IMPROVEMENTS IN VENTILATING APPARATUS
Year: 1880

page_text: PROVISIONAL SPECIFICATION left by Alexander Melville Clark at the
Office of the Commissioners of Patents on the 23rd September 1880.
A communication from abroad by David Groesbeck, of the City, County, and
State of New York, United States of America, Gentleman.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of
Middlesex, Patent Agent. "IMPROVEMENTS IN VENTILATING APPARATUS."
[A communication from abroad by David Groesbeck, of the City, County, and
State of New York, United States of America, Gentleman.]
This Invention relates to apparatus for ventilating all kinds of apartments
whether in buildings, railway carriages, or ships. For railway carriages or cars of
the American type, it has however very marked advantages, and as a description
of it in its application to this branch of ventilation will fully illustrate all its main
features, I will principally confine myself to such a description.
The objects sought and advantages secured by these improvements. are, the
ample supply to confined spaces of fresh pure air; the diffusion of the inflowing
volume of air in such manner as to avoid sharp drafts or currents; the perfect
removal from the inflowing air of all mechanically suspended impurities or dust;
the perfect adjustability of the apparatus to supply more or less air according to all
requirements between a determinate maximum and minimum supply; the exclusion
of snow or rain without interrupting the free influx of air; the exclusion to a great
extent of the deafening noise of railway trains which, finding access through
ventilating openings, is with many kinds of apparatus a serious annoyance, and at
the same to provide an apparatus which, on account of its cheapness and
effectiveness, is capable of a very wide application to ventilating purposes.
The general principle of circulation adopted in this improved apparatus is the
exhaustion from the enclosed space to be ventilated of the foul air contained
therein, and the inflow caused by external atmospheric pressure of pure air to take
the place of the air so drawn out from said enclosed space. The nature of this
Invention, which is devised to carry out this principle in the best possible manner,
consists in adjustable devices, which placed in certain positions relative to the space
to be ventilated exhaust through the action of external winds or currents the
aforesaid foul air, and cause air to be forced in by external atmospheric pressure
diffused and freed from mechanical impurities.

page_text: The apparatus comprises a passage open at both ends through which flows a
current of air exterior to the carriage, which current I shall hereinafter name the
inducing current. Said passage has preferably a greater extent longitudinally
than laterally in relation to the carriage, but the capacity for ventilation possessed
by the apparatus will, with any given adjustment made as hereinafter set forth,
depend upon the lateral measurement of said passage and the speed of the carriage.
Midwise in the longitudinal extension of said passage is placed an adjustable and
reversible deflector in the form of a flat plate having pivots that slide in vertical
guide ways at opposite sides. of the passage. This passage is formed with a
rectangular opening in its upper enclosing wall, and upon one or the other edge of
this opening, toward one or the other end of the carriage, the unpivoted edge of the
deflector rests when the apparatus is adjusted for operation. Above the passage and
communicating freely with it through the said opening is a chamber or enclosed space,
into which flues or passages lend from registers placed in the floor of the carriago, and
the course of the foul air in passing from the interior of the carriage is through
said flues into the chamber, and thence out of one end or the other of the passage
according to the adjustment of the deflector and the direction of the external
current relatively to the carriage. The angular position of the deflector relative to
the direction of the inducing current through the passage may be variously
adjusted, and I do not confine myself to the method which I will now describe.
-To-one-or-both pivots of the. deflector is connected a rod which is pivoted
to a lever provided with means to fasten it in any desired position. By means
of this lever a person within the carriage may adjust and fasten the deflector
at any angle desired. Such adjustment regulates the-flow-of-air-out-of-the-carriago-
-as-will-be-described-further-on.-The Blues_or_passages are_for_railway carriage
ventilation preferably arranged to take their air from the middle part of the carriage,
in order that the flow of air in the carriago may be from the ends towards the
middle. As stoves in railway cars or carriages of the American type are generally
placed at the ends of the carriage, the arrangement described causes a more uniforin
distribution of the heated air along and over the floor of the carriage, thus adding
greatly to the comfort of passengers.
The operation of the parts of the Invention thus far described is as follows:- The
deflector when raised to a horizontal position continuous with the top of the passage
has no action, but when inclined in such manner that its pivoted edge is in the
least lower than the top of said chamber, it will when the exterior air current flows
through said passage in such manner as to impinge against the underside of said
deflector, deflect downward the current which passes under its pivoted edge; such
current then becomes an inducing current, that is to say, it produces a reduction of
pressure in the chamber above said passage by continuously exhausting air
therefrom, and to fill the partial vacuum thus produced, air rushes from the carriage
through the pipes or flues into said chamber, from which it in turn is drawn out
and discharged with the inducing current; air to supply the place of that thus
taken from the inside of the carriage is admitted through diffusers, hereinafter
described. That the effect described above may be produced, no matter which end
of the carriage is in the advance when the carriage is in motion, it is necessary
either to have two contrariwise arranged apparatus (which is objectionable, not
only on the score of increased cost, but also because the inoperative one would
admit snow, rain, and dust), or to render the deflector reversible. This I accomplish
in the following manner, but I do not strictly limit myself to this method, as other
methods may be employed :-
To the unpivoted edge of said deflector I attach cords which pass in opposite
directions over separate pulleys, the free ends of the cords passing downward through
sleeves into the interior of the carriage. Pulling one or other of these cords
downward at once reverses the position of the deflector, and the angle of inclination
of said deflector after the same has been reversed 'will be the same for any
adjustment of its pivots as before the reversal but in an opposite direction.

page_text: I find the apparatus hereinbefore described works better with side openings, one
placed in each side of the passage opposite each other below said deflector, and
mid wise in said passage; these permit the surplus air which enters the passage to
find ready egress from said passage.
At some other part of the carriage or other enclosed space to be ventilated,
dependent upon circumstances, I provide an apparatus for admitting, purifying, and
diffusing the air necessary to replace the air exhausted from said carriage or other
enclosed space. This apparatus consists in an air chamber having openings, which
freely admit external air, and a peculiarly constructed slide which forms the cover
of said chamber, and which slides in and out in ways or grooves provided for its
edges and formed on the inside of said chamber. The construction of said slide is
as follows-First, a frame is made, preferably of rectangular form, to both sides of
which is fastened a diaphragm of perforated or reticulated material, preferably
wire cloth; between these diaphragms is placed a uniform filling of sponge torn or
cut into pieces sufficiently small to allow of its even distribution throughout the
space between the diaphragms.
For railway carriages I prefer to place a diffuser at or near each end of the
carriage, and in the upper part of the carriage near the roof thereof; the action
of these diffusers is, whilo admitting ample volume of air from the exterior of the
carriage into the interior of the same, to filter out from the inflowing air all
mechanical impurities, whether it be dust, drifting snow, or any other substance
floating in and carried along by the current, and to so subdivide and diffuse the
current and distribute it over a large area as to reduce its velocity below that
which renders currents of air sensible to the human skin, thus entirely obviating
injurious or annoying drafts.
The position of the apparatus for generating the inducing current is at the top
of the carriage, which arrangement in great measure excludes the noise produced
by the train.
By the arrangement of a slide carrying sponge between perforated or reticulated
diaphragms, I supply a convenient means for cleansing the diffuser. The slide is
drawn out of its grooves, beaten or washed, as may be needed, or both, and then
replaced.
'
The combination of the diffusing slide with the air chamber, into which the air
flows before passing through the diaphragms and sponge, causes the air to pass
into the car at a low velocity and in large volume instead of in sharp piercing
currents.