Improvements in Molds, Mold Facings, and Cores used in the Manufacture of Steel and other Metallic Castings.
Year: 1893

page_text: Date of Application, 24th Oct., 1893-Accepted, 23rd Dec., 1893
COMPLETE SPECIFICATION.
Improvements in Molds, Mold Facings, and Cores used in the
Manufacture of Steel and other Metallic Castings.
1, REGINALD HADDAN, of the Firm of Herbert Haddan and Co., of 18,
Buckingham Street, Strand, W.C. London, Patent Agent, do hereby declare
the nature of this invention, a communication to me from abroad by Benjamin
Jones, Molder, of 10 Hope Street Cleveland, State of Ohio, United States of
America, and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement :-
This invention relates to improvements in molds, mold-facings and cores used in
the manufacture of steel and other metallic castings, more especially steel castings,
and in the process of making same, the object being to produce molds, mold facings
or cores capable of withstanding the intense heat had in the manufacture of such
castings and that will shrink with the casting in cooling and will cleave readily
from the casting.
The improved core, mold or mold-facing is made as follows:-Take 5 parts of
clean strong sand, such, for instance, as molding sand to one part of fine combustible
material or substance, preferably flour, and thoroughly mix the same while dry.
The core, mold or mold-facing is built up of said compound, the latter of course
being dampened and tempered suitable for the purpose. The proportion of sand
and combustible substance or material used in making the compound may be varied
more or less according to circumstances, but I would advise the use of too much
rather than too little sand. The core, mold, or mold-facing, having been built up
as hereinbefore described, coal-tar or other suitable binding and hardening substance
or composition is introduced so as to form one compound with the flour or com-
bustible substance and sand of the material of which the core, mold or mold-facing
is composed. This introduction of the coal-tar or binding and hardening substance
is effected by applying the same while in a hot liquid condition to the surface of
the core, mold or mold-facing until the core, mold or mold-facing has become
thoroughly impregnated with it and its gases, the core, mold or mold-facing being
thoroughly dried and heated preparatory to the introduction of the tar. It may be
said that the tar or binding and hardening substance is burnt into the core, mold
or mold-facing. If all the gases in the tar or binding and hardening substance
were retained therein, disastrous results would likely ensue in the operation of
casting, but by introducing the binding and hardening substance as hereinbefore
described, by burning the same into the core, mold or mold-facing enough of said
gases is eliminated to avoid such results.
A core, mold or mold-facing composed as herein before described will not only
withstand the intense heat had in the manufacture of steel castings but will shrink
approximately with the casting in cooling owing to the consumption or burning,
after the operation of casting, of the flour or fine combustible substance in the
material composing the core, mold or mold-facing, and will readily cleave from the
casting.
I would here remark that I prefer to have the core, mold or mold-facing
saturated with the tar or binding and hardening substance, so that the core, mold
or mold-facing shall be as solid as practicable.
Having now particularly described and ascertained the nature of this inven
tion and in what manner the same is to be performed, I declare that what I
claim is.
1. A mold, mold-facing or core consisting of a compound of sand and suitable

page_text: combustible substance impregnated or saturated with a binding and hardening
substance or composition, substantially as set forth.
2. A mold, mold-facing or core consisting of a compound of sand and flour
impregnated or saturated with coal-tar, substantially as set forth.
3. The process herein described of making moulds, mold-facings and cores,
consisting in building up the core, mold or mold-facing of a compound composed of
sand and a suitable combustible substance and then coating the external surface of
the same with a hot liquid binding and hardening substance or composition until
the body of the core, mold or mold-facing shall become impregnated or saturated
with the binding and hardening substance, substantially as set forth.
4. The process herein described of making molds, mold-facings and cores,
consisting in building up the core, mold or mold-facing of a compound composed of
sand and flour in approximately the proportions specified and then coating the
external surface of the same with hot liquid coal-tar and applying the tar until the
body of the core, mold or mold-facing shall become impregnated or saturated with
the tar, substantially as set forth.