IMPROVEMENTS IN STOVES AND FURNACES FOR HEATING AND VENTILATING BUILDINGS
Year: 1876

page_text: LETTERS PATENT to Hugh Lewis McAvoy, of the City of Baltimore, State of
Maryland, United States of America, for the Invention of "IMPROVEMENTS
IN STOVES AND FURNACES FOR HEATING AND VENTILATING BUILDINGS."
Sealed the 21st December 1876, and dated the 26th June 1876.
PROVISIONAL SPECIFICATION left by the said Hugh Lewis McAvoy at the
Office of the Commissioners of Patents on the 26th June 1876.
HUGH LEWIS M° Avoy, of the City of Baltimore, State of Maryland, United
States of America. "IMPROVEMENTS IN STOVES AND FURNACES FOR HEATING
AND VENTILATING BUILDINGS."
My Invention relates, firstly, to a revoluble cover for the exterior casing of the
stove connected with a revoluble cover to the magazine, the said outer cover being
provided at one side with openings for the reception of mica or other illuminative
substance, and at the other with a hinged door placed opposite a corresponding
door in the inner cover or cover to the magazine, through which doors the fuel is
entered, the intention being to allow the said doors to be brought to the front when
the stove is to be supplied with fuel, and then to be turned to the rear exposing
the mica windows to produce an agreeable illuminative effect.
My Invention relates, secondly, to other elements designed to increase the
illuminating surface of the stove, also forming a part of the exterior casing, con-
sisting in doors formed of horizontal bars adapted to receive mica strips or strips of
other illuminative substance in the spaces existing between them, and the whole
constructed to slide circumferentially of the stove, or, being hinged, to open out-
wardly from the central front part thereof.
My Invention relates, thirdly, to improvements in the bed for the fire-clay,
consisting in providing for the reception of the clay, when in a plastic state, a
series of spines or projections upon the annular plates ordinarily laid with fire-
brick, the said spines or projections embedding in the clay and holding it when
in a baked condition firmly in position.
My Invention relates, fourthly, to certain improvements in the grate of the
stove, consisting principally in the use of a plate and connecting devices as sub-
stitutes for the ordinary grate and its attachments.
My Invention relates, fifthly, to certain improvements in the magazine or that
part of the stove in which coal is stored and from which it is fed by gravity to
the grate as the burning coal thereon is reduced in bulk in the process of com-
[Price 6d.]

page_text: bustion, and to the manner of suspending the afore-mentioned bed for the fire-clay,
and the parts attached thereto, within the stove casing whereby a partial rotary
motion may be imparted to the said bed and attachments by means of a bar
inserted through a suitable slot in the front of the casing or a bar secured to a
portion of the plate before mentioned.
In the further description of my Invention which follows due reference must be
had to the accompanying Drawing, in which Figure 1 is a front elevation of the
stove partly in section; Figure 2 a vertical side section of the same; Figure 3 a
sectional plan of the improved stove.
Figure 4 a partly sectional view of a portable heating furnace embodying my
Invention, or modification thereof; and
Figure 5 a partly sectional view of a stove embodying my Invention as adapted
to a fireplace and chimney, and illustrating the manner of conducting heated air
to rooms situated above the room in which the stove is situate. Similar letters of
reference indicate similar parts in all the Figures.
A is the cylinder or casing of the stove fastened to the hollow base B. The
upper end of the casing is conical in form, and a portion thereof cut away for
purposes herein-after described. The conical head of the casing is provided with a
closely fitting revoluble cover C, one side of which is slotted and arranged to be
fitted with mica, which side, when brought to the front, comes over the opening
alluded to, formed by cutting away a portion of the top of the stove. The other
side of the cover has a door a to be used in feeding the stove with fuel. D is a
magazine secured to the inner side of the casing, as herein-after described, and
provided with a conical cap b suspended rigidly by a bolt e from the cover C. This
cap is also provided with a door d´in a position corresponding with that of the door
a. It will be observed that the revolving cover C and cap 6 will move together as
they are both fastened to the bolt c passing through the top of the cylinder E is
an annular plate extending inwardly from the interior of the cylinder or casing
A, in a manner herein-after described, adapted to hold fire-clay, for which purpose
it is provided with the spines or projections d, which embed themselves in the clay
when placed upon the plate E in a plastic state.
A series of rings e are suspended from the plate E extending nearly to the fire-
plate F, which occupies the place usually filled by the grate of ordinary construction.
The plate F is designed to sustain the fire, and is formed with a toothed or fringed
circumference, the spaces between the teeth serving, in connection with the adjacent
apertures e¹ between the rings e, as means by which ashes can escape and air be
admitted to the fire from below. The special use of the rings e is in connection
with the serrated plate F, they being thus constructed and having their edges up
and down to give, while affording great lateral draft room, which is necessary in
view of the small draft space provided in the serrated plate F, the greatest possible
diameter and area to the receptacle for fuel over the moveable grate formed by the
plate F and its appendages. The supporting pieces el between the rings e also
serve, while offering little obstruction, to the draft to preserve the shape of the fire
not intended to be disturbed, when by the shaking of the plate F the dead fire is
thrown out under the lower ring and through the serrations of said plate.
The plate F is pivotted centrally to the cross bar f by means of the yoke g and pin
g, and may be moved or shaken circumferentially by means of the bar h to expel
the accumulated ashes, and is provided with a sliding door h¹ fastened to the said
bar h, by the used of which door the fire is cleared and relieved from clinkers.
The magizine D, before alluded to, is formed of a semi-cylindrical, or nearly semi-
cylindrical, hollow plate i attached to the back of the casing A, and extending
vertically, or nearly vertically, from near the top of the plate E to the conical cap b
of the magazine above described, and a portion of the said casing of a length
corresponding nearly to that of the said plate, and limited circumferentially by the
points of attachment of the hollow plate thereto. By this formation of the magazine
it will be seen that the coal falling therefrom must necessarily be thrown forward,
and forms, when deposited upon the fire-plate F, a body of coal, the back part of

page_text: which is vertical and the front or exposed portion conical, or having flaring sides.
The points of attachment between the hollow plate i and the casing A are placed
well back from the front of the casing A to allow of a large space for the combustion
of gases arising from the burning coal. The hollow plate i in addition to forming
the main part of the magazine D is used as the direct channel for the admission of
air to the interior of the stove to support the combustion of the gases and smoke
therein, and is supplied through the pipe k, the opening of which at the exterior of
the casing is regulated by means of a damper or register k¹. The hole for the
insertion of a poker is represented by k¹¹, which, when not in use, is covered by the
door . G is a jacket extending from the hollow base B, into which the products of
combustion pass by means of the opening G¹. The jacket G is divided vertically
by the partition m into the compartments n and o, and provided with the damper p.
Upon the damper p being closed the stove has no direct communication with the
chimney, and the smoke and other products of combustion are therefore compelled
to pursue the course indicated by the arrows drawn in full lines, viz., through the
compartments n and hollow base B, and thence through the compartment o before
reaching the stove pipe H. This circulation tends to heat the surfaces of the jacket
and hollow base, and thus renders the stove more efficient. When the damper p is
opened a direct outlet is afforded the smoke, which takes the direction shown by the
dotted arrows. The opening of the damper is usually necessary when the fire is
first made in order to increase the draft and allow of the escape of smoke. A cavity r
is formed in the jacket for the passage of air to the stove in case it is to be arranged
to heat upper stories of the building. The stove is enclosed in a case I having a
front K, which may be ornamented. After the magazine has been filled with coal,
and the coal upon the fire-plate F is sufficiently ignited to produce an illuminating
effect, the cover C is turned so as to bring the side having the mica windows to the
front; at the same time the cap b moving with the cover is carried to the rear of
the stove and out of sight. By the use of the plate F, as shown instead of the
ordinary grate, less clinker will be formed, as the current of air passes to the fire
around the periphery of the grate area instead of being intensified in its action at
the centre thereof by reason of the contracted aperture ordinarily left thereat, for
with the usual grate the ashes when formed are thrown to the edges in the
endeavour to dislodge them, necessarily leaving the central area of the grate the
only part sufficiently exposed to furnish draft room. While the liability of the
formation of clinkers is thus diminished, provision is, however, made for such as may
be produced in the openings 8 through which a poker may be introduced.
As before stated the bed for the fire-clay and certain attachments thereto is
suspended within the casing in such manner as to allow of a partial rotary move-
ment being imparted to it. This is accomplished by lodging the said bed upon an
annular flange t projecting inward from the stove. The stove is shown as provided
with doors leading to the interior of the hollow base for cleaning and other purposes.
In Figure 4 the Invention is somewhat modified in construction for the purpose
of adapting it to portable heating furnaces. One of the principal alterations
consists in dispensing with the hollow plate i as a means of conducting air to the
interior of the combustion chamber, and the substitution therefor of a hollow
conical deflector K¹. This construction materially increases the heating capacity of
this class of apparatus when used in conected with an upper fire-pot, consisting of a
fluted cylindrical chamber, or one in which vertical tubes are employed similar to
those used in steam boilers.
In Figures 4 and 5 a large portion of the heat radiated from the inner parts of
the apparatus is utilized by being conveyed through pipes to registers in the upper
stories of the building. Stoves and furnaces having these attachments also serve to
ventilate the lower as well as the upper apartments, strong upward currents of air
being formed with the supply of fresh air drawn from the exterior of the building.
.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Hugh Lewis McAvoy in the Great Seal Patent Office on the 22nd
December 1876.
HUGH LEWIS McAvoy of the City of Baltimore, State of Maryland, United
States of America. "IMPROVEMENTS IN STOVES AND FURNACES FOR HEATING AND
VENTILATING BUILDINGS."
My Invention relates, firstly, to a revoluble cover for the exterior casing of the
stove connected with a revoluble cover to the magazine, the said outer cover being
provided at one side with openings for the reception of mica or other illuminative
substance, and at the other with a hinged door placed opposite a corresponding
door in the inner cover or cover to the magazine, through which doors the fuel is
entered, the intention being to allow the said doors to be brought to the front
when the stove is to be supplied with fuel, and then to be turned to the rear
exposing the mica windows to produce an agreeable illuminative effect.
My Invention relates, secondly, to other elements designed to increase the illu-
minating surface of the stove, also forming a part of the exterior casing, consisting
in doors formed of horizontal bars adapted to receive mica strips or strips of other
illuminative substance in the spaces existing between them, and the whole con-
structed to slide circumferentially of the stove, or being hinged, to open outwardly
from the central front part thereof.
My Invention relates, thirdly, to improvements in the bed for the fire-clay, con-
sisting in providing for the reception of the clay, when in a plastic state, a series of
spines or projections upon the annular plates ordinarily laid with fire-brick, the said
spines or projections embedding in the clay and holding it when in a baked con-
dition firmly in position.
My Invention relates, fourthly, to certain improvements in the grate of the
stove, consisting principally in the use of a plate and connecting devices as sub-
stitutes for the ordinary grate and its attachments.
My Invention relates, fifthly, to certain improvements in the magazine or that
part of the stove in which coal is stored and from which it is fed by gravity to
the grate as the burning coal thercon is reduced in bulk in the process of con-
bustion, and to the manner of suspending the afore-mentioned bed for the fire-clay,
and the parts attached thereto, within the stove casing whereby a partial rotary
motion may be imparted to the said bed and attachments by means of a bar inserted
through a suitable slot in the front of the casing or a bar secured to a portion of the
plate before mentioned.
In the further description of my Invention which follows due reference must be
had to the accompanying Drawing, in which Figure 1 is a front elevation of the
stove partly in section; Figure 2 a vertical side section of the same.
Figure 3 a sectional plan of the improved stove.
Figure 4 a partly sectional view of a portable heating furnace embodying my
Invention, or modification thereof; and
Figure 5 a partly sectional view of a stove embodying my Invention as adapted
to a fireplace and chimney, and illustrating the manner of conducting heated air
to rooms situated above the room in which the stove is situate. Similar letters of
reference indicate similar parts in all the figures.
A is the cylinder or casing of the stove fastened to the hollow base B. The
upper end of the casing is conical in form, and a portion thereof cut away for
purposes herein-after described. The conical head of the casing is provided with a
closely fitting revoluble cover C, one side of which is slotted and arranged to be
fitted with mica, which side, when brought to the front, comes over the opening
alluded to, formed by cutting away a portion of the top of the stove. The other
side of the cover has a door a to be used in feeding the stove with fuel. D is a
magazine secured to the inner side of the casing, as herein-after described, and
provided with a conical cap b suspended rigidly by a bolt c from the cover C.

page_text: This cap is also provided with a door d in a position corresponding with that of the
door a.
It will be observed that the revolving cover C and cap b. will move
together, as they are both fastened to the bolt e passing through the top of the
cylinder. E is an annular plate extending inwardly from the interior of the cylinder
or casing A, in a manner herein-after described, adapted to hold fire-clay, for which
purpose it is provided with the spines or projections d, which imbed themselves
in the clay when placed upon the plate E in a plastic state.
A series of rings e are suspended from the plate E extending nearly to the fire-
plate F, which occupies the place usually filled by the grate of ordinary construction.
The plate F is designed to sustain the fire, and is formed with a toothed or fringed
circumference, the spaces between the teeth serving, in connection with the adjacent
apertures e¹ between the rings e, as means by which ashes can escape and air be
admitted to the fire from below. The special use of the rings e is in connection
with the serrated plate F, they being thus constructed and having their edges up
and down to give, while affording great lateral draft room, which is necessary in
view of the small draft space provided in the serrated plate F, the greatest possible
diameter and area to the receptacle for fuel over the moveable grate formed by the
plate and its appendages. The supporting pieces el between the rings e also
serve, while offering little obstruction to the draft, to preserve the shape of the fire
not intended to be disturbed, when by the shaking of the plate F the dead fire is
thrown out under the lower ring and through the serrations of the said plate.
The plate F is pivotted centrally to the cross bar f by means of the yoke g and
pin g, and may be moved or shaken circumferentially by means of the bar h to
expel the accumulated ashes, and is provided with a sliding door h¹ fastened to the
said bar h, by the use of which door the fire is cleared and relieved from clinkers.
The magazine D, before alluded to, is formed of a semi-cylindrical, or nearly
semi-cylindrical, hollow plate i attached to the back of the casing A, and extending
vertically, or nearly vertically, from near the top of the plate E to the conical
of the magazine above described, and a portion of the said casing of a length
corresponding nearly to that of the said plate and limited circumferentially by the
points of attachment of the hollow plate thereto. By this formation of the magazine
it will be seen that the coal falling therefrom must necessarily be thrown forward,
and forms, when deposited upon the fire-plate F, a body of coal, the back part of
which is vertical and the front or exposed portion conical, or having flaring sides.
The points of attachment between the hollow plate i and the casing A are placed
well back from the front of the casing A to allow of a large space for the combustion
of gases arising from the burning coal. The hollow plate i, in addition to forming
the main part of the magazine D, is used as the direct channel for the admission of
air to the interior of the stove to support the combustion of the gases and smoke
therein, and is supplied through the pipe k, the opening of which at the exterior of
the casing is regulated by means of a damper or register 1. The hole for the
insertion of a poker is represented by ³, which, when not in use, is covered by the
door . G is a jacket extending from the hollow base B, into which the products
of combustion pass by means of the opening G¹. The jacket G is divided vertically
by the partition m into the compartments n and o, and provided with a damper p.
Upon the damper p being closed the stove has no direct communication with the
chimney, and the smoke and other products of combustion are therefore compelled
to pursue the course indicated by the arrows drawn in full lines, viz., through the
compartments n and hollow base B, and thence through the compartment o before
reaching the stove pipe H. This circulation tends to heat the surfaces of the jacket
and hollow base, and thus renders the stove more efficient. When the damper p is
opened a direct outlet is afforded the smoke, which takes the direction shown by
the dotted arrows. The opening of the damper is usually necessary when the fire
is first made in order to increase the draught and allow of the escape of smoke. A
cavity is formed in the jacket for the passage of air to the stove in case it is to be
arranged to heat upper stories of the building. The stove is enclosed in a case I

page_text: having a front K, which may be ornamented. After the magazine has been filled
with coal, and the coal upon the fire-plate F is sufficiently ignited to produce an
illuminating effect, the cover C is turned so as to bring the side having the mica
windows to the front at the same time the cap 6 moving with the cover is carried
to the rear of the stove and out of sight. By the use of the plate F, as shown,
instead of the ordinary grate, less clinker will be formed, as the current of air passes
to the fire around the periphery of the grate area instead of being intensified in its
action at the centre thereof by reason of the contracted aperture ordinary left
thereat, for with the usual grate the ashes when formed are thrown to the edges in
the endeavour to dislodge them, necessarily leaving the central area of the grate the
only part sufficiently exposed to furnish draught room. While the liability of the
formation of clinkers is thus diminished, provision is, however, made for such as
may be produced in the opening 8 through which a poker may be introduced.
As before stated the bed for the fire clay and certain attachments thereto is sus-
pended within the casing in such manner as to allow of a partial rotary movement
being imparted to it. This is accomplished by lodging the said bed upon an
annular flange t projecting inward from the stove. The stove is shown as provided
with doors leading to the interior of the hollow base for cleaning and other purposes.
In Figure 4 the Invention is somewhat modified in construction for the purpose
of adapting it to portable heating furnaces. One of the principal alterations consists
in dispensing with the hollow plate i as a means of conducting air to the interior
of the combustion chamber, and the substitution therefor of a hollow conical de-
flector K¹. This construction materially increases the heating capacity of this class
of apparatus when used in connection with an upper fire-pot consisting of a fluted
cylindrical chamber or one in which vertical tubes are employed sünilar to those
used in steam boilers.
In Figures 4 and 5 a large portion of the heat radiated from the inner parts of
the apparatus is utilized by being conveyed through pipes to registers in the
upper stories of the building.
Stoves and furnaces having these attachments also serve to ventilate the lower
as well as the upper apartments, strong upward currents of air being formed with
the supply of fresh air drawn from the exterior of the building.
Having thus described and ascertained the nature of my said Invention, I desire
it to be understood that I claim, as secured to me under the above in part recited
Letters Patent, and for the purpose above set forth.
First. In a heating and ventilating fireplace, stove, or furnace, the casing A in
combination with the revoluble cover C of the same, connected, as shown, with the
revoluble cover or cap b of the magazine D, the said cover C being provided with
mica windows, as described, and furnished, in connection with the inner cover or
cap b, with doors for entering fuel to the said magazine.
Second. In a heating and ventilating fireplace, stove, or furnace, the casing A. in
combination with the horizontally barred doors adapted for the insertion of mica or
other illuminative substance as and for the purposes described.
Third. In a heating and ventilating fireplace, stove, or furnace, the annular
flanget projecting from the inner surface of the casing A, in combination with the
annular plate E, furnished with the projecting spines d', as described.
Fourth. In a heating and ventilating fireplace, stove, or furnace, the annular
plate E, provided with the spines d', as shown, in combination with the series of
pendant or suspended horizontally placed rings e as specified.
Fifth. In a heating and ventilating fireplace, stove, or furnace, the combination
of the annular plate E, pendant rings e, and fire-plate F, fitted with sliding door for
removing ashes, &c., as specified.
Sixth. In a heating and ventilating fireplace, stove, or furnace, the magazine D,
a portion of which is constructed of a hollow plate i to allow of the admission of
air heated in its passage to the base of the magazine to support the combustion of
the gases. arising from the burning coal, as set forth.
Seventh. In a heating and ventilating fireplace, stove, or furnace, the hollow

page_text: plate i attached to the inner surface of the casing A, the said parts in connection
with the conical top and cap or cover b forming the magazine D.
Eighth. In a heating and ventilating fireplace, stove, or furnace, the partially
rotating fire-pot, consisting of the annular plate E and pendant rings or bars e, as
and for purposes described.
Ninth. In a heating and ventilating fireplace, stove, or furnace the radiating
jacket G, divided by the partition m into the compartments n and o, the said par-
tition having the damper p for changing the direction of the draught as described.
In witness whereof, I, the said Hugh Lewis M°Avoy, have hereunto set my
hand and seal, this Thirtieth day of October, in the year of our Lord One
thousand eight hundred and seventy-six.
HUGH LEWIS M'AVOY. (L.S.)