Improvements in Cowls for Chis, Ventilating Shafts and the like.
Year: 1898

page_text: I, RICHARD SMITII, of 9, Albert Terrace, Whitehaven, in the County of Cumber-
land, Tinsmith, do hereby declare the nature of this invention to be as follows:-
My invention relates to improved cowls for inducing an updraught in chimneys,
ventilating shafts and the like.
According to my invention the shaft portion of the cowl has at its upper end
a conical cap and around it a series of longitudinal louvres or openings through
which the smoke can escape.
Surrounding the upper portion of the shaft is a shield composed of two cone
frustums secured together at their larger ends, the upper end of the said shield
being open, to allow the escape of the smoke, and at some distance above the top
of the shaft, whilst the opening in the lower end of the shield is of larger diameter
than the shaft so as to permit of the entrance of air; on the shield below this open
end is placed a deflector for directing the air into the hood. Around the hood
are formed indentations or recesses which at their upper ends open within the
hood in such a manner that the air which enters through these recesses will be
directed upwardly in the form of jets which operate in the same manner as the jet
of an injector for inducing an up current through the shaft. One, two or more
series of these recesses may be formed around the hood and are so arranged that
some of the said recesses will be presented to the wind from whatever direction it
may blow.
Although I have described my cowl as applied for preventing down draught in
chimneys it is to be understood that it can also be used for ventilating purposes.
Dated the 31st day of October 1898.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London,
Agents for the Applicant.
Improvements in Cowls for Chimneys, Ventilating Shafts and the like.
I, RICHARD SMITH, of 9, Albert Terrace, Whitehaven, in the County of Cumber-
land, Tinsmith, 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 improved cowls for inducing an updraught and prevent-
ing downdraught in chimneys, ventilating shafts and the like.

page_text: According to my invention the shaft portion of the c.,wl has at its upper end
a conical cap and around it a series of longitudinal louvres or openings through
which the smoke can escape.
Surrounding the upper portion of the shaft is a shield or hood composed of two
cone frustums secured together at their larger ends, and having in it a series of
recesses or indentations. On the shield below this open end is placed a deflector
for directing the air into the hood.
To enable my invention to be fully understood I will describe the same by
reference to the accompanying drawing, in which :-
Figure 1 is an elevation of my improved cowl:
Figure 2 is a vertical section of the same; and
Figure 3 is a horizontal section on the line 3-3 Figure 2.
a is the shaft of the cowl, b is the conical cap upon the upper end of the same
and c, care the openings formed in the upper end of the said shaft.
dis the hood which as herein before 'stated, is composed of two cone frustums
secured together at their larger ends or bases, the said hood being secured to the
shaft by any suitable means, for instance, by the wings e, e The upper end of
the hood is open to allow the escape of the smoke or air and is arranged at some
distance above the top of the shaft, whilst the opening at the lower end of the hood
is of larger diameter than the opening at the upper end so as to form a space f
around the shaft.
g, g are the recesses or indentations formed around the hood, which recesses or
indentations at their upper ends open within the hood in such a manner that the
air which enters through them will be directed upwardly in the form of jets and
operate for inducing an up current of air through the shaft and also, if a sudden
down-draught occur in the top of the hood, for allowing it to escape. One, two or
more series of these recesses may be formed around the hood and are so arranged
that some of them will be presented to the wind from whatever direction it may
blow.
In the drawings I have shewn two series of such recesses, the lower set being so
arranged that the jets of air do not pass in contact with the openings c, c in the shaft
whilst the upper set is arranged above the shaft so as to prevent a downdraught
getting through the openings c, c.
h is the deflector which is arranged around the shaft below the hood and the
inclined upper portion of which serves to direct the air impinging against it through
the space f around the bottom of the hood.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I claim
is:-
1. The improved cowl consisting of a vertical shaft closed at the top by a cap
and having around it near the top a series of openings, a hood surrounding the
upper portion of the said shaft and formed of two cone frustums placed base_to
base, a series of recessed openings being formed around the said hood, and a
deflector below the hood, substantially as described.
2. The manufacture and use of the improved cowl for chimneys, ventilating
shafts and the like, herein before described and illustrated in the accompanying
drawing. .
Dated the 10th day of January 189.9