Microtelephonic Apparatus for Divers.
Year: 1889

page_text: Date of Application, 27th Nov., 1889
Complete Specification Left, 26th Aug., 1890-Accepted, 11th Oct., 1890
PROVISIONAL SPECIFICATION.
Microtelephonic Apparatus for Divers.
I, ROBERT WREDEN of No. 35 Moshaiskaia St. Petersburg Russia, Doctor of
Medicine and Actual Councillor of State do hereby declare the nature of this invention
to be as follows:-
My invention relates to a microtelephonic apparatus which will enable a diver
under any depth of water to hold a perfectly intelligible and loud conversation with
persons situated above water, either on land or on board a vessel. It fulfills perfectly
all the requirements of diving operations, as firstly, it transmits in a perfectly
intelligible manner the speech either from the diver to those above water, or from
the latter to the diver, this never having been perfectly accomplished before; secondly
the diver can, if necessary, ring a signal bell at the station above water; thirdly the
apparatus is of strong construction and can be readily used even by unskilled divers,
because the electrical conductors are situated inside the air supplying tube of the
diver, while the telephone, microphone, and commutator for the signalling apparatus
or bell are situated inside the helmet; also, the apparatus at the above-water station
are contained in a portable strong casing that can be locked, and the current generator
consists of a dry battery. Fourthly this microtelephonic diver apparatus is so
constructed as to be readily adapted to any existing construction of helmets and air
tubes.
The microtelephonic apparatus consists of four principal parts: the microtelephonic
head gear, the microtelephonic apparatus of the diving helmet, the microtelephonic
devices of the air tube, and the microtelephonic apparatus of the above-water
station.
I. THE MICROTELEPHONIC HEAD GEAR OF THE DIVER.
This is shewn at Figs. 1, 2 and 3 of the drawings; it consists of an elastic
bandage of caoutchouc which is placed over the top of the head and is fastened
together by buttoning or otherwise under the chin.
On the inner surface is the telephone T and on the outer surface the microphone M.
from which a pliable double conducting wire leads to the pinching screws a a¹ of
the commutator Fig. 6 in the helmet. The conducting connecting wires a" at which
connect the microphone M with the telephone T are on the inner surface of the
bandage, as shewn at Fig. 1. The microphone and telephone may be of any known
construction, they must however be of such size and configuration that they do not
interfere with the free movement of the head in the helmet.
It is also essentially necessary that the telephone should be tightly pressed against
the ear so as to protect this from the great noises occuring in the helmet, for which
purpose there is fixed on the edge of the ear-plate of the telephone a ring b", Figs. 1
and 3, of caoutchouc, felt, or other soft non-conductor of sound.
The shape of microphone head-bandage of the diver can also be varied; for
example it might be in the shape of a cap or covering with ear lappets; the principal
condition is that the telephone and microphone shall be fixed on the head of the diver,
and be prevented from coming in contact with the sides of the helmet, as otherwise
the sound vibrations produced in the helmet by the continuous inflow and outflow of
compressed air would be communicated to the microphone and destroy its proper
action or render speech unintelligible.
it
The material of which the head bandage is made may also be greatly varied; thus
he of caoutchouc leather felt, cloth &c.
may
It is only essential that the bandage should protect the ears as completely as possible
against the noises in the helmet, and should press the telephone tightly against the

page_text: head in whatever position this may be placed, so that the diver may be enabled to
hear everything that is spoken to him through the telephone, and therefore shall not
require any call signal from the station above water. If on the other hand the
telephone were fixed on the inner surface of the helmet the diver could not possibly
keep his ear pressed against for a considerable length of time, and could therefore
not at all times answer any question that might be put to him from the upper station.
It would therefore be necessary to provide a special call-signal in the helmet for
calling the divers attention to the fact that the upper station desires to speak with
him, which arrangement would be very inconvenient in view of the want of space
and the great noise occuring in the helmet. With the use of the microphonic head-
bandage the ears are effectually closed against the noise in the helmet; the microphone
is not subject to the vibrations of the helmet, and consequently transmits the divers
specchi clearly to the upper station while, as before stated, the telephone being pressed
continuously against the divers ear, renders a call signal unnecessary, as every sound
transmitted from above passes direct into the ear of the diver, as though it were
spoken directly into the same. The fixing of the microphone on the head of the
diver would also have the advantage of enabling those at the upper station to at
once detect by the occurance of unusual stillness or of sounds of snoring, if the
diver had gone to sleep, and to wake him by making loud or shrill noises through the
telephone.
II. THE MICROTELEPHONIC DEVICES IN THE HELMET.
These consist of a commutator, the necessary screw terminals for the conducting
wire of the air tube, and the modified construction of the air discharge valve.
1. The commutator of the helmet is shewn at Figs. 6 and 7; it enables the diver,
by depressing the button to cut his microphone and telephone out of the electric
circuit and to cause the current which passes from the battery at the upper station
along the wires of the air tube to the commutator, to pass directly back to the battery
through an electric signal apparatus so as to call the attention of the person at such
station.
The commutator is fixed on an insulating plate A of ebonite on the inner surface
of the helmet and is so constructed that the current passing through the metal
bracket c into the axis of the metallic lever d can pass in two different directions,
namely either to the right through the right contact stud and the right hand screw
terminal a¹ connected thereto into the microphone and telephone of the diver, from
which it passes back through the left screw terminal a and the contact stud bin
connection therewith to the battery of the upper station; or, upon the diver pressing
his head against the button k of the lever d thereby breaking the contact at 61, and
making it at b, the current will pass directly back to the battery of the upper station,
cutting out the microphone and telephone of the helmet. As the principal use of the
apparatus is to transinit speech to and from the diver, the commutator lever is acted
upon by a spring f so as to cause it to keep in contact with the contact stud b¹, and
thus keep the circuit ordinarily closed through the microphone and telephone.
2. The terminal connection of the helmet, Figs. 6 and 7, for attaching the con-
ducting wires is connected to the commutator base and passes in a watertight manner
through the side of the helmet to the outside thereof. It consists of an ebonite
cylinder with two internal insulated metal tubes e e¹ which are in conducting connection
with the metal contact stud band support c of the commutator, and serve to receive
the two metal pins S S' of the cap D, which is in connection with the branch E of
the air tube F Fig. 5. The outer metallic covering to the block B is formed with a
screw thread for receiving the screw cap D of the terminal block C of the air tube.
Between the two blocks B and C a caoutchouc washer is introduced to prevent
the possibility of water penetrating to the conductors.
3. The air-escape valve of the helmet Fig. 4, has, in place of a great number of
escape openings, as is customary, through which the excess of air escapes into the
water, only a single comparatively large opening O situated in the centre of a lead
ring P soldered on to the end of the valve casing. This arrangement has for its

page_text: can either be directed into the microphone V, the lever being put upon the stud m,
or into the bell X, the lever being put upon the stud n.
In the first case the microphone is put into circuit and the bell is out of circuit,
and in the latter case the reverse is effected.
For communicating with the diver, the commutator lever N is moved to the left,
whereupon the current passes from the stud m and screw terminal Z into the
microphone V of the upper station, in passing through the screw p into the thick
wire of the induction coil and the carbon contact, and thence through the screws g
and to the terminal S of the circuit wire in the air pipe; from the other end of this
it passes into the commutator of the divers helmet. Here the current passes through
the axis e of the moveable contact lever d and contact stud to the screw terminal a
with which the one end of the pliable conducting wire a Fig. 2 of the divers
microphone is connected.
After the current has passed through the microphone, and the telephone connected
parallel therewith, it passes through the contact screw a and stud b of the helmet
commutator into the circuit wire of the air tube F, and from the terminal S' hereof
to the zinc pole of the battery W.
The parallel arrangement of the microphone and telephone of the divers apparatus
is an essential peculiarity of the apparatus, because it produces a remarkable degree
of effectiveness of the apparatus. In connecting the microphone with its telephone
in series, the introduction of the induction coil of the telephone into the circuit
would cause a considerable resistance to the battery current, whereby the action of
the two microphones at the divers apparatus and upper station would be considerably
weakened.
To avoid this defect, it would be necessary, if the above described parallel arrange-
ment were not employed, to introduce another induction coil into the divers helmet,
thereby still further reducing the space in the same, which is already very limited,
and causing great inconvenience.
After the termination of the conversation, the person at the upper station places the
lever N upon the stud n, whereby the microphone V is cut out and the bell X is
included in the circuit.
This bell will however not ring so long as the microphone and telephone of the
diver are included in the circuit, but is only brought into action after these have been
cut out by the action of the lever d as above described, thereby causing the current
to pass from the commutator direct to the zinc pole of the battery W, whereupon the
bell X, being alone in circuit, will be effectually put in action. The current then flows
as follows: From lever N and stud n the current passes into the bell X from thence
through screw S into the circuit wire of the air tube F, and through this to the
commutator of the helmet, where it passes through lever d, this being depressed by
the diver, and post b to the other wire of the air. tube and thence through screw S to
the battery W.
If it is desired to use the earth or water for return conductor instead of having a
second wire, the apparatus will also act efficiently, the two microphones, two telephones
and the electric bell being then worked by a single wire.
Dated this 27th day of November 1889.
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Microtelephonic Apparatus for Divers.
I, ROBERT WREDEN of No. 35 Moshaiskaia St. Petersburg Russia, Doctor of 50
Medicine and Actual Councillor of State, do hereby declare the nature of this inven-
tion 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 a microtelephonic apparatus which will enable a diver
under any depth of water to hold a perfectly intelligible and loud conversation with 55

page_text: persons situated above water, either on land or on board a vessel. It fulfills perfectly
all the requirements of diving operations as firstly it transmits in a perfectly intel-
ligible manner the speech either from the diver to those above water, or from the
latter to the diver, this never having been perfectly accomplished before; secondly
the diver can, if necessary ring a signal bell at the station above water; thirdly the
apparatus is of strong construction and can be readily used even by unskilled divers
because the electrical conductors are situated inside the air supplying tube of the
diver, while the telephone, microphone, and commutator for the signalling apparatus
or bell are situated inside the helmet; also, the apparatus at the above-water station
are contained in a portable strong casing that can be locked, and the current generator
consists of a dry battery. Fourthly this microtelephonic diver apparatus is so con-
structed as to be readily adapted to any existing construction of helmets and air tubes.
The microtelephonic apparatus consists of four principal parts; the microtelephonic
head gear, the microtelephonic apparatus of the diving helmet, the microtelephonic
devices of the air tube, and the microtelephonic apparatus of the above-water station.
I. THE MICROTELEPHONIC HEAD GEAR OF THE DIVER.
This is shewn at Figs. 1 2 and 3 of the drawings accompanying my Provisional
Specification it consists of an elastic bandage of caoutchouc which is placed over the
top of the head and is fastened together by buttoning or otherwise under the chin.
On the inner surface is the telephone T and on the outer surface the microphone M,
from which a pliable double conducting wire leads to the pinching screws a a¹ of the
commutator Fig. 6 in the helmet. The conducting connecting wires a all which
connect the microphone M with the telephone T are on the inner surface of the
bandage, as shewn at Fig. 1. The microphone and telephone may be of any known
construction, they must however be of such size and configuration that they do not
interfere with the free movement of the head in the helmet.
It is also essentially necessary that the telephone should be tightly pressed against
the ear so as to protect this from the great noises occuring in the helmet, for which
purpose there is fixed on the edge of the ear plate of the telephone a ring 6, Figs. 1
and 3 of caoutchouc, felt, or other soft non-conductor of sound.
The shape of microphone head-bandage of the diver can also be varied; for example
it might be in the shape of a cap or covering with ear lappets; the principal con-
dition is that the telephone and microphone shall be fixed on the head of the diver,
and be prevented from coming in contact with the sides of the helmet, as otherwise
the sound vibrations produced in the helmet by the continuous inflow and outflow of
compressed air would be communicated to the microphone and destroy its proper
action or render speech unintelligible.
The material of which the head bandage is made may also be greatly varied; thus
it may be of caoutchouc leather felt, cloth &c.
It is only essential that the bandage should protect the ears as completely as
possible against the noises in the helmet, and should press the telephone tightly
against the head in whatever position this may be placed, so that the diver may be
enabled to hear everything that is spoken to him through the telephone, and there-
fore shall not require any call signal from the station above water. If on the other
hand the telephone were fixed on the inner surface of the helmet the diver could not
possibly keep his ear pressed against for a considerable length of time, and could
therefore not at all times answer any question that might be put to him from the
upper station. It would therefore be necessary to provide a special call-signal in the
helmet for calling the divers attention to the fact that the upper station desires to
speak with him, which arrangement would be very inconvenient in view of the want
of space and the great noise occuring in the helmet.
With the use of the microphonic head-bandage the ears are effectually closed against
the noise in the helmet; the microphone is not subject to the vibrations of the helmet,
and consequently transmits the divers speech clearly to the upper station, while, as
before stated the telephone being pressed continuously against the divers ear, renders

page_text: a call signal unnecessary, as every sound transmitted from above passes direct into
the ear of the diver, as though it were spoken directly into the same. The fixing of
the microphone on the head of the diver would also have the advantage of enabling
those at the upper station to at once detect by the occurence of unusual stillness or of
sounds of snoring, if the diver had gone to sleep, and to wake him by making loud
or shrill noises through the telephone.
II. THE MICROTELEPHONIC DEVICES IN THE HELMET.
These consist of a commutator, the necessary screw terminals for the conducting
wire of the air tube, and the modified construction of the air discharge valve.
1. The commutator of the helmet is shewn at Figs. 6 and 7, it enables the diver by
depressing the button k to cut his microphone and telephone out of the electric circuit
and to cause the current which passes from the battery at the upper station along the
wires of the air tube to the commutator to pass directly back to the battery through
an electric signal apparatus so as to call the attention of the person at such station.
The commutator is fixed on an insulating plate A of ebonite on the inner surface of
the helmet and is so constructed that the current passing through the metal bracket c
into the axis of the metallic lever d can pass in two different directions, namely,
either to the right through the right contact stud and the right hand screw
terminal a¹ connected thereto into the microphone and telephone of the diver, from
which it passes back through the left screw terminal a and the contact stud 6 in con-
nection therewith to the battery of the upper station; or, upon the diver pressing
his head against the button k of the lever d thereby breaking the contact at b¹, and
making it at b, the current will pass directly back to the battery of the upper station,
cutting out the microphone and telephone of the helmet. As the principal use of the
apparatus is to transmit speech to and from the diver, the commutator lever is acted
upon by a spring f so as to cause it to keep in contact with the contact stud b', and
thus keep the circuit ordinarily closed through the microphone and telephone.
2. The terminal connection of the helmet, Figs. 6 and 7, for attaching the conducting
wires is connected to the commutator base and passes in a watertight manner through
the side of the helmet to the outside thereof. It consists of an ebonite cylinder
with two internal insulated metal tubes e e¹ which are in conducting connection with
the metal contact stud 6 and support c of the commutator, and serve to receive the
two metal pins S S¹ of the cap D, which is in connection with the branch E of the
air tube F, Fig. 5. The outer metallic covering to the block B is formed with a screw
thread for receiving the screw cap D of the terminal block C of the air tube.
Between the two blocks B and C a caoutchouc washer is introduced to prevent the
possibility of water penetrating to the conductors.
3. The air-escape valve of the helmet Fig. 4 has, in place of a great number of
escape openings, as is customary, through which the excess of air escapes into the
water, only a single comparatively large opening O situated in the centre of a lead
ring P soldered on to the end of the valve casing. This arrangement has for its
object to lessen the disturbing noise in the helmet, which is caused by the issue of
the air through a large number of small openings, as a single jet of air will produce a
considerably less number of vibrations in the water and consequently in the helmet
than a number of them, and in addition the friction of the air in a number of small
passages will be much greater than in a single large one. Lastly, the sound vibrations
will be much less in the comparatively bad sound conductor, lead, than in the brass
plate containing the number of small holes, and the transmission of such sound to the
helmet will also be much less through the lead than through the brass. In place of
lead any other bad conductor of sound such as caoutchouc, cork, felt, &c., might be
used. In order to still further reduce the noise the helmet might be lined internally
with one of the above named substances, because the transmission of the sound
vibrations of the helmet to the enclosed air would be considerably impeded thereby.
This effect may be still further increased by coating the helmet both internally and
externally with a bad conductor of sound.

page_text: The principal cause of noise in the helmet is the outflowing air; that caused by
the inflowing air is comparatively small and it is not even desirable to do away with
this, such as by improved constructions of the air pump and of the air-inlet passages
of the helmet, because by that means the indication at the upper station by the
microphone, of the sufficient and regular supply of air to the helmet would be
impaired.
III. THE MICROTELEPHONIC DEVICES OF THE AIR TUBE
Fig. 5 consist in providing at both ends thereof, i.e. at the helmet and at the air
pump, two lateral caoutchouc branch tubes E E¹, through which the electric circuit
wires contained in the air tube F pass out, in order to avoid the air valves at the
helmet and air pump.
These two branch tubes E E' have at their ends hermetically secured terminals for
connecting the circuit wires of the air tube with the commutator of the helmet and
the connecting screws S S¹ of the upper station, as indicated at Figs. 9 and 10.
The terminal on the air tube for connection with the helmet consists of an ebonite
cylinder C. Fig. 6 in which are bedded two projecting metal pins s s¹ which are in
conducting connection with the circuit wires of the air tube, and which fit closely
within the metal tubes e e¹ of the commutator terminal on the helmet.
The metallic casing of the ebonite cylinder O is contained loose in a metal screw
cap 1) that screws on the terminal of the helmet, whereby an effectual conducting
contact between the two sets of terminals is effected.
The terminal at the end of the branch E¹ consists of an ebonite block containing
two metal conducting tubes k¹ which are in conducting connection with the circuit
wires in the tube, and which have pinching screws for securing the connecting
wires S S¹ Figs. 9 and 10 inserted into the tubes at the upper station.
IV. THE MICROTELEPHONIC ABOVE-WATER STATION
Figs. 9 and 10 consists of a transportable wooden box that can be locked up, and
that contains three compartments.
In the first of these K is the microphone with the induction coil and telephone;
in the second L are three dry battery elements, and in the third R is the electric
signalling bell and the commutator. This commutator shewn at Fig. 8 sends the
current of the battery through the left hand metal stud m into the microphone on
turning the switch N to the left hand; on moving the switch to the right hand on to
stud n,
the current is sent into the signal bell, while it the switch is turned to the
middle position, on the insulating ebonite plate, the circuit is intercepted and
consequently the battery is at rest.
The function of the microtelephonic apparatus will be seen from the diagram of
the electrical connections Fig. 10. From the positive pole of the battery W the
current passes into the axis of the commutator lever N, and by turning the latter, it
can either be directed into the microphone V, the lever being put upon the stud m or
into the bell X, the lever being put upon the stud n.
In the first case the microphone is put into circuit and the bell is out of circuit,
and in the latter case the reverse is effected.
For communicating with the diver, the commutator lever N is moved to the left,
whereupon the current passes from the stud m and screw terminal Z into the micro-
phone V of the upper station, in passing through the screw p into the thick wire of
the induction coil and the carbon contact, and thence through the screws q and Z' to
the terminal S of the circuit wire in the air pipe; from the other end of this it
passes into the commutator of the divers helmet. Here the current passes through
the axis c of the moveable contact lever d and contact stud b' to the screw terminal a¹
with which the one end of the pliable conducting wire a¹¹ Fig. 2 of the divers
microphone is connected.
After the current has passed through the microphone, and the telephone connected
parallel therewith, it passes through the contact screw a and stud b of the helmet

page_text: commutator into the circuit wire of the air tube F, and from the terminal S¹ hereof
to the zinc pole of the battery W.
The parallel arrangement of the microphone and telephone of the divers apparatus
is an essential peculiarity of the apparatus, because it produces a remarkable degree
of effectiveness of the apparatus. In connecting the microphone with its telephono
in series, the introduction of the induction coil of the telephone into the circuit
would cause a considerable resistance to the battery current, whereby the action of
the two microphones at the divers apparatus and upper station would be considerably
weakened.
To avoid this defect, it would be necessary, if the above described parallel arrange-
ment were not employed, to introduce another induction coil into the divers helmet,
thereby still further reducing the space in the same, which is already very limited,
and causing great inconvenience.
After the termination of the conversation, the person at the upper station places
the lever N upon the stud n, whereby the microphone V is cut out and the hell X
is included in the circuit.
This bell will however not ring so long as the microphone and telephone of the
diver are included in the circuit, but is only brought into action after these have been
cut out by the action of the lever d as above described, thereby causing the current
to pass from the commutator direct to the zinc pole of the battery W, whereupon
the bell X, being alone in circuit, will be effectually put in action.
The current then flows as follows:-From lever N.and stud n the current passes
into the bell X from thence through screw S into the circuit wire of the air tube F,
and through this to the commutator of the helmet, where it passes through lever d,
this being depressed by the diver, and post 6 to the other wire of the air tube and
thence through screw S to the battery W.
If it is desired to use the earth or water for return conductor instead of having a
second wire, the apparatus will also act efficiently, the two microphones, two tele-
phones and the electric bell being then worked by a single wire.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed I declare that what I claim is :-
1. A microtelephonic apparatus for attachment to the head of a diver with parallel
connection of the microphone and telephone constructed substantially as herein
described with reference to Figs. 1 2 & 3 of the drawings.
2. The combination with a divers helmet of a commutator with moveable contact
lever, which, in a state of rest establishes the connection between the microtelephonic
apparatus referred to in the preceding claim and the station above water, while by
depressing the same by means of the head of the diver the full current is sent through
the signal bell of the said station, substantially as described with reference to Figs. 6
and 7 of the drawings.
3. The improved construction of the air outlet valve of a divers helmet, having
one large escape opening instead of a number of small ones, such opening being
lined with lead or other bad conductor of sound, substantially as described with
reference to Fig. 4.
4. The arrangement of electric circuit wires in the air supply pipe of the divers
helmet, and the provision on such pipe of branch pipes near each end, through which
the insulated wires leading to the electrodes pass, substantially as described with
reference to Figs. 5, 6 & 7 of the drawings.
5. The general arrangement and combination of parts constituting a micro-
telephonic apparatus for divers and its connection with the station above water,
substantially as herein described.
Dated this 26th day of Amunt 100
ABEL & IMRAY,
Agents for the Applicant.