Improvements in Pianos.
Year: 1894

page_text: Date of Application, 30th Jan., 1894-Accepted, 7th Apr., 1894
Improvements in Pianos.
We, LORENZ MATT and JOSEPH FRANCIS MATT, both of No. 75 Best Street,
in the City of Buffalo, County of Erie and State of New York, United States of
America, Piano Manufacturers, 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 :-
This invention relates to the sounding board of the piano and the bridge
supported thereon.
Heretofore sounding boards have been constructed of a single layer or thickness
and also of a number of thicknesses or veneers, but in order to permit such boards
to be made sufficiently thin, to obtain the desired resonance, it has been necessary
to reinforce them by stiffening bars or cleats extending across the same.
These
bars necessarily impair, in a measure, the vibrating capacity of the board and
correspondingly diminish its resonance.
One object of our invention is the production of a sounding board which shall be
sufficiently thin to insure the desired vibrating quality, and which shall at the same
time possess the necessary strength to resist the strains to which it is subjected,
without requiring stiffening bars or similar reinforcing parts which extend across
the board and restrain its vibrations.
Our invention has the further objects to relieve the sounding board from the
pressure of the bridge and thus give the same greater freedom of vibration, and to
improve the construction of the board in other respects, with a view of increasing
the volume of the sound and improving its quality.
In the accompanying drawings:-
Figure 1 is a front elevation of a portion of the sounding board of an upright
piano embodying our improvements.
Figure 2 is a cross section thereof on the line 2-2 of Figure 1.
Figure 3 is a longitudinal section of the same on the line 3-3 of Figure 1.
Figure 4 is a front elevation thereof, with the strings and the bearing bar of the
bridge omitted.
Figure 5 is a cross section of the bridge and the sounding board, on an enlarged
scale.
Figure 6 is a fragmentary front view of said parts.
Like letters of reference refer to like parts in the several figures.
A is the frame or case of the piano, which is of the usual rigid construction,
B represents the sounding board; C the bridge and D the strings.
The sounding board is composed of a number of veneers or thin layers of wood b,
which are glued together, one upon the other, and are so arranged that the grain
of one layer crosses the grain of the contiguous layer or layers about at right
angles, the grain of the first layer, or that nearest the strings, running crosswise of
the bridge. Four of such layers are preferably employed, and they are made so
thin that the thickest portion of the sounding board does not exceed one fourth of
an inch. The veneers or layers are cut in such a manner that the grain extends
through each layer at right angles to the plane of the contiguous layer or layers,
substantially as shown at 6', in Figures 2, 3, 4, and 5. By employing layers with
the grain running in this manner, the layers offer their greatest resisting power in
the most effective manner, which renders their strength so great as to permit the
use of a comparatively thin sounding board, without requiring any stiffening bars.
The board can therefore vibrate with much less restraint than a board having such
stiffening bars, and produces a sound of correspondingly greater volume.

page_text: The sounding board is made of gradually increasing width and thickness from
the portion thereof opposite the high or treble strings toward the portion thereof
opposite the lower or bass strings, as shown in Figure 3, the dimensions of the board
increasing in the same measure as the strings increase in length and thickness. By
thus proportioning the sounding board with reference to the size of the strings, the
power of the various tones is rendered more uniform and the bass and the treble of
the instrument are evenly balanced. We have obtained satisfactory results by
making the sounding board about three sixteenths of an inch in thickness opposite
the string producing the highest tone, and increasing its thickness one thirty-second
of an inch for each octave from the treble toward the bass.
E is a support against which the sounding board rests and which is in turn
supported in the main frame or case. This support consists of a thin open frame
of wood which bears against the marginal portions only of the sounding board, as
shown in Figure 2, and by dotted lines in Figures 1 and 4, so as to leave the central
portion of the board free to vibrate, while it supports the sounding board for a
certain distance inwardly from the inner edge of the main frame. The longi-
tudinal side members e of this support are made of gradually increasing width and
thickness from the treble toward the bass strings. Satisfactory results have been
obtained by constructing this support of the following dimensions.
The side members e of the support should be one inch wide opposite the highest
string and increase in width one half of an inch for each octave toward the bass and
should be one sixteenth of an inch thick opposite the highest string and increase in
thickness one thirty-second of an inch for each octave. The inner edges of these
side members should be one half of an inch from the adjacent longitudinal edges of
the bridge base, at a point opposite the highest string, and this distance should
gradually increase toward the bass strings at the rate of one fourth of an inch for
every octave. The inner edge of the upper member e' of the support should be
half an inch from the highest string and the corresponding edge of the lower
member e one inch from the lowest string. The grain of these upper and lower
members preferably runs at right angles to the grain of the contiguous layer of the
sounding board, while the grain of the side members of the support runs parallel
with the grain of said layer.
The bridge C is constructed of a number of layers or veneers c of spruce, or
similar soft wood, firmly glued together. These layers extend lengthwise of the
bridge, and stand at right angles to the plane of the sounding board. The layers
are preferably cut in such a manner that the grain extends through the same
parallel with the plane of the layers, as shown in Figure 4. The bridge is made of
gradually increasing dimensions from the treble toward the bass strings in accordance
with the increasing dimensions of the sounding board. A bridge of soft wood thus
constructed, while possessing the requisite strength, has been found to produce
more pleasing tone than a bridge constructed of maple or other hard wood.
a
The following dimensions for the bridge have been found satisfactory and are
preferably employed. Its base should be one inch wide opposite the highest string
and should gradually increase in width at the rate of one sixteenth of an inch for
each octave toward the bass. The height of the bridge may be about one inch and
one eighth and its ends should be about an inch and a half from the highest and lowest
strings, respectively.
f represents a bearing bar or rod of metal or any other hard substance which is
arranged upon the bridge and against which the strings bear. The strings are
attached at their ends to the usual pins g and are strung in two groups or series,
the strings of one series bearing against the front side of the bar f and the strings
of the other series against the rear side thereof, as clearly shown in Figure 2.
The
strings of the two series are preferably arranged to bear alternately against opposite
sides of the bar, as shown, and the points of attachment of the strings are sub-
stantially in line with the middle or axis of the bearing bar, so that the strings of
both series are deflected at about the same angle. The bearing bar is secured to
the top of the bridge by perforated cars, and the bridge is provided in its top with

page_text: notches or recesses h, as shown in Figure 3, for the passage of the rear or lower
strings.
By thus arranging the strings to impinge against opposite sides of the bearing on
the bridge, the opposing pressures of the two series of strings counteract each
other, so that the bridge and the sounding board are practically relieved from
pressure, thereby allowing the sounding board to vibrate with much greater freedom
and greatly increasing its resonance.
By the use of our improvements, the resonance of the entire sounding board is
not only materially increased, but the higher treble tones, which in ordinary
instruments are dull and unmusical, have a sweet, singing quality that renders them
as pleasing to the ear as the lower tones.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is:
1. A sounding board for pianos, made of increasing thickness from the treble
toward the bass strings of the instrument, in accordance with the increasing size of
the strings, substantially as set forth.
2. A sounding board for musical instruments, made of increasing width and
thickness from the treble toward the bass strings of the instrument, substantially
as set forth.
3. The combination with the main frame and a sounding board composed of a
number of layers, of a thin support extending inwardly beyond the main frame and
bearing only against the marginal portions of the sounding board, substantially as
set forth.
4. The combination with the main frame and a sounding board composed of a
number of layers, of an open supporting frame extending inwardly beyond the main
frame and composed of thin members bearing only against the marginal portions
of the sounding board, substantially as set forth.
5. The combination with a sounding board composed of a number of layers and
constructed of gradually increasing dimensions from the treble toward the bass
strings of the instrument, of an open supporting frame composed of thin layers
bearing only against the marginal portions of the sounding board, and made of
correspondingly increasing dimensions, substantially as set forth.
6. The combination with a sounding board made of gradually increasing
dimensions from the treble toward the bass strings of the instrument, of a bridge
made of correspondingly increasing dimensions, substantially as set forth.
7. The combination with the sounding board and the bridge resting thereon, of a
bearing bar arranged on top of the bridge, and strings arranged in two series,
impinging against the front and rear sides of said bar, respectively, substantially as
set forth.
7
T
1004
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicants.