Central Draught Ejector or Injector Ventilators.
Year: 1892

page_text: Date of Application, 14th May, 1892
Complete Specification Left, 14th Feb., 1893-Accepted, 18th Mar., 1893
PROVISIONAL SPECIFICATION.
Central Draught Ejector or Injector Ventilators.
We, JOHN DUNCAN GRAY THOMPSON of 165 Queen Victoria Street in the
City of London and ROBERT POLLOCK of 136 St. Paul's Road, London, N.W.
in the County of Middlesex, Engineers, do hereby declare the nature of this
invention to be as follows:-
This invention relates to exhaust and downcast ventilators wherein the air is
first conveyed upwards through tubes and then inwards towards the centre and
downwards through the centre, and expelled through spaces between the tubes
that convey the air upwards or the air passes in the spaces between the tubes and
is conveyed upwards in the centre, and outwards, and down through the tubes as
the case may be.
They are impervious to rain snow or sleet, all vibrating and whistling sounds
are overcome, and they can be made to harmonize with any building better than
those hitherto sold, and are powerful inducers or conductors of air and wind
currents. The difference of temperature in the inside and outside will also be an
inducing agent in these ventilators.
A base or air chamber is constructed of a circular, square, octagon, hexagon, or
any other shape. Round this base or air chamber on the upper side and penetrating
the same are set hollow tubes or pillars which may consist of any number. These
tubes may be round, square, oval, diamond, hexagon, octagon, triangular, or any
other shape. These tubes or pillars will be placed on the base or air chamber at
equal or unequal distances apart, having a space between the tubes in the centre
measuring across the diameter, and will be the means of conveying the air between
the base or air chamber to another air chamber constructed at the upper end of
the tubes, the ends of the tubes penetrating the bottom of the upper air chamber.
An opening is made in the bottom of the upper air chamber in the centre
between the tubes so that when the wind blows through the spaces or openings
between the tubes the air is exhausted through the centre opening or openings in
the bottom of the upper air chamber, being first conveyed upwards through the
tubes then downwards through the centre opening between the tubes or pillars.
We may also cause to be inserted between the top and bottom air chamber, auxiliary
air chambers which may consist of any number.
These auxiliary air chambers shall also have outlets in the centre between the
tubes or pillars and will be connected with the tubes or pillars, or with the upper
or lower air chambers. We may also construct horizontal tubes which may be
any shape, and they may pass round the outside of the ascending tubes or pillars,
or they may be inside, or the ascending tubes may pass through them, or they may
pass through the ascending tubes or pillars or have connection with them at either
side. Openings may be made in the horizontal tubes in the bottom or inside
toward the centre.
Horizontal tubes may also be taken through the ascending tubes or pillars of a
smaller size than the tube or pillar having openings in their top or upper side.
Horizontal tubes may also be fixed with their ends between the spaces or openings
of the ascending tubes or pillars and an opening or openings made in the top of
these horizontal tubes with an air chamber embracing or covering these openings,
and be connected with the lower or upper air chambers. Horizontal tubes may
also be taken through the upper and lower air chambers having openings in the tops
of said tubes so that the air may pass down through these openings and be expelled
through the horizontal tubes. We may, under certain conditions fix the ascending
tubes or pillars at an angle, or they may cross each other, forming a triangle or

page_text: other shape, or they may be connected with the upper air chamber on the opposite
side from which they join the lower air chamber. We may also place inverted
cones with their small end looking downwards to guard the wind, away from the
opening or openings in the central outlets; whether horizontal or vertical. We
may find it convenient at times to make the outlet openings in the central sides of
the horizontal or vertical tubes or air chambers. We may also take a single
horizontal or vertical tube and make an opening in the top or sides and embrace
this opening with an air chamber having the inlet opening in the 'bottom or lower
side of the air chamber so that the air enters the opening in the botton or
lower side of the air chamber and is expelled through the top or side openings
in the horizontal or vertical tube as the case may be; said horizontal or vertical
tubes may consist of any number passing through an air chamber or air chambers,
and may be set side by side, or they may cross each other, or be set in a
diagonal, triangular, or any other form. We may use an injector or injectors
which will be in the form of a tube or tubes 'taken in at the top or sides of the
upper air chamber and taken to the central opening in the bottom of the upper
air chamber, where it will blow downwards through this opening to create a
vacuum behind it. This injector or injectors may also be fixed in the horizontal
or ascending tubes or pillars, or in the auxiliary air chambers. We may connect
a tube or tubes to the central opening or openings in the bottom of the upper
air chamber hanging downwards so that the air may pass down these tubes or
their lower ends may be connected with the top of the horizontal tubes or rings
of tubes, or small air chamber or horizontal tubes may pass through them also
having the openings in the bottom or sides in a central position so that the air
may be exhausted downwards or inwards through the central openings.
When we use these ventilators as downcasts we may place in the centre
under the central opening or openings of the upper air chamber, inverted cones,
plates, or guards, to prevent the wind blowing straight through, and to shoot
it upwards into the top air chamber when it will pass down the tubes or pillars
to the lower air chamber, thence to the places where the air is desired, or we may
use a movable hood to turn with the wind in the centre and shoot the air upwards
into the upper air chamber. We may also use valves in these ventilators both
downcast and exhaust to open and close with the pressure of the wind.
at times use in the centre outlet or other portion of these ventilators, nozzles or
fans, worked by water, steam, compressed air, or other inducing agent.
We may
The same principle will always be maintained in whatever form these ventilators
may take.
Exhausting first upwards through the tubes or air chambers and then down-
wards or sideways in a central position, or injecting upwards in a central position,
and then downwards through the tubes or air chambers.
Dated this 14th day of May 1892
S. S. BROMHEAD,
.97, Newgate Street, London, E.C., Agent for Applicants.
COMPLETE SPECIFICATION.
Central Draught Ejector or Injector Ventilators.
We, JOHN DUNCAN GRAY THOMPSON of 165 Queen Victoria Street, in the
City of London, and ROBERT POLLOCK of 136 St. Paul's Road London, N.W.
in the County of Middlesex, Engineers, do hereby declare the nature of this
invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
This invention relates to a method of ventilation, applicable to both exhaust
and downcast ventilators, wherein the air is first conveyed upwards through iubes
and then inwards towards the centre of the ventilator, and theu downwards through
the centre, and is then either expelled through the open spaces between the tubes
'

page_text: that convey the air upwards; or conversely, the air passes into the spaces between
the tubes, and ascends upwards in the centre, and then passes outwards and down
through the tubes, as the case may be.
Our improved ventilators are impervious to rain, snow or sleet; they are
noiseless, all vibrating and whistling sounds being overcome; they are powerful
inducers or conductors of air and wind currents, and they can be made to harmonize
with the design of any building better than those ordinarily employed. The
difference of temperature in the inside and outside, will be an active inducing
agent in these ventilators.
A base or lower chamber is constructed of a circular, square, octagon, hexagon
or any other suitable shape. Rising vertically or otherwise from this base, and set
on the upper side thereof, and penetrating into the same, are tubes or hollow pillars
of any preferred number. These tubes are preferably of ornamental appearance,
and may be of any pattern in section such as round, square, oval or diamond,
hexagon, octagon, triangular or otherwise. These tubes or pillars will be placed on
the base or lower air chamber at equal or unequal distances apart from each other,
and having an open space between them in the centre, measuring across the diameter
of the base. The tubes form the means of conveying the air from the lower air
chamber to an upper air chamber, or the reverse, such upper chamber being
constructed at the upper end of the said tubes and communicating therewith.
In the lower side of the upper air chamber an opening, or openings are formed,
the effect of which is that when used as an exhaust ventilator, the wind blowing
through the open space or spaces between the tubes, exhausts the air in the upper
air chamber, through the opening or openings in the lower side thereof, by suction
or syphonage, whereby air is caused to ascend upwards through the tubes from the
lower air chamber, and then to pass downwards through the centre opening between
the tubes or pillars. We may also cause to be inserted between the upper and
lower air chambers one or more auxiliary air chambers, with outlets in the centre
space between the pillars.
These auxiliary air chambers may be connected with the pillars, or with the air
chambers, or with both.
Tubes or cones either borizontal, ascending or descending, may be added as
hereafter described, also valves, nozzles, or fans worked by water, steam, or com-
pressed air, or by other means.
When used as downcast ventilators, plates or guards may be introduced to form a
shield or hood to collect the wind.
We will now describe the invention with reference to the accompanying drawings
in which,
Fig. 1 shows a sectional elevation of an ejector ventilator, in which the foul air
passes upwards into the tubes a, then inwards towards the centre of the upper
air chamber d, and escapes downwards through the central aperture, and is expelled
through the spaces between the tubes, as shewn, by the direction of the arrows.
c, is a cone which may be attached to the base to facilitate the dividing of the
air to enter the various tubes. d, is the upper air chamber through which the foul
air passes on its way out. It may be of any shape or dimensions. d, is the lower air
chamber through which the air passes before entering the tubes.
Fig. 2 shows an elevation of the ventilator shewn in Fig. 1 when completed.
Fig. 3 shows a sectional plan of such a ventilator as that shewn in Figs. 1 and 2
at the line 1-2 on Fig. 2.
Fig. 4 shows in section, various shapes in which, or in any other shape, the tubes a,
could be formed.
Fig. 5 shows longitudinal elevations of other forms of tubes and jackets in which
a, could be formed.
Fig. 6 shows a ventilator having various auxiliary chambers to induce draught,
but it should be understood that all the methods here shewn would not be simul-
taneously employed on a ventilator. e, shows a circular auxiliary chamber connected
to the tubes a. When the wind passes between the tubes it draws the air out of

page_text: this chamber e, and consequently from the tubes a, through an orifice or mouth
below the chamber. e', shows a similar chamber surrounding and connected with
the tubes a, working in the same manner as e. d², and d³, represent tubes each
connected by an opening with a chamber through which the bad air passes. The
wind blows down these tubes and the bad air is drawn out and carried away.
Fig. 7 shows a sectional elevation of another ejector ventilator. f, is a base which
can be applied to make the ventilator sit more securely on the roof. a', are tubes
passing through and connected with the tube a, and performing the same functions
as d², d, in Fig. 6. a² is another contrivance to assist the rapidity of the ejection
of the bad air by means of the penetration of the external air up the tube a. One
or more of these can be fixed to each of the tubes a. At the upper air chamber d,
is seen another contrivance to induce draught, consisting of a divided injector
tube 9. The wind passes in at the mouths of these tubes and out again at the upper
chamber outlet. The bad air is by this means drawn out, the wind passing swiftly
out of the upper chamber outlet would form a vacuum. Said vacuum being supplied
with bad air from the chamber d' through the tubes a.
The dotted lines represent the position in which plates or inverted cones could
be placed to prevent the wind blowing into the upper chamber d.
Fig. 8 shows a sectional elevation of an ejector ventilator having an arrangement
of interpenetrating tubes which could be used if desired instead of any of the forms
of tubes a, heretofore shewn.
Fig. 9 shows a sectional elevation of an ejector ventilator having various con-
trivances for extracting vitiated air and promoting quicker draught, all of which in
practice would not be used on the same ejector. It will be understood that the
upper chamber d, has a lip g', which may be employed if desired to better protect
this chamber from the back draught of the wind. Three rings of auxiliary tubes
connected by outlets to the vertical descending tubes a, and also by outlets to the
outside air are shewn. One ring surrounds the tubes a, another ring passes through
the tubes a, and the third ring connects the tubes a together, at their parts nearest
the centre; the wind passing between the tubes a, draws the vitiated air which is
passing up the vertical ascending tubes a, into these rings and thence into the air to
be carried away. g, is a head of circular or other desired form connected to the
lower air chamber d, having horizontal auxiliary tubes g', passing through it.
g, may as shewn pass through the vertical ascending tubes a, or not, as desired.
The auxiliary tubes g³, have an outlet g*, connecting them with the head, so
that when the wind passes along these tubes g³, the foul air is drawn out of g³,
where it had arrived from the chamber d', and passed into the outside air. 0, 0, are
bosses which may be connected with the vertical ascending tubes a, as shewn by
removing part of the tubes a, or by forming holes of connection. o¹, o' are plates
placed in front of the outlets of these bosses to the external air, to prevent the
wind blowing in. They act in the same way as the auxiliary rings above
mentioned.
Passing through the upper air chamber d, is seen a divided injector tube g,
similar to that shewn in Fig. 7, for creating a draught at the upper chamber
outlet.
Fig. 10 shows another form of our ejector ventilator in which we employ a wheel
or wheels h, h' turned by the wind or any other niotor connected with and turning
a fan, in the upper chamber outlet for the quick ejection of the vitiated air,
3, 3, are supports for the spindle on which the wheels and fan are fixed.
Fig. 11 shows a form in which we have a nozzle i, protruding out of the upper
chamber, through which we can pass steam, water or anything suitable to create the
air draught desired.
Fig. 12 shows a sectional end elevation, Fig. 13 a plan, and Fig. 14 a side
elevation, of an ejector ventilator in which a cylinder j, penetrates a circular or
other shap d ring j, connected with the room or other place desired to be
ventilated.
This is on the same principle as that shewn in the auxiliary outlets at a¹, Fig. 7.

page_text: , is the opening out of which the foul air is drawn by the draught of the wind.
, is an auxiliary tube passing down the cylinder and connected to j, by an
outlet.
Figs. 15 and 16 shows a sectional plan and sectional elevation respectively, of an
ejector, with an upper and lower air chamber similar to that shewn in Figs. 12, 13,
and 14, only cylinders, crossing each other are employed, instead of the single
cylinder. 2, is the opening out of which the bad air is ejected.
1, shows forms of auxiliary outlets in which the wind passes round a part, which
is connected with the upper air chamber d by a cylinder 12, and has an outlet 1³, out
of which the vitiated air is drawn by the wind.
Fig. 17 is a similar ejector ventilator to that shewn in Figs. 12, 13 and 14 for
fixing inside a roof with the exception that the cylinder j', is shewn with sloping
ends and with sloping boards at one end for carrying off rain.
Covering the bad air outlet is shewn an arrangement of valves m, which may be
arranged V shaped or vertically as shewn in dotted lines or in any other suitable
manner. When the wind blows from left to right the valves m', on the left side
would be shut and the valves m², open, and conversely. Out of the valves m², the
bad air would then be drawn.
At the other end could be placed a wire netting or grating to prevent leaves or
anything entering.
Both ends could be covered with a grating, and having sloping boards or otherwise
as desired.
Fig. 18 is a similar ejector ventilator arrangement, without the valves, and at one
or both ends may be placed down-flaps n', for deflecting the wind under a plate n,
out of which the air would be drawn from the outlet over it.
The dotted lines shew other forms of plates which could be employed if
desired.
Fig. 19 shows a sectional elevation of an ejector having tubes q, passing through
a chamber p, which is fixed at its base to the roof.
These tubes g, are connected by outlets q' to the chamber p, and the wind passing
through the tubes draws the bad air out of the outlets.
If desired tubes could also cross from the opposite direction to effect the same
purpose when the wind is blowing in an opposite direction.
Fig. 20 shows a plan of Fig. 19, not in section.
Fig. 21 shows a sectional elevation of an ejector with an outlet, out of which the
bad air passes from the upper chamber d, into a chamber r, through which the wind
passes and draws it out.
Fig. 22 is a plan view of Fig. 21, not in section.
Fig. 23 shews, in sectional elevation, an ejector in which the valve arrangement m
has holes for valves and not flaps as shewn in Fig. 17. These holes are protected
by projections and plates m³ and m', placed in suitable positions to prevent the wind
blowing directly into the valve holes and deflect it to pass by them and draw out the
air. On the other side at m³, is shewn another arrangement for obtaining the same
result, the valve hole being placed a little lower down so as to be out of the direct
current of the wind. The dotted arrows here show the direction the wind would
take in blowing from right to left.
Fig. 24 shows, in elevation, a form of ejector, similar to that shewn in
Figs. 12, 13, and 14, doubled, and also with a third connection ³ for exhausting the
vitiated air.
Fig. 25 is a plan of Fig. 24 shewing the position of the various parts, which are
shewn in elevation in Fig. 24.
Fig. 26 shows a sectional elevation of an injector in which a guide, guard or
segmental plate u, fixed to a spindle, turns and always faces the wind which drives
up it through an inlet into an upper chamber t, from whence it passes down the
descending vertical tubes s, into a lower chamber t', from whence it passes into the
room below.

page_text: Fig. 27 shows a plan view of Fig. 26 with the upper chamber t, and the weather
vane removed to show the positions of the various parts.
Fig. 28 shows a sectional elevation of an injector with sloping plates v. for
deflecting the wind upwards through an inlet into the upper chamber t, and
outwards down the descending vertical tubes s. An arrangement of valves a¹, is
shewn between each tube for preventing any syphon action. When the wind
blows from right to left the valves on the right would be open and those on the
left shut and vice versa.
Netting or gratings may be placed before these valves to prevent foreign matter
from entering.
In the upper air chamber t, valves t2, are also shewn. These valves are for the
prevention of back draught.
Fig. 29 shows a plan view of Fig. 28 with the upper chamber t, removed to
show the positions of the various parts. *,, are the descending vertical tubes,
v, v, the sloping plates, and , the arrangements of valves.
Fig. 30 shows a sectional side elevation of an injector of similar construction to
the ejector shewn in Figs. 12. 13 and 14, only one end of the cylinder j', here
denoted by w, is blocked off in this fig. w, is the outer ring surrounding the
blocked off tube . 2, is a funnel or spout for deflecting the wind into the
tube w, from whence it proceeds downwards through the ring wol, into the room
below.
Figs. 31 and 32 show a front elevation and plan respectively of Fig. 30, not in
section. This kind of injector would readily be used for ships and could be made
with movable hood to swing round so as always to face the wind or vice versa.
Holes or openings such as that shewn at w', in Fig. 30 can be made if desired in
any of the ejectors or injectors to allow any water which may be carried in by the
wind to run out.
From the foregoing description of the drawings it will be seen that we employ
when necessary auxiliary air chambers as shewn in Figs. 6, and 16, also supple-
mentary horizontal tubes of any suitable shape, specimens of which are shewn in
Figs. 6, 7, 9, 12, 19 and 20. These tubes may have suitable openings in con-
venient places, and may be fixed in any desired position, and may be connected
with either or both air chambers, or fixed therein if preferred.
We also employ in some cases cones, or inverted cones as shewn in Fig. 1 or
otherwise.
We may also in some cases vary the position of the outlets, and may for instance
make an outlet in one of the horizontal or vertical tubes, and embrace this outlet
with an air chamber as shewn in Figs. 6 and 9.
We may insert tubes in the upper air chamber which shall converge on the
opening in the lower side thereof so as to form injector tubes by the wind blowing
downwards through the opening and creating a vacuum behind it, as shewn in
Figs. 7 and 9, at g. These tubes may also be placed in the ascending tubes as
shewn at «, in Fig. 7, or in the auxiliary air chambers, or may be adapted to serve
as ejectors, or modified in many ways.
When we use these ventilators as injectors or downcasts, we may add a guard, or
guards u, as shewn in Figs. 26 and 27 or inverted cones or plates », as shewn in
Figs. 28 and 29 or otherwise. These have for object to guide or direct the wind
upwards into the upper air-chamber.
We may also use valves in these ventilators both exhaust or downcast, to open
and close with the pressure of the wind as shewn in Figs. 17, 28 and 29.
We may also employ in the centre outlet or elsewhere nozzles or fans as shewn
in Eigs. 10 & 11 worked by water, steam, compressed air, or other inducing agent.
In all the foregoing particulars it should be understood that although admitting
of much variation in detail, and of additions and modifications to suit special
circumstances or purposes, the fundamental principle of these ventilators is the
same in all cases; namely, that when employed as exhaust ventilators, they draw

page_text: the current of air first upwards, vertically or nearly so, through the air-chambers
and tubes, and then laterally, horizontally or nearly so, and downwards through a
central or other aperture, into a central space, between the vertical tubes whence it
is dispersed by external wind currents.
Conversely, when employed as downcast ventilators they inject fresh air, first
upwards, through a central aperture into an upper air-chamber, and then laterally
to the orifices of the vertical tubes, and then downwards through the tubes and
lower air-chamber and thence into the building to be ventilated.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
1. The special form of ventilator herein described applicable both as an exhaust
and downcast ventilator, and consisting of upper and lower air-chambers connected
by vertical or other tubes, the upper air-chambers having central or nearly central
apertures on their lower surfaces, such apertures opening into central spaces
surrounded or partly surrounded by the said vertical tubes, as herein described
and set forth.
2. The special forms of ventilators with horizontal tube or tubes passing
through or embraced by an air chamber or chambers as described in Figs. 12, 13,
14, 15, 16, 17, 18, 23, 19, 20, 21, 22, 24 and 25 as herein described and set forth.
3. The combination of the ventilators described in Claims 1 and 2 with supple-
mentary or auxiliary tubes, cones, injectors, air-chambers, plates, guards, guides,
movable hoods, valves, nozzles, fans and the like, or with any of them; and with
or without some inducing agent, such as water, steam, or compressed air as herein
described and set forth.
Dated this 14th day of February 1893.
S. S. BROMHEAD,
97, Newgate Street, London, E.C., Patent Agent.