Improvements in the Method of and Apparatus for Constructing Plates for Dental Vulcanizing Purposes.
Year: 1895

page_text: PROVISIONAL SPECIFICATION.
Improvements in the Method of and Apparatus for Constructing
Plates for Dental Vulcanizing Purposes.
I, CHARLES DONALD GRUNDY, of Branch House, Batley, in the County of
York, Dental Surgeon, do hereby declare the nature of this invention to be as
follows:-
The object of my invention is to construct an apparatus by which the plates
required for the formation of vulcanite artificial roofs for dental purposes may be
constructed in a simpler and more expeditious manner than hitherto, and in such a
way, any number of plates each having the varying minute indentations and other
irregularities of the roof of a person's mouth, may be reproduced, and all exactly
correspond, without having to beat the plate as hitherto, in order to make it fit the
cast of the said roof.
In carrying out my invention, I form a liquid press having a receiver covered
with a flexible diaphragm tight around its edge, and below the same is a moveable
cup, which may be held in contact with the edge of the said diaphragm by a cam
or other suitable means.
The negative mould of the roof is constructed as hitherto, and from the negative,
another mould is cast and inserted in the before mentioned cup or other suitable
support.
Upon the last mentioned mould placed a soft metallic plate, and the cup or
other support brought into tight contact with the edge of the before mentioned
flexible diaphragm, on the opposite side of which, liquid pressure is applied by
means of a pump, which causes the diaphragm to expand and force the soft metallic
plate into the cavity of the mould in close contact with the same, with such gradual
but effective force, that, all the irregularities and indentations in the contour of the
surface of the mould are minutely reproduced, without having to beat or otherwise
manipulate the plate as hitherto. On the release of the pressure by the opening
of a valve, the liquid flows back into a small reservoir connected with the
apparatus.
By the use of my apparatus, any number of plates may be made from the same
mould, and all correspond in the irregularities or indentations with the roof of the
mouth, so that any thickness of plates may be built up for the formation of
vulcanized roofs, and top and bottom plates for polishing purposes both having
exactly the same configuration.
Dated this 21st day of June 1895.
JOHN WAUGH,
Agent.

page_text: Improvements in the Method of and Apparatus for Constructing
Plates for Dental Vulcanizing Purposes.
I, CHARLES DONALD GRUNDY, of Branch House, Batley, in the County of
York, Dental Surgeon, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement :--
The object of my invention is to construct apparatus, by which an impression of
a person's mouth, whether of plaster or of composition, may be lined with a thin
plate of metal, from which a model may be cast which shall have a bright metallic
surface upon which to vulcanize and by which the contour trial base plates and
polishing plates may be constructed in a more simple and expeditious manner than
hitherto, and in such a way that the various minute indentations and other
irregularities of the roof of a person's mouth may be reproduced.
:
In describing my invention in detail reference is made to the accompanying sheet
of drawings in which :-
Fig. 1. represents a section of complete apparatus.
Fig. 2. plan of complete apparatus.
Similar letters indicate similar parts.
A liquid press indicated by the letter P is fixed above chamber C. The bottom
of the chamber C is formed of an indiarubber diaphragm I. Bracket B is capable
of turning or swinging upon pillar S, and also may be raised or lowered by means of
cam L, which is operated by lever M. A movable metal cup K with a loose
bottom O rests upon bracket B for the purpose as bereinafter described.
When
bracket B is in position shewn on drawings, cup K is exactly centred with
chamber C, and is pressed into contact with rubber diaphragm, and locked there
until released by a movement of cam L.
It will be readily understood that to line an impression of a person's mouth with
a plate or film of metal, the impression being first constructed as hitherto, cup K
is nearly filled with soft plaster, and the impression still in the tray in which it was
taken is pressed into it. Cup K is provided with a slot thro' which the handle of
the tray may be passed. When the plaster is set and trimmed a sheet of the metal
cut to a suitable size is placed on the impression. The cup K is placed in position
on bracket B, which may then be brought round into position shewn on drawing.
Cup K may then be pressed into contact with diaphragm I in the manner as herein
before described.
Press P is now operated, and the liquid filling chamber C exerts great pressure
on the top side of the rubber diaphragm aud causes the latter to press down the
soft metal into close contact with the impression, thus lining it with a film of
bright metal.
Before removing impression from cup K, plaster must be run in to the lined
impression; when this is set the whole may be removed from cup K by a sharp
blow upon the movable bottom O. The original impression and superfluous plaster
may now be broken away and a model of the mouth is left covered with bright
metal.
Trial and base plates may be made by taking an impression of the covered
model in composition. Cup K is then filled with plaster, and the composition
impression is pressed into it, thus a model is obtained similar to the first but not
covered with inetal. A sufficient thickness of the thin metal plates are now pressed
on to the model in the manner as herein before described, thus forming a trial and
base plate.
The base plate is mounted on covered model in the same manner as hitherto, and

page_text: an impression of this being taken plates of metal are pressed on to the latter
impression, and a polishing plate is obtained.
The vulcanizing process taking place between the polishing plate and the metal
covered model, a polish is obtained without subsequent retouching hitherto
unattainable. The vulcanite is of the same thickness throughout, and the various
minute indentations and other irregularities of a person's mouth are reproduced.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. The general combination of the parts forming the complete apparatus,
arranged substantially in the manner and for the purpose as herein before set forth.
2. The combination of liquid press and rubber diaphragm, arranged substantially
in the manner and for the purpose as hereinbefore set forth.
3. The combination of sheets of thin metal and plaster or composition models or
impressions, arranged substantially in the manner and for the purpose as herein-
before set forth.
Dated this 19th day of March 1896.
CHARLES DONALD GRUNDY.