IMPROVEMENTS IN PIANOS
Year: 1859

page_text: LETTERS PATENT to Charles Glassborow, of Girard Avenue, Philadelphia,
in the United States of America, Piano Manufacturer, for the Invention
of "IMPROVEMENTS IN PIANOS."
Sealed the 17th January 1860, and dated the 15th August 1859.
PROVISIONAL SPECIFICATION left by the said Charles Glassborow at
the Office of the Commissioners of Patents, with his Petition, on the
15th August 1859.
I, CHARLES GLASSBOROW, of Girard Avenue, Philadelphia, in the United
States of America, Piano Manufacturer, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN PIANOS," to be as follows, that is to
say :-
This Invention relates to an improvement in that class of pianos generally
termed upright or cabinet pianos, the strings of which are arranged either
perpendicularly or obliquely, in a vertical instead of a horizontal plane, as in
square or grand pianos.
The improvement consists in constructing the frame of a piano of this
class with two complete pin and bottom blocks, having suitable attachments
for receiving two distinct sets of strings and two complete sounding boards,
the latter being connected together at suitable intervals.
The objects of the Invention are, firstly, to equalize the strain on both sides

page_text: of the frame, so that the latter may be made much lighter than usual, and so
that the instrument may be maintained in tune longer than ordinary upright
pianos; secondly, to increase the volume of the tone by tuning the strings
on one side, to the same pitch as those on the opposite side of the frame, the
vibration imparted by the hammer to a string on one side being communicated
to the string of the same pitch on the opposite side; and, thirdly, to prevent
the sounding boards from sinking in the middle.
In tuning this instrument, it is necessary that the corresponding strings on
the opposite sides should be tuned to the same pitch, and inasmuch as the
corresponding strings are of similar material they must have exactly the same
tension imparted to them, consequently the strain on one side of the frame
will be exactly equal to that on the other. By this arrangement the massive
frame used in this class of instruments to the injury of the tone, as well as
the usual cumbrous braces may be dispensed with, and a frame composed of
light materials, and occupying but little space, may be substituted.
Another advantage gained by this arrangement is the facility with which
the sounding boards may be connected together, so that the pressure of the
strings on one board is neutralized by the pressure of the strings on the other
board, the tendency of the boards to sink in the middle and warp being thus
obviated.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Charles Glassborow in the Great Seal Patent Office on the
18th January 1860.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
GLASSBOROW, of Girard Avenue, Philadelphia, in the United States of America,
Piano Manufacturer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifteenth day of August, in the year of our Lord
One thousand eight hundred and fifty-nine, in the twenty-third year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Charles Glassborow, Her special license that I, the said
Charles Glassborow, my executors, administrators, and assigns, or such
others as I, the said Charles Glassborow, my executors, administrators, or
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

page_text: Great Britain and Ireland, the Channel Islands, and Isle of Man, an Inven-
tion for "IMPROVEMENTS IN PIANOS," upon the condition (amongst others).
that I, the said Charles Glassborow, by an instrument in writing under
my hand and seal, 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 Glassborow, 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, reference being had to the accompanying Drawings, and
to the letters and figures marked thereon, that is to say :-
My said Invention relates to an improvement in that class of pianos
generally termed upright or cabinet pianos, the strings of which are arranged
either perpendicularly or obliquely in a vertical instead of horizontal plane, as
in square or grand pianos.
The improvement consists in constructing the frame of a piano of this class
with two complete pin and bottom blocks, having suitable attachments for
receiving two distinct sets of strings and two complete sounding boards, the
latter being connected together at suitable intervals.
The objects of the Invention arc, firstly, to equalize the strain on both
sides of the frame, so that the latter may be made much lighter than usual,
and so that the instrument may be maintained in tune longer than ordinary
upright pianos; secondly, to increase the volume of the tone by tuning the
strings on one side to the same pitch as those on the opposite side of the
frame, the vibration imparted by the hammer to a string on one side being.
communicated to the string of the same pitch on the opposite side; and,
thirdly, to prevent the sounding boards from sinking in the middle.
And in order that my said Invention may be fully understood, I shall
now proceed more particularly to describe the same, and for that purpose I
shall refer to the several Figures on the Sheet of Drawings hereunto annexed,
the same letters of reference indicating corresponding parts throughout all the
Figures.
Figure 1 of the Drawings represents a front view of the improved string
frame of an upright piano; Figure 2 is a top view of the same; Figure 3 is a
sectional view of the frame; Figure 4 is an end view; and Figure 5, a
transverse sectional view of the frame.
•
A and A' are the two pin blocks of the frame, situated one on each side of,
and securely bolted to the end beams B and B and intermediate beams C
.

page_text: and C, the said pin blocks being directly opposite to and in a line with each
other; D and D₁ are the two bottom blocks of the frame secured, one to
each side of the end and intermediate beams; and E and E' are diagonal
beams secured to the bottom blocks D and D', end beam B', and intermediate
beam C. Each pin block is furnished with the requisite number of tuning
pins a, a, round each of which a string is coiled as usual, the lower end of
the strings being attached to pins driven into a cast iron plate F, one of which
is secured to each side of the frame. To each pin block is secured the usual
bridge piece b, over which the strings pass and on which they bear, the strings
being retained in their proper position on the bridge by suitable guide pins.
Between the pin blocks and bottom blocks are situated the sounding
boards G, G, one on each side of the frame, the boards resting on ledges
formed on the pin and bottom blocks, so as to be the requisite distance from
the strings. Each sounding board is provided with the usual bridge piece H,
the latter having pins to retain the strings in their proper position. The two
sounding boards are connected together by stay bolts e placed at suitable
intervals, the ends of the bolts passing through the boards, as well as through
the bridge pieces EI, and being securely fastened to both by suitable nuts.
It will now be seen, without further description, that there are two complete
sets of strings and two complete sounding boards on one frame, the strings
on one side being of similar material and of the same strength as those on
the opposite side.
In tuning the instrument, it is necessary that the corresponding strings on
the opposite side should be tuned to the same pitch, and inasmuch as the
corresponding strings are of similar material, they must have exactly the
same tension imparted to them, consequently the strain on one side of the
frame will be exactly equal to that on the other. By this arrangement, the
massive frame used in this class of instruments to the injury of the tone, as
well as the usual cumbrous braces, may be dispensed with, and a frame com-
posed of light materials, and occupying but little space, may be substituted.
The strain being equal on both sides, the instrument may be maintained in
tune much longer than when the strings, and consequently the strain, are on
one side of the frame only.
Another advantage gained by this arrangement, is the facility with which
the sounding boards may be connected together, so that the pressure of the
strings on one board is neutralized by the pressure of the strings on the other
board, the tendency of the boards to sink in the middle and warp being thus
obviated. In addition to the improvement in the tone gained by the substi-
tution of a light for a massive and heavy frame, the volume of the tone is

page_text: increased by the use of two sets of strings; for it will be evident that the
moment one of the strings on one side is sounded, the string of corresponding
pitch on the opposite side will give out a mellow and prolonged sound, which
will add to the volume and power of the instrument's tone.
Having now described and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be used or carried into
effect, I would observe, in conclusion, that what I consider to be novel and
original, and therefore claim as the Invention secured to me by the herein-
before in part recited Letters Patent, is,―
First, the general construction and arrangement of pianofortes, as herein-
before described.
Second, constructing the string frames of upright pianofortes with two
pin blocks and other appliances for receiving two sets of duplicate strings
disposed on both sides of the frame, as herein-before described.
In witness whereof, I, the said Charles Glassborow, have hereunto
set my hand and seal, this Nineteenth day of December, Onc
thousand eight hundred and fifty-nine.
Signed, sealed, and delivered
in presence of
HENRY HOWSON.
GEORGE CRUMP.
CHARLES GLASSBOROW. (L.S.)