Improvements in Telegraphic Apparatus.
Year: 1899

page_text: Improvements in Telegraphic Apparatus.
We, ALBERT CUSHING CREIORE, 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 apparatus for telegraphing through circuits com-
prising wires or cables possessing considerable electrostatic capacity.
In such circuits successive impulses in the same direction frequently lead to
apiling up of the charge within the cable so that at the receiving end a
succession of impulses in one direction is recorded as a line that rises (i.e.,
moves further from the neutral line) with additional impulses.
The objects of this invention are first to improve the character of the signals
by preventing or diminishing the rising of the line recorded so as to render
the deciphering of the record easier, and secondly to lessen the charge in the
cable that has to be got rid of by earthing or otherwise.
For these purposes and according to this invention we provide means for
diminishing the electromotive force of the signalling current in the case of
impulses subsequent to the first when two or more are sent consecutively in the
same direction.
In the case of an automatic transmitter the desired effect may be obtained by
means of a suitable device adapted, on the presence of two or more perforations
in immediate succession in the same row of the tapé, to introduce an impedence
(as a simple resistance, an inductional device, à counter-electromotive force
apparatus, or an electrostatic capacity, or a combination of two or more of
these) during the second and following impulses in such a manner as to reduce
the voltage upon the line.
In the case of automatic transmitting apparatus in which current passes
through the perforations of the tape, there may according to this invention · be
provided for each row of perforations two upper contacts and a lower contact or
pair of contacts electrically connected together, of which the upper contacts are
so arranged that contact can be made simultaneously by both of the upper con-
tacts through two perforations one immediately after the other in the same row,
and a separate scurce of current is used for each such lower contact or pair of
contacts. The two upper contacts of each row of perforations are made parts of
a circuit which serves to introduce electromagnetically an impedence such as
hereinbefore mentioned into the line or otherwise to decrease the electromotive
force of the signalling current whenever two or more consecutive perforations in
the same row allow connexion to be made between the contacts over such row.
There may be an electromagnetic contact device for each circuit or a single
electromagnetic contact device may suffice for both circuits and be provided
either with an electromagnet-for-each-circuit-or-with-a-double-wound electro-
magnet. Such an arrangement may be used in the case of transmitting
apparatus such as described in the Specifications of Letters Patent No. 6787 of

page_text: 1897 and of Applications for Letters Patent No. 23,556 of 1898, and No. 4931 of
1899, and in the Specifications of Letters Patent No. 21,630 and No. 23,687
of 1893.
In the case of transmitting apparatus of the kind described in the aforesaid
specifications, we sometimes provide mechanism arranged to be operated by the
armatures of electromagnets (for example the transmitter magnets of apparatus
such as described in the Specifications of Letters Patent No. 21,630
and No. 23,687 of 1893) so as to introduce the impedence only in the case of two
or more strokes in the same direction as required.
In the case of transmitting apparatus in which current does not pass through
the perforations of the tape but the required contacts are made by means of levers
there are provided for each row of perforations two levers (one for making the
contact as usual) adapted to engage in two perforations one immediately follow-
ing the other in the row and so connected that on engaging in two such per-
forations they will complete a circuit so as to introduce the impedence as
required.
The impedence may be introduced in one or more of several places so as to
reduce the voltage as required for instance, in series with the line, in shunt
around the generator, or in the field circuit of the generator.
In some cases devices according to this invention may be entirely independent
of the transmitters and be included in the signalling circuit between the trans-
mitters and the like.
Improvements in 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 an apparatus for telegraphing through circuits com-
prising wires or cables possessing considerable electrostatic capacity.
In such circuits successive impulses in the same direction frequently lead to
a "piling up" of the charge within the cable so that at the receiving end a
succession of impulses in one direction is recorded by a line that rises (i.e.
moves further from the neutral line) with additional impulses.
The objects of this invention are first to improve the character of the signals
by preventing or diminishing the rising of the line recorded so as to render
the deciphering of the record easier, and, secondly to lessen the charge in the
cable that has to be got rid of by earthing or otherwise.
The further object of the invention is to accomplish this result without
changing the number or disposition of the perforations or indentations in the
tape of the automatic transmitter heretofore employed.
To this end, we propose to provide the automatic transmitter with a suitable
device whereby on the presence of two or more holes in immediate succession

page_text: in the same row of tape, the action of the apparatus controlled by said transmitter
shall be so modified or changed as to-prevent these perforations or indentations
which succeeded the first from impressing the full E.M.F. of the generator upon
the line.
This modification in the impression of the E.M.F. may consist of a greater or
less lowering of the E:M.F. or a total suppression thereof, or other change which
will prevent the difficulty above named, and may be produced by introducing
impedance, as for instance, by a simple resistance, an inductional device, counter-
electromotive force apparatus or an electrostatic capacity, or a combination of
two or more of these on the occurrence of the one or more perforations succeeding
the first in the transmitting tape. Or, the modification may be produced by
simply opening the circuit of the generator when otherwise it would have been
closed by the second and succeeding ones of the perforations, or may be produced
by shunting the current of the generator from the line.
In the case of automatic transmitting apparatus in which the transmissions are
effected by a tape having transmitter brushes or fingers bearing upon the tape,
we propose to provide supplemental pilot or feeler brushes or fingers in addition
to those provided in the ordinary forms of apparatus, such pilot or feeler brushes
operating upon or in conjunction with devices whereby the action of the apparatus
in transmitting the signals will be modified when two or more perforations succeed
one another in the same line, and thereby prevent the second and following
perforations from impressing the full E.M.F. of the generator upon the circuit.
When the tape has two rows of perforations a supplemental feeler or pilot con-
tact or finger would be provided for each row.
The modification in the operation of the apparatus controlled by the tape may
be secured through the action of electro-magnets in circuits including the
supplemental pilot or feeler brushes, said electro-magnets controlling suitable
contacts which will shunt an impedance into the circuit or open the circuit,
or shunt the generator, or otherwise control the impression of E.M.F. upon the
circuit. Instead of electromagnets, devices acting by purely mechanical operation
to close or open the circuits may be employed.
Our invention may be used for perforated tape transmitting apparatus such as
described in the specification of British Letters Patent No. 23,556 of 1898,
No. 4931 of 1899, and No. 21,630 and No. 23,687 of 1893.
The figures of the drawing illustrate diagrammatically, and by way of example,
apparatus operating in accordance with our invention. 1 and 2, represent the
transmitter brushes for the dots and dashes respectively, said brushes being
arranged to bear upon different longitudinal rows of perforations in a tape. 3
and 4, are the electromagnets, by means of which the brushes when they fall
into the perforations operate the tongues 5 and 6, which are normally kept by
their springs at 7 and 8 in contact with a bar 9, so as to connect the cable C,
to earth E. and which cause currents to be sent in the required direction when
The bars 9 and 10, connect
respectively brought into contact with the bar 10.
respectively with the opposite poles of the source of electricity S. This source
may be, as described in the specifications of the patents above referred to, and as
shown more particularly in Figs. 3 and 4 of the accompanying drawings, an
armature of a dynamo machine which revolves in a suitable field and has its
terminals connected to the two halves of a commutator upon which bear brushes
connected respectively to the bars 9 and 10.
Separate lower contacts 1ª, 2a, are provided for the brushes 1 and 2 respectively
and for separate local batteries 1b, 2b respectively.
The supplemental pilot or feeler brushes are indicated at I, and II. They serve
to reduce the electromotive force applied to the cable C, by introducing the
impedance 11 into the circuit when the second of two perforations, one immediately
following the other, allows current to pass through either_of_the-brushes-1-
and 2. The source of current-S-is-connected to the bar 9 through a tongue 12
which is normally kept against a stop 13 by a spring 14. The brush I is con-

page_text: nected through-a battery I with an electromagnet Ib, which is likewise connected
to the brush 1; the brushes II and 2 are similarly connected through a battery IIª
and an electromagnet II'. Whenever two perforations occur in succession in
the row passing under the brushes 1 and I, the circuit of the battery I will be
closed through said brushes and the plate Iª: similarly the circuit of the battery
II will be closed by the brushes 2 and II. Both of the electromagnets I and IIb
are adapted to operate the tongue 12 so that when either of them is energized
it attracts the tongue 12 to a stop 15 so as to include the impedance 11 in the
connection between the source of electricity S and the bar 9.
In the case of transmitting apparatus of the kind described in the aforesaid
specifications, we sometimes provide mechanism arranged to be operated by the
armatures of electromagnets, (for example, the transmitter magnets of apparatus
such as described in the Specifications of Letters Patent No. 21,630 and No. 23,637
of 1893) so as to introduce the impedance only in the case of two or more strokes
in the same direction as required.
In the case of transmitting apparatus in which current does not pass through
the holes of the tape but the required contacts are made by means of levers,
allowed to operate as required by the holes in the tape there are provided for
each row of perforations two levers (one for making the connection between the
line and the source of current as usual) adapted to enter two holes one immediately
following the other in the row and provided with such a connection that on
engaging in two such holes they will complete a circuit so as to introduce
the impedance as required.
Fig. 2 is a diagram showing the arrangement and connections of two such
levers for the row of holes for transmitting dots: 1° is an ordinary trans-
mitting lever, 1b its local battery, and 3 the electromagnet energized thereby for
completing the circuit between the line and the source of electricity; I° is
the additional pilot or feeler lever adapted to enter the first of two holes, one
immediately succeeding the other, when the second thereof is entered by the
lever 1; Ib is the electromagnet for actuating the tongue of the impedance as
in the case of Fig. 1, and I₁ its battery; 16 is a bar adapted to connect the
two levers 1 and I and thereby to close the circuit of the electromagnet Ib when
the levers 1 and I° enter two holes one immediately succeeding the other in
the tape.
An impedance may be introduced as hereinbefore described in one or more
of several places so as to reduce the voltage as required-for instance, in series
with the line, in shunt around the generator, or in the field circuit of the
generator.
Fig. 3 shows how the current of the generator may be shunted so as to cut
down or practically suppress the E.M.F. which would otherwise be applied to
the circuit. As shown, the armature 12 is connected with the resistance or
impedance 11 in shunt or branch across the connections leading from the generator
to the bars 9, 10, so that whenever either of the magnets Ib, IIb, is operated the
current will be shunted through 11.
Fig. 4 shows how the armature might be made to open the circuit of the
generator when a second perforation passes under the transmitting stylus 1 or 2.
It is obvious that in some cases the modification of the action may be produced
by devices included in the signalling circuit between the transmitter and the
line, thus for instance, instead of locating the armature 12 in the position shown
in Fig. 4, it might be placed between the tongue 5 and the line."
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. Telegraphic apparatus in which the electromotive force of the signalling
current is modified in the manner described in the case of impulses subsequent
to the first when two or more are sent in consecutively in the same direction.

page_text: 2. In telegraphic apparatus, the combination with an automatic transmitter, of
means whereby, on the presence of two or more holes in immediate succession in
the same row of the tape, the voltage upon the line will be reduced or cut off,
as and for the purpose described.
3. Telegraphic apparatus comprising an automatic transmitter, in which two
contacts are arranged for each row of perforations in the tape, to make contact
simultaneously with a single contact (or pair of electrically connected contacts)
through two perforations one immediately following the other in the same row,
and the contact so made serves to introduce electromagnetically an impedance
or otherwise to decrease the electromotive of the signalling current, substantially
as described.
4. In telegraphic apparatus, means for introducing an impedance for the
purpose mentioned constructed, arranged, and operating substantially as herein-
before described and illustrated diagrammatically in Fig. 1 of the accompanying
drawings.
5. In telegraphic apparatus comprising an automatic transmitter in which the
contacts are made by means of levers and not through perforations in the tape,
the provision of an extra lever for each row of holes so arranged that it and
the transmitting lever will simultaneously enter two holes one of which immedi-
ately follows the other, and an electric circuit that will, on such entry, be com-
pleted and introduce an impedance for the purpose stated, substantially as
described and illustrated diagrammatically in Fig. 2 of the accompanying
drawings.
6. In telegraphic apparatus, the provision of mechanism arranged to be operated
by the armatures of electromagnets so as to introduce an impedance or otherwise
to reduce the electromotive force of the signalling current only in the case of
two or more strokes in the same direction.
7. Telegraphic apparatus in which the action is modified in the manner
described to prevent the full E.M.F. of the generator from being impressed upon
the circuit upon the occurrence of two or more perforations in the transmitting
tape in immediate succession.
8. In automatic telegraphic apparatus supplemental pilot or feeler brushes or
fingers operating in conjunction with devices as described to prevent succeeding
perforations after the first from impressing the full E.M.F. of the generator upon
the circuit.