IMPROVEMENTS IN THE MANUFACTURE OF MOULDS FOR CASTING METALS
Year: 1855

page_text: LETTERS PATENT to Robert Jobson, of Holly Hall Works, near Dudley,
in the County of Stafford, Ironfounder, and John Jobson, of Litchurch
Works, near Derby, in the County of Derby, Ironfounder, for the Invention
PROVISIONAL SPECIFICATION left by the said Robert Jobson and John
Jobson at the Office of the Commissioners of Patents, with their Petition,
on the 15th May 1855.
We, ROBERT JOBSON, of Holly Hall Works, near Dudley, in the County
of Stafford, Ironfounder, and JOHN JOBSON, of Litchurch Works, near Derby,
in the County of Derby, Ironfounder, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN THE MANUFACTURE OF MOULDS FOR CASTING
METALS," to be as follows:-
We construct a plate of iron or other suitable material with an aperture or
apertures through it of the same shape as the pattern or patterns of the articles
to be cast. The pattern is fitted into the aperture or apertures, and is made to
project above the plate to an extent equal to half the thickness of the pattern.
A box is placed over it, and sand is rammed into the box by hand or by
machinery; or the box full of sand is pressed upon the plate and pattern, or the
patterns are forced into the sand, and a sand mould of half the pattern is thus
produced. The mould with the aforesaid plate is raised up, and the sand mould

page_text: is thus removed without injury from the pattern. The plate is then taken off
the mould, which is then complete; or the plate may be only raised a little by
springs or otherwise, so as to detach the mould from the pattern, and the mould
is then lifted off the plate. Thus, in casting iron balls or bullets a number of
pattern bullets are fitted into holes in a plate whose thickness is half the
diameter of the bullet, and which is laid upon another flat metal plate. The
sand is then moulded upon the projecting balves of the bullets, and the mould
and plate are raised a little, so as to draw the mould off the patterns, and the
mould is then removed altogether; the plate is again depressed to its former
position, and another mould is made, and so on. The plate and patterns are
then covered by another flat plate and turned over, and the first flat plate is
removed. Another series of half moulds are then made as before, and one
of each series being placed together, the perfect moulds for the casting of
the bullets are formed. Proper "gates" or passages for the introduction of the
metal are made during the process. The plate may be of a thickness equal to
the semi-diameter of the bullets, or a thinner plate may be used, and the
bullets may rest upon beds of soft metal or other suitable material. The patterns
may also be complete models of the articles to be cast, or they may be models
of one surface or half of the article, and the part below the surface of the plate
may be of different form; but in all cases the sand or mould is drawn off and
detached from the pattern by means of the aforesaid plate. In some cases, in
lieu of moulding one half of the mould in each box, a larger portion may be
moulded in one box and a smaller portion in the other, in each case the
surface of the plate serving to mould the parting surfaces of the moulds. The
boxes and plates are fitted together so that they may all correspond with each
other, and so that the portions of the mould may accurately meet when placed
together
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Robert Jobson and John Jobson in the Great Seal Patent
Office on the 14th November 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, ROBERT
JOBSON, of Holly Hall Works, near Dudley, in the County of Stafford, Iron-
founder, and JOHN JOBSON, of Litchurch Works, near Derby, in the County
of Derby, Ironfounder, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifteenth day of May, in the year of our Lord
S

page_text: One thousand eight hundred and fifty-five, in the eighteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto us, the
said Robert Jobson and John Jobson, Her special license that we, the said
Robert Jobson and John Jobson, our executors, administrators, and assigns,
or such others as we, the said Robert Jobson and John Jobson, our exc-
cutors, 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 THE MANUFACTURE OP
MOULDS FOR CASTING METALS," upon the condition (amongst others) that we,
the said Robert Jobson and John Jobson, our executors or administrators, by
an instrument in writing under our or their bands and seals, or under the
hand and seal of one of us or them, should particularly describe and ascer-
tain 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 John Jobson, on the part of myself and
the said Robert Jobson, do hereby declare the nature of the said Invention,
and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement thereof, reference being bad
to the accompanying Drawing, and to the figures and letters marked thereon,
that is to say-
We manufacture moulds for casting iron balls or bullets in the following
manner: A number of pattern bullets are fitted into holes in a plate, whose
thickness is half the diameter of the bullet, and which is laid upon another flat
metal plate, as shewn in section in Figure 1 of the accompanying Drawing.
A, A, A, are a series of loose or detached patterns fitted into cylindrical holes
or perforations in the plate B, which lies upon another flat plate C. The half
of each pattern thus projects above the plate. A moulding box D is placed
upon the plate B, and sand is rammed in in the ordinary manner, forming the
mould E. The mould E and the plate B are then raised a little, as shewn in
section in Figure 2, so as to draw the mould off the patterns, and the mould is
then removed altogether, as shewn in Figure 3. The patterns are kept in their
proper positions by the perforated plate B, which is again depressed to its
former position, and another mould is inade in the same manner, and so on;
a series of half moulds are thus produced. The corresponding series of half
moulds are made in the following manner :-The plate B and patterns A are

page_text: covered by another flat plate C', as shewn in Figure 4, and the whole inverted,
and the first plate C is then removed. The patterns are thus left upon the
plate C, and are kept in their places by the plate B, the under side of which
is now brought uppermost, as shewn in Figure 5. The second series, of half
moulds are now formed in the same manner as the first series, and one of each
series being placed together, the perfect moulds for the casting of the bullets
are formed, as shewn in Figure 6. Proper "gates" or passages for the intro-
duction of the metal are made during the process. The boxes are all well
fitted to each other, and to the plate B, so as to ensure their meeting correctly.
The plates C and C' are planed on their upper surfaces, and the plate B is
planed on both surfaces.
The perforated plate B may be of a thickness equal to the semi-diameter of
the bullets, as herein-before mentioned; or a thinner plate may be used, being
supported so that its upper surface is level with the centres of the bullets while
the mould is being formed, as shown at P, in Figure 7. In lieu of planing the
plate B or P on both sides, and employing it for moulding both of the half
moulds, two such plates may be employed, and only planed on one side.
These two plates are fixed with their planed surfaces together, and the holes
for receiving the patterns are bored through both plates together, so as to
ensure their correspondence. After making one series of half moulds on the
one plate P, as in Figure 7, the second plate P¹ and a flat plate C' are laid
over the plate P and the patterns A, as shewn in Figure 8. The whole is
then inverted, and the plates C and P are removed. The second series of
half moulds is then moulded on the plate P¹, with the patterns resting upon
the plate C. In lieu of planing the plates C and C' all over, they may be
made with small projections under each bullet, and the tops of these projec-
tions may be planed, or filed, or otherwise adjusted; or these plates may be
faced with lead or other soft metal, or may have recesses containing lead or
other soft metal, and the patterns may be pressed or driven into the soft metal
until they are all adjusted in the same plane. We prefer to employ patterns
of iron or other suitable hard and smooth metal or substance, in order that
they may readily detach themselves from the sand by their own weight when
the mould is raised with the plate.
By the mode of applying the plates B and P, or the double plates P. P¹, we
are enabled to mould several balls or bullets together, and to ensure the correct
meeting of the two half moulds. If it were attempted to mould both half
moulds from the same arrangement of patterns and plate, as, for example,
from that described in reference to Figure 1, it would be necessary to adjust
the positions of the holes in the plate B with very great care, so that the

page_text: patterns might be placed symmetrically on each side of the centre line of the
plate. This might be effected with a single pattern, but would be a difficult
and expensive operation when several patterns are to be employed with the
same plate and boxes, as herein-before mentioned. In casting bullets of one
inch in diameter, twenty or thirty may easily be moulded at once by means
of our Invention.
Having now described the nature of our Invention, and in what manner the
same is to be performed, we wish it to be understood that we do not claim
generally the application of a plate for supporting the sand while the pattern is
being separated from the mould; but what we claim is,―
Firstly, the peculiar mode or modes of manufacturing moulds for casting
metal balls or bullets, by means of a series of three or more loose pattern balls
or bullets arranged in a series of holes or perforations in a plate and resting
loosely upon another plate, or upon a series of supports which are all in the
same plane, and so arranged that the patterns may detach themselves from
the mould by their own weight while the mould is raised or supported by the
perforated plate, as herein-before described.
Secondly, the mode or modes herein-before described of manufacturing
moulds for casting metal balls or bullets, by means of a series of three or more
loose pattern balls or bullets arranged in a series of holes or perforations in a
plate whose thickness is equal to the semi-diameter of the patterns, and which
plate together with the patterns rests upon another flat plate, the whole being
so arranged that the two half moulds may be moulded on contrary sides of the
same perforated plate, as berein-before described.
In witness whereof, I, the said John Jobson, have hereunto set my hand
and seal, this Sixth day of November, in the year of our Lord One
thousand eight hundred and fifty-five.
Witness to the signature of John Jobson,
JONATHAN LOCKWOOD,
22, Morleston Street, Derby.
JOHN JOBSON. (L.S.)