Improvements in or connected with Chimney or Ventilating Shaft Tops.
Year: 1893

page_text: Date of Application, 13th Mar., . 1893
Complete Specification Left, 7th Dec., 1893-Accepted, 27th Jan., 1894
PROVISIONAL SPECIFICATION.
Improvements in or connected with Chimney or Ventilating
Shaft Tops.
I, HENRY NEWMAN GODWARD 53 Victoria Street Westminster S.W.
Secretary do hereby declare the nature of this invention to be as follows:-
This invention relates to an arrangement for preventing down draughts in
chimney or ventilating shaft tops and for increasing the up current, and the same is
carried out in the following manner :-
I provide a suitable metal or other cone closed at the narrow bottom end; this
cone is inserted in the top of the chimney or chimney cowl and receives a second
cone open at its narrow bottom end and enlarged at its top end so as to form a
deflecting surface. Air striking the top of the chimney or chimney cowl passes
down the closed cone and is therefrom deflected upwards and passes out to the
external atmosphere between the closed and open cones thus forming an auxiliary
draught for smoke issuing from the chimney or cowl.
Dated this 13th day of March 1893.
E. EATON,
Patent Agent.
COMPLETE SPECIFICATION.
Improvements in or connected with Chimney or Ventilating
Shaft Tops.
I HENRY NEWMAN GODWARD of 53 Victoria Street, Westminster S.W.
Secretary, 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:-
This invention relates to an improved construction and arrangement of chimney
or ventilating shaft tops, whereby down-draught is prevented and an up current is
induced in the shaft or flue to which the said invention is applied.
According to my invention, I dispose an air deflecting chamber within and
slightly below the top of the chimney or ventilator shaft, said chamber being open
at the top and closed at the bottom and being also of smaller diameter than the
interior of the surrounding portion of the shaft so as to leave a free space between
it and the latter for the exit of smoke or fumes. Above this deflecting chamber
is suitably supported a funnel shaped air collector consisting of an inverted cone
(or it may be a dished plate or trumpet shaped mouth) from which a pipe leads
downwards into and terminates within the said deflecting chamber. Air striking
the chimney or ventilating shaft top passes down the said pipe of the air collector
into the deflecting chamber from whence it is deflected upwards and caused to pass
out of the shaft again between the top thereof and the air collector thereby
preventing down-draught and inducing an up current in the shaft.
I will now fully describe the manner of carrying out my invention referring
to the accompanying drawings in which similar letters refer to corresponding parts
in all the figures.
Fig. 1 is an elevation of a chimney or ventilating shaft top constructed according
to my invention.

page_text: Fig. 3 is a detached view of a deflecting chamber of slightly different shape to
that shewn in Figure 1.
Fig. 4 is a detached view shewing a supporting rod c and its guide d herein-
after referred to.
a is the tubular body of the device which is suitably secured to and forms the
continuation or top of the chimney or ventilating shaft. is the air collector sup-
ported above the chimney by the rods cc which slide freely in guides d provided
inside the tubular body a. Figure 4 shews clearly one of these rods and guides.
is a pipe leading down from the air collector b into the deflecting chamber e which
latter is suspended within the tubular body a at a little distance below the edge or
lip thereof by the stays f which connect it with the pipe 6' (or the deflecting
chamber e might be connected by stays with the rods c in lieu of to the pipe ¹).
It will be seen that plenty of space is left between the sides of the deflecting
chamber and the surrounding sides of the shaft top a, and also between the
edges of the top a and the underside of the air collector b, to permit of the free
exit of smoke and fumes. Down-draught through the last mentioned space is
prevented by the annular louvres or baffle plates g g secured by the stays to the
rods c.
Air striking the chimney top passes down the tube 6 of the air collector
into the deflecting chamber e which deflects it upward and causes it to pass out
again from the shaft as indicated by the arrows. Down-draught is thus prevented
and an up current induced in the shaft. When applied to a chimney my inven-
tion offers no obstacle to the sweeping of the same as a sweeps brush can be passed
right out of the top thereof lifting the device in its passage as indicated by the
dotted lines Figure 2. ii (Figure 2) are stops on the ends of rods c c to prevent the
device from being lifted too far and thus becoming accidentally disconnected from
the chimney top a.
When my invention is applied to a ventilating shaft the sliding rods c and
guides d may be dispensed with and fixed rods or other suitable supports substituted
therefor.
k is a drainage tube at the bottom of the deflecting chamber e which discharges
into a cup provided on the side of the top a and communicating by an aperture m
with the exterior thereof.
Fig. 3 shews the shape of deflecting chamber (with inverted conical bottom)
as originally designed and referred to in my Provisional Specification.
I am
inclined to think however that in sweeping the chimney the brush would be liable
to slip off the apex of this coned bottom and to jam between the same and the
sides of the shaft instead of lifting the device as intended, I therefore prefer to
employ the slightly modified form of deflecting chamber shewn in Figure 2
which receives the head of the brush and obviates any chance of the same
slipping.
In conclusion I would observe that I am aware that deflecting plates or chambers
disposed outside and above the top of a chimney or ventilating shaft and combined
or not with an air collector have before been proposed and therefore I lay no
claim to any such arrangement as forming part of my present invention.
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 :-
1. Means for preventing down-draught and creating an up current in chimney
and ventilating shafts, consisting of a deflecting chamber open at the top and
closed at the bottom situated within and below the level of the top of the shaft, an
air collector disposed above the shaft, and a pipe leading from such air collector
to and terminating within the deflecting chamber, substantially as described and
illustrated.
2. For preventing down-draught and inducing an up current in chimney and
ventilating shafts, a deflecting chamber suspended within the shaft top, an air
collector supported above the shaft top, and a pipe leading from the air collector

page_text: into the deflecting chamber, combined with means for permitting the deflecting
chamber to be raised clear of the shaft by a sweeps brush substantially as described
and illustrated.
3. The general construction arrangement and combination of parts constituting
a chimney and ventilating shaft top substantially as described and illustrated.
Dated this 7th day of December 1893.
E. P. ALEXANDER & SON,
Fels. Chartered Inst. Patent Agents,
19, Southampton Buildings, Chancery Lane, London, W.C.,
For the Applicant.