IMPROVEMENTS IN FURNACES AND FURNACE DOORS
Year: 1878

page_text: LETTERS PATENT to Joseph Sawyer, of Alma Street, New North Road, in the
County of Middlesex, Engineer, for--the Invention of "IMPROVEMENTS IN
FURNACES AND FURNACE DOORS."
aled the 16th July 1878, and dated the 9th February 1878.
PROVISIONAL SPECIFICATION left by the said Joseph Sawyer at the Office
of the Commissioners of Patents on the 9th February 1878.
JOSEPH SAWYER, of Alma Street, New North Road, in the County of Middlesex,
Engineer. "IMPROVEMENTS IN FURNACES AND FURNACE DOORS."
This Invention relates,-
Firstly. To improvements on my former Letters Patent, No. 2894, dated the
Seventeenth day of August, One thousand eight hundred and seventy-five.
Secondly. To an improved construction of furnace door and mechanism connected
therewith for automatically closing a slide or valve with which the door is pro-
vided, as herein-after described.
My improvements on the said former Letters Patent consist in forming the
upper surfaces of the furnace bars with semicircular projections; and for communi-
cating motion to the said bars I provide two rocking front bearing bars, connected
together and operated by a lever handle which causes them to rock in opposite
directions; half the number of bars are connected to one of these rocking bars and
the other half to the other rocking bar, by which means, if the said lever handle
be operated, the bars will have a to-and-fro motion communicated to them, each
alternate bar moving in the opposite direction to the remainder, thereby clearing
or breaking up by means of the semicircular projections the clinkers and scoria,
and effecting a more perfect combustion of the fuel by keeping free the air spaces
between the bars.
My improvements in furnace doors consist in providing the door with a vertical
slide or valve, provided with a counterbalanced weight, in such a manner that if
it is desired to open the slide or valve the weight is pulled down and raises the'
slide and keeps it raised, the reverse motion of the weight closing the slide..
:

page_text: For the automatic closing of this slide, after it has remained opened a certain
time, I provide a rectangular shaped case, rotating on a pivot or centre above the
door; in each end of this case slides a conical box or hopper, the inner or smaller
ends of these boxes being open and connected together telescope wise. One of these
boxes is provided with a quantity of sand, ground barytes, or other suitable granular
material. If the slide be now opened, and the rotating case be placed in a vertical
position with the box containing the sand or other material upwards, the sand will
pass therefrom into the lower box and will cause the same to descend and close the
slide. The slide having been again opened when required the case is turned half a
revolution, so as to bring the charged box upwards and again close the slide by
the descent of the other box.
A lever on the latch of the door is connected to the counterweight, so that the
raising of the latch when the door is opened or closed shuts the slide.
The inside or back of the furnace door is provided with a jacket or casing open
at the lower part only, so that the air entering when the slide is open has first to
pass upwards, then downwards, and out through the bottom opening in the said
jacket.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Joseph Sawyer in the Great Seal Patent Office on the 9th
August 1878.
JOSEPH SAWYER, of Alma Street, New North Road, in the County of Middlesex,
Engineer. "IMPROVEMENTS IN FURNACES AND FURNACE DOORS."
This Invention relates,-
Firstly. To improvements on my former Letters Patent, No. 2894, dated the
Seventeenth day of August, One thousand eight hundred and seventy-five.
Secondly. To an improved construction of furnace door and mechanism con-
nected therewith for automatically closing a slide or valve with which the door is
provided, as herein-after described.
My improvements on the said former Letters Patent consist in forming the upper
surfaces of the furnace bars with semicircular projections, and for communicating
motion to the said bars I provide two rocking front bearing bars, connected together
and operated by a lever handle, which causes them to rock in opposite directions;
the bars are connected alternately to one of these rocking bars, by which means.
if the said lever handle be operated the bars will have a to-and-fro motion com-
municated to them, each alternate bar moving in the opposite direction to the
remainder, thereby clearing or breaking up by means of the semicircular projections
the clinkers and scoria, and effecting a more perfect combustion of the fuel by
keeping free the air spaces between the bars.
My improvements in furnace doors consist in providing the door with a slide or
valve, provided with a counterbalanced weight, in such a manner that if it is
desired to open the slide or valve the weight is pulled down and raises the slide
and keeps it raised, the reverse motion of the weight closing the slide,

page_text: For the automatic closing of this slide, after it has remained open a certain time,
I provide a rectangular shaped case rotating on a pivot or centre above or on the
door. This box is divided by conical divisions and is provided with a quantity of
sand, ground barytes, or other suitable granular material. If the slide be now
opened, and the rotating case be placed in an oblique position with the sand or
other material upwards, the sand will pass therefrom into the lower part, causing
it to partly rotate and close the slide. The slide having been again opened when
required the case is turned half a revolution, so as to bring the charged part
upwards, and again close the slide by the descent of the sand.
The inside or back of the furnace door is provided with a jacket or casing, open
at the lower part only, so that the air entering when the slide is open has first to
pass upwards, then downwards, and out through the bottom opening in the said
jacket on to the dead plate, and thus becomes thoroughly heated.
But to make my Invention better understood I will proceed to describe the same,
by reference to the accompanying Drawing in which,-
Figure 1 is a longitudinal section, shewing my improvements in furnaces applied
to an ordinary Cornish boiler; Figure 2, side elevation; and Figure 4, front
elevation of the same.
Figure 3, plan of the fire-grate; and Figure 5, vertical section of the box for
automatically closing the valve.
a, a, a, a¹, are the furnace bars formed with semicircular projections 6 on their
upper surfaces, as shewn in Figure 1; c, c¹, are the two rocking front bearing bars,
connected and working together by the tooth d; e is the lever handle for operating
the said rocking bars; the bars a are connected to and operated by the rocking
bar c by means of the projections f, taking into recesses in the under side of the
front ends of the bars, the remaining bars a¹ being connected with the rocking
bar cl, and operated in a similar manner by projections f¹; g, g, are rollers on
which the bars rest, the said rollers being provided with loose flanges or collars
projecting up between the bars; the object of these flanges is to facilitate the
to-and-fro movement of the bars and to prevent them from getting bent, thus
keeping the air spaces free; i is the dead plate which is placed, as shewn, some
distance above the top of the bars; j, air grating between the upper surfaces of the
bars and the under side of the dead plate for the admission of air; the back ends
of the bars pass through openings in the guide plate k under the bridge l.
From this arrangement it will be understood that if the lever handle e be
operated the rocking bars c, c', will communicate a backward and forward motion
to the bars; the bars a moving in the opposite direction to the bars a¹, thereby
clearing or breaking up by means of the semicircular projections 6 the clinkers and
scoria, and the air introduced through the grating ; under the dead plate i passes
thoroughly into the fuel, and effects a more perfect combustion thereof and con-
sumption of the smoke.
I will now describe my improvements in furnace doors:―m is the slide or valve
moving on a centre n; the said slide or valve is provided with a counterweight o,
for keeping the valve open for the admission of air through the door; v is the
jacket or casing of the said door, which is also provided with a division plate p,
whereby the air entering the slide or valve has to pass upwards, then over the top
of the division plate p, and then downwards, as shewn, by the arrows and out by
the opening w in the lower part of the casing on to the dead plate i, and endwise
through the fuel, and thus assisting and regulating the combustion of fuel and the
consumption of smoke.
For the automatic closing of this slide I provide the case or box q, shewn in
detached sectional view at Figure 5, which rotates on a pivot or centre 7 on the
door, or it may be above the same; 8, 8, are the conical divisions in the case or
box; t, t, holes for the passage of the sand or other granular material.
By reference to the Drawing it will be seen that if the parts are in the position
shewn in Figure 4, that is to say, the valve being open and the sand or other
granular material in the upper part A of the case or box, the said sand will

page_text: gradually fall into the lower division B of the box and bring the same into the
vertical position, and consequently close the valve by the end of the box pressing
on the bar u (or other suitable contrivance) with which the valve is provided.
Having thus described my said Invention, and the manner of performing the
same, I wish it to be understood that I do not confine myself to the precise details
herein laid down and shewn in the Drawing, as the same may be varied without
departing from the peculiar character of my Invention, but what I do claim is,-
Firstly. The construction and employment of fire-bars, with semicircular pro-
jections on their upper surfaces, in combination with bearing rollers having loose
flanges thereon, the whole arranged and operating substantially as and for the
purposes herein-before described and shewn in the accompanying Drawing,
Secondly. The construction and employment of the grating under the dead
plate for the admission of air to the furnace, as herein-before described and shewn
in the Drawing.
Thirdly. The construction of furnace doors with a casing, having a division, in
combination with a slide or valve in the front of the door, operating as and for
the purposes described.
Fourthly. The employment in combination with a furnace door, constructed as
herein-before described, of the case or box for automatically closing the slide or
valve in the said door.
In witness whereof, I, the said Joseph Sawyer, have hereto set my hand
and seal, this Ninth day of August, in the year of our Lord One thousand
eight hundred and seventy-eight.
Witness,
G. F. REDFERN,
Patent Agent,
4, South Street,
Finsbury,
London.
JOSEPH SAWYER. (L.S.)