An Improvement in and in connection with Ventilating Cowls and Chimney Cowls.
Year: 1889

page_text: Date of Application, 26th Apr., 1889
Complete Specification Left, 24th Jan., 1890-Accepted 29th Mar., 1890
PROVISIONAL SPECIFICATION.
An Improvement in and in connection with Ventilating Cowls
and Chimney Cowls.
1, JOHN SOWERBY MARTINDALE of 4 Newton Street Birkenhead in the County of
Chester, Builder and Contractor, do hereby declare the nature of this invention to
be as follows:-
The object of my Invention is to so construct a cowl or cap to protect or cover
any upcast ventilating shaft, chimney pipe or flue, or other opening to be so
protected, that while giving free space for the egress of air or smoke, no air or
water can possibly be injected into the opening or duct so covered. More particularly
is this object desirable in the case of cowls used on board ships for either ventilating
purposes or chimneys to stoves, as in rough weather at sea it is necessary to resort
to the dangerous expedient of covering up ventilators, to keep out water, the same is
the case with stove pipes, also in ordinary weather if a sail is set perpendicularly
over a chimney pipe, the wind filling the sail is deflected and driven down the pipe,
causing much annoyance and discomfort.
To effect this particular object I have considered a certain fixed law or force in nature,
as regards air being forced through an opening and projected against an obstacle set
obliquely to the current, the wind so intercepted is forced in a direct line to the
plane of the face of the obstacle and would so continue its course if the resistance
met were at a sufficiently oblique angle to deflect it, but if the resistance is met,
forming a right angle to the plane of its course an abrupt termination is caused and
the air is diffused.
Now, having this particular fact in view my Invention simply consists in supplying
and placing in position obstacles so as to protect the opening into the pipe and to
direct the course of the air or water passing over them in such manner as to absolutely
prevent either air or water being forced down the pipe.
I therefore provide a cone-shaped cover fixed above the mouth of the pipe leaving
free space for air or smoke to ascend, the sectional area of which is about twice that
of the pipe to be covered, the sides of this cone to the apex forming an angle of
45 degrees or thereabouts the base of the cone to be of sufficient diameter to
overhang the mouth of the pipe and to be sufficiently concave for the two purposes of
(1) to prevent water passing along the underside and falling into the pipe and (2) to
allow the brush head of a sweeper to pass through the pipe in case of its being used
as a chimney cowl.
On the exterior upper portion or top of pipe I fix a <shaped flange having the
lower section longer than the upper one and having a diameter at its extreme radius
equal to the base of the upper cone. 1 also provide an outer jacket or caseing
covering the whole of the upper cone and to a few inches below the cone shaped
flange on pipe, this caseing forming a free air passage open at both ends only and
parallel to the line of the upper cone and flange on pipe.
These several parts being fixed in position, air forced down from the top passes
through the passage so formed and is projected against the lower section of the outer
shell (the resisting obstacle) then deflected and carried clear through the opening at
the bottom, and in like manner, wind deflected and driven upwards from the plane
of a roof or forced by any other means through the lower opening of passage between
the pipe and caseing is carried through the aperture at the top.
To further control the action of the air passing through the bottom opening I fix
four feathers or brackets dividing the lower section of the radius into four compart-
ments, each bracket extending perpendicularly from top of internal pipe or flange to
the lower edge of outer caseing, the brackets having the two-fold use of (1) to

page_text: concentrate and to prevent an eddy by the air striking and being carried round the
pipe, (2) to fix and connect the outer shell to the pipe.
The annexed drawing with the accompanying description will the better explain the
nature of my Invention.
Figure 1 is a sectional elevation of the ventilating cowl or chimney cowl
arranged according to my Invention more particularly described in the foregoing
Specification.
Figure 2 is a plan of figure 1, shewing the diameter of the pipe or duct to be
protected, the letters on lines a. a. and b. b. in this figure also shew the projection of
the outer shell or jacket from the walls of pipe at the corresponding lines a. a. and b. b.
in figure 1.
The four lines dividing the radius of figure 2 at right angles shew the position of
the perpendicular feathers or brackets as are described in the specification, which
feathers commencing at the line a. a. and terminating at or below the line b. b. in
figure 1.
The arrows in the drawing indicate the passage of air when being forced through
from either the top or bottom of the cowl.
COMPLETE SPECIFICATION.
An Improvement in and in connection with Ventilating Cowls
and Chimney Cowls.
I, JOHN SOWERBY MARTINDALE of 4 Newton Street Birkenhead in the County of
Chester Builder and Contractor 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 my Invention is to so construct a cowl or cap to protect or cover any
upcast ventilating shaft chimney pipe or flue or other opening to be so protected that
while giving free space for the egress of air or smoke, no air or water can possibly
be injected into the opening or duct so covered. More particularly is this object
desirable in the case of cowls used on board ships for either ventilating purposes or
chimneys to stoves as in rough weather at sea it is necessary to resort to the
dangerous expedient of covering up ventilators to keep out water, the same is the
case with stove pipes, also in ordinary weather if a sail is set perpendicularly over
the pipe the wind filling the sail is deflected and driven down the pipe causing much
annoyance and discomfort.
To effect this particular object I have considered a certain fixed law or force in
nature as regards air being forced through an opening and projected against an
obstacle set obliquely to the current, the wind so intercepted is forced in a direct line
to the plane of the face of the obstacle and would so continue its course if the résistance
met were at a sufficiently oblique angle to deflect it, but if a resistance is met forming
a right angle to the plane of its course an abrupt termination is caused and the air is
diffused.
Now having this particular fact in view, my Invention simply consists in supplying
and placing in position obstacles so as to protect the opening into the pipe and to
direct the course of the air or water passing over them in such manner as to absolutely
prevent either air or water being forced down the pipe.
I therefore provide a cone shaped cover fixed above the mouth of the pipe leaving
free space for air or smoke to ascend, the sectional area of which is about twice that
of the pipe to be covered. The sides of this cone to the apex forming an angle of
45 degrees or there abouts the base of the cone to be of sufficient diameter to overhang
the mouth of the pipe and to be sufficiently concave for the two purposes of (1) to
prevent water passing along the underside and falling into the pipe, and (2) to allow
the brush head of a sweeper to pass through the pipe in case of its being used as a
chimney cowl.

page_text: Sheet 1. of the drawings was filed with the provisional specification.
Figure 1 is a sectional elevation of the ventilating cowl or chimney cowl
arranged according to my invention more particularly described in the foregoing
specification.
-
Figure 2 is a plan of figure 1 shewing the diameter of the pipe or duct to be
protected, the letters on lines a. a. and b. b. in this Figure also shew the projection of
the outer shell or jacket from the walls of the pipe and corresponding lines a. a.
and b. b. in Figure 1.
The four lines dividing the radius of Figure 2 at right angles shew the position of
the perpendicular feathers or brackets as are described in the specification which
feathers commence at the line a. a. and terminate at or below the line b. b. in
Figure 1.
The arrows in the Drawing indicate the passage of air when being forced through
from either the top or bottom of the cowl. Figure 3 is a full sized sectional elevation
of a cowl or cap with my improvement as applied and fixed to the glass chimneys of
lamps burning paraffin or other oils or gas, to prevent the flame being extinguished
by natural air in motion or by air set in motion by fans or other artificial means of
creating air, as in hot climates.
This arrangement will apply also as a means of protecting the lamps in use in the
roofs of railway or other carriages also as a ventilator in the compartments of railway
or other carriages.
Figure 4 is the sectional front elevation, Figure is the sectional side elevation and
Figure 6 is a plan of the same ventilator on line a. b. so constructed as to fix perpen-
dicularly to the face of a wall.
Having now particularly described and ascertained the nature of my Inven-
tion and in what manner the same is to be performed I declare that what I
claim is:
1. In up cast ventilating pipes or chimneys or other flues or openings the means
as set forth for preventing air or water passing therethrough essentially consists
in so placing cone shaped protectors above and below the opening to be protected
and by means of the outer shell or jacket (being in lines parallel to the said cones

page_text: and open at each end only) thereby leading the air or water clear of such opening
so protected.
2. The construction of cap or cowl substantially as set forth with reference to
Figure 3 of the Drawings hereto annexed.
3. The construction of ventilator substantially set forth with reference to Figures 4,5
and 6 of the drawings hereto annexed.
4. That the plan of construction of the ventilator or cowl may be varied to any
geometrical form provided that the lines of my improvement and arrangement of the
cone shaped protectors and outer jacket are adhered to.
DL: a dose of January 1890
J. S. MARTINDALE.