IMPROVEMENTS IN CASTING IRON AND STEEL, AND IN APPARATUS EMPLOYED FOR THIS PURPOSE.
Year: 1865

page_text: LETTERS PATENT to Joseph Whitworth, of the City of Manchester, in
the County of Lancaster, Engineer, for the Invention of "IMPROVEMENTS
IN CASTING IRON AND STEEL, AND IN APPARATUS EMPLOYED FOR THIS
PURPOSE.'
"
Sealed the 16th February 1866, and dated the 24th November 1865.
PROVISIONAL SPECIFICATION left by the said Joseph Whitworth, at the
Office of the Commissioners of Patents, with his Petition, on the
24th November 1865.
I, JOSEPH WHITWORTH, of the City of Manchester, in the County of
Lancaster, Engineer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN CASTING IRON AND STEEL, AND IN APPARATUS EMPLOYED FOR
THIS PURPOSE," to be as follows:--
When casting articles of iron or of steel I submit the liquid metal as
quickly as possible after it is poured into the mould to very heavy pressure,
even to the extent of tons on the square inch, by means of an hydraulic or
other press; aud in order to be thus enabled to apply such heavy pressure to
the fluid metal whilst in moulds I find it necessary to construct the moulds
employed of metals not hitherto used in constructing the moulds in which

page_text: castings of iron or steel are to be produced. To admit of the employment of
sufficient pressure to the metal when in its hottest and most fluid state, I
make the mould or mould box of steel, or in some cases of wrought iron. I
arrange the several parts of the mould or mould box that they may be firmly
fixed the one to the other by screw bolts and nuts or otherwise so as to be
able to resist the great pressure applied to the fluid iron or steel therein, and
I prefer to employ cast steel in the construction of such mould or mould box.
When the fluid iron or steel has been run into a mould the pressure is applied
to the liquid metal by means of one or more plungers passing through closely
fitting collars formed in connection with the mould or mould box. By these
means I prevent the formation of air bubbles in the metal, and thus at the
critical juncture when the metal is passing from the fluid to the semi-fluid
state I prevent any part of the casting from becoming hollow or unsound.
A steel casting thus made when subjected to a hardening and tempering
process such as the one for which a Patent was granted to me, dated the
5th day of November 1863, No. 2743, will be found to be much more uniform
and reliable than a steel forging prepared in the usual manner.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Joseph Whitworth in the Great Seal Patent Office on the
24th May 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOSEPH
WHITWORTH, of the City of Manchester,in the County of Lancaster, Engineer,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fourth day of November, in the year of our
Lord One thousand eight hundred and sixty-five, in the twenty-ninth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Joseph Whitworth, Her special licence that I the said Joseph
Whitworth, my executors, administrators, and assigns, or such others as I,
the said Joseph Whitworth, 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 CASTING IRON AND STEEL, AND IN APPARATUS EMPLOYED FOR
THIS PURPOSE," upon the condition (amongst others) that I, the said Joseph

page_text: Whitworth, 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 Joseph Whitworth, do hereby declare the
nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof, reference being had to the Drawings hereunto annexed,
and to the figures and letters marked thereon, that is to say:―
This Invention consists in forming and employing moulds of steel in
combination with pressing plungers in such manner that fluid steel when
in such moulds is subjected to very high degrees of pressure. Articles of
steel so manufactured are greatly superior to other articles made as heretofore
of cast steel in moulds formed of other materials than steel, whilst at the
same time the waste heretofore resulting from the previous modes of casting
is avoided. I would state that it has been before proposed to subject steel
when in moulds to pressure, but the materials used in constructing the moulds
employed and the pressure applied have been inadequate to the production of
sound castings of steel, neither has the pressure been applied so quickly to
the fluid steel as is necessary. I have ascertained in the course of experiments
that cast iron, which is the material heretofore very commonly used in con-
structing moulds, is incapable of bearing those high degrees of pressure which
I find to be necessary in order to obtain practically and usefully those benefits
which result from using very high degrees of pressure on fluid steel in moulds
of steel combined with plungers actuated by hydraulic or other pressure.
DESCRIPTION OF THE DRAWINGS.
Figures 1 and 2 show two plans in section of moulds used when casting
ingots or bars of the two sections shown, and in like manner may the interior
of moulds be formed for producing ingots or bars or bodies of other transverse
sections. Figure 3 shows a vertical section of the moulds; B is a cylinder of
cast steel made with a slight taper on the inside, say about one in fifty; C, C,
are segments of cast iron which are slightly fluted or grooved longitudinally
and across on the bevilled edges to facilitate the escape of air and gases.
The inner surfaces of the segments are coated over with loam or material
ordinarily used in coating parts of moulds and cores.
D is a collar or cap of
steel attached to the cylinder B by screws E, E.
This cap or collar has a

page_text: hollow through it of the size of the interior of the mould, into which is
fitted the pressing plunger F, which in the arrangement shown is fixed on the
end of the ram I of a hydraulic press, which is the description of press
preferred to be used in all cases, but in place thereof other forms of powerful
press may be employed. The steel mould B is supported on the plunger F
by friction screws G, G, which friction when pressure is applied by the
movement of the ram I is overcome, and the plunger F is forced through
the collar or cap into the mould B, and gives pressure to the fluid steel in the
steel mould; H, H', are surfaces produced on the plungers F, F', by ramming
sand or suitable loam or materials commonly used in making moulds, and
such rammed surfaces are protected at the edges by hoops or rings of tin
plate. When the melted steel or iron has been poured into the mould the
plunger is forced down quickly against the fluid metal, and is there made
secure by any convenient means; at the same time the ram I of the hydraulic
press is put in motion and, as before mentioned, the plunger F is thereby
forced into the mould, and subjects the fluid steel therein to great pressure.
When the determined pressure has been arrived at the mould and its contents
are allowed to stand till the steel has become thoroughly set, or when desired
the casting is taken out of the mould and cooled slowly in an annealing
furnace or otherwise. In like manner will steel moulds be arranged for
casting other forms of articles, such as solid shot for ordnance and shells. In
casting hollow bodies, if the interior diameter be small, I commonly introduce
cores of wrought iron, in which case hollow plungers are used which will
pass over such cores. The forms of the cast steel moulds used in carrying
out my Invention will necessarily vary, depending on the forms of the articles
or bodies to be cast therein, but in all cases care is to be observed that the
various parts or sections of a steel mould are formed to go together and bo
fixed in such manner as to resist the great strain to which the junctions as
well as the other parts of a mould will be subjected.
Figure 4 shows a plan, and Figure 5 a side elevation of a cast-steel mould
having four pressing plungers, three of which are actuated by hydraulic presses
suitable for casting the hoop and two trunnions for a piece of ordnance;
Figure 6 shows a plan in section; Figure 7 shows a longitudinal section of the
core with its internal parts separately; and Figure 8 shows one of the smaller
pressing plungers separately. I would remark that when using two or more
pressing plungers to a steel mould the surface pressure on the fluid metal area
for area should be the same.
The steel mould A is constructed in two parts or halves, which go
together and are fixed by screw bolts and nuts a, a. The two parts at

page_text: their ends are strengthened by the steel rings or hoops b, b. The interior
surface of the steel mould A has sand or suitable loam rammed between it
and the pattern, as shown at B, B. In the centre of the mould is a tube C,
which may be made of cast or wrought iron; it is perforated with numerous
small holes, as is indicated in the Drawings. This tube C at its lower end is
formed with an enlargement C¹, as shown, on which is built the coro E, over
which are placed the segments F, F, of cast iron, which are perforated with
small holes; and the surfaces of the segments against which the fluid metal
comes are coated over with a thin coating of suitable loam. On the top of the
mould at A¹ is a collar of steel, which is fixed by screws e, e, as is shown,
through which collar the upper plunger X' is caused to descend as quickly as
possible on to the fluid steel in the mould immediately the filling thereof has
been accomplished, and the plunger X' is to be held securely whilst the fluid
metal is under pressure; Y is a collar fixed to the lower end of the mould by
screws f,, as is shown, through which collar Y the plunger X passes. The
mould is partly supported by such plunger X being held by the friction
screws G, and the interior of the mould is supported by the pins G¹. The
plunger X rests on and is supported by the ram D of the hydraulic press, by
which the requisite pressure is applied to the pressing plunger X when the
mould has been charged, whilst pressure is simultaneously applied to two
other pressing plungers L, L, which are actuated by the hydraulic rams K,K,
of two other hydraulic presses. The hydraulic cylinder J of the rams K are
fixed by screw bolts and nuts c¹, cl, to the flanges H of the steel mould. The
pressing plungers L, L, are faced with sand and have perforations for the
passage away of air and gases; M is a wrought-iron core which is inserted
in the mould, and the pressing plungers L, L, and rams K, K, are made
hollow to pass over them.
It will be evident that the forms and arrangement of moulds to be used
will greatly vary, but an engineer, from the examples above given, will
readily form the steel moulds with the pressing plungers according to the
forms of the bodies or articles to be cast therein. The cast articles when set
are usually taken from the moulds and cooled slowly in an annealing furnace.
I have employed a pressure of about 20 tons per square inch on the fluid
steel in a steel mould when acting on bodies or forms with solid sections of
about four inches diameter, but where metal cores are introduced into the
interior of castings of steel I have obtained very good results when using
about 5 tons to the squarc inch on the pressing surfaces of the plungers. When
no such cores are used I find it desirable in all cases to use greater pressure
than 5 tons on the square inch.

page_text: In the above description of my Invention I have confined myself to the
casting of articlesand bodies of melted steel; but steel moulds with pressing
plungers such as above described are also highly useful when casting bodies
and articles of iron, particularly where heretofore considerable heads have
been used in order to obtain soundness, as by iny Invention the waste and
inconvenience of large heads will be avoided, and as greater pressures may be
used than have heretofore been obtained, from the fluid metal constituting
the heads castings of iron may be obtained of greater strength and tenacity
than heretofore.
In witness whereof, I, the said Joseph Whitworth, have hereunto set
my hand and seal, this Twenty-first day of May, in the year of our
Lord One thousand eight hundred and sixty-six.
JOSEPH WHITWORTH (L.S.)