Improvements in Electrical Telegraph Systems and Apparatus therefor.
Year: 1897

page_text: Date of Application, 25th May, 1897-Accepted, 21st Aug., 1897
[Communicated from abroad by CHARLES GOODWIN BURKE, of 48 Broad Street, New
York, United States of America, Electrician.]
Improvements in Electrical Telegraph Systems and 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 :-
The invention which forms the subject of the present application for letters
patent relates to Systems of Telegraphy in which electric impulses are transmitted
from one end of a line and received and recorded at the other in characters
distinguished as dots and dashes, or, in general, those in which the signals are
transmitted and recorded in accordance with what is technically known as the
Morse code.
It is well known that in long lines, wholly or in part submerged, underground, or,
in general, of large static capacity, the effects of induction peculiar to all such lines
not only render rapid working a matter of great difficulty, but have heretofore
proved an insuperable obstacle to the practical transmission and receipt of distant
signals of sufficient variation in length to be recognizable as those corresponding
to the characters of the Morse code. This is due to the fact that the discharge of a
cable or a circuit of large static capacity is relatively less rapid and complete after
an impulse required to produce a dash, than after such momentary impulses as are
sufficient to produce Morse dots, so that in the case of mixed signals composed of
a succession of dots and dashes, this relative inequality in the time and degree of
discharge of the line causes such distortion and irregularity in the signals as
received or recorded as, generally, to render them entirely unintelligible. This
liability to confusion of signals on long cables and similar lines has been partially
corrected by the adoption of various expedients, but up to the present time
nothing has been devised or proposed which wholly overcomes the difficulty, and
the universal practice is now to send short impulses of one polarity to produce
effects in the mirror instrument or characters on the Syphon Recorder corre-
sponding to Morse dots, and similar impulses of the opposite polarity for
dashes.
There exists, however, the serious objection to this plan, that the signals can
only be distinguished by a skillful determination of their direction and extent
of deflection from a given point or line, and the records are necessarily more or less
illegible, uneven and uncertain, and, therefore, unreliable.
Moreover, as will be understood, it is very difficult to relay or retransmit
signals automatically, the elements of which are of opposite polarities, particularly
where the line conditions demand the use of very sensitive instruments, such as
are now employed on cables.
The present invention has for its object to render feasible and practicable the

page_text: application of the Morse code to the operation of submarine and similar circuits
without regard to their length and inductive capacity, and so that all work
may be automatically relayed and repeated with entire facility. The invention
involves a new method of transmitting and receiving the signals, and also certain
novel instrumentalities for effecting these operations.
Heretofore Morse signals over all kinds of circuits have been reproduced and
recorded at the receiving stations by the effect of electrical impulses, transmitted
over the line, upon instruments connected directly or indirectly therewith, or
through local instruments controlled by them, but always in such manner, or under
such conditions, that the distinguishing characteristics of the dots and dashes
resulted from a corresponding duration or length of the battery contact with
the line.
According to the present invention the recorded signals at the receiving station
are not caused by the electrical impulses which are transmitted over the line, but by
mechanical means which operate only in the intervals between the passage of
impulses over the line, or after such impulses have ceased. These impulses, more-
over, are of uniform duration and occupy no longer time than is sufficient for the
accomplishment of their purpose.
At the sending end of the line means are employed by which electrical impulses
of uniform duration may be transmitted, and by these impulses the beginning and
ending of time periods of predetermined lengths at the receiving station are
defined. At the receiving end of the line there employed a recording instrument
organized to respond to these impulses and to denote and record by mechanical
means the time intervals occuring between them. As these intervals may be made
shorter to correspond with dots and longer to correspond with dashes, it follows
that any desired succession of characters readable as dots and dashes may in this
way be transmitted and recorded by current impulscs of uniform duration.
Referring now to the drawings for a more specific description of the method and
apparatus comprised in the invention.
Fig. 1 is a diagram illustrating the system in its simplest form.
Fig. 2 is a modification of the same illustrating the use of an automatic
transmitter.
Fig. 3 is a diagram illustrating a plan for clearing the line after each impulse.
Figs. 4, 5 and 6 are views of perforated tapes to be used in transmitting, and
the printed record made thereby.
Fig. 7 is a plan view of a portion of the apparatus used in transmitting and
illustrating an improved perforated transmitting tape.
Fig. 8 is a view partly in elevation and partly in section of the perforating
mechanism which is preferably used for preparing the tapes.
Fig. 9 is a longitudinal section of Fig. 8, and
Fig. 10 is a diagram illustrating a modified form of perforating apparatus.
Referring to Fig. 1 for an illustration of the principle of the invention, A.
represents a telegraph line with transmitting and receiving instruments connected
therewith at each end.
B and B are the line batteries; C, C₁ the transmitters, which in this instance
are shown in their simplest form as ordinary keys, and D, D¹ the receiving
instruments.
The keys have front and back contacts a, a¹ and stops c, c¹, insulated from each
other, and by means of spiral springs or otherwise are normally held down on the
front stops c.
One pole of the line battery B is grounded. The other pole is connected with the
back stops c¹. The line is branched at each station, one branch leading to the back
contact a¹ and the other to the front stop c¹ of the key.
Between the earth and the front contact of the key is a relay magnet d, which
controls a local circuit e, containing a battery f and the electro-magnet g of a
recording instrument. The local circuits may also contain a repeating or relay
magnet h when so desired.

page_text: The operation of the system as thus organized is as follows:-The operator at
the sending end of the line first lifts the key C so that it rests upon its back-stops.
This sends a current to line, and the recording instrument, which, in the absence
of line current makes a continuous mark, ceases to trace such line and is in
condition for recording signals. With the key raised, the further manipulation is
precisely the same as for sending ordinary Morse. For example, if the letter I is
to be sent, the operator simply makes two dots or short depressions of the key
immediately after raising it, and this shuts off the current from the line for two short
periods between the three contacts which such movements of the key involve. If
the next letter to be sent is, say, N, which is represented by a dash and a dot,
the operator, after permitting the key to remain down and the current thereby
cut off long enough for a letter space, raises and depresses it for a dash, during
which operation he connects and interrupts the line current, thereby producing a
dash, and then proceeds for a dot as before explained.
The record made by the recording instrument will be in ordinary Morse
characters, which will correspond, not to the presence and duration of electric
impulses over the line, but to the absence of such impulses and the intervals
between them.
Ordinarily the transmission of signals would not be effected by a hand key, as
the manipulation of such an instrument would be difficult, but by a perforated
tape or some other automatic means For example, a tape like that shown at T
in Fig. 4 is prepared by punching out of a paper strip a line of holes, the
position and number of which determine and correspond to the number of
impulses to be sent and the intervals between them.
If this tape be drawn through a transmitting instrument C" provided with a
pivoted contact lever all with a trailer point 611, the movements of the lever, due
to the trailer dropping through the perforations, will make and break the
circuit, and send impulses to line and to receiver D¹ corresponding to the
perforations.
On the diagram illustrating the tape T are shown a series of letters, and
beneath them the perforations are indicated which would be necessary to pro-
dacing such letters. At T¹ is shown a tape with the record thereon which
would be produced by the recorder of Fig. 1, and on which the regular Morse
characters of the Continental Code are seen between the longer lines which
indicate spaces.
At T2 in Fig. 4 is shown a tape with marks thereon which
correspond in number and position with the number and time of the actual
impulses transmitted over the line.
It will be understood that, in this improved system, the current being off the
line during pauses in transmission, such, for instance, as are necessary between
individual letters and complete words, the recording instrument at the receiving
end will produce a continuous ink line or mark upon the tape. To avoid this it
would be necessary to employ a special form of self starting and stopping-recorder,
or to send independent impulses over the line between letters and words, which
might be either shorter than dots or longer than dashes. Ordinarily, however,
the perforated strip for transmission is so prepared that a difference in the spaces
between perforations equal to the distance which it is intended to separate letters
and words in the record is provided so that these distances will be indicated by
marks on the receiving paper longer than those which represent dashes. By this
plan all letters are isolated or separated from one another by marks. distinctly
longer than that for a dash, whilst words are separated by marks distinguishably
longer than those between letters.
This method of spacing between letters and words is particularly valuable in all
code messages in which the words often consist of arbitrary combinations of letters
or figures arranged singly or in groups, or of unfamiliar and foreign words, as
well as effectually preventing the vexatious errors which arise from imperfect
spacing so common under present methods, and whereby the elements of approxi-
mate letters are made to assume misleading combinations.

page_text: A further feature of the invention is, however, a special and novel plan for
spacing between letters which produces a record more in conformity with that of
the present Morse system, and this consists in slightly elongating the perforation
which concludes each letter. This addition to the length of the perforation is
preforably shorter than that of a regular impulse perforation, though it may be
equal to these without departure from the purpose for which it is designed.
This is illustrated in Fig. 5, in which a tape perforated to produce the same
signals as in the former figure is shown at T3. The final perforation for each letter
is seen to be somewhat elongated. The record which such a tape would produce
in the recording instrument of Fig. 1 is shown in the same figure at T, where, it
will be observed, there are no lines or marks shown between the successive letters
of a word, but a space mark appears between words. The prolonged contact of the
transmitter in passing over the final perforation holds the recorder out of
action during such period of contact which is sufficient to indicate clearly a
letter space. T, in Figure 5, indicates by the marks thereon the current impulses
as they actually pass over the line.
In lieu of elongating the final perforation, the same result may be secured by
making two independent perforations. side by side and very close together, as
shown in Fig. 6. The final perforation in this case is composed of two holes so
close together that their effect is the same as one long one, but as a partial
discharge of the line occurs between them the static effect is not so great.
In order to provide for clearing the line after each impulse sent by a perforated
strip, by directing into it a current of opposite direction to the marking current,
and at the same time avoid the difficulties which arise from the too prolonged
action of such clearing current, the apparatus shown in Fig. 3 is employed.
In this figure the transmitter proper is the same as in Fig. 2, but is included in
and controls a local circuit containing an electro-maguet that operates a polo
changer of special character.
This device consists of a lever m pivoted to move between two stops m³, ml,
the latter of which is grounded and also connected with one pole of the clearing
battery Bu
The lever m carries a contact strip n which, by the movement of the
lever, is caused to slide over a triangular or tapering plate n' connected to line
and adjustable transversely to the strip n.
Connected with the short arm of lever m is a lever o with a bifurcated end
between which plays the contact making armature ol of the relay magnet . These
parts are so arranged that when the magnet is energized its armature leaves the
contact p of lever o and engages contact p¹ on the other branch or fork of said
lever. At the same time it turns the lever o on its pivot, and thereby imparts an
amplified movement to lever m. The effect of this is as follows: When the lever m
is turned so as to bring the strip n onto the plate n', the line battery B, one
pole of which is grounded, is connected through the armature o¹, the levers o and m,
strip n and plate n' with line. When the current in magnet l ceases, its armature
し
is retracted and comes over into contact with the stop on arm p, and as the
armature is in electrical connection with lever o through the metallic frame or by
a wire the first effect is to connect the clearing battery B to line, but this
continues only while the strip n is in connect with plate n¹, for, as soon as these
are out of contact by the movement of the levers o and m, the clearing battery is
disconnected from the line.
The relative duration of the periods of charging and discharging the line are
thus made unequal, the clearing current being sent only after contact of the
armature o¹ with stop p and until the separation of the strip n and plate n¹. By
a transverse adjustment of the plate n', the duration of contact between the strip n
and plate n¹ after the beginning of the impulse may be adjusted.
In practice it will be frequently found that it is a matter of great importance to
be able to regulate the duration of the periods of contact of the transmitter which
are directly determined by the perforations in the paper strip and which send the
impulses to line.
This may be accomplished in a very simple manner by cutting

page_text: the perforations in the paper of varying width so that, by a transverse adjustment of
the style or trailer, with reference to the paper, or conversely, the duration of
actual contact may be adjusted to meet the best requirements of working. This
is shown in Fig. 7.
Inasmuch as the duration of contact should be determined solely with reference
to its inception, the initial edge of the perforations is at right angles to the
line of the paper, while the opposite edge is inclined thereto, as shown.
Figs. 8 to 10 illustrate the form of apparatus which is used in practice for
preparing the perforated tape. The apparatus is provided with two keys for the
dash and dot respectively, and suitable spacing keys, all being designated by the
letter E. These keys are attached to right angle levers, F and when a key is
depressed the first effect is to close, through contacts E¹, the circuit of the
punching magnet E". The further movement of a key thrusts forward a bar F' with
which it is connected by a pin Fll working in a slot so as to afford a certain play
or lost motion, and a spring G which presses upon the end of bar F tonds
to maintain the pin at one end of the slot.
The forward movement of the bar F1 brings its end under a pivoted armature
lever G', which is operated by a magnet H in a local circuit controlled by a circuit
closer H on the armature lever of the punching magnet, and which maguot is
energized when the said lever has been attracted.
The lever G¹ carries a pawl G" that engages with the ratchet H" of the paper'
feed roller, and is retracted by a spring I operating, when so retracted, to turn
the ratchet wheel H through an are determined by the extent of angular motion
of the lever.
:
Each key E has a corresponding bar F, and the parts of these bars which are
brought under the lever G₁ are of different widths corresponding to the length of
feed which each key is designed to impart. The points of contact on the bars are
formed as notches into which the lever G¹ is forced by the magnet H, so as to
prevent the bars F1 from shifting longitudinally until the lever G₁ has been
retracted.
Upon depressing any given key, the corresponding bar F1 is thrust forward
before the armature lever G¹ comes down and limits its downward movement.
Then, when the key is raised and the circuits broken, the spring I retracts the
lever G¹ and feeds the paper through a space determined by the width of the
bar F¹. In order that those unfamiliar with the Morse alphabet may be enabled
to prepare the perforated strips, electro-magnets I¹ may be employed for depressing
the keys, and these magnet are controlled by circuit closing wheels released and
stopped by keys corresponding to, and designated by, the letters of the alphabet.
In Figure 10 one of these alphabetical keys is shown at K. When one of them
is depressed, it releases a disc L upon different parts of which rests the ends of
levers L, L². In the path of lever L' are projections which correspond
to, say, dots, while in the path of lever L² are similar projections corresponding to
dashes.
The levers L1, L2 are circuit closers which control the circuits of magnets I¹
under the dot and dash keys respectively, so that on each disc there will be arranged
one or more projections which will lift and depress the two levers L¹, L' in the
desired order for actuating the dot and dash keys. There will be in like manner
key N which closes the circuit for the word spacing magnet, and a key for letter
spacing which, by a switch N¹, may be connected with either of the letter spacing
keys, as may be desired.
a
The apparatus above described may be greatly varied in construction without
departing from the invention.
Heretofore signals have been produced in or by a telegraphic receiver both by
the closing of an open circuit and the breaking of a closed circuit. It is, moreover,
known that a perforated strip of substantially the kind herein described has been
employed as the means for operating a transmitter for sending impulses of the
usual character over the line, but the novel feature of the present invention is in

page_text: the operation of a line or circuit by impulses of uniform duration directed over it
at variable intervals and to a receiving or recording instrument, which indicates or
records all of the intervals between such impulses, but none of the impulses
themselves.
Having now particularly described and ascertained the nature of the said
invention 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 method of telegraphing herein described, which consists in transmitting
over a line electrical impulses of uniform duration at variable intervals and
indicating or recording at the receiving station the intervals between impulses or
the periods of no current on the line, as set forth.
2. The method of telegraphing herein described, which consists in transmitting
over a line electrical impulses of uniform duration at intervals corresponding to
the length of the elements of the characters and spaces of the Morse code, and
interrupting by such impulses the action or operation of an electro-magnetic
recording instrument, whereby the said instrument will produce marks or lines
during intervals between successive impulses only, or after such impulses have
ceased, as set forth.
3. In a telegraph system, the combination with a main line a transmitter and a
perforated strip for operating the same, provided with a single line of perforations
of uniform length but at variable intervals, which perforations determine the
periods of current on the line, of a recording instrument at the receiving end
of the line operated or controlled by the transmitted impulses and adapted in
its operation to record the intervals between such impulses, as set forth.
1. A perforated strip or band for telegraphic transmitters in which the
perforations have their initial edges at right angles to the length of the strip,
and their opposite edges inclined thereto, whereby the duration of the periods
of contact of a style under which the strip is drawn may be varied or adjusted
by a transverse adjustment by the style with reference to the line of movement
of the strip, as set forth.
5. In a telegraph system the combination with an instrument adapted to
make and break an electric circuit by means of a perforated strip, of an instrument
contolled or operated thereby and adapted to transmit over the line two
immediately successive alternating impulses corresponding to each of the
unidirectional impulses produced by the passage of the trailer over the perforated
strip, as set forth.
6. The combination in a perforating apparatus for automatic telegraphy, of
a paper punch and feed mechanism for the paper, and a ratchet connected with
the feed mechanism, a lever and pawl engaging with the ratchet, a series of
keys, all of which, when depressed, operate the punch and the feed mechanism,
and a series of bars of varying widths connected with the keys and adapted to
be interposed by the depression of the latter in the path of the lever of the
feed mechanism, whereby the extent of play or angular movement of said lever
will be different for different keys, as set forth.
7. In a perforating mechanism for electric telegraphy, the combination with
a single die or punch, of a series of perforator keys, all of which operate, when
depressed, to actuate the punch, and each of which, when depressed, imparts a
movement of different extent to the paper, of a series of keys corresponding to
letters and characters, automatic circuit closers adapted to be set in motion by
the operation of said letter keys, electro-magnets for operating the perforator
keys and circuit connections between the automatic circuit closers and said electro-
magnets whereby the depression of a letter or figure key sets in motion its
corresponding circuit closer, causing it to operate one or more of said perforator
keys in the order necessary for producing the perforations and spaces corresponding
to the letter or character of the key depressed, as set forth.
8. In a perforating machine, the combination of a feeding mechanism for the

page_text: strip, and punch or die, an electro-magnet for operating the punch, a series of keys
or levers controlling circuits which include the said electro-magnet, a series of
electro-magnets which operate the said keys or levers, a series of automatic circuit
closers which control the circuits in which the last said magnets are situated, and
a series of keys corresponding to letters or figures and arranged to control the
movements of the said circuit closers, substantially as set forth.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, W.C., Agents for the Applicant.