IMPROVEMENTS IN MOULDS FOR CASTING
Year: 1860

page_text: Sealed the 22nd February 1861, and dated the 5th September 1860.
PROVISIONAL SPECIFICATION left by the said David Yoolow Stewart
at the Office of the Commissioners of Patents, with his Petition, on
the 5th September 1860.
I, DAVID YOOLOW STEWART, of Glasgow, in the County of Lanark, North
Britain, Ironfounder, do hereby declare the nature of the said Invention of
"IMPROVEMENTS IN MOULDS FOR CASTING," to be as follows, that is to say:-
This Invention has for object the formation of moulds for iron castings, in
such a way that a succession of castings may be taken from them, such moulds
also producing more or less chilling of the castings.
In a mould made according to one modification of the Invention, the sand
or mould material is held between a series of metal ribs or other convenient
projections, such projections having surfaces in contact with the pattern or
casting, or so nearly in contact therewith as to prevent the breaking of the
moulded material, and producing a partial chill in the latter. The mould may
be composed or built up of sections, each comprising a series of holding and
chilling projections, or of metal and sand mould material sections arranged
alternately.
According to another modification the mould may be composed or built up

page_text: entirely, or almost entirely of separate metal sections, with thin portions of
sand or other compressible material between them, to admit of the mould
yielding to contraction, or otherwise, whilst in some cases it will not be
necessary to insert such compressible material between the sections.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said David Yoolow Stewart in the Great Seal Patent Office
on the 5th March 1861.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, DAVID
YOOLOW STEWART, of Glasgow, in the County of Lanark, North Britain,
Ironfounder, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifth day of September, in the year of our Lord
One thousand eight hundred and sixty, in the twenty-fourth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
David Yoolow Stewart, Her special licence that I, the said David Yoolow
Stewart, my executors, administrators, and assigns, or such others as I,
the said David Yoolow Stewart, my executors, administrators, and assigns,
should at any time agree with, and no others, from time to time and at
all times thereafter during the term therein expressed, should and lawfully
might make, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN MOULDS FOR CASTING," upon the condition (amongst others)
that I, the said David Yoolow Stewart, my executors or administrators, by
an instrument in writing under my. or their, or one of their hands and seals,
should particularly describe and ascertain the nature of the said Invention,
and in what manner the same was to be performed, and cause the same to
be filed in the Great Seal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said David Yoolow Stewart, do hereby
declare the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement in writing. reference being had to the accompanying Drawings,
and to the letters and figures marked thereon, that is to say:
My said Invention has for object the formation of moulds for iron castings,
in such a way that a succession of castings may be taken from them, such
moulds also producing more or less chilling of the castings.

page_text: And in order that my said Invention may be properly understood and
carried into effect, I have hereunto appended a Sheet of explanatory
Drawings, comprising examples of my improved modes of making moulds.
In a mould made according to one modification of my said Invention, the
sand or mould material is held between a series of metal ribs or other con-
venient projections having surfaces in contact with the pattern or casting, or
so nearly in contact therewith as to prevent the breaking of the mould
material, and producing a partial chill in the casting.
Figure 1 is a longitudinal section of portions of a complete mould for a pipe,
with both external and core portions made according to my said Invention;
Figure 2 is a plan of the upper end of the core bar; Figure 3 is a transverse
section of the complete mould; and Figure 4 is a sectional plan of the bottom
of the mould box with the core bar in section.
In describing first what relates to the part of the mould which shapes the
external surface of the casting, it must be observed that some features to
which it will be necessary to refer belong more particularly to the case of pipes
and similar articles, whilst for articles of other forms various modifications will
be requisite, as the practical founder will understand.
In the example selected for illustration, the box or external case or shell is
in two longitudinal halves A, connected by flanges B, planed or otherwise
shaped to fit accurately together. The contact surfaces of these flanges extend
within the shell, but not so far as to the pattern or casting, the inner ends of
the flanges being shaped, as shown in Figure 3, so as when together to form a
groove C, the sand in which is renewed at each casting, to insure a complete
finish at these parts, where, in the case of pipes, the mould is most likely to
be damaged when removing the casting. The boxes A are shaped internally
with a number of ribs D, disposed longitudinally in this example, and, by
These
preference, normally, or at right angles to the surface of the pattern.
ribs D reach the mould surface, or nearly so, being accurately shaped by
planing, turning, or otherwise to the contour of the pattern, and their inner
edges may present narrow surfaces, as shown in the upper part of Figure 3,
or in cases where little or no chilling is desired, the inner edges may be
In addition to this
chamfered off, as shown in the lower part of Figure 3.
the ribs may be discontinuous, or in separate short lengths, and their edges
The sand or mould.
may be subdivided by notching, as shown in Figure 5.
materia! E is rammed or packed in between the ribs D, and the surface
is made even, or nearly so with the edges of the ribs by means of "scrapers, or
similar instruments guided by the ribs and flanges of the mould box, the mould
being finally dried, and the mould surface treated with black wash in the

page_text: ordinary way.
Instead of the ribs D being formed or cast on the side of the
box or shell A, as shown in Figures I and 3, they may be made separately,
and wedged or otherwise fixed in suitable seats or sockets, as shown in
Figure 6. These seats or sockets may either be formed or cast on the box or
shell, or in the case of pipes and similar articles they may consist of separate
semicircular pieces K fixed to the shell at intervals along the box. With this
arrangement one box may be made to serve for different sizes, either by fitting
in broader or narrower ribs, or by raising the ribs more or less from the
bottoms of the sockets, by means of filling up pieces, or otherwise.
In applying the present Invention to the core portion of moulds for such
articles as pipes, it is preferred to use a collapsable core bar of the simple con-
struction shown in the Drawings. This core bar consists of two pairs of
segments F, G, connected by links to a central bar H, in such a way that the
longitudinal adjustment of this central bar in one direction causes the two
narrow segments F to be drawn inwards, and the two broader ones G. to
follow them, the reverse adjustment causing the segments to be expanded to
the required size. The arrangements on which the collapsing and expanding
depends being already the subject of Letters Patent, it is unnecessary to
describe the details further here. The segments F, G, are, by the present
Invention, formed with ribs d extending to the mould surface, or nearly so,
precisely as in the external portions of the mould, the sand or mould material e
being rammed or packed in between the ribs d, and afterwards shaped
externally by scrapers, or otherwise. Or the ribs may be fixed into sockets or
holders formed or fixed on the segments F, G, as described with reference to
Figure 6. At the joints between the segments grooves or recesses are also
formed to receive fresh sand at each casting, to insure a proper finish at these
parts. In the upper part of Figure 1 a portion of a casting or pattern I is
shown as in its place, whilst in the other parts of Figure 1, and in Figure 3,
the matrix or cavity for the molten metal is distinguished by being black.
According to another modification the mould may be composed or built up
of sections, each comprising a series of holding and (more or less) chilling
projections, or of metal and mould material, sections arranged alternately.
Or the mould may be composed or built up entirely, or almost entirely of
separate metal sections, with thin portions of sand or other compressible
material between them, to admit of the mould yielding to contraction, or
otherwise. In Figure 7 there are shown in plan a number of mould sections
as combined to form a flat mould surface, two such sections being shown in
end view in Figure 8. Each section comprises a number of ribs D projecting
from a back or base J, between which ribs the sand or mould material is

page_text: rammed or packed. These ribs may be chamfered off to a sharp edge, and
they may be serrated in the manner indicated in Figure 5, to reduce their
chilling action when desirable. Or, instead of the ribs projections of various
forms may be used, and such projections may be disposed in various ways to
suit particular forms, or other peculiarities of castings. The ribs or pro-
jections may be formed or cast two or more in one piece, with a base, side, or
back; or each rib or projection may be formed separately, and fixed in sockets
or holders in modes similar to that indicated in Figure 6. In making up a
mould of sections such as have been described, and which may, of course,
vary in shape according to the form of casting for which they are designed,
the sections are fitted into frames or boxes, or are otherwise combined or con-
nected together to form complete moulds, the sections when formed with ribs
being, by preference, arranged so that their ribs run alternately in different
directions, as shown in Figures 7 and 8.
Having thus particularly described my said Invention, and the manner
in which the same is or may be used or carried into effect, I have here to
state that I do not restrict myself to the precise details herein-before described
and delineated, but that what I consider to be novel and original, and claim
as the Invention secured to me by the herein-before in part recited Letters
Patent is, the system of making moulds for casting, wherein the sand or
mould material is held between metal ribs or other convenient projections,
such projections having surfaces in contact with the pattern or casting, or so
nearly in contact therewith as to enable the mould to be used a second time
or oftener with little or no renewal of the mould surface, substantially as
herein-before described.
In witness whereof, I, the said David Yoolow Stewart, have hereunto
set my hand and seal, this Fourth day of March, in the year of our
Lord One thousand eight hundred and sixty-one.
DAV. Y. STEWART. (L.S.).