IMPROVE- MENTS IN VENTILATING APPARATUS
Year: 1878

page_text: LETTERS PATENT to James Mac Lauchlan Dobson, of Glasgow, in the County
of Lanark, North Britain, Sanitary Inspector, for the Invention of "IMPROVE-
MENTS IN VENTILATING APPARATUS."
PROVISIONAL SPECIFICATION left by the said James Mac Lauchlan Dobson
at the Office of the Commissioners of Patents on the 4th July 1878.
JAMES MAC LAUCHLAN DOBSON, of Glasgow, in the County of Lanark, North
Britain, Sanitary Inspector. "IMPROVEMENTS IN VENTILATING APPARATUS."
This Invention has reference to the construction and arrangement of certain new
or improved apparatus for the ventilating of buildings, halls, factories, schools,
apartments, ships, mines, and railway carriages, or other close places where ventila-
tion is required, and which is more simple in construction, and efficient in action,
besides being more easily and cheaply applied than most of the ventilators hereto-
fore in use.
And the nature and novelty of the Invention consist in constructing the apparatus
in the form of an inner hollow truncated cone or nozzle, preferably made of sheet
metal, with a hollow or annular conical case round its outer surface, joined close
all round the base or wide part of the said first inner cone, which is upen right up
through to its truncated throat, where the outer conical case is contracted to a
narrow annular space all round it, and joined to the lower open end of a narrow
discharge tube, a little larger than the diameter of the truncated nozzle of the inner
cone (and either parallel or widening towards the discharge end) which is placed at
the top or ceiling of the apartment to be ventilated, so that the heated or lighter
air naturaly flows right up through this inner cone to and through the discharge
duct or shaft, assisted by a current of air paased up through the outer conical case
through a tube led into its lower or other side from the outer or other air blown
into it from the outside of the house or apartment to be ventilated, where an
expanding filler-shaped mouth-piece would be formed to assist the inlet of the
outer air.

page_text: And further, when desired, a current of cold or heated air or gases might be
forced or conducted through the said tube and outer annular case and throat, so as
to draw and force the vitiated or other air desired to be discharged through the
inner conical nozzle and discharge duct or funnel above it direct from the apart-
ment desired to be ventilated; the increased velocity of the air to be discharged
through the narrow throat of the new or improved apparatus obtained by this
means effectually insures the continuous discharge from and ventilation of the
apartment.
Although this apparatus has been described as round and annular in the hori-
zontal sections of the cones and ducts, it will be understood that it might also bo
made polygonal in plan when desired.
•
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 tho
27th December 1878.
JAMES MAC LAUCHLAN DOBSON, of Glasgow, in the County of Lanark, North
Britain, Sanitary Inspector. "IMPROVEMENTS IN VENTILATING APPARATUS."
My said, Invention has reference to the construction and arrangement of certain
new or improved apparatus for the ventilating of buildings, halls, factories, schools,
apartments, ships, mines, and railway carriages, or other close places where ventila--
tion is required, and which is more simple in construction, and efficient in action,
besides being inore easily and cheaply applied than most of the ventilators hereto-
foro in usc.
And in order that the nature, novelty, and mode of performing or making and
applying 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 letters and numerals indicating the same or
equivalent parts in all the Figures.
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Figure 1 is a vertical section, and Figures 2 and 3 are transverse sections on the
lines 2 2 and 3 3 of one modification of my new or improved nozzle venti-
lating apparatus, constructed in accordance with and illustrative of my said Invention,
for putting on the top and other exposed parts of pipes or ducts, and to be actuated
by the wind or outer air, for drawing off the impure air or gases from soil and
sewer pipes, and from the apartments of buildings and other places; or as a hood
or cowl for such up-take pipes, shafts, or chimneys for the improvement of ventilation
generally.
Figure 4 is a vertical section of a slightly different modification or construction
'of my said new or improved ventilator or nozzle hood from that shown in Figures 1
to 3, but substantially equivalent and for the like application and purposes.
Figure 8 is an outside vertical elevation of the ventilator shown in Figure 4,
but with an ordinary blow down preventing cowl 2 on the top, while Figures 5, 6,

page_text: and 7 are horizontal sections of the same ventilator and hood, taken on the corres-
ponding lines 4---4, 5-5, and 6---6 in Figure 4 & 8.
Figure 9 is a sectional elevation of a horizontal arrangement of my new or
improved ventilator, constructed for being fitted over the ceilings of rooms or other
places for drawing off the hot or foul air or gases therefrom, for being actuated by
forced air or other gases or vapour from any usual fanners or other fluid blowers or
forcing apparatus.
Referring to Figures 1 to 3, the construction of this modification and adaptation
of my said Invention and the nature thereof consist in constructing the apparatus
or ventilator with an inner hollow truncated cone or nozzles A, preforably made of
sheet metal, and in this case leading direct up froin the inlet duct or channel B or
from the apartment or place to be ventilated, and where the inlet hollow stem or
socket B is formed for fixing it to the top of the pipe leading therefrom; this inner
cone A, being surrounded by a close hollow outer case C jointed close all round the
base or wide part C¹ of the first inner cone A and duct B, which in this case is
open right up through to its truncated nozzle A³, noar where the outer conical case
C is contracted to a narrow annular space D all round it, and jointed to the lower
or inner open end E' of a narrow discharge tube E, a little larger in diameter than
that of the truncated nozzle A' of the inner conc A, and either parallel or widening
towards the discharge end E. And when this ventilator is placed on the top of a
pipe leading froin and above the roof or ceiling of the house or apartment to be
ventilated, the heated or lighter vitiated air naturally flows up through the inlet
duct B and cone A, A', as indicated by the darts in Figure 1, to and through the
discharge duct or top shaft E, assisted or drawn and forced by the lateral action of
a current of wind or air from the outside passed in through the annular spaces C
in the outer case C (indicated by the arrows) up through the inner case or nozzle
A, A', from the outer conical case C, and preferably made in the form of an
outward expanding filler-shaped mouth-piece, to assist the inlet of the outer or
other air blown or forced in through these openings C.; or otherwise, it might be
a current of air forced in through a tube or other duct as C, shown in dotted lines
at the lower side or other part C', into the outer case C, D, and forced by any
suitable air fanner or blowing machine. The darts and arrows in this and the other
Figures respectively indicate the course of the vitiated air and gases being drawn
off, and that of the air or other acting or inducing fluid through the channels, nozzles,
and ducts of these apparatuses or ventilators,
By another slightly different modification of my ventilator, shown in Figure 4,
the vitiated air to be drawn off is led up from the inlet channel B through the
annular nozzle or throat D, and the outer or forced air is led in through the
expanded ducts or mouths C" in the outer case C direct into the inner cone A, A³,
so that as it escapes at the nozzle A¹ it acts on and draws or forces out the bad air
or gases rising in the annular throat D, through the chamber D', and discharge
throat E, and outlet tube E.
These ventilators, Figures 1 and 4, when fitted on the top of soil or sewer pipes
or chimneys, for ventilating and producing outflow currents therefrom, are
preferably fitted or surmounted on top with any ordinary vaned, stationary,
swivelling, or rotating cowls, for preventing a blow down, as seen in Figure 4 and
8, the construction of which is very clearly seen by the several horizontal sections
shown in Figures 5, 6, and 7; and when a forced air current is used for the lateral
acting fluid, a tube or duct, as C³, shown in Figure 1, may be used in the modifi-
cation shown in Figures 4 and 8 to lead the drawing and forcing-in fluid from the
blower, through the outer case C and space D, into the lower part of the inner cone
nozzle A, A¹, instead of the openings C¹¹.
To prevent any rain water or melted snow (which may get through the top cow!
into either the inner cone A, A, or the outer case C, C, D, of these ventilators,
Figures 1 to 3 and 4 to 8 respectively) getting down the inlet or drawing-off pipe
or duct B, I prefer to make this pipe or neck duct B to project a little up into these
cones or cases A and C at B¹ either with or without the larger projecting cone d

page_text: above it, and so as to form a collecting receiver, with a small escape tube or duct at
the lowest part b, with a water-luted syphon or overflow trap b' outside, for
conveying away the water collected inside, without admitting air or preventing the
proper action of the ventilator as described.
Referring to Figure 9, this shows the action of two new or improved ventilators,
A, B, C, at 1 and 2, as drawing off the vitiated air and gases by their respective
expanding or filler-shaped inlet ducts Cinto the outer cases C, near the back or
inner closed-in end C of the annular space D, from two parts of the ceiling of a
large hall, or it might be two different apartments of a house, or other parts or
places to be ventilated, and, as indicated by the darts in the Figure, the long
connecting tubes or ducts B2, B3, connecting the two ventilators being shown as
broken away to bring them nearer in the Figure. Each of the ventilators 1 and 2 in
this case has the forced air or gaseous fluid admitted direct at the back end All of
the inner cone nozzle A, A', of the first and second ventilators from the pipes B"
and B² respectively, as indicated by the arrows; the first B" leading the air from
any ordinary blowing fan, or it might be other mechanical or jet blower, so as to
draw the vitiated air and gases from the inlet mouth-piece C", through the annular
neck D and chamber D', and force them out through the discharge pipe E, either
direct through the pipe B2 of the second or next ventilator 2, or, preferably, with
and through the intermediate break or back pressure preventing chamber B¹¹¹, with
a second or supplementary air tube B³ led from this chamber into the outer annular
inlet chamber D of the second ventilator 2, so as to utilize any air and pressure, and
prevent it coming back through the ventilator and its inlet orifice and chainber
C", D, and thus insure the drawing and forcing of the vitiated air from its opening
C" and chamber D, out through its discharge duct E³, either direct by a tube to the
outside of the roof or other part of the house, or otherwise it might be on through
one or more following ventilators in succession, as shown and described in reference
to 1 and 2 of this Figure 9.
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,
First. The general construction or combination and arrangement of the parts of
duplex conical or nozzle ventilators or apparatus and their fittings, all substantially
as herein described in reference to and shown in the accompanying Drawings, or
any mere modification thereof.
Second. The construction of cowls or ventilators with inner and outer conical
cases or tapering contracting nozzles A, A', and C, D, with inlet ducts B, C, and
discharge-inducing tube E for the tops of houses, sewer and soil pipes, and other
places for insuring the ventilation of and from these of bad air and gases, all sub-
stantially as herein described in reference to and shown in the accompanying
Drawings, or any mere modification thereof.
No
In witness whereof, I, the said James Mac Lauchlan Dobson, have hereunto
set my hand and seal, this Twenty-fifth day of December, in the year of our 4
Lord One thousand eight hundred and seventy-eight.
Witness,
W. R. M. THOMSON,
Patent Agent,
Glasgow.
JAMES MAC LAUCHLAN DOBSON. (L.S.)