Improvements in the Construction of Smoke Extractors, Exhausters, Ventilators, and the like.
Year: 1888

page_text: Date of Application, 14th Dec., 1888
Complete Specification Left, 14th Sept., 1889-Accepted, 26th Oct.,
1889
PROVISIONAL SPECIFICATION.
Improvements in the Construction of Smoke Extractors, Exhausters,
Ventilators, and the like.
We EDWIN SYDNEY STRANGE of 21 London Road, Tunbridge Wells, in the County
of Kent, Decorator and Plumber, and JOHN CLAYTON AUSTEN, of 10 St. Stephen's
Cottages, Tunbridge Wells aforesaid, do hereby declare the nature of this invention to
be as follows:—
The object of this invention is to construct smoke extractors, exhaust ventilators
and the like, in such a manner that a constant up-draught is produced even when there
is little or no wind.
According to this invention, we construct the smoke extractor, exhaust ventilator,
and the like, with a central tube surrounded by a partly perforated outer case, to
which it is secured by transverse open frames or ribs. The said onter case extends
above and below the central tube and if desired is provided with an over-hanging open
roof supported by two or more arms attached to the side of the outer case to prevent
rain or wind passing down the shaft or chimney.
Just above the top of the central tube, the outer case is constructed with an
inwardly projecting shoulder; the wind or air passing through the perforations in
the outer case, and rising therein, is deflected by this shoulder, so as to pass across
and above the outer edge of the central tube, and cause a suction of the smoke, or
vitiated air therein.
COMPLETE SPECIFICATION.
Improvements in the Construction of Smoke Extractors, Exhausters,
Ventilators, and the like.
Wo, EDWIN SYDNEY STRANGE, of 21 London Road, Tunbridge Wells, in the
County of Kent, Decorator and Plumber, and JOHN CLAYTON AUSTEN, of 10 St.
Stephens Cottages, Tunbridge Wells, aforesaid, 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 this invention is to construct smoke extractors, exhaust ventilators
and the like in such a manner that a constant up-draught is produced even when there
is little or no wind.
According to this invention we construct the smoke extractor, exhaust ventilator
and the like with a central tube surrounded by a partly perforated outer case to which
it is secured by transverse open frames or ribs. The said outer case extends above
and below the central tube and if desired is provided with an overhanging open roof
supported by two or more arms attached to the side of the outer case to prevent rain
or wind passing down the shaft or chimney. The outer case is constructed with an
inwardly projecting shoulder; the wind or air passing through the perforations in
the outer case and rising therein is deflected by this shoulder, so as to pass across
and above the outer edge of the central tube, and cause a suction of the smoke or
vitiated air therein.
And in order that our invention may be more fully understood and carried into
practice, we will now proceed to describe the same with reference to the accompanying
drawings in which similar letters indicate corresponding parts throughout.

page_text: Figure 1 is a vertical section of our invention; Figure 2 is a view of the central
tube; Figure 3 shows the upper part, and Figure 4 shows the lower part of the outer
case.
The central tube A is provided with an enlarged neck B on to the lower and
larger end of which is brazed, soldered or otherwise affixed the extension tube C. At
the junction between the neck B and extension tube C wo solder, braze or otherwise
rigidly affix the hollow inverted frustrum D provided with any suitable number of
perforations E for the admission of air or wind. The upper part of the outer case
is provided with a bell mouth F equal in shape and diameter to the base of the
frustrum D to which it is rigidly affixed along the edges J J as shewn in Figure 1.
The upper part of the outer case is also provided with an inwardly projecting
shoulder or baffle G, and, if desired, with an overhanging roof H. The lower
part of the outer case is provided with an enlarged neck K with perforations L L
for the admission of air. The top edge of the neck K is soldered, brazed or
otherwise affixed to the outside of the frustrum D as shewn in Figure 1. In some
cases this lower part of the outer case may be dispensed with.
The action of the apparatus is as follows:- The air or wind passes in through
the perforations and rises within the outer case outside the central tube A and is
deflected by the shoulder or baffle G so as to play against the top outer edge of
the central tube as indicated by the arrows in Figure 1. This action causes a
powerful induced current which rapidly exhausts the smoke and foul air from the
central tube which in its turn causes a powerful up-draught in the shaft or chimney
to which the invention is attached.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
A smoke extractor, exhaustor, ventilator and the like, consisting of a central
tube A with enlargement B and extension C combined with the perforated inverted
frustrum D and outer case with baffles F and Gand with or without the lower part
illustrated in Figuro 4, all constructed substantially in the manner and for the
purpose herein before set forth and illustrated in the accompanying drawings.
Data: 14th Jove of Santamban 1980
CASTLE SMITH,
Per F. W. Golby,
"Invention " Office, 54, Fleet Street, London, E.C., Agent for the Applicant.