IMPROVE- MENTS IN VENTILATORS
Year: 1877

page_text: LETTERS PATENT to James Mac Lauchlan Dobson, of Glasgow, in the County
of Lanark, North Pritain, Sanitary Inspector, for the Invention of "IMPROVE-
MENTS IN VENTILATORS."
Sealed the 14th May 1878, and dated the 1st December 1877.
PROVISIONAL SPECIFICATION left by the said James Mac Lauchlan
Dobson at the Office of the Commissioners of Patents on the 1st December
1877.
JAMES MAC LAUCHLAN DOBSON, of Glasgow, in the County of Lanark, North
Britain, Sanitary Inspector. "IMPROVEMENTS IN VENTILATORS."
"
This Invention relates to an improved construction or constructions of stationary
or non-revolving lateral action hood or cowl ventilators, for the tops of chimneys,
shafts, or pipes for the ventilation of houses and other buildings or chambers, ships,
mines, waterclosets, drains, and sewers, which ventilator_acts more uniformly and
efficiently, from whatever direction the wind or outer air may be blowing, at the
same time being more simple and cheap in construction than those heretofore
in use.
And the nature and novelty of the Invention consist in forming within the hood,
between the throat or neck and the close or other top, as set of 4, 6, 8, or any
greater even number of curved or angled vanes or divisions radiating from tho
centre, the termination of the radii of these divisions being rounded or curved seg-
mentally, preferably of a Gothic shape, so that the diametrically opposite radius of
each division would give the appearance of an S, leaving a vertical space between
the end of each S curve and the adjacent radii of about a third of the whole space
between them for the exhaust or discharge of the air and gases up the central shaft
and chamber of the ventilator; and although the ends of the division vanes have
been described as curved they may be formed of nearly straight lines of a V shape,
with the apex outwards.

page_text: Opposite each alternate curved or angled division, and at a sufficient distance
from it to allow the outward current of gases to pass, an inwardly angled or curved
protecting plate or deflector is placed, with its free ends preferably curved out-
wards, and long enough to prevent the outer air curients from entering direct
through the open outlet spaces on each side of the curved division. And another
outwardly curved or angled plate opposite the intermediate curved divisions is also
placed at sufficient distance from the curved divisions, and the ends of the former
or protecting plate to allow the outer air deflected off the protecting plate to pass
across the ends of these curved or angled divisions, and so by its lateral action draw
the internal foul air or gases from the inner divisions, out through between both
sets of deflecting plates on the opposite side to that from which the wind or outer
air current is blowing, the extreme ends of these outer plates overlapping or reaching
considerably beyond those of the inner plates, and angled on their inner surface
sufficiently to deflect the air into the spaces between them and the inner plates or
protectors, and also form protecting plates, and prevent the wind coming in the
direct line of these divisions and plates from entering the two spaces immediately
behind them, thus making all the spaces draw and discharge the foul air or gases by
the lateral action of the outward air current, and giving more regular and equal
acting area of ventilation from whatever point of the compass the wind is blowing;
and the hollow outsides of the outer protecting or deflecting plates might be filled or
covered in so as to give the whole hood a more symmetrical, round, or polygonal
shape, surmounted by a conical or ornamental top or cover, the lower throat or open
end of the hood being tapered or funnel-shaped towards the socket, which is shipped
and fixed on to the shaft or column to be ventilated substantially as other hoods
are.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said James Mac Lauchlan Dobson in the Great Seal Patent Office on the
31st May 1878.
JAMES MAC LAUCHLAN DOBSON, of Glasgow, in the County of Lanark, North
Britain, Sanitary Inspector. "IMPROVEMENTS IN VENTILATORS.'
"2
My said Invention relates to improved constructions of stationery or non-
revolving lateral action hood or cowl ventilators, for the tops of chimneys, shafts,
or pipes, for the ventilation of houses and other buildings, or chambers, ships,
mines, waterclosets, drains, and sewers, which ventilators act more uniformly and
efficiently from whatever direction the wind or outer air may be blowing, at the
same time being more simple and of cheaper construction than those heretofore
in use.
And in order that the nature, novelty, and mode of performing my said Invention
may be properly understood, I shall now proceed to describe the several Figures
on the Sheet of Drawings which I have hereunto appended for that purpose, the
same reference letters indicating the same parts in the several Figures.
Figures 1 and 2 on the accompanying Drawings are a vertical section and a
sectional plan, the former taken on the line a--a of the latter, showing one modifi-
cation of my ventilating hood.
Figures 3 and 4 are a side elevation and a sectional plan respectively of a
slightly different modification from that shown in Figures 1 and 2 of my ventilating
hood or cowl, while Figure 5 is a sectional plan showing a modification of my
ventilating cowl or hood, substantially the same as that shown in Figure 3, but
without the central vanes d' and divisions d, and acting in like manner, the passage
of the ventilating currents of outer air and the fowl air or gases being represented
by the arrows and the darts respectively in all the Figures
Referring to Figures 1 to 4, my said Invention consists in forming within the
hood A, between the throat B' of the neck B and the close or outer top C, a set of
4, 6, 8, or any greater even number of curved or angled vanes d, and divisions or
spaces d radiating from the centre, the termination of the radii of these divisions
d being rounded or curved segmentally, preferably of a Gothic shape, as seen par-
ticularly in Figure 2, so that the diametrically opposite radius of each division or
space would give the appearance of an S, leaving a vertical space dº between the
end of each S curve and the adjacent radii of about a third of the whole space
between them for the exhaust or discharge of the air and gases up the centre throat
and shaft B', and spaces d', D, between these and the outer division or directing
plates D¹ of the ventilator A. Although the ends d³ of the division vanes d have
been described as curved, they may be formed of nearly straight lines of a V shape,
with the apex outwards, as seen at in Figure 4.
Opposite the end d³ of each alternate curved or angled vane d, d², and a sufficient
distance from it to allow the outward current of gases to pass, the inwardly angled
or curved protecting plate or deflector D¹ is placed with its free ends preferably long
enough to prevent the outer air currents from entering direct through the open
outlet spaces d¹¹, on each side of the curved divisions d. An outwardly curved or
angled plate D, opposite the intermediate curved or angled and open spaces D", is
also placed at sufficient distance from the curved divisions and the ends of the
former or protecting plate D¹, to allow the outer air, deflected off both these plates
D', D, to pass along the ends of these curved or angled divisions D', and so by its
lateral action draw the internal fowl air or gases from the inner spaces d', out
through between both sets of deflecting plates D', D³, on the opposite side to that
from which the wind or outer air current is blowing, as seen particularly by the
arrows and darts in Figures 2, 4, and 5, the extreme ends of these outer plates Dº
overlapping cr preferably reaching considerably beyond those of the inner plates D¹,
and angled on their inner surface sufficiently to deflect the air into the spaces D

page_text: and D, between them and the inner plates or protectors D¹, which also form pro-
tecting plates to prevent the wind coming in the direct line of the divisions or spaces
forined by the ends of the plates d, from entering the two spaces d" immediately
behind these plates D¹. The plates D' also divide the air and gases passing along
the face of the plate D³ into two currents, one of which currents passes along the
spaces at the rear side of the ventilator, thus making all the spaces draw and
discharge the foul air or gases by the lateral action of the outward air current, and
giving more regular and equal acting area of ventilation, from whatever point of
compass the wind is blowing. The hollow outsides of the outer protecting or deflecting
plates D might be filled or covered in so as to give the whole hood A a more
symmetrical, round, or polygonal shape, surmounted by a conical or ornamental top
or cover C, and the lower throat B¹ and open end B of the hood A may be tapered or
funnel-shaped to form a socket, which is shipped and fixed on the shaft or column
to be ventilated, substantially as other hoods arc.
Having now described the nature of my said Invention, and the manner of per-
forming the same, I have to state that I do not confine myself to the precise details
herein described or delineated, but what I consider novel and original, and therefore
claim as the Invention secured to me by the herein-before in part recited Letters
Patent is, the general construction and combination of the parts of ventilating
hoods or cowls, with inner curved or angled vanes d or d and openings d', d¹¹, with
outer protecting and deflecting plates D³, D³, the former for deflecting the currents
in two directions to give universal extracting power throughout the whole aren
of the hood, all substantially as herein described in reference to and shown in
the accompanying Drawings, or any mere modification thereof.
In witness whereof, I, the said James Mac Lauchlan Dobson, have hereunto
set my hand and seal, this Thirtieth day of May, in the year of our
Loid One thousand eight hundred and seventy-eight.
Witness,
JOHN BROWN,
Patent Agent,
Glasgow.
JAMES MOLACHLAN DOBSON. (L.S.)