MENTS IN SOUND TRANSMITTING APPARATUS FOR DEAF PERSONS."
Year: 1880

page_text: PROVISIONAL SPECIFICATION left by Herbert John Haddan at the Office
of the Commissioners of Patents on the 5th February 1880. A communication
from abroad by Thomas Graydon, of Cincinnati, State of Ohio, United States
of America.
«
HERBERT JOHN HADDAN, of the Firm of Herbert and Company, Solicitors of
IMPROVE-
Patents, of 67, Strand, in the City of Westminster, Civil Engineer.
MENTS IN SOUND TRANSMITTING APPARATUS FOR DEAF PERSONS." A communi-
cation from abroad by Thomas Graydon, of Cincinnati, State of Ohio, United
States of America.
The Invention relates to apparatus for transmitting sound vibrations to the
auditory nerves of a deaf person through the teeth and bones of the upper jaw, as
a substitute to a certain extent for the ordinary organs of hearing. It consists in
an apparatus composed essentially of a diaphragm or plate of metal, vulcanised
rubber, or other suitable material, so mounted as to vibrate under impulses of
sound, and provided with means for adjusting the tension of the diaphragm. It
consists further in forming the diaphragm of such instrument in sections adapted
It also consists in the
to be folded or otherwise closed together when out of use.
combination with the diaphragm of special means hereinafter described for
regulating the tension of the diaphragm. The said diaphragm may be rectangular,
and composed of several parallel sections hinged together or circular, and composed
of sectors hinged together in the centre; it may be provided with a handle and
applied to the teeth direct, or with a stand and connected with a special mouth
piece by a cord. For varying the tension of the diaphragm the handle (placed
parallel with the folds of the latter) attached to the back and lower part of the
diaphragm is provided with an extension bar movable in the direction of its length,
and carrying at its upper extremity the lower fulcrum of a link movable in a
plane perpendicular to the diaphragm. The other (upper) end of the said link
forms a ring through which passes a cross bar attached with its two ends to the
upper part of the diaphragm. One (the lower) end of the latter is thus invariably
secured to the handle, while the other (upper) end is bent forward in proportion as
the extension rod is drawn out. The latter moves in a guide attached to the
The tension of
handle, and can be fixed in the required position by a set screw.
the diaphragm may also be regulated by a flat spring attached with its lower end
to the handle or its extension bar, and with its upper end to a cross bar or two

page_text: branches, the ends of which press upon the diaphragm either direct or by means
of a ring or enlarged foot. The extension bar may also be guided by a pin
attached to the handle and passing through a slot of the extension bar, and the
tension of the spring can be varied by a set screw pressing on the latter. If the
diaphragm is composed of sectors, the latter may overlap each other, and be
provided at their circumference with stops and guides to regulate and limit the
aliding motion of the segments. A circular diaphragm made of one piece may be
mounted in hooks or supports disposed preferably at equal distances on the
circumference and attached to a circular or other frame which is fixed to the
handle.