IMPROVEMENTS IN THE MANUFACTURE OF ARTIFICIAL TEETH AND THE BEDS AND PALATES FOR TEETH
Year: 1849

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
FELLOWS HARRINGTON, of Portsmouth, Dentist, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the First day of August,
One thousand eight hundred and forty-nine, in the thirteenth year. of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said George Fellows Harrington, my exors, adiñors, and assigns, Her especial
licence, full power, sole privilege and authority, that I, the said George
Fellows Harrington, my exors, adññors, and assigns, and such others as I, the
said George Fellows Harrington, my exors, adññiórs, or assigns, should at any
time agree with, and no others, from time to time and at all times during
the term of years therein' expressed, should and lawfully might make, use,
exercise, and vend, within England, Wales, and the Town of Berwick-upon-
Tweed, my Invention of "IMPROVEMENTS IN THE MANUFACTURE OF ARTIFICIAL
TEETH AND THE BEDS AND PALATES FOR TEETH;" in which said Letters
Patent is contained a proviso that I, the said George Fellows Harrington,.
should cause a particular description of the nature of my said Invention,.
and in what manner the same is to be performed, by an instrument*
in writing under my hand and seal, to be inrolled in Her said Majesty's'
High Court of Chancery within six calendar months next and immediately.
after the date of the said in part recited Letters Patent, as in and by
the same, reference being thereunto had, will more fully and at large.
appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
George Fellows Harrington, do hereby declare that the nature of my said
Invention, and the manner in which the same is to be performed, are fully
described and ascertained in and by the following statement thereof, reference
being to the Drawings hereunto annexed, and to the figures and letters
marked thereon, that is to say:-
My Invention consists :-
First, of improvements in the manufacture of artificial teeth when what are
called mineral teeth are used.
Secondly, my Invention consists of improvements in the manufacture of the
beds and palates for teeth and artificial palates where no teeth may be required
by the application of tortoiseshell. And,
Thirdly, my Invention consists of improvements in the machinery or
apparatus employed in the making of beds or palates for teeth. And in order
that my Invention may be most fully understood and readily carried into
effect, I will proceed to describe the means pursued by me.
Heretofore in manufacturing mineral teeth in sets or large pieces it has
been usual to take a cast of the mouth or part thereof of a patient, and to
obtain therefrom a model of the mouth or parts thereof, whether for the upper
or lower gums, and this model is handed to the maker of mineral teeth,
in order that he may make the teeth in accordance therewith, and the
workman makes the teeth with the surfaces which come next the gums as
nearly as may be to fit the guins, and formerly such teeth were made
without the interposition of beds or palates of gold or other material,
but in modern practice it has been usual for the makers of artificial
teeth to employ gold (and in some instances other materials) as beds
and palates for such teeth, and thus are sets or parts of sets of artificial teeth
made. Mineral teeth, heretofore, when to be combined with beds or palates,
have been made in like manner from the model of the mouth and the parts
or surfaces thereof which were to come next the gums. have been made in
accordance with the model of the interior of the mouth, and suitable to fit the
gums of the patient, and the gold to form the bed or palate has been stamped
into form, according to a model of the mouth obtained as before explained from
the particular patient for whom the set of teeth are intended. The mineral
teeth and the gold, having been made both to correspond with the mouth, they.
have had to be combined together, and this has been done by cutting away the
surface of the mineral teeth which is to come next the bed or palate of gold,
such cutting away requiring careful and accurate workmanship, and which is
more or less difficult, depending on the varied undulations in the gumis or

page_text: parts of the mouth which have to be covered by the beds or palates for mineral
teeth, being composed of a substance which is first moulded and then vitrified,
and it being a property of such substance to decrease in size to a considerable
degree in the process of firing, and as the form and undulations of each mouth
differs from all others, it has hitherto been found impossible to mould it so that
it shall exactly fit the intended bed or palate after the piece of mineral has
been vitrified; all which render the accurate fitting of artificial teeth a very
difficult art, and the same is comparatively seldom well done. Mineral teeth
have also been made in single teeth, and in small pieces of three or four teeth,
without reference to any particular mouth, but a sufficient substance of mineral
has been left at the base of each tooth or teeth to allow of its being cut away
to fit a particular mouth, or part thereof, so that the same description of
difficult workmanship is required in fitting as in cases where pieces of mineral
are made for a particular mouth. Now, according to the first part of my
Invention, I manufacture mineral teeth with the surfaces which come next the
palates or beds without reference to the nature of the particular mouth to
which they may afterwards be fitted, and cause the palates or beds to be made
on the one surface to correspond with the particular mouth to which artificial
teeth are to be fitted, and the other surface thereof to correspond with the
surface of the mineral teeth, so as accurately to fit the same, thus rendering
the making of such surfaces of the mineral teeth first to correspond with the
mouth, and then to cut away the same to allow for and adjust them to the bed
and palate introduced between the teeth and the mouth unnecessary. In
carrying out this part of my Invention, I would state that I have found, on
an extensive examination, that in the variation between extreme cases of
the mouths of persons (so far as the sets of teeth are concerned) there is not
a large difference, and that if four or five sets of teeth, slightly differing in
dimensions, be made, such a series will, if the palates and beds be well made,
be suitable for most if not all the cases which a dentist will be called on to
treat; and, in carrying out my Invention, I cause a series of distinct sets of
mineral teeth to be moulded, each set being but in a small degree less or
larger than another set, so that when a dentist is about to prepare for fixing
a set of teeth he will take a cast of the mouth, in order to make the palate
and bed correct to the mouth, and he will at once know which of the sized
sets will be the proper one for the particular case. But in place of taking the
cast of the mouth by the means of soft wax, placed in what are called
"model pans" of the ordinary kind, one part of my improvements consists
in using model pans or sets with teeth, or projecting surfaces of the dimen-
sions of teeth, so that a patient having two model pans or sets in the mouth

page_text: and the feeling and countenance of the patient will indicate whether the
height and diameter of the teeth, palates, and beds, are agreeable and
proper for the patient's case, by which means an exact measure for the set
of artificial teeth will be ascertained by the dentist, and at the same time
casts for obtaining models will be obtained; by such means the dentist,
if he record the dimensions, which he will be facilitated in doing by means of
the measuring apparatus hereafter explained, will be able to complete a set
of artificial teeth without in most cases requiring to see the patient more
than once.
DESCRIPTION OF MEASURING APPARATUS.
Figure 1 is a plan of the apparatus, and Figure 2 a front view of the same,
showing the mode of using the apparatus. Figure 3 is a plan and side view
of the measuring instrument separately. a is a plate carried by the lower
ends of the three uprights b, which are marked or graduated with divisions, as
shown. c is the measuring instrument (the three bars of which are also
graduated), which fits exactly on to the uprights b, so that when model pans
such as above described, or a model set, or a set of artificial teeth, are placed
upon the mould plate a', the dimensions may be very correctly ascertained and
recorded.
My improvement in the manufacture of palates and beds for teeth consists
in the use of tortoiseshell in their manufacture, and the process for doing
which, together with the machine or apparatus employed, I will now proceed
to describe.
DESCRIPTION OF THE SHAPING OR MOULDING APPARATUS.
Figure 4 shews a plan of the apparatus for compressing and moulding the
shell into the desired form for palates or beds; Figure 5, a longitudinal
section Figure 6, a transverse section through the dotted lines 1, 1.
Figure 7 shews the instruments or levers when open before operating by side
pressure; and Figures 8, 9, 10, 11, 12, 13, and 14 show the other parts of
the apparatus separately. a is a plate upon which the dovetail plate 6 slides.
bare holes in the slide 6 to receive the studs on the under side of the plate c,
to which are attached the moulds, models, or forms (in type metal) for the
beds and palates. The arms or levers d, d, are connected to the plate a by
the pin d passing through them, and thereby forming joints or axes upon
which they move, d³, d², are links which connect the levers & to the pressing

page_text: piece e; and d³, d³, are other links which connect the frame and screw f to the
levers d, so that when the screw f is turned the presser e is forced towards the
mould or model of the mouth (either the bed or the palate). The levers d
are drawn inwards by the connecting links d2 and d³. g. is a plate having
several holes to correspond with those in the plate a, and the two are firmly
screwed together by screws, as shewn. The plate g has an opening through.
it to receive the piece of cork g', which is pressed downward into the recess
formed around the mould and between the levers d by the die or presser h,
which corresponds with the opening in the plate g, there being screws g³ on
the plate g which pass through the flange on the upper surface of the pressing
instrument h, which is acted upon by the screw nuts g³ during the operation
of moulding. The mode of using this apparatus is as follows:-The plate a,
having the mould, model, or form fixed upon, is first connected to the levers d
and to the plate g by the pin d¹ passing through them; the two plates a and g
are combined together and secured by the screws, as shewn; a piece of
tortoiseshell cut to the desired form is next placed on the model, and the
piece of cork g' is introduced into the opening in the plate g; then the die or
presser is inserted, and screwed firmly down. The apparatus is to be put
into boiling water for fifteen to twenty minutes, when the die or presser h is
to be screwed down until the piece of cork is forced upon the shell into the
recess formed around the mould or model, as shewn in Figure 5. By turning.
the screw the presser e will advance towards the centre of the mould, and
the levers & will be drawn inwards so as to compress the shell in all directions;
and as the presser e approaches the mould the lower ends of the pins e¹ come
in contact with the angles formed by the projecting part of the plate b and
carry it and the mould or model forward. The apparatus being allowed to
moulded or shaped shell removed,
cool, the parts are to be separated, and the
in order to have the mineral or other teeth fitted to it, they being such as on
one side to fit the mouth and the other side to fit the recess or surface (what-
ever be its form) of the mineral teeth which is to come next it, any defect of
fitting being removed by scraping the tortoiseshell.
Having thus described the nature of my Invention, and the manner of
performing the same, I would have it understood that I do not confine myself
to the details as herein given, so long as the peculiar character of any part of
my Invention be retained. But what I claim is,―
First, the mode herein described of manufacturing artificial teeth where
mineral teeth are used, whereby the making of the teeth to the particular case,
or leaving a sufficient substance at the base of the tooth or teeth, to allow of
its being ground or cut away to fit a particular case, and the subsequent

page_text: cutting of the surfaces of the mineral teeth which come next the mouth,
in order to fit the beds and palates, are rendered unnecessary.
Secondly, I claim the manufacture of beds and palates for teeth, and of
artificial palates where no teeth are required, of tortoiseshell. And,
Thirdly, I claim the arrangement of machinery or apparatus herein
described.
In witness whereof, I, the said George Fellowes Harrington, have here-
unto set my hand and seal, this Twenty-ninth day of January, in
the year of our Lord One thousand eight hundred and fifty.