IMPROVEMENTS IN FURNACE DOORS AND IN APPARATUS CONNECTED THEREWITH
Year: 1870

page_text: LETTERS PATENT to David Auld, the younger, of Glasgow, in the
County of Lanark, North Britain, Engineer, for the Invention
of "IMPROVEMENTS IN FURNACE DOORS AND IN APPARATUS CONNECTED
THEREWITH."
Sealed the 27th June 1871, and dated the 28th December 1870.
PROVISIONAL SPECIFICATION left by the said David Auld at the
Office of the Commissioners of Patents, with his Petition, on the
28th December 1870.
I, DAVID Auld, the younger, of Glasgow, in the County of Lanark,
5 North Britain, Engineer, do hereby declare the nature of the said In-
vention of "IMPROVEMENTS IN FURNACE DOORS AND IN APPARATUS CONNECTED
THEREWITH," to be as follows, that is to say:-
This Invention, which relates to certain improvements in the doors
of furnaces which are adapted for regulating the supply of air for burning
O the products of combustion in the said furnaces, and thereby practically
prevent smoke, consists in the application of a mechanical device for

page_text: effecting the self-acting opening of the sand box regulator during the
time that the furnace door itself is opened. This is effected by coupling
the crank on the axis of the sand box to a rod passing through a guide
on the door at its lower extremity, the said lower extremity being formed
with a loop or bearing, which as the furnace door is opened slides up an
inclined plane, and therefore becomes lifted to the extent necessary for
turning the crank through a sufficient arc to invert the position of the
sand box, in order that the sand therein may be thrown into the hopper
at the upper side. It is to be understood that in place of arranging the
coupling rod and inclined plane herein-before referred to at the lower
side of the furnace door they may be arranged on the upper side or at
other convenient part thereof.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said David Auld in the Great Seal Patent Office on
the 27th June 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, DAVID
AULD, the younger, of Glasgow, in the County of Lanark, North
Britain, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-eighth day of December, in the
year of our Lord One thousand eight hundred and seventy, in the 34th
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said David Auld, the younger, Her special license
that I, the said David Auld, the younger, my executors, administrators,
and assigns, or such others as I, the said David Auld, the younger,
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
"IMPROVEMENTS IN FURNACE DOORS AND IN APPARATUS CONNECTED THEREWITH,"
upon the condition (amongst others) that I, the said David Auld, the
younger, 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 performed, and cause the same

page_text: 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 David Auld, the younger, 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, which relates to certain improvements in the doors
of furnaces which are adapted for regulating the supply of air for
burning the gaseous products of combustion in the said furnaces and
thereby practically preventing smoke, consists in the application of a
mechanical device for effecting the self-acting opening of the sand box
regulator during the time that the furnace door itself is opened. This is
effected by coupling the crank on the axis of the sand box to a rod
passing through a guide on the door at its lower extremity, the said
lower extremity being formed with a loop or bearing, which as the
furnace door is opened slides up an inclined plane, and therefore becomes
lifted to the extent necessary for turning the crank through a sufficient
arc to invert the position of the sand box in order that the sand therein
be thrown into the hopper at the
side.
upper
It is to be understood that in place of arranging the coupling rod and
inclined plane hercin-before referred to at the lower side of the furnace
door they may be arranged on the upper side or at other convenient part
may
thereof.
And in order that my said Invention may be properly understood
I now proceed to set forth two systems or arrangements in or under
which the same is or may be used or practically carried into effect, and
for the sake of more complete elucidation I have hereunto appended an
explanatory Sheet of Drawings, on which Figure 1 represents a front
elevation of a furnace door adapted for regulating the supply of air for
burning the gaseous products of combustion in the furnace to which it is
attached and showing one modification of my said Invention whereby
the regulator B is constituted self-acting applied thereto; Figure 2
represents an elevation of that end of the door marked A in Figure 1,
whilst Figure 3 is a plan of the same. On these three Figures the
apparatus is shewn in the position which it occupies when the door A
is shut.

page_text: 1
Figure 4 is an elevation of that end of the door marked B, Figure 1,
and shews the position of the apparatus when the door A is open. The
air regulator B is furnished with a sand box C, and on one end of the
axis D of the air regulator and sand box a crank E is fixed to the
pin a, of which the upper end of a rod F is coupled. The rod F passes
down through a guide G fixed to the lower part of the door A, and its
lower extremity is formed to carry, by preference, a roller H, which
revolves on a pin or stud b. The periphery of the roller H, bears upon
an inclined plane I, as shewn, and as the door is being opened the
roller H revolves or rolls up the inclined plane I, thereby pushing the
rod F upwards and turning the crank E, through a sufficient arc to
invert the air regulator B as shown at Figure 4. When the air
regulator B has been thus inverted the sand in the lower part of the
box C falls into the hopper J, situated at the upper end of the box, as
more particularly seen at Figure 1 so that on again shutting the door A,
there is a sufficient weight of sand in the hopper J. to keep the air re-
gulator B open in the position shown in dotted lines at Figure 2. The
hopper J is provided with an opening c at its lower end through which
the sand (on the door being shut) falls slowly back into the lower part
of the box C, and thereby gradually closes the air regulator B. By this
means the regulator B is kept open for a length of time sufficient to
admit the quantity of air requisite to burn the smoke and gaseous
products evolved from the charging of "green" coal into the furnace.
In lieu of arranging the coupling rod F, guide G, and inclined plane I,
herein-before described at the lower side of the furnace door, as shown
at Figures 1, 2, 3, and 4 of the Drawings, the said rod F, guide G, and
inclined plane I may be arranged at the upper side of the furnace door
as shown in front elevation at Figure 5 and in end elevation at Figure 6
of the Drawings, or they may be arranged at other convenient part
thereof, and in place of providing the rod F with a roller H as shown on
the several Figures of the appended Drawings the rod F may be formed
with a loop which as the furnace door is opened slides up the inclined
plane I, and thereby raising the rod F inverts the air regulator B, through
the intervention of the crank E as herein-before described.
Having now described the nature of my said Invention, and two
arrangements in or under which it is or may be used or carried into
practice, I would observe in conclusion that although I have hercin
fully described the sand box regulator B, the sand regulator forms no

page_text: part of this Invention, but what I consider novel and original, and
therefore claim as the Invention secured to me by the herein-before in
part recited Letters Patent is, the apparatus whereby the sand box
regulator B is constituted self-acting, namely, the arrangement of rod F,
and roller H, or its equivalent, and the inclined plane I as herein-before
described and shown on the several Figures of the appended Sheet of
Drawings or any mere modification thereof.
In witness whereof, I, the said David Auld, the younger, have
hereunto set my hand and seal, this Twenty-third day of Junc,
One thousand eight hundred and seventy-one.
DAVID AULD, JUNIOR. (L.S.)