IMPROVEMENTS IN APPARATUS FOR EXTRACTING FOUL AIR OR SMOKE FROM BUILDINGS, SEWERS, OR CHIMNEYS
Year: 1878

page_text: LETTERS PATENT to Edward Thomas, of 4, City Gardens, City Road, London,
<<
in the County of Middlesex, for the Invention of IMPROVEMENTS IN
APPARATUS FOR EXTRACTING FOUL AIR OR SMOKE FROM BUILDINGS, SEWERS,
OR CHIMNEYS."
Sealed the 9th July 1878, and dated the 25th February 1878.
PROVISIONAL SPECIFICATION left by the said Edward Thomas at the Office
of the Commissioners of Patents on the 25th February 1878.
EDWARD THOMAS, of 4, City Gardens, City Road, London, in the County of
Middlesex. "IMPROVEMENTS IN APPARATUS FOR EXTRACTING FOUL AIR OR SMOKE
FROM BUILDINGS, SEWERS, OR CHIMNEYS."
This Invention relates to the purposes of ventilation, and is intended to be used
in places where a powerful up current may be required for the exhaustion of foul
air from public buildings, dwelling houses, sewers, &c.
The foul air is exhausted by means of a screw of peculiar form, which is kept
revolving by the action of the wind or by any convenient mechanical appliance.
This apparatus is composed of a series of spiral formations affixed to a central
tube in such a manner as to form a double screw, the inner being overlapped
by the outer when the article is to be used as a ventilator, but when used as a
smoke extractor on chimneys, for which the Invention is also expressly and well
adapted, the inner portion is left out and the screw revolves on a pivot from the
top instead of round a central tube.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Edward Thomas in the Great Seal Patent Office on the 21st August
.1878.
"
EDWARD THOMAS, of Number 4, City Gardens, City Road, in the County of
Middlesex, Zinc Worker. IMPROVEMENTS IN APPARATUS FOR EXTRACTING FOUL
AIR OR SMOKE FROM BUILDINGS, SEWERS, OR CHIMNEYS."
This Invention has for its object improvements in apparatus for extracting foul
air or smoke from buildings, sewers, or chimneys.
The apparatus consists principally of a vertical shaft surmounted by an improved
form of revolving screw so constructed as to produce, when acted upon externally
by the wind or by other force applied, a powerful up current from the shaft; this
result is obtained by means of a series of blades made of any suitable material, by
preference of metal, fixed to each other so as to form what may be termed a double
screw having a series of separate air ducts or channels, up which foul air or smoke
is drawn. When the screw revolves, the outer portion overlapping with the inner
prevents the entrance of rain to the interior.
In applying this Invention for the purpose of creating an up-draught in chimneys,
I purpose to use only the outer portion of the screw, leaving the interior free from
obstruction, so that the sweep's brush may pass.
Having thus described the nature of my said Invention, I will now proceed by
the aid of the accompanying Drawings to describe more particularly the method
of constructing the apparatus and of carrying my said Invention into effect.
Figure II. is a ground plan of the screw C, C, C, C, in Figures I. and VL
Figure III. is a plan of the stays K in Figures I. and VI., supporting the oil
tube G in Figure I., and the oil box R in Figure VI.
Figure IV. is a vertical section of the apparatus when used as a smoke or dust
extractor.
Figure V. is a ground plan of the screw C in Figure IV.
Figure VI. is a vertical section of a modification of the apparatus shewn in
Figure I., that is, when the apparatus is used as a ventilator, which modification
consists in supporting the top cone by iron straps T, T, and a different arrangement
of the spindle and oil vessels.
Figure VII. is a vertical section of a similar modification to Figure VI. of the
apparatus shewn at Figure IV., that is to say, when the apparatus is to be used as
a smoke or dust extractor.
A is an air shaft in case of a ventilator or a chimney in case of a smoke
extractor.
B, B, is the outer rim forming the mouth of the air shaft or chimney, into
which the lower portion of the screw C, C, C, C, revolves.
E, E, are outlets, which provide an escape for any moisture that may collect upon
the outer portion of the screw, which is prevented from running down the air
tube A by the conical rim D, D.
C, C, C, C, in Figures I. and VI. is the screw, the portions of which marked
respectively 1, 2, 3, 4, correspond to the portions marked with the same figures in
Figure II.
C, C, C, C, in Figures IV. and VII, is the screw, the portions of which marked
respectively 2, 3, 4, correspond to the portions marked with the same figures in
Figure V.
P, P, is an inner conical tube, to which are fixed the blades of the screw C, C, C, C,
when the apparatus is used as a ventilator, but when used as a smoke extractor the

page_text: blades of the screw are bound together by a ring at the top and a ring at the
bottom Y, Y, which take the place of the said conical tube.
G is an oil box in which the spindle H revolves.
N is a feed pipe, through which oil is conveyed to the oil vessel.
M, M, is an outline of the fans, by means of which the wind causes the apparatus
to revolve. These fans vary in number according to the size of the ventilator or
smoke extractor. In a ventilator with a five inch pipe I have found twelve a
convenient number.
F, F, are outlets for the air conveyed up the inner portions of the screw when
the apparatus is used as a ventilator; these outlets are not required when the
apparatus is used as a smoke extractor.
O, O, are iron straps supporting the oil box G when the apparatus is used as a
smoke extractor.
T, T, are iron stays supporting the top cone W and the vertical tube X in the
modifications shewn in Figures VI, and VII.
R, R, are separate oil cups connected by the tube S in the same modifications.
Having thus fully described and ascertained the nature of my said Invention,
and the manner in which the same may be performed and carried into effect, I
desire it to be understood that I do not claim the use of a revolving vane or screw
revolving within a tube, as I am aware that such an apparatus has been used, and
that Provisional Protection was granted to James Howarth for the same on his
application for Letters Patent, dated 19th April 1858, No. 853/58, nor do I claim
the use of an external screw when fixed or immovable, as such arrangement has
been the subject of a registered Design, No. 5969, registered by Messieurs Ewart
and Son, of 346, Euston Road, London, on the 7th November 1877, but what I
do claim as the Invention secured to me by the herein-before in part recited Letters
Patent is, the apparatus herein-before described and shewn in the Drawings here-
unto annexed for extracting foul air or smoke from buildings, sewers, or chimneys,
in which said apparatus a revolving external screw is used in the manner herein
described and shewn for the purpose of extracting the foul air, smoke, or dust from
the said air shaft or chimney.
In witness whereof, I, the said Edward Thomas, have hereunto set my hand
and seal, this Twenty-first day of August, in the year of our Lord One
thousand eight hundred and seventy-eight.
EDWARD THOMAS. (L.S.)