Improvements in the Art of and Apparatus for Telegraphing and Telephoning.
Year: 1890

page_text: Date of Application, 16th Sept., 1890-Accepted, 29th Nov., 1890
COMPLETE SPECIFICATION.
Improvements in the Art of and Apparatus for Telegraphing and
Telephoning.
I, S. LLOYD WIEGAND of 146 South Sixth Street, Philadelphia State of Pennsyl-
vania United States of America, Mechanical Engineer and Draughtsman 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 telegraphy and telephony, and has for its object the trans-
mission of articulate speech, and other sounds, or signals, by interruptions in the
tension of a connected electric circuit through longer distances than is practical with
electro-magnetic telephones, and is operated by sound addressed to a diaphragm or
other vibrating surface.
Heretofore the method of operating has been by forcing one electrode, usually of
carbon, to impinge upon the other electrode, and so vary the extent of contact and
conductivity of the circuit at that point, and sometimes by the reaction a severance of
the circuit is produced between the electrodes by which the electric tension in the
circuit is so affected as to control either an electro-magnet or a permanent magnet, so
as to vary its attractive force, and by such variation of attractive force, variably attract
and vibrate an elastic diaphragm, producing sounds similar to those addressed to the
transmitting diaphragm.
In this invention on the contrary, the electrode connected to the diaphragmn is placed
beyond the other electrode and instead of impinging upon the other electrode when
sound is addressed to the transmitting diaphragm, it is retracted from the other
electrode and immediately opens the electric circuit, which again automatically closes
and is again broken at each vibration and the extent of surfaces of the electrodes in
contact is varied at each closure by the variation of the impact.
This electric current instead of controlling the attractive force of a magnet, having
an armature forming a diaphragm, and operated by the attractive force of the magnet
at the receiving end of the line, controls a magnetizable core or har of metal, which
core with broad surfaces exposed to the atmosphere, expands and contracts differently
in its parts as it is magnetized and demagnetized, and by its local expansion and con-
traction and consequent changes of form, produces in the surrounding air sound waves
similar to those addressed to the transmitting diaphragm.
When very long lines or distances are to be used, a relay is introduced, consisting
of an expansible and contractible magnetizable core, which is controlled by the electrical
tension through a secondary circuit operated by induction from the electrical tension
of the primary circuit. in which the transmitting electrodes are located, and controls
and operates the second line so as to reach and operate through additional distance
and such second line by its own direct current, or preferably by an induced current
controlled thereby, operates an expansible and contractible core and a diaphragm formed
therewith or connected thereto, to reproduce sounds similar to those addressed to the
transmitting diaphragm.
An apparatus for practising this method is shown in the accompanying drawing, in
which,
Fig. 1 shows, at the left side, the transmitting instrument in section, at the
centre the relay instrument, and at the right, the receiving instrument in section.
Fig. 2 shows a modification of the transmitting instrument in section.
Fig. 3, a modification of the relay instrument.
Fig. 4, a modification of the receiving instrument.
Fig. 5, an elevation of the relay portion of the apparatus, with the connections and
adjuncts for "calling" it, or bringing it into, or suspending it, from operation.
Figs. 6 and 7, the expansible cores in modified forms, and
Fig. 8. another modified form of the receiver in section,

page_text: represents the sound receiving funnel, leading into the sound collecting cavity 2.
3 represents the transmitting diphragm, secured to the rim of the collecting
cavity 2. 4 is a stem or rod attached to the diaphragm 3 and projecting rearwardly
therefrom.
Attached to the stem 4 is an electrode 5, having its conducting point or surface,
towards the diaphragm 3.
In the telephone shown in Fig. 1, there is but one such electrode 5 connected to
the stem 2. In Fig. 2, there are several so connected. For greater compactness of
the transmitting instrument, the electrode 5, as shown in Fig. 2, is connected by means
of a lever 6 to the stem 4 and diaphragm 3, instead of directly to the stem 4.
Between the diaphragm 3, but without contact therewith and the electrode 5, thereto
attached, as shown in Fig. 1, is placed another insulated electrode 7 of carbon (or
other substance, having sufficient resistance to electrical conductivity), resting by
gravitation on an inclined plane or trough 40 against the electrode 5, so as to be in
contact therewith when the instrument is at rest. The electrodes 5 and 7 are
respectively connected electrically with the wires 8 and 9, through helices of the
primary circuit 11 of the induction coil 10, and in circuit with the battery 13, or an
equivalent means of producing or exciting electrical tension.
14 represents a core of magnetizable metal expansible lengthwise under the influence
of electric action or tension, or action in the circuit embracing the surrounding
helix 15.
The current through the helix 15 is transmitted through the line wires 16, connected
with the helices of the secondary circuit 12 of the induction coil 10.
The ends of the core 14 are connected by bars 17 to an electrode 18 of the secondary
or outgoing line of the relay, and the other end of the core 14 to the second
electrode 19 of such line is so placed as to rest against the electrode 18 so that when
the electric circuit passes through, the helix 15 is closed, the core lengthens and
moves the electrode 18 away from the electrode 19, opening the circuit in the
secondary line. The electrodes 18 and 19 are insulated electrically and one of them
is so supported or suspended that immediately after opening, they again close by
gravitation with a force proportionate to the distance which the electrodes have been
separated, the electrodes 19 being in the form of a sphere resting in an inclined
trough 20 of conducting material, having the lower end toward the electrode 18.
The electrodes 18 and 19 are in the same circuit with the battery 21 and the helices
surrounding the magnetic core forming the primary circuit of the induction coil 22
and the wires 23 and 24 of the secondary helix lead to the receiver 25, as shown in
Fig. 5. The secondary coil as shown in Fig. 5 has also other connections hereinafter
described for bringing into play intermittently an auxiliary battery.
For the purpose of describing the action, in telephony, or transmission of articulate
speech, of this invention, the connection of the wires 23 and 24 with the receiver 25
and the construction of such receiver is first described and explained.
The receiver 25 consists of an expansible magnetic core 26 surrounded by a helix 27,
in a circuit with the wires 23 and 24. Attached to one end of the core 26 is a plate 28,
which move with that end of the core. The opposite edges of this plate are attached
to a band 42 of magnetized or magnetizible material (preferably the former). The
opposite end of said core being permanently fixed to one side or end of a chamber
or receiver case and to the centre of the band 42 and motion from the free end resulting
from expansion and contraction of the core and changes in form which occur with
each magnetization and demagnetization or changes of magnetization in which the
plate 28 participates, vibrates the air in the chamber 29, surrounding said plate, which
vibrations communicate motion to the surrounding air through an aperture 30, into a
bell mouth 31, from which audible articulate sounds are emitted corresponding with
those addressed to the diaphragm 3.
In the form shown in Fig. 8, the central core 26 is made of curved plates united to
each other alternately at the ends and centres, one end of the case being secured to
the diaphragm 28 and the other end to the centre of the band 42, this form of core
being very compact and sensitive, the principles of its operation being the changes of

page_text: shape which it undergoes and imparts to the connected parts in consequence of
changes in its magnetic condition resulting from intermission of current and electrica
impulse.
When but short lines are required, the relay may be dispensed with and the wires 16
may lead directly to the helix 27 surrounding the expansible magnetic core 26 but
the length through which such transmission is satisfactory is much shorter than can be
attained by using the described relay system. If desired, several relays may be used,
one operating the next.
For the purpose of economizing in the wear of the battery material, an arrange-
ment of an electro-magnet with a device for connecting and disconnecting the auxiliary
battery may be employed as shown in Fig. 5. In this case when the electric tension
is made on the incoming line wires 32 and 33, these wires leading to the helices
around the electro-magnet 34, cause it to attract the armature 35, and severs the
connection from the secondary wire 23 and connects the circuit through the battery
wires 36 and line wire 38 from the battery 37, thus leaving out of circuit the secondary
helix of the induction coil 22, and establishing electrical connection with the main
line 24 and 38 leading to the next relay, or the receiving instrument 25 as the case
may be, and including in such circuit the battery 37, this circuit being opened and
closed by electrodes 18 and 19, as operated by the expansible core 14, as magnetized
and demagnetized by electric tension in the helix 15, through the wires 32, helices 34,
wires 39 and wire 33, from the secondary circuit of the induction coil at the trans-
mitting end of the line.
When very long distances are to be reached, relays of like construction and
operation controlled by a preceding relay instead of the transmitter are to be used.
The expansible cores can be made of single rods or tubes of iron or steel, or they may
be made of lamina of such metals, or they may be made prismatic as shown in Figs. 6
and 7 with notches or transverse clefts 41 therein, which construction enables a more
compact apparatus to operate with sufficient motion from a similar core and helix.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. The described method of transmitting articulate speech by retracting one
electrode from another in an electric circuit, and automatically thereafter alternately
closing and opening such circuit constantly during the transmission of speech in con-
junction with said circuit, and a helix either directly electrically connected or by
induction connected with said first circuit, and with helices surrounding an expansible
magnetic core having a connected plate or diaphragm, arranged to vibrate and impart
vibratory motion to the contiguous air for the purpose of producing articulate speech,
similar to that actuating the first pair of electrodes.
2. The method of extending the capacity of telephones to long distance, by
introducing an expansible magnetizable core subjected to the influence of the electric
circuit and controlled in tension by the electrodes connected to the transmitting
diaphragm, and by such expansive action producing motion controlling a second pair
of electrodes inserted in an electric circuit extending a further distance and arranged
to operate expansible magnetizable cores, and a connected diaphragm or piston, thereby
imparting vibrations similar to those of articulate speech to the adjacent air, substan-
tially as set forth.
3. In an apparatus for transmitting articulate speech telephonically, the combination of
a transmitting diaphragm with a mechanically connected electrode arranged to retract
said electrode from another in the same circuit, and also in circuit with a battery, and
the primary helix of an induction coil, the secondary helix of which is electrically
connected with a telephonic receiving instrument, substantially as set forth.
4. In a telephonic apparatus for converting a series of electrical impulses into sound
vibrations of articulate speech, the combination of an expansible core having an attached
diaphragm, with a surrounding insulated electrical helix whereby the core is expanded

page_text: and contracted as it is magnetized and demagnetized, and vibrates the air in contiguity
with the diaphragm, substantially as set forth.
5. In an apparatus for transmitting articulate speech and other sounds telephonically,
the combination of an expansible magnetizable core with a surrounding insulated
helix, the electric tension of which is controlled in electrical connection by a similar
instrument, with à pair of electrodes operated by the contraction and expansion of
another expansible magnetizable core in a second electric circuit and provided
with a separate battery or generator to reach through additional distances, substan-
tially as set forth.
6. The combination of an expansible magnetizable core with connected electrodes for
opening and closing and thereby changing the tension of a second electric circuit by
changing or interrupting the tension of a first electric circuit containing a helix
surrounding the magnetizable core, substantially as set forth.
7. The combination in a telephonic receiver of an expansible and contractable
magnetizable core having a connected piston or diaphragm adapted to vibrate the air
contiguous thereto, with a surrounding insulated electric helix adapted to receive
electrical impulses or changes of tension, and intermittently expand said core and
vibrate the diaphragm, substantially as set forth.
8. In an electrical apparatus, the combination with two electrodes, one arranged to
be actuated by gravity, of an expansible, magnetizable core, a helix encircling the
core and devices connecting the core with one of the electrodes, the parts
being so arranged that on the expansion of the core by the action of the current
flowing around it, contact of the electrodes will be diminished and subsequently
increased by the gravitation of the free electrode, substantially as set forth.
9. In an electrical apparatus, the combination with two electrodes, of an expansible
magnetizable core, a helix encircling the core and devices connecting the core with
one of the electrodes, the parts being arranged so that on the expansion of the core by
the action of the current flowing around it, contact of the electrodes will be diminished
and will be again increased by a force independent of that exerted by the core, sub-
stantially as set forth.
10. In a telephone transmitter, the combination with a diaphragm having an
electrode permanently connected so as to vibrate therewith, of a loosely mounted
electrode resting normally against the first electrode and arranged to be propelled by
vibrations of the diaphragm and its connected electrode toward the speaker and make
variable contact during ensuing reaction, substantially as set forth.
11. In a telephone transmitter, the combination with a diaphragm and an electrode
connected therewith so as to vibrate with the diaphragm, of an electrode loosely
mounted on a supporting inclined guide, said electrode being constructed and arranged
to diminish the contact by the movement of the diaphragm in a direction away from
the speaker, substantially as set forth.
12. In a telephone transmitter, the combination with a diaphragm and an electrode
connected therewith so as to vibrate with the diaphragm of a spherical electrode loosely
mounted and located between the diaphragm and the electrode connected therewith,
substantially as set forth.
13. In a telephone, the combination with a diaphragm and an induction coil, of two
electrodes, one connected with the diaphragm and the other loosely mounted and acted
upon by gravity, said electrode being inclined in the primary circuit of the induction
coil and arranged to be diminished in contact by the direct action of the diaphragm
and increased in contact after the reaction of the diaphragm, substantially as set
forth.
1. In an apparatus for transmitting sounds and signals, the combination with a
diaphragm and a helix located in proximity thereto, of an expansible core attached at one
end to the diaphragm, said core being composed of a series of plates arranged in pairs,
the ends of each pair of plates being secured together and the several pairs of plates
being connected together at their centres, substantially as set forth.
15. In an apparatus for transmitting sounds and signals, the combination with a

page_text: diaphragm of a helix located in proximity thereto an expansible core in said helix
connected at one end to the diaphragm, and a band of magnetizable material
connected at its ends to the diaphragm at diametrically opposite points, substantially
as set forth.
Dated this Fifteenth day of September 1890
CRUIKSHANK & FAIRWEATHER,
62, St. Vincent Street, Glasgow, Agents.