Improvements in Ventilating Cowls.
Year: 1891

page_text: Date of Application, 7th Feb., 1891
Complete Specification Left, 23rd Mar., 1891-4ccepted, 25th Apr., 1891
PROVISIONAL SPECIFICATION.
Improvements in Ventilating Cowls.
1, JOHN BARTLETT, of No. 37, Cuthill Road, Camberwell, in the County of
Surrey, Engineer, do hereby declare the nature of this invention to be as
follows:-
My invention relates to an improved construction of ventilating cowl, more
particularly applicable to gas lamps, but also applicable in all cases where ventilators
are used, whereby, while a free exit is allowed for the combustion gases or vitiated
air, the interior of the lamp or other space to be ventilated is protected against
down draught or gusts of wind.
For this purpose 1 construct on the upper end of the ventilating pipe or flue a
chamber of rectangular or other suitable section, within which is a second smaller
chamber closed at top and having sides that slope slightly outwards in the direction
from the bottom to the top while at bottom it communicates with the pipe or flue.
In the sloping sides of the chamber are formed a number of openings and to the
upper edge of these openings are loosely hung light tale flaps.
Owing to the outward sloping or overhanging position of the sides of the chamber,
these flaps, which hang vertically, are, under ordinary circumstances, somewhat
removed from the openings, and the collective area of the free spaces thus formed
between the flaps and the edges of the openings is amply sufficient to allow of the
free escape of the combustion gases or vitiated air. On the occurrence of a down
draught or gusts of wind however, the outward pressure of the air upon the tale
flaps on one or more sides of the chamber will cause them to close upon the openings
and thus prevent the wind from penetrating into the lamp flue, while the flaps on
the side or sides of the chamber that are not affected by the wind will still allow
the free egress of the gases.
The outer chamber of the cowl has its top formed with an upward slope and a
central opening, the edge round such opening being formed with an outward
curvature while over the opening at a suitable distance therefrom is a sloping cap.
Thus the wind penetrating between the top of the chamber and the cap will be
deflected upward by the curved edge away from the opening.
The bottom of the space between the inner and outer chambers is provided with
small holes at its lowest points, through which can escape any water of condensation
or rain that may penetrate into the outer chamber, without penetrating into the
inner chamber.
It will be seen that the above described construction of ventilating chamber with
tale flaps will have the advantage over the ordinary construction of ventilators with
talc flaps, that whereas these are always made with their sides at such an inward
sloping angle that the flaps remain closed upon the opening thereof, so that they
have to be forced open by the air currents before any ventilation can take place,
with the above described improved arrangement there is always a free passage for
the escape of the gases and consequently the draught is in no way impeded.
Dated this 7th day of February 1891.
ABEL & IMRAY,
Agents for the Applicant.

page_text: Improvements in Ventilating Cowls.
I, JOHN BARTLETT, of No. 37, Cuthill Road, Camberwell, in the County of
Surrey, 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 :—
My invention relates to an improved construction of ventilating cowl, more
particularly applicable to gas lamps, but also applicable in all cases where
ventilators are used, whereby, while a free exit is allowed for the combustion
gases or vitiated air, the interior of the lamp or other space to be ventilated
is protected against down-draught or gusts of wind.
For this purpose I construct on the upper end of the ventilating pipe or flue
a chamber of rectangular or other suitable section, within which is a second
smaller chamber closed at top and having sides that slope slightly outwards
in the direction from the bottom to the top while at bottom it communicates
with the pipe or flue. In the sloping sides of the chamber are formed a
number of openings and to the upper edge of these openings are loosely hung
light tale flaps.
Owing to the outward sloping or overhanging position of the sides of the
chamber, these flaps, which hang vertically are under ordinary circumstances
somewhat removed from the openings, and the collective area of the free spaces
thus formed between the flaps and the edges of the openings is amply sufficient
to allow of the free escape of the combustion gases or vitiated air. On the
occurrence of a down draught or gusts of wind however, the outward pressure
of the air upon the tale flaps on one or more sides of the chamber will cause
them to close upon the openings and thus prevent the wind from penetrating
into the lamp flue, while the flaps on the side or sides of the chamber that are
not affected by the wind will still allow the free egress of the gases.
The outer chamber of the cowl has its top formed with an upward slope and a
central opening, the edge round such opening being formed with an outward
curvature while over the opening at a suitable distance therefrom is a sloping
cap. Thus the wind penetrating between the top of the chamber and the cap
will be deflected upward by the curved edge away from the opening.
The bottom of the space between the inner and outer chambers is provided with
small holes at its lowest points, through which can escape any water of condensation
or rain that may penetrate into the outer chamber, without penetrating into the
inner chamber.
It will be seen that the above described construction of ventilating chamber with
tale flaps will have the advantage over the ordinary construction of ventilators
with tale flaps, that whereas these are always made with their sides at such an
inward sloping angle that the flaps remain closed upon the opening thereof, so that
they have to be forced open by the air currents before any ventilation can take
place, with the above described improved arrangement there is always a free
passage for the escape of the gases and, consequently the draught is in no way
impeded.
The accompanying drawing shews the construction of my above described
improved ventilating cowl. Fig. 1 shews a vertical section, and Fig. 2 a sectional
plan.
The ventilating pipe A has its upper end enclosed in a chamber B, the sides of
which incline outwards and have openings C over which are loosely hung the tale
flaps D, which, in hanging vertically downwards are consequently slightly removed
from the openings C, leaving a free passage through them for the gases from the
flue pipe A. The chamber B is enclosed by a casing E which may be conveniently
secured by screws to a flange B' on the extended bottom of the chamber B. The

page_text: top of the casing has an opening F, the edge round which is formed with a curved lip
as shewn, and which is covered in by a cap G.
The space between the casing E and the chamber B is divided at the angles by
partitions H so as to form four separate compartments with which the four sets of
openings C on the four sides of the chamber respectively communicate.
From the above construction it will be seen that under ordinary circumstances,
all the flaps D being removed from their openings, a free ogress will be afforded for
the combustion gases or vitiated air through the openings into the surrounding
casing, and thence into the atmosphere, but on the occurrence of gusts of wind,
these, in penetrating to a certain extent into one or more compartments of the
space between the casing and the chamber, will cause the tale flaps on the corre-
sponding sides of the chamber B to close their openings, and the wind will thus be
prevented from entering the flue pipe A, while at the same time the flaps on those
sides of the chamber which are not affected by the wind will remain open, allowing
free egress to the gases or air.
The greater portion of the wind entering between the sloping top of the casing E
and the cap G, will be deflected away from the opening F by the curved lip, so as
to be prevented from entering the casing.
Although I prefer to employ the construction of my improved ventilating cowl
above described, I do not limit myself to the same, as it will be evident that the
form of the chamber B can be variously modified, so long as it is provided with one
or more sides inclining outwards, with openings having loosely hung tale flaps that
ordinarily hang away from the said openings, but which are made to close these on
being acted upon by a gust of wind.
Having now particularly described and ascertained the nature of this inven-
tion, and in what manner the same is to be performed, I declare that what
I claim is :-
1. A ventilating cowl wherein the discharge opening of the ventilating tube or
flue is enclosed by a chamber having one or more sides sloping outwards in which
are formed escape openings with loosely hung tale flaps that hang away from the
openings so as to leave these free for the escape of the gases, substantially as hercin
described.
2. In a ventilating cowl the combination of a chamber enclosing the discharge
opening of the ventilating flue having one or more sides inclining outwards, with
openings over which are hung tale flaps that hang away from the opening, and a
casing surrounding the said chamber so as to leave a space between the two, which
is divided by partitions into separate compartments, substantially as herein
described.
Dated this 22d day of March 1901
ABEL & IMRAY,
Agents for the Applicant.