IMPROVED ARRANGEMENTS OR APPARATUS FOR TELEPHONIC AND MICROPHONIC PURPOSES
Year: 1879

page_text: LETTERS PATENT to James William Thomas Cadett, of Camberwell Grove,
in the County of Surrey, for the Invention of "IMPROVED ARRANGEMENTS OR
APPARATUS FOR TELEPHONIC AND MICROPHONIC PURPOSES."
Sealed the 14th October 1879, and dated the 18th April 1879.
PROVISIONAL SPECIFICATION left by the said James William Thomas
Cadett at the Office of the Commissioners of Patents on the 18th April 1879.
"
AND
JAMES WILLIAM THOMAS CADETT, of Camberwell Grove, in the County of
Surrey. 'IMPROVED ARRANGEMENTS OR APPARATUS FOR TELEPHONIC
MICROPHONIC PURPOSES."
My Invention consists of a transmitter to be used specially in connection with
telephonic arrangements, whereby an improved result is obtained when used with
telephonic or other receiver or receivers.
In carrying out my said Invention I adopt mainly the following arrange-
ments:-
To a board or boards, diaphragm or diaphragms, or surface or surfaces made of
any suitable material, I fix or place on one or both sides a set or sets of bearing
pieces, blocks, or rods, made of carbon or other suitable material. To these bearing
pieces, blocks, or rods, are fitted rods or pieces of carbon or other suitable con-
ducting material, forming a series or several series of conductors. Wires or other
conductors are arranged so as to allow of suitably connecting the various bearing
pieces, blocks, or rods, as may be required, into a scries or several series
coupled together, so as to have suitable resistance, so disposed that the arrange-
ments can be employed to the best effect with the battery or other power employed,
and the resistance of telephonic or other receiver or receivers, line wires, and so
forth.
The above arrangements are connected with regard to the line wire or wires in
the usual and well-known manner for electric telephony. In use, the sound to be
reproduced or conveyed is produced at a suitable distance from the board or boards,

page_text: diaphragm or diaphragms, or surface or surfaces, the result being that the vibra-
tions cause variations in the resistance of the conducting power of the instrument
made according to my Invention, whereby currents of electricity are made to pass
in waves or otherwise proportionally, and according to the sound produced, such
currents being used with regard to tho receiver, or receivers, or telephone in the
usual manner. The connecting and coupling arrangements before described permit
of the arrangements being made to suit the electric power employed, and also the
resistance of the line wire, telephone, or other receiver or receivers, and so forth.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said James William Thomas Cadett in the Great Seal Patent Office on the
18th October 1879.
JAMES WILLIAM THOMAS CADETT, of Camberwell Grove, in the County of
Surrey. "IMPROVED ARRANGEMENTS OR APPARATUS FOR TELEPHONIC AND
MICROPHONIC PURPOSES."
My Invention consists of a transmitter to be used specially in connection with
telephonic arrangements, whereby an improved result is obtained when used with
telephonic or other receiver or receivers.
In carrying out my said Invention I adopt substantially the following arrange-
ments:-
To a board or boards, diaphragm or diaphragms, or surface or surfaces, made of
any suitable material, I fix or place on one or both sides a set or sets of bearing
pieces, blocks, or rods, made of carbon or other suitable material. To these bearing
pieces, blocks, or rods, are fitted rods, pencils, or pieces of carbon or other suitable con-
ducting material, forming a series or several series of conductors. Wires or other
conductors are arranged so as to allow of suitably connecting the various bearing
pieces, blocks, or rods as may be required into a series or several series, coupled
together so as to have suitable resistance, and so disposed that the arrangements
can be employed to the best effect with the battery or other power employed, and
to suit the resistance of telephonic or other receiver or receivers, line wires, and so
forth.
The above arrangements are connected with regard to the line wire or wires in
the usual and well known manner for electric telephony. In use, the sound to be
reproduced or conveyed is produced at a suitable distance from the board or boards,
diaphragm or diaphragms, surface or surfaces, the result being that the vibrations
cause variations in the resistance of the conducting power of the instrument made
according to my Invention, whereby currents of electricity are made to pass in
waves or otherwise, proportionally and according to the sound produced, such
currents being used with regard to the receiver, or receivers, or telephone in the
usual manner. The connecting and coupling arrangements before described permit
of arrangements being made to suit the electric power employed, and also the
resistance of the line wire, telephone, or other receiver or receivers, and so forth.
Having thus far described the nature of my said Invention, and incidentally
intimated in what manner the same is to be performed, I will now proceed (aided
by the accompanying Drawings) to further and particularly describe and ascertain
in what manner the same is to be performed or carried out in practice, that is to
say:
DESCRIPTION OF THE DRAWINGS.
Ti hann a form of the
Amments
annemature made according to mo

page_text: preferably placed so as to keep the pencils or pieces from touching the board or
surface B. It must be understood that any desired number of blocks or bearing
pieces such as p, and pencils or pieces such as ', may be used, the number being
practically determined according to the power of electricity and the resistance of
the circuit or circuits employed. In Fig. 1, five series of six pencils or pieces ŕ in
each series are shown, the pencils or pieces being supported between and by the
blocks or bearing pieces p. Suitable wires or other conductors are fixed, as may
be required to the blocks p, so as to enable suitable connections to be made between
the blocks or bearing pieces p, so that any desired combination or coupling may be
made to suit the resistance of circuit or circuits and power of electricity employed;
for instance, in cases requiring a high resistance, supposing the block or bearing
piece marked t to be made a terminal of the apparatus, the current of electricity
used would pass through series 1, and then pass into series 2 by a connection or
conductor (shown by the dotted line), and so on through all the series; the last
blocks or bearing pieces p, marked in series being in this case the other
terminals of the apparatus or transmitter. It is of course plain that in coupling
different series together, any one of the series may be taken as the first, and any
other the second, and so on, and that either end of a series may be taken to join to
another series as may be required. The coupling shown in Fig. 1 is made regularly
merely for explanation, and does not necessarily alter the effect of the method of
coupling; as, for instance, if the resistance required necessitates that the current of
electricity employed should pass through all the series, one after another, it is
plain that any one series may be taken as first, any one of the remaining series as
second, and so on.
In Fig. 2 another arrangement is shown, and it will here be seen that the first
and last block p of each series are respectively connected together to form the
terminals t¹ and t of the instrument or apparatus as shown by the dotted lines.
The current of electricity would in this case divide itself between the series. If
desired in the case of Fig. 2 conductors may be fixed so as to connect the second
and third blocks p of each series respectively, as shown in Fig. 3. Fig. 4 shows
another combination of conductors between the blocks or bearing pieces p where
the first and last blocks of each series are all connected to conductors to form one
terminal t', and the centre blocks or bearing pieces of each series are connected by
conductors to form the other terminal t. In this case the current would divide
between the first and last blocks p of each series for one terminal, and divide
between the centre blocks or bearing pieces p and both sides of the said centre
blocks for the other terminal. It will be seen that many other combinations
or coupling arrangements can be adopted in instruments or apparatus made according
to my Invention, the most suitable arrangement of coupling being practically
determined according to requirements. In using the apparatus made according to
my Invention as a transmitter for telephonic purposes the connections with regard
to the telephone receiver or other receivers, battery line, earth, etc., may be made in
a similar manner as is done with an ordinary microphone.
Figs. 5 and 6 show two methods of connection with line, battery, telephone, etc.,
and explain the nature of the connections to be made with regard to my Invention.
T, Fig. 5, is the transmitter or apparatus made according to my Invention, in which
it is presumed that the internal coupling mentioned in reference to Figs. 1, 2, 3,
and 4 has been practically determined, and that t¹, t, are the terminals. Ono
terminal (say t¹) is connected with one pole of a battery B', the other terminal {* is
connected with 2 which is one terminal of the primary wire of an induction coil I,
the other terminal p' of the said primary wire of the induction coil I is connected
to the other pole of the battery B'. A terminal of the secondary wire, say S, of
the induction coil I, is connected with the line wire L, and thence to a terminal of
the telephone or other suitable receiver or receivers R, the other terminal of the
telephone or other suitable receiver is connected to earth or return wire; the other
terminal of the secondary wire S³ is connected to earth or return wire.
In Fig. 6 the letters and Figures refer to the same parts as in Fig. 5.

page_text: One terminal t¹ of T is connected to one pole of the battery; the other pole of
the battery is put to earth. The other terminal of T is connected to line wire L
and thence to telephone or suitable receiver or receivers, and from such telephone
receiver or receivers to earth. In practice if it is desired to convey speech electrically
a person speaks at a reasonable distance from T; the sounds produced cause the
board or other surface B to vibrate; the vibrations are conveyed by p (Fig. 1) to
the pencils or rods (Fig. 1), thus causing contact pressure between rand p to vary
according to the vibrations. With variation of the said contact pressure comes
variation of electric resistance between r and p, and thus waves of electric force
pass through the instrument T. The action of the said electric wave is well known
with regard to the telephone or other receiver by electricians, and therefore does
not need further explanation.
It will be seen that the construction of the transmitter or apparatus made
according to my Invention may be considerably varied without departing from the
principle thereof; for instance, instead of the board B several such boards as B
could be used, each board having one or more of the pencils supported by blocks
such as p, and suitable conductors as may be required connecting the blocks 2 of
the several boards together.
In the case of Figs. 2, 3, and 4, where the respective blocks p of each series are
connected together by conductors, the said connected blocks could be replaced by one
long block reaching through all the series, and so on. Moreover, instead of the
pencils resting by their weight on p they could be pressed against p by suitable
springs, or they could be held by springs in any suitable manner. Further, it will
be seen that the blocks p and the pencils might be of various shapes, and also
that the indentations in p might be dispensed with so that the pencils might simply
rest on p; and also that instead of the pencil r resting between and on two blocks p,
such pencils might be made as pieces, each resting only on one block p with a wire
or other conductor connecting such piece to any other piece or block as the case
might be. It will thus be seen that great variety might be made with regard to
details of construction in the apparatus made according to my Invention, and the
said variety of construction would not create any departure from the principle of
my Invention.
Having now particularly described and ascertained the nature of the said
Invention, and in what manner the same is to be performed or carried out in
practice, I may state that I am aware that arrangements for using a number of
pieces of carbon or other similar conductors in microphones have been heretofore
known; but what I claim is the Invention of "Improved Arrangements or Apparatus
for Telephonic and Microphonic Purposes," substantially as bereinbefore set forth
and described, in which Invention the important point or feature is combining &
number of blocks, pencils, or pieces, and bearing pieces, and coupling the same,
substantially as and for the purposes described.
In witness whereof, I, the said James William Thomas Cadett, have hereunto
set my hand and seal, this Eighteenth day of October, in the year of our
Land One thous
J. W. T. CADETT. (L.S.)
Witness,
T. MORGAN,
Secretary,
Inventors' Patentright Association, Lª.,
21, Cockspur Street, Charing Cross, S.W.