Year: 1895

page_text: "I, ALFRED CONWAY, of 42,' Durham Row, High Street, Stepney, London, E.
Stove and Range 'Maker, do hereby declare the nature of this invention to be.as
follows:-
The object of my invention is to provide a chimney pot which, shall effectually
prevent down-draught. The chimney pot is closed at its upper end, and is provided
with a series of lateral openings, (whose aggregate area should be, at least double
that of the flue) equally, disposed, about, its, sides, each, of such openings, having a
flap-valve closing, inwardly and hung upon a horizontal, hinge, at its upper, edge.
Normally the flap-valve is held slightly open by being so balanced that its lower
10 send. tends to swing clear of the side of the chimney pot, the counterweight required
for effecting, this being arranged externally so as not to interfere with the, free
passage in the interior of the chimney.
"
I
Upon a gust of wind striking the chimney, the external, air, pressure causes the
flap valve or valves upon the side exposed, to the wind to close. The external air
15pressure is thus prevented from, penetrating to the interior of the chimney, and,
Accordingly, no down-draught.is produced. The remaining flap-valves.. being
-qunaffected, their openings remain, available for the, escape of the up-draught, and
products of combustion. Upon the external air pressure, due, to, the wind,
ceasing the flap-valves which were exposed thereto, return, to, their,normal.open
20aposition..
L
..
In order to prevent external currents of air from penetrating sideways behind
the vertical edges of the flap-valves, when the latter are open, each lateral opening
in the chimney.pot is provided with two outwardly projecting plates, one such plate
extending the whole length of each of its vertical edges, and placed, just, so, far
25,apart as to allow the flap-valve to swing freely between them.
"
The upper end of the chimney.pot is closed by means of a loosely fitting cap so
arranged as to be capable of being raised some distance clear of the top of the pot
by, the sweep's brush when the latter is thrust up from beneath. This is effected
by the cap having attached to it a number, (preferably three, or more) of,rods which
30 extend downwards around the outside of the chimney, pot a sufficient distance. to
permit of the required lift of the cap and passing, through guide brackets.against
which stops, provided on the lower ends, of, the rods, for arresting the upward
movement of the cap, are adapted to strike.
$

page_text: i
!
1
I, ALFRED CONWAY, of 42, Durham Road, High Street, Stepney, London, E..
Stove and Range Maker, 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 my invention is to provide a chimney pot which shall effectually
prevent down-draught.
The invention is illustrated in the accompanying drawings, forming part of this
Specification, wherein Figures 1 and 2 are respectively sectional and side elevations,
Figure 3 being a sectional plan on line 3-3, Figure 2.1
The same letters of reference denote like parts in all the figures.
The chimney pot A. is closed at its upper end by means of the cap B and is
provided with a series of lateral openings C, C, (whose aggregate area should be
at least double that of the flue) equally disposed about its sides, each of such
openings having a flap-valve D closing inwardly and hung upon a horizontal
hinged at its upper edge. Normally the flap-valve D is held slightly open by
being so balanced that its lower end d¹ tends to swing clear of the side of the
chimney pot, the counterweight required for effecting this being arranged either
externally, as at E, or internally, as at F, being, however, in the latter case,
arranged so as (when hanging in its normal position) not to seriously interfere with
the free passage in the interior of the chimney..
Upon a gust of wind striking the chimney, the external air pressure causes the
flap valve or valves D, D, upon the side exposed to the wind, to close. The
external air pressure is thus prevented from penetrating to the interior of the
chimney, and, accordingly, no down-draught is produced. The remaining flap-
valves being unaffected, their openings remain available for the escape of the
up-draught and products of combustion. Upon the external air pressure, due to
the wind, ceasing, the flap-valves which were exposed thereto return to their normal
open position.
In order to prevent external currents of air from penetrating sideways behind
the edges of the flap-valves when the latter are open, each lateral opening in the
chimney pot is provided with two outwardly projecting guard plates G, one such
plate extending the whole length of each of its vertical edges, the plates being
placed just so far apart as to allow the flap-valve D to swing freely between
them.
The upper end of the chimney pot is closed by means of a loosely fitting cap B
so arranged as to be capable of being raised some distance clear of the top of the
pot by the sweep's brush when the latter is thrust up from beneath. This is
effected by the cap B having attached to it a number (preferably three or more) of
guide rods which extend downwards around the outside of the chimney pot a
sufficient distance to permit of the required lift of the cap and passing through
guide brackets a attached to the pot and against which stops b', provided on the
lower ends of the rods, for arresting the upward movement of the cap, are adapted
to strike. The cap B is preferably made of conical shape, so as the more readily
to throw off the raiu..
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
A chimney not constructed with lateral openings provided with halanced Aan-

page_text: valves and guard plates the pot having a cap adapted to slide vertically in
guides when raised by the sweeping brush, substantially as and for the purpose
specified.
Dated this 22nd day of October 1895.
A. M. & WM. CLARK,
53, Chancery Lane, London, Chartered Patent Agents.