Dental Impression Tray Moulding and Casting Box.
Year: 1899

page_text: Date of Application, 4th Feb.,
1899
Complete Specification Left, 30th Oct., 1899-Accepted, 2nd Dec.,
1393
PROVISIONAL SPECIFICATION.
Dental Impression Tray Moulding and Casting Box.
ARTHUR LOFTUS BETHELL, 16, St. Paul's Road, St. Leonards-on-Sea, Sussex,
Dental Mechanic, do hereby declare the nature of this invention to be as
follows:
This dental impression tray moulding and casting box is constructed of brass
of of an inch in thickness, it is made in four detachable parts, these parts
when put together form a horse-shoe-shaped receptacle, or box. Its dimen-
sions are height 5½ inches breadth at widest part 4 inches greatest length
6 inches. This moulding and casting box is divided horizontally into equal
halves, that is the top half, and the lower half of this receptacle. To three of
the exterior sides of the lower half of box are attached three vertical slots,
or grooves, one groove to each of the three sides. To the top half of the moulding
and casting box, and to three of the exterior sides, (as per lower half of box)
are affixed three vertical pins, these pins are adjusted, and fixed in position,
so that they exactly slide down each into its respective groove in the lower
half of the moulding and casting box, so that the two halves of the box come
together in a true, and guidable position as required. To the top half of this
moulding and casting box is a removable lid, or cover, with flanges on its
interior side, which is kept securely in its true position, when in use, by two
swivel clamps, working laterally, and on pins attached to the lower half of the
box, these are also on the exterior, and these two swivel clamps are fixed the
one to the right side, and the other to the left side of the box, as from a front
view of the same, each in the centre of its respective side, upon the exterior
of the lower half of the box. The remote end of these swivel clamps from
their pin adjustment spring upon by their lateral movement, two flat horizontal
projections on the lid, or cover and thus not only do they hold the lid to its
position but the whole combination of the box is held together as it is required
during the casting of the especial dental impression tray. When the tray is
being moulded, the swivel clamps are released, and working laterally they drop
down out of the way each swivel clamp against its respective side of the lower
half of the moulding and casting box. In the front of the box, and in the centre
is left a square hole, one inch, by, one inch square this hole embraces the two
halves of the box, the half of the hole in the top half of the box, and the half
of the hole, in the lower half of the box to the right and left of this opening
and affixed to the lower half of the box on the exterior are two grooves, in these
grooves a sliding shutter is placed during the moulding of the tray it slides
down vertically to its position, it is 7 inches in length by 1 inches in breadth
its length when in position, admits when required to do so, its easy removal,
as it is an inch higher than the height of the moulding and casting box. This
slide is in position during the moulding of the tray, and removed during the
casting of the impression tray. This moulding and casting box, during the
process of casting the tray is inverted, the side upon which the square opening

page_text: is being uppermost the side of the box directly opposite to this side becomes
for the time the base of the box. To give this side of the moulding and casting
box, a firm and steady base, four supports, or legs are attached, the two legs
to the one half of the box, and two legs to the other half of the box. In the
interior of this moulding and casting box and affixed to the base of the square
opening is a horizontal tongue" shaped shelf one inch wide by half an inch
long.
This dental impression tray moulding and casting box, need not necessarily
be made of brass but can be constructed of gun metal, delta metal, cast, or
forged iron, and the like.
During the moulding of the especial trays this invention will contain
moulding sand, and the like wood, bee's wax, French chalk, or composition.
During the casting of the dental impression trays this invention will contain
moulding sand, and the like, French chalk, pewter, Brittania metal, block tin
or the like.
Dated this 3rd day of February 1899.
Dental Impression Tray Moulding and Casting Box.
I, ARTHUR LOFTUS BETHELL, of 16, St. Paul's Road, St. Leonards-on-Sea,
Sussex, Dental Mechanic, 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:-
My invention has for its object the novel construction of moulding, and
casting boxes for use in making dental impression trays, whereby greater
facility is attained for making such trays, and at the same time such boxes,
being for the use of dentists, or those persons skilled in the art, or profession,
of dentistry.
The boxes are constructed of brass, or other suitable material such as gun-
metal, delta metal, cast or forged iron, wood and the like. With the help of
the accompanying sheet of drawings I will proceed to explain the various
parts in the construction of the same.
Figure 1, is a perspective view of the top half of the box, and Figure 2,
the lower or bottom half of the box. Figure 3, is a transverse section on
line 1,2, of the upper half of the interior of the box. Figure 4, is a view of a
detail hereafter to be described. Figure 5, is a view of another detail. The
box is composed of four detachable pieces, A being the top portion, B the
bottom portion, C a lid, or cover, for the top portion A, and 1 being a shutter
or slide. These four detachable parts when placed together form preferably a
horse-shoe shaped box, and enclosed upon all sides.
To three of the exterior sides of the lower half of the box B, are attached
three vertical slots, or grooves, E, F, and G. Upon the top half A of the box
are attached legs, or pins, H, I, and J, which are in a relative position to the
slots, or grooves, E, F, and G, on the lower half of the box, so that in placing
the two halves together they will slide in such grooves, thus keeping the two
halves in a true position as required. The top half A is provided with a
movable lid C, or cover, with flanges upon its interior sides, this lid is kept in
its true position, and firmly secured when in use by two swivel clamps K,
and L, working laterally on pins attached to the lower half of the box B, on
either exterior side of this half of the box. These swivel clamps K, and L,

page_text: have notches M, and N near the ends which engage or slide into corresponding
notches O, and P, in a cross-piece secured on the lid C of the top part A, and
so holds the whole combination of the box tightly together as it is required
to be during the process of casting the dental impression tray. When the
tray is being moulded, the swivel clamps are released, and working laterally
upon their pin adjustment drop down out of the way each swivel clamp against
its respective side of the lower half of the box and towards the front of this
half of the box,
In the front of the box, I form a square hole R in the lower half B, the
metal, (or constructive material) in front being cut part way down, and turned
or bent inwards forming a tongue-shaped shelf S as shown in drawing, and in
working out this my invention prefer this method. Upon either side of the
square opening RI form grooves T, and U, one groove to each side in which
a shutter or slide 1) slides, and so closes the orifice during the moulding of the
tray, being removed, and exposing the orifice during the actual running, or
pouring of the liquified metal into the mould after the removal of handle W,
block X, and the wax, or composition tray as moulded upon plaster of Paris
models of the mouth. During the process of casting, or running the metal,
the box is inverted, that is, placed upon the legs V of which there are four,
the two legs to the top half of the box A, and two legs to the bottom half of
the box B, the square hole, or orifice, being uppermost, thus ensuring a good,
and sound casting by the law of gravitation. We will suppose the wax (or
composition) pattern of tray to be imbedded in the lower half of the box B,
the block X (see Figure 6,) having been previously cemented to pattern upon
the side immediately opposite to the orifice R. The block X has two small
holes drilled in its face, the handle W having two pins projecting from its
thinner extremity, or end, which coincide with, and fit exactly into the drilled
holes in the block X, during the taking of the impression of the pattern in
the mould, the handle W is fixed to the small block X, the pins fitting into
their respective holes, handle W being also embedded its whole length, and
its thicker end resting upon the shelf S ready for withdrawal by pliers, by the
holes drilled in the face of the handle W, and made for the reception of the
points, or grasping parts of this instrument. The top half of the box is now
placed in position, the legs or pins H, I, and J sliding home into their respec-
tive slots, or grooves E, F, and G, the movable top lid, or cover C, is removed
thus enabling the top half of the pattern being taken by ramming down the
moulding sand (and the like) from the top thus getting a correct impression.
When mould is complete the handle W is removed, or extracted with pliers
through the hole R, being easily withdrawn on account of it being well tapered
in thickness, and width, when removed this handle leaves a tunnelled space
down which the molten metal is poured, after the pattern of tray has been
removed from the moulding sand or the like. To add strength and rigidity
to the top portion of the box, and to assist in retaining the sand, or the like
when moulded, I place a round wire rod, or piece Y as shown in the section
Figure 3, round the inside circumference about midway of the depth of the
top half A. The lid, or cover, C, is strengthened by a longitudinal piece Z,
and carries a knob to facilitate its removal when required to do so.
It will thus be seen that I construct a moulding, and casting box having
great facilities for rapid, and efficient moulding, and casting, and giving
great exactness in such moulding, and casting as specially required in the
formation of dental impression trays (both of the special," and ordinary"
kind).
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is

page_text: impression trays composed of, and made in the various parts as herein before
described, and shown upon the accompanying drawings.
2nd. A novel moulding, and casting box being made in four detachable parts
of the peculiar construction as herein before described, and shown upon the
accompanying drawings.
3rd. A novel moulding, and casting box having a suitable orifice, as, and
for the purpose herein before set forth, and shown upon the accompanying
drawings.
4th. A handle, and block, and the means for guiding such handle, and the
use of such block, as for the purpose herein before set forth, and shown upon
the accompanying drawings.
5th. The special process as described in the foregoing description, of, and
for the use of this dental impression tray moulding, and casting box.
Dated this 28th day of October 1899.
ARTHUR LOFTUS BETHELL.