IMPROVEMENTS IN COWLS AND SHAFTS
Year: 1877

page_text: LETTERS PATENT to Charles Richard Stevens, of Lee, in the County of
Kent, for the Invention of "IMPROVEMENTS IN COWLS AND SHAFTS."
Sled the 19th Mauch 1978 and dated the 13th December 1877.
PROVISIONAL SPECIFICATION left by the said Charles Richard Stevens
at the Office of the Commissioners of Patents on the 13th December 1877.
CHARLES RICHARD STEVENS, of Lee, in the County of Kent. "IMPROVEMENTS
IN COWLS AND SHAFTS."
The improvements consist as regards cowls in furnishing the shaft thereof with a
cap supported on it, but with a passage-way left round the shaft protected by a
flanged or flared collar supported by partitions suspended from the cap of the shaft,
which is covered.
The action is as follows:-The air, gas, or smoke passing upwards through the
passage-way is deflected downwards by the cap cover and through the flared collar,
and the atmosphere impinging on the partitions assists in driving downwards
and outwards said air, gas, or smoke, and thus creates an up-draught in the
shaft.
The improvements in shafts consist in making them with a diaphgram or division
running through, and thus in double sections, and carrying one of such sections
through the top of the improved cowl, with an orifice to said section, the other
section finishing with an open orifice under the cap.
Also in making the cap with an under receptacle carrying partitions supporting
the cover in such manner that the atmosphere impinging against the partitions is
driven down one section of the shaft, thereby causing an up-draught up one section
and a down-draught down the other.
The improvements may be made of metal or earthenware, and in various shapes
in cross section.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Charles Richard Stevens in the Great Seal Patent Office on the
13th June 1878.
CHARLES RICHARD STEVENS, of Lee, in the County of Kent. "IMPROVEMENTS
IN COWLS AND SHAFTS."
The improvements consist as regard cowls in furnishing the shaft theroof with a
cap supported on it, but with a passage-way or ways left round the shaft protected
by a flanged or flared collar supported by partitions suspended from the cap of the
shaft which is covered.
5
The action is as follows:-The air, gas, or smoke passing upwards through the 1
passage-ways is deflected downwards by the cap cover and through the flared collar,
and the atmosphere impinging on the partitions assists in driving downwards
and outwards said air, gas, or smoke, and thus creates an up-draught in the
shaft.
The improvements in shafts consists in making them of one piece, with a diaphragm 1
or division running through, and thus in double sections, and carrying one of such
sections through the top of the improved cowl, with an orifice to said section, the
other section finishing with an open orifice under the cap.
Also in making the cap with an under receptacle carrying partitions supporting
the cover in such manner that the atmosphere impinging against the partitions is 2
driven down one section of the shaft, thereby causing an up-draught up one section
and a down-draught down the other.
Also in combination with the said shafts and cowls or otherwise, of a drawer
ventilator that can be opened and drawn out to the extent desired.
Also in the arrangement of a cover piece or cap to existing ventilating cowls, as 2
explained hereafter.
The accompanying Drawings will serve to illustrate practical modes of performing
the improvements, but in matters of detail, form, and ornamentation they can be
cousidorably varied without departing from the nature of the improvements.
Fig 1 shows elevation, and Fig. 1a a section of a double ventilator cap fitted to 3
a double shaft c, half of said shaft being carried through the cap, as at d. The
top of the shaft is furnished with partitions a, a, and the air impinging on
them is deflected down one section of shaft; the under part of cowl has a
conical rim or collar e at bottom; the air being deflected down through this
rim or collar by the partitions 6 causes a partial vacuum under the cap and 3
creates an up-draught in the other section of the shaft.
Figs. 2 and 2 are respectively elevation and section of a modification of cowl, the
shaft being supplied with a cap g, and a conical deflecting rim or collar h. In
this case the partitions i deflect the air through the rim h, thereby causing a partial
vacuum under g, and so creating an up-draught in shaft f
Figs. 3, 4, and 5 shows other modifications; the two former in section, the latter
a sectional plan.
In all the Figures the direction of the currents of air is shown by the arrows.
Figs. 6 and 7 are sections of a cylindrical shaft showing the mode of forming and
closing same.
b
Fig. 8 shows section of the improved cover a, supported by stays 6 or otherwise,
BO as to cover the aperture of the ventilating cowl shaft c, and by means of
such cover the down-draught is avoided, and the up-draught is increased in the
shaft c.
4
4
Fig. 9 is section of the drawer apparatus to be used in combination with down- 5
draught shaft X or otherwise; it is supplied with divisions, so that by drawing out
one or more of such divisions the admission and passage of air is regulated.
Fig, 10 is section of a chimney or ventilating cap, with partitions arranged to
create an up-draught.

page_text: Figs. 11 and 12 are respectively elevation and sectional elevation of a cluster
arrangement of several up-draught shafts m and one down-draught shaft n. In
this case 6 up-draught shafts are shown, and one large down-draught, also one
deflecting collar o, but it is obvious that the shafts may be varied in number
and proportions, as also the deflecting collar.
Fig. 13 is a section through A, B, Fig. 12.
In witness whereof, I, the said Charles Richard Stevens, have hereunto
set my hand and seal, this Twelfth day of June, in the year of our Lord
1878.
CHARLES RICHARD STEVENS. (L.S.)