An Improved Exhaust Ventilator and Chimney Top.
Year: 1890

page_text: Date of Application, 20th Nov., 1890
Complete Specification Left, 19th Aug., 1891-Accepted, 19th Sept., 1891
PROVISIONAL SPECIFICATION.
An Improved Exhaust Ventilator and Chimney Top.
I, ARTHUR CHARLES SMITH of 25 Albert Terrace New Church Road,
Camberwell in the County of Surrey, Patentee, do hereby declare the nature of
this invention to be as follows:-
:-
This invention relates to improvements in the construction of ventilators and
chimney tops, so that a most effectual exhaust is created in the shaft or chimney
upon which they are fixed.
It is constructed of a number of deflecting guard plates sharply bent or curved,
on an oblique line to the diagonal of the plate, to an angle of about 90°, and made
of any suitable material.
To form a head or exhaust chamber, these bent guard plates are fixed at equal
distances around the upper part of the tube or shaft, in such a manner that they
overlap each other; the lower parts overlapping to the right, and the upper parts
to the left, or vice versa.
Spaces or openings are left between the guard plates to allow of the entrance
and exit of wind, with smoke and vitiated air. The guard plates are fixed in position
by their diagonal corners, the lower corners being fixed a short distance from the
top of the tube or shaft; and the upper corners are fixed to a connecting band, the
diameter of which is much smaller than that of the tube or shaft, fixed a suitable
distance above it, or they may in some instances be continued up to an apex.
By this arrangement the tube or shaft enters into the head about one third
the height of head, thereby preventing wind or rain from driving down the shaft.
To regulate the action of the wind entering the head between the guard plates a
slight turn upward may be made on the inside edge of guard plates.
The result of the above arrangement and construction is that the atmosphere
passing through the openings facing the wind into the head, is immediately drawn
out with the smoke or vitiated air, on the opposite side, by the outer air impinging
on the deflecting guard plates; thereby creating a continuous exhaust current up
the ventilating or chimney shaft.
On the ventilator a cap or covering plate is fixed a short distance above the top
ring or apex, and the chimney top may or may not have a cap.
The ends and edges of guard plates may be cut to any suitable ornamental
shape.
In the accompanying sheet of drawings
Fig. 1. is an elevation of a ventilator made according to this improved method;
Fig. 2. a plan shewing the method of overlapping the guard plates;
Fig. 3. shews a guard plate before bending; and
Fig. 4. a bent guard plate.
Similar letters of reference denote corresponding parts in all the figures.
Dated this 20th day of November 1890.

page_text: COMPLETE SPECIFICATION.
An Improved Exhaust Ventilator and Chimney Top.
I, ARTHUR CHARLES SMITH, of 258 Albert Road, Peckham, in the County
of Surrey, Patentee, 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 :-
This invention relates to improvements in the construction of ventilators and
chimney tops, and has for its object the production of apparatus which shall
induce powerful exhaust currents in the shafts or chimneys to which they are
applied.
A ventilator constructed according to this improved method is illustrated in the
drawings filed with the Provisional Specification, and consists of a number of guard
plates B. of the shape shown in Fig. 3., or of any other convenient form, bent on a
line F. F. (at any desired angle to the diagonal E. E. of the plate) to an angle of
about 90° as shown in Fig. 4. These plates may, instead of being sharply bent
as shown, be curved so as to obtain the requisite formation; and may be made in
any suitable material.
The bent guard plates B. are arranged around the upper part of the shaft A. in
such a manner that their edges overlap the lower parts overlapping to the left and
the upper parts to the right, or vice versa, as shown in Figs. 1 and 2.
Openings are left between the guard plates B. to allow of the entrance of wind,
and to provide for the exit of the same with smoke or vitiated air.
Each of the guard plates B. are fixed in position by two diagonally opposite
corners; the lower corners being attached to the shaft A. and the upper ones secured
to a connecting band C. supported above the top of the shaft. Instead of the plates B.
being fixed as shown they may be continued up to an apex, or be attached to a cone,
or to any other suitable device.
To prevent wind or rain driving down the ventilating shaft or chimney, the
shaft A. is made to enter the ventilator for a distance equal to about one third
of its height; and an annular space may be left between the ventilating shaft and
the shaft A.
To regulate the quantity of air entering, or for convenience of manufacture, the
edges of the guard plates may be turned up, or down, as may be desired.
The exhaust current set up by a ventilator constructed as herein described is
produced by the air which passes into the head through the openings facing the
wind, being immediately withdrawn, with the smoke or vitiated air, by suction
caused by the outer air impinging on the guard plates B. on the opposite side.
By this action a continuous outward current is maintained and back draught entirely
obviated.
When used for ventilating purposes the apparatus is supplied with a cap or
covering D. of any suitable design.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that
what I claim is :-
1. The use, in the construction of ventilators and chimney tops, of guard plates
as hereinbefore described and illustrated in Figs. 3 and 4. bent as shown or curved;
or their equivalent whether in one or more parts.
II. A ventilator or chimney top constructed of guard plates as hereinbefore
described and illustrated in the drawings, or any mere modification thereof.
Dated this 19th day of August 1891.
ARTHUR CHARLES SMITH.