Improvements in or in connection with Long Distance- Telephones.
Year: 1894

page_text: Date of Application, 28th June, 1894-Accepted, 18th Aug. 1894
COMTIMIN E MULTTU
Improvements in or in connection with Long Distance-
Telephones.
I, WASILI ALEXANDROWICZ NIKOLAJCZUK of Kiew in the Empire of Russia,
Electrician, 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 :-
The present invention has for its object to enable telephonic communication to
be held over very great distances.
This object is effected according to this invention by periodic currents which are
produced in the transmitter and cause a variation of the current strength of a
source of current by means of a peculiarly arranged device (termed liquid-rheostal)
which is situated in an exchange station and is conductively connected with the
receiver. The currents produced by varying the resistance in the auxiliary current
source are then converted by the receiver periodically and according to the
transmitter currents into sound waves.
The invention is illustrated in the accompanying drawings in which :-
Figs. 1 and 3 illustrate the apparatus at two stations the connecting line or
circuit between which is interrupted by an apparatus illustrated in Fig. 2.
The apparatus a (Fig. 1) is connected by a line be with a bobbin d which may
be advantageously surrounded by an iron shell or casing d₁ for increasing the
sensitiveness of the apparatus illustrated in Fig. 2.
In this solenoid there is arranged so as to be freely movable therein a cylindrical
magnet rode which transmits the vibratory motion that it receives from the currents
passing through the coil by means of a spindle fto a flat or leaf spring fixed to
the metal block g.
The spring i in turn imparts a vibratory motion to an electrode k which is
arranged on the free end of the spring and is composed of platinum or other suitable
material.
The active portion of the electrode is capable of being adjusted longitudinally by
means of a set screw n. This electrode k dips into a vessel M' which is filled with
acidulated water and opposite this electrode there is another electrode / fixed in
the vessel M¹.
One pole of the battery B is conductively connected with the spring i and
consequently also with the electrode k whilst the other pole of the battery is
conductively connected with the electrode l.
The last-mentioned circuit has included in it an induction coil which is
surrounded by a secondary coil. The latter is connected by a linest with the
receiver 2.
The mode of operation is as follows:-
The periodic current produced in the circuit bc by speaking into the apparatus a
impart in flowing through the coil d vibratory motion to this extremely sensitive
magnet whereby the electrode k will be caused to move nearer to or away from the
electrode in accordance with the said vibratory motion.
The result of this is to produce powerful variations of current of the battery B
which is only very slightly brought into requisition whilst the electrode k is
at rest.
These variations of current produce inducted currents in the aforesaid coil
which are converted in the apparatusz (Fig. 3) into sound waves in an effective
manner.

page_text: Of course this arrangement may be replaced by any other equivalent arrangement
acting on the same principle so long as the object in view is effected.
When the distances between two stations are considerable then a number of
intermediate stations may be arranged according to the circumstances of each case
and I do not limit myself to the position of any such station which are constructed
as above described and all operate in the same manner.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. The method of increasing the strength of the sound waves produced in the
receiver of a telephone consisting in periodic currents which are produced in the
transmitter causing a variation of the current strength of any source of current in
such manner that currents pass out from said source which are synchronous with
and directly proportional to the aforesaid periodic currents and are then converted
into sound waves in a receiver substantially as and for the purposes herein before
described.
2. For carrying out the method specified in Claim 1,-I claim an apparatus con-
sisting of a solenoid in which a variable magnetic field is produced by the periodic
currents produced in the transmitter flowing through the coils of the solenoid a
magnet suitably arranged within the said solenoid vibrated by said variable
magnetic field and the electrodes of a source of current adapted to be acted upon
by the said vibrations from said magnet substantially in the manner and for the
purpose hereinbefore described.
3. The apparatus arranged constructed combined and acting substantially in the
manner and for the purposes herein before described and illustrated in the drawings
hereunto annexed.
Dated this 28th dor of Tune 1904
TONGUE & BIRKBECK,
34, Southampton Buildings, Chancery Lane, London, W.C.,
Agents for the Applicant.