IMPROVEMENTS IN SPEAKING TELEPHONES.
Year: 1878

page_text: LETTERS PATENT to Joshua Franklin Bailey, of New York City, in the
United States of America, at present residing at Morley's Hotel, Charing
Cross, in the County of Middlesex, for the Invention of "IMPROVEMENTS IN
SPEAKING TELEPHONES.' A communication from abroad by George May.
Phelps, of New York City, in the United States of America.
"
Sealed the 20th December 1878, and dated the 22nd October 1878.
PROVISIONAL SPECIFICATION left by the said Joshua Franklin Bailey at
the Office of the Commissioners of Patents on the 22nd October 1878.
JOSHUA FRANKLIN BAILEY, of New York City, in the United States of
America, at present residing at Morley's Hotel, Charing Cross, in the County
of Middlesex. "IMPROVEMENTS IN SPEAKING TELEPHONES." [A communication
from abroad by George May Phelps, of New York City, in the United States of
America.]
This Invention has for its object improvements in speaking telephones.
In the construction of a speaking telephone six or other convenient number of
permanent magnets of curved form are attached by their similar poles to an iron
socket, into which a core of soft iron is fitted. The core is surrounded, at the end
which projects from the socket, with a bobbin of silk-covered wire. Facing the
core and the bobbin a thin iron diaphragm or disc is held, and springs in magnetic
contact with the outer ends of the permanent magnets bear against the edges of the
iron disc, and so connect it with the magnets that it becomes magnetised from the
circumference to the centre, whilst at the same time the pressure of the springs upon
the edges of the disc being of a light and yielding nature does not interfere with its
vibration. The disc is confined in a chamber, which, as is usual, is provided with a
mouth-piece. By preference the disc is held around its circumference between rings
of paper or soft material, and springs are applied to prevent the disc being too
rigidly held.
:

page_text: April 1879
JOSHUA-FRANKLIN BAILEY, of New York City, in the United States of
-America, at present residing at Morley's Hotel, Charing Cross, in the County
of Middlesex. "IMPROVEMENTS-IN SPEAKING TELEPHONES." A communication
from abroad by George May Phelps, of New York City, in the United States
of America.
This Invention has for its object improvements in speaking telephones.
In the construction of a speaking telephone six or other convenient number of
permanent magnets of curved form are attached by their similar poles to an iron-
socket, into which a core of soft iron is fitted. The core is surrounded at the end
which projects from the socket with a bobbin of silk-covered wire. Facing the core
and the bobbin a thin iron diaphragm or disc is held, and springs in magnetic
contact with the outer ends of the permanent magnets bear against the edges of the
iron disc and so connect it with the magnets that it becomes magnetised from the
circumference to the centre, whilst at the same time the pressure of the springs
upon the edges of the disc being of a light and yielding nature does not interfere
with its vibration. The disc is confined in a chamber which, as is usual, is pro-
vided with a mouth-piece.
By preference the disc is held around its circumference between rings of paper or
soft material, and springs are applied to prevent the disc being too rigidly held,
In order that the said Invention may be more fully understood and readily
carried into effect, I will proceed to describe the Drawings hereunto annexed.
DESCRIPTION OF THE DRAWINGS.
Figure 1 is a section of a speaking telephone constructed according to this
Invention, and Figure 2 is a plan of the same with some of the parts removed.
A, A, are curved permanent magnets; they are all fastened by screws to the iron
socket B, care being taken to obtain good and close contact; C is a soft-iron core
fitted nicely into the socket; it supports at its outer end the bobbin of silk-covered
wire D, such as it is usual to employ in telephones. The core may with advantage
have radial notches cut in it, as the Drawing indicates. The socket B has a flange B¹,
and the block E of ebonite, wood, or other suitable material is fixed to it by screws;
Fis a cap, attached also by screws to the block E; the mouth-piece F¹ is formed in
connection with this cap. The block E and cap F enclose between them a cavity
in which is the thin iron disc G. It is pressed up to the cap around its edges by
the vulcanite ring H. The ring H is let into an annular groove in the block E, and
has coiled springs H¹ beneath it. Rings of soft paper G are, interposed between
the-disc-and-the-cap, and also between the disc and the ring H. The outer ends
of the magnets A are fixed to the block E by screws, which serve also to fix the
blade springs I in their places. The springs I bear upon the edges of the disc G, and
so (the screws and springs being of iron) the disc is placed in magnetic connection
with the outer poles of the magnets.
The disc thus is very efficiently magnetised from the circumference, whilst the
pressure of the springs against the disc being light its vibrations are not interfered
with. For the purpose of adjusting the distance between the core C and the disc G
a spring K is arranged beneath a collar upon the core, and a screw L is fitted into
a hole tapped in the end of the core. The screw passes through a washer abutting
upon the end of the socket B, and thus when the screw is turned the core Cis
moved in the socket to or from the disc 'G. M, M, M; are little turn buttons.
which serve to hold the disc G in its place until the cap F has been put on and
secured. N, N, are the conductors by which the telephone is coupled in circuit with
another telephone at a distance,

page_text: Having thus described the nature of the said Invention, and the manner of per-
forming the same, I would have it understood that I claim,-
First. The construction of a speaking telephoue with six or other number of
permanent magnets, having similar poles magnetically connected with the core of
the telephone bobbin, whilst the other poles of the magnets are magnetically con-
nected with the disc or diaphragm around its circumference.
Second. The construction of a speaking telephone with springs, making magnetic
contact between the permanent magnet and the edge of the disc or diaphragm.
Third. The construction of a speaking telephone with six or other number of
permanent magnets, having similar poles magnetically connected with a socket, into
which the core of the telephone bobbin is inserted.
Fourth. The construction of speaking telephones, substantially as described, and
represented in the annexed Drawings.
In witness whereof, I, the said Joshua Franklin Bailey, have hereunto set
my hand and seal, this Fifth day of March, in the year of our Lord One
thousand eight hundred and seventy-nine.
JOSHUA F. BAILEY. (LS.)