IMPROVED APPARATUS FOR HEATING AND ANNEALING METALS
Year: 1853

page_text: LETTERS PATENT to Samuel Colt, of Spring Gardens, in the County
of Middlesex, Gentleman, for the Invention of "IMPROVED APPA-
Sealed the 17th May 1853, and dated the 16th March 1853.
PROVISIONAL SPECIFICATION left by the said Samuel Colt at the
Office of the Commissioners of Patents, with his Petition, on
the 16th March 1853.
I, SAMUEL COLT, do hereby declare the nature of the said Invention
for "IMPROVED APPARATUS FOR HEATING AND ANNEALING METALS" to be
as follows:-
The object of this Invention is to facilitate the cutting and forging of
metals. In order to soften steel, and avoid the risk of its getting burnt
through the inexperience of the operator, I construct my annealing
furnace in such a manner that the attendant is enabled to ascertain, by
inspection, when the metal has attained the required temperature, and
at what time to damp the furnace fire. The metal to be operated upon
is placed in a cast-iron box, and surrounded by charcoal dust, as is usual
in such operations. This box is set in brick-work, and forms the top of

page_text: the fire-place. The flame plays directly upon the bottom of the box,
and passing upwards, when it has arrived at the end thereof it is divided
and directed in two streams along the sides to the front of the box, where
the two streams incet and pass upwards under a cast-iron cover, which
is placed on the top of the box, and forms a flue for conducting the
flame and gases of combustion to the chimney. Fixed in the box,
and extending from end to end thereof, is an iron pipe of about an
inch bore (more or less), and through the front wall of the furnace a
sight hole is made in a line therewith. When the furnace is in opera-
tion, the cover of the box is covered with sand or other material that
will retain or prevent the radiation of heat, and the sight hole is
closed with clay or other suitable substance. From time to time
the attendant removes the clay to inspect the tube; and when, by its
color, it shews that the contents of the box have attained a proper
degree of heat, he damps the fire, and leaves the furnace to cool down
gradually. When the heat is entirely spent, the metal contained in the
box may be removed, and it will then be ready for use. I adopt a
similar plan of keeping the heating operation within sight when heating
metals for forging or welding. For this purpose I sink the fire of the
forge beneath the hearth or plate upon which the rods, bars, or other
pieces of metal to be heated are laid, and I thus have the metal in sight,
lying upon (instead of being inserted in) the fuel. The blast is carried
up from below through the fuel, and the fuel (anthracite), which lies in
a heap or heaps, is so placed that the flame will strike upon it, and heat
it gradually before it is raked into the fire-box, by which means it is
prevented from flying and splitting, and is caused to burn steadily, like
the common coal.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixteenth day of March, in the
year
of our Lord One thousand eight hundred and fifty-three, in the six-
teenth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Samuel Colt, Her special licence
that I, the said Samuel Colt, my executors, administrators, and assigns,
or such others as I, the said Samuel Colt, my executors, administra-
tors, 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, usc, exercise, and vend,
within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVED APPARATUS FOR
HEATING AND ANNEALING METALS," upon the condition (amongst others)
that I, the said Samuel Colt, by an instrument in writing under my
hand and seal, should particularly describe and ascertain the nature
of the said Invention, and in what manner the same was to be per-
formed, 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 I, the said Samuel Colt, do hereby declare
the nature of my said Invention, and in what manuer the same is to be
performed, to be particularly described and ascertained in and by the
following statement, reference being had to the Drawings hereunto
annexed, and to the letters and figures marked thereon (that is to say):
This Invention relates, firstly, to a novel construction of annealing
furnace or oven, by the use of which the softening or annealing of steel
may be carried on without the risk of the metal being injuriously acted
upon by the fire, and the cooling of the metal may be made so gra-
dual as to ensure a good result. The inconvenience of burning
metal, which, according to the ordinary plan of annealing, it is almost
impossible in all cases to avoid, is remedied by enabling the operator
to ascertain by inspection when the metal has attained the required
temperature, and at what time to damp the furnace fire.
In Sheet I., of the accompanying drawings, Fig. 1, is a longitudinal
section of my improved construction of annealing furnace or oven; and

page_text: Fig. 2, is a cross section of the same, taken in the line 1, 2, of Fig. 1.
a, a, are the walls of the furnace, and 6, b, the fire bars; c, c, is a cast-
iron box, which rests on the side walls of the furnace, immediately
above the fire bars, and is intended to receive the metal required to be
annealed. This box is covered by a lid d; and passing from end to
end thereof, and reaching through to the front wall of the furnace, is a
tube c, whose ends are open. The object of this tube is to provide a
sight hole into the box, to enable the attendant to see the progress
of the heating operation. A flue f. f', f³, is made for the passage of
the flame from the fire place along the back, the sides, and the front
of the box c, c.
The flame rises into the flue, at the back of the
box c, and, there dividing, passes along the side flues f', to the flue f
where it ascends into a flue f³, formed of inverted iron troughs or
boxes placed over the box c. This flue f, runs into a brick flue f*,
which leads direct to the chimney. In order to prepare the furnace
or oven for the annealing operation, the box c, is first to be charged
with the steel. For this purpose, the troughs or boxes forming the
flue f, and likewise the lid d, are removed; the bars or rods of steel
are then laid in the box, and embedded in powdered charcoal, or other
like carbonaceous material. When the box is charged, the lid is
placed on the box, and over it are laid the troughs or boxes which
form the return flue of the furnace; the whole is then covered in with
a bed of sand of sufficient depth to ensure a slow radiation of heat
from the upper part of the furnace. The fuel on the fire bars is now
to be lighted, and kept evenly spread over the fire bars, to render
the heat equable all over the bottom of the box c; and the pro-
gress of the heating is to be watched by the attendant, who, by with-
drawing a plug or clay filling from the forward end of the tube e,
may judge of the contents of the box c, by the color of the tube.
When the tube has attained to a cherry red heat, the fire is to be
damped. This is effected by shutting the ash-pit door, and closing a
damper in the flue which leads to the chimney. The furnace is then
left to cool down gradually, and in about three days the heat will have
entirely escaped, and the steel will be found to have been perfectly
annealed.

page_text: This Invention relates, secondly, to the heating of metals to prepare
them for the forging or welding operation, and consists in a novel con-
struction of smith's forge, in which anthracite coal may be employed
with advantage.
In Sheet II. of the drawings, Fig. 1, is a front view of the improved
construction of smith's forge; Fig. 2, is a sectional plan view of the
same; and Fig. 3, is a cross section, taken in the line 1, 2, of Fig. 1.
a, a, is the bearth, made of cast iron, and carried by standards b, b: the
centre of the hearth is sunk to form a fire-place c, which is closed at
bottom by a box d, constituting the ash-pit. The fire-place is provided
with a hinged grating which sustains the fuel, and, when let down to
the dotted position of Fig. 3, will discharge the ashes which have col-
lected upon it. This grating is linked to the hinged bottom of the
box d, and is sustained in a horizontal position by means of a latch d",
with which the box is provided. Into this box a blast pipe e, leading
from a fan or blower, enters for the purpose of supplying the fire with
a blast of air. Above the fire-place, and supported at its four corners,
is a fire-brick f, which deflects the flame, and causes it to spread
laterally. The fire is supplied with anthracite coal, which is laid in
heaps on the hearth a, and is from time to tinie raked into the fire-
place. By the playing of the flame upon the heaps of anthracite the
fuel becomes gradually heated, and thus, when raked into the fire-place,
it is prevented from splitting and flying, and is caused to burn steadily
like common coal. The fuel in the fire-place is retained at about
level with the hearth, and the bars or rods of metal to be heated are
laid thereon (by being passed through the openings g, g,) instead of
being, as is usually the case, thrust into the burning coals. The work-
man will thus always have his metal in sight, which is a great advan-
tage, as he will see when it has attained the requisite heat, and is
ready to be withdrawn from the fire to be further operated upon.
Another advantage consequent on this construction of smith's forge is
that it may be employed by two or more smiths simultaneously, accord-
ing to the number of openings g, g, for the insertion of the metal into
the fire.

page_text: Having now described the nature of my Invention, and the manner
of carrying the same into effect, I wish it to be understood that under
the above in part recited Letters Patent I claim,
First, the construction of annealing furnace or oven, as above
described; and particularly the application of the tube e, to the box
containing the metal to be operated upon, by which means the progress
of the operation may be observed:
And secondly, the construction of smith's forge, as above explained,
whereby anthracite coal may be burned in an open fire, and the metal
to be heated may be kept in sight of the workman.
In witness whereof, I, the said Samuel Colt, have hereunto set
my hand and seal, the Twenty-second day of August, in the
year of our Lord One thousand eight hundred and fifty-three.
Witness present, Eowd. N. DICKERSON,
of New York.
SAM. COLT. (L.S.)