forcibly pressed against
the strap, and thus cause extreme tension thereof.
The third part of this Invention relates to a method for preventing
the bridges of pianofortes from "heeling over," especially in pianofortes
that are subjected to extreme tension. I propose to effect this object by
straps of wood or other material or wires fixed to the bridge by their
upper ends, and by their lower ends to the frame of the pianoforte,
taking care to so fix them that they are clear of the sound board.
The fourth part of this Invention consists in adapting a chamber to
the hinged top of a pianoforte or in making the said top hollow, and
perforated at the top or bottom of such said chambers or at both such
parts, the use of such said hollow top or chamber being to reflect the
sound.

page_text: And in order to explain my said Invention more clearly I now
proceed to describe the means by which it may be carried into practical
effect, reference being had to the illustrative Sheet of Drawings
accompanying this Specification, and to the numeral figures and letters
of reference marked thereon respectively. as follows :-
:-
DESCRIPTION OF THE DRAWING.
Figure 1 represents a portion of the top part of the back or spine of an
upright pianoforte, shewing one of my improved pins applied thereto;
Figure 2 is an elevation of a portion of the bracing of a pianoforte,
shewing my improved method of adjusting or tightening the tension.
straps fixed to the back of the pianoforte; Figure 3 is a front elevation
of the back or spine of a pianoforte and the sound board and bridge,
shewing my improved method for preventing the bridge from "heeling
over"; Figure 4 shews the under side of the top or cover of an upright
pianoforte, constructed according to my said Invention to reflect the
sound; Figure 5 is a cross section through the line A, B, at Figure 4;
and Figure 6 shews the said top or cover without the bottom shew at
Figure 4. At each of the above Figures I employ similar letters of
reference to denote corresponding parts.
As regards Figure 1, A marks one of the pins of a pianoforte, to which
one end of the strings is fixed as commonly practised; B marks the
part of the back or spine that carries the said pins. The part a of the
pin A is made conical and fits into a corresponding shaped hole made
in the part B; 6 is a square formed on the pin A; and C is a metal
washer with a square hole therein which fits on the part b. The part c
of the pin A is formed cylindrical, and carries a leather washer d and
metal washer e with a round hole in each; D is a nut fitting on the
screwed part of the pin A. By this improved arrangement the nut D
moves with the pin A as it is turned round for tightening the string
fixed thereto in the act of tuning, and the nut D in combination with
the conical part of the pin and hole in which it rests (when the nut is
tightened against the back) prevents the string from slackening.
As regards Figure 2, E marks a portion of the ordinary bracing of
a pianoforte, and G is a portion of one of the tension straps, and the
improvement in this part of my said Invention consists in applying

page_text: a screw bolt H between the aforesaid tension strap and bracing. The
head of the bolt H presses against the strap G, and the screwed part
of the bolt passes loosely in a hole in the part E of the bracing, so that
as the nut I on the bolt H is screwed thereon, it will press the head
of the bolt forcibly against the strap G, and cause extreme tension
thereof, and this applies to all the straps shewn by dotted lines at
Figure 3, at which said Figure, K marks the metal back or spine of a
pianoforte L, the sounding board of the ordinary kind fixed to the back
by bolts at f, f; M is the ordinary bridge, and N are straps fixed by
one end to the bridge and by their opposite ends to the back or spine K
by bolts at g.
As regards Figures 4, 5, 6, O marks the top or cover of a pianoforte
which for the purposes of this Invention I form hollow as a box; P is
the bottom or under side thereof with openings h formed therein, for
the sound to pass through. These openings may be covered with silk
or other like material; Q are bars arranged as shewn. The lid or
cover thus constructed may be hinged to the instrument in the usual
way.
Having now fully described and set forth the nature and object of
my said Invention for improvements in pianofortes, together with the
best means I am acquanted with for carrying the same into practical
effect, I desire it to be distinctly understood that what I claim as my
Invention intended to be secured to me by the herein-before in part
recited Letters Patent is as follows:-

page_text: Fourthly. Making the tops of pianofortes hollow as a box, as
represented for the purpose of reflecting the sound.
In witness whereof, I, the said Charles Frederick Chew, have
hereunto set my hand and seal, this Thirtieth day of November,
in the year of our Lord One thousand eight hundred and seventy-
one.
C. F. CHEW. (L.S.)