IMPROVEMENTS IN THE MANUFACTURE OF WIRE, WHICH IMPROVEMENTS ARE ALSO APPLICABLE IN THE MANUFACTURE OF OTHER METALLIC ARTICLES IN THE PRODUCTION OF WHICH THE PROCESS OF ANNEALING FORMS A PART
Year: 1870

page_text: LETTERS PATENT to Richard Hill, Albert Thomas Ward, Wire
Manufacturers, and Carl Friedrich Claus, Chemist, all of Middles-
brough-on-Tees, in the County of York, for the Invention of
"IMPROVEMENTS IN THE MANUFACTURE OF WIRE, WHICH IMPROVEMENTS
ARE ALSO APPLICABLE IN THE MANUFACTURE OF OTHER METALLIC ARTICLES
IN THE PRODUCTION OF WHICH THE PROCESS OF ANNEALING FORMS A PART."
Sealed the 9th May 1871, and dated the 14th November 1870.
PROVISIONAL SPECIFICATION left by the said Richard Hill, Albert
Thomas Ward, and Carl Friedrich Claus at the Office of the
Commissioners of Patents, with their Petition, on the 14th
November 1870.
We, RICHARD HILL, ALBERT THOMAS WARD, Wire Manufacturers,
and CARL FRIEDRICH CLAUS, Chemist, all of Middlesbrough-on-Tees,
in the County of York, do hereby declare the nature of the said In-
vention for "IMPROVEMENTS IN THE MANUFACTURE OF WIRE, WHICH IMPROVE-
MENTS ARE ALSO APPLICABLE IN THE MANUFACTURE OF OTHER METALLIC ARTICLES
IN THE PRODUCTION OF WHICH THE PROCESS OF ANNEALING FORMS A PART," to be
as follows:
.
In the ordinary process of manufacturing wire it is usual to heat the
rod from which the wire is made, or the wire itself, to a bright red

page_text: heat, and to allow it to cool down slowly in order to reduce the metal
to the necessary degree of softness which will allow it to be drawn
to a less diameter. This operation is called annealing, and is carried
on in closed cast-iron tubes or pots in which the rod or wire is placed,
and to which heat is applied externally.
Although in covered or closed receptacles access of air cannot bo
prevented, and in consequence by this, process of annealing the wire
becomes coated with a thin skin of scale or oxide which prevents the
possibility of its being drawn out at once into finer wire. In order to
draw it it is therefore necessary to remove this coat of oxide, and this
is usually done by dissolving off the same by means of a diluted acid,
diluted sulphuric acid being the one commonly used. The application
of the acid at this stage has the effect of rendering the wire brittle or
"rotten," which is especially the case with steel or iron wire. After
cleaning with acid, washing in water, steeping in lime water, and
drying, the wire is ready for being drawn finer (the manner in which
this is accomplished being well known). After having passed through
two, or at most three holes, the metal of which the wire is made has
by the operation of drawing become so hardened that it is impossible,
without risk of breaking it, to draw it any further. The process of
annealing or softening has to be resorted to again and a fresh coating
of scale is formed and has to be removed again. The finer the wire is
required the oftener these operations have of course to be repeated,
and the finer the wire becomes the more detrimental is the action of
acid upon its quality.
What has been said here in reference to wire is applicable also to
all such articles of iron, steel, and copper and brass and similar alloys
which require annealing or softening before their manufacture, that is
to say, hammering, stamping, or drawing can be proceeded with, and to
which the other above-named conditions apply.
The object of this Invention is to avoid some of these disadvantages
and particularly the access of air and the consequent formation of scale
during the annealing process to prevent the necessity of "cleaning "
the wire with acid, and its accompanying consequence of rendering it
brittle or rotten, and further to effect the annealing in very much less
time than that occupied at present.
These objects are accomplished by heating, that is, annealing or
softening the wire or other metallic articles by immersing the same in

page_text: a bath of flux heated to the required temperature necessary for effecting
this purpose.
In this bath the wire or other articles are allowed to
remain until they have acquired the temperature of the same, and until
they have become annealed, when they are withdrawn in the red hot
state. A portion of the flux will naturally adhere to the wire or other
articles forming a coating which will continue to protect the metal from
oxidation until it is cold. When cold the coating of flux is removed
from the annealed articles by means of cold or hot water.
The flux or fluxes employed for the purposes of this Invention may
be composed of one or more substances or of mixtures of various
substances, their other qualities and composition being immaterial so
long as they have, firstly, the property of being only slightly or not at
all volatile; secondly, of having no destructive action upon the wire;
thirdly, of forming a thinly liquid fused mass at red heat; and fourthly,
of being soluble in water after fusion. Of the substances which have
these properties it is preferred to use chloride of calcium, hydrate of
soda, and also silicate of soda, as being cheapest and most suitable, but
common salt, hydrate of potash, borate of soda and potash, silicate of
potash, carbonate of potash, or soda, and substances of a similar
character may also be employed. Mixtures of the above-named
materials may also be used, choosing those substances which when
mixed will not decompose one another.
Fusible mixtures of substances of which only one or more are soluble
in water, the other being insoluble, may also be used, provided the fused
mixture will by means of the solubility of one of its constituents dis-
integrate readily when put into water, so that wire coated with the
fused mixture will become freed from the coating by immersion in
water. Such mixtures are numerous, for instance, a mixture of chalk
or lime and salt has the property of fusing to a thin liquid at red heat
and of disintegrating with water. The bath of fluxes may either be
heated in cast iron or other metal pots or vessels, or in a reverberatory
furnace, the bed of which is in the form of a tank.
The solution resulting from dissolving the flux off the annealed wire
or other articles of metal by means of hot or cold water may be boiled
down and desiccated to be used over again.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Richard Hill, Albert Thomas Ward, and Carl
Friedrich Claus in the Great Seal Patent Office on the 12th May
1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, RICHARD
HILL, ALBERT THOMAS WARD, Wire Manufacturers, and CARL
FRIEDRICH CLAUS, Chemist, all of Middlesbrough-on-Tees, in the
County of York, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fourteenth day of November, in the
year of our Lord One thousand eight hundred and seventy, in the
thirty-fourth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto us, the said Richard Hill, Albert Thomas
Ward, and Carl Friedrich Claus, Her special licence that we, the said
Richard Hill, Albert Thomas Ward, and Carl Friedrich Claus, our
executors, administrators, and assigns, or such others as we, the said
Richard Hill, Albert Thomas Ward, and Carl Friedrich Claus, our exe-
cutors, administrators, and assigns, should at any time agree with, and
no others, from time to time and at all times thereafter during the term
therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
THE MANUFACTURE OF WIRE, WHICH IMPROVEMENTS ARE ALSO APPLICABLE IN THE
MANUFACTURE OF OTHER METALLIC ARTICLES IN THE PRODUCTION OF WHICH THE
PROCESS OF ANNEALING FORMS A PART," upon the condition (amongst others) 1
that we, the said Richard Hill, Albert Thomas Ward,. and Carl Friedrich
Claus, our executors or administrators, by an instrument in writing
under our, or their, or one of their hands and scals, should particularly
describe and ascertain the nature of the said Invention, and in what
manner the same was to be performed, and cause the same to be
filed in the Great Seal Patent Office within six calendar months next
and immediately after the date of the said Letters Patent.
NOW KNOW YE, that we, the said Richard Hill, Albert Thomas
Ward, and Carl Friedrich Claus, do hereby declare the nature of our
said Invention, and in what manner the same is to be performed, to be 3

page_text: particularly described and ascertained in and by the following statement,
that is to say:-
-
In the ordinary process of manufacturing wire it is usual to heat the
rod from which it is to be made, or the wire itself, to a bright red heat,
and to allow it to cool down slowly, in order to reduce the metal to
the necessary degree of softness or ductility which will allow it to be
drawn to a less diameter. This operation is termed "annealing" and
is carried on in covered or closed cast-iron tubes or pots or furnaces in
which the rods or wire are or is placed, and to which heat is applied
externally.
66
Although covered or closed receptacles are employed for this purpose
access of air cannot be entirely prevented, and a consequence of this
process of annealing is that the rod or wire becomes coated with a thin
skin of scale or oxide which prevents the possibility of its being in
that condition drawn out into finer wire. In order to obviate this
difficulty it is necessary to remove the scale or oxide, which is usually
done by dissolving the same by means of a diluted acid, diluted
sulphuric acid, or diluted hydrochloric acid being commonly employed
for this purpose. It should be observed that the application of the
acid at this stage has the effect of rendering the metal brittle or
rotten," which is especially the case with steel or iron wire. The rods
or wire having been thus cleaned with diluted acid and afterwards
washed in water, steeped in lime water and dried, are or is ready for
being drawn to a finer diameter by the well-known means adopted for
that purpose. In practice it is found that after having passed through
two, or at most three holes, the metal of which the wire is made has
by the operation of drawing become so hardened that it is impossible
without risk of breaking it to draw it any further. The process of
annealing or softening has then to be resorted to again and a fresh
coating of scale or oxide is formed which has to be removed as before.
The finer the wire is required to be the oftener these operations have
of course to be repeated, and the finer the wire becomes the more
detrimental is the action of the acid upon its quality.
The previous observations with reference to wire are also applicable to
all such articles of iron, steel, copper, and brass, and of metallic alloys
which require annealing or softening before their further manufacture
by means of hammering, stamping, or drawing can be proceeded with,
and to which the above-mentioned conditions apply.

page_text: The object of our said Invention is to avoid some of these dis-
advantages and particularly to prevent the access of air and consequent
formation of scale or oxide during the annealing process, and to dispense
with the necessity of cleansing the wire with acid, thereby avoiding
the consequence of rendering it brittle or rotten, and further to effect
the annealing in very much less time than by the processes at present
cmployed.
These objects we accomplish by heating, that is to say, annealing or
softening the wire or other metallic articles by immersing the same in
a bath of flux heated to the temperature necessary for that purpose.
In this bath we allow the wire or other articles to remain until they
have acquired the temperature of the same and until they have become
annealed, when they are withdrawn in a red hot state. A portion of
the flux will necessarily adhere to the wire or other articles, forming a
coating which will continue to protect the metal from oxidation until
it is cold. When cold the coating of flux is removed from the annealed
articles by means of hot or cold water.
The flux or fluxes which we employ for this purpose may be composed
of one or more substances or of mixtures of various substances, their
other qualities and composition being immaterial so long as they have,
firstly, the property of being non-volatile or only slightly volatile;
secondly, of having no destructive action upon the wire or other articles;
thirdly, of fusing into a thinly fused mass at a red heat; and fourthly,
of being soluble in water after fusion. Of the substances which have
these properties we prefer to use chlorido of calcium, hydrate of soda,
and silicate of soda, as being the cheapest and most suitable, but hydrate
of potash, borate of soda, borate of potash, silicate of potash, carbonate
of potash, carbonate of soda, chloride of sodium, or other substances of
similar properties and fulfilling the above-mentioned conditions, as will
be well known to and understood by chemists may also be used. We
may also employ mixtures of any of the above-mentioned substances,
choosing those substances which when mixed will not decompose one
another.
Further, we may also use fusible mixtures of substances of which only
one or more is or are soluble in water, the others being insoluble,
provided the fused mixture will by means of the solubility of one of
its constituents disintegrate readily when put into water, so that wire
or other metallic articles coated with the fused mixturo will become

page_text: freed from the coating by immersion in water. The substances of which
such mixtures may be formed are numerous and need not be enumerated
as they are well known to chemists, but as an example of the substances
that may be employed with advantage we may mention that a mixture
of chloride of sodium with lime or chalk has the property of fusing to
a thin liquid at a red heat and of disintegrating in contact with water.
The bath of flux employed for the before-mentioned purposes may cither
be heated in a cast iron or other metallic vessel or in a reverberatory
furnace the bed of which is in the form of a tank.
The solution resulting from the operation of dissolving the flux off the
wire may be boiled down and desiccated to be used again.
Having thus described and ascertained the nature of our said
Invention, and in what manner the same is to be performed, we would
observe in conclusion that what we consider novel and original and
therefore claim as constituting the Invention secured to us by the said
hercin-before in part recited Letters Patent arc, the use of the improved
processes in which are employed chemical agents possessing propertics
such as are above mentioned, substantially, as and for the purposes
hercin-before described and set forth, or any mero modifications thereof.
In witness whercof, we, the said Richard Hill, Albert Thomas
Ward, and Carl Friedrich Claus, have hereunto set our hands
and scals, this Ninth day of May, in the year of our Lord One
thousand eight hundred and seventy-one.