IMPROVEMENTS IN THE MANUFACTURE OF METAL CASTINGS
Year: 1849

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, DAVID
HENDERSON, late of London Works, in the Parish and County of Renfrew,
Scotland, but now of Gattaway, in the County of Perth, Scotland, Engineer,
send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Twenty-sixth day of
March, (One thousand eight hundred and forty-nine,) in the twelfth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said David Henderson, my exors, admors, and assigns, Her especial licence,
full power, sole privilege and authority, that I, the said David Henderson, my
exors, admors, and assigns, or such others as I, the said David Henderson, my
exors, adfňors, or assigns, should at any time agree with, and no others, from
time to time and at all times during the term of years therein expressed,
should and lawfully might make, use, exercise, and vend, within England,
Wales, and the Town of Berwick-upon-Tweed, in the Islands of Jersey,
Guerney, Alderney, Sark, and Man, and in all Her Majesty's Colonies and
Plantations abroad, my Invention of "IMPROVEMENTS IN THE MANUFACTURE OF
METAL CASTINGS," in which said Letters Patent is contained a proviso, that I,
the said David Henderson, shall cause a particular description of the nature of
my said Invention, and in what manner the same is to be performed, by an
instrument in writing under my hand and seal, to be inrolled in Her Majesty's
High Court of Chancery within six calendar months next and immediately.

page_text: after the date of the said in part recited Letters Patent, as in and by the same,
reference being thereunto had, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
David Henderson, do hereby declare that the nature of my said Invention, and
the manner in which the same is to be performed, are fully described and
ascertained in and by the following description thereof, reference being had to
the Drawings hereunto annexed, and to the figures and letters marked thereon,
that is to say:-
My Invention consists, firstly, in a new method of manufacturing a particular
class of metal castings, videlicet, that in which the whole or a considerable
portion of the casting is of uniform section, as in the case of pipes, whether
straight or curved columns, girders, gutters, ridges, cornices, rails, shafts, and
other similar castings; secondly, in a new method of manufacturing certain
descriptions of circular work, such as pans and basins; thirdly, in the pro-
duction of more than one casting from the same mould; when such moulds are
made as herein-after described.
And I would remark, that my Invention is particularly applicable to the
manufacture of castings of iron, but may also be used for other metals.
The nature of my Invention will be readily understood by a reference to the
accompanying Drawings, which represents its application to the making of
various descriptions of castings, and in which Figures 1, 2, 3, 4, and 5, show
the improvement as applied to the making of small sized pipes; and Figures
6, 7, 8, and 9, the same as applied to large pipés. In these Figurés the samo
letters of reference are employed to distinguish the corresponding parts of
each.
Figures 2 and 7 represent .longitudinal sections; and Figures 4 and 8,
transverse sections of the moulds. The principal part of the box is made in
two parts a, a, divided lengthwise, and when joined, as shewn in Figures 4
and 8, is cylindrical, except where required to be swelled out for the socket, às
shewn in the Drawings, or for flanges or other projections, and thus an uniform
thickness of sand b, or as nearly so as may be, is employed throughout the
entire mould. The parts of the box have a number of small lioles through
them, to allow the gases to escape from the mould when the melted metal is
poured in. I call this form of box a close mould box, to distinguish it froin
the ordinary boxes, which are open at the back, and are fainmed from the
back. in this close mould box; thé back affords a firm support to the sand or
loam, but admits of the escape of air and gas. The ineeting edges c, c, arë
made flat, by planing or filing, so as to fit quite close; and are carried inwards.
until the width between them is equal to the diameter of the pattern forming

page_text: lips, which are made thin at the edge, so as to present a small surface to the
action of the metal during the operation of casting; these edges or lips being
made to follow the external form of the pipe throughout; but as shall be after-
wards shewn, it is not always necessary to allow the metal to come in actual
contact with these lips, but in some cases they are made to admit of a portion
of sand between them and the casting. The lower end of the box is fitted to
rest on a plate d, which supports the core, and at the upper end is fitted to
receive a separate circular box which closes in and completes the upper part of
the mould and forms the gate box, in which a basin and passages for the
metal are formed in sand, and by which the metal is introduced to the
mould.
In preparing the mould, two pieces of pattern are required, onc for the
socket, and another for the body or straight portion of the pipe. These are
only half patterns, as shewn in Figures 3, 5, and 9, where e is the pattern for
the body of the pipe, being merely a short semicylindrical piece of wood or
metal attached to a plate f, which rests on the fitted surfaces of the box, and
is guided either by the inner edges of these meeting surfaces, as in Figure 5,
or by the outside edges, as in Figure 9; and I call this description of pattern
a short part pattern, it being shorter than the body of the pipe, and only
representing a part of the circumference of the 'pipe. In the case of pipes,
I generally make this short part pattern to represent half the circumference of
the pipe, but it may sometimes be advantageous to make it only one-third
part, using three longitudinal mould boxes instead of two. The pattern and
mould boxes may be still further subdivided, but in general two boxes will be
found most convenient.
The ramming up of the mould is commenced by introducing the socket
pattern and fixing it by clamps or screws similar to g, Figures 5 and 9, the
sand or loam is then rammed or filled in behind the pattern from the upper
or open end. The pattern of the body e is then applied before the socket
pattern is removed, and being secured as before-described, the sand is
rammed in as before, the pattern is then slid a short distance along the box,
and again rammed up behind, and so on until the entire box is filled.
Figure 3 represents the box as partially rammed, h being the finished
portion of the mould. If a bead be required at the upper or spigot end of
the pipe, the box is made so that one half of the bead shall be formed in it,
and the other half in the gate box. The upper end of the pattern may be
made with a bead, to serve as the pattern for the lower part of the bead on.
the pipe. The upper part of the bead is readily moulded in the gate box on
a separate board, generally called an odd-side board or laying down board,.

page_text: as is well understood. The core m may be formed by any of the usual
methods, with a plate d at bottom, which fits the mould box and keeps the
core exactly central in the mould. This plate d is covered with loam, and
serves to close the bottom of the mould. In large pipes this is sufficient for
adjusting the core in the mould at top as well as at bottom; but when the 5
plate is small, as in the small pipes shewn in Figures 1 and 2, the gate box i
is made to embrace a central rod j of the core, and as the gate box fits the
top of the mould box the core is thereby adjusted, and held securely in the
centre of the mould. As an additional means of adjusting the two parts of
the mould box, guide pins k may be applied. The different parts of the 1
mould are held together by clamps, screws, or bolts, as at 1, 1, 1, proviously
to their being joined for casting. The parts of the box and core are dried,
but the gate box may be prepared with ordinary green sand. When the
mould is formed of green sand it does not require drying. It is not necessary
that the pipe should in all cases be cast with the socket downwards, the 1
principle being equally applicable to its being made at the upper part of
the mould and flanges, or other projections may be made on the pipes, in a
similar way to that already described for sockets.
Figures 10 and 11 exhibit the application of my Invention to the making
of bend pipes; Figure 10 being a section, and Figure 11 an elevation of a s
mould box complete. This box is somewhat similar to those already described,
but the meeting edges of the two parts of the box are curved, so as to make the
joining along the centre line of the curve of the pipe. In section the box is
precisely similar to that already described for straight pipes, but the short
part patterns are curved, and require curved plates for sliding on the edges of
the box. These Figures shew how the gate box may be dispensed with, the
basin and gates being formed in the upper end of the mould box, which is
swelled out for this purpose. The lower half of the box a is supported in an
upright position by its foot b, the core c is then laid into its place, being
supported at the top and bottom by the surfaces & and e, and is held securely
in its place by the clamp f. The upper half of the box g is then applied,
guided to its proper position by the guide pins h, h, and secured to the lower
part by bolts or clamps i, i, and the metal is poured into the mould by the
cup or basin k, and passes through openings at d to the interior of the mould.
Figure 12 exhibits another method of ramming a mould box which has not s
got close fitting edges all along, and is made without the thin edges or lips
approaching the pattern. The parts of the box merely require to fit at several
points on the meeting edges at a, which are made fair, and out of winding at
these points, so as to lie solidly together; and to guide the pattern, two

page_text: guides b, b, the full length of the box, are fixed temporarily to its sides, with
their upper and straight edges exactly flush with the fitting portions of the
box, and to make the pattern move in a straight line along the box, the
outside as well as the upper edge of the guide 6 is made perfectly straight.
The pattern c is similar to those already described, but has an edge attached
for bearing on the outside of the guide b, to insure straightness in the mould.
The ramming up is proceeded with as before, and when completed the mould
will have its meeting surfaces of sand exactly flat and level with the fitted
portions of the box.
Figures 13 and 14 are sections of mould boxes for gutters, in which the
same principle of moulding is applied, different short part patterns being
employed for the upper and lower halves of the mould; Figure 15 is a
section of a mould of a retort; Figure 16, one for a bearing rail; Figure 17,
one for a girder; Figure 18, one for a grooved roller, of a form which in the
ordinary way of moulding requires a complicated pattern, but by my new
arrangement is as easily moulded as if it were quite plain; Figure 19 is a
section of a mould for a cornice, all of which have the close form of box, and
are rammed with short part patterns guided by the boxes, or by guides
attached thereto, as already described. The retort, Figure 15, and the
cornice, Figure 19, have cores, which are supported at the ends in the usual
manner. The moulds may be formed of green sand, dry sand, or loam; when
formed of dry sand or loam they are dried in the usual manner.
I will now proceed to describe the second part of my Invention. Figures 20,
21, and 22 represent a mould for a circular basin or pan. The mould box is
in two parts a and h, of which a is the external, and the internal part, both
formed so as to have a regular thickness of sand, or nearly so, throughout, and
fitted to each other at f, f. Figure 20 is a section of the outside portion of
the mould box, and Figure 22, a plan of the same, with the pattern 6 in its
position for being rammed; this external mould box is made with a lip fitted
to the form of the edge of the pan; in the centre of the box a socket c is
formed, to admit a pin d on the pattern, this pin is adjusted by collars and a
cotter, so as to be held steadily in the socket, and at the same time admit of
its turning freely round. The pattern 6 has its surface made exactly of the
form of the inside of the mould; the upper end e is made to work on the
fitted part of the box f. It is temporarily fixed while being rammed up
behind by the screw at e, and as the ramming up proceeds, it is turned round
gradually, being supported on its centre at one end, and on the fitted edge of
the box at the other end, and the mould is thereby made perfectly circular.

page_text: After the pattern is removed, the opening in the centre left by the pin is filled
with sand. The other half of the box is rammed in a similar way with a
reverse pattern, the two parts are joined as shewn in Figure 21, and a basin
and gates for the inetal are formed at g. This arrangement may be modified
by having the pattern to extend across the box, with guides the work on to
fitted portions f, so that the centre pin will not be required. In commencing
the formation of the mould, the sand should be rammed under the pattern
from both sides simultaneously, or a board should be placed on one side of the
pattern to confine the sand, whilst it is rammed in from the other side. When
the mould is nearly complete the pattern is shifted on one side, and the mould
finished by hand, and adjusted by again bringing the pattern over it. The
moulds may be made of green sand, dry sand, or loam.
The third portion of my Invention relates to the use of a mould, formed
as already described, for the making of several castings in succession without
the necessity of ramming and drying a new mould for each one, an application
particularly suitable for pipes and other plain castings which deliver easily
from the mould. For this purpose I form the mould of dry sand or loam.
After the metal has been poured into the mould and fairly set, the box is
carefully removed from the casting, the projecting edges or lips of the box
supporting the sand and assisting its removal; the coating of blackwash
usually applied to dry sand moulds is rubbed off, and any damage which the
sand may have sustained made good with fresh sand, and another coat of
blackwash applied while there is yet enough heat in the mould to dry it
thoroughly; a fresh core (if the mould be for a pipe) is then set down, and
the mould box closed round it, and the casting proceeded with as before.
Having now described the nature of my Invention, and the manner in
which the same is to be performed, I wish it to be understood that I am aware
that short moveable patterns have already been used for making moulds for
casting, and therefore I do not claim the use of such patterns except as herein-
after mentioned; but I claim as improvements in the manufacture of metal
castings,
Firstly, the manufacture of pipes, columns, girders, gutters, ridges, cornices,
rails, shafts, and other similar castings in moulds formed by means of a short
part pattern guided by the mould box, or by a guide attached thereto, and
moved gradually along during the process of ramming or filling the mould
box, as above described in reference to the Figures 1 to 19 inclusive.
Secondly, I claim the manufacture of pipes, columns, girders, gutters,
ridges, cornices, rails, shafts, and other similar castings by means of moulds

page_text: formed in close mould boxes with lips fitted to the form of the article to be
cast, as above described in reference to Figures 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,
11, 18, 14, 15, 17, and 18.
Thirdly, I claim the manufacture of pipes, columns, girders, gutters, ridges,
cornices, rails, shafts, and other similar castings in moulds formed in close
mould boxes with lips, such moulds being formed by means of short part
patterns guided by the boxes, or by guides attached thereto, as above described
in reference to Figures 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 18, 14, 15, 16, 17, 18,
and 19.
Fourthly, I claim the manufacture of pans, basins, and similar circular
castings in moulds formed in close mould boxes with lips fitted to the form of
the article to be cast, when such moulds are formed by means of a moveable
part pattern, as above described in reference to the Figures 20, 21,
and 22.
Fifthly, I claim the use of moulds, formed as described in my first, second,
third, and fourth claims, for making two or more castings in succession without
destroying the whole of the moulds, as above described.
In witness whereof, I, the said David Henderson, have hereunto set my
hand and seal, this Twenty-first day of September, in the year of
our Lord One thousand eight hundred and forty-nine.
DAVID (L.S.) HENDERSON.
AND BE IT REMEMBERED, that on the Twenty-first day of September,
in the year of our Lord 1849, the aforesaid David Henderson came before
our said Lady the Queen in Her Chancery, and acknowledged the Specifica-
tion aforesaid, and all and every thing therein contained and specified, in form
above written. And also the Specification aforesaid was stamped according to
the tenor of the Statute made for that purpose.
Enrolled the Twenty-second day of September, in the year of our Lord
One thousand oight hundred and forty-nine.