Improvements in or connected with Telegraphic Apparatus.
Year: 1899

page_text: Date of Application, 3rd Oct., 1899
Complete Specification Left, 3rd July, 1900-Accepted, 3rd Oct., 1900 i
PROVISIONAL SPECIFICATION.
Improvements in or connected with Telegraphic Apparatus.
We, ALBERT CUSHING CREHORE, of Hanover, Grafton County, State of New
Hampshire, United States of America, Professor of Physics, and GEORGE OWEN
SQUIER, of Washington, District of Columbia, United States of America, Captain
in the United States Army, do hereby declare the nature of this invention to be as
follows:
=:
This invention relates to telegraphic apparatus for imparting to a line or cable
waves or pulsations of current each of which rises gradually and continuously to a
maximum and falls gradually and continuously to a minimum.
According to this invention there is combined with means for supplying either
a single alternating current or a unidirectional pulsating current, an auto-
matic transmitter which comprises or is provided with a reversing device adapted
to be controlled by the perforations or indentations of the tape and whose tape
is perforated or indented and moved in such a manner that the contact closures
produced thereby synchronize with the waves or pulsations of the current
supplied.
The means for supplying the current may be of any suitable kind-for example,
a dynamo, or a battery with a suitable impedance-varying device, which may
supply waves that are sinusoidal or approximately so-the dynamo may, more-
over, be adapted, as by the displacing of its brushes from the neutral position,
to allow a small curbing impulse of contrary direction to follow each of the
signalling impulses; the impedance-varying device may be likewise adapted to
perform the same function.
The feeding of the tape in synchronism with the waves or pulsations of
current may be effected by means of a suitable mechanical connexion between the
feeding device acting on the tape and the rotary part of the dynamo or an equiva-
lent part of the impedance-varying device in the case of a battery. The feeding
of the tape may also be effected by the current generated, by electrical means,
as a synchronous motor.
The automatic transmitter may have either a suitable electro-mechanical
reversing device for example as described in the Patent Specifications numbered
21,630 and 23,687 of the year 1893 or a purely mechanical reversing device (for
example, one of the Wheatstone type).
The tape used in apparatus according to this invention must be provided
with perforations or indentations so arranged in relation to one another as to
cause waves or pulsations of current to pass through the line or cable in the
directions required.
The arrangement of the perforations or indentations for an alternating current
may differ from that for a pulsating current in such a manner that if the same
message have to be transmitted by two apparatus of which one uses an alternating
current and the other a pulsating current, alternate perforations or indentations
(each corresponding to a single impulse) for the former will be the reverse of the
corresponding ones for the latter.
For preparing tapes for use in alternating-current apparatus according to this

page_text: invention, the perforating or indenting apparatus may be such that at each
feed the electrical or mechanical connexions between the two signal-punch keys
and the corresponding punches will be reversed, so that ordinary manipulations
of the keys will produce tapes prepared as required and it consequently will not
be necessary for the operators to fearn any new mode of manipulation.
Improvements in or connected with Telegraphic Apparatus.
We, ALBERT CUSHING CREHORE, formerly of Hanover, .Grafton County, State
of New Hampshire, United States of America, but now of Tarrytown, West-
chester County, State of New York, United States of America, Electrician, and
GEORGE OWEN SQUIER, of Washington, District of Columbia, United States of
America, Captain in the United States Army, 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 telegraphic apparatus for imparting to a line or cable
pulsations of current each of which rises gradually and continuously to a
maximum and falls gradually and continuously to a minimum.
According to this invention there is combined with means for supplying either
a single alternating current or a single unidirectional pulsating current, an auto-
matic transmitter which comprises or is provided with a reversing device adapted
to be controlled by the perforations or indentations of the tape and whose tape
is perforated or indented and moved in such a manner that the contact closures
produced thereby synchronize with waves or pulsations of the current supplied.
The means for supplying the current may be of any suitable kind-for example,
a dynamo, or a battery with a suitable impedance-varying device, which preferably
supply waves that are sinusoidal or approximately so-the dynamo may, more-
over, be adapted, as by the displacing of its brushes from the neutral position,
to allow a small curbing impulse of contrary direction to follow each of the
signalling impulses; the impedance-varying device may be likewise adapted to
perform the same function.
The feeding of the tape in synchronism with the waves or the pulsations of
current may be effected by means of a suitable mechanical connexion between the
feeding device acting on the tape and the rotary part of the dynamo or an equiva-
lent part of the impedance-varying device in the case of a battery. The feeding
of the tape may also be effected by the current generator, by electrical means,
as a synchronous motor.
The automatic transmitter may have either a suitable electro-mechanical
reversing device-for example as described in the Patent Specifications numbered
21.630 and 23,687 of the year 1893-or a purely mechanical reversing device (for
example, one of the Wheatstone type).."
An example of apparatus according to this invention for utilizing a single
unidirectional pulsating current is represented in Fig. 1 of the accompanying
drawings. The pulsating current is supplied by a two-pole dynamo D whose
commutator brushes are connected by leads L and L with the two bars B and B¹
of a reversing device R of the kind described in the aforesaid Specifications and
comprising two tongues M and M¹ permanently connected to the line or cable C

page_text: and the earth or other return E respectively, and, in the absence of current, both
kept by springs S and S¹ against the bar B. The tongues M and M' are under
the action of electromagnets H and H whose coils are connected on the one
hand to the brushes A and A¹ respectively of the transmitting tape T, and on
the other hand through a common local battery J to the common contact cylinder F
of the brushes A and A¹. In order to cause the tape T to move in such manner
that the contact closures of the brushes A and A', and consequently those pro-
duced by the magnets H and H of the reversing device R, synchronize with
pulsations of current supplied, the feeding pinion P, which engages in the feed
holes of the tape, is connected with the shaft of the dynamo by means of two
toothed wheels G and G¹ fixed respectively on the dynamo shaft and the shaft
of the pinion P. To produce the desired effect the gear ratio and the number
of feeding pins must be such that the tape T advances a distance equal to the
distance between the centres of successive feed holes during the generation of
a single pulsation or semi wave of electromotive force; the dynamo having two
poles, this result will be produced if the pinion G have twelve teeth, the wheel G¹
ninety six teeth, and the feeding pinion P sixteen pins. The diameter of the
holes in ne tape for the dots and the dashes (which, as is usual in cable
telegraphy, are represented by holes on opposite sides of the tape) should be a
trifle greater than the distance from centre to centre of consecutive feed holes
so as to make allowance for the thickness of the wires of the brushes, and for
the thickness of the tape, and thereby to insure that each contact closure will
last during a complete semi-wave of electromotive force. To secure the coin-
cidence of the contact closures with the generation of semi-waves, the brushes A
and A and their contact cylinder F should be capable of adjustment along the
tape towards and away from the feeding pinion P. For this purpose they may
be mounted upon a carriage that can be adjusted along the tape by means of a
micrometer screw, as described in the Specifications of Letters Patent No. 4931
of 1899. It will be seen that when no current is passing through either of the
electromagnets H and H', their tongues M and MI connect the line or cable C
directly to the earth or other return E through the bar B. If, however, either
of the tongues is drawn over the bar B¹ by its electromagnet owing to contact
made by the corresponding brush with the cylinder F, then the two tongues
are in contact with opposite bars, and the circuit from line to earth is no longer
completed through one of the bars, but now includes the armature of the gene-
rator D. When the brush A comes into contact with the cylinder F the tongue M
is attracted to the bar B, and when the brush A¹ passes through a perforation
in the tape T the tongue M¹ is attracted thereto; consequently pulsations of
current will be sent through the line or cable in opposite directions to represent
dots and dashes, as determined by perforations arranged in the tape in the ordinary
way.
Fig. 2 illustrates diagrammatically an example of apparatus according to this
invention in which a single alternating current is employed. D is a dynamo
furnishing alternating electromotive forces through the leads L and L' to the
bars B and B of a reversing device R', which is controlled by the perforations
in the tape T by means of two polarized relays I and I. Each of these relays
has two independent coils. Two of the coils, one in each relay, are connected
in series with the bars B and B so as to be continuously traversed by the alternat-
ing current, which consequently continually vibrates the tongues M and M' of
the relays from the bar B to the bar B1 and vice versa. In the connexion between
the two coils there is an impedance V for the purpose of adjusting the phase
of the current passing through the coils and so regulating the periods of contact
of the tongues M and M. The coils are so connected that a positive pulsation
brings both tongues into contact with the bar B, whilst a negative pulsation
changes both tongues simultaneously to the bar B'. The line is thus continually
connected to earth through either the bar B or the bar B₁ and no impulse is sent
to line by this circuit. The other coils of the relays I and I receive from the
•

page_text: local battery J current that is controlled by the perforations in the tape. A
reversing device for this battery current is made to operate in synchronism with
the generator D¹. For this purpose, in the example, a commutator K is provided
on the shaft of the alternator D, and the battery current is supplied continuously
through brushes X and Z to its two parts from which brushes W and Y take
off a periodically reversed current, which passes from Y to Y', and there divides,
a branch passing around a coil in each of the two polarized relays I and I', and
thence to the two brushes A and A¹ that bear upon the tape T; the other brush W
of the commutator is connected to the contact cylinder F of the tape, so that
the battery circuit is completed whenever a perforation occurs in the tape. The
perforations in the tape are, of course, so arranged that contact is never made
through both brushes A and A at the same time, and consequently only one
relay I or I', can be affected by the battery current at one time. The power of
the battery current is made greater than that of the alternating current through B
V, and B', so that the battery current alone controls the tongue M or M of the
relay, I or II, through which the current happens to pass. The relay coils
traversed by the battery current are so wound that at each instant the battery,
if one of its circuits were closed, would have a directly opposite effect to that
of the alternating current passing through the relays, so that whenever a battery
current flows through a relay coil the armatures M and M¹ bear against both of
the bars B and B31 instead of against only one and consequently an impulse from
the dynamo passes to line. Furthermore, impulses of one sign pass to line as
long as contact is made by one of the tape brushes, A for example, and of the
opposite sign when the other brush, A', is in contact, as is evident from the follow-
ing. Suppose, for example, that the tongues M and M¹ are both normally in
contact with the bar B while a positive impulse is being generated by the
dynamo D¹, and with the bar B1 during a negative impulse. Suppose that a
current through the local circuit in the direction Y Y'A W has the effect of
moving the tongue M into contact with the bar B', then a positive impulse will
go to line from the generator D'. In one half a revolution of the generator_a
negative electromotive force will begin, which will tend to bring both tongues M
and M into contact with the other bar B, so that the tongue M¹ will make
contact with the bar B owing to the alternating current passing through the
relay but at the same time the tongue M will reverse and come into contact
with the bar B because the current in the local circuit will also have reversed
owing to the action of the reversing commutator K. A negative impulse is now
being generated by the generator D' but a positive impulse goes to line because
the device is now reversed. Similarly positive impulses will pass successively
to line as long as the brush A makes contact with the cylinder 1. If the brush A¹
make contact, negative impulses will similarly pass to line. Positive and nega-
tive impulses can therefore be sent to line as required by means of a tape per-
forated in an ordinary manner as in the case of pulsating currents described with
reference to Fig. 1.
Fig. 3 represents the apparatus shown in Fig. 2 modified to obviate the use
of the battery reversing device. In this case the gear connecting the shaft of
the dynamo D¹ to the tape T is so proportioned that the distance between centres
of consecutive feed holes in the tape corresponds to a whole wave of the generator
consisting of a positive and a negative portion, instead of a single pulsation or
semi-wave. If a succession of holes occurs in the tape under the brush A, for
example, the battery current holds the tongue M in continuous contact with the
bar B for example. The other tongue M¹ is simultaneously vibrating to and fro
between the bars B and B when the tongue M¹ is in contact with the bar B¹
the line is connected to the earth or other return and when in contact with the
bar B a positive impulse is transmitted to line. Thus a series of positive impulses
is transmitted as long as the brush A makes contact, successive impulses being
separated by equal periods in which the line is connected to the earth or other
return. Similarly a series of negative impulses goes to line when the brush A¹

page_text: makes contact, these impulses being likewise separated by equal periods in which
the line is connected to the earth or other return. The transmitted pulses are
as shown in Fig. 4 in the case of the apparatus shown in Fig. 3, instead of as
shown in Fig. 5, which represents a series of impulses of the same sign imparted
by the apparatus represented in Figs. 1 and 2. Signals transmitted in either of
these ways can operate a siphon recorder well.
Figs. and show other means for supplying the pulsating or alternating
currents, which may be substituted for the dynamos D and D. Fig. 6 repre-
sents a device in, which the terminals of a source 1 of constant electromotive
force, as a battery, are connected to an impedance coil N which is connected at
its ends by wires Q and Q12 to two terminals q and q12 and at equal intermediate
intervals by wires Q'
Q to pairs of terminals q', q³ . . . . q.
The terminals 9, 9¹
qare arranged in a circle so that a revolving arm U
carrying a trailing brush will come successively into contact with the several
terminals q, g¹.
18 in a revolution. The arm U is fixed on a shaft O
which is driven at a constant rate by a source of power, and the leads L and L¹
which are attached to the terminals 12 and the shaft respectively, are therefore
supplied with a pulsating electromotive force rising from zero to a maximum
and returning to zero during each complete revolution of the arm U This device
may therefore be substituted for the generator D of Fig. 1. The pinion P for
feedin the tape will then be connected by gearing with the shaft 0, but the gear
ratio should differ from that described with reference to Fig. 1 by a factor of two
since one revolution of the dynamo shaft makes two semi-waves, whilst the arm
produces only one semi-wave per revolution. The device shown in Fig. 6 may,
however, be easily modified so as to make as many waves per revolution as desired.
An obvious modification of the device shown in Fig. 6 is to omit, the source of
electromotive force 1 and to substitute for the coil N battery cells connected in
series, which would then be joined by the leads Q
Q12 to the
terminals q
q Fig. 7 represents a further modification of the device
shown in Fig. 6 to adapt it for supplying an alternating current, the lead L
being connected to the middle pair of terminals q; in this case also the source 1
might be omitted and battery cells substituted for the coil N.
Fig. 8 represents means by which the synchronous feeding of the tape T can
be effected electrically when it is preferred to generate the electricity at a distance
from the tape too great to allow of the direct mechanical connection herein before
described. The generator D₁ is in this case an alternator and its brushes are
connected by a lead and the earth respectively with the brushes of a synchronous
motor D2, whose shaft consequently revolves in synchronism with that of the
distant generator D. The shaft of the synchronous motor D2 is connected with
the feeding pinion P by means of gearing as shown in Fig. 1. If it be desired
to supply pulsating current to the leads L and L¹ the shaft of the motor ])*
carries a a rectifier K¹ which is so connected by leads and with the gene-
rator D and the earth or other return respectively, and has the brushes for
the leads Land L₁ so arranged that when the lead L is connected with the
generator D through the leads and the lead L¹ is connected to the earth or
other return through the lead and vice versa. When it is desired to supply
the leads L and L' with alternating current, the rectifier K¹ is omitted, the lead L
being connected directly to the lead and the lead L¹ to the earth or other return
to the generator D¹. It is obvious that a device such as shown in Fig. 7 may be
substituted for the dynamo D¹.
The tape used in apparatus according to this invention must be provided with
perforations or indentations so arranged in relation to one another as to cause
pulsations of current to pass through the line or cable in the directions required.
The arrangement of the perforations or indentations for an alternating current
may differ from that for a pulsating current in such a manner that if the same
message have to be transmitted by two apparatus of which one uses an alternating
current and the other a pulsating current, alternate perforations or indentations

page_text: (each corresponding to a single impulse) for the former will be the reverse of the
corresponding ones for the latter-i.e., if an alternate perforation or indentation
be in the right hand row for the alternating-current apparatus the corresponding
perforation or indentation for the pulsating-current apparatus will be in the left-
hand row, and vice versa.
For preparing tapes for use in alternating-current apparatus according to this
invention, the perforating or indenting apparatus may be such that at each
feed the electrical or mechanical connections between the two signal punch keys
and the corresponding punches will be reversed, so that ordinary manipulations
of the keys will produce tapes prepared as required and it consequently will not
be necessary for the operators to learn any new mode of manipulation."
Although in the examples described the control of the reversing device of the
transmitter is effected by the passage of current through perforations in the tape,
it is obvious that the control could be effected by indentations in lieu of the
perforations, the circuits of the local battery being then completed as required
in a known manner by levers adapted to enter such indentations. Such a lever
arrangement might also, of course, be used for a perforated tape.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed we declare that what
we claim is:
1. In telegraphic apparatus, the combination with means for supplying either
a single alternating current or a single unidirectional pulsating current, of an
automatic transmitter which comprises or is provided with a reversing device
adapted to be controlled by the perforations or indentations of the tape and whose
tape is perforated and moved in such a manner that the contact closures produced
thereby synchronize with waves or pulsations of the current supplied, substantially
as and for the purpose set forth.
2. For supplying a unidirectional pulsating current or an alternating current
to a telegraphic line or cable, the combination of a battery or other source of
constant electromotive force and an impedance-varying device, or as modifications
thereof, the combination of battery cells in series with means for varying the
number of cells in circuit, substantially as described with reference to Figs. 6
and respectively of the accompanying drawings.
3. For feeding a telegraphic transmitting tape in synchronism with waves or
pulsations of alternating current, the combination with the generator of alternat-
ing current of a synchronous motor actuated by the said current, substantially
as described with reference to Fig. 8 of the accompanying drawings.
4. The improved telegraphic transmitting apparatus constructed, arranged,
and operating as hereinbefore described with reference to and shown respectively
in Fig. 1, in Fig. 2, and in Fig. 3 of the accompanying drawings, and the same
as modified as described with reference to and shown respectively in Fig. 6,
in Fig. 7, and in Fig. S thereof
5. In telegraphic apparatus comprising a generator for supplying to a line
or cable current impulses each of which rises gradually and continuously to a
maximum and falls gradually and continuously to a minimum, the adaptation of
the generator to furnish a small curbing impulse of contrary direction after each
of the aforesaid impulses. substantially as described.
T
1000
Dated this Brd day of July 1900
For the Applicant
W. LLOYD WISE.
46, Lincoln's Inn Fields, London, W.C.,
Chartered Patent Agent.