AN IMPROVED CHIMNEY TOP OR COWL AND VENTILATOR
Year: 1881

page_text: LETTERS PATENT to Maurice Delmard, of Plumstead Common, in the County
of Kent, Gentleman, for an Invention of "AN IMPROVED CHIMNEY TOP OR
COWL AND VENTILATOR."
PROVISIONAL SPECIFICATION left by the said Maurice Delmard at the
Office of the Commissioners of Patents on the 10th June 1881.
MAURICE DELMARD, of Plumstead Common, in the County of Kent, Gentleman..
"AN IMPROVED CHIMNEY TOP OR COWL AND VENTILATOR."
My Invention relates to an improved apparatus chiefly designed to serve as a
chimney top or cowl, but which may be advantageously used for ventilating
dwelling houses and other buildings.
The said apparatus is constructed as follows, that is to say, it has a vertical
tube which may be placed on an ordinary chimney or may have a lateral branch to
connect with the pipe of a gas or other stove.
The upper end of the said tube is formed with a flange made curved or conical
so as to give it a bowl or funnel shape. Over this flange I place a bowl shaped or
conical plate which corresponds in form with the said flange, and which covers the
same and the aporture of the tube, so that the direct passage of air up or down
through the said tube is prevented, but a spaco is left between the said flange and
plate at the periphery of the same to form a lateral aperture for the outward passage
of the products of combustion. I prefer that the said bowl shaped or conical plate
should be provided with a cover or diaphragm so formed as to present a convex
surface at the top to prevent the accumulation of water in the said curved or conical
plate.
The above described portions of the apparatus are enclosed in a box or cylinder
through the bottom of which the said vertical tube extends. At the top of this
box or cylinder there is a small vertical chamber which is perforated with small
holes. The bottom of the said cylinder is also perforated, and when the said vertical
tube is formed with a lateral branch I perforate the lower end of the said tube.

page_text: These perforations are provided for the escape of the smoke or products of com-
bustion, which ascend through the said vertical tube.
may modify the above described construction by using instead of the aforesaid
box or cylinder a curved plate with a vertical flange extending downward below
the lateral outlet aperture at the top of the vertical tube. This flanged plate
leaves an opening or passage all around the saune between its flange and the top
of the vertical tube for the escape of the products of combustion, and it may or
may not be provided with a perforated portion or chamber at the top of the
apparatus.
The whole of the parts of the said apparatus may be formed of sheet-iron or of
other suitable material. The bowl.shaped plate may be attached to the flange of
the vertical tube by light brackets. The outer box or cylinder may also be in
like manner attached to the said vertical tube.
It will be obvious that as the only communication between the vertical tube
and the space surrounding the same is through the lateral passage around the top
of the said tube, and as the said plate or diaphragm extends over or covers the top
of the latter, the smoke, if driven back through the. perforated upper chamber,
cannot enter and return down through the said vertical tube, but will find an exit
from the cylinder through the perforations in the bottom of the same, and the
upward draught will not be impeded.
In using this apparatus as a ventilator it may be placed in any convenient part
of tho roof or ceiling, or on a pipe extending therefrom. The foul air from the
room will ascend through the said vertical pipe, and its return will be prevented
by the means above specified.

page_text: My invention relates to improved, apparatus comprising a camney top or COWL
and a ventilator for dwelling houses and other buildings.
The said Invention is illustrated in the accompanying' Drawings, in which
Figure 1 is an elevation partly in section of my improved chimney cowl and
ventilating apparatus.
Figure 2 is a vertical section of the lower in-door portion of the ventilating
apparatus.
Figures 3 and 4 are vertical sections of the burner of the said ventilating
apparatus, and
Figure 5 represents a modification of the same hereinafter described.
Figure 6 is a plan or top view, and
Figure 7 is a vertical section of the said chimney top or cowl.
Figures 8, 9, 10, 11, and 12 are vertical sections showing modifications of tho
said cowl.
Figure 13 is a side elevation illustrating another modification of the same.
It will be seen that these Figures are not all drawn to the same scale.
Liko letters indicate the same parts throughout the Drawings.
The said apparatus, as shewn in Figure 1, consists of the ventilator a (which
may also serve as a heater) and the cowl b. The latter has a vertical tubo c which
may be placed on an ordinary chimney, or may havo, as shewn, a lateral branch d
to connect with the pipe of the gas or other stove or ventilator a.
The upper end of the said vertical tube c is formed with a flange e, which may
be made curved or conical so as to give it a bowl or funnel shape, as shewn in
Figures 7, 8, 9, 10, 11. Over this flange e I place a bowl-shaped or conical plate f
which corresponds in form with the said flange, and which covers the same and the
outlet aperture of the tube c, so that the direct passage of air up or down through
the said tube is prevented, but a space is left between the said flango e and plateƒ
at the periphery of the same to form a lateral aperture g for the outward passage
of the products of combustion. I prefer that this said bowl shaped or conical
plate should be provided with a cover or diaphragm h, as shown in Figures 9,
10, 11, so formed as to present a convex upper surface to prevent the accumulation
of water in the said curved or conical plate. Figure 12 shows a modification,
in which the said flange e and plate are made flat instead of curved or
conical.
The above described portions of the apparatus are enclosed in a box or cylinder i,
through the bottom of which the said vertical tube c extends. At the top this
box or cylinder i is formed or provided with a small chamber which is perforated
with small holes as shown. The upper portion and the bottom of the said cylinder ¿
are also perforated, as shown at kand ³, and when the said vertical tube c is formed
with a lateral branch, as shown in Figure 1, I perforate the lower end of the said
tube at . These perforations are provided for the escape of the smoke or products
of combustion or condensation which will ascend through the said vertical tubo c.
1 further modify the above described construction by using instead of the aforesaid
box or cylinder i a curved plate with a vertical flange extending downward below
the lateral outlet aperture at the top of the vertical tube c, and in some cases I
make the latter conical, that is to say, I form its upper end of smaller diameter
than its lower end.

page_text: In the modification of my Invention shewn in Figure 131 employ a semi-
circular hood or cap m whose flange m' is arranged to cover the holes h. The said
cap is supported to turn freely upon a centre point at n, and is provided with a
vane m², whereby it will always be turned by the wind into the proper position
to prevent a downward draught through the holes on the windward side of the
cowl. This flanged cap is so arranged as to leave an opening or passage all around
the same between its Bange and the top of the vertical tube for the escape of the
products of combustion, and it may or may not be provided with a perforated
portion or chamber at the top of the apparatus.
The whole of the parts of the above described apparatus may be formed of
sheet-iron or of other suitable material. The plate may be attached to the
flange 6 of the vertical tube by light brackets. The outer box or cylinder i may
also be in like manner attached to the said vertical tube.
It will be obvious that as the only communication between the vertical tube c
and the space surrounding the same is through the lateral passage g around the top
of the said tube, and as the plate f extends over or covers the top of the latter, the
smoke if driven back through the perforated upper chamber cannot enter and
return down through the said vertical tube, but will find an oxit from the cylinder
through the perforations in the bottom of the same, and the upward draught will
not be impeded..
In adapting my Invention to the purposes of ventilation the said cowl may be
placed in any convenient part of the roof or on a pipe extending through one of the
walls of the building to the indoor part of the ventilating apparatus, as shewn in
Figure 1. This ventilating apparatus consists of the gas-stove o, through which
passes the pipe p. This pipe extends at its lower end to the outside of the building,
and at its upper end opens into the room or apartment to be ventilated. In the
stove and below the said pipe, as shown in Figures 1 and 2, I place a burner q.
The annular space between the outer casing of the store o and the pipe p is supplied
through apertures o* at the bottom of the stove with air from the room or apart-
ment, and communicates through the branch pipo d with the vertical pipe c, but
has not any outlet at the top of the stove, or any communication with the interior
of the pipe p. It will therefore be obvious that when the burner q is lighted it
will warm the air in the said annular space, and thereby cause an upward draught
or current through the said space, which will draw the vitiated air from the room
or apartment and expel it through the cowl b. At the same time the air within
the pipe p will be heated and ascend into the room, taking with it into the same
a plentiful supply of fresh air, which may be more or less heated as desired by
regulating or adjusting the said burner. At the lower end of the stove o I arrange
a cone o¹, which when a down draught of air occurs causes such air to pass through
openings at o³, and consequently protects the burner q so as to prevent the
extinguishing of the gas by such down draught.
I prefer to use a burner constructed as shown in Figures 3 and 4. This burner
has a gas inlet piece which is enclosed within the tube_s. The portion of the
latter immediately surrounding the gas inlet piece is perforated with a series of
holes s'. Upon this portion of the tubes is fitted a short tube or sleeve t also
perforated with a sorics of holes t'.
This sleeve has a small handle t2, whereby it may be turned to adjust its holes t¹
into or out of coincidence with the holes s¹. I can thereby either admit air to or
exclude it from the interior of the tube 8, so that the said burner will burn mixed
air and gas, or gas alone.
It is obvious however that if desired I may use any other convenient burner in
my improved ventilator or stove; for instance, I in some cases employ the burner
illustrated in Figure 5. In this burner I dispense with the adjustable sleeve t and
employ in the place of the same a tube or sleeve u which extends nearly to the
top of the tubes, as shown. In the upper end of the said tube I form a series of
apertures u, through which air passes into the annular space v between the
tubes u, 8, and downward to the apertures s¹, through which it enters and mixes

page_text: with the gas. When this device is employed if a sudden down draught of air
occurs the flame will be forced through the holes s' and up through the holes u¹,
so that the gas which subsequently issues from the upper end of the pipes will be
ignited by the flame passing through the said holes u¹.
Having thus fully described my said Invention, and the manner of performing
the same, I wish it understood that I claim,-
First. The chimney top or cowl consisting of the vertical pipe whose upper end
is enclosed within a perforated box or casing, and is provided with a flange and
plate either with or without the cover or diaphragm, substantially as shewn in
Figures 6 and 7, or in any of the modifications thereof herein described, which
flange and plate are so arranged that the direct upward or downward passage of
air from or into the said pipe is prevented while free space is left between the
said flange and plate for the escape of the products of combustion or foul air, as
above set forth.
Second. The combination of the said chimney top or cowl with apparatus inside
a room or apartment, substantially as shown in Figures 1 and 2, in which apparatus
the heat of the gas or other burner is utilized to cause a draught from the room or
apartment through the stove and the said cowl outward, and from the outside of
the room or building through the stove into the room or apartment for the purposes
specified.
In witness whereof, I, the said Maurice Delmard, have hereunto set my hand
and seal, this Ninth day of December, in the year of our Lord One
thousand eight hundred and eighty one.
MAURICE DELMARD. (L.S.)