Improvements in Telephonic Apparatus.
Year: 1892

page_text: Date of Application, 1st Mar., 1892-Accepted, 2nd July, 1892
COMPLETE SPECIFICATION.
Improvements in Telephonic Apparatus.
I, WILLIAM CHANCY LOCKWOOD, of Everett Hotel, in the City, County,
and State of York, United States of America, Electrician, do hereby declare
the nature of this invention and in what manner the same is to be per-
formed to be particularly described and ascertained in and by the following
statement:-
This invention relates to certain improvements upon the invention for which
Letters Patent of the United States were granted to me on the 27th day of July
1886, No. 346,377 for Improvements in Telephones, and which had for its object to
provide for passing a powerful current, capable of overcoming a great resistance
through the main line of telephone system by the inductive magnetic action of the
cores of a series of spools embraced in a local or battery and transmitter circuit
upon the core of an independent spool embraced in the main or receiver circuit.
The present invention has the same object in view.
The above mentioned objects are attained by the means illustrated in the
accompanying drawing which represents a diagram showing my telephonic system
complete.
Referring to the drawings, the numeral indicates a transmitter of any suitable
description such as the Blake for instance, in which, however the induction coil
usually employed is omitted the contract bearings of said transmitter being
connected directly to the binding posts 2. The numeral 3 indicates a local circuit
conductor embracing a battery 4, and the spools 5 of an electro-magnet 6, the
electro-magnet being preferably of the horse-shoc form and so represented in the
present instance. The numeral 7 indicates a similar electro-magnet, located so
that its poles will be opposite the poles of the electro-magnet 6, nearly but not in
contact with said magnet. The numeral 8 indicates the spools of the magnet 7,
the terminals of the cords of which connect with the conductor of the local circuit
From the con-
at the points 9 and 10 by means of the conductor 11 and 12.
ductor 11 extends a conductor 13 which connects with the ground as shown.
numeral 14 indicates a magneto-telponic receiver of the usual description one
terminal of the coil of which connects with the local circuit conductor 3, preferably,
at the point of connection 10 of the conductor 12. The other terminal connect
with the main line conductor 15 leading to a distant station at which is located a
system of devices and circuits identical to that above described.
The
The spools are doubly wound with coils of different resistance, say for instance,
one coil may be of No. 28 wire and the other of 22. The respective coils are
wound parallel with each other, and equalize the current of the primary; for
instance, if ten cells of a battery are in the primary circuit with a fifty mile line,
and it is wished to connect the same instrument in a ten mile line, the battery
current will device through the double-wound spool and balance. The spools of
the magnet 7 are singly wound and are of greater resistance than the coils 5 of
the magnet 6, the coils of said magnet being of No. 36 wire for instance. The
relative resistances of the coils however will depend upon the length of the line
and various circumstances and will have to be varied as occasion requires.
The operation of my invention will be readily understood on connection with the
above description and is as follows.
The system at the different stations being connected as shown in the drawing,
and which for convenience are designated by the letters A and B, it will be assumed
for instance, that transmission is to be effected from A to B.
It will be observed that there is a constant electric current established and
maintained through the local circuit transmitter and coils 5.
ΓΙ

page_text: Upon speaking into the transmitter, the undulations caused in the current of
the local circuit cause the magnet-6 to act inductively upon the magnet 7,
establishing an induced current through the coils 8. The contact points of the
home-station transmitter, when the diaphragin isevibrated, offer a greater resistance
than the transmitter at the distant station, when the contacts are undisturbed
during the variations of the current. Hence the current from the home-station
is not short-circuited but naturally goes over the line, the secondary or induced
current being forced or-assisted over the-line by a portion of the primary-current-
which also goes to the line.
The course of the current of the local circuit is indicated by single headed
arrows; the course of the current of the main or line-circuit indicated, by double-
headed arrows.
It will be perceived that in my improved, system, the secondary circuit or
circuit carrying the induced current is arranged within the local current, and that
both circuits are grounded by. a common conductor...
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is, to be,performed, I declare that what
I claim is:.
1st. In a telephonic system, a local circuit embracing a transmitter, a battery and
an electro-magnet, in combination.with a circuit arranged.,within, said local circuit
and embracing an electro-magnet and conductors.connecting with said. local circuit
and the line and ground conductors, whereby the circuits are grounded, substantially.
as spécified.
2nd. In a telephonic system, a local circuit. embracing a transmitter, and an
electro-magnet, in combination with a secondary circuit embracing an electro-magnet
and a conductor connecting said local and secondary. circuit with the line conductor
and ground whereby a secondary or induced current is impelled or forced over the
line by the primary current, as specified.
. 3rd. In a telephone system, the combination of the horse-shoe magnets with
opposing poles, the coils of one being in a local circuit embracing
a battery and
transmitter and the coils of both being with the main line and ground, whereby an
enforced secondary current is driven over the main line, substantially as specified..
"Dated this 1st day of March 1892.
W. C. LOCKWOOD,.
By L. W., per F. B. 35