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

page_text: PROVISIONAL SPECIFICATION.
Improvements in Cowls for Chimneys, Ventilating Shafts, and
the like.
I, STANLEY HATCH PAGE, of 2, Queens Street, Ramsgate, in the County of Kent,
Surveyor, do hereby declare the nature of this invention to be as follows:-
The object of this invention is to provide a cowl of such form that the action of
wind may more effectually than heretofore operate to draw out the smoke, air, or
gases from the chimney ventilating shaft or the like on which the cowl is placed.
The improved cowl comprises two or more truncated conical rings placed one above
the other with an interval between them, their axes coinciding with each other and
with the axis of the chimney or shaft at its mouth. These cones are open at the
base and towards their apices and are of larger diameter at both openings than the
interior diameter of the chimney shafts, the upper opening of the upper cone being
also wider than the upper opening of the lower cone.
Over the upper cone is a plate which is lower in the centre than at the
circumference; it may for instance be of the form of part of a sphere. The
diameter of this plate is greater than the diameter of the upper opening in
the upper cone, over which cone the said plate is fixed at a suitable interval.
From the upper opening of the lower cone a cylindrical sleeve of the same
diameter as this opening, extends downwards to embrace and secure the cowl upon
the chimney pot or otherwise on the chimney or shaft.
Improvements in Cowls for Chimneys, Ventilating Shafts, and
the like.
I, STANLEY HATCH PAGE, of 2 Queens Street, Ramsgate, in the County of Kent,
Surveyor, 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:-
The object of this invention is to provide a cowl of such form that the action of
wind may more effectually than heretofore operate to draw out the smoke, air, or
gases from the chimney, ventilating shaft, or the like, on which the cowl is placed.
The improved cowl comprises two or more truncated conical rings placed one
above the other with an interval between them their axes coinciding with each other
and with the axis of the chimney, or shaft at its mouth, the interval between the

page_text: said cones being open at the base, and the upper opening of the upper cone being
also wider than the upper opening of the lower cone in about the proportion
of 5 to 4.
Over the upper cone is a plate, which is lower in the centre than at the
circumference, it may for instance be of the form of part of a sphere. The diameter
of this plate greater than the diameter of the upper opening in the upper cone
(preferably in the proportion of 42 to 25) over which cone the said plate is fixed at
a suitable interval.
In constructing this cowl it is desirable also to use the following proportions, the
width of surface of the lower cone equal to the diameter of its upper open end; the
width of surface of the upper cone to the width of surface of the lower cone as
7 to 10. The diameter of the two cones at their bases to be equal, and equal also to
the diameter of the plate. The width of separation from the rim of the plate to the
base of the upper cone equals the width of surface of the lower cone, the width of
separation from the base of the upper cone to the base of the lower cone equals the
width of surface of the upper cone. The amount of depression of the centre of the
plate below the level of its rims will be to its diameter as 5 to 42.
From the upper opening of the lower cone a cylindrical sleeve of the same diameter
as this opening, extends downwards to secure the cowl to the chimney pot or
otherwise on the chimney or shaft.
This cone is shown in section in the annexed drawing in which a is the cylindrical
sleeve, b the lower cone, c the upper cone, and d the plate. e, e, are stays for
holding these parts together, f is a drain pipe for the plate d. The method shown
of fixing the stays is not essential to the invention.
Having now particularly described and ascertained the nature of this
invention and in what manner the same is to be performed I declare that what I
claim is:
A cowl comprising two truncated cones and a centrally depressed or downwardly
bellied plate, the upper opening of the upper cone being larger than the upper
opening of the lower cone, and the several aforesaid parts, being combined in the
relative positions and proportioned substantially as set forth.
Dated this 21st day of October 1807
Dated this 21st da
st day
of October 1807
HERBERT HADDAN & Co.,
Agents to Applicant,
18, Buckingham Street, Strand, W.C., London.