Apparatus for Shewing the Action of the Vocal Cords and the Thyroid, Cricold, and Arytenoid Cartilages in the Production of the Voice.
Year: 1893

page_text: Date of Application, 30th May, 1893-Accepted, 1st July, 1893
COMPLETE SPECIFICATION.
Apparatus for Shewing the Action of the Vocal Cords and the
Thyroid, Cricold, and Arytenoid Cartilages in the Production of
the Voice.
I, THOMAS CHATER, Professor of Voice Production and Singing, of Abbotts-
ford House No. 9 Finborough Road, in the Parish of St. Mary Abbotts,
Kensington, 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 particularly
described and ascertained in and by the following statement :-
My invention relates to an apparatus which shews the natural action of the
vocal cords, and the thyroid, cricoid and arytenoid cartilages under the influence of
their appropriate muscles and nerves in the production of the tones of the three
registers of the voice. I will proceed to describe the apparatus with reference to
the accompanying drawings, in which
Fig. 1 shews a plan of the complete apparatus.
Fig. 2 shews a plan of the same without the top cover A and with the mem-
branous substance f intended to represent muscles and tissue which connect the
thyroid with the vocal cords, removed ;
Fig. 3 shews a longitudinal section on line X X Fig. 1.
Figs. 4, 5 and 6 shew different positions of the vocal cords and other parts.
The apparatus is supposed to shew a horizontal section of the human larynx
just above and below the vocal cords, which are represented by the elastic bands a
the outline of the middle portion of the thyroid, being represented by the arched
piece b which is fixed to the base plate cat b' while the two ends are free to move;
the upper posterior edge of the cricoid is represented by the part d, and the bases
of the arytenoid cartilages are represented by the parts e, carried on the part d.
The latter is formed with a groove at d with which engages a hook-shaped part or
notch e' on the undersides of ee, these being kept engaged with the said groove
firstly by the pull of the elastic vocal cords a a and secondly by elastic cords I
passing through ee and secured to d. By this arrangement the parts ee are afforded
moveable fulcra on the arched rim of d, whereby they are capable both of assuming
varying angular positions relatively to each other, and of moving laterally towards
and away from each other.
The bands a a representing the vocal cords have their one end fixed to the apex
of the thyroid b, while their other ends are attached to the parts e representing the
arytenoid cartilages.
The thyroid bis formed of any suitable more or less hard elastic material, such
as cardboard, vulcanite whale bone &c. so that the free ends when drawn together
as will be presently described, will afterwards resume their original position. The
parts d and e are also of hard material, the part d being so attached to the base c
that it can rock to a slight extent thereon at d.
The parts ee are connected together at their lower end by an elastic band so
that they will always resume their normal position after approximation or
separation.
The movements which the several parts abd and e, are required to shew are as
follows:
1. The vocal cords a for ordinary quiet breathing are slightly separated as shewn
in Figs. 1 and 2, the space between them being called the glottis. When walking
they are moved slightly further apart, and when taking violent exercise or taking
a full and deep inspiration preparatory to the production of voice they are
separated widely as shewn at Fig. 4, after which for the production of tone they
are brought closely in contact, so as to be thrown into vibration by the expulsion of
air from the lungs, as shewn at Figs. 5 and 6.

page_text: 2. The parts d and e require to be moved towards and away from the apex of
part so as to either slacken or stretch the vocal cords, these movements being
effected by rocking the part d either backward or forward at d' upon its support.
3. The parts e also require to be moved on their supports on d either into
different angular positions or laterally away from or towards each other, as before
described, for separating or bringing together the vocal cords a.
4. The free ends of the part require to be approached towards each other
simultaneously with either the bringing into close contact of the vocal cords from
process to root only as at Fig. 5, or the bringing into contact of the vocal cords
and arytenoids as at Fig. 6.
For effecting these several movements, various mechanisms may be arranged,
the arrangement shewn in the drawing being only intended to serve as an example.
In this arrangement there are provided five rollers 1, 2, 3, 4, 5, the axes of which
are carried in the sides of the casing and which are provided externally with
buttons 1* 2* 3* 4* 5* for turning them.
Roller No. 1 is connected by cords g to bell cranks pivotted at ', the other
arms of which are connected by cords ' to the upper ends of the arytenoid
cartilages e, so that on turning the roller so as to put a strain on the cords this
will move the bell cranks so as to draw the parts e and consequently the vocal
cords a further apart, thereby increasing the opening of the glottis as at Fig. 4.
Roller No. 2 is connected by cords i to the lower ends of the parts e, so that on
turning the roller to put a strain on the cords i these turn the parts e upon their
fulera on d thereby bringing the vocal cords close together so as to close the glottis
as at Fig. 5.
Roller No. 3 is connected by cords g to the cricoid d so that on turning the
roller so as to strain the cords, the part d is rocked forward, together with the
parts e thereby slackening the tension of the vocal cords.
Roller No. 4 is connected by one set of cordsj to the part d and by another set
of obliquely placed cords & to the ends of the thyroid so that on turning this
roller so as to put a strain on the cords, the set will rock the parts d and e back-
wards thereby increasing the strain on the vocal cords a while at the same time the
cords draw the ends of the part b together.
Roller No. 5 is connected by cords m to bell cranks n pivotted at n¹ whose other
arms are connected firstly by cords o to the opposite ends of the part b, and
secondly by cords p to the opposite part e, so that by turning the roller the upper
parts of e and consequently the lower ends of a are drawn closely together, and at
the same time the ends of part bare drawn inwards, as shewn at Fig. 6, these
positions being intended to represent the action of the vocal cords, the arytenoids,
and the thyroid for the production of the upper register.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. Apparatus for shewing the action of the vocal cords and the thyroid, cricoid,
and arytenoid cartilages in the production of the voice, constructed and operating
substantially as described with reference to the accompanying drawings.
2. In apparatus for shewing the action of the vocal cords and other parts of the
larynx in voice production, the combination of the elastic bands a a representing
the vocal cords, the arched piece representing the thyroid and the parts d and e
representing the cricoid and the ary tenoid cartilages, the said parts being connected
to any suitable mechanical device whereby motion may be imparted to them in
imitation of their action in voice production, substantially as described with
reference to the drawings.
Dated this 30th day of Mar 1802
ABEL & IMRAY,
Agents for the Applicant.