DISLAIMER AND MEMORANDUM OF AL
Year: 1878

page_text: TEETH," dated the 13th December, A.D. 1878.
DISCLAIMER AND MEMORANDUM OF ALTERATION proposed to be
entered by the said John Hutchens Gartrell.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters Patent
dated 13th December, in the year of our Lord One thousand eight hundred and
seventy eight, in the forty second year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto me, the said John Hutchens Gartrell, my executors,
administrators, and assigns, the sole privilege of making, using, exercising, and
vending within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, the said Invention of "IMPROVEMENTS IN APPARATUS
FOR THE MANUFACTURE OF PLATES FOR ARTIFICIAL TEETH," for and during the
term of fourteen years thence next ensuing :
And whereas I, the said John Hutchens Gartrell, in pursuance of a proviso
contained in the said Letters Patent, did within six calendar months next and
immediately after the date of the said Letters Patent cause a Specification of the
said Invention to be filed in the Great Seal Patent Office:
And whereas since the filing of the said Specification I have been advised that
by reason of the ambiguity of certain words in the description thereof, the statement
of the nature of the Invention may be construed to mean more than is included in
the said Invention, and that certain portions of the Invention described and claimed
in the said Specification were not new as to the public knowledge and use thereof
at the date of the said Letters Patent :
NOW KNOW YE, therefore, that I, the said John Hutchens Gartrell, by and with
the consent of Her Majesty's Solicitor General, do alter and amend the said
Specification as follows, that is to say, referring to the Queen's Printers' copy of
the said Specification, and to page 5 thereof, I strike out of line 7 the word "for,"

page_text: and insert the words "used in," and I strike out of line "8" the word "vulcanized."
In page 6 I strike out the whole of the matter in line 41, and the sixteen following
lines, and on page 7 I strike out lines 1 and 2; in line 17 I substitute for the
word "boiler" the word "burner," and I strike out of line 37 the words " whereby
"I dispense with the," and the whole of the matter in lines 38 and 39; and out
of line 40 all but the concluding words "but I claim," and I insert after the words
"herein described" in line 37 the following disclaiming clause:-" Moreover I am
aware that it has been proposed to use apparatus provided with separate instru-
«
"
"
WICH CHOH Oherefore do not claim as part of my invention any
" combination of separately constructed instruments, such as a steam pressure
gauge or indicator, and a fluid supply regulator, or any apparatus or instrument
“for these purposes which is not complete in itself, that is to say, which does not
embody in itself the parts necessary for performing the two functions of indicating
"the pressure and regulating the supply of the fluid.” I also strike out line 41,
and the whole of the following matter to the end of line 50, including the first and
second claiming clauses. I also strike out the fourth claiming clause, and I
renumber the remainder of the claiming clauses consecutively.
And on page 8,
line 1, after the word "boiler" I insert the word "substantially," and in line 2 I
strike out the words "or any modification of a combined gas-regulator or regulating
"valve and ;" and in line 3 I strike out the words steam-pressure-gauge or
indicator," and insert the word "and" before the word "operating."
And in order that the effect of the said Disclaimer may be fully understood I
annex a copy of the Specification as it will appear when such Disclaimer and
Memoranduin of Alteration have been made, omitting the introductory and con-
cluding clauses thereof.
"
"
"
My Invention relates to improvements in apparatus used in pressing, moulding,
" and vulcanizing plates of celluloid, india-rubber, or similar material for artificial
teeth, and comprises devices for regulating the flow of gas for heating the
"vulcanizer and indicating the pressure of steam within it.
"
<
«
"
My Invention is illustrated in the accompanying Drawings, in which
Figure 1 is a perspective view of the said apparatus.
Figure 2 is a vertical section of a vulcanizing apparatus or boiler provided
" with various devices to be used for the purpose of my Invention, as hereinafter
" described.
«<
Figure 3 is a vertical section illustrating various modifications of the said
" devices.
«
<
Figure 4 is a plan or top view, and Figure 5 is a side elevation of a holder or
clamp, and illustrate the method of securing the flasks in the same, as hereinafter
described.
"
Figures 6, 7, 8, 9, 10, 11, illustrate my improved combined gas-regulator and
pressure-indicator.
Like letters indicate the same parts throughout the Drawings.
"The said apparatus comprises various novel features of construction, as hereinafter
"set forth, namely:-First, providing the boiler with a peculiar clamping apparatus
" to receive the flasks containing the material to be moulded, and vulcanized for
"dental plates. This clamping apparatus or clamp is operated by a device fitted
"to the lid or cover of the boiler. The said lid or cover is secured and held in
place by three levers and a screw-collar. The clamp-frame is constructed of
" iron or other suitable metal, and is so formed that it may be dropped into the
boiler with the flasks, and removed again when the process of moulding and
vulcanizing is completed."
<
"
"
"6
In Figure 2, a is the boiler, which is constructed of cast bronze or other

page_text: 16
"suitable material, and is preferably cylindrical in form; b is the clamp frame or
clamping apparatus to receive the flasks c, containing the material to be moulded
"and vulcanized for dental plates, and which is constructed of iron or other suitable
"metal, and is secured to the lid or cover and so formed that it may be inserted
"into the said boiler with the flasks c, and removed again when the process of
moulding and vulcanizing is completed. The spindle e is passed through a
"stuffing box f' in the lid or cover f of the boiler a, the said stuffing box being
"fitted with a screw cap f* and gland f³, which can be screwed down to compress
"the packing and make a steam-tight joint around the said spindle. The lower
"end of the latter is connected with the plunger f*. The latter is formed with a
"flange or foot, which rests on the flask, and by turning the screw spindle e, the
"said plunger can be forced down upon or raised from the flask.
<<
"
"The lid or cover f of the boiler is secured in its place by a novel device
consisting of a set of levers g, preferably three in number, and a screw-collar h.
"The said levers are secured at their lower ends by steel pins g' passing through
"them and into lugs or projections a¹ on the rim of the boiler a, or are otherwise
"fitted to turn on pivots on the said boiler. The said levers g can be turned over
"to rest upon the lid f with their ends under the said screw-collar h, which is
provided with handles h', or other convenient means for screwing it down upon
"the ends of the aforesaid levers g, and exerting upon them the required pressure
"to hold the lid f down, suitable packing being provided between the said lid and
"the surface on which it rests to ensure a steam-tight joint. In order to open
"the boiler, the collar h is screwed back or away from the levers g, thereby
simultaneously releasing the entire set of them and leaving them free to be
"turned over on their pivots g¹ clear of the lid f, which can then be lifted off by
"means of the aforesaid handles h¹.
"
"
"
This apparatus is very advanteous in working with celluloid, as it is then
necessary to allow the flasks to c down gradually under pressure; by having
"the clamp separate from the boil in the manner described, the said clamp can
"be removed with the flasks in it and placed aside to cool down altogether, while
"another clamp can be placed in the boiler, and another set of flasks worked
"without delay. This object is greatly facilitated by constructing the spindle and
screw in the manner hereinafter described.
"
"
"
"
In some instances I modify the construction of my improved apparatus, as
"shewn in Figures 3, 4, and 5, in such a manner that the clamp b is so operated by
"the spindle e and screw d, that the flasks c within the same are closed by the'
said clamp being drawn upwards instead of being pressed downwards, as in the
apparatus shewn in Figure 2. The advantage gained by this modified arrangement
is, that I draw away the flasks from the bottom of the boiler and so prevent an
" undue heating of the lower flask, which being the nearest to the part of the
" boiler receiving the heat of the atmospheric burner is subjected to greater heat
"than the upper flask. This purpose is effected by making the clamp b in two
parts b', 6, namely, the frame and the top part, and which are operated to close
"the flasks in the following manner:-The frame b', in which the flasks are placed
" to be closed for moulding the celluloid or rubber plates, is supported by the
screw d by means of the collar d* formed upon the lower end of the same, and
free to turn in a recess formed for the same in the under side of the upper part
"of the said frame. The upper part 62 of the said clamp has a central hole with
a thread cut in it to receive the screw d. It is also provided with pins b³,
(preferably three in number), which pass freely through holes b* in the top of
"the clamp-frame b¹, the lower ends of the said pins resting upon the top of the
upper flask. The screw d in this modification of my Invention is provided with
a square, hexagonal, or other shaped opening in its upper end, into which the
similarly shaped end of the spindle e fits, and by turning the said spindle by a
lever or handle placed upon its upper end, the screw d, which has preferably a left
"hand thread cut upon it, is screwed upwards into the neck of the lid f, and draws
«
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"
&
"
"

page_text: ""
"the frame b¹ up with it, but as the flasks c are stopped by the pins 63 on the
upper part 2 of the said flask, and thereby kept from ascending with the frame,
pressure is produced between the two parts 61, 62, of the said clamp and upon the
"flasks c to close the latter.
«
"
r
"The upper part 6 of the said clamp is kept from turning with the screw d
by providing it with a groove or grooves 6 to engage with a projection or
projections inside the boiler.
"Another novel feature of my apparatus is the combined indicator and
"regulator.
"
"
"
"
;
I prefer to construct this part of my apparatus as shewn in Figures 6, 7, 8, 9,
"10, 11; Figures 6 and 7 are front and rear elevations; Figures 8 and 9 are
"similar elevations with the parts in different positions; Figure 10 is a transverse
"section on the line x, x, Figure 7; Figure 11 is a side view. I use a case or
"box i, resembling that of an ordinary steam-gauge, and provided with a dial *
" enclosed by a glass face. Over the dial is placed an index finger; which acts to
" indicate the pressure of steam in the usual manner. In combination with
"this index finger, and central with the axis thereof, I provide at the back of the
case a disc k, which has a neck or tube k*, to which is connected the gas inlet pipe l.
"Within this tube or neck, which forms the valve-chamber, is arranged the valve l¹
this valve is arranged near the mouth of the outlet pipe m which extends through
the side of the valve-chamber. The gas enters the valve-chamber through the
"inlet pipe L, and when the said valve is open, as shewn at Figure 7, the gas
passes freely through the said chamber and pipe m to the burner. But the said
"valve is carried on the spindle or axis of the said index finger, or is arranged
"in combination with a small arm on the said spindle, so that the said spindle or
arm will move the aforesaid valve 1. and close, or nearly close, the same when
"the desired pressure in the boiler is reached. The disc k is also provided with
a pointer o, and the parts above described are so arranged relatively to each
"other, that when this pointer is set to any figure on the dial i*, and the steam-
pressure reaches a degree corresponding with this figure, that is to say, when
"the position of the finger coincides with that of the pointer, the valve
"close the pipe m and thereby cut off the free supply of gas to the heater.
<<
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"
16
"
"
"
"
will
"It will be seen that by this arrangement of the indicator and regulator the
quantity of gas supplied to the burner of the vulcanizer is regulated by the
pressure, and according to the desired pressure, of the steam in the boiler, and
"the same instrument by a hand on a dial shows the pressure in the said boiler.
Having thus fully described my said improvements, and shown how the same
may be conveniently and advantageously carried into practice, I wish it under-
"stood that I am aware of there having been already in use in apparatus for
" manufacturing dental plates a clamping device which has a frame for holding the
"flasks separate from the boiler, so that the said frame with the flasks securely
" held in it can be placed in or removed from the boiler, I therefore do not claim this
"device broadly or irrespective of the novel features herein described; moreover, I
am aware that it has been proposed to use apparatus provided with separate
" instruments, one for controlling or regulating the supply of gas or other fluid, and
"another for indicating pressure, and that such instruments have been used in
"connection with each other; I therefore do not claim as part of my Invention any
" combination of separately constructed instruments, such as a steam pressure guage
or indicator and a fluid supply regulator, or any apparatus or instrument for
"these purposes, which is not complete in itself, that is to say, which does not
embody in itself the parts necessary for performing the two functions of indicating
"the pressure and regulating the supply of the fluid, but I claim,-
"
«
"
"First. In combination with the said boiler and the cover, the pivotted levers
"
" and screw-collar arranged and operating as and for the purpose specified.
Second. The apparatus or means whereby I provide for the regulation of the
quantity of gas supplied to the burner according to the desired pressure of steam
«

page_text: "in the boiler, substantially as shewn in and described with reference to Figures 6
"to 11 of the Drawings, and operating as and for the purposes specified."
In witness whereof, I, the said John Hutchens Gartrell, have hereunto set my
hand and seal, this Eighteenth day of February, in the year of our Lord
One thousand eight hundred and eighty one.
I hereby grant my fiat, giving leave to the within named John Hutchens
Gartrell, to file in the Great Seal Patent Office, with the Specification to which the
same relates, the above written Disclaimer and Memorandum of Alteration, subject
to the condition below written.
THE CONDITION HEREINBEFORE REFERRED TO.
No action to be brought against the Dental Manufacturing Company in respect
of the manufacture, sale, or use of any apparatus constructed prior to this date, or
against any person who has purchased the same from them prior to this date, in
respect of any user of the apparatus so purchased.
A list to be furnished identifying such apparatus.
FARRER HERSCHELL,
14th February 1881.

page_text: LETTERS PATENT to John Hutchens Gartrell, of Penzance, in the County of
Cornwall, for the Invention of "IMPROVEMENTS IN APPARATUS FOR THE
MANUFACTURE OF PLATES FOR ARTIFICIAL TEETH."
Sealed the 25th February 1879, and dated the 13th December 1878.
PROVISIONAL SPECIFICATION left by the said John Hutchens Gartrell at
"IM-
the Office of the Commissioners of Patents on the 13th December 1878.
JOHN HUTCHENS GARTRELL, of Penzance, in the County of Cornwall.
PROVEMENTS IN APPARATUS FOR THE MANUFACTURE OF PLATES FOR ARTIFICIAL
TEETH."
My Invention relates to improvements in apparatus for making the moulds and
pressing, moulding, and vulcanizing plates of celluloid vulcanized india-rubber or
similar material for artificial teeth and other purposes, and comprises devices for
regulating the flow of gas for heating the vulcanizer, and indicating the pressure of
steam within it.
The said apparatus comprises various novel features of construction, as hereinafter
set forth, namely:- First, providing the boiler with a peculiar clamping apparatus
to receive the flasks containing the material to be moulded and vulcanized for
dental plates. This clamping apparatus or clamp is operated by a device fitted to
the lid or cover of the boiler. The said lid or cover is secured and held in place by
three levers and a screw collar. The clamp frame is constructed of iron or other
suitable metal, and is so formed that it may be dropped into the boiler with the
flasks and removed again when the process of moulding and vulcanizing is com-
pleted. The said clamp is provided with a screw having a metal disc or collar on
its lower end which presses upon the flasks. The said screw has in its upper end a
hole having teeth on each side of the hole. Into this hole the end of the spindle
fits, the same being also provided with teeth formed on each side of it to correspond
with the teeth in the hole; these teeth permit the end of the said spindle to enter
the hole in the screw and pass straight to the bottom thereof, when by giving the

page_text: said spindle a quarter of a turn, the teeth on the spindle become locked with the
teeth in the hole, and then when the spindle is turned by its lever or handle it
turns the said screw with it, and the same is thereby screwed through the top of
the clamp to produce pressure upon the flasks and close them. The said spindle is
passed through a stuffing box provided in the lid or cover of the boiler, and this
stuffing box is fitted with a screw-cap and gland which can be screwed down to
compress the packing and make a steam tight joint around the said spindle. Instead
of providing teeth as above described on the said spindle it may be formed with a
key to fit a key-way cut in the hole of the screw, or the end of the said spindle
may be made square to fit a square hole in the said screw.
The lid or cover of the boiler is clamped in its place by a novel device consisting
of a set of levers (preferably three) and a screw collar. The said levers are secured
at their lower ends by steel pins passing through them and into luge or projections
on the rim of the boiler, or are otherwise fitted to turn in pivots on the said boiler.
The levers can be turned over to rest upon the lid with their ends under the said
screw collar. This collar is provided with two handles or other convenient means
for screwing it down upon the ends of the said levers and exerting upon them the
required pressure to hold the lid down. Suitable packing is provided between the
said lid and the surface on which it rests to ensure a steam tight joint under this
pressure; to open the boiler the said collar is screwed back or away from the levers,
thereby simultaneously releasing the entire set of them and leaving them free to be
turned over on their pivots clear of the lid, which can then be lifted off by its
handles.
This apparatus is very advantageous in working with celluloid, as it is then
necessary to allow the flasks to cool down gradually under pressure; by having the
clamp separate from the boiler, in the manner described, the said clamp can be
removed with the flasks in it and placed aside to cool down altogether, while another
clamp can be placed in the boiler and another set of flasks worked without delay.
This object is greatly facilitated by constructing the spindle and screw in the manner
above described.
In some instances I modify the construction of the said clamp as follows, that is
to say, it is so constructed that it is closed by being drawn upwards instead of
being pressed downwards. The advantage gained by this modified arrangement is
that I draw away the flasks from the bottom of the boiler, and so prevent an undue
heating of the lower flask, which being the nearest to the part of the boiler receiving
the heat of the atmospheric burner is subjected to greater heat than the upper
flask. This purpose is effected by making the clamp in two parts, namely, the frame
and the top part, which are operated to close the flasks in the following manner.
The frame in which the flasks are placed to be closed for moulding the celluloid or
rubber plates is made fast to the screw by means of a bolt passed through the
centre of the upper end of the said frame into the end of the said screw. This bolt
has a head which is free to revolve in a recess made for it in the underside of the
top of the frame, but is kept from turning in the end of the screw. The upper part
of the said clamp has a central hole with a thread cut in it to receive the screw; it
has also three pins which pass freely through three holes made in the top of the
clamp frame, the lower ends of these pins resting upon the top of the upper flask.
Upon turning the spindle by the lever or handle on its upper end the screw which
has preferably a left hand thread cut upon it is screwed upwards into the neck of
the lid and draws the frame up with it, but as the flasks are stopped by the pins
on the upper part of the flask and thereby kept from ascending with the frame
pressure is produced between the two parts of the said clamp and upon the flasks
to close the latter.
The upper part of the flask is kept from turning with the screw by providing it
with a groove or grooves to engage with a projection or projections inside the
boiler.
In another modification the clamping arrangement differs from those above
described inasmuch as the frame in which the flasks are placed is secured to the

page_text: lid or cover of the boiler so that the said lid or cover becomes the top of the clamp
to which the screw is fitted for producing pressure upon the flasks. The devices for
holding the lid in its place on the boiler are the same as above described. The
frame for holding the flasks is cast with a ring or annular portion at the top, the
interior of which is formed with a screw thread, and on the circular rim of the lid
or cover is a corresponding screw thread, and by these screw threads the frame is
firmly secured to the cover. In the centre of this circular rim of the lid is formed
a recess to receive a metal disc to be pressed upon the flasks. The said lid has
also a thread cut in its neck for the pressure screw to work through. The spindle
of the screw passes through a stuffing box having a screw cap and gland for com-
pressing the packing around the neck of the spindle and making it steam tight,
and to the top of the spindle is fitted a lever, by turning which lever the screw is
forced downwards and closes the flask or flasks placed in the frame, as above
described. When the process of moulding the celluloid, rubber, or other material
in the moulds in the flasks is completed and the pressure of steam has subsided the
boiler can be opened as first above described and the frame with the flasks therein
can be lifted out of the boiler.
According to one part of my Invention I construct the flasks for my improved
apparatus in three parts or sections, namely, a top section, which has three pins
formed or fixed on it; an intermediate. deep section formed with guide grooves
for the reception of the said pins; and a bottom section or plate with two grooves
for holding it in its place on the said intermediate section; or I modify this con-
struction by making the upper part of the flask with two pins instead of three.
The lower or deep section has the bottom cast solid or in one piece with it, and is
formed with a gap or recess in one side for the reception of a correspondingly
formed projection on the top section, and the plate with the two grooves instead of
being placed under the lower part or section is placed on the said top section and
forms the lid of the same; or both the deep and shallow sections may have a separate
cover held in its place by grooves or catches, as described.
To permit the removal of the flasks from the frame immediately after they are
taken out of the boiler so that the frame can have another set of flasks placed in it,
I employ a spring fastening to hold the two sections of each flask together until
they are quite cold.
One method of fitting this spring to the flask is as follows, that is to say, the
spring is secured to the projection on the flask in which the guide groove for the
aforesaid pin is formed. The pin has a notch made next its lower end or point in
such a position that when the flask is closed the said spring can catch into this
notch, and as there is one of these springs on each side of the flask its parts are
tightly held together till it is cold. The springs can then be released by pressing
them back and at the same time prising open the flask by inserting the blade of a
stout knife or other suitable implement between the joints of the two sections of
the flask.
Another arrangement of this spring fastening is as follows:-A notch is cut
across the guide pin and the projection on the flask in which the guide grooves are
formed. A spring is secured at one end to the flask and at each side of the same by
a screw or other means, while its other end is fitted and arranged to enter freely
into the said notch so that when the flask is closed the said spring drops into the
said notch, thereby locking the guide pin in the groove and securely holding the
parts of the flask together but permitting them to be readily separated when .
desired.
Another novel feature of my apparatus is the combined indicator and regulator,
which is constructed and arranged as follows:-To one side of the said boiler is
secured a pipe whereby the boiler is in direct communication with a part of my
apparatus which performs the combined functions of an indicator and gas regulator.
This regulator and indicator has a chamber into which opens the inlet pipe for
admitting gas to the said chamber and an outlet pipe for conducting the gas from
the said chamber to the atmospheric burner under the vulcanizer. In this chamber

page_text: or in connection therewith, and between the same and the pipe that connects it
with the said boiler (that is to say, the inlet pipe), is a spiral spring and a disc or
diaphragm of india-rubber or other suitable material. Attached to and operated by
this spring is a lever provided at its extremity with a valve or pad of india-rubber
or other like material. By the pressure of the steam in the boiler upon the said
disc or diaphragm the spiral spring is compressed and the said lever so moved that the
said valve or pad is moved to close or partially close the inlet pipe. By this operation
the supply of gas to the burner of the vulcanizer is cut off or nearly cut off. The said
valve is adjustable so that it can be set to control the supply of gas at any required
pressure and temperature. As soon as the temperature in the boiler diminishes the
pressure also diminishes and the said valve is then re-opened to permit the unim-
peded flow of gas to the burner aforesaid. In combination with the said lever I
arrange a hand for indicating on a dial the number of pounds pressure on the square
inch.
I prefer to construct this part of my apparatus as follows, that is to say, I use a
case or box resembling that of an ordinary steam gauge, and provided with a dial
enclosed by a glass face. Over the dial is placed an index finger which acts to
indicate the pressure of steam in the usual manner. In combination with this
index finger, and central with the axis thereof, I provide within the case a disc which
is attached to the gas inlet pipe and is fitted to turn with the same.
On the front
of this disc is arranged the aforesaid valve which is hinged or jointed over an aper-
ture communicating by a passage through the said disc with the said inlet pipe.
The gas escapes from the case through another pipe, and when the said valve is
open passes freely through the said case to the boiler. But on the spindle or axis
of the said index finger I fix a small arm which is arranged to come in contact with
the said valve and close or nearly close the same, as and for the purpose above
specified; or the valve instead of being jointed or hinged on the disc may_be
attached to the arm in such a position that it will cover the inlet aperture. The
said disc is also provided with a pointer and by setting this pointer to any figure
on the dial the parts of this instrument will be brought into such relation to each
other that when the steam pressure reaches a point corresponding with this finger
the arm on the index finger axis will strike the valve and thereby cut off the free
supply of gas to the heater.
It will be seen that by this arrangement of the indicator and regulator the
quantity of gas supplied to the burner of the vulcanizer is regulated by the pressure
of the steam in the boiler, and the same instrument by a hand on a dial shows the
pressure in the said boiler.
The said Invention also comprises an impression tray or cup for taking the mould
of the mouth in plaster of Paris to form the shape or pattern for the aforesaid plates.
These trays or cups are formed of perforated sheet copper or other suitable metal
not easily melted; or I make a number of small holes through the metal after the
trays or cups are stamped to the desired shape. These perforations or holes are for
the purpose of securing the plaster firmly to the tray in order that the plaster im-
pression may be properly dried by permitting the moisture in the plaster to escape
easily, as it is necessary to have the plaster impression quite dry before pouring
into the impression the metal for making the modle or mould of the mouth.

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
13th June 1879.
JOHN HUTCHENS GARTRELL, of Penzance, in the County of Cornwall.
"IM-
PROVEMENTS IN APPARATUS FOR THE MANUFACTURE OF PLATES FOR ARTIFICIAL
TEETH."
My Invention relates to improvements in apparatus for making the moulds for
pressing, moulding, and vulcanizing plates of celluloid, vulcanized india-rubber, or
similar material for artificial teeth and other purposes, and comprises devices for
regulating the flow of gas for heating the vulcanizer and indicating the pressure of
steam within it.
My Invention is illustrated in the accompanying Drawings, in which
Figure 1 is a perspective view of the said apparatus.
Figure 2 is a vertical section of a vulcanizing apparatus or boiler provided with
various devices to be used for the purposes of my Invention, as hereinafter
described.
Figure 3 is a vertical section illustrating various modifications of the said
devices.
Figure 4 is a plan or top view, and Figure 5 is a side elevation of a holder
or clamp, and illustrate the method of securing the flasks in the same, as hereinafter
described.
Figures 6, 7, 8, 9, 10, 11 illustrate my improved combined gas regulator and
pressure indicator.
Like letters indicate the same parts throughout the Drawings.
The said apparatus comprises various novel features of construction, as hereinafter
set forth, namely:-First. Providing the boiler with a peculiar clamping apparatus
to receive the flasks containing the material to be moulded and vulcanized for dental
plates. This clamping apparatus or clamp is operated by a device fitted to the lid
or cover of the latter. The said lid or cover is secured and held in place by three
levers and a screw-collar. The clamp frame is constructed of iron or other suitable
metal, and is so formed that it may be dropped into the boiler with the flasks, and
removed again when the process of moulding and vulcanizing is completed.
In Figure 2, a is the boiler, which is constructed of cast bronze or other suitable
material, and is preferably cylindrical in form; b is the clamp frame or clamping
apparatus to receive the flasks c containing the material to be moulded and vul-
canized for dental plates, and which is constructed of iron or other suitable metal,
and is secured to the lid or cover and so formed that it may be inserted into the
said boiler with the flasks c, and removed again when the process of moulding and
vulcanizing is completed. The spindle e is passed through a stuffing box f¹ in the.
lid or cover of the boiler a, the said stuffing box being fitted with a screw cap f¹
and glands which can be screwed down to compress the packing and make a
steam-tight joint around the said spindle. The lower end of the latter is connected
with the plunger f*. The latter is formed with a flange or foot which rests on the
flask, and by turning the screw spindle e the said plunger can be forced down upon
or raised from the flask.
The lid or cover f of the boiler is secured in its place by a novel device, consisting
of a set of levers g, preferably three in number, and a screw collar h. The said levers
are secured at their lower ends by steel pins g' passing through them and into lugs
or projections a¹ on the rim of the boiler a, or are otherwise fitted to turn on pivots
on the said boiler. The said levers g can be turned over to rest upon the lid f with
their ends under the said screw collar h, which is provided with handles h¹ or other
convenient means for screwing it down upon the ends of the aforesaid levers g and
exerting upon them the required pressure to hold the lid f down, suitable packing
being provided between the said lid and the surface on which it rests to ensure a

page_text: steam tight joint. In order to open the boiler the collar h is screwed back or away
from the levers g, thereby simultaneously releasing the entire set of them and leaving
them free to be turned over on their pivots g¹ clear of the lid f, which can then be
lifted off by means of the aforesaid handles h¹.
This apparatus is very advantageous in working with celluloid, as it is then neces-
sary to allow the flasks to cool down gradually under pressure; by having the clamp
separate from the boiler, in the manner described, the said clamp can be removed
with the flasks in it and placed aside to cool down altogether, while another clamp
can be placed in the boiler and another set of flasks worked without delay. This
object is greatly facilitated by constructing the spindle and screw in the manner
hereinafter described.
In some instances I modify the construction of my improved apparatus, as shewn
in Figures 3, 4, and 5, in such a manner that the clamp 6 is so operated by the spindle e
and screw d that the flasks c within the same are closed by the said clamp being
drawn upwards instead of being pressed downwards, as in the apparatus shewn in
Figure 2. The advantage gained by this modified arrangement is that I draw away
the flasks from the bottom of the boiler and so prevent an undue heating of the
lower flask, which being the nearest to the part of the boiler receiving the heat of
the atmospheric burner is subjected to greater heat than the upper flask. This
purpose is effected by making the clamp b in two parts b', 62, namely, the frame
and the top part, and which are operated to close the flasks in the following
manner-The frame b¹ in which the flasks are placed to be closed for moulding the
celluloid or rubber plates is supported by the screw d by means of the collar d*
formed upon the lower end of the same, and free to turn in a recess formed for the
same in the under side of the upper part of the said frame. The upper part 62 of
the said clamp has a central hole with a thread cut in it to receive the screw d.
It is also provided with pins bs (preferably three in number) which pass freely
through holes b in the top of the clamp frame 3', the lower ends of the said pins
resting upon the top of the upper flask. The screw d in this modification of my
Invention is provided with a square, hexagonal, or other shaped opening in its upper
end, into which the similarly shaped end of the spindle e fits, and by turning the
said spindle by a lever or handle placed upon its upper end the screw d, which has
preferably a left hand thread cut upon it, is screwed upwards into the neck of the
lid f and draws the frame b¹ up with it, but as the flasks c are stopped by the pins b³
on the upper part 6 of the said flask and thereby kept from ascending with the
frame, pressure is produced between the two parts 61, 62, of the said clamp, and upon
the flasks c to close the latter.
The upper part 62 of the said clamp is kept from turning with the screw d by
providing it with a groove or grooves 6 to engage with a projection or projections
inside the boiler.
In another modification the clamping arrangement differs from those above
described, inasmuch as the frame on which the flasks are placed is secured to the
lid or cover of the boiler, so that the said lid or cover becomes the top of the clamp
to which the screw is fitted for producing pressure upon the flasks. The devices
for holding the lid in its place on the boiler are the same as above described. The
frame for holding the flasks is cast with a ring or annular portion at the top, the
interior of which is formed with a screw-thread, and on the circular rim of the lid
or cover is a corresponding screw-thread, and by these screw threads the frame is
firmly secured to the cover. In the centre of this circular rim of the lid is formed
a recess to receive a metal plunger to be pressed upon the flasks. The said plunger
has a thread cut in it for the pressure screw to work through. The spindle of the
screw passes through a stuffing box having a screw cap and gland for compressing
the packing around the neck of the spindle and making it steam-tight, and to the
top of the spindle is fitted a lever, by turning which lever the screw is caused to
revolve, and forces downwards and closes the flask or flasks placed in the frame, as
above described. When the process of moulding the celluloid, rubber, or other
material in the moulds in the flasks is completed, and the pressure of steam has

page_text: subsided, the boiler can be opened as first above described, and the frame with the
flasks therein can be lifted out of the boiler.
Another novel feature of my apparatus is the combined indicator and regulator.
I prefer to construct this part of my apparatus as shewn in Figures 6, 7, 8, 9,
10, 11. Figures 6 and 7 are front and rear elevations; Figures 8 and 9 are similar
elevations, with the parts in different positions; Figure. 10 is a transverse section
on the line x, x, Figure 7; Figure 11 is a side view. I use a case or box i resembling
that of an ordinary steam gauge, and provided with a dial * enclosed by a glass
face. Over the dial is placed an index finger j, which acts to indicate the pressure
of steam in the usual manner. In combination with this index finger and central
with the axis thereof I provide at the back of the case a disc k, which has a neck
or tube k*, to which is connected the gas inlet pipe l. Within this tube or neck,
which forms the valve chamber, is arranged the valve 1, this valve is arranged near
the mouth of the outlet pipe m, which extends through the side of the valve
chamber. The gas enters the valve chamber through the inlet pipe l, and when the
said valve is open, as shewn at Figure 7, the gas passes freely through the said
chamber and pipe m to the boiler. But the said valve is carried on the spindle or
axis of the said index finger, or is arranged in combination with a small arm on
the said spindle, so that the said spindle or arm will move the aforesaid valve l
and close or nearly close the same when the desired pressure in the boiler is reached.
The disc is also provided with a pointer o, and the parts above described are so
arranged relatively to each other that when this pointer is set to any figure on the
dial *, and the steam pressure reaches a degree corresponding with this figure, that
is to say, when the position of the finger coincides with that of the pointer, the
valve will close the pipe m, and thereby cut off the free supply of gas to the
heater.
It will be seen that by this arrangement of the indicator and regulator the
quantity of gas supplied to the burner of the vulcanizer is regulated by the pressure
and according to the desired pressure of the steam in the boiler, and the same
instrument by hand on a dial shews the pressure in the said boiler.
Having thus fully described my said improvements, and shown how the same
may be conveniently and advantageously carried into practice, I wish it understood
that I am aware of there having been already in use an apparatus for manufacturing
dental plates, a clamping device, which has a frame for holding the flasks separate
from the boiler, so that the said frame, with the flasks securely held in it, can be
placed in or removed from the boiler; I therefore do not claim this device broadly
or irrespective of the novel features herein described, whereby I dispense with the
inconvenient and complicated arrangement of bevil wheels and other devices for
permitting the adjustment of the said clamp, as described in the Specification of
Letters Patent dated 21st August, A.D. 1878, No. 3300, but I claim,―
First. A clamp or holding device which has a frame or stirrup separate or detached
from the boiler or vulcanizer, and which is adapted to hold the flask or flasks
therein, and which is adjusted by means of a spindle or rod passed through the
cover of the boiler, and connected directly with the clamp-screw without any inter-
mediate gearing in such a manner that when turned it will turn the said screw and
thereby operate the said clamp, but which spindle is not attached to or formed on
the said screw, so that the clamp may be readily removed from the boiler, as and
for the purposes specified.
Second. The modification of the said clamping apparatus, wherein the frame or
strirrup is attached to the cover of the boiler, as and for the purposes specified.
Third. In combination with the said boiler and the cover the pivotted levers and
screw collar arranged and operating as and for the purpose specified.
Fourth. The modification of my Invention, whereby the clamp or clamping device
illustrated in Figures 3, 4, 5, and as above described, is closed by drawing the flasks
upward instead of pressing them downward, as and for the purpose specified.
Fifth. The apparatus or means whereby I provide for the regulation of the
quantity of gas supplied to the burner by and according to the pressure of steam in

page_text: the boiler, as shown in and described with reference to Figures 6. to 11 of the
Drawings, or any modifications of a combined gas regulator or regulating valve and
steam pressure gauge or indicator, operating as and for the purposes' specified.
In witness whereof, I, the said John Hutchens Gartrell, have hereunto set my
hand and seal, this Eleventh day of June, in the year of our Lord One 5
thousand eight hundred and seventy nine.
JOHN H. GARTRELL. (L.S.)