AN IMPROVED CHIMNEY CAP OR TOP, APPLICABLE ALSO TO VENTILATING SHAFTS
Year: 1878

page_text: LETTERS PATENT to Elkanah Church, of Beckenham, in the County of Kent,
Ironmonger, for the Invention of "AN IMPROVED CHIMNEY CAP OR TOP,
APPLICABLE ALSO TO VENTILATING SHAFTS."
Sealed the 20th December 1878, and dated the 19th October 1878.
PROVISIONAL SPECIFICATION left by the said Elkanah Church at the Office
of the Commissioners of Patents on the 19th October 1878.
ELKANAH CHURCH, of Beckenham, in the County of Kont, Ironmonger.
IMPROVED CHIMNEY CAP OR TOP, APPLICABLE ALSO TO VENTILATING SHAFTS."
"AN
This Invention consists in the construction of an improved chimney cap or top
for the prevention of down draught in chimneys, and for creating an upward
current in the same, the action being automatical. The cap or top is also applicable
to ventilating flues or shafts for the purpose of creating an upward current.
The improved cap or top consists of an inner and outer case of sheet metal, the
inner case being square at the base and round at the top, and the outer case octa-
gonal in form. The two cases are covered by a rounded top, in which is a round
central hole for the exit of the smoke, and over this hole is placed a cap or cover
flat on its under side and round on its top; this top prevents down draught and
yet allows the smoke to pass out through the space between the under side of the
cap and the hole. The space between the outer and inner cases is made to form a
chamber of motionless air, which is effected by putting a partition between the
bottom and top, which partition also forms a cover for four smaller additional holes
or exits for the smoke, which are made in the bottom, conducting the smoke out
between the inner and outer cases, and behind four sides of the octagonal case.
Then there are four square openings cut in the lower part of the other four sides
....A

page_text: of the octagon, through which a draught or current is created, having identical
action to that on the top. Below these four openings is fixed the necking piece
connecting the cap and its funnel together, which is made to fit any sized chimney
pot.
By this construction it will be seen that I obtain five separate outlets for the
smoke, each having a cover of its own on its top, and each opening from its con-
struction effectually prevents the possibility of down draught, yet at the same time
creates an upward current in connection with a motionless air chamber, which
becomes heated in use so as to rarefy the air and dispel fogs and vapours from the
cap, and thereby encourage the exit of the smoke.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Elkanah Church in the Great Seal Patent Office on the 16th April
1879.
ELKANAH CHURCH, of Beckenham, in the County of Kent, Ironmonger.
IMPROVED CAP OR TOP, APPLICABLE ALSO TO VENTILATING SHAFTS."
"AN
My said Invention is an improved cap or top for fixing to chimneys or ventilating
shafts for the purpose of creating a strong upward current, and preventing a down-
ward draught, which top is automatical in its action, inasmuch as it does not depend
upon any rotary motion to effect its purpose (namely) to raise and expel smoke
and viciated air, neither does it depend entirely upon the action of the wind upon
it to carry on its work, it being provided with two chambers of motionless air
hermetically sealed, so that the fumes rising up the chimney or shaft serve to rarify
the atmosphere, heat these chambers, and dispel the mist and fogs which would
otherwise obstruct the exit of the smoke, so that the improved top being necessarily
acted upon by either wind or heat (or both) it is always ready for its work.
It consists of an outer and inner case or tube, the outer one octagonal in form,
and the inner one square, the space between the two forming a chamber of motion-
less air surrounding the inner square and closed in with a separate top and bottom,
but this said chamber only reaches part of the way down the said case, the lower
part being occupied by the base of the inner square tube, which tube has four
rounded projections, which parts also form the bottom of the octagonal case; this
said bottom is made of cast iron or other metal cast in one piece, and in some cases
is made to rise in the manner herein-after described. The other portions of this
said improved top are made in sheet iron or other sheet metal.
There are openings cut in the lower part of four of the sides of the octagonal
case, and also four openings in the said cast bottom on the horizontal line behind
the other four sides of the octagonal case, so that the smoke or viciated air passing
up the shaft through these openings behind the said four sides of the octagonal case
is forced out at the openings on the opposite sides.
On the top of this outer octagonal case is fixed a rounded top with a round
hole in it, forming the large central exit for the smoke. Over this is placed a cap
or cover with a rounded top and conical point rising from its centre, which is
rivetted to same, and this cover is closed in with a perfectly flat bottom or under
side, which forms it into another chamber of motionless air, which is heated in the
same manner as the other before named.
By this arrangement it will be seen that I obtain a top or cap containing five
separate openings (or exits for the smoke) on the horizontal line, and that each of
the said openings are covered by a hot or motionless air chamber, having a perfectly
flat bottom, and also each of the said openings are acted upon by the outer air or
wind in precisely the same manner, producing a compound action. I also obtain
nearly twice as much area of opening as there is in an ordinary chimney pot.
And in order that my said Invention may be fully understood, I have illustrated
it in the annexed Drawings, and will now proceed to particularly describe the
same.
The same letters indicate the same parts in all the Figures.
Figure 1 is a side elevation of my improved chimney cap or top applicable to
ventilating shafts.
Figure 2 is a vertical section of the same shewing the internal arrangement of
its parts.
Figure 3 is a Drawing to shew the bottom part of the before-named inner square
with its projections C, D, and its connection with the top A by means of the
rods E, E. These two parts are made to lift up by the sweep's machine (when
applied to chimneys, so that the brush passes out above D, Figure 1, and the parts
C, D, by rising, clean the openings F, F.

page_text: Figure 4 is a plan or horizontal section of the top taken along the line 1-2, in
(Figure 1).
The arrows in (Figure 1) denote its action. The wind or air impinging upon either
of the rounded surfaces D, D, D, D, D, is deflected against the plane flat surface of
the cover from which it strikes off at right angles, which action produces an upward
current in three of the said openings, over which it passes at the same time from
whatever direction the wind may be blowing. The arrows in (Figure 2) denote
the course of the smoke or vitiated air as it is operated upon by the suctionary
power of the Invention; L is the top of the hot air chamber.
B (in Figure 1) is the octagonal case herein-before referred to with its rounded top
and cover, resting on four tubular supports, through which two of the rising rods
E, E, (Figure 3,) pass; G is the neck or connecting piece rivetted to the shaft M.
The dotted portion (in Figure 2,) H, H, H, shews the hot air chambers.
I wish it to be understood that I do not limit myself to the sizes and proportions
shewn, as it is obvious that they may be somewhat modified, enlarged, or varied
according to circumstances, as may be found necessary without affecting the
principle of the Invention, but the proportion given is that most generally suitable
in practice, more particularly for smoky chimneys.
Having now described and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be used, I would observe
in conclusion that what I 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 improved form of top for chimneys, also applicable to ventilating
shafts, having an outer octagonal case and inner square tube with a rising base.
Second. The introduction and formation of hot air chambers therein.
Third. The arrangement of five separate openings on the horizontal line, each being
covered by a chamber of motionless air, and each of the openings being acted upon
alike.
Fourth. The combination of the several parts and the general construction, sub-
stantially as herein-before described and illustrated in the Drawings annexed.
In witness whereof, I, the said Elkanah Church, have to this my Specification
set my hand and seal, this Fourteenth day of April, in the year of our
Lord One thousand eight hundred and seventy-nine.
ELKANAH CHURCH
(2.9)