Year: 1888

page_text: I JAMES HOWORTH of Victoria Works, Farnworth in the County of Lancaster,
ventilating engineer, 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 :-
--
My invention relates to the kind of selfacting ventilators fixed upon the top of flues
or roofs of buildings and consisting of a revolving hood or cowl fitted with wind vanes
actuated by the wind to which a propeller in a cylindrical casing is connected and by its
rotation draws the air from the flue or building and ejects it through vertical openings
formed by side vanes connected to the revolving hood. My improvements consist in
an improved form or shape of the said wind and side vanes and the application of an
improved kind of propeller to selfacting ventilators of the kind referred to, the object
of said improvements being to increase the efficiency of the ventilator and to produce a
more powerful exhaust.
On the sheet of drawings appended hereunto fig. 1 shows a side view of my
improved ventilator, fig. 2 a sectional plan of the same, the section being taken along
line XY of figure 1; fig. 3 shows a top view; fig. 4 shows the improved form of
wind vane flattened out or before being bent and attached to the revolving hood,
and fig. 5 the form of wind vanes previously used.
The top
The ventilator consists similar to those at present in use of a cylindrical casing a
which is fixed upon the ventilating or chimney flue, and to which the top 6 is
connected by arms ccc.
contains the top bearing for a spindle d
supported below by a footstep carried by arms attached to the casing a. Upon the
spindle a revolving hood is mounted, consisting of the conical top or dome e and the
lantern f. To the dome e the wind vanes g are fixed by soldering or other suitable
means, while the lantern f is formed by the side vanes h soldered or otherwise
attached to the dome e at the top and a ring i at the bottom, which is connected to the
spindle d by arms & on a boss l. The spindle d carries inside the casing a a propeller
or fan and as the hood b is revolved by the wind, it rotates the spindle d and the
propeller and exhausts the air from below the propeller and expels it through the
lantern f

page_text: The wind vanes 9 have hitherto been made of the shape shewn by fig. 5 before being
bent to an arc, the vane having a crescent shape when attached to the dome e at the
side m of the vane. One of my improvements consists in making the vanes before
being bent of a shape similar to that shewn on fig. 4 and bending them at the part n o
to a right angle or approximately so with a slightly rounded corner and placing them
upon the dome with the bent part of the vane nearly parallel to the lower edge of the
dome. By this shape and position of the vanes a deeper cavity is formed under each
vane, thereby causing the wind to collect more readily under the vanes and in order
to escape drive the revolving hood round more rapidly than with the old form of vanes,
and thus a greater speed of rotation of the propeller and thereby a more powerful
exhaust is produced.
The vertical sido vanes h, which are arranged to let the air exhausted from the
rooms out from the ventilator have previously been made curved at their bottom ends,
necessitating a great width of the ring i for attaching their curved sides to the same.
My further improvement consists in bending the side vanes at the bottom g' at right
angles to the vertical surfaces, by which means the space for outlet is increased, as
the ends of the vanes only are attached to the ring i and the latter can be made
narrower. The air consequently escapes more freely and meets with less resistance,
whereby the efficiency of the ventilator is increased for the same length of vanes or
lantern.
My further improvement consists in using in combination with the revolving hood
propellers constructed in a similar manner as the propellers rotated by power for
which Letters Patent dated the 12th January 1888 and numbered 511 have been
granted to me, instead of the archimedean screw or radial vane propellers previously
used. As described in the specification for the said Patent I make the propeller out
of a circular sheet of metal slit into 3 or more sections by preference with curved
edges and bend the radial edges so that the leading edges are lower than the
following edges q. These propellers scoop up the air similarly to archimedean screw
propellers and at the same time impart to it centrifugal force like radial vane
propellers and propell it in an upward direction into the hood whence it escapes between
the vertical vanes h.
Having now particularly described and ascertained the nature of my said invention
and in what manner the same is to be performed, I declare that what I claim is,
Firstly. The shape and construction of the wind vanes of selfacting propeller ventilators
substantially as herein before described and shewn on the drawings.
Secondly. Making the side vanes of selfacting propeller ventilators bent to a right
angle or approximately so at their lower ends, substantially as hereinbefore described
and illustrated.
Thirdly. The combination of propellers constructed as specified in Specification
No. 511 of 1888 with hoods revolved by the wind.
Fourthly. The combination of the improvements specified in the three preceeding
claims in one apparatus.
Dated this 20th day of July 1888
EMMOTT & Co.,
Agents for the Applicant.