A NEW OR IMPROVED PROCESS FOR PRODUCING HOMOGENEOUS METAL-CASTINGS AND
Year: 1883

page_text: LETTERS PATENT to Gerard Wenzeslaus von Nawrocki, Proprietor of the firm
of J. Brandt & G. W. v. Nawrocki, Patent Solicitor and Civil Engineer of
124, Leipzigerstrasse, Berlin, Germany for an Invention of A NEW OR
IMPROVED PROCESS FOR PRODUCING HOMOGENEOUS METAL-CASTINGS, AND
A communication from W. G. Otto, a person
APPARATUS FOR THE SAME
resident at Darinstadt, in the German Empire
PROVISIONAL SPECIFICATION left by the said Gerard Wenzeslaus von
Nawrocki at the Office of the Commissioners of Patents on the 15th January
1883.
GERARD WENZESLAUS VON NAWROCKI, Proprietor of the firm of J. Brandt
& G. W. v. Nawrocki, Patent Solicitor and Civil Engineer of 124, Leipzigerstrasse,
Berlin Germany, "A NEW OR IMPROVED PROCESS FOR PRODUCING HOMOGENEOUS
METAL-CASTINGS, AND APPARATUS FOR THE SAME," a communication from W. G.
Otto, a person resident at Darmstadt, in the German Empire,
For obtaining the highest degree of homogeneity in metallic alloys, a continued
and careful stirring of the liquid metal is an essential condition. For this purpose
I employ a stirrer carrying at its lower extremity a piece of marble or other
mineral capable of giving off carbonic acid. The carbonic acid liberated while
stirring the metal contributes much to obtain a perfect mixture. The marble-block
or other suitable mineral may be attached to the stirrer in any convenient manner,
but preferably by means of dove-tail or T shaped grooves or sockets.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Gerard Wenzeslaus von Nawrocki in the Great Seal Patent
Oflice on the 14th July 1883.
GERARD WENZESLAUS VON NAWROCKI, Proprietor of the firm of J. Brandt
& G. v. Nawroki, Patent Solicitor and Civil Engineer, of 124 Leipziger-Strasse, Berlin,
Germany A NEW OR IMPROVED PROCESS FOR PRODUCING HOMOGENEOUS METAL-
CASTINGS, AND APPARATUS FOR THE SAME " n communication from W. G. Otto, n
person resident at Darmstadt, in the German Empire.
For obtaining the highest degree of homogeneity in metallic alloys a continued
and careful stirring of the liquid metal is an essential condition. For this purpose
I employ a stirrer carrying at its lower extremity a piece of marble, dense chalk or
other mineral capable of giving off carbonic acid. The carbonic acid liberated while
stirring the metal contributes much to obtain a perfect mixture. The chalk or
marble block or other suitable mineral may be attached to the stirrer in any
convenient manner, for instance by means of a dove-tail or T shaped groove or
socket.
The porosity of metal castings, which now and then occurs, is in all probability
due to the presence of some gases occluded by the melted metal, which gases must
be driven off.
This the carbonic acid will effect in the most satisfactory way, without
endangering the quality of the casting, because it is not absorbed by molten
metal.
Lastly the carbonic acid vapours protect the metal, while it is poured out, so as
to prevent the absorption of oxygen from the air.
Claim: The use of a stirrer provided with a block of marble dense chalk or 2
other mineral capable of giving off carbonic acid, for the purpose set forth.
In witness whereof I, the said Gerard Wenzeslaus von Nawrocki, have
hereunto set my hand and seal this 12th day of July A. D. 1883
GERARD WENZESLAUS VON NAWROCKI. (L.s.)