Improvements in Telegraphy.
Year: 1893

page_text: Date of Application, 13th Nov., 1893-Accepted, 16th Dec., 1893
COMPLETE SPECIFICATION.
Improvements in Telegraphy.
I, PATRICK BERNARD DELANY, Electrical Engineer, a citizen of the United
States, residing at South Orange, in the County of Essex and State of New
Jersey, U.S.A. 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 comprises a system of telegraphy for operation over long or
difficult lines, such for instance as submarine cables, and, in fact it is specially
designed for working ocean cables. It involves features relating to the transmission
of the current impulses, the general character of the receiver devices, and special
constructions and modes of operation of such receivers to render them sensitive and
delicate in operation, and all co-operate to provide a system believed by me to
possess advantages and possibilities not heretofore attainable.
The primary object of my invention is to render the transmitted signals manifest
at the receiving station by local devices that are controlled or thrown into action
by the movement of the receiver proper in the main line. The receiver may be a
very delicate apparatus that will readily respond to weak depleted or attenuated
currents received over the line. The movable part of such a receiver is to control
a local circuit or circuits in which the more vigorously acting device or devices for
rendering the signals manifest are located. These devices may be, in general
character, of any well known type, that is to say, the received signals may be
indicated by sounds or recorded in any suitable manner.
In carrying out my invention I employ a swinging suspended or pivoted coil
included in the line, or a branch thereof, and located in a permanent magnetic field
of suitable strength. The apparatus resembles somewhat the corresponding parts
found in an ordinary Thomson cable recorder. In my system, however, the
swinging coil which carries or actuates a suitable contact maker that controls the
local circuit or circuits is entirely without bias and tends to remain at rest in any
position to which it may be brought by the action of the current, that is to say, its
inertia is the same for all positions and it has no tendency to return to any
particular position. In this respect it is different from those ordinary cable
receivers or recorders that are biased by springs, weights, bifilar filaments, magnetic
attraction or other means, so that they always tend to return to a normal or zero
position. A coil such as I purpose using may be pivoted or may be suspended, but
prefer to have it pivoted, because by the proper levelling and balancing of the
parts it may be absolutely unbiased, whereas a suspended coil, though practically
entirely unbiased for the purpose of this invention, might nevertheless have an
infinitely small tendency to return to a given or zero position.
I purpose using with such an unbiased receiving coil a system or means of trans-
mission in which the pulsations of current sent into the line at the sending end
shall be of alternating polarity or direction, and preferably as nearly as possible of
uniform duration. Further I prefer that the line shall be put to ground and so
remain during the intervals between the transmitted impulses, that is to say, when
the line is not connected with the source or sources of energy from which impulses
of current pass into the line, it shall be connected to earth, or the return conductor
in the event that a metallic circuit is being worked.
Further it is desirable that the relay or receiving apparatus whose local circuit
is made and broken by the contact carried or actuated by the swinging coil, shall
be wound with a high resistance to the end that the very light contacts effected by
the delicate contact maker may effect a proper and sufficient actuation of such

page_text: apparatus. prefer that the local apparatus of high resistance, whose circuit is
thus controlled, shall be a polarized relay so that the swinging contact maker at
one limit of its movement shall close the local circuit through the coil of the
polarized apparatus in one direction and when it is at the opposite limit of its
movement the local circuit shall be closed through the coil of the polarized
apparatus in the opposite direction. Or that the currents passed through the coil
of the polarized apparatus shall be alternately of opposite polarity, as is well under-
stood. I prefer that the polarized apparatus whose circuit is controlled through
the medium of the swinging coil shall be a relay, and that it shall in turn control a
local circuit containing a sounder or recorder. If it is desired that the received
message shall be read by sound and that a record shall also be preserved, the
apparatus in the circuit of the polarized relay may be a combined sounder and
recorder, or simply a recorder, as is well understood.
First, as to the general arrangement of relays, reference being had, at present to
Figure 1, this figure is a diagram showing a transmitter X and receiver Y connected
by a main line Ľ.
The
The organization of the receiving device is as follows: PM is a permanent
horse-shoe magnet. In its field and between its poles is a delicately piroted
swinging coil A through which the line passes to earth. V represents the ordinary
stationary core usually provided for such coils. The coil is entirely unbiased and
when properly balanced will tend to remain at rest in any position in which it may
be placed. It carries a light contact arm a of aluminium or other material that
plays between two contact stops a¹ a¹. Opposite poles of a local split battery 1 b
are respectively connected with these stops, and the contact arm a is connected with
the middle of said battery through the coil or coils of a polarized relay B.
armature of this relay is shown as controlling the local circuit of an ordinary
neutral sounder B. The contact between a and a¹, a' respectively may be protected
from sparking by a shunt containing a condenser or in other ways well known.
When an impulse of current of one polarity or direction traverses the coil it turns
to the right, and a comes in contact with one of the stops a¹, thus closing the
polarized relay circuit through one pole of its battery, and where a current of
opposite polarity or direction passes through the coil it swings to the left and a
makes contact with the other stop a'. The polarized relay or apparatus B may
act as a receiver but I prefer to have it serve as a relay for a recorder or sounder B¹.
The coil A is constructed and mounted so as to respond to very light currents, and
since it is entirely unbiased the only work performed by the current is the move-
ment in one direction or the other according to the polarity of the current.
the contacts between a and a', a¹ will be very light I use a suitable local battery b
and a polarized relay wound with a high resistance so that it readily responds to
relatively imperfect or light contacts at a, a, a', and I protect the contact against
sparks or welding action in any ordinary and suitable manner as above suggested.
In the drawings I have shown a condenser C in a shunt around the coils of the
relay B.
As
Second, as to the transmitting devices: It is desirable that the impulses of current
shall be of equal duration, and that the line should be put to earth (or the return
circuit) during the intervals between the impulses. To this end the transmitter
shown in Figure 1 may be employed. It is constructed and arranged as follows:
The line is connected to both stops of the armature of the polarized transmitter P T
and the armature is permanently connected to earth. These stops are connected
preferably through a resistance R with two insulated yielding contacts k k¹ one on
each side of the pivot of the transmitting key K. The main battery M B is
grounded in the middle at E and practically forms therefore two sources of current
and its two central or earth connected poles are therefore connected through the
earth with the transmitter armature. Its opposite poles are respectively connected
with the stops against which the contacts kk' on the key work as the key is
manipulated. The local battery L B that operates the polarized transmitter has
its middle connected with one terminal of the coils of that transmitter, the opposite

page_text: terminal of said coils is connected with the key K, and the opposite poles of the
local battery are respectively connected with the front and back stops m m' of the
key. The parts are so constructed and related that when the key is depressed
the insulated contact k¹ thereon, and the contact / connected with one pole of the
main battery are first closed before the key strikes its front stop m'. In like
manner when the key is raised contact is made between k and before the key
comes against its back stop m. The effect of this organization is as follows:
The apparatus being in condition for transmission and the key being up as indicated
in the drawing, the armature of the transmitter P T is against its stop t, the local
circuit being closed on the back stop m of the transmitting key. One pole of the
main battery is connected through the contacts lk and resistance R with the main
line, and is also grounded through the armature of the transmitter, the currents
from the battery being therefore shunted from the main line. When the key is
depressed the local circuit of the polarized transmitter is first opened; the con-
nection with the main battery is then broken at kl; the opposite pole of the battery
is connected with the line and earth through the contact and finally the other
pole of the local battery of the polarized transmitter is completed at the contact m¹
and the armature of the transmitter is thrown to its stop t¹. When the armature
of the transmitter is against either of its contacts the main battery is shunted from
the line, but during the flight of the armature from one contact to the other the
shunt is broken and the current from the battery M B passes to the line.
It will be perceived that the main line circuit is never open but is always
completed either through the armature of the polarized' transmitter, or through the
main battery M B. The resistance R may be adjusted to suit the conditions and
requirements of the circuit or may be dispensed with altogether. It is inserted
for the purpose of preventing an undue depletion of the battery when it is shunted
from the main line.
The length of time occupied by the armature of the transmitter in passing
from one stop to the other after the closing of the circuit of the local battery, and
consequently the duration of the impulses sent into the line, may be increased or
diminished by the proper manipulation and adjustment of the local battery L B
and the pole pieces of the polarized transmitter or of the limiting contacts tt', all
as is well understood, and to this end also a resistance R' may be placed in the
local circuit.
In order to render the movement of the armature of the transmitter sluggish and
thus increase the duration of the transmitted impulses, a tension may be put upon
the armature by means of a light spring O (Figure 2) so placed as to bear upon
the upper edge of the armature. The spring may be adjusted by means of a
screw
The static current from the line that may occur when the current is withdrawn
from the line by the establishment of the shunt through the armature of the
transmitter PT, will either discharge through said armature to earth or into the
other side of the circuit; or will be overcome by the current from the main battery.
The latter might be the case if the resistance R were so adjusted as to permit
sufficient current to enter the line when the armature is against one of its stops.
I prefer however to use the transmitter devices shown in Figure 3, and which are
as follows:
The line is connected with the armature lever of a polarized transmitter magnet
or relay PT and thence to the front stop of the armature lever of a neutral
magnet R, the lever being connected to earth. The magnet R normally (when the
key is raised) attracts its armature lever and the line is normally grounded. This
magnet is included in the circuit of a split battery S B, the middle of which is
connected through the coils of a polarized relay P, thence through the coils of
magnet R to the key lever K, and the poles of the battery are respectively
connected with the upper and lower stops m'm' of the key. The armature of R is
therefore released during the time the key is passing from one stop to the other.
Insulated yielding contacts on the key work against contacts connected

page_text: respectively with opposite poles of a main split battery M B, the middle of which
is grounded and the yielding contacts are respectively connected to the stops of the
armature lever of the polarized transmitter magnet P T. The polarized relay P,
is reversed by the manipulations of the key K, and its armature lever effects the
reversals of the magnet P T which is included in the circuit of the split battery L B.
If the key K be pressed down the circuit of the relay R which is included in the
circuit of local polarized relay P is broken and the earth connection removed from
the cable. Simultaneously with this disconnection the negative pole of main
battery M B is connected to the cable through yielding contact ¹ of key K and
armature of polarized transmitter P T. When the key K reaches its limiting
stop m¹ the circuit of relay R is again closed and the circuit of local polarized
relay P is reversed, which through local battery L B reverses polarized trans-
mitter PT thus disconnecting the cable from the main battery M B, regardless of
the length of time that the key K is held down. Simultaneously with this discon-
nection of the cable from the main battery the earth connection is re-established at
neutral relay R, which by the amount of movement of the armature and tension of
its spring is readily adjustable to the time of action of polarized magnets P and PT,
so that the earth connection is substituted for the battery at the exact instant of
the disconnection of the latter. Upon releasing the key the polarized relays P
and P T are reversed, relay R is actuated in the same way as when the key was
depressed and a reverse current is sent into the cable from main battery M B and
is followed by an earth connection in the manner described. It will be apparent
that this organization admits of impulses of equal duration and reverse polarity
being sent from the transmitting station so as to represent on a polarized or cable
receiver dots or dashes according to the length of time that the key K may be held
down. And that during the time intervening between successive impulses the cable
is connected direct to earth for the purpose of discharging any current that may
ensue upon the termination of the signal impulse. Should impulses of longer
duration be desired it will be only necessary to introduce an additional local
polarized relay P and an additional local neutral relay R.
It will be a simple matter to adjust the time movement of the neutral relay
armature to any extent required for absolute coincidence with the movement of the
armature lever of the polarized relay P so that there shall be neither break or
injurious lapping between the connections to earth and main battery. A simple
galvanometer temporarily switched into the circuit of the wire extending from the
lever of polarized relay P T to front contact of R say at X'would indicate
unerringly when the movements of the two levers were in proper relation.
Third, the form of receiver devices which I prefer to employ is shown in
Figure 4. It involves a new organization and mode of operation. The movable
coil of the receiver is of the character herein before described.
When an impulse of current of one polarity passes in the coil it swings in one
direction, and the passage of a current of opposite polarity or direction causes it to
swing in the other direction. Its movement in either direction is limited by stops,
preferably non-metallic. The end of the contact arm extending beyond these stops
plays between two contacts carried by the rocking armature lever of a polarized
relay or electro-magnet. The relation of the two pairs of stops to the contact arm
is such that when moving in either direction the outer end of the arm first strikes
the electrical contact or stop, whereupon a local circuit is completed. The com-
pletion of this local circuit effects the movement of the armature lever of the
polarized electro-magnet in the same direction as that in which the contact arm
carried by the unbiased swinging coil is moving. The contact arm and rocking
armature lever move together until the contact arm comes against its limiting stop,
then the continued movement of the armature lever carries the contact stop thereon
away from the contact arm and the local circuit is broken. On the completion of
the movement of the armature lever of the polarized magnet in one direction the
local circuit of a sounder, recorder or register is closed, thus rendering manifest
the signal represented by the received impulse that has caused the movement

page_text: of the swinging coil. The contact arm or the con now Dears against
stop, preferably made of insulating material, and is separated from the
electrical stop carried by the armature lever, so that any trembling, chattering or
vibration of the arm from any cause whatever does not affect the sounder or other
receiving apparatus. In other words the first movement of the contact arm results
in the production of the intended signal in a complete and perfect manner, and any
subsequent vibration or chattering of the arm against its limiting stop cannot
mutilate the signal. The magnet included in the local circuit closed by the
contact arm is preferably wound with a relatively high resistance, so that it will
readily respond to the delicate contacts completed by the slight pressure of the arm
upon its contacts.
I also provide on the rocking armature lever two relatively minute pieces of iron,
arranged one on each side of the contact arm and preferably mounted on the ends
of non-magnetic adjusting screws carried by the rocking armature lever of the
polarized magnet before mentioned but they may be otherwise arranged. These
pieces of iron become polarized from the magnetic field of the magnet of the main
receiving coil, and act upon a small armature mounted upon the swinging contact
arm. They are so adjusted that when the contact arm has been moved against one
of the contact stops on the rocking armature lever of the polarized magnet to
complete the local circuit before described, the small armature on the contact arm
comes into the field of the small piece of polarized iron located on the same side of
the arm as said contact stop and is attracted. The contact between the arm and
its contact stop is thus reinforced, and, as the rocking armature now moves with
When the
the arm the magnetic attraction assists the movement of the arm.
contact arm is arrested by its non-metallic stop, both the contact stop and polarized
piece of iron are, by the further movement of the armature lever carried away from
the contact arm, which then lies against its non-metallic limiting stop and out of
contact with said contact stop, so that any trembling or chattering of the arm will not
mutilate the signal. The forcible separation of the arm and the contact overcomes
any welding or sticking of the contacts, which would otherwise have to be over-
come by the next movement of the arm under the influence of a reverse current in
the main line coil. This is an important feature in apparatus of this class and is
believed to be novel. The limiting stops are made of non-metallic material to
avoid any tendency to sticking, either from magnetic or current effects therein.
When the contact arm has been arrested and the rocking armature lever continues
its flight as just described, the contact stop and polarized iron piece on the opposite
side of the contact arm are carried toward the arm and into proper position to effect
a repetition of the operation just described when the contact arin moves in the
opposite direction.
A description of my improved method of operation will be deferred until after
the apparatus is described in detail with reference to Figure 4.
A is a permanent magnet, between the poles of which is located the unbiased
swinging coil (shown pivoted) through which the main line L is connected. The
coil carries a contact arm C that plays between two limiting stops e c, preferably of
insulating material. The end of the arm extending beyond these stops plays
between two insulated metallic stops c¹ c', carried by the armature lever D of a
polarized magnet E. F is a polarized relay, one terminal of the coils of which
is connected with the arm C. The other terminal is connected with the middle
of a split battery 1b whose poles are respectively connected with the stop c¹ c'.
The armature lever of the relay F controls the local circuit of the polarized
magnet E, and the armature lever D of this latter magnet controls the local
circuit of an ordinary sounder, register or recorder 'S. If it is desired that the
message shall be received by sound and also be recorded, S may be a combined
recorder and sounder, as is well understood. G, G, are the two small pieces of iron
carried by non-magnetic adjustable screws G¹, G' mounted on the armature lever D,
and G is their small armature carried by the contact arm.
In cable telegraphy an electrical condition of the cable sometimes exists that

page_text: .
tends to maintain the receiving coil in a displaced or biased position to one side of
the theoretical central position. Such influences are generally ascribed to "earth
currents" and may be prolonged for several minutes at a time, or longer. The
effect of such currents is to give the coil of the receiver a tendency to remain in
one position more than another. Should this condition of affairs arise in my system
it would be desirable to accommodate the apparatus to the varying conditions_and
this may be accomplished in the following manner. The polarized magnet E its
armature lever and the non-magnetic limiting stops of the contact arm are all
carried by a frame or bed piece O that may be adjusted in an arc of which the axis
of the main line receiving coil is the centre. For instance the frame O may have
curved arms o that embrace and turn upon a hub O' arranged on the base of the
instrument concentric with the axis upon which the receiving coil turns. The
opposite end of the frame may have a dovetail lug on its under face that travels in
a curved way or track 0, and the frame may be adjusted by a screw P mounted in
a post P and engaging a lug on the frame. The proper parallelism of the parts
in radial lines of which the axis of the coil is the centre may be maintained. As
the operator notices any disturbances of the character stated he may suitably
adjust the parts without interrupting the operation of the instrument by manipulation
of the adjusting screw P.
The small pieces of iron, being inductively polarized by the field of the receiver
magnet, act attractively upon the minute armature carried by the contact arm, and
they may be so adjusted with reference to this armature that when the contact
arm is moved in one direction, thus closing the local circuit, and effecting the
rocking of the armature lever in the same direction, the small magnetic piece that
is thereby caused to approach the contact arm may be brought, when the rocking
lever has reached the limit of its movement, in such proximity to the armature on
the contact arm that it will exert attractive force upon the armature just sufficient
to draw the contact arm towards it and close the local circuit on its other contact,
thus effecting a movement of the rocking armature lever in the reverse direction
and effecting a repetition of the operation just described. With no current passing
in the main line these parts of the receiver may therefore be so adjusted as to just
maintain a regular automatic oscillation of the contact arm and of the coil which
carries or actuates it. When this condition of oscillation is established the passage
of a very light current in the main receiver coil will hold the contact arm in one
position or the other, according to the polarity or direction of said current, and
effect the manifestation of the desired signal in the manner already described. For
instance if a positive current is passing in the coil, the coil will be maintained in
one position, say with the contact arm to the right; when a negative current or
one of opposite direction to the first mentioned current passes, the coil will be
moved to the left and so maintained as long as the current is sufficiently effective
in the coil. If, therefore, this condition of equilibrium has been established and
received currents alternating in polarity or direction pass in the main line coil the
desired signal will be produced upon the receiver by the arresting effect of the
main line current. When working with this adjustment of the instrument the parts
could be so related that the attractive force of the small pieces of iron upon their
armature would become effective to move the contact arm at the expiration of a
period sufficient to produce the longest signal or dash, that is to say the attractive
force of the polarized iron pieces will move the contact arm and terminate the
signal at a time when the tailing current in the coil has become sufficiently weak
or depleted.
Or I may adjust the apparatus otherwise, i.e., so that the attractive effect of the
small pieces of iron upon their armature on the contact arm will be almost, but not
quite sufficient to cause the oscillation of the arm in the manner above described.
In that event, the received impulses passing in the main line coil would have but a
minimum of work to perform and the coil would respond to the lightest current.
The mode of operation first described contemplates that the local devices shall
exert an effect upon the contact arm just sufficient to regularly move it, and the

page_text: received main line signal currents have merely to restrain or overcome this ten-
dency to continued oscillation, and the adjustment may be such that extremely
attenuated main line currents will effectively render themselves manifest upon the
receiving devices. In the mode of operation last described the local devices exert
an effect upon the contact arm not quite sufficient to move it and the received main
line currents have only to supply the relatively small additional amount of energy
to effect the proper movement of the arm.
Both modes of operation are included, therefore, in one novel method which
consists in locally influencing the movable part of the receiver to reduce the amount
of energy reruired to control it to effect the production of the desired signals, and
then supplying the energy required to exert such control from signal currents
received over the main line.
It will be seen, therefore, that these devices effect a reduction of the influence
that has moved or tended to move the contact arm in the direction in which it has
last moved, because the attractive piece acting thereon is moved away from the
arm, while the influence that will move or tend to move the arm in the opposite
direction is increased because the other attractive piece is moved toward the other
side of the arm.
The rocking-arm of the local polarized instrument carrying the local contacts
affords in effect a movable zero for the contact arm of the main receiving coil, for
when the rocking arm reaches its limit after moving in the same direction as the
contact arm of the main coil, the contact point on the opposite side has been carried
along at the same time and left close to the contact arm, so that the slightest
movement in the return direction under the influence of the main current brings it
into contact with the other local contact post which results in a return or reverse
movement of the rocking-lever. It will be seen that while the movement of the
main coil arm may be very slight, the movement of the rocking-arm and the con-
tacts and attracting pieces carried thereby may be comparatively great, so as to
insure a clear break between the contact arm of the main coil and the local contact
points of the polarized relay and also to increase the discrepancy by reason of
distance, between the attracting power of one attracting point over the other,
always leaving the one on the side to which the main arm is to next move, closer to
the small piece of iron or armature on the arm than the one which has last assisted
in moving the contact arm.
So far as I am aware all other receivers for circuits or cables for which this
receiver is especially designed have relied upon the weak and depleted currents
arriving to actuate the movable part of the receiver and the rate at which this
movable part may be actuated depends upon their delicacy of adjustment.
Assuming that the movable part of my receiver may be as sensitively adjusted as
the instrument now in use my system possesses the great advantages of overcoming
by purely local means practically all the inertia of the movable part of the receiver
and effects of the tailing of the inain line current so that the power of the feeble
current coming over the cable instead of being expended in overcoming this inertia
and current tailings is simply added to local power which may have already over-
come 99 per cent. thereof and emphasizes or reinforces the movement of the movable
part of the receiver converting an exceedingly feeble aud uncertain movement into a
positive and quick movement, thereby not only rendering signals certain and
definite, but by reason of this increased power and quickness of movement greatly
increasing the speed at which cables may be operated.
The receiving instrument at one point may be made the transmitter for another
circuit making it possible to operate any distance desired, or to join up long or
short cables into a practically continuous circuit. At present the transfer of
messages from one long cable to another or to a short cable must necessarily be
effected by manual retransmission which causes delay and errors.
Another form of receiver embodying in great part the principles of construction
and operation of that shown in Figure 4 is illustrated in Figure 3.

page_text: The general construction is the same as in Figure 4 as will be apparent, since
corresponding reference letters indicate like parts, except however as hereinafter
appears.
GG are two small solenoids, that may have iron cores to increase the effect,
carried by the armature lever D, and respectively included in the local circuit
between the poles of the battery 16 and the contacts c¹. These magnets or
solenoids when energized attract a minute armature G¹ carried by the contact
arm C.
Ignoring for the present the magnets G and their armature.G¹ the operation is
as follows: Assuming that a positive impulse passes in the coil B, the contact
arm C would be moved say to the right. It first comes in contact with the right
hand metallic contact c¹ carried by the armature lever D. On a difficult circuit
this movement of the arm C may be very delicate and have but little power, but
nevertheless the contact with e¹ will be sufficient to charge the magnet which is
also delicately adjusted and effect the movement of its armature from one stop to
the other. Thereupon the local circuit of E is firmly closed, and the armature
lever D also moves to the right. The contact arm C will naturally follow this
movement because of the tailing or duration of the current impulse in the coil B,
but when the arm strikes its limiting stop c, the metallic contact c¹ leaves the
arrested arm, and on the completion of the movement of the armature lever D,
the signal will be produced upon the instrument S, and the arm C left entirely
free to be moved in the opposite direction. With the parts in the condition which
they have now assumed the trembling of the arm C upon its limiting stop c cannot
in any way mutilate or effect the perfect manifestation of the signal by the
instrument S. The next transmitted impulse being one of opposite polarity, the
coil B will swing in the opposite direction and carry its arm C against the left
hand metallic contact c', which marks the termination of the signal, the operation
being obvious and as already described. The feeble trembling and comparatively
uncertain movements of the arm C are thus translated into distinct and vigorous
actions that effect locally the manifestation of the signal.
Where the magnets G are employed, their initial effect is of course to reinforce
the contact between C and c', for no matter how slight or imperfect the contact
between arm C and contact c¹ may be at first, it is instantly improved by the
attraction of G, and then on the movement of the armature lever D, the magnet G
that is then energized draws the contact armı C along with it until the arm is
arrested by its limiting stop c.
As usual the coil B may have a stationary iron core X. The arm C may be
counterbalanced by a rearwardly projecting weight Y shown in dotted lines as
located below the upper arm of the bracket in which the coil is pivoted.
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 combination with a main line and transmitting devices at one end
thereof for sending currents of alternating polarity into the line, of a receiving
apparatus at the other end of the line having an unbiased movable part that
responds to said currents, a local circuit controlled thereby, and an instrument in
said local circuit adapted to be worked by reverse currents traversing the same.
2. The combination, with a line and transmitting devices at one end thereof for
sending currents of equal duration and alternating polarity into the line and
grounding the line between said currents, of receiving apparatus having an
unbiased movable part that responds to the alternating currents received over the
line and a local circuit controlled thereby.
3. The combination with a line and transmitting devices at one end thereof for
sending currents of equal duration and alternating polarity into the line and
grounding the line between said currents, of a receiving apparatus consisting of a

page_text: magnet, an unbiased swinging coil located in the field of the magnet and included
n the line, a contact maker carried or actuated by said coil its contact stops, the
ocal circuit controlled thereby and the polarized instrument in said circuit.
4. A cable receiving apparatus consisting of the combination of the magnet, the
swinging unbiased main line coil located in the field thereof, the contact maker
carried or actuated by the coil, its contact stops, the local circuit, and a polarized
instrument of relatively high resistance included in the local circuit, substantially
as set forth.
5. A cable receiving apparatus consisting of the combination of the receiver-
magnet, the swinging main line coil located in the field thereof, the contact maker
carried or actuated by the coil, its contact stops, a local circuit controlled by the
movement of said coil, a polarized relay of relatively high resistance included in
said local circuit, a second local circuit controlled by said polarized relay, and a
repeater, sounder, recorder or final receiver included in said local circuit.
6. The combination with a line, and transmitting devices at one end thereof for
sending currents of opposite polarity and practically equal duration into the line
and grounding the line between said currents, of a receiver consisting of a magnet,
a movable coil in the field of said magnet and surrounding an iron core, said coil
being included in the line, a contact inaker carried or actuated by said coil, its
limiting contact stops, the local circuit controlled thereby, and a polarized
instrument in said circuit.
7. The combination of the line, the polarized instruments P T and P, the
magnet R, key K and batteries and circuit connections, substantially as set
forth.
8. The combination with the line, main battery and key, of means whereby at
each depression or elevation of the key the normal ground connection of the line is
removed the line connected to the battery for a definite predetermined period and
then disconnected therefrom and connected to its normal ground irrespective of the
length of time the key may be held depressed or elevated by the operator.
9. The combination of a receiver having a movable part adapted to be moved in
opposite directions by received currents of unlike polarity or direction, local
devices magnetically influencing said part and tending to move it in opposite
directions, and means controlled by the receiver for reducing the influence tending
to move the movable part in the direction in which it has last moved and increasing
the influence tending to move it in the opposite or return direction, whereby
greater sensitiveness of the main receiver is obtained, substantially as
forth.
set
10. In telegraphic receiver, the combination of the movable part thereof,
local means influencing said part and acting oppositely thereupon to alternately
move it in opposite directions and local means controlled by the movable part of
the receiver to successively decrease the influence acting to move said part in the
direction in which it has last moved and simultaneously increasing the influence
acting to move it in the opposite or return direction.
11. The combination of the movable part of a receiver, local devices magnetically
influencing said part and tending to move it in opposite directions, and means
controlled by the receiver for reducing the influence tending to move said part in
the direction in which it has last moved and increasing the influence tending to
move it in the opposite or return direction, substantially as set forth.
12. The combination of a receiver, having a movable part adapted to be moved
in opposite directions by received currents of unlike polarity or direction, local
devices influencing said part and tending to move it in opposite directions, and
means controlled by the receiver for reducing the influence tending to move the
movable part in the direction in which it has last moved and increasing the
influence tending to move it in the opposite or return direction whereby greater
sensitiveness of the receiver is obtained, substantially as set forth.
13. The combination of the movable part of a receiver, local devices influencing
.said part and tending to move it in opposite directions and local means controlled
B

page_text: by the movable part of the receiver for reducing the influence tending to move
said part in the direction in which it has last moved and increasing the
influence tending to move it in the opposite or return direction, substantially as
set forth.
14. In a telegraphic receiver the combination of a movable contact maker, two
stops on each side thereof, one a movable contact stop, and the other a final
limiting stop two pieces of polarized iron mounted one on each side of the contact
maker and moving with the movable contact stops and an armature carried by the
contact maker, substantially as set forth.
15. In a telegraphic receiver, the combination of a magnet, the swinging main-
line coil located in the field thereof, a contact maker carried or moved by said coil,
a movable contact stop and a movable piece of soft iron mounted on each side of the
contact maker and an armature, the movable pieces of iron being magnetized by the
receiver magnet, substantially as set forth.
16. In a telegraphic receiver, the combination of the main receiver magnet, an
unbiased movable main line coil located in the field thereof, the contact maker
carried or actuated thereby, a polarized magnet, its rocking armature lever, a
contact stop and an iron piece arranged on each side of the contact maker and
carried by the rocking armature lever, an armature for said iron pieces carried by
the contact maker, the limiting stops of the contact maker and a local circuit
controlled at the contact stops that effects the movement of the armature lever, the
combination being and operating substantially as set forth.
17. In a telegraphic receiver, the combination of the movable part of the receiver
actuated by the main line currents, two attractive devices one on each side thereof
and acting thereupon to tend to cause its movement in opposite directions, and
means controlled by the movable part of the receiver for effecting the joint move-
ment of said attractive devices, whereby when one of them is moved away from one
side of the said movable part of the receiver the other one is moved into proximity
to the other side thereof, substantially as set forth.
18. In a telegraphic receiver the combination of two magnetic devices creating
two magnetic fields, the movable part of a receiver located in and attractively
acted upon by both fields and devices controlled by the movable part of the receiver
for causing the approach of one field toward the movable part as the other is moved
away from it.
19. The combination of a device creating a permanent stationary magnetic field,
the movable part of a receiver located in said field, two magnetic pieces located in
said field and arranged to attract the movable part in opposite directions, and
devices control by the movable nart of the receiver for effecting the movement
of said pieces and causing one of them to approach the movable part of the receiver
as the other recedes from it.
11 a
20. The combination of the movable part of a receiver of electrical impulses, a
local magnetic device acting thereupon and tending to cause its movement, means
whereby the received main line current is caused to supplement the action of said
local device and effect the movement of said part of the receiver in the direction
in which it tends to move, and means controlled by said movable part for moving
the magnetic device away from said part of the receiver.
21. In a telegraphic receiver the combination of a movable contact maker, two
stops on each side thereof, one a movable contact stop, and the other a fixed
limiting stop, two pieces of polarized iron mounted one on each side of the contact
maker and moving with the movable contact stops, an armature carried by the
contact maker, and means for bodily adjusting the iron pieces and movable stops in
an arc of which the centre of motion of the movable part of the receiver is the
centre, substantially as set forth.
22. In a telegraphic receiver, the combination of a magnet, the swinging main-
line coil located in the field thereof, a contact maker carried or moved by said coil,
a movable contact stop and a movable piece of soft iron mounted on each side of
the contact maker, an armature, the movable pieces of iron being inductively

page_text: polarized from the receiver magnet, and means for bodily adjusting the iron pieces
and movable stops to maintain their parallelism with the contact maker in radial
lines of which the axis of the coil is the centre, substantially as set forth.
23. In a telegraphic receiver, the combination with the swinging coil actuated by
received impulses of current, and the contact arm carried or actuated thereby, of
the limiting stops or contacts between which said arm works, the normally
stationary support on which they are mounted, and means for gradually adjusting
such support in an arc whose centre of motion is the centre of motion of the coil to
change at will the position of said stops or contacts to adapt them to the biased
position of the contact arm due to earth currents or other extraneous causes.
24. In a telegraphic receiver, the combination of the movable contact maker
of the receiver and two contacts or stops on each side thereof, one a temporary
movable contact, and the other a fixed limiting stop with means for moving the
temporary contacts away from said contact maker, substantially as and for the
purpose set forth.
25. In a telegraphic receiver, the combination of the unbiased movable part of
the receiver, its contact maker, and two contacts or stops on each side thereof,
one a movable contact, and the other a fixed limiting stop, substantially as and
for the purpose set forth.
26. The combination of the swinging coil, the magnet in whose field it is located,
an arm carried or actuated by the coil, its fixed limiting stops, its contact stops
carried by an armature lever and a local circuit controlled at said contact stops
and by means of which the movement of said armature lever is effected, substan-
tially as and for the purpose set forth.
27. In a telegraphic receiver, the combination of a magnet, a swinging unbiased
coil located in the field thereof, an arın carried or actuated by the coil, two stops
on each side of the arm, one a limiting stop and one a movable contact stop,
a local circuit controlled by said contact stops, a polarized relay in said local
circuit, a second local circuit controlled by said relay, a second polarized relay in
said second local circuit and its armature lever carrying said movable contact stops,
and a third local circuit containing a sounder or recording receiver controlled by
said armature lever.
28. In a telegraphic receiver the combination of the movable part of the
receiver, a limiting stop against which it works, a temporary movable contact with
which it also comes in contact, and local means controlled by the movable part of
the receiver for effecting the separation of said movable part of the receiver and
said movable contact while the former is held or arrested by the fixed stop, sub-
stantially as set forth.
29. The combination of the movable contact maker of the receiver, a contact
stop against which the contact maker first comes in its movement, a local circuit
completed at said contact, a movable part actuated through the completion of the
local circuit to move in the same direction with the contact inaker and with which
the contact stop moves, and an arresting or limiting stop, whereby when the
contact maker comes against its arresting stop the contact stop is forcibly carried
out of contact with and away from the contact maker.
30. In a telegraphic receiver, the combination from the movable contact maker
of the receiver and a movable contact stop on each side of the movable contact
maker, against which the movable contact maker comes in contact, of means for
moving the contact stop away from the contact maker, substantially as and for the
purpose set forth.
31. In a telegraphic receiver the combination of the unbiased movable part of the
receiver to be actuated in either direction by main line currents, a local circuit
controlled thereby and means whereby said circuit is closed and then broken
during a single movement of said part in either direction, substantially as set
forth.
32. In a telegraphic receiver the combination of the movable part of the receiver

page_text: to be actuated in either direction by a main line current, a local circuit controlled
thereby, means whereby said circuit is closed and then broken during a single
movement of said part in either direction, and a magnet or receiving instrument
through which the local circuit is completed at each movement of the receiver in
either direction, substantially as set forth.
33. In a telegraphic receiver, the combination of the part of the receiver actuated
in opposite directions by main line currents, a local circuit controlled thereby,
means whereby said local circuit is closed and then broken during the movement of
said part in either direction, and a polarized relay in the local circuit, substantially
as set forth.
34. The combination of the movable part of the receiver actuated in either
direction by main line impulses, a local circuit controlled thereby, contacts by which
the local circuit is completed upon the movement of said part in either direction,
and local devices controlled by the movable part of the receiver for opening the
local circuit, after it has been thus closed, independently of the cessation of the main
line impulse, substantially as set forth.
35. The combination of the movable part of the receiver actuated in either
direction by currents of opposite direction or polarity, a local circuit controlled
thereby, contacts by which the local circuit is completed upon the movement of said
part in either direction, and local devices controlled by the movable part of the
receiver for opening the local circuit after it has been thus closed, substantially as
set forth.
36. In a telegraphic receiver, the combination of the movable part of the receiver
actuated by main line current, the contact part against which it bears when moved
by the main line current to complete a local circuit, and local means controlled by
the movable part of the receiver and co-acting there with upon each actuation
thereof for increasing the contact pressure between said parts, substantially as set
forth.
37. In a telegraphic receiver the combination of the movable part of the receiver
actuated by main line currents, the contact against which it bears, when moved by
the main line current, to complete a local circuit, means controlled by the movable
part of the receiver and co-acting therewith on each actuation for increasing the
contact pressure between said parts, and local means controlled by the movable part
of the receiver for opening the local circuit after it has thus been closed,
substantially as set forth.
38. In a. telegraphic receiver, the combination of the movable part of the receiver
adapted to be actuated in either direction by currents of opposite direction or
polarity, a contact against which it bears when moved in either direction, a local
circuit completed at said contact, means controlled by the movable part of the
receiver for increasing the contact pressure between said parts, and local means
controlled by the movable part of the receiver for opening the local circuit after it
has thus been completed.
39. In a telegraphic receiver the combination of the movable part of the receiver,
the contact against which it bears, when moved to complete a local circuit, means
controlled by the movable part of the receiver and co-acting therewith on each
actuation for increasing the contact pressure between said parts, and means for
throwing the contact pressure increasing means out of action before the com-
mencement of the return or backward movable part of the receiver, substantially as
set forth.
40. The combination of the movable part of the receiver actuated in either
direction by main line impulses, a local circuit controlled thereby, contacts by which
the local circuit is completed upon the movement of said part in either direction,
local means controlled by the movable part of the receiver for increasing the contact
pressure between said part and the local circuit contacts, and local means controlled
by said movable part for opening the local circuit independently of the cessation of
the main line currents.

page_text: 41. The organization of apparatus for transmission, substantially as shown in
Figure 3.
42. The method of an apparatus for reception of signals, substantially as described
in Figure 4.
Dated this 9th day of October 1893.
PATRICK BERNARD DELANY.