Year: 1886

page_text: I, WILLIAM CHANCY LOCKWOOD, of 29 Nassau Street, New York, in the County
of New York, and State of New York, in the United States of America, Electrician,
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 certain improvements in telephones and telephonic
systems, and it has for its object to provide for passing a powerful current, which
will overcome great resistance through the main line of the telephonic 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.
To this end the invention consists in providing a local circuit having the battery
and transmitter in electrical circuit, with two spools or helices properly arranged;
and the line wires leading to the receivers in circuit with a spool or helix, located
between the two spools or helices, the cores of the three spools respectively being
separate, but arranged longitudinally in line with each other, as will be more fully
hereinafter explained.
The above mentioned objects I accomplish by any convenient arrangement of
coils which will effect the conditions before named, but to fully illustrate my
invention, reference is made to the accompanying drawings forming part of this
specification, in which,
Figure 1 represents a top view of the coils or helices of the local and main lines,
in their proper relative positions.
Figure 2 is a view of a transmitter forming part of the local circuit, and
Figure 3 is a diagram showing my invention arranged in connection with a
complete telephonic system.
A indicates the transmitter, which consists preferably of a casing of suitable
shape, having two or more vibrating plates constructed of glass or other suitable
material, and mounted between conductors B, which form a connection between
the two binding posts C, and the wires D, E, of the local circuit of the system.
The said wires connect with the coils of the spools F, G, and the battery H con-
stituting the local circuit. The coils or helices are wound around iron cores, in
such direction as to have the opposite poles opposite each other, that is to say,-

page_text: the north pole of one facing the south pole of the other whenever the coils are
subjected to the action of the current from the battery. The letter I indicates
the coil, or helix which forms part of the main line or circuit. The said coil or
helix is composed of insulated wire wound around a core of soft iron which is
located longitudinally, in length with the cores of the spools or helices F, G, but
disconnected from the same, and the terminals of the wire forming the spool or
helix I, connect with suitable binding posts from which proceed the line and ground
wires of the main circuit, in which the receiving instruments at each end of the
line are embraced.
The coils or helices F, G, with their cores, may be adjustably mounted and
controlled by set screws K, L, so that they may be adjusted longitudinally to
and from the poles of the coil or helix I in order to vary the strength of the
current over the main line, according to the resistance offered by the same.
The letter M indicates a relay which may be located in the main line. This
consists of a series of spools or helices, precisely like the spools or helices F, G, I.
The spool I is located directly in the line, and the spools F, G, in the local or
battery current of said relay.
As constructed, it will be observed that the cones of the primary and secondary
coils or helices are entirely independent of each other, so that the secondary coil
receives its current entirely from the magnetic induction in the field between
the cores of the two primary coils, between which the core of the secondary
coil is located, and will be controlled by the vibrations in the diaphragms and the
consequent variations in the local circuit caused thereby.
Any approved electrical transmitter may be employed in connection with my
improved system without departing from the spirit of my invention; the ordinary
induction coil, usually employed in such cases, however, being omitted and the
local circuit connected directly with the primary coils above mentioned.
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. A telephonic instrument composed of two spools or helices, adapted to be
placed in a local telephonic circuit, and an intermediate spool or helix adapted to
be placed in the main or line circuit; the spools having separate or independent
cores, substantially as and for the purposes specified.
2nd. In a telephonic system, the combination with the local circuit embracing
a suitable transmitter and battery, of the spools or helices having separate and
independent cores, adapted to establish a current by magnetic induction in the
main line leading to the reservoir, substantially as specified.
3rd. The combination with the local spools and their connections, of the inter-
mediate spool and its connections, the cores of the respective spools being indepen-
dent and separate from each other and located longitudinally in line with each
other, substantially as specified.
4th. In combination with the main line spool or helix, the local spools or helices
having independent cores, and adjustably mounted at each end of the main spool,
and the adjusting screws whereby the local spools may be adjusted to and from the
main spool, substantially as set forth.