Year: 1886

page_text: I, HENRY HARRIS LAKE, of the firm of Haseltine, Lake & Co, Patent Agents,
Southampton Buildings, in the County of Middlesex, do hereby declare the
nature of my invention and in what manner the same is to be performed, .to
be particularly described and' ascertained in and by the following statement:-
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This invention relates to telegraphy and comprises a system or combination of
instruments and electric circuits for sending and receiving, telegraphic, signals by
means of induced or secondary currents.
The improvements which constitute the invention are a novel arrangement of
circuits, whereby a great saving of battery power is effected, and the combination
therewith of a circuit closer and a circuit reverser by means of which the working.
of a line is greatly facilitated.
One of the methods of operating a telegraphic line heretofore practised, has been
to use an induction coil at each terminal, the primary coil of each induction.coil
being included in a local circuit with a battery, and the secondary coil in the main
line. To produce the signalling currents, the direction of the current in one of the
primaries was reversed by means of a key, and a corresponding current impulse
thereby induced in the secondary coil and main line. The manipulation of a circuit
reversing key, however, is attended with difficulty, and opposes an obstacle to
the practical working of such a system. One of the main objects of this invention
is to obviate this difficulty and this is done by using an ordinary make and break
key in conjunction with an electrically controlled reverser, by means of which the
operation of reversing the current through the induction coil is performed by a
battery and not directly by the hand of the operator.
In applying this combination, but one battery is used for operating the receiver,
the reverser and the induction coil, the circuit from such battery being divided into
three branches in the manner hereinafter set forth. .
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There are also used switches and other instruments as are necessary for the
successful operation of the system, the details. of the construction and mode of
operation of which will be more fully understood by reference to the accompanying
drawing.
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page_text: The figure is a diagram showing the improved arrangement of circuits and the
relations of the several instruments used in conjunction therewith.
A is the main or signalling line extending between two or more sections, B is
the primary of the induction coil at one of the stations or terminals and Ċ the
secondary of the same. The main circuit branches at the induction coil, one branch
including the secondary and going to ground at D; the other branch leading to a
switch key E, the contact plate of which is grounded at D'. In the main line is
.a polarized relay F.
The reverser which is used consists of an electro magnet G in face of the pole of
which is a spring actuated vibrating armature H. The free end of this armature
is provided with contact points a, a, situated between the contacts b, c carried
by two spring-actuated levers K L. Between other contacts d, e on these two.
levers K, L is a pair of stationary contacts f, g; and these parts are so related
that, when the armature H is moved slightly towards the magnet, the contacts c, a
and d, fare brought together and the others separated; or, when the movement is
in the opposite direction, the contacts b, a and g, e are brought together and the
others separated.
M is the battery, Its circuit is divided into three branches; one, formed by the
wires m, n, o, includes the magnet C and an ordinary circuit closing key O.-
Another formed, by wires m, p, n, includes the sounder or other form of receiver,
and is partly through the frame and armature lever of the polarized relay. The
third branch is formed by wires m, t, to the armature H of the magnet G, from
whence it extends through the primary of the induction coil by wire 8 and back to
the battery by the wire w, the switch key P and wire n.
At the other terminal or station are similar devices arranged in the same manner
as here shown.
The operation of the system is as follows.
In order to transmit signals by means of the key O, the switch key E is opened,
so that the line or main circuit is grounded through the secondary of the induction
coil. The switch key P on the other hand is closed so as to bring the contacts f g
into connection with the battery. The key O. is then operated to make and break
the circuit through the magnet C. On closing the branch including this magnet,
the armature H is attracted towards the magnet and a current sent through the
primary of the induction coil. This induces a current on the line which operates
the polarized relays at the sending as well as the receiving stations. On raising
the key O, the circuit through the magnet G is interrupted, a current impulse of
opposite direction to the first, sent through the primary of the induction coil by
the reaction of the armature H, and the relay armatures shifted to their original
position.
When not sending by key O, the operator closes the key E, so as to short circuit
the primary of the induction coil, and opens key P, current impulses coming on
the line operate the polarized relay and the receiving instrument in the usual way.
The invention is obviously not limited to any specific form of the several instru-
ments described, as any others that perform the same functions may be used.
Having now particularly described and ascertained the nature of the said inven-
tion 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 :-
First. In a telegraph system operating by induction, the combination with an
induction coil, of a circuit closing key and an electro magnetic reverser operated
by the key for reversing the circuit through the primary of the induction coil, as
herein set forth.
Second. In a telegraph system operating by induction, the combination with an
induction coil of an electro magnetic reverser and a circuit closing key arranged in
branches of the same circuit in the manner set forth.
Third. In a telegraph system operating by induction, the combination with
an induction coil of an electro magnetic circuit reverser, a circuit closing key, a

page_text: polarized relay and a receiving instrument, the primary of the induction coil, the
circuit reverser, key and receiver being included in branches of one circuit, as, and
for the purpose, set forth.
Fourth. In a telegraph system operating by induction, the combination with a
main line including a polarized relay, and branched whereby it is adapted to be
grounded either through or around the secondary of an induction coil, of a local
circuit divided into three branches, one branch including the electro magnet of
a circuit reverser, and a circuit closing key, another branch including the primary.
of the induction coil, and the circuit reversing devices, and the third branch the
receiving, instrument and the controlling or circuit closing portions of the relay,
all as set forth.