Improvements in Sounding Boards for Upright and Horizontal Pianofortes.
Year: 1897

page_text: Date of Application, 19th Jan., 1897
Bomplete Specification Left, 18th Oct., 1897-Accepted, 20th Nov., 1897
PROVISIONAL SPECIFICATION.
Improvements in Sounding Boards for Upright and Horizontal
Pianofortes.
I, JOHN JOSEPH DEACOCK, Pianoforte Maker and Tuner of 17 Navarino Road
Hackney, N.E., in the County of Middlesex, do hereby declare the nature of this
invention to be as follows:-
My Invention has for its object, Firstly, Improvements in the means or arrangement
for fixing Sound board so as to avoid the "down-bearing" or stress, or pressure of
the strings or wires on such a portion or part of the sound board which carries the
treble wires.
Secondly:-Improvements in the shaping of the curvature or bellying that portion
of the sound board which carries the tenor and bass bridges. By these improvements
I am enabled to get greater power, purity and durability of tone.
My first improvement consists in fixing the sound board by glueing and screwing
such selected part or parts of the said sound board very firmly to the wood frame and
bracings of instrument, leaving other selected part or parts entirely free, or nearly so,
from any connection with the frame and bracings of the instrument other than the
wires or strings, which wires or strings are made to pull straight from the top bridge
to the hitch pin or bearing of frame, without giving any "down bearing" or
stress upon the sound board when the wires or strings pass and clip round the bridge
pins.
My second improvement consists in shaping or forming the curvature of sound
board. The ends of the strengthening bars which are fixed at the back of the said
sound board, are bevelled to a fine edge to meet the edge of the sound board; the
spaces between the ends of the said bars are filled with short blocks of wood, about
three inches, which also are bevelled to the same bevel as the bars; when this is
done the sound board is fitted upon the wood frame and bracings and I use the said
bevel given to the bars and blocks to spring or curve the sound board with certainty
upon the said wood frame and bracings of the instrument, either by clamping, or by
glueing, or by screwing the said bevel so formed, which was first out of the plane of
the wood frame or bracings, to become in the same plane with the said frame and
bracings.
In some cases I do not bevel the ends of the bars, I form the bevel upon the wood
frame or bracings and spring the sound board with its bars to the bevel formed on
frame or bracings.

page_text: Improvements in Sounding Boards for Upright and Horizontal
Pianofortes.
I, JOHN JOSEPH DEACOCK, of 17 Navarino Road, Dalston, in the County of
Middlesex, do hereby declare the nature of this invention and in what manner the
same is to be performed to be particularly described and ascertained in and by the
following statement :—
According to this invention in place of as heretofore for the most part usual
securing the sound board all around its edges to the frame I leave the treble end of
the board free preferably for about two and a half octaves. A block or washer of
metal, or of wood, cork, rubber, baize, felt, leather, or other suitable material may
however if desired be interposed between the free end and the frame.
Also at the same time that I leave the treble end of the sound board free I mount
the strings or wires in such a way as to pull straight from the top bridge to the hitch
pins or bearing of frame and so avoid down bearing or stress upon the sound board
where the strings or wires pass and clip round its bridge pins.
In a modification of the above instead of leaving the treble end of the sound board
entirely free I leave it as above described unattached to the frame around its edges
but attach to the central part of it bars which extend beyond its edges and attach
the ends of these bars to the frame so that by diminishing or increasing the thickness
or the length of these bars I can secure the amount of elasticity desired.
The sound board at the bass end I bring to a curved form. Various ways of
effecting this have before been proposed.
In my arrangement the ends of the strengthening bars which are fixed to the back
of the board are at their ends bevilled to a fine edge to meet the edge of the board
the spaces between the ends of the said bars are filled with short blocks of wood about
3 inches long which also are bevilled to the same bevil as the bars and I bring the
bevilled surface of the blocks and bars into close contact with and rigidly secure it to
the surface of the frame either by glueing or clamping or screwing or otherwise.
In this way the sound board is sprung or curved with certainty to the desired
extent.
In some cases I do not bevil the ends of the bars but form the bevil upon the wood
frame or bracings and spring the sound board with its bars to the bevil formed
on the frame or bracings.
Figure 1 is a front elevation showing the sound board fixed to the wood frame.
Figure 2 is a rear elevation of the sound board.
Figure 3 is a section through line 1-1.
Figure 4 is a section through line 2-2.
Figure 5 is a section of the sound board and one of the strengthening bars near
the bass end before it is sprung and secured to the frame.
Figure 6 is a section of sound board along line 3-3.
Figures 7 are sections of two forms of spring bars which in some cases I attach
to the treble end of the sound board.
Figure 8 is a section of a similar bar attached to the sound board and means of
securing the ends of the bar to framing.
Figure 9 is a rear elevation of treble portion of sound board showing similar
bars attached to the sound board in addition to the ordinary bars.
In these figures A is the sound board secured to the frame along the portion of
its edge marked C C C C C-the edge of the treble end of the board being left
unsecured to and out of contact with the frame. Usually I thus leave the treble end
of the sound board free as far as two and a half octaves but advantage may still
be obtained by only leaving it free as far as one octave.

page_text: B is a small block or washer of wood metal cork leather or other suitable
material which may if desired be interposed between the end corner of the board
and the frame. DD are bars which in some cases I attach to the treble end of the
sound board and make to extend beyond it as shown at Figures 8 and 9. E are screws by
which the ends of these bars may be secured to the frame. b is a strip of wood
glued to extreme edge of treble end of the sound board. F in Figure 3 is one of the
strings. G is the sound board bridge. H is the iron frame across which the strings
are stretched. K are strengthening bars bevilled off at their ends and attached to
the back of the bass and tenor end of the sound board. L are bevilled blocks placed
between the bevilled edges of the bars K. The bevilled surfaces of these blocks
and bars are as above stated to be glued or otherwise secured to the surface of
the frame.
In some cases in place of terminating the sound board along the top of the part J
of the framing as shown at Figures 1 and 2 and as is for the most part usual I
carry up the bass corner of the sound board square as indicated by the dotted lines M
in these figures. I then place a layer of felt baize or like suitable material over the
part J of the frame to come between it and the sound board-the strengthening
bars K I make as above described with bevilled ends and secure the bevilled surfaces
of these bars to the frame as above explained.
The improvements hereinbefore described relating to the treble end of the sound
board need not necessarily be used in conjunction with those described with reference
to the bass end, either can be used independently one of the other.
I would also state that I am aware that has before been proposed to have the
sound board completely free but so far as I am aware it is new to leave the three
side edges of the treble end of the sound board free whilst the remaining side
edges of the sound board around the bass and tenor end are fixed securely to the
frame.
said
Having now particularly described and ascertained the nature of my
invention and in what manner the same is to be performed 1 declare that what I
claim is
1. A sound board secured to the frame around its edges except at the treble end
which is left free substantially as described.
2. The modification in which the treble end of the sound board is left unsecured
to the frame around its edges and has bars attached to its centre and extending
beyond its edges which are at their ends secured to the frame.
3. Rounding or "bellying" the bass end of the sound board by bevilling off the
ends of its strengthening bars and blocks filling the spaces between these ends and
bringing the bevilled surfaces into close contact with and rigidly securing them to
the surface of the frame or forming the bevil on the frame instead of on the bars and
blocks.