Year: 1886

page_text: I, WILLIAM ROBERT LAKE, of the firm of Haseltine, Lake & Co Patent Agents,
Southampton Buildings, in the County of Middlesex do hereby declare the nature
of this invention and in what manner the same is to be performed, to be parti
cularly described and ascertained in and by the following statement:―
This invention relates to the electrical transmission of sound.
If the generally accepted theory that the "Reis" system or method for the
electrical transmission of sound involves the alternate breaking and closing of the
line circuit by the transmitter be correct, then the known art of electrically
transmitting sound consists of two branches.-One branch is represented by the
"Reis
system; and the other branch is represented by the "Bell" system, in
which the transmitter never breaks the circuit on which it operates.
My invention relates to the "Reis" system, considering it as one in which the
transmitter habitually and alternately breaks and closes the circuit on which it
operates. I have found that it is not possible to transmit articulate sound in a
commercially practical manner over a line which is alternately broken and closed
by the transmitter, as in the Reis" system, although other sounds may be
successfully transmitted in that way.
The object of my invention is to so improve the "Reis" system that articulate
Bounds as well as other sounds can be successfully transmitted electrically. To
this end my invention consists in transmitting vocal articulations and other sounds
over a line or secondary circuit by electric currents induced by varying, as well as
breaking, the contact between two electrodes in the primary circuit associated with
the said secondary circuit.
In order that my invention may be clearly understood, I will proceed to describe
it as put into successful practice by the apparatus illustrated in the accompanying
drawing, which apparatus is the best for the purpose which I have so far devised,
although I have practised my invention with more or less success by means

page_text: of differently constructed apparatuses I have only illustrated the transmitting
apparatus, any suitable receiving apparatus may be used in connection therewith.
In the said drawing,
Figure 1 represents a transverse vertical section of an electrical telephonic
transmitter and shows a diaphragm electrode and a loosely supported and mov-
able electrode, a contact pressure regulating device, and an induction coil with
circuit connections arranged for operation to vary the strength of a battery current
and to break or interrupt the circuit when the diaphragm is vibrated by sound
impinging against it, in accordance with my invention.
Figure 2, is an elevation of the movable electrode and the platform or table
therefor, and
Figures 3 and 4 are elevations of the diaphragm and loose or ball electrodes,
showing different forms of outer or contact end of the diaphragm electrode.
A represents the transmitter case, and B the diaphragm having on its rear side
an electrod C, which is preferably of carbon and has its outer end c rounded,
tapered or otherwise suitably formed, and this electrode constitutes what I call the
diaphragm electrode, as it is secured to and moves with the diaphragm.
D is the remaining electrode, and for purposes of my invention I prefer to make
it of carbon in the form of a ball or sphere, to loosely support it upon an inclined
table or platform E, and to place the diaphragm electrode, the ball and the table
in the battery circuit, for reasons hereinafter stated.
The diaphragm is connected with one pole of the battery L, B, the other pole of
which is connected with one end of the primary coil of the inductorium L. The
table E is connected with the other end of said primary coil. The secondary coil
of the inductorium L is a portion of the line circuit..
The platform or table E is suitably hinged or pivotted at its forward end
(preferably in line with the centre of the ball D) to the sides of the transmitter
case, so as to place the horizontal and vertical axes of the ball as near as possible in
line, respectively, with the longitudinal centre of the diaphragm electrode and with
the vertical centre of the pivot or hinge connection of the table E as shown.
This position of the ball relatively to the inclination of the platform serves the
following functions :—
First to give an initial contact pressure between the electrodes, which pressure is
stable enough to maintain contact between the electrodes part of the time that the
diaphragm is vibrating under the influence of sound; but as the electrode D is a
ball and has a rattling motion on the table E, as the diaphragm, vibrates, such con-
tact pressure is not stable enough to prevent the ball, under the influence of the
resultant motion imparted to it by the diaphragm, from receding or parting form
the diaphragm electrode during, or at the end of, an impulse by the latter; and
Second to form a wedge shaped recess or chamber between the diaphragm
electrode and the table, which limits the receding or parting movement of the
ball, returns it to contact with the electrode, and prevents rebounding.
The described position of the ball electrode is. one that gives a light initial
contact between it and the diaphragm electrode, but as the table is in the battery
circuit an additional or a second initial contact pressure is obtained between the
ball and the table, hence the variations in the strength of the current are equal to
the sum of the variations of these contact pressures, or those between the diaphrag
electrode and the ball and between the latter and the table.
Any suitable screw or regulating device e may be employed to adjust the table
to vary its inclination for altering the degree of initial, contact pressure between
the electrodes.
The table may be wholly of metal or other suitable conductor, or it may consist
of a carbon block d having a groove for the reception of the ball and a metal or
other support d¹ for the carbon block or plate, as indicated in Figures 1 and 2,
I prefer this last described form, as it is evident that with the two carbon contacts
for the ball, the sum of its two initial contact pressures is greater than when one
of them is in contact with metal.

page_text: In this form of instrument there is, therefore, a ball electrode supported upon an
inclined table or electrode, and in contact with an electrode on the diaphragm ;
consequently when the diaphragm is vibrated by sounds spoken or impinging
against it the initial contact pressures of the ball are varied resulting in changes of
resistance of the primary circuit.
The ball partakes of the impelling movement or pressure of the diaphragm, and
the contact of the ball with the diaphragm is maintained by the inclination of the
table E, until the diaphragm slows up preparatory to its return swing, when the
ball moves backwardly more rapidly by reason of its acquired motion or force and
separates from the diaphragm electrode so as to break the primary circuit and
interrupt the battery current. But the continuous backward movement of the
ball is retarded by the inclination of the table E, and the ball soon returns to
contact with the diaphragm electrode re-establishing the primary circuit.
I have ocularly demonstrated that, with the size of ball shown, breaks occur
habitually in rapid succession when words are spoken into the transmitter in an
ordinary tone of voice, and that for whispering or very low tones of voice the same
result is obtained by a much smaller ball; for loud tones or for shouting a much
larger diameter of ball may be employed, but ordinarily the one shewn is the size
I use, as, by varying the inclination of the table from 2 deg. to 45 deg., the same
size of ball may be used to produce the result described.
By the successive changes of resistance and interruptions of the primary circuit,
electric currents are induced in the line or secondary circuit, which induced currents
so operate on the receiver that they reproduce the vocal articulations or other
sounds projected into the transmitter.
I have endeavoured to ascertain just what phases of a sound or articulation
cause breaks in the primary circuit; also what precise functions the induced
currents, resulting from the breaks and makes of the primary circuit, performed.
In these endeavours I have been unsuccessful. But I have ascertained that speech
transmitted according to my method is reproduced by a receiver with a distinctness
exceptional in that the syllables, and words are as clearly separated as in the
natural speech.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, as communicated to me by
my foreign correspondent, I declare that what I claim is
First. The method of transmitting articulate speech or other sounds telephonically
by induced currents over a secondary circuit, which method consists in causing the
air waves or sounds to vary the resistance as well as to open and close the primary
circuit associated with the secondary circuit, substantially as before set forth.
Dated this Sth day of January 1886.
HASELTINE, LAKE & Co.,
For the Applicant.