Improvements in Ventilators and Chimney Cowls.
Year: 1892

page_text: Date of Application, 23rd Apr., 1892
Complete Specification Left, 20th Jan., 1893—Accepted, 25th Feb., 1893
PROVISIONAL SPECIFICATION.
Improvements in Ventilators and Chimney Cowls.
I, ROBERT MUSHET of 113 Duke Street Glasgow Lanarkshire Sheet Metal
Worker do hereby declare the nature of this invention to be as follows
--
This invention has reference to and comprises improvements in the construction
of ventilators of the hooded class, principally intended for use on board ship, but
applicable also to ventilators for general purposes, and to chimney cowls; and
has for its object the increased efficiency in such ventilators and chimney cowls by
improving the draught, through the greater velocity given to the air currents.
One arrangement of improved ventilator intended in this case for discharging
vitiated air or other gases from places to be ventilated by an outward current,
consists in forming the upper part of the usual hooded or cowl construction resting
upon a cylindrical or suitable shaped body or lower part, but instead of as is
ordinarily the case, having the edges of the mouth part turned out similar to a
trumpet mouth, it would be fitted with an improved nozzle arrangement to be
hereinafter described.
The mouth of the hood whether formed circular elliptical or other suitable
shape in contour, would have an inner ring or mouthpiece either of sheet metal
or of cast metal formed to the required shape of said hood and secured to it by
screws or rivets.
This mouthpiece is so formed that its opening is somewhat smaller in diameter
and may be excentric to that of the hood; that is its centre may be closer to the
upper part of the hood than to its lower, and projects beyond the hood and is
angled or bevelled inwards. Around this mouthpiece is formed a small groove or
gutter to catch and prevent from passing down the ventilator any rain or drift
water which may enter it, and the inside of this mouthpiece is preferably formed
angled or sloping downwards from the said groove at the bottom part to allow the
water to run out of same but on the top it is preferred to have it nearly straight.
This mouthpiece might be made plain without any groove or the mouth of the
hood might be angled inwards to form the mouthpiece or inner side of the annular
nozzle.
Around this mouthpiece short metal stays are formed or fitted, or these stays
might extend direct from the hood on to which would be rivetted or screwed a
conoidal or suitable shaped ring or nozzle of sufficient length to extend from
behind the mouthpiece to some distance in front of it, and may be formed so as
to have a more acute angle or be parallel with the angled outside of the said mouth-
piece or so as to form any angle therewith, so that the annular passage thus formed
around the mouth of the hood, would be narrower at the front than at the back.
On the hood being set with its back to the wind, the wind entering at the back
of the annular passage would be compressed and caused to converge in a conically
formed current where it would be concentrated creating a partial vacuum behind
it, and in the mouth of the ventilator, which would thereby suck or cause to
flow out the vitiated air or other gases which might be within the place being
ventilated.
This conoidal ring or nozzle also acts as a guard against side winds drift water
or rain entering the ventilator by the mouthpiece.
This form of ventilator would serve equally well as a chimney cowl to promote
up draught in chimneys, in which case it would be mounted much as usual on a
spindle and be fitted with a vane or wings on its upper part to keep the mouth
always turned away from the wind. The conoidal ring or nozzle assisting in this
operation.

page_text: Another improvement applied to this arrangement consists in the method of
securing the hooded part to its lower or cylindrical body part. This is effected by
securing to the lower part of the hooded portion, by hinges drop catches that are
preferably weighted at their lower ends which take on by a hooked or turned claw
on their under side, to a projecting ring on the lower body part, so that when the
upper or hooded part of the ventilator was passed down over the cylindrical body
part, the claws being weighted at their lower ends take on to the projecting ring or
any suitable projections or openings formed on the body part at once securing both
parts together.
These drop catches in some cases might be formed with circular eyes or elliptical
slots at their lower ends to take on to studs secured to the lower or body part of
these ventilators.
"
If desired these ventilators may be fixed to the places to be ventilated, with any
usual or ordinary catches.
For ventilators which are intended to promote a down draught such as are used
on board ship to supply air to the engine and boiler rooms or other parts the
conoidal ring or nozzle as described instead of being fitted on the outside of the
mouth of the ventilator is reversed and fitted inside of same, and would be formed
so as to converge the current of air inwards, when the mouth of the ventilator was
turned to the wind, in this case the mouth of the ventilator would preferably be
bell mouthed or trumpet shaped; some distance below the hood an annular gutter
might be fitted in the inside of the lower cylinder part or it might be on the upper
part having small openings to the outside to catch and discharge any rain or spray
which might be blown in and on to the sides of ventilator.
Dated this 21st day of April 1892.
ROBERT MUSHET.
COMPLETE SPECIFICATION.
Improvements in Ventilators and Chimney Cowls.
I, ROBERT MUSHET of 113 Duke Street, Glasgow, Lanarkshire, Sheet Metal
Worker, do hereby declare the nature of my invention and in what manner the
same is to be performed, to be particularly described and ascertained in and
by the following statement in writing reference being had to the accompanying
drawings, that is to say :-
This invention has reference to and comprises improvements in the construction
of ventilators of the hooded class, principally intended for use on board ship, but
applicable also to ventilators for general purposes and to chimney cowls, and has
for its object the increased efficiency in such ventilators and, chimney cowls by
improving the draught, through the greater velocity given to the air currents.
And in order that my invention may be properly understood I have hereunto
appended two explanatory sheets of drawings in which the same reference letters
are used to indicate corresponding parts in all the figures where shown.
Referring to Sheet 1 of these drawings Figure 1 is a side elevation of my ventilator
as specially applicable for use on board ship, and Figure 2 is a sectional view of
same, while Figure is a front view of the conoidal ring and mouthpiece,
Figure 4 is a detail side view representing one modification of ring and mouthpiece
as applied to downdraught ventilators specially for use on board ship, while
Figure 5 is a detail view of gutter for discharging rain or spray from the inside of
the ventilator, while Figure on Sheet 2 is a side elevation of chimney cowl with
improvements applied, for promoting updraught in chimneys, Figure 7 is a sectional
view of same, and Figure 8 is a detail side and front view of a modification of
securing catches as applied to chimney cowls.
One arrangement of improved ventilator intended for discharging vitiated air or
other gases from the places to be ventilated by an outward current, consists-as
shown in Figures 1 and 3, as applied to ships ventilators,-in forming the upper

page_text: part A of the usual hooded or cowl construction, resting upon a cylindrical or
suitable shaped body or lower part A'; but instead of as is ordinarily the case
having the edges of the mouth part turned out similar to a trumpet mouth, it
would be fitted with an improved nozzle arrangement to be hereinafter described.
The mouth of the hood whether formed circular, elliptical or other suitable
shape in contour, would have an inner ring or mouthpiece B, either of sheet metal
or of cast metal formed to the required shape of said hood and secured to it by
screws or rivets. This mouthpiece B is so formed that its opening B', is somewhat
smaller in diameter and may be excentric to that of the hood as seen particularly
in Figure 3 Sheet 1 :-That is its centre may be closer to the upper part of the
hood than to its lower, and projects beyond the hood and is angled or bevilled
inwards. Around in the inside of this mouthpiece B, is formed a small groove or
gutter to catch and prevent from passing down the ventilator any rain or drift
water which may enter it. And the inside of this mouthpiece B is preferably
formed angled or sloping downwards from the said groove b at the bottom part b¹ to
allow the water to run out of same, but on the top at 63 it is preferred to have it
nearly straight.
Around this mouthpiece B short metal stays c are formed or fitted or they
might extend direct from the hood, on to which would be rivetted or screwed a
couoidal or suitable shaped ring or nozzle C, of sufficient length to extend from
behind the mouthpiece B and to some distance in front of it-or it might be flush
with said mouthpiece-and be formed so as to have a more acute angle or be
parallel with the angled outside of the said mouthpiece B, or so as to form any
angle therewith so that the annular passage thus formed around the mouth B¹ of
the hood A. would be narrower at the front than at the back.
On the hood A being set with its back to the wind, the wind entering at the
back of the annular passage would be compressed and caused to converge in a
conically formed current where it would be concentrated thus creating a partial
vacuum behind it and in the mouth B' of the ventilator A, A', which would thereby
suck or cause to flow out the vitiated air or other gases which might be within the
place to be ventilated.
This conoidal ring or nozzle C also acts as a guard against side winds, drift
water, or rain entering the ventilator A, A', by the mouth B'.
On referring to Sheet 2 of the accompanying drawings, Figures 6 and 7, it will
be seen that this form of ventilator would serve equally well as a chimney cowl to
promote up-draught in chimneys, in which case the hood A, would be mounted
much as usual on a spindle D, and be fitted with a vane or wings E, on its upper
part to keep the mouth 1, always turned away from the wind, the conoidal ring or
nozzle C, assisting in this operation.
The mouthpiece B, might be made plain without any groove or the mouth of the
hood A, might be angled inwards to form the mouthpiece B, or inner side of
the annular nozzle.
In order to battle and disperse any wind that might find its way into the mouth
of the chimney cowl, I fit preferably a concave circular battle plate D', on the
spindle D, a little below the level of the bottom of the mouthpiece B of the cowl
to deflect any wind finding its way into the hood A of the chimney cowl A, A',
as shown particularly in Figure 7, Sheet 2 of the accompanying drawings.
Another improvement applied to this arrangement, consists in the method of
securing the hooded part A, to its lower or body part A', which improvement
allows of the easy removal of the hooded part A for cleaning, and the automatic
securing of same when replaced.
This is effected by securing to the lower part of the hooded portion A by
hinges F, drop catches F1, that are preferably weighted at their lower ends, which
take on by a hooked or turned claw on their underside, to a projecting ring a on
the lower body part. A', so that when the upper or hooded part A, of the
ventilator was passed down over the cylindrical body part A', the claws f
being weighted at their lower ends take on to the projecting ring a or any suitable

page_text: projections or openings formed on the body part A¹ and at once securing both parts
together. These drop catches F night in some cases as shown in Figure 8 Sheet 2
be formed with circular eyes or elliptical slots at their lower ends to take on
to studs a secured to the lower or body part A¹; the stud a' being in this
case shown in the side view; as in its horizontal unsecuring position, but in the
front view as in its vertical secured or locked position.
If desired these improved ventilators may be fixed to the places to be ventilated
by any of the usual securing methods commonly in use.
For ventilators-as shown in Figure 4 Sheet 1 of the accompanying drawings—
which are intended to promote a down draught, such as are used on board ship to
supply air to the engine and boiler rooms or other parts, the conoidal ring or
nozzle C, as described instead of being fitted on the outside of the mouth B of
the ventilator is reversed and fitted inside of same, and would be formed so as to
converge the current of air inwards, when the mouth of the ventilator was turned
to the wind, in this case the mouth B of the ventilator would preferably be bell
mouthed or trumpet shaped.
Some distance below the hood A an annular gutter G as shown in detail,
Figure 5 Sheet 1 of the drawings might be fitted on the ventilator A, A¹, having
small openings y to the outside with baffle ring g' to catch and discharge by said
openings g any rain or spray which might be blown in and on to the sides of the
ventilator A, A¹.
Having now particularly described and ascertained the nature of my inven-
tion and in what manner the same is to be performed I declare that what 1
claim is :-
First. The herein described improvements in the construction of ventilators and
chimney cowls consisting in the fitting of same with short convidal rings or nozzles
around the ordinary hoods either inside or outside their mouths, also with rain or
spray collecting and discharging gutters, and drop catches or hooks, all substantially
as and for the purposes herein described and illustrated by the various figures of
the accompanying drawings.
Second. The construction and use of ventilators or chimney cowls having hoods
fitted with contracted mouth-pieces and short conoidal rings or nozzles around the
outside of their mouths for the purpose of assisting the exhaustion of the air from
same all substantially as herein described and illustrated by Figures 1, 2, 3, 6, 7, of
the accompanying drawings.
Third. The construction and use of ventilators having short conoidal rings or
nozzles fitted within their mouths for the purpose of assisting the induction of the
air all substantially as herein described and illustrated by Figure 4 of the accom-
panying drawings.
Fourth. The fitting of ventilators and chimney cowls with drip, rain, or spray
intercepting and discharging gutters, all substantially as herein described and
illustrated by Figure 5 of the accompanying drawings.
Fifth. The fitting of ventilators and chimney cowls with hinged or pivotted
drop catches on their hooded parts, taking on to the lower part of said ventilators
or chimney cowls all substantially as herein described and illustrated by Figures 6
to 8 of the accompanying drawings.
Dash: 19th January 1893