Improvements in Air Extractors or Ventilators for Railway and other Carriages and the like.
Year: 1897

page_text: Improvements in Air Extractors or Ventilators for Railway and
other Carriages and the like.
We, FRANK BRACEBRIDGE MILLS, Engineer, of 60, Hatton Garden, E.C., in the
County of London, and WALTER KERR, Engineer, of 7, St. Anne's Terrace,
Harlesden, in the County of Middlesex, do hereby declare the nature of this inven-
tion to be as follows:-
:-
This invention for improvements in air extractors or ventilators for railway and
other carriages and the like has for its object an air extractor that shall draw air
from the space or compartment to which it is connected irrespective of position,
direction of travel and direction of the wind, and shall not project materially from
the outer frame or casing or door of the space or compartment, and shall be steady
notwithstanding gusts or sudden movements and shall not be liable to indrafts;
and a ventilator shutter that shall when open only allow of the extraction of air
more or less in the plane of the shutter and shall be simple in construction; and
consists in a hollow hemispherical or similar concave curved body having a slot or
opening extending partially around its greatest circumference or apex at right
angles to its base, and an exterior guard ring secured to the body and surrounding
the slot at some distance therefrom and projecting beyond the edges of the slot;
and of a tube leading from an air extractor or ventilator and provided with a valve
seating, and a valve or shutter fitting on the said seating and adapted to be held
against the said seating or retained at a small distance therefrom.
In an air extractor constructed according to this invention the base of the air
extractor is placed on a side of the compartment or on the door and the interior
of the body of the ventilator communicates by an opening or pipe with the interior
of the compartment. The whole apparatus can be cast in one piece.
The edge of the slot may project slightly towards the guard ring and a channel
may be formed below the slot within the ventilator to catch rain or other water.
The opening leading to the compartment may be provided with a valve closing
automatically when the vehicle is not in motion and the wind is slight and also
when the outflow is excessive, or the opening may be covered with gauze.
When an air extractor is provided with a ventilator shutter constructed accord-
ing to this invention the pipe from the extractor leads preferably through the roof
of the compartment and just inside the roof is provided with a horizontal seating.
The valve or shutter adapted to fit on the seating is provided with a central stem
guided in a boss supported in the centre of the pipe by ribs or wings. Within a
slot in the stem is a U spring having projecting knobs adapted to take into cir-
cumferential grooves in the bore of the central boss when the disc is pulled down-
wards or pressed upwards and hold it in the lower or upper position as the case
may be.
The air from the compartment can freely enter the pipe in a horizontal direction
between the upper surface of the valve or shutter and the seating and consequently

page_text: the top strata of air are extracted from the compartment and the air current
diffused, whereby direct drafts are more or less prevented.
Dated this 10th day of June 1897.
WHEATLEY & MACKENZIE,
40, Chancery Lane, London, W.C., Agents.
improvements in Air Extractors or Ventilators for Railway and
other Carriages and the like.
We, FRANK BRACEBRIDGE MILLS, Engineer, of 60, Hatton Garden, E.C., in the
County of London, and WALTER KERR, Engineer, of 7, St. Anne's Terrace
Harlesden, in the County of Middlesex, do hereby declare the nature of this inven-
tion, and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement:-
-
This invention for improvements in air extractors or ventilators for railway and
other carriages and the like has for its object a ventilator shutter that shall when
open only allow of the extraction of air more or less in the plane of the shutter
and shall be simple in construction; and consists of a tube leading from an air
extractor or ventilator and provided with a valve seating, and a valve or shutter
fitting on the said seating and adapted to be held against the said seating or
retained at a small distance therefrom.
In an air extractor provided with a ventilator shutter constructed according to
this invention the pipe from the extractor leads preferably through the roof of the
compartment and just inside the roof is provided with a horizontal seating. The
valve or shutter adapted to fit on the seating is provided with a central stem guided
in a boss supported in the centre of the pipe by ribs or wings. Within a slot in
the stem is a spring having projecting knobs adapted to take into circumferential
grooves in the bore of the central boss when the disc is pulled downwards or pressed
upwards and hold it in the lower or upper position as the case may be.
The air from the compartment can freely enter the pipe in a horizontal direction
between the upper surface of the valve or shutter and the seating and consequently
the top strata of air are extracted from the compartment and the air current diffused
whereby direct draughts are more or less prevented.
In the accompanying sheet of illustrated drawings:-Figs. 1 and 2 are central
vertical sections at right angles to one another showing the ventilator shutter
closed, and open respectively.
As shown the ventilator shutter is shown applied to our patent ventilator or air
extractor No. 6918 of 1897 but it may be applied to any other suitable form of
ventilator.
The air extractor or ventilator proper A is fitted to the roof a
part of the compartment to be ventilated.
or other convenient
3
40
Screwed to the under side of the roof of the compartment is an annular casting b
having a seating c and provided with a central tubular boss d carried by three arms
or wings e. A shutter f preferably dished as shown and adapted to rest against
the seating c when the ventilator is closed, is provided with a central stem or
spindle g guided by and working freely within the boss d, the downward movement 45
being limited by the head has shown.
Carried within a slot opening in the spindle g is a spring i held freely by the
pinj so that its ends k k¹ are free to open out or close together as the shutter f is
pressed up or drawn down by means of the knob or handle 7.

page_text: When the shutter and its spindle are pressed upwards the ends of the spring
open out drawing the spindle upwards and by pressing on the top edge of the
central boss firmly hold the shutter against its seating (Fig. 1).
When the shutter is drawn down the ends of the spring close in and bear against
the inner surface of the hollow boss as shown in Fig. 2.
In a modification of the shutter the head h of the central spindle g is increased
in diameter so as to overlap the boss d and engage a helical compression spring
arranged around the boss and resting on the arms e and which tends always to lift
the spindle and shutter and thus to close the ventilator.
To provide that the ventilator shall when desired remain open, the ends of the
spring i are provided with knobs or enlargements adapted to enter a circumferential
groove or recess in the boss of the central boss and to thus lock the spindle and
shutter in the open position until released by a slight upward pressure on the
handle 1. If desired two or more grooves may be formed in the boss to enable
the shutter to be locked in intermediate positions i.e. partially open or closed.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim is:-
1. The improved ventilator shutter or valve adapted to be held against its seat-
ing or fully open substantially as described.
2. The improved ventilator shutter or valve substantially as described with
reference to the drawings.
Doted this 5th day of April 1898.
WHEATLEY & MACKENZIE,
40, Chancery Lane, London, W.C., Agents.