IMPROVEMENTS BAD DRAWING DRAHON IN CHIENDS
Year: 1857

page_text: LETTERS PATENT to William Sandilands, of Inveresk, in the County of
Mid Lothian, North Britain, Smith, for the Invention of "IMPROVEMENTS
BAD DRAWING DRAHON IN CHIENDS"
PROVISIONAL SPECIFICATION left by the said William Sandilands at
the Office of the Commissioners of Patents, with his Petition, on the
30th September 1857.
I, WILLIAM SANDILANDS, of Inveresk, in the County of Mid Lothian, North
Britain, Smith, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN: CHIMNEY CANS OR APPARATUS FOR PROMOTING DRAUGHT IN
CHIMNEYS," to be as follows, that is to say :-
This Invention relates to the arrangement and construction of chimney.
cans or fixed apparatus for attachment to the tops of chimneys for the purpose
of securing an efficient carrying off of the smoke and a good draught up the
chimneys independent of the action of the external atmosphere.. The main
shell of the chimney can consists of a cylindrical metal tube, the upper end of
which is encircled by a short length of wider tube; which; stands up to some
distance above the level of the upper end of the main central tube, and is.
bell-mouthed at its open top. This shorter piece of tube is attached to the
main tube by suitable open stay pieces, which leave a passage for air between..

page_text: the two sections. The actual end of the open main tube is sheltered or
covered by a conical cap open directly through it from end to end, and set
with its small end upwards. This conical cap is fitted with supporting stay
or leg pieces by which it is adjusted at some little distance above and free of
the upper end of the main tube. This can allows of a free draught passage
up through it whilst the form and arrangement of the parts prevent any of the
disturbing influences ordinarily. arising from blow downs.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Sandilands in the Great Seal Patent Office on the
30th March 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
SANDILANDS, of Inveresk, in the County of Mid Lothian, North Britain, Smith,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirtieth day of September, in the year of our Lord
One thousand eight hundred and fifty-seven, in the twenty-first year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said William Sandilands, Her special license that I, the said William
Sandilands, my executors, administrators, and assigns, or such others as I, the
said William Sandilands, my executors, administrators, or assigns, should at
any time agree with, and no others, from time to time and at all times there-
after during the term therein expressed, should and lawfully might make, use,
exercise, and vend, within the United Kingdom of Great Britain and Ireland,
the Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
CHIMNEY CANS OR APPARATUS FOR PROMOTING DRAUGHT IN CHIMNEYS," upon the
condition (amongst others) that I, the said William Sandilands, by an instru-
ment in writing under my hand and seal, should particularly describe and
ascertain the nature of the said Invention, and in what manner the same
was to be performed, and cause the same to be filed in the Great Seal,
Patent Office within six calendar months next and immediately after the date
of the said Letters Patent.
NOW KNOW YE, that I, the said William Sandilands, do hereby declare
the nature of my said Invention, and in what manner the same is to be per-,
formed, to be particularly described and ascertained in and by the following
statement in writing, reference being had to the accompanying Drawings,.
and to the letters and figures marked thereon, that is to say:-

page_text: My said Invention relates to the arrangement and construction of chimney
cans or fixed apparatus for attachment to the tops of chimnies for the purpose
of securing an efficient carrying off of the smoke and a good draught up the
chimnies independent of the action of the external atmosphere. The main
shell of the chimney can consists of a cylindrical metal tube, the upper end of
which is encircled by a short length of wider tube, which stands up to some
distance above the level of the upper end of the main central tube, and is
bell-mouthed at its open top. This shorter piece of tube is attached to the
main tube by suitable open stay pieces, which leave a passage for air between
the two sections. The actual end of the open main tube is sheltered or
covered by a conical cap open directly through it from end to end, and set
with its small end upwards. This conical cap is fitted with supporting stay
or leg pieces, by which it is adjusted at some little distance above and free of
the upper end of the main tube. This can allows of a free draught passage
up through it, whilst the form and arrangement of the parts prevent any of
the disturbing influences ordinarily arising from blow-downs.
And in order that my said Invention may be properly understood, I shall
now proceed to describe the several illustrative Figures on the explanatory
Sheet of Drawings which I have hereunto appended for the purpose of
showing certain modifications under which my improvements may be judi-
ciously carried out in practice.
Figure 1 on my Sheet of Drawings is an elevation or external view of one
modification of my improved chimney can or top; Figure 2 is a vertical
section, and Figure 3 a plan, of the same. The lower portion of the
chimney can consists of a cylindrical metal tube A, the bottom part of which
fits into the upper part of the chimney, and is secured thereto by the flanged
metal ring B. The upper extremity of the main tube A is surrounded by.
a tube C, which is of greater diameter than the tube A; the lower open end'
of the tube C is arranged so that its edge is a short distance below the upper
edge of the tube A. The tubular parts A and C are connected to each other
by bent pieces of metal D; these pieces of metal are bent into an undulating
or corrugated form. The pieces of metal bent in this manner are arranged·
in a vertical position, their surfaces being parallel to the concentric tubes A
and C, the corrugations of the intervening pieces extending from one tube to
the other. The tubes A and C are attached to each other by soldering or
otherwise fastening the pieces of metal D at the parts where the curved line
touches either tube, as shown in the Plan, Figure 3, of my Drawing. Both
the upper and lower edges of the outer tube C are spread outwards, forming
funnel-shaped or trumpet-mouthed openings whereby the ingress of the air at

page_text: the lower opening and the egress of the smoke at the upper is facilitated.
The inner tube A has soldered or otherwise attached to it at equidistant
intervals four strips of metal E; these strips of metal are bent outwards over
the upper edge of the tube A, and are then curved upwards and towards the
centre of the tube. To the strips of metal E is riveted or otherwise secured
thereto an open metal cone F, which is arranged with its smaller open end
upwards. This cone F is supported by the strips of metal E at a short
distance above the main tube A, so that an ample space for the egress of the
smoke is allowed between the upper edge of the tube A and the lower edge
of the cone F, as well as the direct upward passage through the open smaller
end of the cone F. In this arrangement of the chimney can or top, when
the wind blows over the top of the outer tube C, and in a downward direction,
the smoke is not driven down the chimney because the downward gust of
wind finds ample egress beneath the lower edge of the larger tube C, the
column of smoke meanwhile ascending either through the open upper end of
the cone F or between its lower edge and the extremity of the central tube A..
In cases where chimnies are particularly exposed to sudden gusts or down-
ward currents of wind, the arrangement of the improved chimney can or top
may be modified, as shown in Figures 2 and 3 of my Drawing. This modi-
fication consists in the addition of a metal plate G suspended at a short
distance below the upper opening of the cone F. The plate G is supported
by riveting or otherwise securing it to the inner ends of the strips of metal E,
which for that purpose are prolonged inwards beyond their junction with the
cone F. The area of this plate G is equal or thereabouts to that of the
opening in the upper end of the cone F. The effect of this additional plate
is, that however violent the downward current or gust of wind may be, the
plate or disc G effectually prevents the smoke from being forced back and
down the chimney. The current of wind, being checked and deflected by the
cone F and plate G, escapes beneath the outer encircling tube C, the smoke
making its way out beneath the lower rim of the cone. The current of
heated air which ascends with the smoke as it passes up the chimney produces
a sufficient draught through the outer tube C as to ensure the smoke passing.
off unimpeded.
Having now described and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be used or carried
into effect, I may observe, in conclusion, that I do not confine or restrict
myself to the precise details or arrangements which I have had occasion to
describe or refer to, as many variations may be made therefrom without
deviating from the principles or main feature of my Invention; but what I

page_text: consider to be novel and original, and therefore claim as the Invention secured
to me by the herein-before in part recited Letters Patent, is,-
First, the general arrangement and construction of chimney cans
apparatus for promoting draught in chimnies, as herein before described.
Second, the system or mode of preventing downward or back draughts in
chimnies by means of chimney cans or tops arranged as herein-before
described, or any mere modification thereof.
Third, the use and application in and to chimney cans or tops of a metal
cone arranged above the tube or pipe through which the smoke passes, and
within an outer tube or casing, as herein-before described.
Fourth, the use and application in and to chimney cans or tops of a disc or
plate arranged within a cone to prevent the smoke from being checked in its
egress or driven back by sudden downward currents or gusts of wind, as
herein-before described.
In witness thereof, I, the said William Sandilands, have hereunto set my
hand and seal, this Twenty-sixth day of March, One thousand eight
hundred and fifty-eight.
WILLIAM SANDILANDS. (L.S.)