Improvements in or Connected with the Coating of Certain Metals with other Metals or Alloys.
Year: 1888

page_text: Date of Application, 30th Nov., 1888
Complete Specification Left, 30th Aug., 1889-Accepted, 9th Nov., 1889
PROVISIONAL SPECIFICATION.
Improvements in or Connected with the Coating of Certain Metals
with other Metals or Alloys.
I, WILLIAM CHARNOCK, of 22, Arthur Street, Warrington, in the County of
Lancaster, Foreman, do hereby declare the nature of this invention to be as
follows:-
This invention relates to coating or surfacing iron and steel, with other metals,
such for instance as tin spelter, zinc, or terne.
In coating metals with other metals or alloys by the customary processes of tinning
and galvanization, an alloy or dross is formed, which sinks to the bottom of the vat or
bath of molten metal, which is of a much lower value as a coating agent and as an
article of commerce, than the pure or virgin metal.
The dross or hard precipitate in the virgin metals is formed by the chloride or
sulphate of iron coming into direct contact with the commercially pure or virgin
metals.
The object of my invention is chiefly to prevent as far as possible, the formation of
dross in the bath containing the virgin metal, by removing the chlorides from the
article to be coated before it comes in contact with the virgin metal, and to utilize
the dross or a considerable portion thereof.
In carrying out my invention, the process of coating is conducted in such a manner
that the article to be coated is first caused to come into contact with the molten
dross, thereby removing its deterrent in the virgin metals, then subsequently with the
virgin metal or alloy.
This may be accomplished, for example, by employing two contiguous vats or baths,
or a vat or bath of two compartments in one of which the article to be coated is first
treated, and the other containing molten commercially pure or virgin metal, or alloy,
in which the article is subsequently treated. Any superfluous dross, which has not
been removed in the first bath is removed from the article during its treatment in the
second bath. This collects at the bottom of the vat and can be removed from time to
time to the first or dross bath.
COMPLETE SPECIFICATION.
Improvements in or Connected with the Coating of Certain Metals
with other Metals or Alloys.
I, WILLIAM CHARNOCK of 22 Arthur Street, Warrington, in the County of
Lancaster, Foreman, 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 :—
In coating certain metals such as iron or steel with other metals or alloys, such for
instance as tin, spelter, zinc or terne, by the customary processes of tinning or
galvanisation, an alloy, dross or hard precipitate is formed, which sinks to the bottom
of the vat or bath of molten metal, and is of a much lower value as a coating agent
and as an article of commerce, than the pure or virgin metal.
It is in relation to such metals capable of forming such precipitate that this, my
invention refers

page_text: The object of my invention is chiefly to prevent, as far as possible, the formation of
the hard precipitate in the bath containing the virgin metal, and also to utilise such
hard precipitate or a considerable portion thereof.
In carrying out my invention, the process of coating is conducted in such a manner
that the article to be coated is first caused to come into contact with the hard
precipitate in a molten state and then subsequently with the virgin metal or alloy.
The process may be understood by reference to the accompanying drawing, which
shows one way in which the invention may be applied to the tinning or galvanizing
of iron or steel wire.
I employ two vats or baths, A A', preferably contiguous, or a vat or bath having
two compartments. In one of the baths, say A, the article to be coated (in this case,
the wire B) is first treated by being passed through a quantity of molten hard
precipitate C. In the vat A, the wire becomes coated with the hard precipitate.
After passing through the bath A, the wire is next passed through the pure or
virgin metal or alloy C¹ in the bath A. By this means, any superfluous hard
precipitate is removed from the wire and the coating on the latter receives a fine
smooth finish. The above superfluous precipitate collects at the bottom of the vat A',
and it may be removed from time to time, by means of a perforated ladle, and placed
in the first bath A, or other place, as desired.
It may sometimes be useful to add a little virgin metal to bath A if it becomes
too hard.
a a are rollers upon which the wire runs in its course through the baths, and a¹ a¹
are adjustable forks or guides for keeping the wire submerged in the contents of the
baths.
It will thus be seen, that, by my invention, the hard precipitate is utilised for the
purposes of coating the wire, while the pure or virgin metal or alloy is employed
for finishing purposes only. A great saving in the cost of manufacture is thus
affected.
It will be obvious that the invention is also applicable to the tinning or galvanising
of articles other than wire.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what
I claim is:
1. The improvement in the process of coating metals, such as described, with tin
or other metals or alloys, as described, which consists in first treating the metal to be
coated in a molten bath of the "hard precipitate" of the coating metal or alloy, and
in then treating it in a bath of pure or virgin metal or alloy, substantially as and for
the purposes set forth.
2. The improved apparatus for tinning or galvanising metals as iron or steel, con-
structed as a whole substantially as described and shown.
Dated this 29th day of August 1889.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Patent Agents for the Applicant.