IMPROVEMENTS IN VENTILATION."
Year: 1855

page_text: LETTERS PATENT to John McKinnell, of Glasgow, in the County of
Lanark, North Britain, Gentleman, for the Invention of "IMPROVEMENTS
IN VENTILATION."
PROVISIONAL SPECIFICATION left by the said John McKinnell at the
Office of the Commissioners of Patents, with his Petition, on the 26th
March 1855.
I, JOHN MCKINNELL, of Glasgow, in the County of Lanark, North Britain,
Gentleman, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN VENTILATION " to be as follows, that is to say:-
This Invention relates to the arrangement and construction of a simple
automatic apparatus to be applied to the upper parts of apartments, the decks
of ships, and in other situations, for the purpose of securing efficient venti-
lation in such enclosed spaces, that is to say, a constant interchange between
the vitiated air of the apartment or enclosed space and the pure air of the
external atmosphere. The apparatus is a tubular structure, consisting essen-
tially of a plain cylindrical pipe of metal or other material, disposed vertically
or otherwise, with its lower end opening through the roof or ceiling of the
apartment directly into such apartment. The upper end of this pipe or tube

page_text: is fitted with any convenient species of open cap for the discharge of the viti-
ated air. The lower portion of the tube is encircled by an external secondary
tube, a considerable annular space being left between the two tubes. This
annular space is open both at top and bottom; the top, which is in the open
air, is covered by an inclined deflecting shield or annular flange, whilst the
bottom, which is coincident or thereabouts with the bottom of the main central
tube and opens into the apartment, is fitted with an adjustable deflecting
flange. This bottom flange is adjustable in such manner that it can either
shut up the bottom of the annular space, or allow any. desired amount of aerial
current down the space, the actual air discharge into the apartment being
deflected laterally and spread well out. The practical effect of this arrange-
ment is, that when fitted. to the ceiling of a room, the main central tube answers
as a direct and clear discharge thoroughfare for the vitiated air, whilst at the
same time a clear inlet supply of pure-atmospheric-air to the apartment takes
place down the annular passage. Thus the reverse currents are shielded from
mutual contact, and the process of ventilation goes on without any extraneous
attention. The top cap of the main tube and the deflecting flange of the
annular passage prevent all down draughts. The apparatus. may be variously
modified so as to carry out this system of double reverse currents, and, various
materials may be used in its construction.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John McKinnell in the Great Seal Patent. Office on the
26th September 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME; I, JOHN
MCKINNELL, of Glasgow, in the County of Lanark, North Britain, Gentleman,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-sixth day of March, in the year of our Lord
One thousand eight hundred and. fifty-five, in the eighteenth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
John McKinnell, Her special license that I, the said John McKinnell, my
executors, administrators, and assigns, or such others as I, the said John
McKinnell, my executors, administrators, or assigns, should at any time agree
with, and no others, from time to time and at all times thereafter during the
term therein expressed, should and lawfully. might make, use, exercise, and

page_text: vend, within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN VENTILATION,"
upon the condition (amongst others) that, I, the said John McKinnell, by an
instrument in writing under my hand and seal, should particularly describe
and ascertain the nature of the said Invention, and in what manner the
same was to be performed, and cause the same to be filed in the Great Seal
Patent Office within six calendar months next and immediately after the
date of the said Letters Patent.
NOW KNOW YE, that I, the said John M Kinnell, do hereby declare the
nature of my said Invention, and in what manner the' saine is to be per-
formed, to be particularly described and ascertained in and by the following
statement in writing, reference being had to the accompanying Drawings, and
to the letters and figures marked thereon, that is to say:-
My said Invention relates to the arrangement and construction of a
simple automatic apparatus to be fixed in the roofs or ceilings of public
halls, churches, dwelling-house apartments, ships' cabins, railway carriages,
and other places, for the purpose of securing efficient ventilation therein,
that is to say, to provide for a steady influx of pure atmospheric air, and
for the discharge of the air which is vitiated by respiration, combustion,
or other causes. The apparatus consists essentially of two tubes, arranged
concentrically, and opening at their lower ends into the space or apartment
to be ventilated. These tubes communicate with the external atmosphere
at different levels, the vitiated air rising up the central tube and passing
off at the higher level, whilst the fresh air enters the annular passage
between the inner and outer tubes at a lower level, and descends into
the space or apartment below. Both passages are provided with suitable
valvular mechanism for regulating the currents, that of the outer passage at
the same time serving to deflect the downward current of fresh air, and spread
it out horizontally, so as to prevent partial draughts.
) And in order that my said Invention may be properly understood, I shall
now proceed to describe the several explanatory Figures on the Sheet of
Drawings hereunto attached.
Figure 1 on the Sheet of Drawings is a vertical section of one modification
of my improved ventilating apparatus, adapted for places where the tubes can
5 be carried vertically upwards through the roof of the structure. Figure 2 is
a plan of the apparatus, as sectioned a little below the hoods surmounting the
tops of the tubes. Figure 3 is a vertical section of the ventilating apparatus
as modified to suit localities where it is necessary to convey the currents along
horizontal passages, as between the floors of a building, for example. In the

page_text: arrangement represented in Figure 1, a tube A, of thin metal or other suitable
material, is fixed in any convenient manner in the ceiling or roof B of the
apartment or space to be ventilated. Inside this tube and concentric with it
is placed a smaller tube C, which is supported by radial ribs D, or in any other
convenient manner. The tube C projects a short distance above the outer
tube A, and is, surmounted by an ornamental cover or hood E, from beneath
the edges of which the vitiated air rising through this central tube escapes,
passing through the perforated screen F, which covers the opening, and pre-
vents the introduction of foreign matters into the tube. The upper open end of
the outer tube A is also covered by an annular hood G, and the entrance space
for the fresh air which passes down the outer tube is likewise defended by a
perforated screen H. The tubes A and C are so proportioned that the sectional
area of the central tube C is about equal to the sectional area of the annular
passage comprehended between the two tubes. When the apparatus is in
action, the doors and windows of the apartment to which it is applied being
closed, the vitiated air which is heated, and consequently lighter than the
external fresh air, rises up the central tube C on account of the greater length
of this tube, whilst the heavier fresh air descends through the shorter external
passage A, and thus a constant current is kept up, the air as it becomes
vitiated and heated rising and passing off, whilst its place is supplied by pure
fresh atmospheric air from the outside of the structure.
The valvular appa-
ratus for regulating the currents consists, in the case of the central tube C, of
a simple throttle valve I, set upon a transverse spindle inside the tube, and
weighted on one side, so as to have a tendency to maintain a vertical position,
leaving the passage full open. The valve is closed wholly or partially by means
of a cord J, conveyed over pulleys K to any point where it can be conveniently
adjusted by an attendant. The valve appertaining to the outer air passage
A is an annular flange or plate L, which slightly overlaps the mouth of the
passage, and is fixed to the bottom of a short length of tube M, fitted to slide
easily inside the tube C. This valve is suspended by means of the bridle
piece N, to which a suspensory cord O is attached, and this cord passes over
pulleys P to any point where it can be conveniently adjusted by an attendant,
a small tube Q being fitted across the tubes C and A to convey the cord to the
outside of these tubes. When the valve L is drawn up as high as is possible,
it completely closes the down draught passage, whilst by letting it down more
or less the passage is correspondingly opened, and the current of air impinging
upon the plate L is deflected and spread out in a horizontal direction, so as to
be more uniformly dispersed over the apartment or space to which the venti-
lator is applied. The under side of the valve L may be ornamented in any

page_text: convenient way, and the central opening communicating with the pipe C may
be covered with a perforated rosette T, to do away with any unsightly appear-
ance, and to render the ventilator an ornament rather than otherwise to the
place to which it is applied. In the modification represented in Figures 3
and 4, the lower portions of the apparatus and the valvular mechanism are
precisely the same as in the modification represented in Figures 1 and 2, and
I have indicated the like details in each Figure by the same letters of reference.
In Figures 3 and 4, however, the tops of the tubes are not represented as
terminated by hoods, but have horizontal tubes joined to them to conduct the
currents in horizontal directions. The top of the tube A is closed, and the
horizontal tube R is joined to it at one side, whilst the tube C has a horizontal
tube S joined to it at a convenient point above the tube A. The tubes R
and S may be continued in any directions to the exterior of the structure to
which the apparatus is applied, it being essential, however, that the tube S
should emerge into the outer atmosphere at a higher level than the tube R.
It is also advantageous to place the mouths of the tubes R and S as far
apart, both horizontally and vertically, as is convenient; and to carry out this
arrangement as much as possible, the tube C may be continued vertically
upwards, as in Figure 1, where it is convenient, whilst the outer air passage A
may be made to communicate with the external atmosphere by a horizontal
tube R, 'as in Figure 3. On my Sheet of Drawings hereunto attached the
ventilating tubes are represented as of circular section, but it is obvious that
the same effect may be obtained by means of tubes of any other convenient
section, such as square or polygonal tubes, the various details being shaped to
correspond.
Having now described and particularly ascertained the nature of my
said Invention, and the manner in which the same is or may be used
or carried into effect, I may observe, in conclusion, that I do not confine or
restrict myself to the precise details or arrangements which I have had
occasion to describe or refer to, as many variations may be made therefrom
without deviating from the principles or main features of my Invention; but
what I consider to be 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 arrangement and construction of apparatus or means for
promoting ventilation, as herein-before described.
Second, the system or mode of ventilating apartments or other enclosed
spaces by means of two concentric tubes or passages opening below in the
ceiling or top of the apartment or enclosed space, and communicating with
the external atmosphere at different levels, as hercin-before described.

page_text: Third, the application and use in ventilating apparatus, in which the inward
current of air descends through an annular passage, of an adjustable flange or
annular plate, which serves to close the passage either, wholly or partially. when.
required, and which when open acts as a deflector to deflect and spread out the
current in a horizontal direction, as herein-before described...
In witness whereof, I, the said John McKinnell, have hereunto set my
hand and seal, this Twenty-fourth day of September, One thousand
eight hundred and fifty-five.