IMPROVEMENTS IN OR CONNECTED WITH CHIMNEY COWLS AND VENTILATORS
Year: 1883

page_text: LETTERS PATENT to George Davis, Iron Merchant, of Aberystwith, in the
County of Cardigan, Wales, William Jones, Cabinet Maker, of Llannon, in the
same County, and Robert Girdwood, Merchant, of Edinburgh, in the county of
Mid Lothian, North Britain, for an Invention of "IMPROVEMENTS IN OR
PROVISIONAL SPECIFICATION left by the said George Davis, William
Jones, and Robert Girdwood at the Office of the Commissioners of Patents on
the 15th January 1883.
GEORGE DAVIS, Iron Merchant, of Aberystwith, in the County of Cardigan,
Wales, WILLIAM JONES, Cabinet Maker, of Llannon, in the same County, and
ROBERT GIRDWOOD Merchant, of Edinburgh, in the County of Mid Lothian,
North Britain, IMPROVEMENTS IN OR CONNECTED WITH CHIMNEY COWLS AND
VENTILATORS
"
This Invention has for its object to improve the construction and action of
chimney cowls and ventilators; and it consists principally in taking advantage in
an improved manner of external currents of air by means of rotating or fixed
cowls or inducting hoods or funnels placed outside of any building or structure
from the interior of which smoke or gases or air is to be removed.
In one modification of the improved apparatus applicable to a chimney or to a
vertical ventilating passage, a cowl is arranged so as to rotate by the action of
wind or external currents, but with the vane by means of which it turns placed so
as to keep the mouth or opening facing the current. The mouth is by preference
of a conical or flaring form, and the inner part of the cowl is made to communicate
with a pipe or passage acting as an inverted syphon, the air which enters the cowl
first passing vertically downwards a convenient distance, and then proceeding
through a curved or bent part of the pipe or passage so as to issue from the
terininal orifice of the pipe in an upward direction or in the direction in which the
smoke or gas or air passes along the flue or duct through which it is discharged.
In this way a jet of air, the force of which corresponds to that of the external

page_text: current is made to act on the smoke or gas or air in the direction for expelling it.
The air-inducing cowl may be fitted to the top of a chimney or chimney can the
syphon pipe being placed entirely inside the flue, and suitable outlet openings being
provided for the smoke.
In other modifications the air-inducing cowl and siphon pipe are placed outside
of the chimney or ventilating outlet and either near thereto or at any convenient
distance, and the jet end of the siphon pipe is inserted through the side into the
flue or passage. A single air-inducing cowl may be arranged to supply jets to two
or more flues or passages the siphon pipe or its lower part being provided with
branch pipes for the several flues or passages.
In other modifications the air-inducing cowl is stationary and is formed with a
number of conical or flaring mouths or openings facing different ways so that in
whatever direction the external current may be it will have an opening facing it.
The several openings cominunicate with separate or distinct passages which extend
sufficiently down the siphon pipe to prevent the air entering at one opening from
passing out at another of the openings.
SPECIFICATION in pursuance of the conditions of the Letters Patent_filed
by the said George Davis, William Jones and Robert Girdwood in the Great
Seal Patent Office on the 11th July 1883.
GEORGE DAVIS, Iron Merchant, of Aberystwith, in the County of Cardigan,
Wales, WILLIAM JONES, Cabinet Maker, of Llanon, in the same County, and
ROBERT GIRDWOOD, Merchant of Edinburgh, in the County of Mid Lothian,
North Britain. "IMPROVEMENTS IN OR CONNECTED WITH CHIMNEY COWLS AND
VENTILATORS
"
Our said Invention has for its object to improve the construction and action of
chimney cowls and ventilators; and it consists principally in taking advantage in
an improved manner of external currents of air by means of rotating or fixed cowls
or inducting hoods or funnels, placed outside of any building or structure from the
interior of which smoke or gases or air is to be removed.
In one modification of our improved apparatus applicable to a chimney or to a
vertical ventilating passage, a cowl is arranged so as to rotate by the action of
wind or external currents, but with the vane by means of which it turns placed so
as to keep the mouth or opening facing the current. The mouth is by preference
of a conical or flaring form, and the inner part of the cowl or funnel is made to
communicato with a pipe or passage acting as an inverted siphon, the air which 3
enters the cowl first passing vertically downwards a convenient distance, and then
proceeding through a curved or bent part of the pipe or passage so as to issue from
the terminal orifice in an upward direction, or in the direction in which the smoke,
or gas, or air passes along the flue or duct through which it is discharged. In this

page_text: way a jet of air, the force of which corresponds to that of the external current is
made to act on the smoke, or gas, or air in the direction for expelling it. The
air-inducing cowl may be fitted to the top of a chimney or chimney can, the siphon
pipe being placed entirely inside the Auc, and suitable outlet openings being
provided for the smoke.
In other modifications the air-inducing cowl and siphon pipe are placed outsirle
of the chimney or ventilating outlet and either near thereto or at any convenient
distance, and the jet end of the siphon pipe is inserted through the side into the
flue or passage.
A single air-inducing cowl may be arranged to supply jets to two or more flues
or passages, the siphon pipe, or its lower part, being provided with branch pipes, for
the several flues or passages.
In other modifications the air-inducing cowl is stationary and is formed with a
number of conical or flaring mouths or openings facing different ways so that in
whatever direction the external current may be it will have an opening facing it.
The several openings communicate with separate or distinct passages which extend
sufficiently down the siphon pipe to prevent the air entering at one opening from
passing out at another of the openings.
And in order that our said Invention and the manner of performing the same
may be properly understood we hereunto append a sheet of explanatory drawings
to be hereinafter referred to and representing various examples or modifications of
our improved apparatus. In these drawings the same reference numerals are used
to mark the same or like parts wherever they are repeated.
In the modification shown in figure, 1, on the accompanying sheet of drawings,
a conical mouth or funnel, 7, made of sheet metal and with a vane, 8, and curved
tube, 9, forms a movable piece or cowl which can turn about a vertical spindle, 10,
partly indicated by dotted lines. The position of the vane, 8, and the placing the
larger portion of the cowl to one side of the spindle, 10, cause the cowl to turn so
as always to have the mouth of its funnel, 7, facing the wind the direction of which
is indicated by the arrow, 11. The curved pipe, 9, of the cowl or movable piece
communicates with a pipe, 12, fixed inside the chimney, 13, and having its bottom
bended or curved so that its end, 14, is directed upwards, and the pipe, 12, 14, acts
as an inverted siphon. The air entering the funnel, 7, issues in an upward jet from
the siphon, 14, and acts on the smoke, or gas, passing up the chimney, 13, in a
manner to propel it outwards, and promote the draught.
-
In the inodification shown in figure, 2, the cowl or movable piece is placed
outside of the chimney, 13, the fixed siphon pipe, 12, 14, being made to pass
through the side of the chimney. A variation in the shape of the cowl is also
shown in figure, 2, the parts 7, 9, being in the form of a continuous curved
funnel.
A third modification of cowl is shown in figuros, 3, and 4, which are vertical and
horizontal sections. The entrance, 15, for the air is formed in one side of a
cylindrical shell, 16, made with a conical top, 17, and with a lower cone or
funnel, 18, leading down to the fixed siphon pipe, 12. A curved or inclined
plate, 19, is fixed inside of the cylinder, 16, in a position to deflect downwards the
air which enters horizontally. In figure, 3, the cowl is shown combined with a
cap, 20, fixed above the chimney top, 13, to prevent down blows, and consisting of
a flat under plate combined with a slightly coned upper plate. This cap, 20, may
be combined with any of the forms of cowl. The top of the fixed pipe, 12, and
the bottom of the cowl pipe or cone, 18, are shown as formed with annular
grooves, 21, of semicircular section, and an antifriction bearing is formed by
placing marbles or other small balls between these grooves to support the cowl.
Figures, 5, and 6, are vertical and horizontal sections of a modification of our
improved air-inducing cowl as made without movable parts, the cowl being fixed
to the top of the fixed siphon pipe, 12, 14. The cowl is made with a cylindrical
shell, 22, having a conical lower part, 23; and inside of this shell there is placed
a piece, 24, with curved sides which combines with the shell, 22, to form a number

page_text: of passages, 25. The piece, 24, is made with a top part, 26, projecting above the
cylindrical shell, 22, and formed with a number of flaring mouths, 27, for the tops
of the passages, 25. With this construction, in whatever direction the wind may
be blowing, it will have one or two of the mouths or openings, 27, facing it or
nearly so, and the air entering will pass down the passage or passages, 25, to the
siphon pipe, 12, 14.
Having thus particularly described our said Invention and the manner of
performing the same we have to state that we do not restrict ourselves to the
precise details herein described or delineated but that what we believe to be novel
and original and claim as the Invention secured to us by and in terms of the
herein before in part recited Letters Patent is :-
1. The combination of an air-inducing cowl capable of turning so that its
entrance always faces the wind or external air current, with a siphon pipe having
its issue orifice in a chimney or passage and directed upwards or in the direction of
discharge of the smoke, or gas, or air, substantially as hereinbefore described.
2. The combination of an air-inducing cowl without moving parts but with a
number of entrance openings facing different ways, with a siphon pipe having its
issue orifice in a chimney or passage and directed upwards or in the direction of
discharge of the smoke, or gas, or air, substantially as herein before described.
In Witness whercof J, the said Robert Girdwood, on behalf of the said
George Davis, William Jones, and myself have hereunto set my hand and
seal this ninth day of July in the year of our Lord One thousand eight
hundred and eighty-three.
Witness,
EDMUND HUNT,
Patent Agent
Glasgow
ROBERT GIRDWOOD (L.S.)