Year: 1887

page_text: Date of Application, 22nd Feb., 1887.
Specification Accepted, 22nd Mar., 1887.
1, ALEXANDER E. OUTERBRIDGE Jr. Inventor, of Philadelphia, Pennsylvania,
United States of America 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 consists in preparing combustible material, such as textile fabrics,
paper, or the like, and designs made thereof and natural objects, such as ferns,
grasses, etc, so that the same may be used either as moulds or as faces for moulds for
metal castings, by converting such substances into a refractory form of carbon, in
which the shape of the material or object is perfectly preserved, permitting molten
metal to be poured directly thereon without changing them, whereby a faithful or
exact copy in reverse or "negative" may be obtained upon the face of the casting,
which may then be used as a die for embossing leather, stamping metal or for other
purposes.
In carrying out my invention I take any desired material such as lace, cloth, or
other fabrics, fibre, etc, or natural objects such as leaves, plants, etc, and carbonize the
same in a suitable manner, thus producing a matrix material retaining its original
form and design, while acquiring new properties of incombustibility, rendering it
suitable for use as parts of moulds for metal castings.
The method of forming a mould in sand which is to be faced with the refractorily
carbonized object does not differ in any way from the ordinary method of making what
is technically termed a "green sand mould" for common castings.
A pattern of the proper size and shape to produce the castings, is laid upon a smooth
board or other surface and the "drag box" of a moulding flask is placed over it,
moulding sand is then sifted over the pattern and rammed down upon it. When the
box is full, it is inverted and the upper half of the flask or cope is put over it. Sand
is sifted over the other side of the pattern as before and when the upper box is full
the flask is opened, the pattern gently rapped to loosen it from the sand, and it is then.
drawn out of the mould. If the carbonized material is sufficiently large to project
slightly beyond the edges of the mould, it does not need to be fastened thereto, since
the closing of the flask securely pins the edges of the material between the cope and

page_text: drag and holds it firmly in its proper position. Suitable runners or gates having been
provided, the molten metal is poured into the mould and the carbonized material
yielding to the pressure of the metal, is forced against the wall of the mould on one
side and is partly embedded upon the casting upon the other.
Experience has proved that the most delicate carbonized fabrics are easily manipu
lated in this manner without risk of breaking or becoming otherwise injured by the
pressure of the incoming metal. Even though the surface of the mould be convex,
concave or irregular in shape, the carbonized fabric will accommodate itself to such
irregularities of surface without tearing.
If the design is too small to admit of this method of treatment, it may be readily
attached to the surface of the mould by means of small pins made of carbonized wood
or fibre, or other refractory substance.
If desired, the face of the mould upon which the carbonized material is to be laid
may be formed from a plate of carbon, iron, or other substance capable of resisting the
heat of the molten metal. The carbonized design may either be laid upon the plate
and fastened at the edges in the manner described, or it may be glued to such substance
with flour paste, molasses, or other adhesive material and then thoroughly dried or
baked in an oven. I have found that several castings may be made from one carbonized
design attached to carbon or metal plates in this manner.
The method of forming a "dry sand" mould for use with carbonized designs does
not differ from ordinary practice. The design may be either loosely laid on the face
of the mould and held at the edges, or it may be glued to the wall of the mould before
baking, as already described.
may also
prepare a matrix or mould by mixing saw-dust, wood-pulp, finely ground
carbon (such as anthracite, coal-dust &c.) with molasses, glue, coal tar, pitch, etc,
making a paste, dough or plastic compound which is pressed upon any form or pattern,
which it is desired to reproduce in metal, and treating the compound as will be herein-
after described, so as to produce a hard carbon mould suitable for making therefrom
one or more castings.
The method of producing carbonized articles may be varied, but in their production
three important principles are involved, as follows:-
First. Partial exclusion of air and substitution therefor of a carbon atmosphere in
the carbonizing receptacle; second, slow distillation of volatile elements in the
materials; third, intense and prolonged heating of the partly charred materials in the
receptacle in order to drive off remaining foreign elements, and to change the carbon
from its readily combustible form of ordinary charcoal into a more refractory condition.
The objects to be carbonized are first preferably saturated in their interstices with
finely powdered carbon, (ground anthracite coal or other form of carbon is used).
They are then packed either in an iron case, a black lead crucible, clay retort, or any
other receptacles which will resist a high temperature, say of 1000 degrees Fahrenheit.
The interstices in the receptacle are usually then filled with finely ground carbon, a
closely fitting lid (not hermetically sealed) is put on, and the case with its contents is
heated in an oven at a very moderate temperature, say 300 degrees Fahrenheit for
several hours. By this process of slow heating in a carbonaceous atmosphere, all
volatile compounds are distilled off from the materials, and owing to the exclusion of
oxygen, no oxidation or combustion of the fabrics can occur.
The completion of this stage of the process is indicated by the cessation of smoke
escaping from beneath the lid of the case.
The box or crucible is now gradually heated in a forge or other fire, and then kept
at a glowing temperature for about two hours more or less, after which it is removed
from the fire and cooled.
The contents when taken out of the box are shaken, to remove the coal dust, and
tested in a blast lamp. If the process has not been carried to a sufficient point, the
partially carbonized objects will be found to resemble ordinary charcoal in their degree
of combustibility, that is, they will become ignited and slowly burn even after removal
from the flame, leaving a white ash, and would be unsuitable for the purposes. If
however, the operation is completed, the carbonized objects are found to approximate

page_text: the graphitic form in their refractory character, they can be heated (as before stated)
while hot and on removal from the flame, no combustion whatever is observed, and
finally, when subjected to an intense heat, at the apex of a blow pipe flamo (or oxidizing
point) they may be slowly consumed without leaving any visible ash.
The plastic moulds made of either pulp, papier mache, or of powdered carbonized
substances held together by glue, molasses, etc, are all subjected to a similar treatment,
in order to thoroughly carbonize the compound, otherwise it would be highly dangerous
to attempt to make castings from molten metals in them.. The result of the treatinent
is that all volatile compounds water, or other substances capable of exploding, flaming
or blowing the molten metal out of the mould and destroying it, are removed, and the
mould being unaffected by the molten metal, can be used again unless its form is such
that the contraction of the metal in cooling should destroy it.
The particular method of carbonizing the objects is, of course, susceptible of variation
to suit particular cases, but the scientific principles involved are unchangeable.
I am aware that it is not new to make a sand mould, and face or dust the same with
powdered carbonaceous material for producing a smooth casting, and therefore I do
not claim the same.
Having now particularly described and ascertained the nature of my invention and
in what manner the same is to be performed, I declaro that what I claim is :-
First. A mould, or the face of a mould, consisting wholly or partly of refractorily
carbonized material retaining the shape and outlines or the design of the original
object, substantially as described.
Second. The process of forming a refractory material for a mould, or the face of a
mould, consisting in first slowly heating the objects packed in a suitable receptacle,
whereby the distillation of the volatile elements is effected, and, second, in heating to a
high temperature the receptacle and enclosed carbonized object, substantially as
described, whereby a non-combustible material is obtained, as stated.
Dated th⠀⠀ dov of 1007
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.