Improvements in the Art of Forming Articles or Casts in Resinous or Fusible Cements or Compounds.
Year: 1888

page_text: Date of Application, 22nd Mar., 1888
Specification Accepted, 4th May, 1888
COMPLETE SPECIFICATION.
Improvements in the Art of Forming Articles or Casts in Resinous
or Fusible Cements or Compounds.
I, CHARLES MICHAEL HIGGINS, of the City of Brooklyn in the County of Kings and
State of New York, Manufacturer, do hereby declare the nature of my invention for
IMPROVEMENTS IN THE ART OF FORMING ARTICLES OR CASTS IN RESINOUS OR FUSIBLE
CEMENTS OR COMPOUNDS 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 make or cast various small articles from a fusible
resinous composition in a rapid simple manner without requiring complicated or
expensive machinery to press the composition into molds, and without requiring the
molds to be oiled or lubricated. Heretofore such casting has generally been done by
preparing the resinous compound in a plastic state in sheets or masses, which is then
forced by powerful pressure into molds to produce the articles of the desired shapes.
The molds and presses for this system are necessarily expensive, and furthermore a fin
or seam is usually left on the article or casting at the joints of the mold, which has to
be subsequently finished off.
Now the object of my invention is to enable the articles to be cast from a liquid or
fused resinous compound poured hot directly into the molds, thereby dispensing with
pressure and the machinery therefor, and at the same time enabling dry molds to be
used, obviating the necessity of oiling and yet prevent the possibility of the castings
adhering to the molds, and at the same time producing a fine surface finish or polish on
the castings. To this end I have discovered that if the molds are made of massive
bodies of metal, or composed of other material which is a good conductor or absorber
of heat, and made of sufficient mass, that the resinous compound may be poured hot
and liquid into the same, and will produce a perfect casting which will follow every
intricacy of the mold, and will soon solidify therein, and may be freely removed when
solidified without any danger of sticking. A series of these molds are used successively,
the casting being removed from the first of the series after the last of the series has
been filled, the molds being thus emptied and filled in rotation, a sufficient number of
molds being used to allow cach mold to cool sufficiently after each casting so as to
prevent any continued accumulation of heat therein. I have found that if the molds
were to get very hot the castings would adhere firmly thereto and could not be removed,
but if the molds are not allowed to get more than well warmed, much below the
melting point of the compound, the casting may be performed therein in a perfect
manner without any sticking, for an unlimited time. It will therefore be seen that by

page_text: having the molds made of massive blocks of metal or other good conductor of heat,
that the heat is drawn away from the casting so fast as to prevent the surface of the
mold rising to a temperature which would cause adhesion to the casting, and it will be
further seen that by using a series of molds in succession, the first one will cool down
sufficiently by the time it requires to be used over again as to prevent any accumu-
lation of heat which would cause sticking, so that the casting can thus be
performed continuously in a very rapid, simple and inexpensive manner.
My invention therefore consists mainly in the system above outlined, and also in
the special manner of making and using the molds, as hereinafter fully set forth.
My improved system of casting has been more especially designed for making
bottle-caps and stoppers, bottle brushes, and various other small articles, but it of
course may be applied to a great variety of articles, but in the drawing I have
illustrated the manufacture of bottle-caps and stoppers.
In the drawings Fig. 1 presents a section of the two parts of a mold made according
to my system, and adapted for the casting of mucilage or, bottle-brushes. Fig. 2 is
a similar section illustrating the operation of casting. Fig. 3 is a section of both
parts of the molds put together and filled, showing the casting or brush in the mold
complete. Fig. 4 gives a perspective view and section of the finished casting or
brush removed from the mold. Fig. 5 gives a perspective view of a bottle-stopper
made according to my system and Fig. 6 represents a sectional view of the
stopper and of the mold for making the same, showing the mode of forming the
stopper. Fig. is a section of a capped mold for more accurately forming the
same kind of stopper. Fig. 8 is a section of a modified form of mold.
Referring to Figs. 1, 2 and 3, a indicates the body of the mold, which is a
solid or massive block of metal, having a cavity formed therein, which is of the
same shape as the article desired to be cast therein. The article is, in this case,
a capped bottle-brush, as seen in Fig. 4. such as used for ordinary mucilage
bottles and similar purposes. This brush has the usual bristles C and the
tubular tin or metal stem .d, and the tin or metal cap g, but it is also formed
with a novel ornamental handle e and cap f, of a resinous compound cast firmly
upon the metal stem and cap dg, according to my invention. It will be seen
that the stem d in extending up into the cast handle greatly strengthens the same,
while the tin cap g lines and strengthens the resinous cap on the inner or
under side, and thus prevents the resinous compound from coming in direct contact
with the smeared lip of the mucilage bottle, and thereby prevents the brush from
adhering to the neck and chipping off, as would be likely to occur if the strengthening
lining were omitted. It may be noted that the molding cavity in the mold a is made
straight down therein, and that the cavity is made without breaks or joints, and (in
correspondence to the design of the brush shown in Fig. 4) it is almost straight, or
tapers or diverges very slightly from its lowest point up, to give necessary "draft"
to the casting. Very little "draft," however, is necessary, and the lines of the design
may be almost or sometimes quite straight, and is thus adapted to admit the direct
upward draft or withdrawal of the casting.
Now referring again to Figs. 1, 2 and 3, the mold a is provided with a top-piecė
or cap h, which has a short neck to enter the mouth or cavity of the mold, and this
neck is formed on the under side with a grooved or beveled rim to correspond to,
and form the under edge of the cap.f, as fully shown in the drawings. A central
boss also projects from the mold cap within the rim, i, adapted to receive and snugly
fit the tin lining-cap y of the brush, as shown in Fig. 2, while the mold cap has also
a hollow center or bore through which the stem of the brush projects, as shown.
Now in proceeding to cast my improved brushes, I prepare a resinous composition
of any suitable kind, which can be fused or melted, and poured in a hot liquid state
into the molds, and which will there rapidly solidify. I will mention that equal
weights of common rosin and powdered silica, with or without any pigment for
coloring, the rosin being first melted and the silica being thoroughly incorporated
therewith, will form an excellent composition for this purpose, being cheap and strong,
and may be run very fluid and will solidify rapidly in the molds without sticking to or

page_text: corroding the same. The addition of the silica or other powdered substance to the
rosin overcomes its brittleness and tendency to chip and crack, and makes a composition
of great tenacity and strength, having five or six times the tenacity of the rosin alone,
and this mixture not only may be run very fluid, but will follow the finest intricacy
of the mold, and cast sharp and true with a fine polished surface. Any other fusible
composition of similar action may, however, be used, that is any resinous composition
or fusible cement which is a running liquid when fused and a strong solid when cold.
The resinous compound having been, therefore, properly prepared, and being
brought to a proper heat and fluidity, is now poured hot and liquid into the mold, as
seen in Fig. 2, the mold being thus filled to a proper height. The cap with the
metal part of the brush attached thereto, as shown, is now pressed down into the mold,
which will complete the casting, as seen in Fig. 3. It will now be seen that the act
of inserting the cap with the brush attached into the liquid charge in the mold will
cause the metal stein and cap of the brush to be embedded in the resinous composition
while hot and liquid, which will now bond and adhere firmly thereto, for the reason
that the mass of the metal in the tin stem and cap is small, and is surrounded by a
comparatively large masss of hot liquid composition which will rapidly heat the metal
parts up to the temperature of adhesion, and thus cement itself firmly to the thin
metal parts of the brush. The composition will not, however, adhere to the body or
cap of the mold at all on account of their mass and their capacity of absorbing the
heat from the composition so rapidly as to prevent the surfaces from reaching anything
near the temperature of adhesion. The result will be, therefore, that in a few seconds
the casting will have firmly solidified, in the mold, and the cap h may be lifted off;
usually bringing with it the cast brush, which will slip freely out of the cavity
the mold, after which a pressure on the end of the brush-stem will remove the
finished brush from the mold-cap, when it will appear as in Fig. 4, with the solidified
resinous compound firmly bound and adhered to the metal parts of the brush. The
finished brush will now present a highly ornamental exterior, having reproduced
every feature of the mold, and with a brilliant polished surface, which makes it a very
desirable article in the qualities of strength, beauty and cheapness, and it is a
great advance in the art as compared with the common tin brushes heretofore used,
or the more expensive brushes having turned wood caps and handles, the cost of
the latter being three or four times that of my brushes. Any lettering stamped
or engraved on the ledge in the mold will, of course, be reproduced with perfect
fidelity on the top of the cast brush, thus forming the brush, and lettering it at
the same instant.
of
It will be further noted, referring to Figs. 1, 2 and 3, that the neck and rim, hi,
of the mold-cap, form or finish the edge of the brush-cap, and that the only joint in the
mold is therefore a circumferential one at the extreme angular edge on the circum-
ference of the brush-cap, where any fin or seam, if it does occur is not noticeable.
It will therefore be seen that in my mold and method of casting, the top or opening
through which the mold is filled is afterwards closed by a cap which fits said opening
snugly, and therefore not only presses or molds the top of the casting into shape and
thus leaves no fin or joint except at the circumferential angle named, but besides this
it leaves no "spud," "sprue" or snag at the pouring opening, as is usual in casting,
for the "
sprue" becomes in fact obliterated in my method, as the inserted part which
is embedded in the casting is inserted at, or covers the pouring opening (or what
would otherwise be the pouring opening and the "sprue") so that, the casting is thus
complete when removed from the mold without requiring to break off any excrescences
thereon.
In Figs. 5, 6 and 7, I illustrate the casting of bottle-stoppers by the same system.
In Fig. 5, k indicates the stopper of cork or other material to enter the neck of the
bottle, and m indicates a head of resinous compound cast on the cork. This head is of
larger diameter than the cork with a broad rim to admit the grasp of the fingers, and
is formed in some nice ornamental design, and with any desired ornamental or
proprietary words on its top, and it thus not only forms an ornamental and effective
proprietary mark or advertisement for the bottle on which it is used, but also serves as
A

page_text: a means whereby the cork can be readily removed or inserted, although very tight-
fitting, without having to resort to cork-screws or without danger of mutilating the
cork, for the reason that as the cast top is much larger than the cork, and has a broad
grasping rim, it affords such a grasp and purchase for the hand as enables the stopper
to be inserted or removed with ease. This rim may be corrugated for better grasp, as
shown, or it may be smooth.
In Fig. 6, a indicates the mold for forming the stopper, which is made of a massive
block of metal, as before described, and formed with a cavity.corresponding to the
shape of the ornamental head, with any desired devices or letters engraved or stamped
on the base, and with its sides very slightly tapering for draft, as will be understood.
This cavity being filled with the molten composition poured therein, as seen in Fig. 6,
the cork or stopper & is then placed on top of the molten mass and sunk a little way
therein, and thus left until the mass solidifies, when the casting with the cork adhering
firmly thereto can be freely lifted out of the mold, and will appear as in Fig. 5. This
forms a very ornamental and cheap stopper, as the material of the head is quite
inexpensive, and the manufacture is very rapid and simple, and, moreover, the head
requires no after fixing to the cork, as in other stoppers heretofore made, but is most
firmly cemented or united with the cork in the very act of formation, and furthermore
the nature of the material forming the head gives a better grasp to the hand, and admits
of more ornamental effects than is the case with the attached wood and metal heads
heretofore used.
0
In some cases the stopper-mold may be provided with a cap h, like the brush-mold,
as shown in Fig. 7, in which cap h; the cork will be inserted with its base protruding a
little therefrom so as to become embedded firmly in the molten composition when
the top is inserted in the mold after filling the same with the composition, as
illustrated in Fig. 7. This will enable the corks to be placed more accurately, and
embedded more deeply in the resinous head than would be the case in Fig. 6. In
some cases the corks used in Fig. 7 may be perforated at the center to allow some
vent to the composition; or the corks used may be shell corks, with a large hollow
center or bore, as indicated by dotted lines in Fig. 7, and the corked cap may first
be placed in the mold and the mold and hollow cork then filled up by pouring the
composition in through the top of the hollow cork, thus binding the composition
more firmly to the cork.
The molds and their caps for my system are preferably made of good brass in
massive blocks or pieces, but they may be made of other metal or material that is
a good conductor or absorber of heat, but brass is considered practically the best.
In some cases the molds might be made of a thin metal shell, say, for instance,
an electro-type shell, filled with water or similar rapid heat absorbent, as indicated
in Fig. 8, but the solid massive brass or metal mold is preferred.
My system of casting is not of course confined to a composition which is strictly
or chemically resinous, as any similar fusible and solidifiable composition may be used,
for instance sulphur combined in equal proportions with silica or any equivalent
powdered substance. The great objection to a sulphur composition, however, is that
it will rapidly cause corrosion of the metal molds and thus adhere thereto by virtue of
corrosive adhesion. This may be obviated, however, in a great degree by plating the
brass or other metal molds with gold or platinum or similar metal which is proof
to the action of sulphur.
Waxes and fats as a general thing cannot be readily cast by my system, as they seem
to adhere to dry metal molds whether cold or hot, whereas resinous or sulphurous
compounds will not adhere to cold, dry metal molds, although in the case of sulphur if
the mold becomes corroded thereby the casting will then stick, but not otherwise.
It will be readily understood that the advantage of my system in obviating oiling of
the molds is not only that time and trouble is thus saved, but the surface of the casting
is much more perfect and shows a fine smooth polished surface, which would be dull
and rough if the mold had to be smeared with a lubricating or non-adhesive film.
In making my improved castings as before described, a series of the molds should
be used each being filled in succession and left to cool until all are filled, when the

page_text: casting is then removed from the first one and the first is then again filled, and so on
successively to the end of the series, by which means the molds are allowed sufficient
time to cool down, or rather the heat is prevented from accumulating therein to the
temperature of adhesion, which is near the point at which the composition softens.
It may now be appreciated that my invention provides a cheap and simple process
whereby a great variety of articles may be produced from a very cheap and strong
composition, and yet present a very ornamental and attractive appearance. This
composition is very durable and pleasant to the touch, and may be exposed to the heat
and light of the sun, and to high atmospheric temperatures in any climate without
becoming either soft or sticky. The articles are much superior in finish and
ornamental effect to similar ones produced in wood, metal, glass or pottery, and are
much cheaper, which facts will commend my invention for a great many purposes to
which it is adapted.
I reserve the novel articles or products here shown, such as the stoppers and brushes,
for the subjects of specific patents.
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 :-
1st. The improved art of resinous casting herein set forth consisting in first
preparing a resinous compound or fusible cement which is a running liquid when fused
and a strong solid when cooled and in employing molds made of massive blocks
of metal, or other good heat conductors, thence pouring the hot liquid compound into
said molds while the said molds are cool and dry, allowing the composition to solidify
therein, and finally removing the solidified castings, whereby pressure, lubrication and
sticking are obviated and sharp polished castings are produced rapidly and cheaply,
substantially as herein set forth.
2nd. The art of resinous casting herein described consisting in pouring the
composition while hot and liquid into cool dry molds made of a metal or good
conductor of heat and employing a successive number or series of said molds which are
filled in succession or rotation, allowing the castings to solidify and cool in the
successive molds, and removing the castings and refilling the series in successive
cycles, substantially as herein set forth.
3rd. In the art of resinous casting the mold blocks such as a having molding cavity
such as sunk therein and formed widest at the mouth to admit of direct outward
draft, in combination with the cap having the neck ¹ tightly fitting the mouth of the
cavity, substantially as and for the purpose shown and described.
h
4th. In the art of resinous casting the combination with the block a having cavity b
of the cap having neck to fit the mouth of the cavity with boss l on said neck,
substantially as shown and described.
5th. In the art of resinous casting the combination with the block a having cavity b
of the cap having neck with groove and boss l, substantially as shown and
described.
a
6th. The art of making resinous casting with a part of heterogeneous material
attached thereto consisting in employing molds having molding cavity sunk therein
and provided with a molding cap or plug to fit the mouth of said cavity, attaching the
heterogeneous part to said cap so that a portion thereof projects on the insertible side,
thence pouring the composition while hot and liquid into the cavity of the mold and
thence inserting said cap or plug in the mouth thereof and thus plunging the attached
or projecting part in the molten composition and causing it to unite with the same and
finish the top of the casting at the same time, substantially as herein shown and
described.
11:
1000