IMPROVEMENTS IN APPARATUS FOR PROTECTING TELEGRAPHIC INSTRUMENTS FROM INJURY FROM ATMOSPHERIC OR STATIC ELECTRICITY
Year: 1865

page_text: PROVISIONAL SPECIFICATION left by Auguste Bertsch at the Office
of the Commissioners of Patents, with his Petition, on the 14th March
1865.
I, AUGUSTE BERTSCH, Engineer, of Rue Fontaine St. George, 27, Paris,
in the Empire of France, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN APPARATUS FOR PROTECTING TELEGRAPHIC INSTRUMENTS
FROM INJURY FROM ATMOSPHERIC OR STATIC ELECTRICITY," to be as follows:-
This Invention has for its object improvements in apparatus for
protecting telegraphic instruments from injury from atmospheric or static
electricity.
Apparatus is now commonly used in which a fine wire is employed as the
conducting wire between the line wire and the telegraph instruments, in order
that if there be any discharge of static electricity through this wire the wire
may be burnt and the instruments remain uninjured. It is however important
that this class of apparatus should be so constructed as to work continuously
and independently of the will of the operatives. I therefore construct appara-
tus of this description in such manner as to remain permanently in the circuit,
and to operate automatically in such manner that when the fine wire which
connects the line wire with the instrument is burnt the wire is immediately
replaced by another fine wire brought into circuit by a movement of the
apparatus produced by a spring or other maintaining power. The apparatus,
as I prefer to construct it, is composed of a cylinder terminated at the ends

page_text: by discs; one disc is connected with the earth and the other with the telegraph
instruments. Around the first disc are placed a number of spring hooks insu-
lated one from the other and also from the earth. The opposite disc, which
is in connection with the instruments, is also provided with an equal number
of hooks, and is connected to the cylinder in such manner as to be insulated
from it for dynamic electricity. Fine wires are stretched from end to end of
the cylinder between the hooks on the disc. The cylinder is furnished with a
belical spring, which constantly tends to rotate the cylinder. The bobbin is
supported between two standards by a central axis; the axle at one end is
connected with the earth, and the other is connected with the telegraph instru-
ments by clips. Near the opposite disc is another clip, in which is held the
extremity of the line wire, and which carries a contact piece, against which
the head of one of the spring hooks firmly rests. On the opposite side of the
disc is a third clip communicating with the earth wire, and which also carries
a contact piece. The disc carries on its edge a plate of copper, which,
when the last of the fine wires has been burnt, rests on this contact piece,
and instantaneously establishes the communication between the line and the
earth. The cylinder is formed of a metallic tube carrying points which are
retained at a very short distance from the fine wires. Atmospheric electricity
has therefore always an easy path for regaining its equilibrium with the earth,
and it will thus be seen the apparatus is constantly in action as a discharger.
When one of the threads is burnt the hook which establishes the contact between
the line wire and the instruments is withdrawn by its spring into the disc, the
cylinder is then caused rapidly to turn by the spiral spring, which brings
the next hook up to the contact piece, which thus forms a stop to prevent the
cylinder from turning further. The communication is thus re-established by
the new fine wire placed in the circuit. This change is effected in the sixtieth
of a second, that is to say, in so short a time as not to interrupt the working
of the telegraph. When the last of the fine threads is destroyed, the
communication between the line wire and the earth is instantaneously
made direct by a projection from the disc, which takes the place of the last
book.