Improvements relating to the Transmission and Reception of Telegraphic Signals and to Apparatus therefor.
Year: 1889

page_text: Date of Application, 19th Nov., 18891
Complete Specification Left, 16th Aug., 1890-Accepted, 4th Oct.,.1890
PROVISIONAL SPECIFICATION.
[Communicated from abroad by STEPHEN D. FIELD, of Stockbridge, in the County
of Berkshire, State of Massachusetts, United States of America, Electrical
Engineer.]
Improvements relating to the Transmission and Reception of
Telegraphic Signals and to Apparatus therefor.
I HENRY HARRIS LAKE, of the firm of Haseltine Lake and Co. Patent Agents,
Southampton Buildings, in the County of Middlesex, do hereby declare the nature of
this invention to be as follows:-
This invention relates to the construction and arrangement of apparatus for
sending and receiving telegraphic signals through submarine cables.
It is a well known fact that in an insulated underground or submarine cable the
high specific inductive capacity of the material used for insulation gives a corre-
sponding high static capacity and the energy of the signalling current or impulses is
largely transformed into static charge, and the signals retarded and confused
accordingly. The transmission of telegraphic signals over such cables is accomplished
at a very slow rate and with great difficulty, and it has hitherto been found
impracticable in respect of speed to use the Morse method (involving relay contacts
and local batteries and sounders) on cables more than one thousand miles in
length.
The object of my invention is to provide apparatus of such mode of operation and
delicacy of action as will admit of ordinary Morse transmission over a cable of any
length usually existing.
The invention comprises a system of telegraphy embracing the sending apparatus
or key, and receiving apparatus or relay.
The qualifications of a good key for submarine cable work are :-Upon depression
it must allow a certain amount of current to flow through the cable, and then
immediately cut off the supply of current and place that end of the cable to earth for
static discharge, so that a prolonged depression of the key cannot keep current flowing
through the cable and so produce an abnormal static charge therein. Upon release,
the key must again momentarily admit current to the cable, but in an opposite
direction to that flowing upon depression, and then immediately place that end of the
cable to earth. The result should therefore be that the cable is placed to earth (or
through the receiving apparatus at that end and thence to earth) at all times except
the very short spaces of time corresponding to the first part of the movements of
depression and release, when the signalling current is admitted, but in alternate
directions, in the cable."
The receiving apparatus should be of so delicate a nature as to respond to minute
variations of polarity in the cable and transform these into vigorous mechanical
movement of the relay tongue, to effectively utilize the Morse system of
transmission..
The sending apparatus comprise the following:-
An operating key is made part of a local circuit, which includes an electro-magnet
and a battery. The opening and closing of this key causes the magnet to attract and
release an armature which is mounted on a pivoted lever, one end of which operates a
pole-changing key having continuity-preserving contacts which control the action of
the line or cable battery. The other end of the pivoted lever at the limits of its
movement closes a local circuit, which includes another electro-magnet and a battery
therefor, but at points between the limits of its movement the latter circuit is open.
The armature of the second electro-magnet is carried on a pivoted lever which operates
a switch which in one position grounds the cable and in the other position closes the

page_text: cable battery on to the cable. Owing to the fact that the first pivoted lever has a
range of movement between its stops, during which the circuit of the second electro-
magnet is open, it follows that the operation of the main key will be of the required
character; namely, that upon depression a certain amount of current momentarily
flows through the cable and then is immediately cut off and the cable grounded for
static discharge, and on the release of the operating key current is again momentarily
admitted to the cable but in an opposite direction, and then immediately the cable is
again grounded. There is, therefore, no chance for the errors of "personal equation
in attempting to judge the proper interval of time in admitting current to the cable,
because a regular and determinate amount of current flows in the cable for each signal
and indicates the beginning and end only of such signal corresponding to the make
and break of the Morse system.
"
In some cases it is desirable to have the first of these two signals i.e. the make, a
trifle longer than the second i.e. the break. This may be accomplished by a skilful
adjustment of the pole-changer contacts. but I prefer to arrange it otherwise by
placing on the first pivoted lever a small momentum contact controlled by a spring
arranged so that when the said lever is attracted by its magnet the momentum contact
is, by the sudden stop of the lever, thrown away slightly and thus the period of break
in the second local circuit is slightly prolonged.
The receiving apparatus is of the following character:-I construct an "iron-clad'
magnet, which may be either permanent or electro, and in the latter case energized by
a suitable local battery. This magnet is arranged to have two similarly polarized cores
and a surrounding shell of opposite polarity, thus producing two annular fields of force. In
these fields of force I suspend two fine coils so wound that the arriving currents circulate
therein in reverse directions. These coils are carried by a light aluminium frame sus-
pendent, partly by a silk fibre and partly by a torsion wire, to a suitable capstain screw.
The end of the cable terminates in the capstain screw, whence the work passes through the
torsion wire and by a light connection to the fine wire coils carried by the frame, and
thence into a mercury cup into which the frame dips and from there to earth. The
frame carries a cross bar which is placed in light contact on each side with corre-
sponding spring-retracted levers, which in the opposite direction are held by very thin
wires whose distant ends are connected to tension regulating screws. These wires I
term thermic expansion wires. Each of them forms part of a separate circuit which
includes a battery and corresponding coils, which are wound on the cores of a polarized
relay, the arrangement being such that when the cross bar on the light-aluminium_
frame is bearing with equal pressure on the small pivoted. levers the strength of the
two local batteries is exactly balanced on the polarized relay and the latter is inert.
When, now, an impulse arrives over the cable it disturbs the position of the fine wire
coils situated in the two annular fields of force and thus more or less changes the
pressure of the ends of the cross bar against the pivoted levers which form the
terminals of the two thermic expansion wires. The equal amount of heat generated
in these two wires by the respective batteries is at once changed by the movement of
the cross-bar. The result is that one of these wires becomes more or less cool and
the other more or less heated, with a resultant change in the amount of current
flowing through the two normally balanced circuits of the polarized relay, and at once
the tongue of the latter is shifted. A local circuit for this relay is applied in the
usual manner and includes a local battery and an ordinary Morse sounder. Accordingly
therefore the successive impulses of currents arriving over the cable have the effect
of differentiating the resistance of the circuits which include the tberinic expansion
wires and therefore differentiating the amount of current flowing in the two normally
balanced local circuits of the polarized relay, which accordingly shifts from one
position to the other and thus gives a vigorous and reliable movement for the operation
of a local sounder, so that the signals may be received according to the ordinary
Morse system of telegraphy.

page_text: COMPLETE SPECIFICATION.
Improvements relating to the Transmission and Reception of
Telegraphic Signals and to Apparatus therefor.
I, HENRY HARRIS LAKE, of the firm of Haseltine, Lake & Co., Patent Agents
45 Southampton Buildings in the County of Middlesex, 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:-
This invention relates to the construction and arrangement of apparatus for sending
and receiving telegraphic signals through submarine cables.
It is a well known fact that in an insulated underground or submarine cable the
high specific inductive capacity of the material used for insulation gives a corre-
sponding high static capacity and the energy of the signalling current or impulses is
largely transformed into static charge, and the signals retarded and confused
accordingly. The transmission of telegraphic signals over such cables is accomplished
at a very slow rate and with great difficulty, and it has hitherto been found imprac-
ticable in respect of speed to use the Morse method (involving relay contacts and
local batteries and sounders) on cables more than one thousand miles in length.
The object of my invention is to provide apparatus of such mode of operation and
delicacy of action as will admit of ordinary Morse transmission over a cable of any
length usually existing.
The invention comprises a system of telegraphy embracing the sending apparatus
or key, and receiving apparatus or relay.
The qualifications of a good key for submarine cable work are:-Upon depression
it must allow a certain amount of current to flow through the cable, and then imme-
diately cut off the supply of current and place that end of the cable to earth for
static discharge, so that a prolonged depression of the key cannot keep current
flowing through the cable and so produce an abnormal static charge therein. Upon
release, the key must again momentarily admit current to the cable, hut in an opposite
direction to that flowing upon depression, and then immediately place that end of the
cable to earth. The result should therefore be that the cable is placed to earth (or
'through the receiving apparatus at that end and thence to earth) at all times except
the very short spaces of time corresponding to the first part of the movements of
depression and release, when the signalling current is admitted, but in alternate
directions, in the cable.
The receiving apparatus should be of so delicate a nature as to respond to minute
variations of polarity in the cable and transform these into vigorous mechanical
movement of the relay tongue, to effectively utilize the Morse system of transmission.
In the description of the drawings similar letters of reference are used to denote
similar or comparable parts. In sheet 1, Fig. 1 illustrates diagrammatically a
transmitting or sending apparatus and its circuit connections for operating in
accordance with my invention; sheet 1, Fig. 2 illustrates an attachment secured
to the lever which operates the pole-changing apparatus for prolonging the impulse
transmitted to the cable when it is desired that such impulse shall be of greater
duration on the make of contact at the key than on the break thereof; sheet 2,
Fig. 3 illustrates diagrammatically the receiving apparatus and its circuit connections
at the receiving end of the cable.
The operator's transmitting key 1 is included in a local circuit containing a local
battery 3 and a magnet 2. The opening and closing of this key charges and
demagnetizes magnet 2 which operates upon armature lever 4. This armature lever
controls two circuits, one being a local circuit including the local battery 12 and
electro-magnet 13, and the other being the circuit of the cable charging battery 9,
the poles of which may be reversed with respect to the cable line, by means of
the pole changing levers 67 operated by the right end 5 of the lever 4. Magnet 13
is energized at all times except when the lever 4 changes its position with reference
to the two co-operating contacts 10 11, when for a moment it will be demagnetized

page_text: and permit armature 14 to be retracted by its retractile spring. The armature
levers 4 and 14 are both connected with ground 20, as indicated in the drawing.
One end of armature lever 14 co-operates with a switch or circuit-closing lever 15
in such a way that when the magnet 13 is energized the cable 18 will be connected
to ground through the lever 14 at the transmitting station; but when the magnet 13
is de-energized the change of position of the lever 14 permits contact of the lever 15
with stop 16 and forces the line battery 9 into connection with the cable. It
results from this organization that the battery 9 will throw current into the cable
for a definite fixed time, irrespective of the length of time the operator may hold
his key 1 closed or opened, inasmuch as such current can pass to line only during
the sweep of the armature lever 4 between its stops 10 11. At all other times
the magnet 13 will be energized and the cable will be grounded through switch-
lever 15 and wire 10'. Upon the closure of the operator's key an impulse of current
of different polarity enters the cable from that which enters upon the opening of
the key; or, in other words, the charging battery 9 has its connections reversed
with reference to the cable. This result is due to the pole-changing key shown
at 5 6 7 and 8 in Fig. 1. The operator's key 1 being closed and the magnet 2
excited armature lever 4 will have its end 5 lifted vertically so as to bring the
contact it carries into electric connection with a co-operating contact on lever 6,
which is connected with the copper pole of battery 9. Simultaneously therewith
the levers 7 follows the lever 5 until an intermediate contact engages with a corre-
sponding contact mounted on a fixed anvil block 8, this block being electrically
connected with an anvil 16 co-operating with a contact on the lever 15. The two
poles of the battery 9 are connected with the pivotal points of the levers 6 and 7,
and the pivotal point of lever 15 is connected with the end of the cable. The
contacts of the levers 5 6 7 and block 8 are so adjusted that the poles of the
battery will be reversed without any rupture of the circuit, thus constituting a
continuity preserving device, the structure of which is well understood in the art.
As illustrated in Fig. 1 the zinc pole of the battery 9 has just been connected
with the cable, but inasmuch as the armature lever 4 bas completed its stroke the
local circuit 12 is closed at contact 11, and armature lever 14 drawn to its
magnet 13, thus disconnecting the connection of anvil 16 with the cable and
completing a ground for the latter through the lever 14 and wire 10. A negative
impulse has therefore been transmitted to the distant cable station and the-ground
connection made for the static discharge. It will therefore be seen that owing to
the fact that the armature lever 4 closes a local circuit 12 at both its forward and
backward contact stop and opens the local circuit only while it is in transit from
one stop to the other that the necessary conditions for successful cable transmission
herein before recited are made; that is to say, upon depression of the key a certain
amount of current momentarily passes through the cable and is then cut off and the
cable grounded for static discharge, and on release of the operating key current of
an opposite polarity is momentarily admitted to the cable and the latter again
grounded for the discharge of the static effect due to said current. There is there-
fore no chance for the errors of personal equation of individual operators, tending
to result in confusing differences of time during which current is admitted to the
cable; since irrespective of the length of time the operator may hold his key opened
or closed a regular and determined amount of current flows into the cable for each
signal and indicates the beginning and end of the signal corresponding to the make
and break in the Morse system.
In some cases it is desirable to have the first of the two parts. of a signal, namely,
the make, a trifle longer than the second, namely, the break. This may be accom-
plished by a skilful adjustment of the pole-changing contacts on the levers 6 and. 7
in Fig. 1, but I prefer to accomplish it by the device shown in Fig. 2. Secured to
the lever 4 on its under side is a spring carrying an. auxiliary contact 21 co-operating
with a contact on the same anvil with that which co-operates with contact 11.
When the key is closed and the armature 2 is magnetized lever 4 is forcibly drawn
downward, inaking contact at 11 and breaking contact at 10, but the weight of

page_text: contact 21 acquires sufficient momentum, by reason of this movement, to rupture its
contact with its co-operating anvil, and thus the circuit which can only be completed
through the lever 4 is held open automatically until the contact 21 can return to its
normal position and complete the circuit by bearing in engagement with its anvil.
In this way the circuit of the local battery 12 will be held open when the operator'is
closing his key for a longer time than it will be when he opens his key, and the
length of time during which the lever 14 will be retracted, or, in other words, the
length of time in which the battery 9 can discharge into the cable, will be longer for
'the make of the sending key than it will be for the break. Of course in retracting
armature lever 4 the weight 21 also acquires momentum, but inasmuch as it is
normally held by its spring in contact with its anvil the upward tendency only makes
- a firmer contact and does not affect the time of demagnetization of magnet 13.
My receiving apparatus, illustrated in Fig. 3, is very delicate of operation, and
comprises a differential relay, shown in the lower part of the figure, current in one
of the circuits of which is varied in strength by the instrument illustrated in the top
portion of the figure. The latter comprises an iron-clad magnet 24 which may be
either permanently magnetized or may be an electro-magnet, and consists of a hollow
outside portion of magnetic material and two central cores 25 25 homogeneous with
tor magnetically connected with the outer part 24 at the rear end. This magnet pro-
duces an annular field of force at its open end, lines of force proceeding from the
cores 25 25 to the end of the enclosing shell, the ends of the cores 25 being of one
and the same polarity, and the end of the shell being of opposite polarity. In front
of the iron-clad magnet is suspended two fine coils of wire 26 27 wound in opposite
directions and connected together, the two free terminals being connected respectively
with a light aluminium frame 28 and by a flexible metallic connection with a
suspending wire by which the aluminium frame is supported from a torsion adjusting
button 23. The lower portion of the aluminium frame dips in a mercury cup 37
and its upper portion is supported by a fine thread of silk fibre connected with a
torsion wire depending from the adjusting stud 23. On the upper part of the frame
are mounted two contact arms 29 30 adapted to co-operate with the ends of two
spring actuated contact levers 31 32, said levers holding under tension two German
silver wires 33 34 connected with adjusting buttons 35 36, both these buttons having
common connection with ground. Two differential coils 40 41 of the polarized
relay are connected respectively in circuit with batteries 38 39, and by means of
conductors 43 42 connect with the pivotal points of levers 32 31. When the apparatus
is in its normal position current from the batteries 38 39, which are of equal strength,
exerts equal and opposing effects on the cores of the relay, said current passing
through conductors 43 and 42 and wires 34 and 33. These wires 34 and 33 are
warmed or heated by the passage of the current, but as both are affected alike the
polarized relay remains inactive; but when a current proceeds through the cable and
circulates in the flat coils. 26.27 and thence by way of the aluminium frame and
mercury cup to ground, an angular deviation of the frame is created inasmuch as the
coils 26 27 are reversely wound and one is repelled by and the other attracted toward
the field of force of the iron-clad magnet. The angular variation produces a contact
with one of the levers 31.32, the co-operating edges of the levers and arms being pro-
vided with iridium or other inoxidizable contact points, and thereby shunts a portion
of the current from one of the wires 42 43 to the wire 47, producing a difference in
the heating effect on the German silver wires 33 34, the cooler one offering a better
path for the current than the other. This of course increases the strength of current
circulating in that one of the differential coils of the polarized relay which corresponds
to the cooler thermic wire, thus destroying the balance and shifting the armature of
the polarized relay, and operating a sounder 46 in a local circuit containing the
battery 45. Accordingly therefore the successive impulses of current arriving over
the cable has the effect of differentiating the resistance of the circuits which include the
thermic expansion wires and therefore differentiating the amount of current flowing in
the two normally balanced coils of the polarized relay, the armature of which latter
accordingly shiftss from one position to: the other and thus gives a - vigorous ** and

page_text: reliable movement for the operation of a local sounder, so that the signals may be
received according to the ordinary Morse system of telegraphy.
While I have shown and described transmitting and receiving apparatus both of
my own invention I desire to have it understood that either a transmitting apparatus
or receiving apparatus may be used independently in combination with receiving or
transmitting apparatus of other designs.
Having now particularly described and ascertained the nature of the inven
tion and in what manner the same is to be performed as communicated to me by
my foreign correspondent I declare that what I claim is :-
:-
1. The improvement in cable telegraphy consisting in charging the cable with impulses
of uniform duration and grounding the transmitting end of the cable upon the termina-
tion of the impulses whereby personal variations due to operators will be guarded
against.
2. The improvement in cable telegraphy consisting in charging the cable at each
signal with impulses of opposite polarity and grounding the transmitting end of the
cable upon the termination of each impulse, the times of charging being rendered
uniform mechanically to guard against personal variations due to operators.
3. The improvement in cable telegraphy consisting in reversing a charging current
on the cable with a make or break of the transmitting key, the duration of the
charging current being uniform and independent of the time during which the key
is held open or closed, and connecting the cable with ground to discharge the cable at
the transmitting end when the position of the key is shifted.
4. The combination of a local circuit controlled by a key, a pole-changer operated
by the local circuit, a switch operated upon a change of position of the key, said
switch normally grounding the cable but connecting it with a charging battery
through the pole-changer for a definite interval when the key changes position.
5. In cable telegraphy the combination of a cable, a pole-changer, a lever operating
between two stops, said lever being controlled by the transmitting key, a battery and
means for connecting the cable with the battery during transit of lever to either stop
and connecting it with the ground when the lever reaches either stop.
6. In cable telegraphy the described apparatus for transmitting comprising a local
circuit controlled by an operator's key, an armature lever actuated by the local
circuit, a pole-changer controlled by the armature lever for reversing a charging
battery upon the cable and a switch controlled by the armature lever, said switch
normally connecting the cable with ground but adapted to connect it with the battery
through the pole-changer during change of position of the armature lever.
7. In cable telegraphy the transmitting apparatus comprising a local circuit con-
taining a key and relay, an auxiliary local circuit controlled by the armature of the
relay, an electro-magnet in the auxiliary circuit charged at all times except when
the relay armature is in transit between its stops, a switch controlled by the armature
of the auxiliary magnet, said switch normally connecting the cable with ground but
connecting with a line charging battery while the relay armature is in transit between
its stops.
8. The momentum-actuated current-prolonging device for causing a greater con-
tinuance of current in a circuit after one notion of the key than after another
motion.
9. The receiving apparatus comprising a differential relay and a resistance varying
lay and
device for destroying the balance of the relay when current flows through the
cable.
10. The receiving apparatus comprising a coil of wire pivotally supported in a
magnetic field so as to move with reference to the field, when current flows through
the coil, and means for varying the resistance of two circuits including respectively
the coils of a differentially wound relay when the pivoted coil turns.
11. The combination of the iron-clad magnet with the suspended coil in its field of
force and a circuit closer, secured to the coil or its frame.
12. The combination with a differential receiving instrument of two thermic wires

page_text: in circuit with the respective differential coils and a magnetic device for varying the
temperature of the wires when a signal is transmitted. whereby the balance of the
receiving instrument is upset and the signal is reproduced.
13. The combination with a differential receiving instrument of two thermic wires
in circuit with the respective differential coils and a magnetic device for diverting
current from one thermic wire when a signal is transmitted, whereby the balance of
the receiving instrument is upset and the signal is reproduced.
14. The combination with a magnet having a coil of wire torsionally suspended
before its poles, connections between the coil and a telegraph line, a contact arm
operated by the coil and adapted to vary the relative strength of current flowing
through two circuits and thereby actuate differentially controlled receiving apparatus.
15. The combination of the iron-clad magnet, of a torsionally suspended frame
carrying a coil of wire in circuit with the cable, thermic wires respectively in different.
circuits, a contact device operated by the suspended coil and adapted to vary the
resistance of one circuit whereby one of the thermic wires heats more than the other,
and means for utilizing the difference in resistance of the thermic wires due to
difference in temperature to actuate a receiving instrument.
16. The combination of two thermic wires and a device controlled by current
passing over a telegraph line for causing unequal strengths of current to pass through
the thermic wires and heat them unequally thereby changing their relative resistance.
17. A telegraphic receiving instrument operated by the differential effect due to
the difference in heating of two wires, this difference being created when a current
passes over the telegraphic line.
Patou
COIS 1000 day or nugust lose.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.