Improvements in Air Extractors, also Applicable as Chimney Cowls.
Year: 1886

page_text: Date of Application, 1st Apr., 1886.
Complete Left, 1st Jan., 1887.
Complete Accepted, 1st Feb., 1887.
::
I ANTHONY ROBINSON HARDING of the firm of the " Harding Ventilating
Company, of 27 Torrington Square in the County of Middlesex, Engineer do hereby
declare the nature of this invention to be as follows:-
My improvements have reference to the means employed for extracting or with-
drawing heated or vitiated air from rooms and applicable also as a chimney cowl.
According to my invention I attach to the outer end of a tube of any suitable
diameter a hollow ball of zine or other sheet metal, communicating with the air tube
and divided into two parts across the centre, thus forming two hemispheres. The
edges of each hemisphere being curved outwardly are retained apart by a metallic
ring surrounding the space between the hemispheres and at such a distance therefrom
as not to impede the passage of air. The external air impinging upon the exterior of
the above mentioned hemispheres and ring in any direction, creates an induced current
up the vertical tube thereby drawing the vitiated air or smoke from the room or
chimney and expelling it through the space between the hemispheres.
BREWER & SON,
For the Applicant.
Improvements in Air Extractors, also Applicable as Chimney Cowls.
1, ANTHONY ROBINSON HARDING of the firm of the Harding Ventilating Company
of 27 Torrington Square, in the County of Middlesex, Engineer, do hereby declare
the nature of the said invention and in what manner the same is to be performed to
be particularly described and ascertained in and by the following statement :-
My improvements have reference to the means employed for withdrawing or
extracting heated or vitiated air from rooms and other places, and such invention may
be also used as a chimney cowl.

page_text: DESCRIPTION OF DRAWINGS.
Fig. 1 is a transverse section and Fig. 2 a plan shewing vertical application of my
apparatus for extracting air. Fig. 3 a transverse section of same applied in a
horizontal position. Figs. 4 and are respectively a part transverse section and plan
of my apparatus as applied to a chimney cowl.
In all these arrangements corresponding paris are marked with corresponding
letters.
To the outer end of a tube A of any suitable diameter I attach a cap or top of hollow
ball like shape, divided across the centre into two parts B and C, thus forming two
hemispheres.
The edges of each hemisphere B and C are curved outwards as shewn at D and E
and are retained apart by metallic ring F and connected thereto by metal pieces G.
This metal ring F is placed at such a distance from the hemisphères as not to impede
the passage of air.
The external air impinging upon the exterior of the abovementioned hemispheres B
and and ring F in any direction creates an induced current up the vertical tube A
drawing the vitiated air from the room, or smoke from the chimney, and expelling it.
through the space between the hemispheres B and C and ring F.
When the extractor is used in a vertical direction I prefer to extend the metal
tube A upwards within the hemisphere B as shewn at A' Fig. 1, this having the effect
of making the extractor perfectly watertight, but when used as a chimney cowl or in a
horizontal direction as shewn at Figs. 3 and 4 such extension of the tube A is
unnecessary.
As a chimney cowl the lower part of the tube A Fig. 4 may be made any desired
form to suit the position or place to which it is to be applied, also the upper
hemisphere may be inade to lift and slide up the rods H for sweeping or cleansing
purposes.
Instead of the extractor being circular as shewn it may be of an oval or elongated
form.
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 1 claim is :-
1st. The arrangement and application of the hemispheres B and C in combination
with the outer ring F, and applied to tube A. of any desired form, for the purpose of
extracting air or smoke from rooms or chimneys, operating substantially as herein set
forth.
2nd. In air extractors and chimney cowls, the hemispheres B, C, and ring F
substantially as and for the purposes set forth together with any mere modification or
modifications thereof.
A. R. HARDING.