AN IMPROVED APPARATUS FOR MOULDING PLATES OF CELLULOID, VULCANIZED INDIA-RUBBER, OR SIMILAR MATERIAL FOR ARTIFICIAL TEETH
Year: 1877

page_text: LETTERS PATENT to John Hutchens Gartrell, of Penzance, in the County of
Cornwall, for the Invention of "AN IMPROVED APPARATUS FOR MOULDING
PLATES OF CELLULOID, VULCANIZED INDIA-RUBBER, OR SIMILAR MATERIAL FOR
ARTIFICIAL TEETH."
Sealed the 12th April 1878, and dated the 27th October 1877.
PROVISIONAL SPECIFICATION left by the said John Hutchens Gartrell at the
Office of the Commissioners of Patents on the 27th October 1877.
JOHN HUTCHENS GARTRELL, of Penzance, in the County of Cornwall.
"AN
IMPROVED APPARATUS FOR MOULDING PLATES OF CELLULOID, VULCANIZED INDIA-
RUBBER, OR SIMILAR MATERIAL FOR ARTIFICIAL TEETH."
My Invention relates to improved apparatus to be used in the manufacture of
dental plates of celluloid, vulcanized india-rubber, or other like material.
The said apparatus comprises a flask or mould formed in two parts, and in which
are placed the teeth and the metal models of the plates, which are enclosed in a
setting of plaster of Paris.
Also a boiler, preferably constructed of phosphor or manganese bronze, and in
which the said flask is subjected to steam heat. This boiler has an aperture pro-
vided with a tight cover, and through which the flask is inserted into and removed
from the boiler. The latter is also provided with a plunger and screw, forcing the
top part of the flask down upon the bottom part, and holding the same while the
flask is kept in the boiler.
My Invention is designed to improve this apparatus, and render it more efficient
and convenient than heretofore, and consists in the novel features of construction,
as herein-after set forth, namely:-First. Providing the boiler with an aperture
fitted with a tight cover on one side of the said boiler. This cover is made of
phosphor or manganese bronze or other suitable material, and may be circular, oval,
or of any other convenient form. The said cover is secured and held in place by a
metal strap and screw. The said strap is pivotted or jointed to the sides of the
boiler, and may be turned on its pivots either across or away from the said cover,
[Prins 8d 1

page_text: The said screw is passed through the centre of the strap with its point opposite a
small countersunk portion of the cover, and by turning the said screw its point is
forced into the said countersunk portion, and the said cover is thereby secured
closely and tightly over the aperture in the boiler. The required tightness
of the joint around this aperture and cover is ensured by the use of lead or
other packing.
The bottom of the boiler is provided with ribs or bars on which the said flask is
supported.
Heretofore, in the boilers used for the above purpose, the plunger has been
separate or detached from the screw, whereby it is forced down upon the flask, and
no provision has been made for conveniently raising the said plunger.
But according to the second part of my Invention, I provide for the raising of
the plunger as follows:- I make the said plunger hollow, and form in its interior a
screw thread, and I form on the lower end of the screw a similar thread which fits
and works in the screw thread in the plunger. To prevent the turning of the latter
with the screw in the neck of the boiler, the said plunger has on one or more of its
sides a Hat portion which fits against a flat surface in the neck of the boiler;
or I may provide the said plunger with grooves or other devices for the same
purposes.
The said screw extends through a stuffing box properly packed with asbestos or
other suitable material, and fitted with a gland, whereby the said packing is com-
pressed around the spindle of the said screw in such a manner as to permit it to
turn freely while making the joint steam-tight. By having the plunger and screw
connected as above described, I ensure a perpendicular thrust on the top of the
flask by turning the screw in one direction; while by turning the said screw in the
opposite direction, the plunger will be raised from the said flask.
The outer end of the screw rod or spindle is provided with a lever or hand wheel,
whereby it may be conveniently manipulated.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Hutchens Gartrell in the Great Seal Patent Office on the 26th
April 1878.
"AN
JOHN HUTCHENS GARTRELL, of Penzance, in the County of Cornwall.
IMPROVED APPARATUS FOR MOULDING PLATES OF CELLULOID, VULCANIZED INDIA-
RUBBER, OR SIMILAR MATERIAL FOR ARTIFICIAL TEETH."
• 1. P
My Invention relates to improved apparatus to be used in the manufacture of
dental plates of celluloid, vulcanized india-rubber, or other like material.
The said apparatus comprises a flask or mould formed in two parts, and in which
are placed the teeth and the metal models of the plates, which are enclosed in a
setting of plaster of Paris.
Also a boiler, preferably constructed of phosphor or manganese bronze, and in
which the said flask is subjected to steam heat. This boiler has an aperture provided
with a tight cover, and through which the flask is inserted into and removed from
the boiler. The latter is also provided with a plunger and screw, forcing the top
part of the flask down upon the bottom part and holding the same while the flask
is kept in the boiler.
My Invention is designed to improve this apparatus and render it more efficient
and convenient than heretofore, and consists in the novel features of construction,
as herein-after set forth, namely:-First. In providing the boiler with an aperture
fitted with a tight cover on one side of the said boiler; and, secondly, in a hollow
plunger and screw for forcing and holding the top part down upon the bottom part
of the flask in the boiler.
It also consists in the details of construction and combination of parts as herein-
after set forth.
In the accompanying Drawings,-
Figure 1 is a vertical section of an apparatus, embodying my Invention.
Figure 2 is a horizontal section on the line x, x, Figure 1.
Figure 3 is a vertical section, illustrating a modification of the said Invention,
herein-after described.
The remaining Figures are herein-after described.
Like letters indicate the same parts throughout the Drawings.
at c.
The flask A is formed in two parts a, a', in which are placed the teeth and the
metal models of the plates, as shewn at b, enclosed in a setting of plaster of Paris
These metal models or moulds are preferably formed of an alloy of pure tin
and antimony. The boiler B, in which the said flask A is subjected to steam heat,
is preferably constructed of phosphor or manganese bronze, and provided at the
bottom with ribs or projections C, whereon the said flask rests.
This boiler has in
one side an aperture provided with a tight cover D, and through which the flask is
inserted into and removed from the boiler B. The latter is also provided with. a
plunger E and screw F for forcing the top part a of the flask down upon the bottom
part u', and holding the same while the said flask is kept in the boiler. The cover
D is made of phosphor or manganese bronze or other suitable material, and may be
circular, oval, or of any other convenient form. The said cover is secured and held
in place by a metal strap d and screw . The said strap is pivotted or jointed to
the sides of the boiler, as shewn at 2, and may be turned on its pivots to set it
either across, that is to say, in front of the said cover D, or to one side of the same.
The said screw d¹ is passed through the centre of the strap d, and when the said
strap is turned or set centrally in front of or across the cover D, the point of the
screw will be opposite a small countersunk projection d³ of the cover D; and by
turning the said screw in the proper direction its point is forced into the cavity in
this projection, and the said cover is thereby held closely and securely over the
aperture in the boiler B. The required tightness of the joint around this aperture
and cover is ensured by the tongue and groove, and by the use of lead or other
packing, as shewn at d.

page_text: •
'
The ribs or bars C at the bottom of the boiler are formed and arranged in such
a manner as to support the flask without preventing access of the steam to the
same.
Heretofore, in the boilers used for the above purpose, the plunger for forcing and
holding down the top part of the flask has been soparate or detached from the screw,
whereby it is forced down, and no provision has been made for conveniently raising
the said plunger.
But according to my Invention, I provide for the raising of the plunger E as
follows: I make the said plunger hollow, and form in its interior a screw thread at
e, and I form on the lower portion of the screw Fa similar thread which fits and
works in the screw thread in the plunger. To prevent the turning of the latter
with the screw in the neck b* of the boiler B, the said plunger has on one or more
of its sides a flat portion e¹, which fits against a flat surface b' in the neck of the
boiler, as shewn in Figure 2; or I may prevent the turning of the said plunger,
while permitting it to move end wise in the neck of the boiler, by providing the said
plunger with a longitudinal groove or channel, and fixing in the neck of the boiler
a stud or feather projecting into the said groove; or I may use other suitable means
or devices for the same purposes.
The said screw F extends and works through a double gland G; the outer part
G¹ of this gland screws into the neck b* of the boiler down upon the collar F¹ of the
said screw, and prevents endwise movement of the said screw, but does not prevent
its revolving. The other part G2 of the gland compresses the packing around the
neck of the screw in such a manner as to permit it to turn freely, whilst making
the joint steam-tight. The endwise movement or displacement of the screw F
being thus prevented, it is obvious that by having the plunger E attached to the
screw F by the screw thread as above described, I ensure a perpendicular thrust on
the top of the flask A, by turning the screw in one direction; while by turning the
said screw in the opposite direction, the plunger will be raised from the said Hask.
I prefer to form the lower end of the plunger E with a flange E¹, to ensure a more
even pressure upon the top of the flask.
The outer end of the screw rod or spindle is provided with a lever or hand wheel H,
whereby it may be conveniently manipulated.
In Figure 3 I have shewn the boiler B containing two flasks A, one placed upon
the other. In other respects this apparatus is similar to that shewn in Figures 1
and 2 of the Drawings.
In Figures 1 and 3 it will be seen that I have shewn the flasks or moulds A with
two parts or sections a, a¹, just as they are inserted into the boiler B, and before
pressure has been applied by means of the said screw and plunger to force the top
part or section a down upon the other part a'. By applying this pressure the
moulds or flasks will be closed by forcing down the top part until its shoulders a²
rest upon the shoulders a³ of the bottom part a' of the flask. The two models are
also brought together by this operation, and the mould for the plate thereby accurately
obtained.
Figure 4 is an elevation; and Figure 5, a vertical section of a gas regulator fitted
to the boiler, whereby the quantity of gas conveyed to the gas burner for heating
the said boiler is regulated or controlled by the pressure of steam within the
boiler.
It is necessary in moulding and hardening celluloid or vulcanite that the temper-
ature within the boiler should be kept as uniform as possible. The manner in which
I accomplish this object I will now proceed to describe.
The regulator is shown detached from the boiler, but may be readily made fast to
the same by means of the screw K; formed upon the lower part of the regulator L
is a circular tube or case, secured to the part K by the screw coupling M; this case
forms a closed chamber N, into which the gas enters by the inlet pipe O, and the
gas escapes from the chamber through the outlet pips P, and thence passes through
an india-rubber tube to the gas burner placed under the boiler.
The passage of the gas to the burner is controlled or regulated by the automatic

page_text: arrangement herein-after described and contained in the closed chamber, the said
regulating arrangement being put into operation by the pressure of the steam in the
boiler.
Through the centre of the lower part K of the regulator is fitted a rod or piston Q
projecting into the steam space in the boiler; the upper end of this piston Q is
enlarged, as shewn at Q¹, and is surrounded by a spiral spring Q³. This enlarged
part Q carries a pad or valve R. The pressure of steam in the boiler acting on the
lower end of the said piston forces it upwards, thereby compressing the spring Q³
until the valve R is brought in contact with the end P' of the pipe P, so as to
partially cut off the supply of gas to the burner. As the temperature in the boiler
sinks, the pressure on the piston Q diminishes, and the latter is withdrawn from the
pipe P by the spring, thereby allowing a larger supply of gas to the burner. In
this manner a uniform heat can be kept in the boiler during the process of moulding
and vulcanizing the celluloid or india-rubber. The pipe P is made adjustable so as
to be raised or lowered; as the heat in the boiler is required to be greater or less a
milled headed screw P2 clamps and receives the pipe P after it has been moved in or
out to the distance required. The piston Q has steam packing compressed around it
near its upper end to make it steam-tight.
Figures 6 and 7 show a modified form of this gas regulator, Figure 6 being a
side elevation, and Figure 7 a vertical section. In this form the steam pressure acts
upon a corrugated metal disc S, through a bent tube in communication with the
steam space in the boiler. The deflection of the disc S moves a lever T; this lever
in turn moves a second lever U, which second lever carries a valve V on its end to
effect the closing of the outlet pipe. A flat steel spring W acts against the second
lever to press it back from the mouth of the outlet pipe as soon as the heat in the
boiler sinks. The outlet pipe X is adjustable in the same manner as the pipe in
Figures 4 and 5, and is clamped with a milled headed nut to secure the same.
In Figure 8 I have shewn in perspective a gas burner for heating the boiler and
melting the metal for making the metallic moulds above described. An india-rubber
tube which conducts the gas from the gas regulator to this burner is attached to the
tube A*, and the gas passes through this tube into the air chamber B*. The
compound of gas and air then enters the circular chamber formed in the bottom of
the burner at a tangent. This arrangement gives this gas and air an eddying
motion round the chamber, thoroughly mixing it when it escapes to the top of the
burner, passing through holes made in the conical projections 6*, and burning with a
blue flame. In the centre of the part forming the top of the burner is a hole to
receive the stem or pin of a "spider" C*, which fits loosely over the top of the burner,
and forms a holder for the ladle in which to melt the metal for the moulds; the
gas burner can be used with or without this "spider" as required.
Having thus fully described my said Invention, and the manner of performing the
same, I wish it understood that I claim,-
First. The boiler constructed with the aperture at one side of the same provided
with a cover, which may be tightly closed and secured, and readily opened, as above
set forth and for the purpose specified.
Second. The hollow plunger fitted to slide vertically without capability of
rotation, and connected with a screw which extends through the double gland or
other suitable device in combination with the collar on the said screw, making the
same steam-tight in the neck of the boiler, and preventing end wise movement of
the said screw while permitting its free rotation, so that the said plunger may be
raised and lowered without disconnecting it from the screw, as above set forth and
for the purpose specified.
Third. The apparatus (for moulding plates of celluloid or the like for artificial
teeth) comprising the boiler constructed as shewn, and provided with the side
aperture, and appliances for opening and closing the same, and with the means for
supporting the flask, and the devices for pressing down and holding the top part
of the flask, as shewn in Figures 1 and 2 of the Drawings, and as above set forth.

page_text: Fourth. The modification of the said boiler, whereby it is constructed to receive
two flasks as above set forth.
.:
In witness whereof, I, the said John Hutchens Gartrell, have hereunto set
my hand and seal, this Twenty-third day of April, in the year of our
Lord One thousand eight hundred and seventy-eight.
JOHN HUTCHENS GARTRELL. (L.S.)