Improvements in Wind-directed Cowls for Chimney and Ventilating Shaft Tops.
Year: 1889

page_text: Date of Application, 4th Dec., 1889
Complete Specification Left, 17th Apr., 1890-Accepted, 24th May, 1890
...
PROVISIONAL SPECIFICATION.
Improvements in Wind-directed Cowls for Chimney and
Ventilating Shaft Tops.
I, MICHAEL MOORE, of No. 3 Regent Street, South Shields, in the County of
Durham, Engineer, do hereby declare the nature of this invention to her as
follows:
'
My invention is specially applicable to the prevention of down draft in chimneys of
dwelling houses or other buildings but will be found very effective as a ventilator in
all cases where it is desired to establish an upward current to draw off heated or
impure air as for instance in dwelling houses, public buildings, warehouses, cellars,
ships holds, or cabins, or public vehicles.
It comprises essentially an inner T shaped cylindrical chamber the vertical leg of
which joins the top of the chimney, or of the ventilating shaft, and the horizontal
head of which is closed at. one end and open at the other and, preferably, tapered
from a larger diameter at the open. end to a smaller diameter at the closed end
which: then tapers to a point. Around this inner chamber is formed an outer chamber
of greater diameters at the ends, an annular space being thus formed between them,
and this outer chamber is open at both ends and has fixed upon it a wind vane
arranged to turn the "cowl" consisting of the inner and outer chambers, so that the
wind shall always blow against the pointed end of the inner chamber and pass through
the annular space between the two chambers. In order that the "cowl" may turn
freely, and adjust itself immediately to the slightest variation of the direction of the
wind, I propose to mount it upon a vertical spindle the point of which enters a
cylindrical box fixed to the top of the inner chamber and containing glass or other
balls, and upon this spindle the "cowl" revolves, practically without friction, through
the intervention of the balls which are protected from soot or dirt by a cap which also
secures them in their place.
+
The current of wind blowing against the pointed end of the inner chamber is diverted
into the annular space between the two and issues from the opposite end with sufficient
force to cause, by suction, an upcast current in the inner chamber sufficient to counter-
act any tendency of the smoke to return caused by back currents. Similarly, in the
case of ventilators, the induced upcast current is strong enough to carry off heated..
or impure air from buildings and when applied to ships or to public vehicles in motion
it will be still more powerful.
The cowls may be made of any suitable material such as sheet iron or steel
galvanised or otherwise or of brass or copper in some instances.
.
Doted thin' ith dan of Darambon 1940
T. J. DANSON,
Per L. W.,
COMPLETE SPECIFICATION.
Improvements in Wind-directed Cowls for Chimney and
Ventilating Shaft Tops.
I, MICHAEL MOORE, of No. 3 Regent Street, South Shields in the County of
Durham Engineer do hereby declare the, nature of said invention; and, in what
manner the same is to be, performed to be particularly described; and ascertained in
and by the following statement :-
: If t
i
My invention' is specially applicable to the prevention of down draft in chimneys
of dwelling houses or other: buildings but will be found very effective as a
ventilator in all cases where it is desired to establish an upward current to draw off

page_text: heated or impure air as for instance in dwelling houses, public buildings, warehouses,
cellars, ships holds or cabins, or public vehicles.
It comprises essentially an inner T shaped cylindrical chamber the vertical leg of
which joins the top of the chimney or of the ventilating shaft, and the horizontal
head of which is closed at one end and open at the other and preferably tapered from
a larger diameter at the open end to a smaller diameter at the closed end which
then tapers to a point. Around this inner chamber is formed an outer chamber
of greater diameters at the ends, an annular space being thus formed between them
and this outer chamber is open at both ends and has fixed upon it a wind vane
arranged to turn the "cowl," consisting of the inner and outer chamber so that the
wind shall always blow against the pointed end of the inner chamber and pass through
the annular space between the two chambers. In order that the "cowl" may turn
freely, and adjust itself immediately to the slightest variation of the direction of
the wind, I propose to mount it upon a vertical spindle the point of which enters
a cylindrical box fixed to the top of the inner chamber and containing glass or
other balls, and upon the spindle the cowl revolves, practically without friction
through the intervention of the balls which are protected from soot or dirt by a cap
or gland which also secures thein in their place.
The. current of wind blowing against the pointed end of the inner chamber is
.diverted into the annular space between the two and issues from the opposite end
with sufficient force to cause, by suction an upcast current in the inner chamber
sufficient to counteract any tendency of the smoke to return caused by back currents.
Similarly in the case of ventilators the induced upcast current is strong enough to
carry off heated or impure air from buildings and when applied to ships or to public
vehicles in motion it will be still more powerful.
In order to prevent a down draught by a sudden change in the direction of the
wind, as will sometimes occur in stormy weather I propose to fit the conical end of
the inner chamber so as to form a balanced hinged door which will automatically open
to allow the wind to pass out instead of down the chimney and then close.
In practical application as a chimney cowl I have found in some exceptional cases,
as where the chimney is adjacent to a much bigher building, to provide at the outlet
of the outer chamber a light hinged door the opening of which may be adjusted by a
chain in such a way that it will automatically close against a strong back current and
reopen when the back current ceases and this door may be so connected with the
hinged cone door as to open it when closing (and vice versa) so as to provide an outlet
for the smoke and heated air.
The cowls may be made of any suitable material such as sheet iron or steel
galvanised or otherwise or of brass or copper in some instances.
DESCRIPTION OF DRAWINGS.
On the accompanying sheet of drawings I illustrate my invention in the form of a
cowl to prevent down draft and smoking of chimneys Fig. 1 being a vertical
section and Fig. 2 an end elevation looking toward the mouths of the cowl.
The vertical leg A is secured to the top of the chimney brickwork and has rivetted
to it a spindle D upon which revolves the inner chamber B and the outer chamber C
turning in the direction of the wind by the vane V. The upper end of the spindle D
enters the mouth of a box E in which are the two balls F retained in their place by
the gland G the box E being bolted through the two chambers by studs S. The cowl
is secured to the spindle D by a flange or horn H on the box E which coming against
a key K through the spindle, prevents the cowl being carried away by the wind. The
cowl with its fittings are exactly balanced so that the centre of gravity is on the centre
of the spindle and this may by readily adjusted by weighting the back end of the outer
chamber as shown at W. The cowl is further steadied in revolving by a ring of
leather L around the mouth of the fixed vertical leg A over which ring the lower
part of the cowl B fits freely. The hinged cone shaped end is shewn closed which is
its normal position-in which it is retained by the counterweight-and in dotted lines

page_text: 18 shewn opened by the pressure of a reverse current of wind blowing in at the outlet
mouth. The full arrows indicate the direction of the wind and the dotted arrows that
of the smoke and heated air.
As previously mentioned for special cases I fit the light hinged door N shewn by
dotted lines to the outlet mouth of the outer chamber adjusted as to the extent of
opening by a chain O on a hook P. The effect of a strong back current of wind is to
close this door until this current has subsided when it will again open but this fitting,
as previously explained, is not required except in the case of a chimney very
unfavourably situated relatively to some adjacent very high building I propose in
some cases to connect the hinged door N with the hinged conical end M of inner
chamber B by light rods which will cause the two doors to act together the closing
of N opening M and vice versa.
The spindle D is cranked as shewn to allow of the sweeping brush passing right up
into the cowl.
When applied as a ventilator the cowl may either be wind directed by the vane or
the vane may be dispensed with and the cowl turned into position by hand. In the
case of railway carriages the rapid motion through the air will immediately turn the
cowl by the vane into the proper position to cause it to act with the greatest efficiency.
I do not restrict myself to details of construction nor to the proportions of the various
parts but the drawing shews my invention in a form which I have found to work very
efficiently in many cowls I have fitted.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed 1 declare that what I
claim is :-
1st. The construction and application of wind directed chimney or ventilator cowls
consisting of an inner chamber for the smoke or heated air closed at one end to a
conical point which may be hinged so as to open by the action of a back current and
surrounded by an outer chamber open at both ends the wind passing through the
space between the two chambers with increasing velocity from the inlet to the outlet
end substantially as described and shewn.
2nd. In combination with such chimney or ventilator cowls, for the purpose of
causing them to revolve with the least possible friction and without noise mounting
the cowl upon a spindle by intervening balls free to revolve one of which rests upon
the spindle substantially as described and shewn.
3rd. In combination with such chimney cowls or ventilators, to meet special cases,
the application of a hinged door to the outlet mouths closing against a back current
and opening again automatically which hinged door may be connected with the
hinged conical end in such a manner that in closing it will open and in opening will
close it substantially as described and in part shown.
4th. The improved wind directed cowl for chimney or ventilator comprising the
various parts in combination constructed and operating substantially as described and
shown
T. J. DANSUN, F.J.P.A.,
2, St. Nicholas' Buildings, Newcastle-upon-Tyne, Agent for Applicant.