IMPROVEMENTS IN VENTILATORS AND CHIMNEY EXHAUSTERS "
Year: 1883

page_text: LETTERS PATENT to Robert Alexander Hunter of 28 South King Street
Dublin Ireland for an Invention of "IMPROVEMENTS IN VENTILATORS AND
CHIMNEY EXHAUSTERS
"
PROVISIONAL SPECIFICATION left by the said Robert Alexander Hunter
at the Office of the Commissioners of Patents on the 28th March 1883.
ROBERT ALEXANDER HUNTER of 28 South King Street Dublin, Ireland "IM-
PROVEMENTS IN VENTILATORS AND CHIMNEY EXHAUSTERS
"
This invention has for its object improvements in ventilators and chimney
exhausters.
The ventilator which is very simple in its construction is illustrated by Figure 1
of the annexed drawings. It consists of a pipe a and deflecting plates b and c.
The pipe a projects up a short distance through the lower plate b. The wind
blowing in any direction causes a current between the plates b and c and this
carries with it the air from the pipe a whereby an upward draft is established.
I make the ventilator in pottery ware to be applied as a ventilating ridge tile.
Figure 2 illustrates the method. I sometimes apply an intermediate plate or plates
as illustrated by Figure 3.
By a like appliance I improve the draft in a chimney. As a chimney exhauster
it may be applied to a single flue. But by preference and especially in building
new houses I construct a shaft large enough to take the smoke of all the fires.
Immediately above the fire instead of taking the flue up single I turn it into the
main shaft which is surmounted with the exhauster.

page_text: by the said Robert Alexander Hunter in the Great Seal Patent Office on the
27th September 1883.
ROBERT ALEXANDER HUNTER of 28 South King Street, Dublin, Ireland IM-
PROVEMENTS IN VENTILATORS AND CHIMNEY EXHAUSTERS
"
This Invention has for its object improvements in ventilators and chimney
exhausters.
The ventilator which is very simple in its construction is illustrated by Figure 1
of the annexed drawings.
It consists of a pipe a and deflecting plates b and c. The pipe a projects up a
short distance through the lower plate b. The wind blowing in any direction
causes a current between the plates b and c and this carries with it the air from
the pipe a whereby an upward draft is established.
I make the ventilator in pottery ware to be applied as a ventilating ridge tile.
Figure 2 illustrates the method. I sometimes apply an intermediate plate or
plates as illustrated by Figure 3. By a like appliance I improve the draft in a
chimney. As a chimney exhauster it may be applied to a single flue. But by
preference and especially in building new houses I construct a shaft large enough
to take the smoke of all the fires. Immediately above the fire instead of taking
the flue up single I turn it into the main shaft which is surmounted with the
exhauster.
The pipe or tube a in Figure 1 leads to the place to be ventilated. Plate c acts
as a cover to the tube, and prevents a blow down. This plate is made slightly
concave to throw off the rain. The ventilator will work in any position provided
the ordinary wind can play on it. The principle on which it works is as follows.
The tube a being full of air which has no motion in itself, is acted on by the
ordinary air which is in motion. The slightest breeze in any direction, say from
directly over it (as represented in the Figure by arrows N° 4) passes down by the
sides of the deflecting plates and in its passage actually rubs away by friction the
air which is between the two plates in other words a partial vacuum is formed
which causes an induced current in the pipe. This air must be replaced with a
fresh supply which must come through the tube, and it is through this action I
secure complete ventilation.
When the wind blows in any other direction as say 5 or 7 it is deflected by the
plates and passes over the mouth of the tube which it also does if it blows from
point. N° 6. In all these cases the same end is gained viz the moving air exhausts
the stationary air which is in the tube, and consequently it must be replaced by
a new supply from the place to be ventilated.
The principle is in all cases the same. The advantage in the ridge tile is that it
can be fixed without trouble on any roof: it being made the same size as ordinary
ridge tiles, and fitted exactly in the same manner.
In all roofs at the ridge there is a space where the slating finishes against the
ridge. It is to cover this space ridge tiles are put on, and it is through this space
purpose to ventilate the rooms under. It is not necessary that the tube should
run down into the rooms below.
Immediately the ventilator begins to work it exhausts the air which is in the
roof and this must be replenished through a vent either in the ceiling or otherwise
connected with the rooms to be ventilated. There is no extra expense in setting
this tile more than if it was a common ridge tile.
I also use this exhauster as a chimney cowl or cap. It may be used on single
flues but I intend more particularly to use it as a common cowl to all the flues that
can be conveniently connected with it. In the case of new houses or chimneys I
propose to build a shaft large enough to take the smoke of all the fires connected

page_text: with it. Immediately above the fire instead of carrying the flue all the way up
(as is the custom). I turn it into the shaft, this shaft is the ventilating pipe and is
surmounted with the exhauster.
Figure 4 shows a section of an exhauster designed expressly for quick travelling
railway carriages or to be used on shipboard or in exposed places where the rain or
spray would find its way into the mouth of the vent pipe. The exhauster is
circular in plan and consists of a plate A which may be fixed to the ships deck,
carriage top or exposed building. Onto this plate is fixed a pipe B of any con-
venient height, surmounted by a cowl built up in rings as herein-after described.
The plate A also carries an inner shield the lower portion of which is a pipe C with
an external flange C'. Carried by distance pieces D is a cone E having a hole at
its apex and an external flange which supports a disc or cover plate F by means of
distance pieces F'.
By this arrangement annular openings are left for the escape of smoke or heated
air into the pipe B whence it passes up to the cowl. The cowl is built up in the
following manner; A plate G of the section shown having on its under side a
socket is slipped over the top of the pipe B-at a short distance above this plate is
a second plate G¹ supported by six distance tubes H and above this plate again is
a similar plate G². The plates G G G2 have a peculiar curved sectional form as
the drawing indicates. Above the plate G2 and supported by distance tubes is a
disc by preference slightly dished as shown this again is surmounted by a casting
carrying a finial I.
Bolts are passed through the plates G G¹ G² and distance tubes H these secure
the whole together into one compact and firm cowl having openings all round its
outer surface to allow the smoke or air to escape. It will be seen that should any
rain or spray pass into the cowl and down the pipe B it will fall onto the inner
shield and accumulate on the upper surface of the flange A from which it can
escape through the holes A¹.
Figure 5 shows partly in section a ventilator suitable for the ridge of a house
and Figure 6 is a plan of the same. The lower portion A is made of pottery ware
and of various angles to suit the pitch of different roofs. A circular hole enlarged
at the top passes up through its centre, and this is surmounted by a circular cast
iron plate B of the section shown. On the under side of the plate B is a foot
which is dropped into the hole in the ridge cap. Above this plate is a disc C, by
preference dished as shown carried by legs, on the lower end of these legs are pins
cast in, these are inserted into holes in the plate B and may be rivetted over, or
the plates may be attached together in any convenient manner. The disc carries
a casting to support a finial D the whole making an ornamental ventilating ridge
cap.
In all these ventilators are to be found the simple elements indicated in Figure 1
by the letters a b c. I have repeated these letters on the analogous parts in the
subsequent figures.
What I claim is my improved ventilators and chimney exhausters substantially
as described.
I also claim the combination in a ventilator or smoke exhauster of the parts a b
and c substantially as described.
In witness whereof I the said Robert Alexander Hunter have hereunto set my
hand and seal this Twenty fourth day of September in the year of our Lord One
thousand eight hundred and eighty three.
בד
RA HUNTER. (LS.)