IMPROVEMENTS IN OR RELATING TO EXHAUST VENTILATORS OR CHIMNEY TOPS
Year: 1883

page_text: LETTERS PATENT to William Walker of Birkenhead in the County of
Chester for an Invention of "IMPROVEMENTS IN OR RELATING TO EXHAUST
VENTILATORS OR CHIMNEY TOPS"
PROVISIONAL SPECIFICATION'left by the said William Walker at the Office
of the Commissioners of Patents on the 15th November 1883.
WILLIAM WALKER of Birkenhead in the County of Chester
IN OR RELATING TO EXHAUST VENTILATORS OR CHIMNEY TOPS
"
"IMPROVEMENTS
This invention has for its object a ventilator top, or chimney top, that no matter
in which way the wind blows an induced current will be formed, tending to suck
up the air out of the ventilating shaft or chimney, and consists namely in providing
corrugated surfaces or ducts capable of directing the wind in an oblique direction
past the orifice.
Any one or more parts of my ventilator, or chimney top, could be applied with
advantage to existing chimney tops, but when they are applied together as a
complete top they give the most advantageous result.
The shaft or body of the chimney top is made preferably corrugated or channelled,
but other existing types could be utilized. A conical corrugated hollow truncated
cone is placed round the shaft. If the corrugations be deep enough this can be
placed round a smooth cylindrical shaft with great advantage, but as said before a
corrugated shaft is better. The two sets of corrugations should correspond to
and be opposite the external convexities of the other; by this means a large
amount of space is left for air to pass up between each corrugation of the shaft and
cone. Any number of corrugated cones can be applied one above the other, the
corrugations of all being equal in number to those of the first, and the internal--
convexities of each upper one abut against the external convexities of the one
immediately below. A corrugated conical cap supported on rods or pedestals
projecting from the uppermost cone, surmounts the whole. The corrugations on
this disc all radiate from the centre, their upper apices or salient corrugations
being in a horizontal plane forming a more or less obtuse cone. The various parts

page_text: are rivetted, bolted, brazed, or otherwise fastened together in any usual manner,
and the apparatus can be made of wrought iron, or with suitable alteration of
earthenware or other material adapted for making chimney tops.
The mode of action is as follows:
The wind blowing horizontally, or in a slightly upward direction, strikes against
the shaft or cones and is deflected upward. It passes up the corrugations into the
central vent, and so induces an upward current in the latter. Wind striking
against the cap rushes down the corrugations on the opposite side, and past the
opening between the cap and the uppermost cone, inducing an outward current
from the central vent while at the same time the cap keeps out the rain or hail 1
that would otherwise fall into the chimney or shaft.
In speaking of cones throughout I am of course aware that pyramids would also
answer the same purpose to a limited extent, and I wish it to be understood
throughout this Specification that the word "pyramid is understood to be
included in the word "cone," similarly "corrugated" must be held to include the 1
word "channelled."

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Walker in the Patent Office on the 14th May 1884.
WILLIAM WALKEB, of. Birkenhead, in the County of Chester,
IN OR RELATING TO EXHAUST VENTILATORS OR CHIMNEY TOPS
11
" « IMPROVEMENTS
This invention has for its object a ventilator top or chimney top that, no matter
in which way the wind blows, an induced current will be formed tending to suck
or force upwards the air out of the ventilating shaft or chimney; and consists
namely in providing corrugated surfaces or ducts capable of directing the wind in
an oblique direction into or past the orifice.
In the drawings :—
Fig 1-shows a sectional elevation of my chimney top in its most complete
form.
Fig 2-plan of same. Any one or more parts of this ventilator can be applied.
In the drawings, A is the shaft or body of the chimney top, made preferably
corrugated or channelled, but other existing types could be utilized. B is a conical
corrugated hollow truncated cone placed round A The two sets of corrugations
should correspond, so that the internal convexities of the one should be opposite
the external convexities of the other; by this means a large amount of space is left
for air to pass up between the two parts A and B at each corrugation. C is a
second and similar cone. Any number of corrugated cones can be thus applied
one above the other, the corrugations of all being equal in number to those of B,
and the internal convexities of each upper one abut against the external convexities
of the one immediately below. D is a corrugated conical cap, supported on rods or
pedestals E, projecting from the uppermost cone surmounting the whole. The
corrugations on this disc all radiate from the centre, their upper apices or salient
corrugations being in nearly a horizontal plane, as shewn, or forming a more or less
obtuse cone. The various parts are riveted, bolted, brazed, or otherwise fastened
together in any usual manner, and the apparatus can be made of wrought iron, as
in the one shown in the drawing, or, with suitable alteration, of earthenware, or
other material adapted for making chimney tops.
The mode of action is as follows.
The wind blowing horizontally, or in a slightly upward direction, strikes
against A, B, or C, and is deflected upward. It passes up the corrugations into
the central vent, and so induces an upward current in the latter. Wind striking
against D rushes down the corrugations on the opposite side, and past the opening
between D and C, inducing an outward current from the central vent, while at the
same time the cap D keeps out the rain and hail that would otherwise fall into the
chimney or shaft.
In speaking of cones throughout I am of course aware that pyramids would also
answer the same purpose to a limited extent, and I wish it to be understood
throughout this specification that the word "pyramid" is understood to be
included in the word "cone," similarly "corrugated" must be held to include the
word "channelled."
Having now described my invention,_and_the_best mode known to me of
carrying it into effect, I wish it to be understood that what I desire to protect
under Letters Patent is
(1) The chimney or ventilator top arranged and constructed as a whole
substantially as described, and also the following separate parts of my invention
taken separately, or in conjunction with others, but always substantially as and for
the purposes described.

page_text: (2nd) The truncated hollow cone (B) fitted on the top of the shaft and having
spaces between its inner surface and the shaft end.
(3) The combination of two or more corrugated or channelled cones (B. C.)
having air spaces between them, and a ventilating or chimney shaft end.
(4th) The corrugated cap D.
. In witness whereof, I the said William Walker have hereunto set my hand and
seal this 12th day of May in the year of our Lord, one thousand, eight hundred and
eighty four.