Improved Means for Transmitting Telegraphic Signals through Submarine and like Cables.
Year: 1893

page_text: Date of Application, 15th Feb., 1893
Complete Specification Left, 15th Nov., 1893-Accepted, 23rd Dec., 1893
PROVISIONAL SPECIFICATION.
Improved Means for Transmitting Telegraphic Signals through
Submarine and like Cables.
We, ALEXANDER MUIRHEAD, of No. 2 Prince's Street, in the City of West-
minster, Doctor of Science, and HENRY ALFRED CHARLES SAUNDERS, of
Winchester House, Old Broad Street, in the City of London, Electrician, do
hereby declare the nature of this invention to be as follows:-
The object of our invention is to effect improvements in the means of transmitting
signals through submarine and like telegraph cables especially with a view to
rendering the signals on long circuits clearer and more easily read.
In carrying out our invention we sometimes employ a curb key of novel con-
struction in combination with a polarised transmitter in place of the ordinary
well-known hand signalling key or automatic instrument with perforated paper
which is now used, the curb key being so designed that the battery is applied to the
cable in an interval as short as possible after the movement of one or other of the
levers of the key, and at the end of every stroke or movement of either lever
the reverse pole of the battery is kept applied to the cable during the period of
the return stroke or movement. By such an arrangement of the levers the
intervals between the cable and battery contacts and earth contact can be reduced
to the shortest possible amount, the result being the production of clearer and
more sharply defined signals.
The polarised transmitter used for the purposes of this invention may consist of
a double-tongued polarised relay such as described in the Specification of Letters
Patent No. 4,590 of 1878 and illustrated at Figures 6 and 7 in the drawing
accompanying such Specification.
.
A modified form of transmitter devised by us for this invention consists of two
electro-magnets one of which is connected with the left hand or "dot" contact
maker of the key or automatic transmitter and the other with the right hand or
"dash"
contact inaker of the key or automatic transmitter. These electro-magnets
each control an armature which is pivotted at one end and works between adjustable
stops near the other. Attached to the free ends of each of these armatures is a
contact-making arm which extends out from the armature at, or nearly approaching,
a right angle. The outer end of this arm is platinised on both sides and the arm
may be made either rigid (which we prefer) or flexible. If a rigid arm is used, its
free end is caused to play between a pair of platinised springs so as to make good
prolonged rubbing contact therewith during its movement, the position of the ends
of the springs being adjustable by means of screws, so as to be capable of being
set at will more or less into the path of motion of the contact-arm. Or if a flexible
arm is used it is caused to play between a pair of adjustable screw stops, tipped
with platinum and placed opposite to the platinum contacts on the arm.
either case, however, in consequence of the angle at which the contact-arm is
set with relation to the armature, a good prolonged rubbing contact is made
with the side springs or stops for each movement of the arm, and the relative
duration of the current or earthing contacts can be so regulated as to give
the best results in regard to the length of the cable. The contact-arms and
side springs or stops are so connected that when one of the armatures is
attracted by the passing of a current round the coils of its electro-magnet
from the left-hand side of the key or automatic transmitter, a current in one
direction is put into the cable and when the other armature is attracted by
passing a current from the right-hand side of the key or automatic transmitter a
current in the opposite direction is put into the cable producing right and left-hand
In

page_text: deflections at the receiving end of euch cable of more uniform duration than when
a hand key or automatic transmitter only is used. We sometimes polarise the
electro-magnets in the transmitter after the manner of the well-known Siemens
relay. The action of the transmitter may be retarded, if necessary, by means of
a magnetic shunt on the coils of the electro-magnets or by a dash-pot" or
equivalent device attached to the contact-arms.
66
In the accompanying drawings Figure 1 illustrates diagrammatically the essential
parts of the combination above referred to.
P, P, is the double polarised transmitter in the local circuit of which are formed
the contacts with the main or line battery, B₁, the condenser, S₁, in connection
with the cable, and the earth.
K, represents the curbing device or key we have designed for the purpose of this
invention. Li, L., are the two levers of the key which can be actuated either by
hand or by the automatic key hereinafter described. The lever, L₁, is made in two
parts,, and, y, of conducting material insulated from each other by means of a
piece of ebonite or its equivalent, m. The lever, L., is made in one piece of
conducting material terminated by a piece of ebonite or its equivalent, n. The
levers, Li, and, L, are pivotted at one end and their opposite ends are adapted to
move loosely between projections in the sliding pieces, w, w, pushing the latter
backwards and forwards into contact with the spring-contacts, v₁,,, and ., .
The sliding piece w₁, is electrically connected with the, y, end of lever, L1,
and, w, is electrically connected with the contact block, b. B,, is a split battery.
The contacts, b1, bg, v₁, v, v, and, v., are electrically connected to various parts of
the key as shown in the diagram.
:-
"
When the levers, L₁, and, L., are at rest on the stops, a₁, a, the sliding pieces, 101,
and, w,, rest on the stops, v., and, v, respectively. To explain the action of the
key When, say, lever, L₁, is depressed or moved to the left, L₁, leaves, a₁, and
immediately comes into contact with, b₁, remaining in contact therewith till it has
reached the limit of its movement when the sliding piece, ₁, is pushed from the
stop, v, and put into connection with the stop, v1. The result of this movement of
the lever, L₁, is first of all to disconnect, x, from, a₁, and to put the zinc pole, Z, of
the battery, B., to one end of the circuit of the coils of the transmitter, P, P, the
middle of the battery being already in connection with the other end of the circuit.
A current in a certain direction flows through the polarised transmitter coils
deflecting one of the two tongues, t₁, t, thereby applying one pole of the main
line battery, B₁, to the condenser, S₁, and the cable. Afterwards, when the
sliding piece, w₁, is put in contact with, r, the battery, B., is reversed and a
current in the opposite direction is passed through the coils of the double trans-
mitter, P, P, causing the other tongue to be deflected, thereby connecting the
opposite pole of the battery, B₁, to the condenser, S₁, and the cable. This
latter state of things continues until the lever, L₁, has returned to its position
of rest on the stop, a,, when the cable and condenser, S₁, become disconnected
from the battery and put to earth through the tongues, t₁, t,, and the back stops
of the transmitter.
Instead of the curb key, K, we sometimes employ an automatic key of novel
construction together with a split battery joined up in connection with the coils
of the polarised transmitter or double-tongued relay and a condenser, in such
manner that the charge and discharge of the condenser effect the same move-
ments of the tongues of the transmitter as is effected by the curb key. The
duration and the strength of the condenser charges are regulated by means of
suitable resistances.
Figure 2 of the accompanying drawings shows the essential parts of the
apparatus which we have designed for this mode of carrying out our invention.
A, A, is the automatic key consisting of two levers, L₁, and, L., which complete
the local circuit of the polarised transmitter through the bridge contact-piece, Y.
These levers are connected respectively with the two poles of the split-battery, B,
through adjustable resistances, r,, T. In series with the coils of the double

page_text: polarised transmitter, P, P, are connected the condenser, S,, shunted with an
adjustable resistance, r, the split battery, B, and the automatic key, A, A.
The automatic key, A, A, may be operated either by hand like an ordinary cable
key or by means of a band of perforated paper, R, as in the well-known Wheatstone
Automatic Transmitter which is used in fast speed telegraphy on land lines.
The levers are adjusted to complete the battery circuit through the bridge-
piece, Y, and to break the same whenever a hole in the perforated band, R, passes
under one or other of the levers. In the roller, X, over which the perforated band
passes, are two circular grooves, g,g, into which the levers, Li, L., can fall.
Sometimes we may use the hereinbefore mentioned curb key, or the automatic
key in the manner above described, in direct connection with the cable and not in
combination with the polarised transmitter.
Dated thie 15th day of February 1802
A. F. SPOONER,
124, Chancery Lane, W.C., Agent for the Applicants.
COMPLETE SPECIFICATION.
Improved Means for Transmitting Telegraphic Signals through
Submarine and like Cables.
We, ALEXANDER MUIRHEAD, of No. 2 Prince's Street, in the City of
Westminster, Doctor of Science, and HENRY ALFRED CHARLES SAUNDERS, of
Winchester House, Old Broad Street, in the City of London, 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 object of our invention is to effect improvements in the means of transmitting
signals through submarine and like telegraph cables especially with a view to
rendering the signals on long circuits clearer and more easily read.
In carrying out our invention we sometimes employ a curb key of novel
construction in combination with a polarised transmitter in place of the ordinary
well-known hand signalling key or automatic instrument with perforated paper
which is now used, the curb key being so designed that the battery is applied to
the cable in an interval as short as possible after the movement of one or other of
the levers of the key, and at the end of every stroke or movement of either
lever the reverse pole of the battery is kept applied to the cable during the period
of the return stroke or movement. By such an arrangement of the levers the
intervals between the cable and battery contacts and earth contact can be reduced
to the shortest possible amount, the result being the production of clearer or more
sharply defined signals.
The polarised transmitter used for the purposes of this invention may consist of
a double-tongued polarised relay such as described in the Specification of Letters
Patent No. 4,590 of 1878 and illustrated at Figures 6 and 7 in the drawing
accompanying such Specification.
"
"
A modified form of transmitter devised by us for this invention consists of two
electro-magnets one of which is connected with the left hand or "dot contact
maker of the key or automatic transmitter and the other with the right hand or
"dash
contact maker of the same key or automatic transmitter. These electro-
magnets each control an armature which is pivotted at one end and works between
adjustable stops near the other. Attached to the free ends of each of these
armatures is a contact making arm which extends out from the armature at, or
nearly approaching, a right angle. The outer end of this arm is plutinised on both
sides and the arm may be made either rigid (which we prefer) or flexible. If a
rigid arm is used its free end is caused to play between a pair of platinised springs
so as to make good prolonged rubbing contact therewith during its movement, the
position of the ends of the springs being adjustable by means of screws, so as to
be capable of being set at will more or less into the path of motion of the contact-

page_text: arm. Or if a flexible arm is used it is caused to play between a pair of adjustable
screw-stops, tipped with platinum and placed opposite the platinum contacts on the
arm. In either case, however, in consequence of the angle at which the contact
arm is set with relation to the armature, a good prolonged rubbing contact is made
with the side springs or stops for each movement of the arm, and the relative
duration of the current or earthing contacts can be so regulated as to give the best
results in regard to the length of the cable. The contact arms and side springs
or stops are so connected that when one of the armatures is attracted by the
passing of a current round the coils of its electro magnet from the left hand side
of the key or automatic transmitter, a current in one direction is sent into the
cable and when the other armature is attracted by passing a current from the
right-hand side of the key or automatic transmitter a current in the opposite
direction is sent into the cable producing right and left hand deflections at the
receiving end of such cable of more uniform duration than when a hand key or
automatic transmitter only is used. We sometimes polarise the electro-magnets
in the transmitter after the manner of the well-known Siemens relay. The action
of the transmitter may be retarded if necessary, by means of a magnetic shunt on the
coils of the electro-magnets or by a "dash pot" or equivalent device attached to
the contact arms.
Figure 1 of the drawings accompanying our Provisional Specification illustrates
diagrammatically the essential parts of the combination above referred to.
P, P is the double polarised transmitter in the local circuit of which are formed
the contacts with the main or line battery B', the condenser S¹, in connection with
the cable, and the earth. K represents the curbing device or key we have designed
for the purpose of this invention. L', L' are the two levers of the key which can
be actuated either by hand or by the automatic key hereinafter described. The
lever L' is in two parts x and y of conducting material insulated from each other
by means of a piece of ebonite or its equivalent m. The lever L' is made in one
piece of conducting material terminated by a piece of ebonite or its equivalent n.
The levers L and L' are pivotted at one end and their opposite ends are adapted
to move loosely between projections in the sliding pieces w¹, w' pushing the latter
backwards and forwards into contact with the spring-contacts v', 1, and
The sliding piece wol is electrically connected with the y end of lever L', and w³ is
electrically connected with the contact block 6. B is a split battery. The
contacts 6, 62, v1, v2, v3 and v³ are electrically connected to various parts of the key
as shown in the diagram.
v³.
When the levers L' and L' are at rest on the stops a', a³ the sliding pieces 10¹
and wrest on the stops and respectively. To explain the action of the
key; When, say, lever L is depressed or moved to the left, L¹ leaves a¹ and
immediately comes into contact with ', remaining in contact therewith till it has
reached the limit of its movement when the sliding piece w', is pushed from the
stop and put into connection with the stop ¹. The result of this movement of
the lever L is first of all to disconnect a from a' and to put the zinc pole Z of
the battery B to one end of the circuit of the coils of the transmitter P, P the
middle of the battery being already in connection with the other end of the circuit.
A current in a certain direction flows through the polarised transmitter coils
deflecting one of the two tongues t¹, thereby applying one pole of the main line
battery B to the condenser S' and the cable. Afterwards, when the sliding
piece w¹ is put in contact with ', the battery B is reversed and a current in the
opposite direction is passed through the coils of the double transmitter P, P causing
the other tongue to be deflected thereby connecting the opposite pole of the
battery B' to the condenser S' and the cable. This latter state of things continues
until the lever L' has returned to its position of rest on the stop a' when the cable
and condenser S¹ becomes disconnected from the battery and put to earth through
the tongues t, and the back stops of the transmitter.
The drawing accompanying this Specification is illustrative of a modified form
of curbing device or key which we may use in lieu of that hereinbefore described.

page_text: Referring to this figure the levers L', L' are pivotted at p. p and carry
extensions to, to each of which oscillate between two stops v¹, and v¹ and ³
respectively. Ebonite or equivalent studs m, m attached to the levers normally
bear on spring contacts s', 82, these latter, on the levers being operated, falling on
to limiting stops *, . The contacts v³, v³, v, and the other parts of the
apparatus are electrically connected to the split battery as shown. When the
levers L¹, L' are at rest on the stops a', a' the extensions w¹, rest on
the stops v', '. Upon, say, lever L' being depressed, it leaves the contact a' and
the extension to immediately comes in contact with remaining in contact there-
with till the lever has reached the limit of its movement when the spring s falls
into contact with the limiting stop v. The result of this movement of the lever
is first of all to disconnect the extension to from the contact and to put the
copper pole of the battery B2 to the lever L' which is connected to one end of
the circuit of the coils of the transmitter P, P (Figs. 1 and 2) the middle of
the battery being already in connection with the other end of the circuit. After-
wards on the lever rising wis put in contact with and the zinc pole of the
battery B is applied through and the spring contact s¹ to L' and a current in
the opposite direction is passed through the coils of the double transmitter P, P
causing the other tongue to be deflected giving the requisite curbing current.
This latter state of things continues until the lever L' has returned to its position
of rest on the stop al.
Opposite electrical changes take place when the lever L' is operated.
Instead of the curb keys hereinbefore described we sometimes employ an
automatic key of novel construction together with a split battery joined up in
connection with the coils of the polarised transmitter or double-tongued relay and
a condenser in such manner that the charge and discharge of the condenser effect
the same movements of the tongues of the transmitter as is effected by the curb
key. The duration and the strength of the condenser charges are regulated by
means of suitable resistances.
Fig. 2 of the drawings accompanying our Provisional Specification shows the
essential parts of the apparatus which we have designed for this mode of carrying
out our invention.
A, A is the automatic key consisting of two levers L1, L2 which complete the
local circuit of the polarised transmitter through the bridge contact piece Y.
These levers are connected respectively with the two poles of the split battery B'
through adjustable resistances
In series with the coils of the double
polarised transmitter P, P are connected the condenser S shunted with an adjust-
able resistance, the split battery B³, and the automatic key A, A.
The automatic key A, A may be operated either by hand like an ordinary cable
key or by means of a band of perforated paper R as in the well known Wheatstone
Automatic Transmitter which is used in fast speed telegraphy on land lines.
The levers are adjusted to complete the battery circuit through the bridge
piece Y and to break the same whenever a hole in the perforated band R passes
under one or other of the levers. In the roller X over which the perforated band
passes are two circumferential grooves g, g into which the levers L', L' can fall.
It will be seen that on ope or other of the levers L', L' leaving its limiting stop
a current begins to flow through the polarised transmitter and is kept flowing until
the lever returns to the stop, the result being an instant application of the signalling
battery to the cable.
Sometimes we may use the hereinbefore mentioned curb keys or the automatic
key in the manner described in direct connection with the cable and not in com-
bination with the polarised transmitter.
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 curb key so constructed that immediately on the movement of one or

page_text: other of its levers the battery is applied to cable and at the end of every such
stroke or movement the reverse pole of the battery is kept applied to cable during
the period of the return of the lever to its position of rest substantially as set
forth.
2. The automatic key so constructed that upon one or other of its levers leaving
its limiting stop the battery circuit is broken and remains broken till such lever
returns to its position of rest substantially as and for the purpose set forth.
3. The combination, in a system of transmission of signals through submarine
and like cables, of the curb keys or an automatic transmitter constructed as herein
described with double polarised transmitters substantially as and for the purpose
set forth.
4. In a system of transmission of signals through submarine and like cables, the
means, substantially as set forth, whereby the currents sent into the cable are
caused to flow from the instant the contact levers of the transmitter leave their
respective limiting stops, such currents continuing till the levers return to their
position of rest.
Dated the 15th der of November 1802
A. F. SPOONER,
124, Chancery Lane, W.C., Agent for the Applicants.