IMPROVE- MENTS IN THE CONSTRUCTION OF PIANOFORTES AND OTHER STRINGED INSTRUMENTS
Year: 1869

page_text: PROVISIONAL SPECIFICATION left by William Edward Gedge at the
Office of the Commissioners of Patents, with his Petition, on the
28th April 1869.-A communication from abroad by Frederic Bauer,
of 37, Boulevard Bonne Nouvelle, Paris, in the Empire of Franco.
I, WILLIAM EDWARD GEDGE, of the Firm of John Gedge and Son,
of No. 11, Wellington Street, Strand, in the County of Middlesex, Patent
Agent, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN THE CONSTRUCTION OF PIANOFORTES AND OTHER STRINGED INSTRUMENTS,"
a communication to me from abroad by Frederic Bauer, of 37, Boulevard
Bonne Nouvelle, Paris, in the Empire of France, to be as follows:-.
All persons occupied in the construction of pianos are aware that the.
united tension of all the strings, or chords of a piano constitutes a very
powerful traction necessitating a very rigid construction, failing which.
the two points to which the strings are attached come nearer to cach
other, the cords slacken, and the piano is no longer in tune. Endeavours
have long been made to secure this rigidity by using good and perfectly.
seasoned, wood, but however carefully chosen the wood is more or less
under the influence of the hydrometric action of the atmosphere, its.

page_text: fibres are penetrated by the mechanical action of the strings or chords
themselves, and it is even exposed in meridianal climates to rapid de-
struction of some of its essences by xylophagus insects. These defects
have suggested to the Inventor of the system the subject of this Invon-
tion, the idea of constructing the framing of pianos no longer exclusively
of wood but of wood and metal.
The accompanying Sheets of Drawing forming part of this Provisional
Specification represent the application of this Invention to an upright
piano, but it is equally applicable to every stringed instrument of
analogous description.
The end to be attained being the rigidity of and the maintenance
of an invariable distance between the head bar or pin plate in which
are fixed the ends of the pins and the lower bar, the construction of
this new system of barring or framing is intended, in the first place,
to oppose any drawing together of these two parts by the interposition
of rigid metallic bars of any shape, flat, square, or T shaped, and even
of hollow iron, and, in the second place, to prevent the head bar or pin
plate from being drawn by the traction of the strings from its primitive
vertical position and inclining towards the action of the strings. This
object is attained by the use of an arrangement of cramps applied on the
face apposite that on which the strings are placed.
Fig. III., Sheet 2, of the accompanying Drawings shows the framing
of an upright piano seen from the side on which the strings are carried;
Fig. I., Sheet 1, the same seen from the opposite side; Fig. II., Sheet 2,
a longitudinal and vertical section of same at e, f, g, h, Figs. I. and III.;
Fig. IV, transverse and horizontal section at b, c, d, Fig. I.; and Fig. V.,
a modification of the cranp or clamp arrangement. S indicating the
head bar or pin plate; T, lower bar; M, wooden uprights, which together
with the iron uprights F constitute the barring or framing. In these
Figs: the wooden and metal uprights are shown alternating, but they
might be joined together, the uprights F on those M. t, iron clamps
opposing any overturning of the head bar. The upper ends of the
uprights F rest on plates p screwed to the head bar and their lower
ends either upon the cast-iron sole plate P, to which the bass strings
are attached, or on a certain number of eye bolts I riveted in the
segment N to which the strings of the upper octaves are attached.
In order that the uprights F may not cause the plates p to penetrate
into the wood of the pin plate S these plates bear against the heads of

page_text: screws V sunk in the thickness of the wood and which serve to carry
the pressure from the surface to the interior of the wood. The clamps F
may be screw threaded in the plates p at their upper part and be fixed
at the lower parts by nuts sunk in the plate P, but these clamps might
also pass through the pin plate or head bar and be secured by a nut
sunk in the wood, as shewn at Fig. 5, where the plate p is dispensed
with, and where the upright Frests against one of two heads of screws V',
in this case much longer than those V previously described, the sunken
nut also rests upon two screws V. The clamps which correspond with
the eye bolts I pass through these latter and are fixed to them as
ordinary nuts. The uprights F are prevented from bending under the
traction of the strings by attaching them with wooden screws to small
wooden cross pieces B placed at various heights between the wooden
uprights M.