NEW OR IMPROVED FURNACES FOR HEATING, REHEATING, TEMPERING, OR OTHERWISE TREATING IRON, STEEL, OR OTHER METALS." PROAL SPATION
Year: 1874

page_text: LETTERS PATENT to John Robertson, of Nitshill, in the County of
Renfrew, North Britain, Engineer, for the Invention of "NEW OR
IMPROVED FURNACES FOR HEATING, REHEATING, TEMPERING, OR OTHERWISE
TREATING IRON, STEEL, OR OTHER METALS."
PROVISIONAL SPECIFICATION left by the said John Robertson at
the Office of the Commissioners of Patents, with his Petition, on
the 20th May 1874.
I, JOHN ROBERTSON, of Nitshill, in the County of Renfrew, North
Britain, Engineer, do hereby declare the nature of the said Inventiou
of "NEW OR IMPROVED FURNACES FOR HEATING, REHEATING, TEMPERING, OR
OTHERWISE TREATING IRON, STEEL, OR OTHER METALS," to be as follows, that is

page_text: steel, or other metals, consists of a chamber provided with holes at
one or more of its sides or ends, through which the bars, plates, or other
forms of iron, steel, or other metals to be heated, reheated, tempered, or
otherwise treated by heat are passed into the chamber. The heat in the
chamber is produced by the combustion of air or oxygen and coal gas, or
hydrocarbon vapour mixed or combined under pressure before issuing
from the orifices whereat it is burned. .
In practice it is found convenient to form the top or roof of the furnace
with a small channel or chamber, from which tubular openings diverge
over the roof, and through which numerous jets of the air and gas mixed
or combined under pressure issue.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Robertson in the Great Seal Patent Office 1
on the 19th November 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
ROBERTSON, of Nitshill, in the County of Renfrew, North Britain,
Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twentieth day of May, in the year of
our Lord One thousand eight hundred and seventy-four, in the
37th year of Her reign, did, for Herself, Her heirs. and successors,
give and grant unto me, the said John Robertson, Her special license
that I, the said John Robertson, my executors, administrators, and
assigns, or such others as I, the said John Robertson, my executors,
administrators, or 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 " NEW OR IMPROVED FURNACES
FOR HEATING, REHEATING, OR OTHERWISE TREATING IRON, STEEL, OR OTHER

page_text: METALS," upon the condition (amongst others) that I, the said John
Robertson, by an instrument in writing under my hand and scal, 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 I, the said John Robertson, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement, reference being had to the accompanying Drawings
and to the letters and figures marked thereon, that is to say: —
My said Invention relates to new or improved furnaces to be used for
heating, reheating, tempering, or otherwise treating by heat, iron, steel,
or other metals, and in which the degree of heat necessary to perform
these operations is produced by the combustion of air or oxygen and coal
gas or hydrocarbon vapour mixed or combined under pressure before
issuing from the orifices whereat the mixture is inflamed or burned.
And in order that my said Invention may be properly understood I
now proceed more particularly to set forth the system, mode, or manner
in or under which the same is or may be used or practically carried into
effect, reference being had to the annexed Sheet of Drawings and to the
letters and figures marked thereon, that is to say :-
On the Sheet of Drawings hereunto appended Figure 1 is a side
elevation of the new or improved furnace constructed in accordance with
my said Invention; Figure 2 is a plan thereof; Figure 3, an end eleva-
tion; and Figure 4, a horizontal section of the same on the line a, b,
Figure 1.
As shewn by these Figures the furnace is situated on a standard or
framing A. The furnace is constituted of a slab or block B of fire-clay
or other refractory material. On the upper side of the slab or block B a
chamber or space C, open at both ends of the block, is formed, which
space constitutes the heating or tempering chamber of the furnace. On
the slab or block B another slab or block D of fire-clay or other refrac-
tory material is placed so as to form the roof or crown of the chamber C,
between which chamber and a chamber E formed on the upper side of

page_text: the block D communication is effected by numerous small passages or
perforations, as indicated by the dotted lines at x, Figures 1 and 3. The
blocks or slabs B and D are bound or held together by a metal plate F,
which covers the chamber E, and by tie bars G, passed through arms or
projections c on the plate F, and also through lugs d formed on the
standard or framing A. A luting of clay or other similarly suitable
substance may also, if desired, be used at the junction of the blocks B
and D in order to ensure the said joints being air tight. In the furnace
illustrated on the Drawings the open ends of the chamber C are closed
or covered by metal plates H held in position by tie bars I, and through
the said plates holes e are made, as shewn at Figures 3 and 4, for the intro-
duction of the iron, steel, or other metal to be treated into the chamber C..
The said plates H may however be dispensed with, and one or both ends
of the chamber left open.
The chamber C is preferably made deeper at its central portion than
at the ends, as indicated in dotted lines at Figure 1, and in the said sunk
portion broken fire-brick, chalk, or other refractory material is placed in
order to effect a better diffusion of the heat.
The coal gas or hydrocarbon vapour and air or oxygen (by the com-
bustion of which the furnace is heated) are conducted through separate
pipes J and K into a pipe L, wherein they are admixed under pressure,
and thereafter pass together into the chamber or channel E, and thence
through the perforations or passages x to the chamber C, wherein the
mixture is ignited and burned, thereby heating the chamber and the
iron, steel, and other metal contained therein. The proportions of gas
and air relatively with each other, and also the degree of heat within the
chamber C is regulated by providing the pipes J and K with cocks or
valves, as shewn on the Drawings.
Having now described and particularly ascertained the nature of my
said Invention, and the system, mode, or manner in or under which
the same is or may be used or practically carried into effect, I would
observe in conclusion that what I consider to be novel and original, and
therefore claim as the Invention secured to me by the herein-before in
part recited Letters Patent is, the arrangement and construction of
furnaces heated by the combustion of air or oxygen and coal gas, or the
vapour of hydrocarbon mixed or combined under pressure before issuing

page_text: from the burners, and the employment of such furnaces as and for the
purposes herein-before described.
In witness whereof, I, the said John Robertson, have hereunto set
my hand and seal, this Seventeenth day of November, One
thousand eight hundred and seventy-four.