IMPROVEMENTS IN PUNKHA LAMPS FOR BURNING PETROLEUM OILS AND OTHER LIQUID HYDROCARBONS
Year: 1878

page_text: PROVISIONAL SPECIFICATION left by Isaac Blake at the Office of the
Commissioners of Patents on the 18th September 1878.
ISAAC BLAKE, of Birmingham, in the County of Warwick, Commercial Traveller.
"IMPROVEMENTS IN PUNKHA LAMPS FOR BURNING PETROLEUM OILS AND OTHER
LIQUID HYDROCARBONS."
My Invention consists of the improvements herein-after described, whereby the
flickering of the flames produced by strong currents of air is prevented and a perfect
combustion of the said flames is at the same time obtained.
My improvements are specially applicable to lamps used in India and other places
where punkhas are used.
The first part of my Invention relates to the admission of air into the lamp and
the prevention of the said air from impinging on the burner or the flame so as to.
cause it to flicker.
The second part relates to the exit of the heated air in such a way as to prevent
all down, drafts from acting on the burner or the flame so as to cause it to flicker.
My improvements may be used with burners and glass chimneys or without glass
chimneys.
I first select a suitable burner having by preference the perforated part for the
admission of air to the flame above the rack pinion, so as to allow the holder or
gallery for supporting the shade to be above the rack pinion and below the said
perforated part of the burner.
I then make the said shade holder about five inches in diameter, with an upright
rim or flange, into which the rim or flange of the said shade fits. I also make a
hole in the centre of the said holder to fit on the said burner between the perforated
part and the rack pinion. In the shade holder I make a number of small holes
leaving a circular blank space about half an inch broad all round from the edge of
the centre hole.
When the shade holder is fitted on to the burner the circular blank space will be
underneath the perforations in the said burner. I also make a hollow ring cover
having the inside diameter about three inches, and the outside diameter about four

page_text: and a half inches. From the inside edge of the said ring cover the shape rises up in
the form of a segment of a circle to the height of about three-quarters of an inch and
the diameter of about four and a half inches. At the diameter of about four and
a half the said cover may descend perpendicularly for about half an inch. I
then solder the inner flange of the said cover to the blank circle of the said shade
holder, so as to allow the said cover to come over the perforations in the shade
holder; I thus form a chamber, into which the air enters through the perforations
at the bottom.
When the shade is fitted on the said holder and the lamp lighted the air will be
drawn into the said shade through the space between the outer flange of the said
cover and the perforated bottom and the rim or flange of the shade. The said ring
cover may form an integral part of the said burner.
I construct a punkha protecter as follows:-I form of wire gauze or perforated
metal an outside body of a taper or conical shape of about five inches diameter at
bottom, of about three inches diameter at top, and of about three and a half inches
in height.
At the top of the said body I fix a circular sheet of metal having a blank space
of about two inches diameter in the centre, and perforations of half-inch holes
between the blank centre and the outer edge. I also make a metal flue or chimney
about two and a half inches diameter at the bottom, two inches diameter at the top,
and about two inches high.
I fix a flange to the bottom of the said metal flue, and to the bottom of the said
perforated metal body the said flange having suitable perforations between the flue
and the body. At. the top of the perforated metal body I fix a convex cover,
having a hole cut in the centre. To the outer edge of the said convex cover I
fix a band of open work,, ornamental border, or corona, about five inches
diameter.
1
I place or fix a convex metal top about four and a half inches diameter on to the
said corona. The said metal top is perforated near the edge with suitable holes.
For punkha lamps having burners without glass chimneys I make the same
arrangements for the exit of the heated air, except that I make the metal flue or
chimney longer so as to bring it nearer to the flame.