IMPROVEMENTS IN OR APPLICABLE TO MOULDING OR VULCANIZING FLASKS FOR DENTAL PURPOSES, AND IN MOULDING DENTAL PLATES
Year: 1881

page_text: LETTERS PATENT to John Smalley Campbell, of New York, United States
of America, for an Invention of "IMPROVEMENTS IN OR APPLICABLE TO
MOULDING OR VULCANIZING FLASKS FOR DENTAL PURPOSES, AND IN
MOULDING DENTAL PLATES."
PROVISIONAL SPECIFICATION left by the said John Smalley Campbell at
the Office of the Commissioners of Patents on the 15th August 1881.
JOHN SMALLEY CAMPBELL, of New York, United States of America. "IMPROVE-
MENTS IN OR APPLICABLE TO MOULDING OR VULCANIZING FLASKS FOR DENTAL
PURPOSES, AND IN MOULDING DENTAL PLATES."
This Invention relates to certain improvements in or applicable to so-called dental
flasks for moulding or vulcanizing dental plates.
The improvements consist in provisions for closing a dental flask obliquely, and
in oblique guides for that purpose secured to one part of the flask and operating
against the opposite part as the two portions of the flask approach each other in
closing; it also consists in a combined oblique or inclined and a perpendicular
guide, which oblique guides consist preferably of movable studs or pins provided
with a head and a partially screwed and partially plain neck terminating in a point
whose termination is out of the axial line of said studs or pins by reason of the
pointing of the pin or stud having been made from one side only of the pin, thus
providing the inclined face or guide. The said inclined guides may be more or less
imperfectly obtained by bending or tipping the ordinary fixed pins to one side, or
by fixed inclined guides or slots and corresponding ears or guide pieces on the two
parts of the flask, but by the inclined pointed guide pins being capable of adjust-
ment the inclined approach of the top portion of the flask can be ensured from any
required direction, and by the final plain perpendicular portion of the pin the final
closing will be directly perpendicular.
Holes are provided through the pins for reception of holding pins for keeping
the flask closed upon its contents whilst cooling, and a yoke piece or eye is also
employed to span two projecting studs on the parts of the flask to assist in holding
same together.

page_text: The top and bottom portions of a flask are provided with covers on the top, one
only with a cover, and the covers are made to lock back and front by corresponding
studs and holes in projecting ears on the flask and covers, or by a stud and
corresponding hole and a catch piece.
These improvements provide for the effectual carrying out of the improvements 5
in moulding dental plates, which consist in the closing of the top portion of the
flask obliquely in relation to the lower portion in order to effect the moulding of
and operating upon undercut or irregular models, and obviate the necessity of
fitting the blanks in celluloid cases, and the reopening of the flask in extracting
the moulded specimen is greatly facilitated. In an ordinary bolted vulcanizing 1
fiask these. improvements of inclined guides and locking covers may be used in
combination.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Smalley Campbell in the Great Seal Patent Office on the
15th February 1882.
JOHN SMALLEY CAMPBELL, of New York, United States of America. "IMPROVE-
MENTS IN OR APPLICABLE TO MOULDING OR VULCANIZING FLASKS FOR DENTAL
PURPOSES, AND IN MOULDING DENTAL PLATES."
This Invention relates to certain improvements in or applicable to so called dental
flasks for moulding or vulcanizing dental plates.
These improvements consist in provisions for closing a dental flask obliquely,
and in oblique guides for that purpose secured to one part of the flask and
operating against the opposite part as the two portions of the flask approach each
other in closing; it also consists in combined oblique or inclined and perpendicular
guides, which oblique guides consist preferably of movable studs or pins provided
with a head and a partially screwed and partially plain neck terminating in a point,
which point of termination is out of the axial line of said studs or pins by reason
of the pointing of the pin or stud having been made from one side only of the pin,
thus providing the inclined face or guide. The said inclined guides may be more
or less imperfectly obtained by bending or tapering the ordinary fixed pins to one
side, or by fixed inclined guides or slots and corresponding ears or guide pieces on
the two parts of the flask, but by the inclined pointed guide pins being capable of
adjustment around the inclined approach of the top portion of the flask can be
ensured from any required direction, and by the final plane perpendicular portion
of the pin the final closing will be directly perpendicular.
Holes are provided through the pins for reception of holding pins for keeping
the flask closed upon its contents whilst cooling, and a yoke piece or eye is also
employed to span two projecting studs on the parts of the flask to assist holding
same together. The top and bottom portions of a flask are provided with covers,
or the top one only with a cover, and these covers are made to lock back and front
by corresponding studs and holes in projecting ears on the flask and cover, or by a
stud and corresponding hole and a catch piece.
These improvements provide for the effectual carrying out of the improvements
in moulding dental plates, which consist in the closing of the top portion of the
flask obliquely in relation to the lower portion in order to effect the moulding of
and operating upon undercut or irregular models, and obviate the necessity of
filling the blanks in celluloid cases, and the reopening of the flask in extracting the
moulded specimen is greatly facilitated.
In an ordinary bolted vulcanizing flask these improvements of inclined guides
and locking covers may be used in combination with the bolts, thereby obtaining a
firmer locking of the parts together.
"
In the accompanying Drawings, Fig. 1 is a plan of the upper half of the flask or
'cope" as it is variously termed.
Fig. 2 is a side view of a flask provided with the perpendicular guide as
ordinarily made, the entire right hand side of the flask being shown in section to
exhibit the mould and the celluloid or rubber "blank."
Fig. 3 is a side elevation of my improved flask with the adjustable incline
guides, the top portion of the guide pin being tapered or inclined on one side to
within a short distance of the bottom thereof, and then made perpendicular, by
which means the final pressure is uniformly applied.
Figs. 4 and 4 are views of the adjustable tapered guide pin shown in Fig. 3;
and Fig. 4b shews the yoke piece for aiding the locking of the parts of the Hask

page_text: when closed; and Figs. 4° and 4d are views of guides of other modes of con-
struction.
Figs. 5 and 6 are views of two different constructions of the improved flask, in
which the several portions are shown in position apart before being put together,
Fig. 6 showing the ordinary bolted flask with my improvements combined; Figs. 7
and 8 are views of the flask shown in Figs. 5 and 6 closed.
In flasks provided with the ordinary guide pins shown in Fig. 2, the parts of
the flask lettered A, A¹, in the Drawings are necessarily limited to a movement
perpendicular to their parting or dividing line l. Such a movement is desirable in
many cases, but in packing a plate upon an undercut bed or mould, such as is
shown at B in Fig. 2, great difficulty arises in forcing the plate (indicated at P)
to its proper position between the two parts of the mould shown in section at B
and C.
Much difficulty is also experienced in separating the parts B and C by a
perpendicular movement to remove the wax model when the bed is undercut, as
at e on the one hand, and the opposed corner, as at d, is hooked under by the
conformation of the model, for in such cases the natural movement of the parts
separated would be parallel with the undercut line at e. As the perpendicular
guides usually employed do not allow of such a movement, the plaster above the
undercut part is frequently broken and the mould spoiled. The perpendicular guides
also prevent the upper half of the mould when formed with a hooked corner, as
at d, from bearing equally upon the blank plate P and pressing it into uniform
contact with all the parts of the bed B. Upon the contrary, the corner & bears
forcibly upon the blank at its front side and pushes it backward as the mould
closes, in consequence of which the front part of the mould is imperfectly supplied
with material, as is necessary for a perfect plate, whilst the rear part is overcrowded
with an excessive amount thereof.
My Invention obviates these difficulties in operating upon undercut models by
providing the flask with the inclined guides in place of the perpendicular ones
heretofore employed, the inclination of the guide enabling the operator to execute
all ordinary work with equal ease, while it affords special facility for treating
unusual cases.
My improved flask is also especially adapted for the production of rubber plates
inlaid with celluloid upon the front, as in such work a movement of the cover C
and the blank P toward the undercut face e affords a greater pressure at that
particular point and secures a closer union between its two substances forming the
plate.
It is obvious that an inclined guide could be obtained by merely tipping the
guide pins g toward the front of the flask and inclining the lugs h at a similar
angle, but as it is desirable to have the final movement of the cover A perpendicular
to the bottom A¹, it is preferable to have a guide capable of producing or afford
both such movements, and the pins E are designed to secure an oblique movement
of the cover, and that from any predetermined direction until the flask is nearly
closed, and then to permit the action of a perpendicular guide by the aid of which
the final pressure is more uniformily distributed than if the cover moved to its
final position in an oblique direction.
In Figs. 1 and 3, A. is the cope of the flask; B, the bed; C is the cover of the
cope removably secured thereto by the pierced lugs D and the studs d; C¹ is the
removable base of the bed which is likewise provided with lugs and secured to the
bed B in a similar manner.
E is the improved adjustable tapered guide pin which is made fixed or adjustable
at pleasure, so that its control over the flask is removed when the wax model or
plate is completed, and the flask may be opened at any inclination or in any
direction that is desired.
In Figs. 4 and 42, this guide pin E is shown apart from the flask by which it
will readily be seen that it is provided with a screw thread vat one end for the

page_text: purpose of securing it into the lugs b formed upon the flask, and with a notched
head C for turning it round as required. The said guide pin is also provided
about half way of its length with a hole for reception of a pin, by which means the
top part of the flask is secured in position whilst the contents of the flask may be
cooled down or otherwise. The upper and lower portions of the flask are also
provided with studs and locked together by means of a yoke piece G.
These improvements may also be used in combination with the ordinary bolted
flasks, thereby obtaining a better working of the ordinary flask than has hitherto.
been the case. By this construction the pin can be removed from its place when
the wax model is to be inspected and the mould opened without danger to the
interlocking parts of the plaster casts.
It is evident that the guide may be constructed in other manners, as at d, e,
in Fig. 40, where d is a simple pin projected from the side of the cope, and e is a
forked plate secured to the bed B by two screws inserted in holes 8, 8; such a device
will guide the cope perpendicularly when desired, and may be removed by taking
out the screws from the holes by a screw driver. When made as indicated by the
dotted lines, an inclined guide will be formed for the purpose before explained.
In Fig. 4d is shown a round pin provided with a foot f having two holes t, t, for
the insertion of screws to secure it to the bed. By employing such a pin in
conjunction with the lug and making the guide hole in the latter of conical shape,
the guide may be loosened to operate in the required manner by merely removing
one of the screws from the foot of each guide. The pin would then be at liberty
to take any required inclination automatically as the parts of the flask were
separated, provided no side movement of the cope was required.
In Figs. 5 and 7 is shown this improved flask in open and closed position, and
showing the guide pins in position.
Referring to Figs. 6 and 8, this improved guide pin is shown used in connection
with an ordinary bolted flask.
As shown in Figs. 3, 5, 6, 7, 8, the top and bottom portions of the flask are
provided with covers, or the top one only with a cover, and these covers are made
to lock at the back and front by corresponding studs and holes in projecting ears
on the flask and cover.
From the above description it will be seen that the essential feature in my
Invention consists in providing the flask with a guide of such character that the
flask can be closed and opened in a different direction or at an angle other than
a right angle from or to the parting or dividing line that is in a varying direction,
and the moulding of the plates under such conditions and thereby.
Having now described the nature and particulars of my said Invention, and
shown how the same may be carried into effect, I claim,
Firstly. In combination with a two or more part dental flask, an inclined guide
or guides, secured to one part of the flask and operating to move the other part
obliquely to its final position when closing, as and for the purpose substantially as
herein set forth and described in reference to the accompanying Drawings.
Secondly. In combination with a dental flask a guide or guides, part whereof is
inclined and part perpendicular, whether said guides be adjustable or not for
direction operating to direct the flask portions when closing, as and for the
purpose specified.
Thirdly. A dental flask having a guide or guides constructed to direct the
movement of the parts when closing and adapted to be removed or loosened for
opening the flask when required, as and for the purpose specified and shown by
the respective Figures of the Drawings.
Fourthly. In combination with the flask A, B, provided with, the lugs b, the
removable guide pin E provided with screw thread at one end, and operating
with the lugs to guide the cope, substantially as and for the purpose herein set
forth and as shown by the accompanying Drawings.
Fifthly. In combination with the dental flasks as herein described, the removable

page_text: top or bottom plates with pin and hole fastenings for sliding the said top or
bottom plate on into position, and retaining the same from vertical displacement
as herein set forth.
In witness whereof, I, the said John Smalley Campbell, have hereunto
set my hand and seal, this Fourteenth day of February, in the year of our
Lord One thousand eight hundred and eighty two.
In the presence of
WALTER A. BARLOW,
Patent Agent & Engineer,
6, St. Paul's Churchyard,
London, E.C.
-
JOHN S. CAMPBELL. (LS.)