Improvements in Heads or Cowls for Chimneys, Ventilating Shafts and the like
Year: 1897

page_text: Date of Application, 13th Jan., 1897
Complete Specification Left, 13th Oct., 1897-Accepted, 18th Dec., 1897
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PROVISIONAL SPECIFICATION.
Improvements in Heads or Cowls for Chimneys, Ventilating Shafts
and the like."
I, NEVILLE LYNN, of 42 Chalcot Crescent, N.W. in the county of Middlesex
Dramatic Publisher, do hereby declare the nature of this invention to be as
follows:-
My invention relates to improvements in heads or cowls for chimneys, ventilating
shafts and the like, and is designed to effectually prevent the occurrence of down
draughts, against which ordinary chimney pots are practically no protection.
My improved cowl or head comprises a pair of revolving casings formed of sheet
metal or other suitable material and cylindrical or otherwise as may be convenient.
One of these casings is arranged outside the other, the space or distance between them
being sufficient to admit of the smoke flowing freely around the inner casing. The
said casings are provided with vanes or other suitable means to cause them to adjust
themselves to changes in the direction of the wind and may be arranged to revolve
simultaneously in opposite directions for which purpose they can be geared together
by any suitable means. They are each provided with longitudinal openings or slots,
the gearing being so arranged that when the casings come to rest the openings in
one of them face a solid or continuous portion of the other casing. The casings may
however be so connected that the openings of one of them are always situated or
brought to rest on the opposite side of the head or cowl to the openings of the other
the openings being suitably disposed to admit of this.
In the case of a chimney, the smoke rising up into the inner casing passes out
through the openings thereof, and is then caused to flow circumferentially around or
partly around the space between the two casings to the openings in the outer casing
whence it passes into the atmosphere. The arrangement may be such that the
openings in the outer casing are always turned away from the wind, thus, obviating
any liability to the creation of a down draught in the chimney, ventilating shaft or
the like, owing to the wind blowing directly into them.
To further guard against such down draughts being caused by currents of air
moving in a vertical direction, the tops of the casings may be provided with, or
protected by, hollow covers of conical or other suitable form each having a set of
openings arranged opposite a solid portion of the other.
In the case of a ventilating shaft or the like the action is similar to that described,
the noxious or mephitic gases taking the place of the smoke in a chimney..
The disposition of the openings on opposite sides of the casings forming the head
or cowl, acts very effectually to prevent gusts of air entering the chimney or
ventilating shaft in rough or squally weather.
By the use of my improved heads or cowls upon a chimney, smoking from down
draught or other cause is wholly or almost wholly obviated.
Such heads or cowls can be made extremely light and strong and can be applied at
trifling cost to existing chimneys, ventilating shafts or the like. They compar

page_text: favourably moreover both in durability and safety with devices at present in use for
preventing smoking or down-draught.
Dated this 13th day of January 1897.
HASELTINE LAKE & Co.
45 Southampton Buildings, London, W.C. Agents for the Applicant.
"Improvements in Heads or Cowls for Chimneys, Ventilating Shafts
and the like."
I, NEVILLE LYNN, of 42 Chalcot Crescent, N.W, in the County of Middlesex,
Dramatic Publisher, 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 improvements in heads or cowls for chimneys, ventilating
shafts, and the like, and is designed to effectually prevent the occurrence of down
draughts, against which ordinary chimney pots are practically no protection.
My improved cowl or head comprises an inner and an outer casing, each provided
with openings so situated that those of one casing face a solid or continuous portion
of the other casing.
Means are. provided to cause the opening or openings of the outer casing to be
always turned away from the wind, and the arrangement is such that the sinoke
or mephitic gases ascending the chimney or ventilating shaft pass into the inner
casing, thence into the space between the casings, and finally escape through the
openings in the outer casing.
In order that my invention may be clearly understood and readily carried into
effect, I will proceed to describe the same by aid of the accompanying drawings in
which
Figures 1 and 2 are elevations of one construction of my improved ventilating
cowl, at right angles to each other.
Figure 3 is a horizontal section thereof on the line x x Figure 1.
Figure 4 is a vertical central section on the line y y Figure 3.
Figures 5 and are detail views hereinafter referred to.
a represents the upper end of a chimney or ventilating shaft, and bare the inner
and outer casings of the cowl, the end of the chimney a fitting loosely in the lower
end of the inner casing. 62 63 are the openings in the said casings, which it will be
seen are arranged on opposite sides of the cowl; the outer opening 63 being, if desired,
provided with grate bars 64. These grate bars may be formed of flat strips of metal
bent upwardly at the parts 65, so that they act to deflect and break up any gusts of
wind that may strike the opening b³. Cheeks or lugs 66 may also be provided at each
side of the hole 63 for the same purpose. c.c¹ are plates which serve respectively to
close the upper and lower ends of the annular space between the casings. d is a
hollow conical cover for the cowl, and e el are vanes for causing it to turn with the
wind. is a pivot rod on which the cowl is supported in the ordinary manner, this
rod being carried by arms f', f2 rivetted or otherwise secured in the upper part of the
chimney and passing through an aperture f³ in the cover c'.
The action of my improved chimney cowl is as follows. Assuming a to be a
chimney, the smoke passing up the same will enter the casing b and flow through
the opening or openings 62 into the space between the inner and outer casing. It
will then flow around the said space and make its exit from the opening b³, as
indicated by the arrows.

page_text: The said opening 63 will, in the construction of cowl shown, always turn away from
the wind, as it is situated immediately between the vanes e e'. The bars 64 and
cheeks 6, will moreover, as stated, effectually break up any gusts of wind that
may strike the opening, thus rendering it practically impossible for down draughts to
occur.
In the case of a ventilating shaft the action of the cowl is precisely similar to that
herein before referred to, the noxious or mephitic gases following the same path as
that before indicated for the smoke.
Although I have shewn in the drawings a cowl having a single unperforated coverd,
yet I may in some cases provide the same with a double cover, the parts of which
have openings arranged on opposite sides of the cowl after the manner of the
openings 62 63. Moreover, although I have described the cowl as a revolving one, yet
I may apply my invention to stationary and other vaneless cowls by constructing
the same with an inner and outer casing similar to those of the cowl illustrated.
By the employment of my improved cowls upon a chimney, smoking from down
draught or other cause is wholly or almost wholly obviated, while the action is in
every respect as free and satisfactory as that of ordinary chimneys.
My improved heads or cowls can be made extremely light and strong and can be
applied at trifling cost to the ordinary chimney pots of existing chimneys to
ventilating shafts, and the like. They compare favourably moreover both in
durability and safety with devices at present in use for preventing smoking or down
draught.
In conclusion, I would state that although I indicated in my provisional
specification an arrangement in which the inner and outer casings bb1 are geared
together, yet I find in practice that it is more satisfactory to connect them rigidly
together as shown.
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. A head or cowl for a chimney, ventilating shaft, or the like, having an inner
and outer casing provided with openings arranged on opposite sides of the cowl,
substantially as described and for the purpose specified.
2. A head or cowl for a chimney, ventilating shaft, or the like, constructed
substantially as hereinhefore described with reference to the accompanying drawings.
1000+
HASELTINE LAKE & Co.
45, Southampton Buildings, London, W,C Agents for the Applicant.