IMPROVEMENTS IN APPARATUS FOR REFRACTING, REINFORCING, AND MODULATING SOUND
Year: 1878

page_text: LETTERS PATENT to Adam Cyrus Engert, of Three Mills Lane, Bromley-by-
Bow, in the County of Middlesex, for the Invention of "IMPROVEMENTS IN
APPARATUS FOR REFRACTING, REINFORCING, AND MODULATING SOUND."
PROVISIONAL SPECIFICATION left by the said Adam Cyrus Engert at the
Office of the Commissioners of Patents on the 7th June 1878.
ADAM CYRUS ENGERT, of Three Mills Lane, Bromley-by-Bow, in the County of
Middlesex. "IMPROVEMENTS IN APPARATUS FOR REFRACTING, REINFORCING, AND
MODULATING SOUND."
This Invention has for its object improvements in apparatus for refracting, re-
inforcing, and modulating sound.
For this purpose I employ a sheet of iron, or it might be of wood or other hard
material, supported by two spiral or other springs attached to it at different points
on a line drawn through it, or it might be supported by a single spring.
Metal or other sheets thus suspended may be applied to musical instruments, as,
for example, to pianos, or they may be merely set up in any room or place in which
it is required to reinforce and modulate sound.
Instead of the sheet of metal being supported by springs as above described, it
might be coiled up into a spiral coil, and placed within a tubular casing, the outer-
most coil being attached to the interior of the casing, and such casings with the
coiled plates within them may be used wherever it is desired to reinforce and
modulate sound; or the coils may be used without the tubular casing.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by the
said Adam Cyrus Engert in the Great Seal Patent Office on the 6th December
1878.
ADAM CYRUS ENGERT, of Three Mills Lane, Bromley-by-Bow, in the County of
Middlesex. "IMPROVEMENTS IN APPARATUS FOR REFRACTING, REINFORCING AND
MODULATING SOUND."
This Invention has for its object improvements in apparatus for refracting, re-
inforcing, and modulating sound.
For refracting, reinforcing, and modulating sound in the interior of buildings, as,
for example, in churches or concert rooms, I suspend freely thin sheets of steel or
iron, or it might be wood or other hard material, to the walls on the inside of the
building, or suspend such plates from frameworks or stands erected for the purpose.
Each plate has two strips or coiled or other springs of metal attached to it-at
different points, and is by these secured to the wall or stand, or it might be sup-
ported from the wall or stand by a single strip or spring.
Plates supported by springs in the above manner can also be applied to musical
instruments, as, for example, to pianos, and be held in them either in a horizontal
or vertical position.
For a vertical piano the plate might, for example, be suspended at the back or
upper part of the front of the frame or case of the instrument, whilst for a hori-
zontal piano it might lie either at the top above the strings, or in the lower part of
the case below them, and be sustained by any desired number of springs. Similar
plates may also be applied to organs..
Plates carried in the above manner by stands can in like manner be employed in
the open air; or I employ a sheet of metal coiled up into a spiral coil or scroll, and
placed within a rectangular or other tubular casing, the outermost coil of the scroll
being attached to the interior of the casing, and such casings with the coiled plates
within them may be placed in different parts of the building, wherever it may be
required to use them. The sides of the casing may also have openings formed
through them.
Flat or slightly curved sheets or plates of metal may similarly be placed within a
casing, and be carried in the manner herein-before described by strips or springs
from the side of the casing.
Scrolls formed from metal plates may also be used without the casing, and
be secured by the outermost coils to the walls of the building or to frames or
stands.
The Drawing hereunto annexed shows examples of plates suspended in the
manner above described from the inner face of the wall of a building.
Figure 1 shows a plan view, and Figure 2 a face view of a plate sustained
by springs at a short distance from the face of a wall, it may be interior of a
church, concert room, or other building, where it is desirable that speaking or
singing shall be clearly heard in every part of the building. Any desired extent of
the surface of the wall of the building may thus have plates mounted in front of
them, according to the effect required to be produced. The plates also need not
be. mounted upon the wall of the building; they might be mounted at other parts
of its interior, or upon frames or stands provided for the
purpose.: The plates also
may either be flat, or, as I prefer, slightly curved.
The plates should be placed at that part or parts of the building near which is
produced the sound which it is desired to resound through the building, whilst at
other parts of the building provision may be made for preventing the re-echoing of
any sound made near them.

page_text: In Figures 1 and 2 A is part of the wall of the building; B, B, are two coiled
springs, or it might be strips of metal, secured to the wall and also to the plate C,
which may be of iron, or steel, or other hard metal or material; G, G, are other
very light springs for keeping the plates in position away from the wall.
In some cases a second plate D may similarly be carried by springs E from the
plate C, as shown at Figure 3. The springs E are by preference so placed that
a line drawn between them shall be at right angles to a line drawn between the
springs B.
Figure 4 shows a plate supported by a single spring at its centre.
Figure 5 shows a coiled plate A placed within a cylindrical or other shaped
casing B, the outer edge of the coiled plate being secured to the interior of the
casing by springs C. Such coiled plates however might be used without any pro-
tecting casing, and be secured to any part of a building or elsewhere, wherever it
is desired to reverberate sound.
In many cases it is desirable that provision should be made for arresting at
times the action of the reverberatory plates. This may be effected by means of
dampers brought against the plates whenever they are not required to be in
action. The dampers might be worked by wires from a treadle, or in other suitable
manner.
Not only will plates mounted on springs in the manner herein-before described
reverberate and throw back sound, but they can also be applied as a protection
from bullets and other projectiles, especially if two or more plates are mounted one
in front of the other, in the manner shown at Figure 3. With light plates of hard
material mounted in this manner, used as a protection against bullets and other
projectiles, a bullet if it struck one plate would, like sound, be thrown back, or
possibly it might glance from one plate to another, as the plates yield freely in
every direction, but it would not be able to penetrate through the shields.
An example of a shield constructed in the above manner is shown at Figures 6
and 7. The shield shown in these Figures is of an oval form, and suitable for
forming a protection for an ammunition wagon, or to serve as a protection for a small
number of troops. The form of the shield may however be varied in a great variety
of ways, so long as the face of the shield is composed of light metal plates freely
suspended by springs in the manner shown.
A is a framework composed of two horizontal oval rings tied together at intervals
by vertical uprights. Care plates of thin hardened sheet steel, attached by coiled
springs at top and bottom to the top and bottom rings of the frame. In front of
the plates C, and attached to them by coiled springs, are other similar plates D.
These latter plates are so placed as to cover over the spaces between the plates C.
Figure 8 shows a plan view on a larger scale of part of a similar shield made in
a straight line.
Having thus described the nature of my Invention, and the manner of performing
the same, I would have it understood that I claim,-
First. The employment of plates or scrolls of metal or other hard material sus
pended from the walls or other parts of buildings or to frames or stands, substan-
tially in the manner and for the purpose herein-before described.
Second. The employment, in combination with plates or scrolls so mounted, of
dampers to be brought against the plates or scrolls whenever they are not required
to be in action.
Third. The employment of flat or slightly curved plates supported by strips or
springs, as herein-before described, or of coiled plates forming scrolls, mounted
within tubular casings for refracting, reinforcing, and modulating sound.
Fourth. The employment, in combination with pianofortes, organs, and other
such like musical instruments, of plates of metal or other hard material sup-
ported on the frames of the instrument by springs, substantially as hercin-before
described.
Fifth. The employment of thin hard metal plates supported by springs in front

page_text: of a framework, substantially in the manner herein-before described, as a protection
from bullets and other projectiles.
In witness whereof, I, the said Adam Cyrus Engert, have hereunto set my
hand and seal, this Sixth day of December, in the year of our Lord One
thousand eight hundred and seventy-eight.
RITARDm
A. C. ENGERT. (L.B.)