IMPROVEMENTS IN TELEPHONES
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by the said José Dottin Husbands at
the Office of the Commissioners of Patents on the 10th March 1882.
JOSÉ DOTTIN HUSBANDS, of Queen Victoria Street, in the City of London,
"IMPROVEMENTS IN TELEPHONES
"
My Invention relates to telephones and is designed to provide for the con-
struction of instruments which shall be as efficient as, and much simpler and
cheaper of construction than, any of the telephones now in use.
According to my invention I utilize carbon or other suitable conducting
substances in a granulated, crushed, or pulverized condition as a medium for
transmitting the sonorous vibrations from the instrument to an electric current in
the circuit in which the said instrument is included, and the said Invention.
consists in the combination with suitable chambers or cavities, without a
diaphragm, of a tension regulator consisting of carbon or similar material in the
above condition so placed between the electrodes as to microphonically regulate
the strength of the current. I am aware that carbon in a pulverized condition
has already been adapted to telephonic purposes in instruments provided with a
diaphragm or disc, but as will be seen from the following description, the
construction of my instruments differs very materially from that of such former
instruments.
According to one part of my invention I construct an instrument, as follows,
that is to say, I take two cylinders or short tubes or funnels of brass or other
suitable material of such different diameters that when one is inserted centrally
within the other there will be between the two electrodes and all around the same
an annular space of about 1/16th of an inch, more or less. These two cylinders or
electrodes are fixed in a block of vulcanite, wood, or other suitable non-conducting
material in which are fixed the terminals for the connection of the telephonic
circuit wires.

page_text: The granulated or pulverized carbon or other material is placed in the said
aunular space between the two cylinders or electrodes and above or outside of the
material the said space is partially packed with cloth, india-rubber, or other flexible
non-conducting material, to prevent the displacement of the granulated carbon or
other material used as the tension-regulator.
I may modify the construction of this instrument by insulating the two
electrodes one from the other and leaving both ends open. Or I may employ a
single tube which will form one electrode, a wire or piece of metal inside the tube
forming the other electrode
I further modify the construction of my instruments as follows, that is to say, I
take a block of wood, vulcanite, ebonite, or other suitable non-conducting material
and form therein a cavity, space, or chamber in which I place the granulated or
pulverized carbon or other regulating medium; I fix in the said block the
terminals to which the wires of the telephonic circuit are connected in the usual
manner and I connect these terminals with the cavity containing the granulated
carbon by suitable wires or other conductors.
The instruments constructed as above described are made of convenient size to
be manipulated in the ordinary manner and may be provided with mouth-pieces
and other adjuncts as desired.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said José Dottin Husbands in the Great Seal Patent Office on the
9th September 1882.
JOSÉ DOTTIN HUSBANDS, of Queen Victoria Street, in the City of London.
"IMPROVEMENTS IN TELEPHONES."
My Invention relates to telephones, and is designed to provide for the con-
struction of transmitting instruments which shall be highly efficient, and simpler
and cheaper of construction than other telephonic instruments now in use.
My improved instruments are of that class whose principle of action is the
variation of the resistance in a closed circuit by, and in sympathy with, the
air-vibrations due to the sound-waves produced by the voice, or otherwise, within
the mouth-piece; the variations or changes in the resistance are due to variations
of pressure by some part of the instrument on a loose contact introduced into the
circuit between two good conducting surfaces, and for this purpose a diaphragm,
dise, or plate is ordinarily provided, and so arranged as to concentrate the sound-
waves upon the said diaphragm or disc. But according to my invention I dispense
with the diaphragm, disc, or plate in such instruments and so construct the same
that the mouth-piece itself, or an extension thereof, or a chamber connected
therewith, forms the medium upon which the sound-waves act to produce the
vibrations.

page_text: In practising the said invention I use a tubular mouth-piece (in some instances
placed within a suitable chamber or cavity) in combination with a tension-
regulator or loose contact consisting of carbon, such as granulated or powdered
coke or other suitable material so placed between the electrodes as to micro-
phonically regulate the strength of the current without a diaphragm as hereinafter
described and as represented in the accompanying drawing, which shews some of
the various forms of which the said invention is susceptible.
Figures 1, 2, and 3 are longitudinal sections of different forms of the said
instrument.
Figure 4 is a longitudinal section of a modification thereof.
Figure 5 is a section on the line x, x, Figure 4.
Figure 6 is a longitudinal section, and,
Figure 7 a section on the line y, y, Figure 6, illustrating a further modification
of my said invention.
According to one part of my invention I construct an instrument as shown in
Figure 1, that is to say, I take a block a of ebonite, wood, or other suitable
insulating or non-conducting material and I attach thereto the mouth-piece which
consists of two cylinders, short tubes or funnels b, c, of brass or other suitable
material which form the electrodes or conducting surfaces between which the
regulator is placed. These cylinders are of such different diameters that when one
is inserted centrally within the other there will be between the electrodes and all
around the same an annular space as shown; d, d, are the terminals for the
connection of the telephonic circuit wires.
The granulated or pulverized carbon or other material is placed, as shown at e,
in the said annular space between the two cylinders b, c, and the ends thereof are
packed with cloth, india-rubber, or other flexible non-conducting material, as shown
at f, to prevent the displacement of the granulated carbon or other material used
as the tension-regulator. I may modify this construction of my instrument by
insulating the two cylinders or electrodes from each other and leaving both ends
open.
In Figure 2 a is a block of wood or other suitable insulating material; this
block has a cavity or chamber formed therein and lined with metal or other good
Cucting material as shown at b. Within this lined cavity or chamber I insert
a tube c constructed of thin metal or of a thin substance coated with metal and so
formed and arranged that there is an annular space between it and the said
lining b, that is to, say between the two metal surfaces, which space is filled, or
partially filled, with powdered or granulated coke or other substance suitable to
serve as a regulating medium in a telephonic circuit. The wires or conductors of
the circuit are connected with the two metal surfaces b, c, so that the current has
to pass through the coke or other regulator and is therefore subject to vibrations
in sympathy with the vibrations caused by the impingement of the sound waves
upon the tube c.
In Figure 3 the block a is made in two pieces a¹, a³, secured by means of
screws a³, and the thin metal tube or mouth-pieee c which forms one electrode is
surrounded by a loosely fitting ring g of hard carbon or other regulating material,
and outside of the latter is placed a metal ring h which forms the other
electrode.
In Figures 4 and 5 I have shown another modification of my invention wherein
the vibrating tube or mouth-piece c is divided into two parts or halves c³ ³ placed
together, with insulating material between them. The action is similar to that
in the instruments above described, that is to say, each half or part forms one
electrode, the current entering by one part and passing through the granulated coke
or other material e to the other part of the said tube.
I may further modify my invention by making the vibrating tube or tubular
mouth-piece of ebonite or other suitable insulating material and coating or
covering two separate portions thereof with metal to form the two electrodes, the

page_text: said tube being placed in a cavity or chamber containing the coke or other regulating
material.
In Figures 6 and 7 is shown a further modification of my invention, in which the
mouth-piece is formed of a tube c of brass or other suitable material; this tube is
made with a slot c' in which is loosely fitted a small block or button e of carbon
or other regulating material. In this block or button is fixed a small piece of
metal e¹ which forms one of the electrodes, the tube c forming the other
electrode.
Having thus fully described my said invention and shown how the same may be
most conveniently and advantageously carried into practice, I wish it understood
that I am aware that carbon in various conditions or forms has been used prior to
the date of my invention in telephonic transmitting instruments provided with a
diaphragm or disc so arranged as to receive the impact of the air-waves in the
inouth-piece; I therefore do not claim any device or instrument in which a
diapbragm or disc is employed as the vibrating piece in a telephonic instrument,
nor do I claim generally or irrespectively of the novel features herein described,
the combination of a vibrating piece with carbon or other material for producing
variations in the resistance in a telephonic circuit, but I claim,
First. In a telephonic transmitting instrument, the employment of a mouth-
piece, or extension thereof, or chamber connected therewith, which also serves as
the vibrating contact piece or electrode whose action on the carbon or other
contact-regulating material causes the variations or changes in the resistance of the
circuit for the purpose specified.
Second. The telephonic transmitting instrument constructed with two metal
tubes or tubular surfaces between which the granulated or powdered carbon or
other regulating material is enclosed, substantially as described with reference to
Figure 1 or Figure 2 of the drawing.
Third. The modification of my invention wherein the vibrating tube or mouth-
piece is surrounded by a ring of hard carbon or other regulating material, outside
of which is placed a metal ring or annular electrode, substantially as described
with reference to Figure 3 of the drawing.
Fourth. The modification of my invention wherein the vibrating tube or
mouth-piece is divided into two parts placed together within a chamber or cavity,
but insulated from each other, substantially as described with reference to Figures 4
and 5 of the drawing.
Fifth. The modification of my invention substantially as described with reference
to Figures 6 and 7 of the drawing,
In witness whereof I the said José Dottin Husbands have hereunto set my
hand and seal this Eighth day of September in the year of our Lord One
thousand eight hundred and eighty two.
JOSE D. HUSBANDS. (LS.)