Improvements in Sounding-boards for Piano-fortes.
Year: 1893

page_text: Date of Application, 19th Aug., 1893-Accepted, 28th Oct., 1893
COMPLETE SPECIFICATION.
Improvements in Sounding-boards for Piano-fortes.
I, AUGUST BODEN of 9 Wernigeröderstrasse, Halberstadt, in the Kingdom of
Prussia, German Empire, Organ-builder, 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 a double sounding-board for grand and cottage pianos,
the sounding boards being of equal size and being alternately used for holding the
wires in chords of 4, 5 or 6; said wires being attached to divided double bridges,
so that each board carries half of the number of wires; surfaces free from wires
being left between the separate groups of each board.
In order to make this invention more fully intelligible reference is made to the
accompanying drawings in which similar letters are used to denote similar parts
throughout the several figures.
Fig. 1 represents a longitudinal section of a part of the two sounding-boards.
Fig. 2 is a plan of the arrangement of the bridges shown strung.
Fig. 3 is a cross-section of the double sounding-boards.
Fig. 4 is a plan of the whole arrangement, showing the upper sounding-board.
is the upper, and the lower board, a¹ and a² designating the bridges which
pass through the upper one, and which support the strings of the lower board.
and 2 are the bridges of the upper board.
The respective bridges of the two boards are united by connecting bridges.
On the surface of the upper board », the connecting-bridge runs in two parts d'
and d² (Fig. 2) parallel with the bridges and 2 supporting the wires. Ribs c¹ c¹
pass through these bridges; said ribs can however be laid below the board.
The lower sounding-board 2 (Fig. 1) has the connecting bridge d³ of the
bridges a and a² together with the ribs all on the under surface.
The bridges of the lower board are connected to this latter by means of separate
sounding blocks e (Fig. 3) in order to compensate for the differences in tone,
which arise from the different heights of the bridges.
The bridges (Figs. 1 and 2) a' and a² belong to the lower sounding-board and
pass up through suitable openings in the upper board to the wires. and 62 are the
bridges of the upper board, which alternate regularly with those of the lower
board.
e denotes the ribs of the upper and c2 (in dotted lines) the ribs of the lower
sounding-board.
Both boards are of the same size and form, and lie exactly one over the other.
The wire divisions are marked in the drawing (Fig. 4) by boundary lines i. Two
lines pass over each bridge, of which the one shows the position of the first wire
whilst the other line shows the position of the last wire of the group.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
Double sounding-boards for pianos, in which regularly alternating bridges from
the upper and lower boards carry the wires spread over the whole surfaces of the
two boards, so that each board carries half the number of wires, free surfaces,

page_text: uninfluenced by the pressure of wires being left to each side of the separate wire-
groups, substantially as herein described with reference to the accompanying
drawings.
Dated this 19th day of August 1893:
WHEATLEY & MACKENZIE,
40, Chancery Lane, London, W.C., Agents.