Improvements relating to the Casting of Metals and Alloys.
Year: 1887

page_text: Date of Application, 5th Mar., 1887
Complete Left, 28th Nov., 1887
Complete Accepted, 30th Dec., 1887
PROVISIONAL SPECIFICATION.
Improvements relating to the Casting of Metals and Alloys.
We FRANZ RICHARD SCHWEIGER, and CHRISTIAN FRIEDRICH MÜHLMANN, of
Nicolaistrasse No. 9, Chemnitz, in the Kingdom of Saxony, Manufacturers do hereby
declare the nature of this invention to be as follows:-
It is known, that all molten metals and alloys contain gases and the more so in
proportion to the number of constituents in the alloy. These gases enclosed in the
metal cause the formation of bubbles and flaws impairing the casting. It is therefore
very necessary for obtaining a good casting.
1) To expel the gases from the metal or the alloy while it is liquid.
2) To compose an alloy from as few constituents as possible.
3) To give under these circumstances the most simple alloys an extraordinary
hardness and tenacity without any expensive addition of phosphorbronce or the like.
The improved process consists in casting by means of a peculiarly constructed chill.
The chill, after having been slightly warmed, is greased with lard, preferably genuine
old American lard; the excess of lard is rubbed off with a piece of wool and all
inner parts of the chill are then powdered with soapstone, any excess of which is
removed with a soft brush, and the chill is screwed tightly together. A very suitable
alloy consists of 25 parts of copper and 4 parts of tin. The old American lard in
combination with the soap stone has the peculiarity of forming after the casting an
expanding layer between the liquid metal and the chill. Consequently it is possible
to produce a very compact chill-casting for bronze, red brass and the like.-With
casting in sand moulds, the gases accumulating within the mass tend to press the
mass towards the walls and, as these yield to the pressure, the mould is widened and
contains after the solidification of the casting the bubbles formed in the interior.
It is likewise obvious, that with casting in chills, which are not coated with a mass

page_text: adapted to form, after casting an expanding layer between the liquid metal and the
chill, the gases contained in the metal tend to expand the mould. As this mould
however is rigidly closed and does not yield, the metal is compact at the surfaces
adjoining the chill, while bubbles are still contained after solidification in the interior.
If however, as in our improved process, an expanding layer is formed between the
enclosed mass and all parts of the chill, the gases contained within the metal-mass,
are compelled, as they find everywhere increased resistance, to escape through the
still liquid mass, and the metal mass receives by the compressing action of the layer
expanding on all sides a complete homogenity.

page_text: We, FRANZ RICHARD SCHWEIGER and CHRISTIAN FRIEDRICH MÜHLMANN of
Nicolaistrasse No. 9, Chemnitz in the Kingdom of Saxony, Manufacturers, 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 :-
This invention relates to the casting of metal in chills or moulds of cast iron and
consists in a coating for the interior surface of the chill the object of which is to
expel gases formed in the molten metal to be cast and so form a dense and
homogeneous casting without bubble or flaws.
It is known that in casting in chills in the
the molten metal they are not easily expelled
in the interior thereof.
usual manner if bubbles are formed in
from the casting and usually remain
The object of our invention is to coat the interior of the chill with a suitable
material, which when the molten metal or alloy is poured in will expand by the heat
and so compress the molten metal on all sides that bubbles of gas contained in tho
metal are expelled through the ingate and a perfectly homogeneous casting is
formed.
For this purpose the chill is slightly warmed and the interior is coated first with
old lard the excess of lard being removed with a soft rag or piece of waste. Powdered
soapstone is then sprinkled over and well worked in with a soft brush. Excess of
soapstone being removed, the parts of the chill are bolted together in the usual
manner and the molten metal or alloy poured in.
A very suitable alloy consists of 25 parts of copper and 41 parts of tin. The
old American lard in combination with the soapstone has the peculiarity of forming
after the casting an expanding layer between the liquid metal and the chill. Con-
sequently it is possible to produce very compact chill casting for bronze red brass
and the like. With casting in sand moulds the gases accumulating within the mass
tend to press the mass towards the walls and, as these yield to the pressure the mould
is widened and contains after the solidification of the casting the bubbles formed in
the interior. It is likewise obvious, that with casting in chills which are not coated
with a mass adapted to form, after casting, an expanding layer between the liquid
metal and the chill, the gases contained in the metal tend to expand the mold.
this mold however is rigidly closed and does not yield the metal is compact at the
surfaces adjoining the chill, while bubbles are still contained after solidification
in the interior. If however as in our improved process an expanding layer is formed
between the enclosed mass and all parts of the chill, the gases contained within the
metal mass are compelled, as they find everywhere increased resistance, to escape
through the still liquid mass, and the metal mass receives by the compressing action
of the layer expanding on all sides a complete homogenity.
As

page_text: Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is:
In the casting of metal or alloys in chills:
A chill having its inner surface coated with a layer of a material adapted to expand
by the introduction of molten metal, substantially as and for the purpose set forth..
Dated this 28th day of November 1807.
F. R. SCHWEIGER.
C. F. MÜHLMANN.
By Herbert & Co.,
18, Buckingham Street, Strand, London, W.C.,
Agents to Applicants.