Improvements in or relating to Chimney Tops or Cowls.
Year: 1897

page_text: Date of Application, 30th July, 1897-Accepted, 2nd Oct., 1897
COMPLETE SPECIFICATION.
Improvements in or relating to Chimney Tops or Cowls.
I, FRITZ WISKEMANN of Cassel in the Empire of Germany, Manufacturer 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 a chimney top or cowl characterised by a rotatable
cap with an air-shaft which is always turned towards the direction of the wind
by a vane, and directs the wind downwards, into a fixed or movable bell- or
funnel-shaped vessel in the interior of the chimney, below the lower narrow mouth
of said air-shaft for the purpose of reversing the downward air-current, and
converting it on the opposite side to the air-inlet into an upward air-current
which thus exercises a sucking action on the smoke- or combustion-gases rising
in the chimney. The air-shaft is gradually tapered inwards towards its lower
outlet, in order to produce a certain amount of compression of the air drawn in.
The air-shaft is separated from the air-outlet.
The invention is illustrated in the accompanying drawings in which
Figure 1 is a longitudinal section of the chimney-top.
Figure 2 an elevation from the side on which the air-inlet is arranged.
Figure 3 is a cross-section of Figure 1 and
Figure 4 a plan.
In the chimney a is secured slightly below the top a bell- or funnel-shaped
vessel b by means of stays c. A bearing at the bottom of said vessel b carries
the spindle f of the rotatable top. The latter is constituted by a funnel or part
funnel h sharply tapered downwards and an air-shaft at one side of it, constituted
by front-walls k base and funnel wall h said shaft tapering down towards its
outlet into the bell b.
In order to prevent wind from blowing into the chimney top or bell at any
other place than through the air-shaft and thus forming eddy or counter-currents,
there is provided on the rotatable funnel a casing or jacket m, round the air-shaft,
which extends round,, say a third of the circumference of the top and prevents
air from entering the bell b except through the air-shaft.
The air-shaft turned by the vane y towards the direction of the wind catches
part of it and compresses it, in its narrowed lower part and causes it to enter
the bell in a downwardly inclined direction. The bell reverses this air-current
so that the air escapes from the bell on the opposite side to that of the air-shaft
in an upward direction and exercises a sucking action on the smoke and
combustion gases in the chimney.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is;
1. A chimney top or cowl comprising a funnel h tapered downwards and provided
with an air-shaft constituted by lateral walls k, funnel wall h and base 1, and a
jacket m. the cowl being adanted to be turned towards the direction of the mind

page_text: by a vane g, in combination with a bell or funnel shaped vessel in the interior
of the chimney, said vessel reversing the compressed air-current introduced
through the air-shaft directing it upwards, and drawing out the smoke or com-
bustion gases from the chimney and enabling them to escape on the side opposite
to that of the air-shaft, substantially as described.
2. The combination and arrangement of parts constituting the complete
chimney top or cowl, substantially as described and illustrated in the accom-
panying drawings.