Improvements for Use in Producing Castings in Malleable Iron, Mild Steel, and other Metals.
Year: 1896

page_text: PROVISIONAL SPECIFICATION.
Improvements for Use in Producing Castings in Malleable Iron,
Mild Steel, and other Metals.
We, JOSEPH BURGESS, of Acorn Street; Willenhall in the County of Stafford,
Moulder, and WILLIAM ARTHUR BRODIE, of Church View, Gipsy Lane, Willenhall
aforesaid, Moulder, do hereby declare the nature of this invention to be as follows:-
In the casting of metals, and more especially of malleable iron and mild steel,
it has heretofore been found that the light impurities, such as slag, which float upon
the top of the molten metal in the ladle or crucible, are liable to be carried into
the moulds to the detriment of the castings. This objection has been obviated
to some extent by passing the metal through a runner and thence into a cavity
which extends downwards below the bottom of the runner and upwards above the
top thereof, and forming the mould for the "git" through the side of the cavity
at about the level of the runner. The effect of this arrangement is that some of
the impurities float up into the top of the cavity and are thus prevented from passing
through the git opening into the mould; but some of the impurities pass direct
from the cavity into the mould, instead of rising into the top of the cavity. The
runner is sometimes, made to enter the side of the cavity tangentially, to cause
a whirl of the metal within the cavity and thus cause the lighter impurities
to remain in the middle of the whirl so that they cannot pass through the git
opening into the mould. The formation of the cavity, however, has heretofore been
such that the proper whirling of the metal for the purpose cannot be ensured, and
consequently, notwithstanding the precautions adopted, light impurities do pass
through into the mould and the quality of the castings is rendered uncertain.
Now, this invention has for its object to form the lower portion of the cavity,
of such shape that when the molten inetal is brought into the cavity tangentially
from the runner it cannot fail to form a whirlpool within the cavity, with the result
that the light impurities will remain in the middle of the whirl until they have
floated up into the top of the cavity, from which they cannot pass through the
git opening.
The above object is accomplished, according to this invention, by forming the
portion of the cavity from the level, preferably, of the top of the runner, and in any
case from a level not much below, to the bottoin of the cavity, considerably deeper
than has heretofore been, usual, and of a shape which is round in horizontal
section, as has heretofore been usual, but which gathers in to an apex at the
bottom which may be somewhat rounded. We find that the best result is obtained
by forming this portion of the cavity of a conoidal sbape, that is to say, of a conical
shape having the contour of each side formed by a curve which is convex outwardly.
We prefer to form the mould for the runner, for the portion of the cavity which
extends from the top of the runner downwards, and for the git, by means of a single

page_text: pattern, the upper portion of the cavity being formed, as is usual, by a separate
pattern.
Dated this 30th day of December 1896.
STEPHEN WATKINS,
Wolverhampton, Agents for the Applicants.
.
Improvements for Use in Producing Castings in Malleable Iron,
.Mild Steel, and other Metals.
We, JOSEPH BURGESS, of 209 Syston Houses, Beatrice Road, Newfound Pool,
Leicester in the County of Leicester, (late of Acorn Street, Willenhall in the County
of Stafford), Moulder, and WILLIAM ARTHUR BRODIE, of 38 Ivanhoe Street, Newfound
Pool, Leicester, aforesaid, (late of Church View, Gipsy Lane, Willenhall, aforesaid),
Moulder, 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 :-
In the casting of metals, and more especially of malleable iron and mild steel, it
has heretofore been found that the light impurities, such as sluy, which float upon the
top of the molten metal in the ladle or crucible are liable to be carried into
the moulds to the detriment of the castings. This objection has been obviated to
some extent by passing the metal through arrunner and thence into a cavity which
extends downwards below the bottom of the runner and upwards above the .top
thereof, and forming the mould for the "git" opening (that is to say the opening
from the cavity into the mould for the casting) through the side of the cavity at
about the level of the runner. The effect of this arrangement is that some
of the impurities float up into the top of the cavity and are thus prevented
from passing through the git opening into the mould; but some of the
impurities pass direct from the cavity into the mould, instead of rising into the top
of the cavity. The runner is sometimes made to enter the side of the cavity
tangentially, to cause a whirl of the metal within the cavity, the lighter impurities
baving a tendency to remain in the middle of the whirl and be consequently
prevented from passing through the git opening into the mould. The formation of
the cavity, however, has heretofore been such that the proper whirling of the metal
for the purpose cannot be ensured, and consequently, notwithstanding the pre-
cautions adopted, light impurities do pass through into the mould and the quality of
the castings is rendered uncertain:
Now, this invention has for its object to formn the lower portion of the cavity of
such shape that when the molten metal is brought into the cavity tangentially from
the runner it cannot fail to form a whirl-pool within the cavity, with the result that
the light impurities will remain in the middle of the whirl until they have floated
up into the top of the cavity from which they cannot pass through the .git
opening.
The above object is accomplished, according to this invention, by forming the
portion of the cavity from the level preferably of the top of the runner, and, in any
caso, from a level not much below, to the bottom of the cavity, considerably deeper
than has heretofore been usual, and of a shape which is round in horizontal section,.
as has heretofore been usual, but which gathers in to an apex at the bottom which is
preferably pointed, or approximately so, though it may be somewhat rounded. We
find that the best result is obtained by forming this portion of the cavity of a
conoidal shape, that is to say, of a conical shape having the contour of each side

page_text: formed by a curve which is convex outwardly. We prefer to form the mould for the
runner, for the portion of the cavity which extends from the top of the runner
downwards, and for the git, by means of a single pattern, the upper portion of the
cavity being formed, as is usual, by a separate pattern.
In order that the invention may be readily understood, we will proceed to describe
a practical application of the same with reference to the accompanying drawings.
Figure 1 is a side elevation of the pattern for the runner and for the portion of the
cavity which extends from the top of the runner to the bottom of the cavity, and
of the pattern for the upper portion of the cavity. The patterns are shewn as in
position within the mould, the line of parting of the mould being, as usual, at the
level of the upper side of the runner. Figure 2 is a plan of the runner and portion
of the cavity into which it joins, and of the inner end of the git opening, as the same
appear when the upper portion of the mould has been removed and the pattern has
been drawn out of the lower portion. Figure 3 is a section taken on line
of Figure 1.
The portion A of the lower pattern which is to form the portion A¹ of the cavity
in the mould which extends from the level of the top of the runner downwards is
formed of a conoidal shape as shewn. The portion B of the pattern to form the
runner B joins into the upper part of the portion A tangentially, as indicated by
Figure 2; and the upper side of the portion C of the pattern which forms the
git
opening C¹ is level with the upper side of the runner portion B. The pattern D, for
the portion of the cavity which extends above the level of the top of the runner, is
of the usual character and is fitted to the lower portion of the pattern in the usual
manner. The metal is poured, through an opening E through the upper portion
of the mould, into the runner B, and flowing tangentially into the portion A¹ of the
cavity whirls round therein, with the consequence that the light impurities remain
in the middle of the whirl until they have floated up into the upper portion or head
of the cavity, from whence they cannot pass through the git opening.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that
what we claim is :-
1. In producing castings in malleable iron, mild steel, or other metal, the use
of a cavity, between a runner which joins tangentially thereinto and the git opening
into the mould, which is formed to extend some distance above the level of the git
opening and runner and to extend some distance below the git opening and runner,
the lower portion of such cavity, that is to say, the portion from the level of the
top of the runner, or from a level not much below, to the bottom of the cavity, being
of a shape which gathers in considerably towards the bottom, preferably to a point
or approximately so, substantially as described.
2. For use in producing castings in malleable iron, mild steel, or other metal, the
means, which comprise a cavity, between the runner and git opening into the mould,
having a conoidal lower portion, substantially as described and shown by the drawings
herewith.