IMPROVEMENTS IN THE CONSTRUCTION OF PIANOFORTES
Year: 1877

page_text: LETTERS PATENT to François Christophe Tessereau, of Paris, in the Republic
of France, for the Invention of "IMPROVEMENTS IN THE CONSTRUCTION OF
PIANOFORTES.”
Sealed the 13th October 1877, and dated the 7th August 1877. .
PROVISIONAL SPECIFICATION left by the said François Christophe Tesse-
reau at the Office of the Commissioners of Patents on the 7th August-1877.
FRANÇOIS CHRISTOPHE, TESSEREAU, of Paris, in the Republic of France. 'IM-
PROVEMENTS IN THE CONSTRUCTION OF PIANOFORTES."
"
This Invention comprises two distinct improvements, one of which has for its
object the construction of the instrument in such a manner that it may be taken
to pieces for the convenience of packing and the facility of transport in districts
where wheeled carriages are not available.
The second improvement has for its object to improve the tone by increasing the
sonority of the instrument.
These two improvements are, however, combined in the same instrument, although
they may be used separately.
The first improvement consists in constructing the framing, sounding board, wrest
plank, and other parts connected with the stringed part of the instrument, in two
sections, which are connected together (when the instrument is in use) by means
of sockets and dowels or pins, which are held in place by metallic tie rods or
analogous devices, so that when the parts are in place the strength or rigidity
of the instrument, and the quality. of tone and volume of sound are in no way
impaired.
all
This improvement is applicable to upright, horizontal, or oblique pianos, and the
division of the sections is made in a line parallel with the strings. The lower beam
of the wooden framing is provided with trusses or brackets to prevent the lateral
warping or yielding of the wrest plank or cross pieces, and give additional strength
to the instrument. By thus dividing the framing and sounding board with their
accessories into two parts, the whole instrument may be packed into four cases
ID 1

page_text: weighing about 140lbs. each, a weight that may be easily carried even on the backs
of mules.
The second improvement consists in adapting to the interior of the framing which
carries the sounding board and strings, metal tubes, as stretchers, or supports, in place
of the heavy solid wooden uprights usually employed. By the use of these tubular
_metal struts a greater free space is left beneath the sounding board, so that the
volume of sound will be increased. The space for the free vibration of the air is
still further increased by making openings in the metal tubes so as to allow the air
to pass into the interior. The wooden cross beams of the framing are provided
with square iron pieces carrying circular blocks or studs, which fit into the ends of
the metal tubes and hold the parts in place when all the parts are tightly screwed
up. Behind each of these tubes is placed a long tension bolt, which will counteract
the strain of the strings on the cross beams above.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said François. Christophe Tessereau in the Great Seal Patent Office on
the 7th February 1878.
..
FRANÇOIS CHRISTOPHE TESSEREAU, of Paris, in the Republic of France.
"IMPROVEMENTS IN THE CONSTRUCTION OF PIANOFORTES."
This Invention comprises two distinct improvements, one of which has for its
object the construction of the instrument in such a manner that it may be taken to
pieces for the convenience of packing and the facility of transport in districts where
wheeled carriages are not available.
The second improvement has for its object to improve the tone by increasing the
sonority of the instrument.
These two improvements are, however, combined in the same instrument, although
they may be used separately if desired.
The first improvement consists in constructing the framing, sounding board, wrest
plank, and other parts connected with the stringed part of the instrument, in two
sections, which are connected together (when the instrument is in use) by means of
sockets and dowels or pins, which are held in place by metallic tie rods or analogous
devices, so that when all the parts are in place the strength or rigidity of the
instrument and the quality of tone and volume of sound are in no way impaired.
This improvement is applicable to upright, horizontal, or oblique pianos, and the
division of the sections is made in a line parallel with the strings. The lower beam
of the wooden framing is provided with trusses or brackets to prevent the lateral
warping or yielding of the wrest plank or cross pieces, and give additional strength
to the instrument. By thus dividing the framing and sounding board, with their
accessories, into two parts, the whole instrument when divided may be packed into
four cases weighing about one hundred and forty pounds each, a weight that may be
easily carried even on the backs of mules.
The second improvement consists in adapting to the interior of the framing which
carries the sounding board and strings, metal tubes or stretchers or supports, in place
of the heavy solid wooden uprights usually employed. By the use of these tubular
metal struts, a greater free space is left beneath the sounding board, so that the
volume of sound will be increased. The space for the free vibration of the air is

page_text: still further increased by making openings in the metal tubes so as to allow the air.
to pass into the interior of the tubes. The wooden cross beams of the framing are
provided with square iron pieces carrying circular blocks or studs, which fit into the
ends of the metal tubes and hold the parts in place when all the parts are tightly
screwed up. Behind each of these tubes is placed a long tension bolt, which will
counteract the strain of the strings on the cross beams above.
The substitution of metal tubes for wooden uprights has the advantage of greatly
increasing the volume of tone or power. of the instrument, it also imparts great
strength and rigidity to the framing, and there is no danger to be apprehended from
the action of damp, heat, or insects. Moreover, instruments constructed in this
manner remain better in tune than when made with wooden upright bars.
In the accompanying Drawing Fig. 1 is an internal elevation of a piano, showing
the parts which constitute the framing and the, sounding board; divided into two
portions.
Fig. 2 is an internal elevation of the sides of the piano.
Fig. 3 is a transverse section of the piano showing the mode of attaching the iron
wrest plank.
Fig. 4 is an elevation showing the two parts of the sounding board, and the heavy
wooden framing to which it is secured.
Fig. 5 is an edge view.
Fig. 6 is a plan or top view; and Fig. 7, a sectional plan view showing the two
parts of the piano.
Fig. 8 is a section (drawn on an enlarged scale) of the parts of the sounding board
and wooden framing, which, when brought into contact, are connected together in the
manner hereafter explained.
Figs. 9 represent the iron fittings, whereby the wooden sides of the piano are
secured to the framing of the instrument.
Fig. 10 represents another iron fitting, which may be employed for the same
purpose.
Fig. 11 represents the iron fitting employed for securing together the two parts of
the wooden framing and the sounding board.
Fig. 12 is an elevation representing the tubular metallic stretchers adapted to the
framing in place of the ordinary heavy upright wooden bars.
Fig. 13 is a sectional plan view of the same.
Fig. 14 is a vertical section of the framing.
Fig. 15 is an elevation showing the position the metal tubes would occupy in the
framing if the Invention were applied to a piano in which the strings are placed
obliquely.
In Fig. 4 A, A, is the central post of the frame, divided down the middle to form
the joint of the two parts of the instrument, the other uprights of the framing being
shewn at a, a, a. The two parts of the frame are secured together when in place
by means of clamping screws B, B, Figures 1 and 6, and shown on an enlarged-scale
at Fig. 11. Steadying pins or metal tenons C on one half of the frame are made to
enter corresponding holes D, D, in the other half of the frame. The sounding
board E is provided at its central joint with wooden strips e, e, which form a
vertical groove to receive the projecting edge of the other half of the sounding board
when the parts are in place. G is the bridge; H, the wrest plank for the pegs
for the strings, and I the bridge or rest for the bent pins. J is a curved iron wrest
plank for receiving the points of the pins. K is the ordinary wrest plank made
in iron.
L, L, are the sides of the piano, and la plate provided with a screw ', and serving
to secure together the two parts of the heavy framing of the piano, which are
tightened up by means of the thumb nut 12, Fig. 9. Steadying pins M serve to
prevent all play between the framing and the sides of the piano.
N, Fig. 10, is an iron plate with a hole at its centre tapped to receive a screw N¹;
whereby the sides of the piano may be secured to the heavy framing.
In Figures 3 and 4 0, 0, are brackets or projecting trusses placed at the lower part

page_text: of the framing for the purpose of preventing the metal wrest plank K from being
strained or twisted.
In Figures 12, 13, and 14 P, P, are metallic tubes serving as stretchers or supports
for the heavy framing instead of the wooden posts a, a, Fig. 4, and have openings
p, p, made therein to allow the sound to enter. Q is a metal plate secured to the
cross piece of the framing, and J is a wooden wrest plank, to the edge of which the
sounding board is secured; it is provided with a metal plate J extending down to
the lower cross piece T¹.
Tension bolts S, S³, Fig. 14, extend from the upper cross piece T to the lower
one T¹, and serve to resist the tension of the strings.
It will be seen on referring to the Drawing, Figures 1 to 11, that the heavy
framing is arranged in the usual manner, and consists of strong heavy uprights
secured by their upper and lower ends to horizontal cross pieces. The framing at
its lower part carries the wooden wrest plank, which in the improved instrument is
provided with an iron plate which is prolonged (to increase the strength of the parts)
along the whole upper surface of the wooden wrest plank for the purpose of
receiving the pins. This heavy framing is cut down vertically through the middle
of the central post A, which is made of hard wood so as to possess sufficient rigidity
and solidity to receive the metal fittings whereby the parts are secured together.
These fittings consist of two sets of clamping screws, bolts, and nuts B and B', one of
which is placed at the upper part and the other at the lower part of the instrument.
Two double corner pieces b, 61, Figures 1 and 11, are countersunk in the cross pieces
T, T¹, and in one of the outer sides is made a hole, which is tapped to receive the end
of the clamping or tightening screw B. Independently of this mode of attachment,
and in order more accurately to bring the two parts of the framing into connection,
one of the posts A is provided with three tenons C, which enter sockets made in the
plates D fixed upon the other post A, so that when the screws B are tightened up
no motion of either of the parts on the other can take place; the double framing
will therefore be as strong and rigid as if it were made in one piece.
The sounding board E, being also in two pieces, is secured in the usual manner
upon the framing, and one of the parts carries two slips which form a groove and
cover the joint, and into this groove is inserted the edge of the other part of the
sounding board. If these parts are carefully and properly made.and lined with a
piece of cloth or felt, the two parts of the sounding board will be found to be per-
fectly solid and strong, and all disagreeable vibration will be completely prevented.
When the sounding board is made and arranged in this manner it will be found to
possess the same qualities as if it were made in one piece, and the sound or tone of
the piano will be exactly the same as that of ordinary pianos. Upon the lower
part of the sounding board thus constructed is placed in the usual manner a bolster
or bridge piece G, or two pieces abutting end to end, so that the covering slips
of the joint will be cut across at the point where the bridge passes them. Upon
the upper pin plank H are fastened the pieces I, I, which serve to receive the pins.
With the object of increasing the rigidity of the structure a metal plate j is
secured on the upper side of the curved part of the wrest plank J. This is
connected with the ordinary iron wrest plank K, and is intended to receive
the pins.
Figures 2 to 7 in the Drawings represent the sides L, L, of the piano as fixed to
the heavy framing a, a, by two strong screws and plates, shewn detached at Fig. 9.
These fittings are composed of a plate 7 secured to the wooden uprights by four
screws, one at each corner, and at the centre of the plate is rivetted a screwed piu l'
furnished with a wing nut. Upon the inner side of the side pieces of the piano are
fixed with ordinary wood screws two plates, and the rods of the plates 7 pass through
the end upright and are screwed up by the wing nuts. Steadying pins M take
into corresponding holes in the other parts and prevent any lateral shifting of the
parts.
The dismounting of the sides of the instrument greatly facilitates the packing
of the nexto

page_text: Figures 3 and 4 represent an improvement which consists in fixing firmly, (by
means of screws,) to the lower part of the uprights a, a, metal brackets O, O, against
the ends of which bear the upper edge of the iron wrest plank K, to which the bass
strings are secured. In this manner, notwithstanding the heavy pull or tension of
these strings, any twisting or yielding of the wrest plank K is rendered impossible
by the bracket O, for which holes are cut or made in the sounding board.
As regards the use of metal tubes in place of solid wooden bars for the uprights
of the framing, these tubes have openings p and p' made in them at each end for the
entrance and exit of the air, and their extreme ends fit over projecting metal studs
or blocks rivetted or screwed into the metal plate or fitting Q fixed on the cross
piece T and T. This framing is provided as usual at its upper part with a crooked
bridge piece, which is fixed thereon by means of screws or bolts. The lower part of
the metal tubes carries the ordinary wooden wrest plank J made with an edge j¹ to
receive the sounding board E. The iron wrest plank K always occupies the same
place.
The wooden wrest plank j is fixed by its ends upon the cross pieces of the
framing, also by screws passed through the tubes, as shewn at Fig. 14, so as to
consolidate and strengthen the whole structure. Moreover, at those parts of the
framing which are not covered by the sounding board there are arranged iron
fittings R which connect the wrest plank J to the lower cross piece T, under which
they are bent at right angles in order to receive the head of the first bolt S of the
tension arrangement S¹. The second bolt S2 passes on to the upper cross piece T.
The function of the tension arrangement S¹ is to equalize or counteract the tension
produced by the strings of the piano, and to prevent the twisting and strain of the
parts which might otherwise be produced. This kind of framing with metal tubes
may also be applied with advantage to horizontal and grand pianos, and either
cylindrical, oval, or other tubes may be used, as may be found most convenient, the
object always being to increase the tone and the sonority of the sounding board,
and contribute to the lightness and strength of the framing.
Having now described my Invention of "Improvements in the Construction of
Pianofortes," and having explained the manner of carrying the same into effect, I
claim as the Invention secured to me by Letters Patent as aforesaid,-
The arrangement and construction of the parts of pianos, as herein set forth, so
as to admit of the instrument being taken to pieces for the convenience of packing
and transport, and of the several parts being brought together again and properly
secured ready for use, as above described.
Second. I claim the application, as herein set forth, of drawn metal tubes to
pianos for the purpose of strengthening and tightening the same, and also of
improving or increasing the tone, as above described.
In witness whereof, I, the said François Christophe Tessereau, have hereunto
set my hand and seal, the Fifth day of February, in the year of our Lord
One thousand eight hundred and seventy-eight.
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