AN IMPROVED VENTILATOR AND CHIMNEY POT
Year: 1878

page_text: LETTERS PATENT to George Ewart, Metal Worker, of 346, Euston Road,
London, for the Invention of "AN IMPROVED VENTILATOR AND CHIMNEY
POT."
PROVISIONAL SPECIFICATION left by the said George Ewart at the Office
of the Commissioners of Patents on the 26th November 1878.
GEORGE EWART, Metal Worker, of 346, Euston Road, London.
VENTILATOR AND CHIMNEY POT."
AN IMPROVED
Whereas there are already in use several kinds of apparatus designed to produce
an up current of air by means of revolving screws of different shapes, and also
several kinds of apparatus designed to prevent down blow, as well as quicken up
current by means of cones, rings, and fans fixed in different positions. Now, my
Invention consists in a method of combining both these systems in one apparatus.
The arrangement of fixed parts which I prefer is that of two cones with their
bases towards each other, but at a proper distance apart, the lower cone towards it's
apex being fitted with a socket of the size of the pipe on which the ventilator is to
be fixed, the upper either closed, or if open, then covered by a flat plate elevated
above the opening by means of rods; and the revolving apparatus which I find
most suitable is a series of spiral blades fixed at a proper angle to a central spindle,
or (when used for a chimney pot) to an inner ring; the outer parts of these blades
are connected with an external ring of sufficient diameter and depth to cover the
opening between the two cones above named at a proper distance from them. Fans
of a suitable shape are fixed to the outside of this ring, by means of which the
whole of the revolving portion, consisting of the ring and screw, is turned by the
wind. But when the screw is to be turned by mechanical power applied instead of
by the wind, then this outer ring may be fixed, and the fans would be unnecessary.

page_text: Though I have found this arrangement the best for the purpose, yet my Invention,
as before said, consists not in any particular shape of revolving screw, or of fixed
cones or fans, but in combining these two methods so as to obtain the advantages
of both in one and the same apparatus.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said George Ewart in the Great Seal Patent Office on the 10th June
1879.
.
GEORGE EWART, of 346, Euston Road, London, in the County of Middlesex, Zinc
Worker. "AN IMPROVED VENTILATOR AND CHIMNEY POT."
My improvement consists of a combination of two methods, one of which is already
in use for producing an upcurrent, and the other is designed with special reference
to the prevention of a downcurrent.
The apparatus for producing the upcurrent consists of a screw, archimedean or
other, revolving through the action of the wind or by power applied.
The apparatus for preventing the downblow consists by preference of an arrange-
ment of two cones, with their bases towards each other, but at some distance apart.
Outside the opening, between the bases of these cones, is a ring upon which fans are
fixed to catch the wind, and so cause the ring to revolve. On the inside of the ring
supports are fixed, connecting it with the screw aforenamed, which therefore revolves
with the wind also..
The revolution produces an upcurrent through any pipe or chimney on which it
may be fixed, while the arrangement of the cones and ring prevent downblow. As
to the apex of the upper cone, it may be either closed or open, but when open it is
covered by a flat plate supported by rods at a proper distance. This arrangement
of the screw and of the cones I have found the best for the purpose required, but
the Invention consists in arranging any form of revolving apparatus for the produc-
tion of updraught within any fixed apparatus now in use, or that may be hereafter
designed, for the purpose of preventing downblow or producing upcurrent.
Again, I apply my Invention by fixing a conical ring of proper size and inclina-
tion within a circle formed by a series of windfans, the effect of which is to prevent
the wind blowing down the pipe, round the top of which the windfans revolve.
Above the mouth of the conical ring, at a fitting distance, is placed a flat plate,
which prevents the wind from blowing down the mouth of the cone, and causes wind
blowing from any direction to pass over the mouth of the cone in a horizontal or
else in a slightly upward direction, so producing an upcurrent in addition to that
produced by the revolution of the windfans and screw. This conical ring, and also
the flat plate above the mouth thereof, may be either fixed separately from the wind-
fans, or may be attached to and revolve with them, and the revolving parts may be
either connected with a screw working inside the tube to increase the updraught, or
where this is objectionable (as it is when the apparatus is to be used for a chimney),

page_text: the screw can be left out, and the revolving part be entirely hung from the top.
This is a simple and effective method of applying the Invention, which is the com-
bining in one apparatus the use of parts which will produce when acted on by the
wind an upcurrent without revolution, along with parts which depend upon revo-
lution for producing this result. When the apparatus is to be used for the cure of
a smoky chimney, I propose to place the conical ring outside instead of inside the
windfans, so as to leave the centre clear right up to the flat plate.
.
In witness whereof, I, the said George Ewart, has hereunto set my hand
& seal, this Fifth day of June, in the year of our Lord One thousand eight
hundred and seventy nine.
GEORGE EWART. (L.S.)