IMPROVEMENTS IN APPARATUS FOR REGULATING THE ADMISSION OF AIR TO FURNACES
Year: 1857

page_text: LETTERS PATENT to James Petrie, of Rochdale, in the County of Lan-
caster, Engineer, for the Invention of "IMPROVEMENTS IN APPARATUS FOR
REGULATING THE ADMISSION OF AIR TO FURNACES,"
Sealed the 26th February 1858, and dated the 2nd September 1857.
PROVISIONAL SPECIFICATION left by the said James Petrie, at the Office
of the Commissioners of Patents, with his Petition, on the 2nd September
1857.
I, JAMES PETRIE, of Rochdale, in the County of Lancaster, Engineer, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN APPA-
RATUS FOR REGULATING THE ADMISSION OF AIR TO FURNACES," to be as follows:-
My improvements relate, firstly, to the admission of air through the furnace
door or doors, and consist in forming the same with apertures, which are
caused to be closed subsequently to the shutting of the door or doors, and in
such manner that the said closing shall take place at an accelerated rate. A
method I adopt is as follows:-The doors are provided with a series of
parallel openings, and against them is situate a slide, also having openings,
but one edge therecf is formed of a shape. At the commencement there.
fore the point of the slide comes into operation, and subsequently an increasing
area, so as to gain the required accelerated rate of closing. The slide may be
allowed to move upon the shutting of the door by various arrangements, but I
prefer the use of an hydraulic apparatus as now used for a similar purpose,
and another part of my Invention relates to the construction thereof. In the
apparatus alluded to the motion of the slide is resisted by the forcing of water
through an aperture capable of being regulated at pleasure, and this forcing is
effected by means of a piston connected to the said slide. In constructing the
Price 8d1

page_text: piston, I use leather or other expanding packing, and in such manner that
when required to pass through the water without resistance it shall be clear of
the cylinder, so as to permit the fluid to pass freely around it, but when in
motion for the closing of the air passages it is caused to expand and become
tight. The said piston I also construct with valves, to allow the passage of the
fluid at the required time. The cylinder I cast upon or bolt to the door
framing, and connect the piston to the slide by a chain or similar apparatus.
My improvements as above described refer to the admission of air through
the furnace doors, but I also apply them to the admission of air at the bridge
or other part of the furnace.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said James Petric, in the Great Seal Patent Office on the 2nd
March 1858.
TO ALL TO WHOM. THESE PRESENTS SHALL COME, I, JAMES
PETRIE, of Rochdale, in the County of Lancaster, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Second day of September, in the year of our Lord
One thousand eight hundred and fifty-seven, in the twenty-first year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said James Petrie, Her especial license that I, the said James Petrie, my
executors, administrators, and assigns, or such others as I, the said James
Petrie, 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, aud Isle of Man, an Invention for "IMPROVEMENTS IN APPARATUS FOR
REGULATING THE ADMISSION OF AIR TO FURNACES," upon the condition, amongst
others, that 1, the said James Petrie, by an instrument in writing under my
haud and seal, 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 James Petrie, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement and accompanying Drawings (that is to say) :-

page_text: My improvements relate, firstly, to the admission of air through the furnace
door or doors, and consist in forming the same with apertures, which are
caused to be closed subsequently to the shutting of the door or doors, and in
such manner that the said closing shall take place at an accelerated rate.
Another part of my Invention relates to the construction of an hydraulic
apparatus for permitting such closing.
And in order that my Invention may be fully understood, I have appended
to this my Specification a Sheet of Drawings, which I will now proceed to
describe.
Fig. I is an end view of part of a boiler, with the improvements adapted;
Fig. 2 is a cross section thereof; and Fig. 3. a top view. The boiler is shewn
at a, and the furnace door at b, turning upon hinges at c; the door is formed
with parallel openings d, and is at either side furnished with guides e, within
which is situate a sliding plate f; this plate has a corresponding number of
openings g, but instead of being parallel, as those of the door, their uppersides
are formed with two angles, as shewn in the detached view, Fig. 4; to the
sliding plate fis connected a chain h, which passes over a pulley i carried by
the door, from thence over a pulley k mounted upon the fixed door plate, and
its other end is attached to a piston rod of the hydraulic apparatus, for
governing the motion, the internal construction of which I will now describe
by reference to Figs. 5 and 6. A cylinder m is secured to or formed upon
the door plate n; within this cylinder is a piston o, fitted upon the rod 7 and
packed by means of the cupped leather p. Within the piston are formed
openings g, above which is a disc or valve of leather or other elastic material
kept in a central position by means of a thimbles and flange, which passes
into a circular aperture thereof. On one side of the cylinder is a channel t
provided with a tap u, which may be turned so as to allow a quicker or slower
passage of fluid from one side of the piston to the other. The operation is as
follows:-According to the position shewn in the Drawings the door b is
represented as shut, the apertures d closed by the descent of the plate fl, and
the water in the cylinder m beneath the piston. When the door is opened
for the purpose of firing, the turning thereof will bring the pulley i nearer to
that shewn at k, in consequence of which the chain h will become slacker, so
as to allow the piston to descend through the water, which will then lift the
disc or valve and pass through the apertures q. Upon the door being turned
in the act of closing it, the tendency will be to draw the piston upward again
thro' the medium of the chain h, but as the disc or valve r will then close on
the apertures q, and as the fluid cannot escape at a sufficient rate thro' the tap
u, a resistance will take place so as to cause the tightening of the chain to lift

page_text: the sliding plate finto the position shewn at Fig. 7, in which the red lines
denote the parallel openings formed in the door. The plate fis, however, of
sufficient weight to overcome that of the piston o, and to canse the fluid to
pass slowly through the tap u to the under side of the piston; it will therefore
now gradually fall so as to close the openings d, and in so doing the points x
(Fig. 7) will first present themselves thereto, then a more extended surface,
and so on, each vertical space through which the plate passes closing an
increased area, until the position represented at Figs. 1 and 2 is again
attained. The velocity with which the plate descends may be regulated by
turning the tap u, as in other apparatus of this description. In order to pre-
vent the chain from being drawn off the pulley k upon the door being
opened, there is a guide pulley y mounted up a stationary part. I have above
described the plate f as connected with an hydraulic apparatus, but I do not
confine myself to such combination, as other methods may be adopted for
causing it to descend gradually upon the closing of the door. I would also
remark, that for the angular openings thereof a curve or other suitable form
may be substituted, and that a modification thereof may be effected by piercing
the door with the said angular or other the like openings and causing them to
be closed by a straight line upon the plate.
Having thus described and ascertained the nature of my said Invention, and
the manner in which the same is to be performed, I desire it to be under-
stood that I claim as secured to me under the above in part recited Letters
Patent,
Firstly, so constructing the apparatus for the admission of air thro' furnace
doors that the closing of the apertures by which it enters shall take place at
an accellerated rate.
In reference to hydraulic apparatus used for the above purpose, I claim the
circular valve or disc r; also I claim bolting or forming the cylinder upon the
door framing.
In witness whereof, I, the said James Petrie, have hereunto set my hand
and seal, this First day of March, in the year of our Lord One thousand
eight hundred and fifty-eight.
JAMES PETRIE. (L.S.)