IMPROVEMENTS IN TELEPHONE RECEIVING APPARATUS
Year: 1882

page_text: LETTERS PATENT to Richard Theiler and Meinrad Theiler, both of 86, Canon-
bury Road Islington, in the county of Middlesex for an Invention of
IMPROVEMENTS IN TELEPHONE RECEIVING APPARATUS
PROVISIONAL SPECIFICATION left by the said Richard Theiler and Meinrad
Theiler at the Office of the Commissioners of Patents on the 23rd August
1882.
RICHARD THEILER and MEINRAD THEILER, both of 86, Canonbury Road,
Islington, county of Middlesex IMPROVEMENTS IN TELEPHONE RECEIVING
APPARATUS
This invention partly relates to an improvement in and connected with the
telephone receivers in respect of which Letters Patent were granted to us, dated
16th November 1881. According to the said former Letters Patent, the lateral
vibrations of an electro-magnet when under the influence of a vibratory current,
were communicated to a tympan or diaphragm.
Now according to the present invention, the said lateral vibrations are com-
municated to a stem, or knob of ivory wood, horn or any other suitable substance
of such a shape that it can be conveniently inserted into the aperture of the ear or
pressed against the ear.
In carrying out our invention, we do however not confine ourselves to making
use of the lateral vibrations only of an electro-magnet, as described in the said
former Letters Patent but may attach the said stem or knob to a tongue or bar of
soft iron fitted in such a manner that one end thereof can vibrate freely close to the
pole or poles of an electro magnet.
As a freely vibrating tongue or bar cannot however reproduce articulate speech,
we check or damp the vibrations by attaching the said stem or knob to the free
end of the tongue or bar and inserting the former into the aperture of the ear.
The vibrations being in this manner brought as close as possible to the organ of
hearing and prolonged vibrations entirely prevented, the articulation obtained is
very distinct and of a natural " timbre."
Instead of a stem or knob, a flat block may be used and attached in the manner
described and pressed against the cartilage of the ear when listening.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Richard Theiler and Meinrad Theiler in the Great Seal Patent Office
on the 22nd February 1883.
RICHARD THEILER and MEINRAD THEILER, both of 86, Canonbury Road
Islington, in the county of Middlesex IMPROVEMENTS IN TELEPHONE RECEIVING
APPARATUS
This invention partly relates to an improvement in and connected with the
telephone receivers in respect of which Letters Patent were granted to us dated
November the 10th 1881.
According to the said former Letters Patent, the lateral vibrations of an electro-
magnet when under the influence of a vibratory current, were communicated to a
tympan or diaphragm.
Now according to the present invention, the said lateral vibrations are commu-
nicated to a stem or knob of ivory, wood, horn or any other suitable substance of
such a shape that it can be conveniently inserted into the aperture of the ear or
pressed against the ear.
In carrying out our invention we do, however, not confine ourselves to making
use of the lateral vibrations only of an electro-magnet as described in the said
former Letters Patent, but may attach the said stem or knob to a tongue or bar of
soft iron fitted in such a manner that one end thereof can vibrate freely close to the
pole or poles of an electro magnet.
As a freely vibrating tongue or bar cannot, however, reproduce articulate speech,
we check or damp the vibrations by attaching the said stem or knob to the free end
The
of the tongue or bar and inserting the former into the aperture of the ear.
vibrations being in this manner brought as close as possible to the organ of hearing
and prolonged vibrations entirely prevented, the articulation obtained is very
distinct and of a natural timbre.
Instead of a stem or knob, a flat block may be used and attached in the manner
described and pressed against the cartilage of the ear when listening.
In order to explain our invention more fully, we will now proceed to describe the
same with reference to the accompanying drawing.
Fig. 1, shows that part of our invention which relates to an improvement in and
connected with the telephone receivers in respect of which Letters Patent were
granted to us dated November the 16th 1881. Instead of attaching the free end or
pole N, of the laterally vibrating electro magnet E, to a tympan or diaphragm, as
described in the said former Letters Patent, we now attach to the free end or pole N,
of the electro-magnet E, a stem or knob F', by means of a screwed pin S, as shown
in Fig. 1.
We generally make this stem or knob of one of the shapes shown in Figs 1, 2, 3
and 4 and find it advantageous to drill a hole through it as shown by the dotted
lines. The size and shape of this stem or knob may however be greatly varied and
also be made hollow instead of solid as shown. The sounds communicated to the
ear by means of this stem or knob are loudest when the latter is shaped as shown
in Fig. 1, that is to say when part of the knob F, can be inserted into the ear, but
perfectly distinct and sufficiently loud articulation is obtained with the stem shown
in Fig. 4, which ends in a flat knob. The electro-magnet E is firmly screwed into
the case A in the manner shown and the ends of the helix are generally connected
to a flexible conductor and the apparatus is connected with the line wire in
the usual manner. R, is a ring by which the instrument can be hung up when
done with,

page_text: Figs 5 and 6 show the construction of our telephone receivers in which the stem
or knob F herein before described is attached to the free end of a tongue or bar W,
of soft iron which is capable of vibrating close to the pole or poles of the electro
magnet E. The other end of this tongue or bar may be either fixed to one limb of
the electro magnet itself as shown in Fig. 5, or it may be fitted independently as
shown in Fig. 6.
Either the electro magnet E or the tongue W or both of them may be permanently
magnetised by induction, or consist of permanently magnetised steel. Fig. 7.
represents one of our telephone receivers provided with a permanent steel
magnet H, shaped in such a manner that the magnet serves as a handle to the
instrument.
When we use soft iron electro magnets only, we prefer to connect our apparatus
in the manner shown by Fig. 8, charging the said electro magnets by a local battery
and causing this charge to be varied inductively as shown.
To make the use of our telephone receivers as convenient as possible, we usually
provide the case A with a handle B, as shown in Fig. 6, this handle may be tubular
so that the flexible conductor C can be passed through it.
Having thus described and ascertained the nature and object of our said invention
and the manner of carrying the same into practical effect, we would remark in
conclusion that we do not intend to limit ourselves to the electro magnets and to
the stems or knobs described and shown on drawing but what we claim as our
invention is:
First. The use, in telephone receiving apparatus, of a sound conducting stem or
knob, substantially as described, such stem or knob being attached to, or in
communication with, an electro magnet or the armature of an electro-magnet.
Second, The use, in telephone receiving apparatus, of a stem or knob substantially
as described, for the double purpose of damping the vibrations of an electro magnet
or of a magnetic tongue or bar and communicating such vibrations to the ear.
Third. The Construction of telephone receiving apparatus substantially the same
as herein set forth and shown by Figs. 1, 5, 6 and 7.
In witness whereof, we, the said Richard Theiler and Meinrad Theiler have
hereunto set our hands and seals, this twenty second day of February in the
year of our Lord One Thousand, eight hundred and eighty three.
RICHARD THEILER (LS)
M. THEILER
(L.S.)