IMPROVEMENTS IN APPARATUS FOR WORKING PUNKAHS.
Year: 1874

page_text: LETTERS PATENT to John Imray, of No. 20, Southampton Buildings, .
Chancery Lane, in the County of Middlesex, for the Invention of
"IMPROVEMENTS IN APPARATUS FOR WORKING PUNKAHS.
PROVISIONAL SPECIFICATION left by the said John Imray at the
Office of the Commissioners of Patents, with his Petition, on the
20th March 1874.
I, JOHN IMRAY, of No. 20, Southampton Buildings, Chancery Lane,
in the County of Middlesex, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN APPARATUS FOR WORKING PUNKAHS," to bo
as follows:-
This Invention relates to apparatus for working punkahs by the agency
of fluid pressure transmitted by pipes from a pumping station, reservoir,
or accumulator, to work pistons which are connected to punkahıs so that
from one central source of power a number of punkahs in separate
apartments may be worked without manual labour. The fluid employed
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page_text: མ་
waཔL སwL F--SS
being obtained either from a natural fall, when such is available, or by
pumping into an elevated. reservoir or a loaded accumulator; or the air
being compressed by means of a pump or pumps worked by steam or
other power.
As punkahs are usually applied in the rooms of barracks, or wards of
hospitals, or other large apartments in India, a number of them are
hung from the ceiling of the apartment and are pulled in one direction
by cords or rods worked by hand, being allowed to swing back in the
other direction by slacking the pulls. The apparatus which I apply is
arranged to operate in this manner so as to serve as a substitute for the
workman usually employed. At or near one end of the apartment I
place a cylinder fitted with a piston, the rod of which is connected
either directly or through a lever to the cord or rope for pulling the
punkahs. By the use of a lever the stroke of the piston can be reduced,
the arms to which the piston rod and punkah pull are connected being
proportioned respectively to the stroke of the piston and the swing of
the punkah. The cylinder may be provided with a slide or cock worked
by tappets from the piston rod or lever arm so as to alternate the supply
of working fluid to the cylinder. I prefer however to arrange the slide
so as to be worked by the fluid itself in the following manner :--On the
side of the cylinder I form a cylindrical slide jacket fitted with a
cylindrical slide in the form of two pistons united by a rod, the one
piston having an area greater than the other. To the smaller part of the
jacket is connected the pipe supplying the fluid under pressure, and
from the larger part of the jacket is led a discharge or escape pipe.
When the slide. is in one position uncovering a supply port to the
cylinder it admits the fluid under pressure to act on the piston, which is
thereby propelled in the one direction, pulling the punkahs. As the
piston approaches the end of its stroke it passes a port by which a
portion of the fluid under pressure is allowed to pass from the cylinder
to the larger part of the slide jacket where it acts on the larger area of
the slide. By this excess of pressure the slide is moved so as to close
the supply port and open a port for discharge from the cylinder. The
piston is then caused to make its back stroke by the back swing of the
punkah until as it approaches the extreme of its back stroke the piston
covers the escape port and by its continued movement tends to compress
the fluid left in the cylinder beyond it. This fluid being in communi-

page_text: cation with the smaller part of the slide jacket is thus made to press on
the smaller area of the slide; and the larger end of the slide being then
in balance as to pressure the slide is thus forced back so as to close the
escape port and to reopen the supply port, whereupon the action of the
piston is repeated.
When compressed air is employed as the working fluid it may escape
into the apartment, but I prefer to connect the escape pipe of the cylinder
to a coil, or to a set of tubes, or other passages presenting extended
surfaces surrounded by water, or to cause the escaping air to bubble
through water in numerous divided streams so that the water is cooled
by the expansion of the air, the water so cooled being available for
drinking, or cooling, or for moistening tattics or other surfaces for the
cooling of the apartments.
Although I have described an arrangement of apparatus for working
several punkahs in a large apartment it may be readily understood that
single punkahs in many separate apartments may thus be worked, each
punkah or set of punkalis being operated on by the piston of a cylinder
connected by a supply pipe with the central source of power..
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Imray in the Great Seal Patent Office on
the 17th September 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
IMRAY, of No. 20, Southampton Buildings, Chancery Lane, in the
County of Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent bearing date the Twentieth day of March, in the year of
our Lord One thousand eight hundred and seventy-four, in the thirty-.
seventh year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said John Imray, Her special license that
I, the said John Imray, my executors, administrators, and assigns, or
such others as. I, the said Jolin Imray, my executors, administrators,
and assigns, should at any time agree with, and no others, from
time to time and at all times thereafter during the term therein

page_text: expressed, should and lawfully might make, use, exercise, and vend,
within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN APPÁrátus
FOR WORKING PUNKAнS," upon the condition (amongst others) that I, the
said John Imray, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and seals, should par-
ticularly 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 Scal 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 Imray, do hereby declare the
nature of the said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement thereof, reference being had to the accompanying
Sheet of Drawings, and to the figures and letters marked thereon, that
is to say :-
This Invention rclates to apparatus for working punkahs by the agency
of fluid pressure transmitted by pipes from a pumping station, reservoir,
or accumulator to work pistons which are connected to punkahs, so that
from one central source of power a number of punkahs in separate
apartments may be worked without manual labour. The fluid employed
may either be water under pressure or compressed air, the water pressure
being obtained either from a natural fall, when such is available, or by
pumping into an elevated reservoir or a loaded accumulator, or the air
being compressed by means of a pump or pumps worked by steam or
other power.
As punkahs are usually applied in the rooms of barracks, or wards of
hospitals, or other large apartments in India a number of them are liung
from the ceiling of the apartment and are pulled in one direction by
cords or rods worked by hand, being allowed to swing back in the other
direction by slacking the pulls. The apparatus which I apply is arranged
to operate in this manner so as to serve as a substitute for the workmen
usually employed. At or near one end of the apartment I place a
cylinder fitted with a piston, the rod of which is connected either
directly or through a lever to the cord or rope for pulling the punkals.
By the use of a lever the stroke of the piston can be reduced, the arms
to which the piston rod and punkah pull are connected being propor-
tioned respectively to the stroke of the piston and the swing of the

page_text: punkah. The cylinder may be provided with a slide or cock worked by
tappets from the piston rod or lever arm so as to alternate the supply of
working fluid to the cylinder. I prefer however to arrange the slide so
as to be worked by the fluid itself in the following manner:- -On tho
side of the cylinder I form a cylindrical slide jacket fitted with a
cylindrical slide in the form of two pistons united by a rod, the one
piston having an area greater than the other. To the smaller part of
the jacket is connected the pipe supplying the fluid under pressure, and
from tlic larger part of the jacket is led a discharge or escape pipe.
When the slide is in one position uncovering a supply port to the
cylinder it admits the fluid under pressure to act on the piston, which is
thereby propelled in the one direction pulling the punkahs. As the
piston approaches the end of its stroke it passes a port by which a portion
of the fluid under pressure is- allowed to pass from the cylinder to the
larger part of the slide jacket, where it acts on the larger area of the
slide. By this excess of pressure the slide is moved so as to close
the supply port and open a port for discharge from the cylinder. The
piston is then caused to make its back stroke by the back swing of the
punkals, until as it approaches the extreme of its back stroke the piston
covers the escape port and by its continued movement tends to compress
the fluid left in the cylinder beyond it. This fluid being in communi.
cation with the smaller part of the slide jacket is thus made to press on
the smaller area of the slide, and the larger end of the slide being then
in balance as to pressure the slide is thus forced back so as to close the
escape port and to reopen the supply port, whereupon the action of the
piston is repeated.
When compressed air is employed as the working fluid it may escapo
into the apartment; but I prefer to connect the escape pipe of the
cylinder to a coil, or to a set of tubes, or other passages presenting
extended surfaces surrounded by water, or to cause the escaping. air to
bubble through water in numerous divided streams so that the water is
cooled by the expansion of the air, the water so cooled being available
for drinking, or cooling, or for moistening tatties or other surfaces for
the cooling of the apartments.
:
Although I have described an arrangement of apparatus for working
several punkahs in a large apartment it may be readily understood that
single punkals in many separate apartments may thus be worked, each

page_text: DESCRIPTION OF THE DRAWINGS.
Fig. 1 represents diagrammatically the longitudinal section of an
apartment with several punkahs P, P, hung from the ceiling and worked
by compressed air acting on a piston in a cylinder C fixed at one end of
the apartment. The piston works a bell-crank lever L, to the lower end
of which, the punkahs are connected by cords or wires. The compressed
air propels the piston upwards, and the punkahs are thus caused to make
their swing in the one direction, and when the piston is relieved of
pressure it descends by its weight and the punkahs swing in the opposite
direction. They may be aided in their back stroke by a spring S, or a
counterbalance weight on a lever, or hung over a pulley.
Fig. 2 represents to an enlarged scale a side view of an arrangement
of the air cylinder and its piston to act on the punkahs through a straight
lever. C is the cylinder projecting horizontally from the wall of the
apartment. On its piston rod R is mounted a roller bearing against the
side of the lever L, the lower end of which is connected to the punkahs.
The alternate admission of the compressed air to the cylinder and its
emission therefrom may be effected by a two-way cock or a slide V
worked by tappets from the lever L, a tumbling weight or spring being
employed to complete each stroke of the cock or slide.
In order to ensure tightness I prefer to employ instead of a cock or
slide a pair of plug valves worked by tappets, as shewn in Figs. 3 and 4,
which represent to an enlarged scale a pair of such valves and means of
working them, Fig. 3 being a longitudinal section and Fig. 4 a sectional
plan of the valve box. a is the pipe supplying the compressed air, fitted
with a plug valve a¹; and 6 is the pipe for the discharge of the air after
it has operated in the cylinder, this pipe being also fitted with a plug
valve ; between these valves is the chamber of the valve box, having
a port c opening into the cylinder; in this chamber is mounted a
spindle d which passes through a cup leather or other packing to the
exterior, and has fixed on it the tumbling arm d¹ worked by tappets.
Within the valve chamber there is fixed on the spindle da cam between
two side checks, projecting respectively from the valves a' and 7. On
each of these cheeks is mounted a roller, the spindle of which passes
5

page_text: through a slotted hole in the other check, and both cheeks have slotted
holes for the spindle d. The arm d¹ is shewn in Figs. 3 and 4 in its
middle position when both the valves a¹, b¹, are closed. When the arm d¹
is made to tumble to the right side the left side of the cam acting on
the roller next it opens the valve a' leaving b' closed, thus admitting air
from a to the cylinder by the port c; when the arm d¹ is made to tumble
to the left side the valve 6' is opened while a' is closed, the air being
thus allowed to escape from the cylinder.
Fig. 5 represents a vertical cylinder fixed against the wall of the
apartment, having its piston arranged to act on the punkahs by a cord.
or strap passed over pullies so as to double the stroke of the piston.
Fig. 6 represents to an enlarged scale a section of the lower part of
the cylinder shewn in Fig. 5, with a slide valve acted on by the air so as
to alternate its admission and emission. This slide consists of two
pistons of unequal size, M and N, united by a stem; the casing has a
port O opening into the bottom of the cylinder, a port P by which the
compressed air is supplied, a port Q opening into the cylinder at Q' some
distance from the lower end, a port R for the discharge of the air, and a
port S communicating by a pipe with an opening into the cylinder at S₁
near its upper end (see Fig. 5). When the slide is in the position shewn
in Fig. 6 the piston descending the air escapes from the cylinder by the
ports Q and R; but when the piston in its continued descent passes the
opening Q the farther escape of air from the cylinder is cut off, and
the air left under the piston becomes compressed. The pressure com-
municated through the port O acts on the piston N and forces the slide
to the right, closing the port Q and opening a communication between
P and O. The compressed air supplied by P and entering the cylinder
by O propels the piston upwards until it passes the opening S¹; the
pressure then communicated through the port Sand acting on the larger
area of M forces the slide back to the left hand, as shewn in Fig. 6,
whereupon the action is repeated. As the swing of the punkahs is effected
only, in the one direction by the pneumatic action they do not unless
provided with a counterweight or spring make a backward swing much
beyond the vertical line from their point of suspension.
'
In order that they may appear to make their full swing backwards
they may be hung, as shewn, diagramatically at Fig. 7 by ties T a little
out of their upright attitude when they are directly under their point of
:

page_text: suspension, so that at each extreme of their stroke they may make nearly
the same angle with a vertical line.
Having thus described the nature of my Invention, and in what
manner the same is to be performed, I claim, the use for working
punkahs of apparatus consisting of cylinders provided with suitable
cocks, slides, or valves, and with pistons connected to the punkahs, the
apparatus being so arranged that compressed air or other fluid under,
pressure transmitted by pipes to the cylinders is made alternately to act
on the pistons so as to pull the punkahs in one direction, and to escape
from the cylinders so as to leave the punkabs free to swing backwards,
substantially as herein described.
In witness whereof, I, the said John Imray, have hereunto set my
In witness whereof, I, the said John Imray, have hereunto set my
hand and seal, this Tenth day of September, in the year of our:
Lord One thousand eight hundred and seventy-four.