An Improved Chimney Top or Ventilator.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
An Improved Chimney Top or Ventilator.
I, WILLIAM SHEPHARD SHREEVE, Shrewley, Warwick, Estate Agent, do hereby
declare the nature of this invention to be as follows:-
The chimney top or ventilator consists of a hollow truncated cone, fixed on a
suitable base for setting on a chimney stack, roof, or other desired position ;
having one or more hollow truncated cones fitted over it, cap fashion, but with a
space between the cones-the upper cone, which I call the cap cone, being sup-
ported on vertical divisions which divide the space between the cones into
compartments or gills, so arranged as to catch the wind and to conduct it over
the top or orifice of the lower cone, and so exert a sucking or abstracting force
above at the top of the lower cone. I also provide an inverted cone or cover,
convex below and concave above, supported above the upper cone, and sufficiently
high above it to allow of the smoke or other vitiated air to pass out; this
inverted cone is to prevent down draft and assist in creating up draft by divert-
ing any current of air having a tendency to fall vertically down the chimney or
ventilator. When the air is stirred by wind, it impinges on the sides of the
bottom
the
the gills between
&
upper
lower
cone on the windy side, and passing over the top or orifice of the lower cone,
creates an upward current-the inverted cone cover above offers no obstacle to
the rising air, but splits it in its ascent; and at same time deflects any wind
having a tendency to blow down the cone, and creates an upward draft by the
lateral movement of the air above the top of the cone, caused by the deflection.
The upper cone or cap cone may be corrugated vertically so that the corru-
gations form the gills up which the air rushes as it impinges upon the lower
cone.
come
and rushes up
The material for construction may be either metal or earthenware; and the
chimney top or ventilator may be made of an obelisk shape instead of conical
if desired.
1
1000
I, WILLIAM SHEPHARD SHREEVE, of Shrewley, Warwick, Estate Agent, do hereby
declare the nature of this invention and in what manner the same is to be
[Price 8d1

page_text: performed, to be particularly described and ascertained in and by the following
statement:
The chimney top or ventilator consists of a hollow truncated cone, fixed on a
suitable base for setting on a chimney stack, roof, or other desired position;
having one or more hollow truncated cones fitted over it, cap fashion; but with a
space between the cones-the upper cone, which I call the cap cone, being
supported on vertical divisions, which divide the space between the cones
into compartments or gills, so arranged as to catch the wind, and to conduct it
over the top, or orifice, of the lower cone, and so exert a sucking or abstracting
force above, at the top of the lower cone.
I also provide an inverted cone, or cover convex below and concave above,
supported on legs or bands above the upper cone, and sufficiently high above it
to allow of the smoke or other vitiated air to pass out freely; this inverted cone
is to prevent down draft and assist in creating up draft, by diverting any cur-
ent of air having a tendency to fall vertically down the chimney or ventilator.
When the air is stirred by wind, it impinges on the sides of the bottom
cone and rushes up the gills, formed by the vertical divisions between the
upper and lower cone on the windward side, and passing over the top or orifice
of the lower cone, creates an upward current; the inverted cone cover above
offers no resistance to the rising current of air, but splits it in its ascent; and
at same time deflects any wind having a tendency to flow directly down the cone
or ventilator and creates an upward draft by the lateral movement of the air
thus deflected.
This cover is supported on rods or legs at the desired height above the orifice
of the flue or top cone, and thus allows the smoke or vitiated air to escape, and
in the case of a chimney, allows of its being swept without hindrance.
The outer cone also keeps the inner cone warmer, and thus tends to create an
upward draft.
The upper cone or cap cone may be corrugated vertically, so that the corruga-
tions forin the gills up which the air rushes as it impinges upon the lower cone.
The material for construction may be either metal or earthenware; and the
chimney top may be made of any desired shape on plan.
On the accompanying drawing, Figure 1, is a section; the dotted lines indicate
arrangements for short and longer cones; Figure 2, is an elevation, showing
the arrangement for fixing the ventilator or cowl on an ordinary pipe or chimney
pot, this consists of a metal band girding the base of the cowl, & provided,
with a bolt & nut by which the band may be tightened around the pot or pipe &
securely held in position. Figure 3, is a plan of lower cone looking down, with
the four or more divisions for forming the gills.
There is a small pipe from the concave cover, or inverted cone over the top of
flue, which conducts any water which may fall into it, over the side of the
cone, and the flue is thus kept dry.
The long cones direct the current of air upwards and across the orifice of
flue and are for that purpose only, and are thus unlike the louvres generally
used at top of cowls or pots, which have very little lap, and allow the smoke to
pass between them, and on account of their construction, the air or wind mingles
with the smoke, & passes down & through the louvres, unlike the arrangement
which I have described, which has only an upward current.
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 inverted cone, or cover to flue, concave above and convex below, for
diverting down-draft and excluding damp.
2. The combination of the long cones and the cover above, and the vertical
divisions between the cones, whereby the current of air caused by the wind

page_text: impinging on the lower cone, is conducted upwards by the gills so formed, and
discharged over the orifice of the flue or ventilator.
3. The arrangement of the long cones with divisions as described above, with or
without the cone cover.
4. The band arrangement in combination with the above to enable the venti-
lator or cowl to be fitted to any existing pot or flue.
Dated this 23rd day of June 1900.
W. S. SHREEVE,
Shrewley, Warwick.