IMPROVEMENTS IN PIANOFORTE SOUNDING BOARDS to be as follows:
Year: 1884

page_text: I WILLIAM HENRY DREAPER of N° 96 Bold Street Liverpool in the County of
Lancaster, Pianoforte Manufacturer, do hereby declare the nature of my said
invention for " IMPROVEMENTS IN PIANOFORTE SOUNDING BOARDS to be as
follows:-
"
The object of my invention is to improve the tone, augment the volume and
equalize and lengthen vibration in pianofortes. .
I have ascertained that the sounding boards heretofore used have a decided
deficiency in vibratory power. To remedy this defect or deficiency I so construct
sounding boards that all parts of the same vibrate equally and hence have improved
tone and give in use greater volume of sound.
.
In carrying my invention into practice I under one modification, with the bridge
in the usual position in relation to the scale, attach to the sounding board, between
the bridge and the wrest plank, a truss or trusses, such truss or trusses being longer
or shorter as required and being attached to the sounding board by screws glue or
other ordinary or convenient means.
Another modification consists in making the sounding board of varying thick-
ness of wood between the bridge and wrest plank and from front to back. A like
effect is secured by strengthening or thickening sounding board bars such as are ·
now in use in the part between the bridge and wrest plank.
By my improvements there is secured an advantage of about thirty per cent in
the length of tone and nearly fifty per cent in volume.
J. T. KING,
Per J. Johnson,
Agent for the Applicant.

page_text: CUATE LEIE
SPECIFICATION
"
I WILLIAM HENRY DREAPER of No 96 Bold Street Liverpool in the County of
Lancaster Pianoforte Manufacturer do hereby declare the nature of the said
invention for "IMPROVEMENTS IN PIANOFORTE SOUNDING BOARDS and in what
manner the same is to be performed, to be particularly described and ascertained in
and by the following statement :-
The object of my invention is to improve the tone, augment the volume and
equalize and lengthen vibration in pianofortes.
'
I have ascertained that the sounding boards heretofore used have a decided
deficiency in vibratory power. To remedy this defect or deficiency I so construct
sounding boards that all parts of the same vibrate equally and hence have improved
tone and give in use greater volume of sound.
;
In carrying my invention into practice I, under one modification, with the bridge
in the usual position in relation to the scale, attach to the sounding board, between
the bridge and the wrest plank, a truss or trusses, such truss or trusses being longer
or shorter as required and being attached to the sounding board by screws, glue or.
other ordinary or convenient means..
Another modification consists in making the sounding board of varying thickness
of wood between the bridge and wrest plank and from front to back.
A like effect is secured by strengthening or thickening the sounding board bars
such as are now in use in the part between the bridge and wrest plank.
By my improvements there is secured an advantage of about thirty per cent in
the length of tone and nearly fifty per cent in volume.
DESCRIPTION OF THE DRAWINGS.
.
Fig 1 is a section, and fig 2 a back view of a sounding board made in accordance
with the first part of my invention a bracing of frame, b wrest plank, c bridge,
d strings, e sounding board, f struts attached to the sounding board between the
bridge and the wrest plank so as to strengthen the sounding board in the positions
required to give increased vibration. The number and positions of the struts may
be varied, g ordinary bars.
Fig 3 is a section, and fig 4 a front view of part of a piano forte in which á
strut ƒ is attached to the sounding board and bridge instead of being secured
between the ordinary bars g as shown in figs 1 and 2.
Fig 5 shows a strut f formed with the sounding board and with the bridge fitted
or attached thereto.
Under the second part Fig 6 is a section and fig 7 a plan showing the sounding
board thickened both back and front at between the bridge e c and wrest
plank b.
Fig 8 is a section, showing a similar thickening of the sounding board in front
only. The said sounding board may be thickened at the back only instead of in
the front.
Under the third part, Fig is a section showing the struts of made with or
attached to the backs of the ordinary bars g.

page_text: In fig 10 the struts f are made with or attached to the sides of the said ordinary
bars g.
It will be obvious that in some instruments it may be desirable to combine two
or more of the systems of increasing the vibratory power of sounding boards,
and that my invention may be applied during or after the construction of the
pianoforte.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is
First. The improvements in pianoforte sounding boards herein setforth.
Second. Combining with pianoforte sounding boards a truss or trusses between
the bridge and wrest plank for the purpose setforth.
Third. Constructing sounding boards for pianofortes with a portion or portions
of increased strength between the bridge and the wrest plank for the purpose.
setforth.
Fourth. Combining with pianoforte sounding board bars strengthened between
the bridge and wrest plank for the purpose setforth.