Improvements in Telegraphic Instruments.
Year: 1887

page_text: Date of Application, 29th Nov., 1887
Specification Accepted, 30th Dec., 1887
Improvements in Telegraphic Instruments.
A communication from abroad by CHARLES GOODWIN BURKE, of Richmond Hill,
Queens County, State of New York, United States of America, Electrician.
I, WILLIAM PHILLIPS THOMPSON, F.C.S. M.I.M.E. of the Agency for Foreign
Patent Solicitors, 6 Lord Street, Liverpool, and 6 Bank Street, Manchester, both in
the County of Lancaster, and 323 High Holhorn, in the County of Middlesex, Civil
Engineer, 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 invention relates to the class of apparatus employed for receiving telegraph
signals, and its object is to provide a sensitive instrument capable of receiving and
repeating messages transmitted over long lines in which electric currents of small
power are used.
It is especially adapted for use with submarine cables where it is
required that the receiving instrument shall be very sensitive.
A coil or solenoid of insulated wire is placed in the circuit of the line and there is
provided for the solenoid an intense magnetic field consisting of two opposite
magnetic poles derived from one or more electromagnets. One of the poles of
the magnet encircles one end of the solenoid, while the other pole extends within the
other end of the solenoid. The two poles combine in their action to move the
solenoid in one direction or the other according to the character of the current
transmitted. The movements of the solenoid may be employed for operating a siphon
of the character usually employed in telegraphic cable systems, or they may operate a
circuit controlling device adapted to open and close the connections of an indepen-
dent circuit, and thus operate a recording instrument or sounder of any suitable
character.
Two solenoids are usually employed in a working instrument, each of which assists
the movements of the other.
In the accompanying drawings, figure 1 serves to illustrate the principles of the
invention figure 2 is a cross-section of the solenoid; figures 3 and 4 are respectively
an elevation and a plan view of a receiving instrument.

page_text: 7
In figures 1 and 2, L represents the main line which includes the coils of a
solenoid A. From these coils the line is continued to the earth at G. By securing
the main line at the points c¹ and c³ the solenoid is suspended in its proper position.
The electro-magnet B establishes a field of force for the solenoid. The magnet has
its two poles 61, 62, prolonged by the extensions e¹ and e². The extension e¹ is
expanded into the cup d¹ which extends over one end the solenoid, projecting nearly
to its center. The other polar projection e² passes within the solenoid from the
opposite end. The two coils 61 and 62 surrounding the core of the magnet B are wound
in the usual manner causing the two poles to be of opposite polarity, and the coils b₁
and are included in the circuit of the battery o. A current through the line L will
therefore cause the solenoid to swing toward the right hand or the left, depending
upon the direction of the current in the line L. The movements of the solenoid may
be employed for operating any of the usual devices for the purpose of using the
instrument as a receiver.
The application of the instrument will be described in connection with figures 3
and 4. In this instance two solenoids A1 and A2 are employed. These are carried
upon opposite arms of a pivoted lever F. The main line is connected by a
conductor with an insulated screw u' upon the lever or its axis, thence by a
conductor 2, through the coils of the solenoid A¹; thence by a conductor t³, either
with the lever, and thus with a conductor t, or directly with the latter; thence
through the coil A2, and through the conductor attached to a support u², and
thence to the outgoing section of the line L. These connections may of course be
variously modified.
The field magnets B1 and B2 are employed and they are included in the circuit of
the battery o. They are so wound and connected that the pole b₁ of the magnet B¹
will be of opposite polarity from the pole 6 of the magnet B². And likewise the
pole of the magnet B₁ is opposite in character from that pole b¹ of the same
imagnet and the pole 62 of the magnet B². The pole b₁ of the maguet B¹ is
constructed with a cup-shaped extension d' encircling the corresponding end of the
solenoid, while the pole enters within the other end. The pole 62 of the magnet B¹
passes within the coil A² and the extension d2 surrounds the other end of the same
coil. The cup-shaped extensions d¹ and d² are preferably integral with the respective
cores to which they are applied. The two coils A' and A² are included in the circuit
of the main line of the system to which the instrument is to be applied, and they
combine, when traversed by an electric current, to move the lever F in one direction
or the opposite. The movements of the lever thus occasioned are employed for
controlling the connections, in this instance, of an independent circuit derived from
a battery o¹. The connections of this battery are as follows:-From one pole, by
means of conductors 1 and 2, to two contact-points k¹ and k² applied to an arm or
extension n at one end of the lever F. This extension is in electrical connection
through the lever F with a conductor 3 attached to a suitable non-conducting
support, thence by a conductor 4, back to the battery. The conductor 3 is of
fine wire and is so arranged as not to interfere with the movements of the lever F.
When therefore the lever is actuated in one direction, it will close the circuit through
the conductor 13 when in the opposite direction it will close the circuit through the
conductor 2. Two instruments K' and K² are respectively included in these
conductors and one or the other will therefore be actuated according to the direction
of movement of the lever F. The instruments K₁ and K2 are employed for operating
receiving instruments or repeaters R' and R² (figure 4) in a manner well understood,
which need not here be described. Contact-points and may be applied to an
extension m carried at the opposite end of the lever F, and by having this extension
insulated from the extension n the connections of an independent circuit may be
controlled if desired. To guard against the accidental failure of good contacts being
made, it may in some instances be desired to connect the points and k² together,
and likewise the points ¹ and and have them co-operate with each other.
It should be observed that the lines of force are directed obliquely through the
solenoids. This is due to the fact that two poles of opposite character are presented

page_text: to opposite ends of the solenoids, and neither pole covers it completely, so that there
is a point of higher magnetic influence, with reference to each pole, than that
occupied by the solenoid when at rest, and therefore the solenoid when traversed by a
current of electricity, will move toward one pole or the other of the magnet,
according to the direction of the current and the consequent magnetic tendencies of
the solenoid.
In some instances it may be desirable that the movement of the lever F should
receive a slight steadying influence, and for this purpose the arms n and m are bent
downward as shown, and carry at their respective extremities small balls p¹ and p²,
which enter glycerine cups P1 and P². They are thus immersed in glycerine or
some other suitable fluid. This device is found to afford the required resistance to
the movement of the lever and give an even and reliable action. Such a device,
however, is not always essential.
Having now described the invention as communicated to me, I wish it to be
understood that what I desire to protect under letters patent is :-
1. In a telegraphic instrument, the combination of a solenoid capable of motion
longitudinally, and a magnet having one of its poles surrounding one end of the
solenoid, and the other pole entering the other end of the solenoid.
2. In a telegraphic instrument, a solenoid supported between two magnetic poles of
opposite character, one of said poles surrounding one end only of the solenoid, and
the other pole extending within the solenoid, whereby the lines of force are directed
obliquely through the coils of the solenoid.
3. In a telegraphic instrument, a solenoid suspended between the poles of a
magnet, one of said poles extending within the solenoid, and the other pole made
tubular and surrounding the other end of the solenoid, neither pole extending
beyond its center, and a recording device operated by the movements of the
solenoid.
4. In a telegraphic instrument, two solenoids upon a cominon support, each
solenoid having presented to its opposite ends, magnetic poles of opposite character,
one of which poles extends within the solenoid and the other pole surrounds the
same, and a recording device operated by the movements of the solenoids.
5. The telegraphic instrument described, consisting of the electro-magnets, the
solenoids, and the recording devices, the poles of the magnets being arranged to direct
only oblique lines of force through the solenoid coils.
Dated this 28th day of November 1887.
WM. P. THOMPSON & Co.,
Agents for the Applicant.