IMPROVEMENTS IN MICROPHONES
Year: 1884

page_text: I FRANCOIS JOSEPH SEMAL of Mons in the Kingdom of Belgium Doctor of
Medicine do hereby declare the nature of the said Invention for "IMPROVEMENTS
IN MICROPHONES" to be as follows:-
My invention relates to an improved construction and arrangement of micro-
phones which I call simplex microphones.
Upon a suitable vibrating plate or flat piece of wood, cork, ebonite, metal or
other suitable material capable of vibrating under the shock of a wave of sound
hereinafter called the "plate" I affix two small cylinders of hard carbon or other
suitable material disposed parallel one to the other and so as to be near each
other say from about one eighth to three eighths of an inch apart more or less
according to circumstances. The two small cylinders are bevilled at one end and
are by their bevilled end glued onto or otherwise attached to the plate so as to
project therefrom either upwards or downwards in an inclined or slanting direction
so as to form an angle with the plate-one of the said small cylinders is in commu-
nication with a telephone whilst the other receives the current from the electric
pile.
.7
The circuit is completed by a little ball of the same material as the cylinders
which ball is placed freely upon and between the cylinders and when the said
cylinders incline upwards the ball rests not only upon the said cylinders but bears
also against a point of support behind it or against the plate itself. When the
said cylinders incline downwards from the plate the said ball bears against a cross
piece of carbon or suitable material disposed parallel to the plate and in front of
it. The mobility of the little ball under the influence of the vibratory changes
produced by the shock of the waves of sound upon the plate is amply sufficient
to cause variations in the intensity of the current
In order to prevent the little ball from falling when the apparatus is removed
the said little ball is traversed by a thread the ends of which are fixed to the plate
and the tension of the said thread may also serve to regulate the pressure of the
ball upon the cylinders.
Dated this thirty first dose of Mauch 1001

page_text: I FRANCOIS JOSEPH SEMAL of Mons in the Kingdom of Belgium Doctor of
Medicine do hereby declare the nature of my Invention for "IMPROVEMENTS IN
MICROPHONES and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement:---
"
My invention relates to an improved construction and arrangement of micro-
phones which I call simplex microphones.
Upon a suitable vibrating plate or flat piece of wood cork ebonite metal or other
Buitable material capable of vibrating under the shock of a wave of sound herein-
after called the "plate" I affix two small cylinders of hard carbon or other suitable
material disposed parallel or nearly parallel one to the other and so as to be near
each other say from about one eighth to three eighths of an inch apart more or less
according to circumstances. The two small cylinders are bevilled at one end and
are by their bevilled end glued onto or otherwise secured to the plate so as to
.project therefrom either upwards or downwards in an inclined or slanting direction
so as to form an angle with the plate one of the said small cylinders is in commu-
nication with a telephone whilst the other receives the current from the electric
pile.
i
The circuit is completed by a little ball of the same material as the cylinders
which ball is placed freely upon and between the cylinders and when the said
cylinders incline upwards the ball rests not only upon the said cylinders but bears
also against a point of support behind it or against the plate itself. When the
said cylinders incline downwards from the plate the said ball bears against a cross
piece of carbon or suitable material disposed parallel to the plate and in front of
it. The mobility of the little ball under the influence of the vibratory changes
produced by the shock of the waves of sound upon the plate is amply sufficient to
cause variations in the intensity of the current.
In order to prevent the little ball from falling when the apparatus is removed
the said little ball may be traversed by a thread the ends of which are connected
to the plate and the tension of the said thread may also serve to regulate the
pressure of the ball upon the cylinders.
Having now explained the nature of my said invention I will proceed to
describe with reference to the accompanying drawings in what manner the same
is to be performed.
Figure 1 represents in front elevation a microphone constructed according to
my invention Figure 2 is a side view of the same partly in section and Figure 3
is a plan of the same partly in section.
a is a vibratory plate or flat piece of wood cork ebonite metal or other material
capable of vibrating under the shock of a wave of sound called "the plate" b b are
two small cylinders of hard carbon or other suitable material affixed by their lower
ends to the plate a and projecting upwards therefrom in an inclined direction one
of the said cylinders 6 communicates by a suitable wire with a telephone and the
other cylinder b receives the current from the electric pile. c is a small sphere or
ball of the same material as the cylinders 6 the said sphere or ball c is either placed
freely upon and between the cylinders 6 so as to bridge them over and rest against
the plate a or it may be traversed by a thread d the ends of which are secured
to the plate a as shown in the drawing. Figures 4 and 5 represent in front eleva-
tion and side elevation respectively a modification of the arrangement shown in
Figure 1 Qond

page_text: a is the plate bb are the small carbon cylinders which project upwards in a
slanting and diagonal direction from the plate a, o is the small carbon sphere
or ball which rests upon the cylinders b b. Figures 67 and 8 represent another
modification of the arrangement of parts shown in Figures 1, 2 and 3 Figure 6
being a front view Figure 7 a side view and Figure 8 a plan view.
a is the plate bb are the small carbon cylinders which project from the plate
horizontally in a diagonal direction the outer ends of the said cylinders b b being
inclined one towards the other c is the small carbon sphere or ball resting upon
the cylinders b b.
Figures 9 and 10 represent a front elevation and a side view respectively of a
microphone constructed according to my invention in which the carbon cylinders b b
project downwards in a slanting direction from the plate a to which they are
attached by their upper ends c is the carbon ball suspended to the plate a by the
thread d.
Figures 11 and 12 are respectively a front elevation and a side view representing
a modification of the microphone represented in Figures 9 and 10. In Figures 11
and 12 the carbon ball c instead of being connected to the plate a by means of the
thread d rests freely upon and between the carbon cylinders b b and a transverse
bar f placed in front of the carbon cylinders bb and forming with them a third
support for the ball c.
One or several of the microphonic elements hereinbefore described
affixed upon the same plate or diaphragm.
may be
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 A microphone consisting of a vibratory plate or diaphragm from which
project in a slanting direction two small carbon cylinders affixed thereto by their
ends one of the said cylinders being in communication with a telephone whilst
the other receives the current from an electric pile, and the circuit being com-
pleted by a small carbon ball placed freely upon or against and between the said
cylinders substantially as hereinbefore described and illustrated in the accompanying
drawings.
Secondly In a microphone the combination of a vibratory diaphragm two
cylindrical electrodes secured to the diaphragm in proximity one with the other
and a spherical electrode bridging the space between the two cylindrical electrodes
and in superficial contact with the exterior and convex surfaces of both the latter
substantially as described.
Dated this twenty third day of December 1884.