Improvements in the Method and Apparatus for Annealing Copper Wire and Sheets.
Year: 1891

page_text: Date of Application, 7th Mar., 1891- accepted, 25th Apr., 1891
COMIDELE DI MUIT
Improvements in the Method and Apparatus for Annealing Copper
Wire and Sheets.
I, THOMAS WILLIAM JOHNSON, of 23, Great Sutton Street, E.C., Manu-
facturer, 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 :-
My invention relates to improvements in the method and apparatus for annealing
copper wire and sheets and has for its object to dispense with the tedious and
expensive operation known as "pickling
"which had to be heretofore practised
after the copper wire or sheet had been annealed in order to obtain a clean product.
This operation was rendered necessary owing to imperfections attached to the
annealing stage of the process by means of which the wire is softened, finished and
cleaned after it has been previously drawn to the fineness required.
Now my invention has for its object to produce by fully remedying these imper-
fections or defects a copper wire or sheet of much greater brilliancy and purity
than heretofore, while considerably increasing its elasticity, uniformity of texture,
and tensile strength, this being effected without "pickling" and without the wire
or sheet being subjected to a preliminary oxidation such as unavoidably occurred
when treating the metal by former methods. The saving of labour effected in
carrying my invention into practice is also a very important feature which is partly
due to the particular form of vessel or pot which I use for annealing the copper
wire or sheet.
I shall now proceed to describe my process and apparatus for the treatment of
copper wire, the same however will also apply for copper sheets with this difference,
that instead of using a circular pot, I make use of long cases of similar construc-
tion. In the accompanying drawings Fig. 1 is a sectional view of my improved
annealing pot and Fig. 2 a plan of the same with the lids removed. The copper
wire having been drawn to the required size is first soaked in water in superposed
layers or coils or in any other suitable manner; the object of this preliminary
soaking is to render the wire more pliable for winding purposes, this wire being
afterwards drained and placed in layers, coils or otherwise in my improved pot.
This pot consists of three concentric pots a be, fitting closely one within the
other and the first of which is preferably of iron while the other two are preferably
of copper.
Each pot has its own lid or cover a¹¹c¹ of similar material, the last two i.e. b
and having preferably an upturned edge or rim while the first, that is to say the
lid a' has preferably a bent down edge or rim. The three lids are each provided
with a handle in the centre and the outer pot or casing a is also furnished with
handles h. The innermost pot c is not so tall as the pot b which is likewise shorter
than the outer pot or casing a as clearly shown in Fig. 1. The wire W is placed
in the inner pot c until the latter is filled when the lid c' is placed thereon and
carefully luted around its outer periphery against the inner periphery of the pot
as shown at d in Fig. 1. This luting is composed of white lead and putty mixed
in equal proportions, and is coated with a layer of red lead and oil.
b
The pot is now filled up with finely pulverized and sifted burnt wood dust,
piled upon the lid c', and the lid is placed in position on the top of the pot b,
when a further quantity of the same finely pulverized, and sifted burnt wood dust
is placed upon the lid until the outer pot a is full. The lid a' is now placed on
the latter pot and secured thereon in any suitable manner, and the whole apparatus
is introduced in a heated furnace of any suitable construction, and raised to a red
heat for a length of time depending upon the size and class of furnace used,
generally about an hour.

page_text: This annealing process softens the wire without injuriously affecting its surface
which is found as the apparatus is subsequently withdrawn and the lids a¹ b¹ c¹
successively removed, with a brilliant colour and a glossy soft and silky appearance
ready for immediate use for the purpose for which it is required. I may dispense
with the outer casing of iron and use only two copper pots, and one layer of
finely pulverized and sifted wood dust, but I prefer using the process as above
described.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is
The improved process and apparatus for annealing copper wire and sheets
consisting in previously soaking the wire in water placing it in the innermost and
shortest pot of an apparatus comprising three concentric pots of graduated
heights a b c viz.-an outer iron casing or pot and two copper pots, this innermost
pot c furnished with a luted cover c¹ surmounted by a layer of finely pulverized and
sifted wood dust extending upwards to the upper edge of the pot 6 which is sub-
sequently covered with a lid likewise surmounted by a layer of finely pulverized
and sifted wood dust extending to the upper edge of the outer pot a, also provided
with a lid a', the whole apparatus being raised to a red heat in a furnace sub-
stantially as herein described and shown, and for the purpose set forth.
Dated this 7th day of March 1891.
RAYNER & CASSELL,
37, Chancery Lane, W.C., Agents for the Applicant.
RAYNER & CASSELL,
37, Chancery Lane, W.C., Agents for the Applicant.