Improvements in Wickless Oil Lamps or Night Lights.
Year: 1896

page_text: Date of Application, 19th Mar., 1896
Complete Specification Left, 16th Dec., 1896-Accepted, 27th Feb., 1897
Improvements in Wickless Oil Lamps or Night Lights.
I, JOHN FREDERICK DUKE of 160 Rosendale Road, West Dulwich in the
County of Surrey, Chemist, do hereby declare the nature of this invention to be as
follows:-
My invention has reference to wickless oil lamps or night lights of the kind
which comprise a dish or cup with a small central vertical tube passing through it
and open at both ends. This dish or cup is of such buoyancy that it floats upon
the oil in an open reservoir, being however submerged just sufficiently to bring the
upper end of the tube down to a proper level relatively to the level of the oil.
The tube constitutes a wickless burner. These lamps have this serious objection :-
As the oil becomes slightly warmed its specific gravity decreases while that of the
dish remains the same. The dish consequently becomes slightly more submerged
so that the oil level in the tube correspondingly rises. The flame then increases,
and further warms the oil, until, by further slight submergence and further increase
of flame smoke is given off.
Now the object of this invention is to so construct the lamp that the buoyancy
of the dish will increase as the specific gravity of the oil diminishes owing to the
heat whereby the oil level in the tube is maintained at a constant level. For this
purpose I form one or more cavities or recesses in the under side of the dish so
that when the dish is placed upon the oil air becomes enclosed in the cavity or
cavities by the oil itself. As the oil in the reservoir becomes warmed by the heat
of the lamp and therefore has less specific gravity the air enclosed in the cavity or
cavities also becomes warmed and as it therefore slightly expands it tends to lift
the dish and consequently increases its buoyancy. Therefore the more the specific
gravity of the oil becomes reduced the greater is the buoyancy of the dish.
A convenient way of forming the cavity or cavities is to make one or more
circular corrugations in the under side of the dish.
These lamps are not adapted for burning light or readily inflammable or
volatile oils.
Dated this 10th d
1000
Improvements in Wickless Oil Lamps or Night Lights.
I, JOHN FREDERICK DUKE of 160 Rosendale Road, West Dulwich in the
> County of Surrey, Chemist, do hereby declare the nature of this invention aud
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
My invention has reference to wickless oil lamps or night lights of the kind

page_text: which comprise a dish or cup with a small centra! vertical tube passing through it
and open at both ends. This dish or cup is of such buoyancy that it floats upon the
oil in an open reservoir, being however submerged just sufficiently to bring the
upper end of the tube down to a proper level relatively to the level of the oil.
The tube constitutes a wickless burner. These lamps have this serious objection.
As the oil becomes slightly warned its specific gravity decreases while that of the
dish remains the same. The dish consequently becomes slightly more submerged
so that the oil level in the tube correspondingly rises. The flame then increases,
and further warms the oil, until, by further slight submergence and further increase
of flame smoke is given off.
Now the object of this invention is to so construct the lanp that the buoyancy of
the dish will increase as the specific gravity of the oil diminishes owing to the beat
whereby the oil level in the tube is maintained at a constant level. For this
purpose I form one or more cavities or recesses in the under side of the dish so that
when the dish is placed upon the oil air becomes enclosed in the cavity or cavities by
the oil itself. As the oil in the reservoir becomes warmed by the heat of the lamp and
therefore has less specific gravity the air enclosed in the cavity or cavities also
becomes warmed and as it therefore slightly expands it tends to lift the dish and
consequently increases its buoyancy. Therefore the more the specific gravity of
the oil becomes reduced the greater is the buoyancy of the dish.
A convenient way of formning the cavity or cavities is to make one or more
circular corrugations in the under side of the dish.
The accompanying drawings represent a wickless oil lamp or night light
constructed according to my invention with a circular corrugation on the underside
of the dish as just explained.
Figure 1 is a side elevation of the lamp, Figure 2 a vertical section showing it
floating on a body of oil, and Figure 3 is a plan.
a is the dish, 6 the small central vertical tube passing through an aperture in
the dish and open at both ends, c is an annular recess formed by a circular corru-
gation on the underside of the dish. The dish a is preferably made of metal and
the tube of glass cemented to the metal.
These lamps are not adapted for burning light or readily inflammable or
volatile oils.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. In a wickless oil lamp or night light of the kind herein referred to, one or
more cavities or recesses in the under side of the dish or cup as and for the purpose
.described.
2. The improved wickless oil lamp or night light shown in the accompanying
drawings and herein before described.
J. C. MEWBURN & ELLIS,
55 and 56 Chancery Lane, London, Chartered Patent Agents.