IMPROVEMENTS IN BLAST FURNACES
Year: 1868

page_text: LETTERS PATENT to Henry Cochrane, of the Longlands, Middles-
borough-on-Tees, in the County of York, for the Invention of
"IMPROVEMENTS IN BLAST FURNACES."
Scaled the 2nd October 1868, and dated the 4th April 1868.
PROVISIONAL SPECIFICATION left by the said Henry Cochrane at
the Office of the Commissioners of Patents, with his Petition, on
the 4th April 1868.
I, HENRY COCHRANE, of the Longlands, Middlesborough-on-Tees, in
the County of York, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN BLAST FURNACES," to be as follows:-
My improvements have reference to close-topped blast furnaces,
and consists in an arrangement whereby while the top is effectually
closed against the escape of the combustible gas, the danger of injury
arising from explosions is obviated, and the materials are charged
into the furnace in a more effectual manner and with a less escape
of gas than heretofore. For this purpose I enclose the top of the
furnace with a flat covering plate having centrally an explosion valve

page_text: of large dimensions, fitting with
sand lute into an annular trough
formed round the edge of the opening in the covering plate. The
valve when lifted by the pressure of gas from below is guided in its
motion by means of upright guides, between which projections on the
.valve fit, so that when it drops it will fall correctly in its place in
the trough again. In the centre of this large valve I form by pre-
ference a small valve also fitting in a trough with a sand lute, and
connected to a hand lover in such a manner that it can be lifted
off and moved to one side when the metal is being run out of the
furnace. Round the explosion valve I arrange a series of hoppers
sunk below the level of the covering plate and projecting slightly
above the same, where they are provided with covers hinged at the
back and having a balance weight attached thereto, either directly
or by means of a chain passing over a pulley on a standard, for the
facility of opening them and keeping them open when the materials
require to be charged into the hoppers. These hoppers communicate
at their lower ends with the interior of the blast furnace by means of
openings provided with hinged doors arranged with balance weights
and with catches so as to close of themselves and keep closed, unless
they are purposely opened by releasing the catches when the hoppers
contain a charge of materials to be introduced into the furnace, which
materials then force the doors open by their weight. The releasing
of the catches is effected by means of a lever projecting above the
covering plate, actuating a spindle carrying one or more arms connected
to the releasing catches by links. The lever furthermore actuates an
arm, which in the event of the door not readily opening by the pressure
of the materials, presses against the door and forces it open. To
prevent injury to the trucks in tipping against the side of the
hoppers, these are furnished with sloping ledges or shelves at their
mouths, upon which the angle iron at the back of the trucks rests
when these are tipped. A wooden sill is also placed against the pro-
jecting edge of the hopper to prevent the wheels from striking against
the same. The before-mentioned levers and spindles actuating the
doors of the hoppers are enclosed so as not to be injured by the
materials charged in, and the doors are so arranged as to be readily
removed in case of injury and replaced through closed openings in
the covering plate. They may be constructed either to open towards the
centre of the furnace or towards the side of the same. If arranged in
a nearly vertical position in the side of the hopper, slightly inclined

page_text: in such a direction as to close by their own weight, the doors may
be employed without balance weights. In some cases also, in place
of arranging the doors of the hoppers to open on hinges, they may
be made to slide up and down in grooves similar to a slide valve. In
operating with these hoppers, when the materials have been tipped into
them, the covers are closed down and then the lower doors are opened
by means of the levers as described, so as to let the charge fall into
the furnace. By this arrangement the only loss of gas will be that
which passes into the hoppers while the charge is passing from the
same into the furnace.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Henry Cochrane in the Great Seal Patent Office on
the 2nd October 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
COCHRANE, of the Longlands, Middlesborough-on-Tecs, in the County of
York, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patcut, bearing date the Fourth day of April, in the year of
our Lord One thousand eight hundred and sixty-eight, in the thirty-
first year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Henry Cochranc, Her special licence
that I, the said Henry Cochrane, my executors, administrators, and
assigns, or such others as I, the said Henry Cochrane, my executors,
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 BLAST FURNACES," upon the condition (amongst others) that I, the said
Henry Cochrane, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands. and seals, should
particularly describe and ascertain the nature of the said Invention,
and in what manner the same was to be performed, and cause the

page_text: 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 Henry Cockranc, do hereby declare
the nature of the said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and
by the following statement thereof, reference being had to the accom-
panying Drawings, and to the figures and letters marked thereon, that is
to say:-
My improvements have reference to close-topped blast furnaces, and
consist in an arrangement wherchy while the top is effectually closed
against the escape of the combustible gas, the danger of injury arising
from explosion is obviated, and the materials are charged into the
furnace in a more effectual manner and with a less escape of gas
than heretofore. For this purpose I enclose the top of the furnace
with a flat covering plate having centrally an explosion valve of
large dimensions, fitting with a sand lute into an annular trough
formed round the edge of the opening in the covering plate. The
valve when lifted by the pressure of gas from below is guided in
its motion by means of upright guides, between which projections
on the valve fit, so that when it drops it will fall correctly in its
place in the trough again. In the centre of this large valve I form
by preference a small valve also fitting in a trough with a sand lute,
and connected to a hand lever in such a manner that it can be
lifted off and moved to one side when the metal is being run out of
the furnace. Round the explosion valve I arrange a series of hoppers
sunk below the level of the covering plate and projecting slightly
above the same, where they are provided with covers hinged at the
back and having a balance weight attached thereto, either directly
or by means of a chain passing over a pulley on a standard, for the
facility of opening them and keeping them open when the materials
require to be charged into the hoppers. These hoppers communicate
at their lower ends with the interior of the blast furnace by means
of openings provided with hinged doors arranged with balance weights
and with catches so as to close of themselves and keep closed, unless
they are purposely opened by releasing the catches when the hoppers
contain a charge of materials to be introduced into the furnace, which
materials then force the doors open by their weight: The releasing

page_text: of the catches is effected by means of a lever projecting above the
covering plate actuating a spindle carrying one or more arms connected
to the releasing catches by links. The lever furthermore actuates
an arm, which in the event of the door not readily opening by the
pressure of the materials presses against the door and forces it open.
To prevent injury to the trucks in tipping against the sides of the
hoppers, these are furnished with sloping ledges or shelves at their
mouths, upon which the angle iron at the back of the trucks rests
when these are tipped. A wooden sill is also placed against the
projecting edge of the hopper to prevent the wheels from striking
against the same. The before-mentioned levers and spindles actuating
the doors of the hoppers are enclosed so as not to be injured by the
materials charged in, and the doors are so arranged as to be readily
removed in case of injury, and replaced through closed openings in
the covering plate. They may be constructed either to open towards
the centre of the furnace or towards the side of the same. If arranged
in a nearly vertical position in the side of the hopper, slightly inclined
in such a direction as to close by their own weight, the doors may
be employed without balance weights. In some cases also, in place
of arranging the doors of the hoppers to open on hinges, they may be
made to slide up and down in grooves similar to a slide valve. In
operating with these hoppers, when the materials have been tipped
into then the covers are closed down, and then the lower doors are
opened by means of the levers as described, so as to let the charge
fall into the furnace. By this arrangement the only loss of gas will
be that which passes into the hoppers while the charge is passing
from the same into the furnace.
Having thus set forth the nature of my Invention, I will now proceed
more particularly to described the manner of performing the same, for
which purpose I will refer to the accompanying Drawings, which show
some of the various arrangements by which my Invention may be
carried into effect.
Figures 1 and 2, on Sheet I., show one arrangement. Figure 1 shows a
part sectional elevation of the top of the blast furnace with my improve
apparatus applied thereto, and Figure 2 shows a part plan of the same.
The top of the blast furnace A is covered with a floor plate B, having
a central opening C, round which is formed an annular trough D. Into

page_text: this trough the explosion valve or cover E fits with a sand lute, which
valve on the occasion of an explosion of gas in the furnace is lifted up
thereby, thus preventing any injury to the furnace. The valve is guided
during such motion by the guides F in such manner as afterwards to fall
correctly into its place in the sand trough D. In the centre of this valve
is formed an aperture G, closed by means of a cover I also fitting into
a sand trough I, and which is raised by means of the lever J when the
metal is run off from the furnace below. At four opposite points of the
top of the blast furnace are formed the hoppers or receptacles K for
receiving the materials to be introduced into the furnace. These hoppers
project slightly above the floor plate B, as shown, and are provided with
covers L hinged to the back thereof, and provided with balance weights M,
whereby they are kept open when required. At the lower end of cach
hopper is an opening provided with a door N, through which it com-
municates with the interior of the furnace. The door N is hinged to the
hopper at O, and is provided with a weighted arm P, which tends to keep
the door in the closed position. The door is also held in this position
by means of the catches Q on each side of the hopper taking into cor-
responding catches R fixed on the door. The catches Q arc made so as
to fall into the catches R by gravity as soon as the door is closed by the
weighted arm P; they are connected by means of the levers S and
links T to the spindle U passing across the hopper, to one end of which
spindle is attached the lever V, whereby the catches Q are released when
the door N requires to be opened. On the spindle U is furthermore an
arm W, so arranged as by the motion of the lever V to press against the
door N and push it open should anything prevent it from being opened
readily by the pressure of the materials in the hopper. The catches and
levers, as also the spindle U, arc all covered in, as shown, so as not to be
injured or clogged by the materials in the hopper. In operating with
this apparatus the door N being closed the lid L is opened, and the
materials are tipped into the hopper K by the truck X, ledges Y being
formed on the sides of the hopper for the truck to rest on, and a wooden
sill Z being placed against the front edge of the hopper to prevent injury
to the wheels. The materials having been filled into the hopper the
lid L is closed down, and the lever V is moved so as to release the
catches Q, when the door N will be forced open by the materials, which
will then fall into the furnace. As soon as the hopper is emptied the
door N will be closed by the weighted arm P ready for another charge.

page_text: By this arrangement it will be evident that the only quantity of gas that
can escape during the process of charging is that which passes into the
hopper while the materials are falling into the furnace. The door N is
arranged to be dropped into its place through a closed opening formed
directly above it in the floor plate B.
Figures 3 and 4, ou Sheet II. of the Drawings, show respectively a part
sectional clevation and part sectional plan of another modification of the
apparatus. In this arrangement the side of the hopper in which the
lower opening is formed is made nearly vertical, so that the door N when
closed is slightly inclined in the opposite direction to that of the door in
the first arrangement, whereby it has a tendency to close of itself, and
does not require the assistance of the weighted arm described in the first
arrangement for effecting this purpose; the door is in this case held by
two catches Q, Q, on each side instead of only one as before. The other
parts of the apparatus are the same as in the fiist-described arrangement,
and are designated by the same letters of reference. The central opening
and cover to the explosion valve E is omitted in this arrangement.
Figures 5 and 6, on Sheet III. of the Drawings, show respectively a
part sectional elevation and part sectional plan of a third modification of
the apparatus. In this arrangement the doors N to the hoppers, in place
of opening towards the centre of the furnace as in the two previous
arrangements, are made to open towards the sides thereof. The other
parts are the same as in the previous arrangements with the exception of
the lid L being connected to a balance weight M by means of a chain L'
passing over a pulley M' carried by the standards M², in place of the
weighted arm in the previous arrangements.
Having thus described the nature of my Invention, and in what
manner the same is to be performed, I wish it to be understood that I do
not limit myself to the precise arrangements thereof shown on the accom-
panying Drawings, as these may be variously modified without departing
from the nature of my Invention; but what I claim is,―
First. The employment of lateral charging hoppers or receptacles sunk
into the tops of blast furnaces, and provided with doors to their lower
apertures and with covers to their upper openings, the said doors to

page_text: the lower apertures being held by catches or equivalent appliances
actuated by means of levers from the top of the furnaces, the whole
operating substantially in manner and for the purposes herein-before
set forth.
Second. Arranging a number of such before described hoppers round
a central explosion valve, substantially as herein-before described.
Third. I claim in combination the general arrangement of apparatus
for feeding blast furnaces. herein-before described with reference to the
accompanying Drawings."
In witness whereof, I, the said Henry Cochrane, have hereunto 1
set my hand and scal, this Twenty-fourth day of September,
in the year of our Lord One thousand eight hundred and
sixty-eight.