IMPROVEMENTS IN THE. CON- STRUCTION OF FURNACES FOR STEAM BOILERS
Year: 1871

page_text: LETTERS PATENT to Thomas Robinson, of Hebden Bridge, in the
County of York, for the Invention of "IMPROVEMENTS IN THE. CON-
STRUCTION OF FURNACES FOR STEAM BOILERS."
Sealed the 1st December 1871, and dated the 7th October 1871.
PROVISIONAL SPECIFICATION left by the said Thomas Robinson at
the Office of the Commissioners of Patents, with his Petition, on
the 7th October 1871.
I, THOMAS ROBINSON, of Hebden Bridge, in the County of York, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN
THE CONSTRUCTION OF FURNACES FOR STEAM BOILERS," to be as follows :-
The object of this Invention is to effect the more perfect and econo-
mical combustion of the fuel employed, and to prevent the formation of
smoke.
The Invention consists principally in forming a suitable number of
holes through the end plate of the boiler, just above the furnace door,
and providing each hole with a steam jet in the centre to create a
vacuum and induce a current of air to enter with the steam into the

page_text: furnace; and in placing a second bridge in an inverted or hanging
position at about two feet six inches behind the ordinary bridge.
In applying my Invention to an ordinary two-flued boiler, I tap a
short elbow pipe through the end plate of the boiler into the steam
space near the top thereof, and I connect to this elbow pipe two curved
branch pipes (by preference of copper), the ends of which are brought in
a curved form in front of the end plate of the boiler, one just above cach
furnace door. In this portion of the end plate are drilled or otherwise
formed two, three, or more holes (of, say, about two inches diameter),
and into the branch pipe opposite to the centre of each hole is tapped 1
a jet, projecting through the hole in the end plate slightly into the
furnace. It will be evident that upon opening a stop tap in the elbow
pipe a jet of steam will rush in through the centre of each hole into the
furnace, and by creating a vacuum will at the same time draw in a
current of air round the jet, and greatly assist the combustion of the 1
fuel.
Each branch pipe is also provided with a stop-cock, to the lever of
which is connected a sliding door working in front of the air holes, so.
that as the cock is opened the sliding door is opened likewise, and vice.
versa. The sliding door is provided with slots to allow it to work past 2
the steam jets. In each furnace door I employ a revolving ventilating
plate, and I also connect these plates by legs or links to pins on the
sliding doors in such a way that the opening of one shall cause the
opening of the other, and vice versa.
By these means the opening or closing of the tap by a lever will open 2
or close the ventilation in and above the doors, and each furnace can be
worked independently by the other.
"
In making the second or hanging bridge before named, I first form
a single inverted arch by laying a single row of bricks across the lower
part of the flue, the ends of the said arch being about level with the 3
centre of the flue, and then, using the ends of this inverted arch as
abutments, I construct thereon a flat arch of fire-brick across the flue,
and then proceed to fill in the space above this arch solid with fire-
brick, and I thus get an inverted or hanging bridge with an open space
beneath.
3

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Thomas Robinson in the Great Seal Patent Office
on the 6th April 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
ROBINSON, of Hebden Bridge, in the County of York, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventh day of October, in the year of
our Lord One thousand eight hundred and seventy-one, in the thirty-
fifth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Thomas Robinson, Her special license that I,
the said Thomas Robinson, my executors, administrators, and assigns, or
such others as I, the said Thomas Robinson, 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 THE CONSTRUCTION OF
FURNACES FOR STEAM BOILERS," upon the condition (amongst others) that
I, the said Thomas Robinson, 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 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 Thomas Robinson, 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 and accompanying Drawings (that is to say):-
The object of this Invention is to effect the more perfect and econo-
mical combustion of the fuel employed, and to prevent the formation of
smoke.
The Invention consists principally in forming a suitable number of
holes through the end plate of the boiler, just above the furnace door,
and providing cach hole with a steam jet in the centre to create a

page_text: vacuum and induce a current of air to enter with the steam into the
furnace; and in placing a second bridge in an inverted or hanging
position at about two feet six inches behind the ordinary bridge.
In applying my Invention to an ordinary two-flued boiler, I tap a
short elbow pipe through the end plate of the boiler into the steam
space near the top thereof, and I connect to this elbow pipe two curved
branch pipes (by preference of copper), the ends of which are brought in
a curved form in front of the end plate of the boiler, one just above each
furnace door. In this portion of the end plate are drilled or otherwise
formed two, three, or more holes (of, say, about two inches diameter),
and into the branch pipe opposite to the centre of cach hole is tapped
a jet projecting through the hole in the end plate slightly into the
furnace. It will be evident that upon opening a stop tap in the elbow
pipe a jet of steam will rush in through the centre of each hole into
the furnace, and by creating a vacuum will at the same time draw in a
current of air round the jet, and greatly assist the combustion of the
fuel.
Each branch pipe is also provided with a stop cock, to the lever of
which is connected a sliding door working in front of the air holes, so
that as the cock is opened the sliding door is opened likewise, and vice
versa. The sliding door is provided with slots to allow it to work past
the steam jets. In each furnace door I employ a revolving ventilating
plate, and I also connect these plates by legs or links to pins on the
sliding doors in such a way that the opening of one shall cause the
opening of the other, and vice versa.
By these means the opening or closing of the tap by a lever will open
or close the ventilators in and above the doors, and each furnace can be
worked independently of the other.
In making the second or hanging bridge before named, I first form
a single inverted arch by laying a single row of bricks across the lower
part of the flue, the ends of the said arch being about level with the
centre of the flue, and then, using the ends of this inverted arch as
abutments, I construct thereon a flat arch of fire-brick across the flue,
and then proceed to fill in the space above this arch solid with fire-
brick, and I thus get an inverted or hanging bridge with an open space
beneath.

page_text: Such being the nature and object of my said Invention for "Improve-
ments in the Construction of Furnaces for Steam Boilers," I will now
proceed to describe more in detail the manner in which the same is to bo
or may be performed or carried into practical effect; and in order that
the same may be clearly understood, I have annexed hereunto a Sheet of
Drawings illustrative thereof, and have marked the same with figures
and letters of reference corresponding with those in the following expla-
nation thereof :-
Fig. 1 in the annexed Drawing represents an end elevation of a two-
flued steam boiler, with my Invention shown as applied thereto; Fig. 2
is a longitudinal section of the furnace end of the same; and Fig. 3 a
transverse section of the flue, showing the construction of the inverted
or hanging bridge.
a, a, is the cylindrical shell of the boiler; b, b, the end plate, and c, c,
the flues; d, d, are fire-bars; e, e, the ordinary bridge, and f, f, the
hanging bridge, the construction of which latter as above described is
shown clearly at Fig. 3. In the end plate b, b, just above each furnace
door, g, g, are formed a suitable. number of holes (four over each door
are shown in the Drawing), in each of which is fixed a short tube h, h,
(Fig. 2), through the centre of which passes a small steam jet i, i, these
said jets being fixed in the curved branch tubes k, k, connected to the
short elbow pipe 1, 1, which is tapped through the end plate of the boiler
into the steam space. The elbow pipe is provided with a stop tap or
valve m, m, and the branch pipes are also similarly furnished with stop
taps n, n, the levers of which are connected by links o, o, to sliding
plates or doors p, p, working in front of the air holes above the furnace
doors, so that the opening or closing of the taps n, n; will also by their
levers open or close the sliding plates p, p, the said plates being pro-
vided with slots q, q, to allow them to work past the steam jets. The
furnace doors 9, 9, are also provided with revolving ventilating
plates r, r, connected to the sliding plates p, p, by links 8, 8, so that
the action of the levers of the taps n, n, will also open and close the
said revolving plates r, r, the links 8, 8, being slotted so that the
revolving ventilating plates will not be acted upon in either direction
till the sliding plates have moved a certain distance.
I would here observe that the closing movement of the taps, sliding
plates, and ventilators might easily be made self-acting, so as to shut
off the steam and air automatically in a given time after opening by

page_text: connecting the tap lever to the plunger of a small force pump, which
when the tap is opened forces a certain amount of water or other fluid
into a cylinder, and raises a weighted piston. The said fluid then
escapes slowly through a small orifice, and as it escapes the weighted
piston follows, and closes the taps and air slides.
5
Having now described the nature and object of the said Invention for
Improvements in the Construction of Furnaces for Steam Boilers,"
together with the manner in which the same is to be or may be per-
formed or carried into practical effect, I wish it to be understood that I
claim as my Invention the improvements as herein-before set forth and 1
illustrated by the annexed Drawings, and more especially I claim the
use of the air holes having steam jets in the centre thereof formed in
the end plate of the boiler above the furnace doors, together with the
appliances for opening and closing the same, or any mere modifications
or imitation thereof, constructed and operating in substantially the same 1
or a similar manner.
In witness whereof, I, the said Thomas Robinson, have hereunto set
my hand and seal, this Third day of April, in the year of our Lord
One thousand eight hundred and seventy-two.
Witnessed by
GEORGE DAVIES, C.E.,
Patent Agent,
Manchester.
THOMAS ROBINSON. (L.S.)