Improvements in Apparatus for Use in connection with Wireless Telegraphy.
Year: 1899

page_text: Date of Application, 2nd Feb., 1899-Accepted, 15th July, 1899
COMPLETE SPECIFICATION.
Improvements in Apparatus for Use in connection with Wireless
Telegraphy.
We, MAX JULIUS NEHEMIAS and HEINRICH FRIEDRICH AREND SCHRÖDER, both
of 73, Kleine Gärtnerstrasse, Altona (near Hamburg), in the Empire of Germany,
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:-
In the invention hereinafter described, we employ the peculiar property of
electrical waves, discovered by Marconi and made known by his researches and
those of Professor Slaby and others, of imparting to an electrical high resistance
consisting of loosely arranged metal filings or the like a sudden and considerable
conductive capacity.
In accordance with my invention, each vessel to which it is to be applied is
provided with an apparatus adapted for emitting such electrical waves, and also
with a suitably constructed receiving apparatus.
The apparatus in question is intended more especially for use in foggy weather
and at night, in order that the navigating officers of vessels which are approaching
one another, may be mutually notified of the fact. Such notification of the
approach of another vessel is afforded by means of an acoustic or optical signal
which is produced by the apparatus repeatedly and which is perceptible to each
navigator on board his own vessel directly by the medium of his own perceptive
organs.
"When the attention of the officer has been attracted by means of such a signal,
the device hereinafter described enables the officers in command of both vessels
to consult together as to the course to be followed, and thus avoid the danger of
collison which is so great in foggy weather.
The electrical waves are an accompanying phenomenon of a difference in
electrical potential resulting in the passage of compensating quantities of high
tension electricity over a sparking space.
In the accompanying drawing the device as a whole is diagrammatically
represented.
The sparking and the production of electrical waves thereby caused, may
advantageously be produced by means of an induction coil.
In the drawing 1 is the primary coil of the induction coil. Current is supplied
to this primary coil from a battery 2, this current taking the following path;
From 2 through the conductor 3 to the coil 1, then by means of the conductors 4
and 5 over the interrupting device 6 which is driven by a motor, through the
conductors 7, 8 the switch 9 in the position 1, the conductor 10, contact wheel 11
and conductor 12 back to the battery.
The motor actuating the diagrammatically indicated interruptor, and which by
means of a lever either causes the whole apparatus to act or throws it out of
action upon the lifting of the fog, is not shewn.
Each time that the current is interrupted there is present in the secondary coil 13

page_text: a powerful extra current which charges the electrical capacities 14, 15, 16 and 17
in such a manner, that, between 14 and 15, 17 and 16 and 15 and 16 powerful
sparking takes place whilst compensation is being effected. As the interruptions
of the current take place with great rapidity, an intense stream of sparks is
generated between the electrical capacities, and this is maintained as long as the
contact pieces 18 and 19 of the disc 11, which rotates in the direction indicated
by the arrow, continue to move under the contact springs 20 and 21 of the
conductors 10 and 12.
The interruption sparks are rendered harmless to as great an extent as possible
for the purpose of obtaining greater intensity in the secondary current, by means
of a condenser 22 interposed between the polar extremities of the interruptor in
the known manner.
L
The receiver is constituted in the manner of the known Marconi coherer, by
means of a glass tube with galvanometer relay and trembler.
Within the glass tube 23, where the conductor passing through it is interrupted
at 24, metal filings or the like are loosely arranged. When an electrical wave
encounters these metal-filings, these latter lose the resistance which they normally
offer to the passage of an electric current owing to their loose arrangement.
The path for the current is then formed in the receiving apparatus in the follow-
ing manner. From the battery 25 through the contact spring 26 over the con-
tact pieces 18 and 19 of the rotating disc 11, through the contact spring 27,
switch 28 in the position 1, the conductor 29, galvanometer relay 30, conductor 31,
glass tube 23, conductor 32-33, switch 34 in the position 1 and conductor 35 back
to the battery 25.
This path for the current remains closed as long
as the contact pieces of the
disc 11 move beneath the contact springs 26 and 27. During the same time
the galvanometer relay remains under the influence of the current and the pointer
has been drawn in the direction of the arrow I, thereby closing a circuit by means
of the contacts 36 and 37 which by means of a source of current 38 kindles a
lamp 39.
So far the apparatus described presents no novelty in its constituent parts.
In order to adapt this known apparatus for the purpose of signalling at sea, how-
ever, in addition to suitably arranging the apparatus a device must be provided
which will maintain the receiver out of action so long as the transmitting
apparatus on board the same vessel is operating. A device must also be provided
which leaves no room for doubt that the sensitiveness does in fact arise from
electrical waves coming from an approaching vessel, and not from electrical
waves which have been produced immediately before in close proximity to it.
These requirements are fulfilled by means of the rotating disc 11. So long as
the contact pieces 18 and 19 move beneath the contacts springs 20 and 21, no path
for the current exists over 26 and 27. As a result of this only the transmitting,
that is to say the starting apparatus, is operative.
Immediately however, connection is interrupted between the contact springs 20
and 21, all further production of sparks ceases, and this will take place owing
to the continuance of the rotation of the current breaker 6. Obviously the glass
tube 23 is still sensitive to the sparking which has been produced and the galva-
nometer relay 30 would act and kindle the lamp 39 if at the moment when the
production of sparks ceased the glass tube were not rendered non-sensitive.
The object is attained by means of the disc 11 which is provided with a third
path for a contact spring 40.and a contact piece 41.
The current from the battery 25 is conducted to the contact spring 40 through
the contact spring 26 over the projecting contact piece 19 and the contact piece 41
which is connected therewith. The further path of the current is through the
conductor 42, the electro magnet 43, the conductor 33 and the switch 34, in the
position 1, back to the battery. This path for the current is closed only for the brief
instant during which the contact piece 41 passes beneath the contact spring 40.

page_text: During this instant however the spring-mounted armature 44 of the electro
magnet 43 is attracted and the trembler 45 is displaced in the direction indicated
by the arrow 1 and comes in contact with a plate 46 which is connected with
the glass tube. Owing to the shock so produced the metal filings situated at 24
are displaced and consequently rendered non-sensitive, as is well known. If
they again become sensitive, whilst the contact pieces 18 and 19 maintain con-
nection between the springs 26 and 27, there can be no doubt that this result has
been produced by electrical waves proceeding from another vessel.
As soon as he perceives a signal, the navigating officer is certain that his own
transmitting apparatus has produced a signal upon the other vessel and it is
competent for both officers to consult telegraphically as to their respective courses
and upon other matters if desired, for which purpose it is arranged that the
switches 9 28 and 34 may be caused to occupy the position 11 by means of a
single handle.
The current breaker 6 continues to rotate; closing of the circuit for the primary
current of the transmitting apparatus is then effected by hand by means of the
Morse key 47, the Morse alphabet being employed to effect communication in the
usual manner.
Owing to the reversal, another battery 48 with reversed poles is inserted between
the switches 28 and 34, so that each time sensitiveness is produced the galva-
nometer relay 30 is traversed by a current in the opposite direction, and the
pointer produces contact between the contact springs 49 and 50, thereby render-
ing a Morse apparatus 51 operative; at the same time, however, the electro-
magnet 52 which is arranged in parallel with the Morse apparatus attracts the
armature 44 in the direction indicated by the arrow II and releases the glass
tube owing to its striking against the plate 46.
The cores of the electro-magnets 43 and 52 may be caused to approach nearer
to or recede from the spring-mounted armature by means of the set screws 54
and 55, thereby enabling the stroke of the trembler to be regulated in the desired
manner.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is
1. The warning and communicating device for vessels at sea based upon spark-
ing or wireless telegraphy by means of coherer and relay apparatus, characterised
by the fact that alternately with a sparking apparatus producing electrical waves,
and upon cutting out of the same, a receiver (coherer) is rendered operative the
connections being arranged in such a manner that the paths of the current both
of the transmitter and receiver pass over a rotating disc 11 which alternately
closes the path for the current between the contact spring 20 and 21 and 26
and 27 by means of their respective contact pieces 18 and 19, in combination with
a shunt to a preceding contact piece 41 for a sliding way for the spring 40 which
utilises the current of a source of electricity 25 between the termination of the
sparking and the commencement of the passage of the current passing through
the receiver 23 from the same source of electricity 25 for the actuation of the
galvanometer relay 30, for the purpose of causing an electro magnetic
trembler 44 45 to produce a shock upon the receiver 23, in order that when con-
ductability is produced upon the subsequent closing of the traversing current
no doubt may exist but that it is produced by means of electrical waves
proceeding from another vessel.
2. In a warning and communicating device for vessels at sea based upon spark-
ing or wireless telegraphy by means of coherer and relay apparatus, of the kind
described in Claim 1, the arrangement of the connections in such a manner that,
the whole of the paths for the currents pass over a current reversing arrangement
in three parts 9, 28 and 34, which, after a signal has been given, is reversed, so
that by using a Morse key telegraph communications may be exchanged by means

page_text: of the same device, for which purpose a source of current 48 is inserted between
the switches 28 and 34, the poles of which are arranged in the reverse manner to
those of the source of current 25 for the circuit of the position 1, for the purpose
of attracting the pointer of the galvanometer relay to the other side, that for
the Morse receiver apparatus.
3. In a warning and communicating device for vessels at sea based upon
sparking or wireless telegraphy by means of coherer and relay apparatus, of the
kind described in Claims 1 and 2, the employment of a double trembler 45, 53
capable of oscillating to both sides as armature common to two electro-magnets
adjustably arranged opposite one to the other.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicants.