IMPROVEMENTS IN TELEPHONES
Year: 1882

page_text: LETTERS PATENT to Stephen Mitchell Yeates, of Grafton Street Dublin
in the County of Dublin, Ireland for an Invention of IMPROVEMENTS IN
TELEPHONES
"
PROVISIONAL SPECIFICATION left by the said Stephen Mitchell Yeates
at the Office of the Commissioners of Patents on the 14th July 1882.
STEPHEN MITCHELL YEATES, of Grafton Street, Dublin, in the county of
Dublin, Ireland, "IMPROVEMENTS IN TELEPHONES
"3
My said Invention consists in improvements in telephones and instruments used
for the reproduction of articulate speech and musical sounds; and is designed to
effect the construction of telephone receivers so that the sounds produced are loud
and clear without the intervention of a tympanum or diaphragm.
For this purpose I provide an electro-magnet either straight or curved with a
rigidly fixed armature of soft iron brought close to either or both of the poles or
attached to one of them.
When a current is transmitted from the sending station and caused to traverse
the coils of the electro-magnet a sound is produced by the core and its armature,
and the magnet being attached to a suitable resonator or sounding board the sounds
transmitted become loud and audible.
This arrangement is also applicable for receiving and reproducing sounds of any
description from a distance, and also for receiving time signals and so forth.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Stephen Mitchell Yeates in the Great Seal Patent Office
on the 13th January 1883.
STEPHEN MITCHELL YEATES, of Grafton Street, Dublin, in the County of
Dublin, Ireland, "IMPROVEMENTS IN TELEPHONES
"
My Invention consists in improvements in telephones and instruments for the
reproduction of articulate speech and musical sounds; and is designed to effect the
construction of telephone receivers, so that the sounds produced are loud and
clear, without the intervention of a tympanum or diaphragm.
For this purpose I provide an electro-magnet either straight or curved with a
rigidly fixed armature of soft iron or other magnetic substance fixed close to either
or both of the poles or attached to one of them.
When a current is transmitted from the sending station and caused to traverse
the coils of the electro-magnet, a sound is produced by the core and its armature,
and the magnet being attached to a suitable resonator or sounding board the
sounds transmitted become loud and audible.
This arrangement is also applicable for receiving and reproducing sounds of any
description from a distance, and also for receiving time signals and so forth.
The accompanying drawings will more clearly illustrate the nature of my said
Invention and the manner of applying the same in practice :-
"
Fig. 1. shows an electro-magnet M and armature A; the electro-magnet being fixed
at one end as shown, or it may be arranged as represented in figs. 2, 3, and 4. The
electro-magnet and armature thus constructed is mounted on a suitable resonant
board or box as illustrated in fig. 5, by which means the sound produced is greatly
augmented while at the same time the box forms a convenient stand or handle for
the instrument. Or the instrument may be fixed within the box as shown in
fig. 6: or within a suitably formed cylinder or drum as shown in fig. 7:. whichever
arrangement may be found most convenient.
The action of the apparatus is as follows:-When a current of electricity from
the sending station traverses the coils of the electro-magnet a sound is produced
by the magnet and its armature.
Having thus described the nature of the said Invention and the manner of
applying same, I would have it understood that what I consider new and useful,
and therefore claim as the invention to be secured to me by the hereinbefore in part
recited Letters Patent is :-
Firstly. The construction and application of an electro-magnetic telephone with
a rigidly fixed armature attached to either or both poles as herein described and
Bet forth.
Secondly. An electro-magnetic telephone receiver with rigid armature fixed close
to the poles of the magnet but not attached as herein set forth.
Thirdly: An electro-magnetic telephone as herein described in which the cores of
the electro magnet or the armature or both are made of tempered steel permanently,
magnetized.
In Witness whereof I, the said Stephen Mitchell Yeates, have hereunto set
my hand and seal this Eleventh day of January, in the year of our Lord,