Improvements in Moulds for Casting Magnesium Compositions and similar Cements.
Year: 1899

page_text: COMPLETE SPECIFICATION,
Improvements in Moulds for Casting Magnesium Compositions and
similar Cements.
We, RUDOLF TELLENKA, of 62, Dresdnerstrasse, Chemist, JOHANN THOLBINGER,
of 16, Riemergasse, Manager, and Dr. STEFAN HAGYI-RISTIC, of 13, Singerstrasse,
Gentleman, all of Vienna, Austria, 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 improvements in moulds for casting magnesium com-
positions and similar cements.
Although magnesium compositions have a great many good qualities little use
has hitherto been made thereof even for plain castings as the same rapidly affects
the metal from which the mould is made.
This defect is noticed to a very disagreeable extent in the production of most
primitive objects as it is a matter of importance to retain the dimensions which is
naturally almost an impossibility in moulds affected by the casting material.
This invention has for its object to provide an acid resisting mould material
whereby castings of various forms say, plates, type boxes, type for posters,
ornaments and the, like can be produced accurate and cheaply.
This improved mould composition consists of a mixture of equal parts of
sulphur and Portland cement to which are added about 10 per cent. iron filings.
It is obvious that a good quality of sand, brick dust, ashes or other powdered
inorganic substances may be used in lieu of Portland cement, provided the same
will not free the water at the temperature at which the sulphur melts as the same
would cause air holes and unevenness.
The mould formed in one or more pieces of the mixture described is then
saturated or coated with molten sulphur poured into the same the low melting
point of the mould material about 120 degrees C, the fluidity and the fact that
same cools without altering its volume, ensuring the correct casting of the object
desired.
It is advisable to form the portions of the mould which are to produce flat
surfaces in the casting, of ground sheet glass or metal.
The casting when cold is very strong and tough, requires no finishing what-
has mirror like surfaces sharp edges and resists diluted acids.
ever,
By the use of my improved moulds the use of magnesium compositions will be
greatly facilitated as the object to be cast may be of a more complicated nature
as hitherto has been the case; plain moulds such as quods, plates and the like
which have been found to answer exceedingly well in printing, but the use of
which has hitherto been prohibitive, owing to its expensive production, are for
instance likely to replace the lead type forms and the like now in use.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
wo claim, is:-
1
1st. Moulds for casting objects from magnesium and similar compositions, con-

page_text: sisting of a mixture of about equal parts of sulphur and powdered substances not
liable to give off water when subjected to warmth and acid resisting-such as
cement, brick dust, sand, ashes, to which is added a small quantity of iron filings,
all substantially as set forth.
2nd. In the manufacture of the moulds specified in the preceding claim, the
use of metal or glass, substantially as and for the purpose set forth.
Dated this 5th day of June 1800
F. BOSSHARDT & Co.,
4, Corporation Street, Manchester, Agents to Applicants.