Improvements in Telephonio Apparatus.
Year: 1896

page_text: Date of Application, 4th Feb., 1896
Complete Specification Left, 4th Nov., 1596-Accepted, 24th Dec.. 1895
PROVISIONAL SPECIFICATION.
Improvements in Telephonio Apparatus.
We, EDWARD WYTHE SMITH of 66 College Street, Chelsea, London, in
the County of Middlesex Electrical Engineer and THE NEW PHONOPORE
TELEPHONE COMPANY-LD. of Faraday House, Charing Cross Road, London, W.C.
do hereby declare the nature of this invention to be as follows:-
Our invention relates to telephones constructed to work simultaneously with
other apparatus on the same line wires, in which telephones the call signal is
given by the operator at the calling station pressing a key which closes a battery
circuit through the primary of the induction coil and a vibrating reed, thus sending
vibratory or harmonic currents to line. At the station called these currents pass
through a telephone receiver and cause the diaphragm to vibrate emitting a sound.
In order to strengthen the received currents we arrange the key and lever switch
with contacts in such a manner that the primary of the induction coil is on a
closed circuit when the key is not depressed and the lever switch is down; this
diminishes the inductive effect of the induction coil and strengthens the signalling
current passing through the receiver at the station called.
For giving communication along two line wires in different directions we
construct an instrument consisting of two telephone receivers, one connected at
one terminal to each line wire, to render the call signal, and one microphone
transmitter and indication coil. We fit the instrument with a commutator to
connect the induction ceil to either line wire as required, and arrange the
commutator so that it simultaneously brings a phonopore coil or condenser into
the circuit of the telephone receiver connected to the other line wire.
Defed this 4th day of February 1896
E. WYTHE SMITH.
THE NEW PHONOPORE TELEPHONE CO., LD.,
CHARLES ISAAC, Secretary.
Improvements in Telephonic Apparatus.
We, EDWARD WYTHE SMITH of 66 College Street, Chelsea, London, in
the County of Middlesex, Electrical Engineer, and THE NEW PHONOPORE
TELEPHONE COMPANY, LIMITED, of 85 Queen Victoria Street, London, E.C.,
formerly of Faraday House, Charing Cross Road, London W.C. 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:
Our invention relates to an arrangement of telephonic apparatus such that the

page_text: telegraphic apparatus.
cace on the same line wire with other
The call signal is as usual given by the operator at the calling station pressing
a key which closes a battery circuit through the primary of an induction coil and
a vibratory reed, thus sending vibratory or harmonic currents to line. At the
station called these currents pass through a telephone receiver causing it to
sound.
According to our invention, in order to strengthen the received currents, we
arrange the key and lever switch with contacts in such a manner that when the
instrument is in condition to receive a call, the key not being depressed and the
lever switch being down, the primary of its induction coil is a closed circuit. This
by diminishing the inductive effect of the induction coil strengthens the signalling
current passing through the receiver.
Fig. 1. shows our invention applied to a telephone with a "phonopore" coil of
which p, p, indicates the primary winding, and s, sand, s the secondary
winding.
The primary circuit p, p,
and the hook lever H.
is closed through the key K, the contacs y and m
When the key K is pressed against the contact, the primary circuit is closed
through the vibrator V and contact A, the battery C Z, contact in and switch
lever H.
This induces currents in the secondary circuits, s,, which, through the
receiver Ra and one terminal L, is connected to line and, through the receiver R
and the other terminal E, is connected to earth or return line.
When the hook lever H is up, it makes contact with a closing the primary
circuit through the microphone transmitter M and the battery IZ.
Although two telephone receivers R and Ra are shewn, either of these may be
dispensed with.
Instead of a "phonopore" coil an ordinary induction coil may be used, a
condenser being interposed between the secondary and either or both of the
terminals E, L.
For giving communication along two line wires in different directions, we
construct an instrument consisting of two telephone receivers, one of which is
connected at one terminal to the one line wire and the other similarly connected
to the second line wire to render the call signals, one microphone transmitter and
one induction coil being employed with these.
We provide the instrument with a commutator to connect the induction coil to
either line wire through the corresponding receiver, as required, and we arrange
the commutator so that it simultaneously brings a "phonopore" coil or a
condenser into the circuit of the telephone receiver connected to the other
line wire.
In Fig. 2, Ra and R bare two receivers, each of which has its one terminal
connected respectively to the two lines La and L b, its other terminal can be
connected by means of the commutator J to either the coil A or the coil B.
Of these A is a "phonopore "coil with primary connected up similarly to that
described with reference to Fig. 1, and its secondary connected at one terminals
to earth at E through the receiver R; and B is a simple "phonopore " coil without
a primary, its terminal is connected to earth at E.
"
When the handle 4 of the commutator is in one position, the "phonopore
induction coil A is connected to the line La through the receiver Ra; com-
munication can then be made along the line wire La, while signalling currents
from the line wire Lb may pass through the receiver R b and the coil B.
In another position of the handle h the coil A is connected with line Lb through
the receiver Rb, the receiver R a being then connected to the coil B.
For the "phonopore" induction coil A may be substituted an ordinary induction
coil, a condenser being placed in either or both secondary branches, and a condenser
may be employed instead of the coil B.

page_text: Having now particularly described and ascertained the nature of our invention,
and in what manner the same is to be performed, we declare that what we
claim is :-
1. In telephonic apparatus arranged to work on the same line wires with other
telegraphic apparatus in combination with the contact key and the switch lever
contacts y and m, whereby the primary of the induction coil is short circuited when
the instrument is in condition to receive call.
2. In telephonic apparatus arranged to work on the same line wires with other
apparatus, the combination of the receivers with a commutator, whereby com-
munication in two directions can he effected substantially as described.
Dated this Third day of November 1896
E. WYTHE SMITH.
THE NEW PHONOPORE TELEPHONE CO., LD.,
CHARLES ISAAC, Secretary.
ARND. HALT,
M. MOCATTA,
}
Directors.