IMPROVEMENTS IN APPARATUS FOR THE TREAT- MENT OF CELLULOID AND VULCANITE IN THE MANUFACTURE OF DENTAL PLATES AND OTHER ARTICLES MOULDED UNDER HEAT AND PRESSURE, ALSO APPLICABLE TO OTHER USEFUL PURPOSES WHERE PRESSURE IS TO BE APPLIED IN A CLOSED CHAMBER
Year: 1878

page_text: LETTERS PATENT to Robert Brewster, of 25, Broad Street, Golden Square, in
the County of Middlesex, Manager of the Dental Manufacturing Company,
Limited, for the Invention of "IMPROVEMENTS IN APPARATUS FOR THE TREAT-
MENT OF CELLULOID AND VULCANITE IN THE MANUFACTURE OF DENTAL
PLATES AND OTHER ARTICLES MOULDED UNDER HEAT AND PRESSURE, ALSO
APPLICABLE TO OTHER USEFUL PURPOSES WHERE PRESSURE IS TO BE APPLIED
IN A CLOSED CHAMBER."
Sealed the 28th December 1878, and dated the 21st August 1878.
PROVISIONAL SPECIFICATION left by the said Robert Brewster at the Office
of the Commissioners of Patents on the 21st August 1878.
ROBERT BREWSTER, of 25, Broad Street, Golden Square, in the County of
Middlesex, Manager of the Dental Manufacturing Company, Limited.
"IMPROVE-
MENTS IN APPARATUS FOR THE TREATMENT OF CELLULOID AND VULCANITE IN THE
MANUFACTURE OF DENTAL PLATES AND OTHER ARTICLES MOULDED UNDER HEAT
AND PRESSURE, ALSO APPLICABLE TO OTHER USEFUL PURPOSES WHERE PRESSURE IS
TO BE APPLIED IN A CLOSED CHAMBER."
This Invention relates to certain improvements in apparatus known as "vul-
canizers," that is, a heating apparatus, a press, and an enclosed retort, known as
the "boiler," in which the receptacle or "flask" containing the moulds and plates
of celluloid or vulcanite are heated and subjected to pressure necessary for the
moulding of the plates.
The object of this Invention is primarily to effect the application of the necessary
pressure upon the mould "flask" without bringing the pressure to bear upon the
metal of the retort or boiler, which is less capable when heated of sustaining the
pressure; and secondly, to render the apparatus more compact and handy for use.
The apparatus consists of a heating chamber formed of sheet iron, and of a,
slightly conical columnar or of other convenient form, in the upper end of which is
set the retort or boiler, and in the lower part of this said heating chamber the
Povine 621

page_text: heating device (a Busen or other burner of ordinary or desired form) is arranged.
The retort or "boiler" is fitted with a steam safety valve, and has a hinged clamp
or spanner pivoted thereto, and provided with a centre screw, said hinged clamp
being sufficiently wide to allow of its being adjusted over a steam-tight cover, and
to admit of the centre screw acting directly upon the said steam-tight cover, to
hold same tightly and securely upon the boiler.
So far the apparatus is substantially the same as ordinary "vulcanizers," but of
improved arrangement of parts for the purpose of facilitating the adaption of the
screw press herein-after described and for rendering the apparatus more compact and
handy for use.
It should be remarked that the pressure applied by the centre screw of the
hinged clamp of the boiler is for the purpose only of holding the boiler cover
tightly upon its seating, and not for applying the pressure upon or to the mould
flask "as heretofore has been the case, whereby the metal of the boiler will be
relieved from the excessive pressure hitherto resulting in excess of or in addition to
the internal steam pressure.
"
The improved press and 'flask" holder, which is placed within the boiler, is
constructed and actuated as follows:-A metal frame or stirrup is to be made upon
the lower bar or foot plate, whereof the "flask" (prepared or made up in the
ordinary manner with the moulds and plates to be moulded and pressed) is to rest,
and through a tapped collar or nut piece of or in the arch of said stirrup frame a
centre press screw with a squared or T shaped head is passed and works so as to
press vertically upon the "flask " or mould.
Now
The pressure upon the mould "flask " to be effected by this screw will obviously
be exerted within the said stirrup press frame upon turning the press screw.
for effecting the turning of this said press screw a spanner, corresponding to or
fitting the squared or T shaped head of the press screw, is provided at the
extremity of a central pillar or projecting piece of metal mounted upon the under
side of the cover of the copper boiler so as to be free to turn around; and on the
upper end of this rotary spanner is a bevil gear wheel, which gears with and is
actuated by a second bevil gear wheel fitted upon a centre rod with a squared outer
end mounted in and working through a steam-tight stuffing box provided on the
cover or other portion of the boiler.
Ribs or projections are provided within the boiler to keep the press from turning
round when the power is applied to the press screw.
When the apparatus has been heated up to the required degree of heat the
pressure is applied to the "flask" by actuating the bevil gearing through the rod
passing through the stuffing box to turn the spanner actuating the centre press screw,
thus applying the pressure to the "flask" and its contents, such pressure, being exerted,
as before stated, within the stirrup press frame.
A thermometer or steam guage is provided on the cover or other part of the
boiler to indicate the degrees of heat or pressure of steam attained therein, which
will also indicate the moment at which the pressure is to be applied. A two-
handed key or spanner is applied to the end of the rod passing through the stuffing.
box, and to actuate the gearing to turn the press screw and apply the pressure.
For actuating the press screw I have described the means which I find to be
most readily applied, and which I prefer, but the rod and stuffing box for actuating
the internal press screw spanner may be inserted at any position of the lid or side
of the boiler, according to the means employed for securing the lid of the boiler on
its seating, and the internal gearing will be varied accordingly.
.The pressing and heating apparatus may be employed with slight modification of
the receiver or flask, in the preparation of tinctures and extracts, and as a less
degree of internal pressure will suffice within the boiler and none of the pressing
force is applied thereto, but is exerted only on the press contained therein, a glass,.
china,, or porcelain boiler may be employed for such purposes.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Robert Brewster in the Great Seal Patent Office on the 21st
February 1879.
ROBERT BREWSTER, of 25, Broad Street, Golden Square, in the County of
Middlesex, Manager of the Dental Manufacturing Company, Limited. " IMPROVE-
MENTS IN APPARATUS FOR THE TREATMENT OF CELLULOID AND VULCANITE IN THE
MANUFACTURE OF DENTAL PLATES AND OTHER ARTICLES MOULDED UNDER HEAT
AND PRESSURE, ALSO APPLICABLE TO OTHER USEFUL PURPOSES WHERE PRESSURE IS
TO BE APPLIED IN A CLOSED CHAMBER."
This Invention relates to certain improvements in apparatus known as "vul-
canizers," that is, a heating apparatus, a press, and an enclosed retort, known as the
boiler, in which the receptacle or "flask," containing the moulds and plates, or
articles of celluloid or vulcanite, are heated and subjected to pressure necessary for
the moulding of the plates or articles.
The object of this Invention is, firstly, to effect the application of the necessary
pressure upon the mould "flask" without bringing the pressure to bear upon the
metal of the retort or boiler, which is less capable when heated of sustaining the
pressure; and, secondly, to render the apparatus more compact and handy for use
and facilitate the operation of "cooking dental plates of celluloid or vulcanite, by
effecting the closing of the flasks during "cooking" and leaving the pressure still
applied after the clamp and flasks are removed from the boiler to make room
for a succeeding set of flasks.
In order that the Invention may be well understood I have hereunto annexed a
Sheet of Drawings illustrative thereof, wherein is shown the Invention applied to a
"vulcanizer" or apparatus for "cooking" celluloid or other dental plates.
Fig. 1 is an elevation of vulcanizer apparatus.
Fig. 2, a central section at right angles to Fig. 1.
Fig. 3, a view of under side of the boiler lid or cover.
Fig. 4, an elevation of the clamp or stirrup piece forming the internal press frame,
with two flasks therein, ready to be placed in the boiler.
Fig. 5, a plan or top view of Fig. 4.
The apparatus is shown constructed with a heating chamber A, formed of sheet
iron, and of a slightly conical, columnar, or other convenient form, in the upper end
of which is set the retort or boiler B, and in the lower part of this said heating
chamber the heating device C (a Bunsen or other burner of ordinary or desired form)
is arranged. The retort or "boiler" B is fitted with a steam safety valve D, and
has a hinged clamp E pivoted thereto and provided with a centre screw E¹, said
hinged clamp being sufficiently wide to allow of its being adjusted over a steam-
tight cover F, and to admit of the centre screw E acting directly upon the said
steam-tight cover F, to hold same tightly and securely upon the boiler. T is a
thermometer.
So far the apparatus is substantially the same as ordinary "vulcanizers,"
but of improved arrangement of parts, for the purpose of facilitating the adaptation
of the screw press herein-after described, and for rendering the apparatus more com-
pact and handy for use.
'
It should be remarked that the pressure applied by the centre screw E' of the
hinged clamp E of the boiler B is for the purpose only of holding the boiler cover F
tightly upon its seating, and not for applying the pressure upon or to the mould
flask," as heretofore has been the case, whereby the metal of the boiler will be
relieved from the excessive pressure hitherto resulting in excess of or in addition to
the internal steam pressure.
#
The improved press and flask holder, i.e., the clamp which is placed within the
boiler, is constructed and actuated as follows:-A metal press frame G, here shown
as of stirrup form, is employed upon the lower bar or foot plate G', whereof the
flask (prepared or "made up in the ordinary manner with the moulds and
"

page_text: plates to be moulded and pressed) is to rest, and through a tapped collar or nut
piece G² of or in the arch of said stirrup frame a centre press screw H, with a
squared or shaped head H¹, here shown T shaped, is passed, and works so as
that the foot of the press screw shall press vertically upon the "flask "
upon a press plate above the said flask.
cover, or
In the Drawings the press plate H2 is shown in position above the top flask, and
is loose from the press screw, but it may be attached loosely to the foot of the screw,
so as to allow of the same being turned.
The pressure upon the "mould flask " to be effected by this press screw H. will be
obviously exerted within the said stirrup press frame G upon turning the press
screw H. Now, for effecting the turning of this said press screw a slotted spanner
or "key" I, corresponding to or fitting the squared or T shaped head H¹ of the
press screw H, is provided at the extremity of a central pillar or projecting piece of
metal mounted upon the under side of the cover of the boiler, so as to be free to
turn around. In the Drawings this central spanner I is shown secured by a screw-
ended stud K screwed into the cover F, said spanner or key I working around the
smooth or plain portion between the head and screwed part of the said stud K. On
the upper end of this rotary spanner I is a bevel gear wheel L, which gears with
and is actuated by a second bevil gear wheel or pinion M, fitted upon a rod N made
with a squared outer end N¹, and said rod N works through a steam-tight gland
or stuffing box O provided on the cover of the boiler.
It will be obvious that the lid or cover F may be varied in shape, and this
stuffing box O and rod N may be fitted at other angle to the rotary spanner I, the
bevil gearing being varied accordingly.
Ribs or projections are provided, as at P, within the boiler, to keep the press
frame or clamp G from turning round when the power is applied to the press screw.
Any suitable stops will be provided for this purpose.
In use when the apparatus has been heated up to the required degree of heat,
which will be indicated by a thermometer, or be indicated and determined by a
regulating pressure gauge of ordinary or desired construction, the pressure will be
applied to the flask by actuating the bevil gearing through the rod N passing
through the stuffing box O to turn the spanner I, the slots whereof fit the head of
the centre press screw, and are of sufficient length to allow of the head H' sliding
within the spanner as it is turned, and thus actuating the centre press screw and
applying the pressure to the flask or matter between the press plates and to the
contents, such pressure being exerted as before stated and as is obvious within the
press frame G that is between the foot of the press screw H and the foot plate G¹
of the press frame.
One or more flasks may be operated upon for the "cooking" and moulding
process within the same press or clamp, and as convenient or desired, that is, two
or more flasks may be treated at the same time, two are shown in Fig. 5; and any
number of "charges," that is, clamps, and flasks, moulds, and plates, may be succes-
sively operated upon with the one "boiler" or beating device without allowing it to
cool down, as the pressure will remain constant upon the flasks within the clamps and
on the moulded articles until cool and set, and without danger of their yielding or
being damaged after, or by their removal from the boiler.
These pressure-retaining flask clamps may be varied by providing the press
plate H2 with articulated or with pivoted catches or spring catch pieces which will
gear with a rack or racks or stop piece formed upon the side pillars or portions of
the clamp. Thus when the pressure is applied upon the flask the catches or springs
will ride down the racks and prevent the pressure being removed when the clamp
is taken from the boiler and whilst the moulded "plates" or articles are cooling.
In this modification of my Invention the flasks, after being pressed together, are
held as well by the screw as by the catches, but this may be varied by causing the
flasks to be held by the catches alone, and in this case the screw action may be
provided, as in the old forms or kinds of vulcanizers where direct pressure is
applied.

page_text: A thermometer or steam gauge is provided on the cover or other part of the
boiler to indicate the degrees of heat or pressure of steam obtained therein, which
will also indicate the moment at which the pressure is to be applied; a two-handed
key or spanner, as at Q, is applied to the end N' of the rod N, passing through the
stuffing box O, and to actuate the gearing to turn the press screw and apply the
pressure.
For actuating the press screw I have described the means which I find to be
most readily applied and which I prefer to use in this class of apparatus; but, as
before stated, the rod N and stuffing box O for actuating the internal press screw
spanner I may be inserted at any position of the lid, or in some cases through the
side of the boiler, according to the means employed for securing the lid F of the
boiler on its seating, and the internal gearing will be varied accordingly. Again,
when the mouth of the boiler, the clamp E, and cover is at the side of the boiler
(to which arrangement no claim is made) the rod N will form a portion of the
spanner I, and the action upon the internal press G, H, will be direct instead of
through gearing. R is a ring supplied for convenience in lifting the lid or cover F.
This pressing and heating apparatus may be employed with slight modification of
the receiver or flask in the preparation of tinctures and extracts, and as a less
degree of internal pressure will in some cases suffice within the boiler and none of
the pressing force is applied thereupon, but is exerted only on the press contained
therein, a glass, china, or porcelain boiler may be employed for such purposes.
Again, this press-actuating device, consisting of the spanner I and rod N working
through the stuffing box O in a boiler or retort, and actuating the press screw
H, H, may be applied with advantage to retorts or boilers of the kind known as
digesters."
"
Having now described the nature of my said Invention, and given such directions
as will enable the same to be carried into practical effect, I claim,
-
1st. In a boiler, retort, or heating device the internal press G, G¹³, G², H, H¹,
actuated by a key piece or spanner I fitting the head of the said internal press
screw, said key piece or spanner I being actuated either direct by rod N, N', passing
through a stuffing gland O, or acting through gearing, for the purpose and in the
manner substantially as set forth, and shown in Figs. 2, 3, 4, and 5.
2nd. The "vulcanizer" apparatus for treating by heat and pressure dental plates
and other articles constructed and arranged in combination with the internal press
and flask-clamping device, as and for the purpose herein set forth, and shown by
the Drawings.
3rd. The use of a pressure-retaining clamp for pressing or closing flasks or
mould receptacles within a boiler or heating chamber, and for holding the charge
under pressure whilst cooling and after removal from the boiler or heating chamber,
as and for the purpose herein set forth.
In witness whereof, I, the said Robert Brewster, have hereunto set my hand
and seal, this Twentieth day of February, One thousand eight hundred
and seventy-nine
ROBERT BREWSTER. (L.S.)