Improved Door for Stoves and Fire-places.
Year: 1899

page_text: Improved Door for Stoves and Fire-places.
I, HERMAN SVENSSON, of Munksjö, Jönköping, Sweden, Mechanical Engineer,
lo hereby declare the nature of this invention to be as follows:-
The
This invention relates to fire-doors for stoves, grates, fire-places etc.
object of the invention is to obtain the greatest possible heating effect from the
fuel and in consequence thereof saving of fuel as well as an improved appear-
ance of the fire-place.
As English stoves or fire-places are usually not provided with dampers nor
with doors no warmth is retained in the room after the fuel has ceased to burn,
owing to the fact that the strong draught causes a sudden cooling of the embers
and walls of the hearth. This invention consists in arranging the fire-place
in such a manner that, when the fuel has ceased to give flames, the draught can
be prevented or regulated in the most complete manner, so that the embers
will for some time be kept in a glowing state for reasons hereinafter given.
The way of preventing the draught is by means of a fire-door placed before the
It is obvious that such an
fire-place and adapted to be airtightly closed.
arrangement is to be preferred to a damper above the fire-place, as it is impos-
sible to make the damper sufficiently airtight and, further, the poisonous gas
of carbonic oxide, produced when the damper is closed too soon, on account of
the fuel being incompletely burned, cannot escape through the chimney but
enters into the room.
In fire-places where the airtight fire-doors according to this invention are
used, there will be a slow circulation of the air when the door is closed and.
consequently, a slow combustion of embers will take place. The heated air rises
through the chimney, and the cool air descends, supplying the embers with the
As this combustion is not accelerated
oxygen necessary for the combustion.
by any draught, it takes place slowly, and not only when the embers are not
deprived of all their fuel, but as long as there is any warm air in the fire-place
the heat will radiate to the walls of the fire-place and from said walls to the
room.
The accompanying drawing illustrates a fire-door constructed according to
this invention. Figure 1 shows the door in elevation, Figure 2 a vertical section
through the sockets of the closing mechanism, and Figure 3 a horizontal section
of the door. Figure 4 shows a modification of the closing mechanism. Fig. 5
shows the upper part of the last fig. on an enlarged scale.
The fire door shown in the drawing consists chiefly of two door-halves a of
cast-iron or other suitable material and is hung on the hinges b, which are fitted
in a frame c, immured in the hearth-opening. The tightening material between
the two doors and between each of the doors and the frame consists of pack-
ings of asbestos, cement or other suitable material. In the doors may be
O placed small panes of mica, in order to transmit the rays of light from the
embers. These panes are also tightly secured to the door by packings of asbestos.
One of the doors (the right hand in Figure 1) is pressed against the frame c by

page_text: means of screws f, the upper and lower conical ends of which enter, when the
doors are closed, into conical sockets h, fitted on the frame c. The outer door
transfers the pressure to the inner door through the packing d, thus pressing
the said door against the packing of the frame.
The arrangement for securing the doors consists of a handle k, one end of
which clasps around a square rod 7, whose ends enter into the inner ends of
The doors are opened and closed by only turning the handle once
from the right-hand side to the left or vice versa. The pitch of the screws is
large enough to cause the doors to press firmly against the frame
the screws.
Instead of the threaded rods by means of which the doors are pressed against
the frame plain round rods without threads can be used, for instance by using
excentrics m (Fig. 4) instead of the conical ends, and cylindrical holes instead
of conical holes in the sockets h. In such case spiral springs n may be arranged
to act upon the round rods at the ends of the square rod in order to press the
rods foutward, so as to enter into the sockets. The eccentric ends, the axis
of which are parallel to the axis of the rods, must have an oblique plane o
(Fig. 5), inclined towards the doors, when the door is to be shut, and another
oblique plane p, inclined from the doors, when the door is to be opened. In
the former case the handle stands at right angles to the fire-door, in the latter
to the left and parallel to it. When the doors are tightly shut, the handle
stands to the right.
The hinges and the sockets h are fastened to the frame by means of gas
threads, for the purpose of adjusting the doors with precision.
Especially when burning coal and coke the air-valves on the fire-doors will be
of use. By shutting the doors and regulating the draught by means of these
valves, a slow and effective combustion of the fuel is caused.
:
In the fire-place, at some distance from the bottom of it, a grate or the like
(not shown in the drawing) may be immured or fixed in any suitable way.
The frame c, to which the fire-doors are fastened, can be lengthened inwards
to a cast-iron case, formed by two side-walls, one back-wall, one bottom, and a
roof, with a hole for the combustion gases. The back- and side-walls as well
as the closed part of the roof may be coated with fire-proof bricks. The case
may be hermetically sealed for instance by fire-clay placed around the edges
of the upper side of the roof.
The described arrangements may, of course, be applied to old as well as to
new fire-places in which an air-tight fire-door is desired.
It will be understood that I do not limit myself to the precise details herein-
before described but can make several alterations in the details without depart-
ing from the principles of the invention.
Datad his 4th day of Dasamihan 1800
improved Door for Stoves and Fire-places.
I, HERMAN SVENSSON, of Munksjö, Jönköping, Sweden, Mechanical Engineer,
do hereby declare the nature of this invention and in what manner the same
is to be performed to be particularly described and ascertained in and by the
following statement:―
This invention relates to fire-doors for stoves, grates, fire-places etc. The
object of the invention is to obtain the greatest possible heating effect from the

page_text: uel and in consequence thereof saving of fuel as well as an improved appear-
nce of the fire-place.
As English stoves or fire-places are usually not provided with dampers nor
with doors no warmth is retained in the room after the fuel has ceased to burn,
Owing to the fact that the strong draught causes a sudden cooling of the embers
and walls of the hearth. This invention consists in arranging the fire-place
in such a manner that, when the fuel has ceased to give flames, the draught can
so that the embers
be prevented or regulated in the most complete manner
will for some time be kept in a glowing state for reasons hereinafter given.
The way of preventing the draught is by means of a fire-door placed before the
hearth-opening and adapted to be air-tightly closed. It is obvious that such an
arrangement is to be preferred to a damper above the fire-place, as it is impos-
sible to make the damper sufficiently air-tight and, further, the poisonous gas
of carbonic oxide produced when the damper is too soon closed, on account of
the fuel being incompletely burned, cannot escape through the chimney but
enters into the room.
In fire-places where the airtight fire-doors according to this invention are
used there will be a slow circulation of the air when the door is closed and,
consequently, a slow combustion of embers will take place. The heated air rises
through the chimney, and the cool air descends, supplying the embers with the
oxygen necessary for the combustion. As this combustion is not accelerated
by any draught, it takes place slowly, and not only when the embers are not
deprived of all their fuel but as long as their is any warm air in the fire-place
the heat will radiate to the walls of the fireplace and from said walls to the
room.
The drawing accompanying the Provisional Specification illustrates a fire-
door constructed according to this invention.
Figure 1 shows the door in elevation.
Figure 2 a vertical section through the sockets of the closing mechanism,
and
Figure 3 a horizontal section of the door.
Figure 4 shows a modification of the closing mechanism.
Figure 5 shows the upper part of the last figure on an enlarged scale.
The fire door shown in the drawing consists chiefly of two door-halves a of
cast-iron or other suitable material and is hung on the hinges b, which are fitted
in a frame e, immured in the hearth-opening. The tightening material between
the two doors and between each of the doors and the frame consists of pack-
ing of asbestos, cement or other suitable material. In the doors may be
placed small panes of mica, in order to transmit the rays of light from the
embers. These panes are also tightly secured to the door by packings of asbestos.
One of the doors (the right hand in Figure 1) is pressed against the frame by
means of screws f, the upper and lower conical ends of which enter, when the
The outer door
doors are closed, into conical sockets h, fitted on the frame c.
transfers the pressure to the inner door through the packing d, thus pressing
the said door against the packing d' of the frame.
t
The arrangement for securing the doors consists of a handle k, one end of
which clasps around a square rod I, whose ends enter into the inner ends of
the screws. The doors are opened and closed by only turning the handle once
The pitch of the screws is
from the right-hand side to the left or vice versa.
O large enough to cause the doors to press firmly against the frame
Instead of the threaded rods by means of which the doors are pressed against
the frame plain round rods without threads can be used, for instance by using
eccentrics m (Figure 4) instead of the conical ends and cylindrical holes instead
of conical holes in the sockets h. In such case spiral springs n may be arranged
5 to act upon the round rods at the ends of the square rod in order to press the
rods foutward, so as to enter into the sockets. The eccentric ends, the axes
of which are parallel to the axes of the rods, must have an oblique plane o

page_text: (Figure 5), inclined towards the doors, when the door is to be shut, and another
oblique plane p, inclined from the doors, when the door is to be opened. In
the former case the handle stands at right angles to the fire-door, in the latter
to the left and parallel to it; when the doors are tightly shut, the handle
stands to the right.
The hinges and the sockets are fastened to the frame by means of gas
threads, for the purpose of adjusting the doors with precision.
Especially when burning coal and coke the air-valves on the fire-doors will be
of use.
By shutting the doors and regulating the draught by means of these
valves, a slow and effective combustion of the fuel is caused.
In the fire place, at some distance from the bottom of it, a grate or the like
(not shown in the drawing) may be immured or fixed in any suitable way.
The frame e, to which the fire-doors are fastened can be lengthened inwards
to a cast-iron case, formed by two side-walls, one back-wall, one bottom, and a
roof, with a hole for the combustion gases. The back and side walls as well
as the closed part of the roof may be coated with fire-proof bricks. The case
may be hermetically sealed for instance by fire-clay placed around the edges
of the upper side of the roof.
The described arrangements may, of course, be applied to old as well as to
new fire-places in which an air-tight fire-door is desired.
It will be understood that I do not limit myself to the precise details herein-
before described but can make several alterations in the details without depart-
ing from the principles of the invention.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
1. The arrangement, for fire-doors of stoves and fireplaces, of the packings d d',
of asbestos or other suitable material, between the doors and between the doors
and the frame, with means for pressing the doors against the frame, substan-
tially as described.
2. Means for closing the fire-doors of stoves and fireplaces, consisting of a
handle attached to a rod provided with square ends fitting into screws arranged
in sockets, the outer conical ends of the rods provided with said screws being
adapted, on the handle being operated, to enter conical sockets fixed on the
frame, whereby the doors are pressed together and against the frame, substan-
tially as described.
3. Means for closing the fire-doors of stoves and fireplaces, consisting of a
handle attached to a rod provided with square ends fitting into rods provided
with springs the outer ends of said rods being furnished with cams or eccentrics
provided with oblique planes and being adapted, when the handle is operated
to enter sockets fixed to the frame whereby the doors are pressed together and
against the frame, substantially as described.
4. An improved door for stoves, fireplaces and the like, substantially as
described and illustrated in the accompanying drawings.
Dated the 31st day of August 1900.
W. P. THOMPSON & Co.,
Of London, Liverpool, Manchester and Birmingham.