A NEW ELECTRO-TELEGRAPHIC SYSTEM PARTICULARLY APPLICABLE FOR LONG CABLES
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by Augusto Guattari at the Office of
the Commissioners of Patents on the 24th August 1883.
r
AUGUSTO GUATTARI, of Paddington in the County of Middlesex, "A NEW
ELECTRO-TELEGRAPHIC SYSTEM PARTICULARLY APPLICABLE FOR LONG CABLES."
This Invention relates to a new electro telegraphic system particularly applicable
to long submarine cables, but also applicable for land lines, and it has for its object
to produce at any distance a mechanical movement of sufficient energy and ampli-
tude to set in motion any suitable kind of printing telegraphic instrument, without
the line current having to produce any mechanical movement neither galvano-
scopically nor electromagnetically by attraction or by neutralisation, so that however
feeble may be the current, and however short its duration, the desired effect shall
nevertheless be inevitably and instantaneously produced.
In order that the Invention may be more readily understood, I have illustrated
one example of the means of carrying the Invention into effect and will proceed to
describe it with reference to the drawings.
A is a flat thin soft iron blade or pallet mounted on an axis a (Figures 1 and 2)
so as to oscillate freely in the direction of its width.
It is surrounded as closely as possible by a very long and fine coil B (which for
convenience is divided into two portions) so that the pallet will be polarized by a
very weak current traversing the coil, which is placed in the circuit of the line
wire.
The ends of the pallet project a short distance beyond the coil, and two spring-
actuated levers c of brass, tend to bring the pallet to its central position, their
action being limited by a stop. The lower end of the pallet plays between the
poles of an electro magnet E the pallet when in its central position being midway
between the said poles.
The pallet in oscillating approaches as closely as possible to the poles without
however touching them (unless through the interposition of a thin piece of non-
magnetic material) its motion being controlled by suitable adjustments. The other
end of the pallet terminates in a pin e which engages in the end of an escapement
Jever F pivoted at f whose other end is forked or otherwise adapted to engage
with the printing mechanism whose motion is to be controlled. The pin also
engages in the slot of a cam wheel g upon a shaft mounted in the plane of
oscillation of the pallet, and geared directly with the printing mechanism the office
of the cam being to complete the oscillation of the pallet. Upon this shaft is also

page_text: mounted a commutator C, whose function is to reverse the current in the line wire
at each half revolution of the shaft.
In the diagram figure 6 No. 1 is the transmitting and No. 2 the receiving
apparatus which are similar except that in the latter the commutator is out of
circuit. The coils B are in the circuit of the line wire L, which is traversed by the
current of a weak battery p (such as used on long submarine cables) at the
transmitting end, the current passing through the commutator C.
The electro-magnet E both of the transmitting and receiving instrument is
traversed by the current of a powerful local battery P. Under these conditions
the pallet of each apparatus will assume the position due to its polarization
relatively to the poles of the electromagnet E.
The apparatus is manipulated by closing a derivation (without resistance) G of
the said circuit, or by breaking the circuit of the local battery. The effect of this
interruption or derivation of however short duration will be to weaken the electro-
magnet, and permit of the pallet being returned by the spring acting on it, to the
central position.
The printing apparatus is then released from the escapement lever F, the cam
makes a half revolution and completes the oscillation of the pallet, at the same
time that the motion of the commutator reverses the direction of the current-in
the coil B, and consequently reverses the polarity of the pallet, and the local
current being reestablished through the electro-magnet E the latter retains the
pallet in its new position. At the next interruption or derivation of the local
battery current the pallet is moved in the reverse direction.
The action at the receiving end is similar, that is to say at each inversion of the
line current in coil B the polarity of the pallet is reversed, and it is no longer
retained but on the contrary repelled by the pole of the electro-magnet to which it
previously adhered, and is moved away by the spring.
The pallet is made thin so as to be influenced throughout its mass and wide so
as to offer a large surface to the action of the coil, and it is of considerable length
so that its poles are perfectly distinct, the conditions being such that the least
current passing through coil B for the shortest possible time, and of an intensity
not susceptible of being measured; like the current which is established instanta-
neously in long submarine cables, suffices to change the polarity of the pallet, and
bence to work the apparatus. The speed of transmission resulting from the
instantaneous utilization of the current is still farther favored by the fact that the
current is alternate in direction.
Although the function of the line current is to polarise the pallet it is not
required to produce any action neither of electromagnetic attraction nor of
neutralisation, the force of the springs moving the pallet away from the polo
of the electromagnet to which it adhered, and by which it is repelled upon
acquiring like polarity under the influence of the line current. Although thieso
actions are uniform in direction the function of the electro-magnet is not
necessarily to attract but only to retain the pallet the completion of the motion
of the pallet being effected mechanically by means capable of regulation according
to the results to be obtained.
In order to enable the receiving station to stop the sending station in case of
error without augmenting the current on the line, the interruption of the corre
spondence is effected by a current of double the intensity of the line current, sent
by the receiving station whilst the sending station is transmitting the current of
opposite sign which is effected by means of a commutator which only permits the
passage of the interrupting current under these conditions.