An Improved Chimney Terminal or Cowl.
Year: 1890

page_text: Date of Application, 17th Mar., 1890
Complete Specification Left, 29th Apr., 1890-Accepted, 2nd Aug., 1890
PROVISIONAL SPECIFICATION.
An Improved Chimney Terminal or Cowl.
We THOMAS DAVIE of 14 New Square Brady Street Bethnal Green, E. London
in the County of Middlesex Engineer and ALAN GEORGE BOUTCHER of The Elms
Bourne End in the County of Buckinghamshire Gentleman do hereby declare the
nature of this invention to be as follows:-
Our invention relates to the construction of a chimney terminal or cowl so
contrived that the wind itself shall debar its entrance into the chimney, or shaft, on
the windward, or side against which it blows at the same time giving a free opening
from the chimney, or shaft, on the leeward side for the escape of the smoko, and other
gases. The tube or shaft of our chimney terminal, or cowl is either of rectangular
form throughout, or rectangular at one end changing to a round at the other. The
two sides of the rectangular, or upper ond of the tube or shaft. we extend upwards in
the form of isosceles triangles so that the base of these triangles are level with the top
of the front, and back, or two remaining sides of the tube or shaft.
We now form a light flat plate or door and secure to it an axis in such a position
that one half of the plate or door is about an inch longer than the sides of the
isosceles triangles and the width slightly less than that of the back or front of the
shaft or tube; the other half of the plate; or door being of an equal length but
from 20 per cent. to 30 per cent. wider.
We now place this plate; or door into the upper end of the tube, or shaft in a
vertical position the larger, and heavier end uppermost, and pass the axis through the
apexes of the two triangles on the sides of the tube or shaft.
It will now be seen that the upper portion of the plate, or door being larger than
tue lower portion, it therefore offers a greater resistance to the wind and is driven to
the leeward side, the lower and narrower portion at the same time comes to the wind-
ward side (the lower portion being longer than the sides of the isosceles triangles the
bottom edge comes in contact with the top part of the back or front of the tube or
shaft and is thus prevented from getting out of position) thus giving a free and
protected opening on the leeward side for the escape of the smoke and other gases.
We make our chimney terminal or cowl of zine iron or any other suitable metal
and also of terra cotta stoneware or any other such material; when these latter
materials are used the plate or door is made of metal.
Dated this 17th day of March 1800
THOMAS DAVIE.
ALAN GEORGE BOUTCHER.
COMPLETE SPECIFICATION.
An Improved Chimney Terminal or Cowl.
We, THOMAS DAVIE of 14 New Square, Brady Street Bethnal Green E. London
Engineer and ALAN GEORGE BOUTCHER of The Elmis Bourne End in the County
of Buckinghamshire Gentleman 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 :-
Our invention relates to the construction of a chimney terminal or cowl so
contrived that the wind itself shall debar its entrance into the chimney or shaft
on the windward or side against which it blows at the same time giving a free
opening from the chimney or shaft on the leeward side for the escape of the smoke
and other gases.
It is best described by aid of the accompanying drawings in which :-

page_text: Fig. 5 Plate or door.
Like letters are used for like parts in all drawings,
Referring more especially to Figs. to 4 D is the tube or shaft of our chimney
terminal or cowl which is either of rectangular form throughout or rectangular at
the upper end changing to a round at the lower end. Fig. I is the plan at the upper
and rectangular end of the tube or shaft D. The two sides B. B' of the tube or shaft
we extend upwards in the form of isosceles triangles as shown in Fig. 3 and 4 so
that the line of the base of these triangles is the same as the top edge of the front
and back, A. A' of the tube or shaft D.
In the apexes of the triangular sides we form at G small circular holes sufficiently
large to allow the axis E (which will be described hereafter) to move easily; we
strengthen these triangular sides with stiffening pieces M.
The
We now form a flat plate or door as shown in Fig. 5 and secure to it an axis E in
such a position that the portion F is about an inch longer than the distance
from G to H, the width being slightly less in size than the back or front A. A¹.
portion J is the same length as F and the width 25 per cent, more; to the upper end
of the portion J we secure a small roller N. We strengthen the plate or door by
securing to both sides of it stiffening pieces K as shown in Fig. 5.
We now place the plate or door (Fig. 5) into the upper end of the tube or shaft D
the larger end J being uppermost and we pass the axis E through the holes G in the
apexes of the two triangular ends of the sides of D.
Having now described the construction of the various parts of our chimney terminal
or cowl; it will be seen that although the cowl does not rotate the plate or door
(Fig. 5) which is hung on an axis E in the top of the tube or shaft D is regulated by
the direction and force of the wind. The portion J of the plate or door being larger
and consequently heavier than the portion F the wind has more power over it it
is therefore driven to the leeward side, the lower and smaller portion F at the same
time comes to the windward side (the portion F being longer than the distance
from G to H the bottom edge of comes into contact with the top edge of the
back or front of the tube or shaft D and is therefore kept within the said tube or
shaft D). By these means a free and protected opening is formed on the leeward side
for the escape of the smoke and other gases.
We construct our chimney terminal or cowl of zinc iron or any other suitable
metal and also of terra cotta stoneware or any other such material (when these latter
materials are used the plate or door is made of metal).
Having now particularly described and ascertained the nature of our said
Invention and in what manner the same is to be performed we declare that what we
claim is
1st. That downdraft is impossible.
2nd. That the sweeping of an ordinary chimney shaft with a common sweeps
machine can be continued through it without any obstruction whatever and without
any damage to or interference with its action.
3rd. That it can be made entirely of metal or of terra cotta earthenware or any
such material with a metal door.
4th. That it can be made in any size to suit any required chimney or shaft.
5th. That on account of its simplicity there is no chance of it getting out of order
or of its action being interfered with.
Dated this 29th day of April 1890.
THOMAS DAVIE.
ALAN GEORGE BOUTCHER.