IMPROVEMENTS IN REVOLVING VENTILATORS
Year: 1879

page_text: LETTERS PATENT to John Rothwell, of Farnworth, in the County of Lancaster,
for the Invention of "IMPROVEMENTS IN REVOLVING VENTILATORS."
Sealed the 19th August 1879, and dated the 10th June 1879.
PROVISIONAL SPECIFICATION left by the said John Rothwell at the Office
of the Commissioners of Patents on the 10th June 1879.
E
JOHN ROTHWELL, of Farnworth, in the County of Lancaster. IMPROVEMENTS
IN REVOLVING VENTILATORS."
My Invention relates to the ventilators which are arranged to revolve upon
vertical axes and are provided with screws which revolve within the air conduits,
and by their exhausting action induce the flow of currents of air through the
ventilators. In such ventilators as constructed previously to my Invention the air
has been delivered through slits or side openings between curved plates which have
been fixed around the circumference of the revolving body. In lieu of this arrange-
ment I deliver the air upwards through the open top of the said revolving body,
and I close the circumference of the said body and provide it with curved plates or
vanes upon which the wind acts to impart the revolving motion to the said body.
Above the said revolving body I mount a cowl or cap which is revolvable and is
provided with a vane, that is to say, with a part upon which the wind may act to
turn the said cap or cowl, as will be well understood. The said cap or cowl is
formed with one or more side openings or with a delivery mouth or with mouths
through which the issuing air is delivered in or about in the direction of travel of
the wind. As the passage for the issuing air is large and free it is not so liable to
become choked as in the case of the narrow passages in the ordinary ventilators,
and as the delivery mouth is turned away from the wind down draughts are avoided
and the wind aids rather than checks the flow of air from the ventilator. In some
or in all cases I may form side air conduits through which air may flow downwards
and be delivered into the space to be ventilated. To render the ventilator more
useful and ornamental I in some cases provide it with means for indicating the
points of the compass, the aforesaid cap or cowl answering the purpose of an ordinary
weather vane.

page_text: =
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said John Rothwell in the Great Seal Patent Office on the 10th
December 1879.
JOHN ROTHWELL, of Farnworth, in the County of Lancaster.
IN REVOLVING VENTILATORS."
"IMPROVEMENTS
My Invention relates to the ventilators which are arranged to revolve upon
vertical axes and are provided with screws which revolve within the air conduits,
and by their exhausting action induce the flow of currents of air through the
ventilators.
In such ventilators as constructed previously to my Invention the air has been
delivered through slits or side openings between curved plates which have been
fixed around the circumference of the revolving body. In lieu of this arrangement
I deliver the air wholly or partly upwards through the open top of the said
revolving body, and in some cases I close the circumference of the said body and
provide it with plates or wings upon which the wind acts to impart the revolving
motion to the said body. Above the said revolving body I mount a cowl or cap
which is removable and is provided with a vane, that is to say, with a part upon
which the wind may act to turn the said cap or cowl, as will be well understood.
The said cap or cowl is formed with one or more side openings or with a delivery
mouth or with mouths through which the issuing air is delivered in or about in
the direction of travel of the wind. To render the ventilator inore useful and
ornamental I, in some cases, provide it with means for indicating the points of the
compass, the aforesaid cap or cowl answering the purpose of an ordinary weather
vane.
In order that my Invention may be fully understood I will now refer to the
(Sheet of Drawings which I have attached hereunto. In the said Drawings Fig. 1
represents an elevation of a complete ventilator constructed in accordance with my
Invention; Fig. 2 represents a vertical section on a plane at right angles to
Fig. 1; and Fig. 3 is a cross section on the line A. In the said Figs. a is a
hollow casing which sustains the parts of the apparatus and also serves as a
conduit through which the air flows in an upward direction to the delivery mouth.
'A ring b is attached by means of bars c to the said casing. A footstep bearing d
is carried by a cross-bar which extends across the passage through the casing a and
an upper bearing e is carried by a cross bar which is attached to the ring b. A
spindle fis fitted to revolve in the said bearings, and on this spindle are fixed the
revolving body g and the screw or fan h. The said revolving body in the example
is made in the form of a hollow cylinder open at both ends and formed without side
openings, and the said body is furnished with curved plates or wings which are so
fixed to the body as to be tangents to a circle a little within the body as indicated
by Fig. 4, which is a cross section on the line B. When the ventilator is in action
the wind impinging on the said wings imparts a revolving motion to the body g
and thereby to the spindle f, and the screw h is thereby caused to revolve within
the casing a. The aforesaid cross bar which is fixed to the ring b carries a vertical
spindle upon which a cowl k is mounted. This cowl is furnished with a vane l
and is formed with a side opening which fronts the spectator in Fig. 2, this opening
being shielded by means of a hood . The said cowl is so mounted upon the spindle
so as to be capable of yielding readily to the action of the wind upon the vane Z
as is usual in the cases of ordinary cowls. The spindle f is also suitably mounted
to revolve with little friction so that the action of the wind upon the wings on the
body g causes a rapid revolution of the screw h, whereby an upward current of air
is induced. This upward current passes through the body ginto the cowl and flows
out through the opening in the side of the said cowl. The wind also acting on the
vane keeps the said cowl in such a position with regard to the direction of travel
of the wind as that the said opening is always turned away from the wind, and the
air is thus delivered in the same direction as the wind as aforesaid, whereby the

page_text: practical efficiency of the ventilator is increased. As the passage for the flow of air is
large and comparatively free it is not so liable to become choked with dust or with fluff
or fibrous matters as in the case of the narrow passages in the ordinary ventilators,
and by reason of the delivery mouth in the cowl being turned away from the wind
down draughts are avoided and the entry of rain is nearly or entirely prevented.
In the example arms m are attached to the ring b, and the usual signs to mark the
four cardinal points of the compass are fixed to the said arms. These signs render
the ventilator more useful and ornamental for some purposes, but I do not apply
them in all cases. The ventilator may otherwise be rendered ornamental to suit
varying requirements, and a curved cowl of the form applied to blowing rooms or a
revolvable cowl of any suitable form may be substituted for the cowl k. Figs. 5
and 6 illustrate a modification in the revolving body g. In this example the wings
on the said body are inclined with respect to the axis of revolution and are curved
and extended inwards as indicated in Fig. 6, and there are openings for the free
passage of air between the said wings, so that the air can escape between the said
wings as well as through the cowl. The formation of the said wings causes the
revolving body to have a screwing action upon the air, whereby the upward draught
is increased. Fig. 7 illustrates another modification wherein a fixed cowl or bonnet
is substituted for the revolving cowl. In this case the air flows upwards into the
said bonnet and leaves it through an annular space between the lower edge of the
bonnet and the ring b. Although I have only mentioned air as passing through
the said ventilators, it must be understood that they are adapted for application to
chimneys and for all the ordinary uses of such appliances. In some cases I may
arrange for the screw to be driven by power.
Having now fully set forth and indicated the nature of my said Invention and
the manner in which I carry the same into practical effect, I would have it to be'
understood that I claim,-
First. The combination of parts arranged and acting substantially as and for
the purpose set forth and indicated hereinbefore and in and by the accompanying
Drawings.
Secondly. The revolving body combined with the revolvable cowl, substantially
as set forth and indicated.
And, Lastly. The indications of the cardinal points combined with the revolvable
cowl and vane, substantially as set forth and indicated.
In witness whereof, I, the said John Rothwell, have hereunto set my hand
and seal, this Ninth day of December, in the year of our Lord 1879.
JOHN ROTH WELL.
LS
Signed and sealed by the said
John Rothwell, in the pre-
sence of
EDWARD K. DUTTON,
Agent to the Patentee,
St. Ann's Churchyard,
Manchester.
JOHN ROTHWELL