IMPROVEMENTS IN LAMPS
Year: 1878

page_text: LETTERS PATENT to George Seagrave, of Mark Lane, in the City of London,
for the Invention of "IMPROVEMENTS IN LAMPS."
PROVISIONAL SPECIFICATION left by the said George Seagrave at the Office
of the Commissioners of Patents on the 3rd October 1878.
GEORGE SEAGRAVE, of Mark Lane, in the City of London.
LAMPS."
"IMPROVEMENTS IN
My Invention relates to lamps for railway and other carriages and for other
purposes wherever a lamp is liable to be shaken, and it has for its object chiefly
preventing the overflow of the oil into the air space or globe under the shaking
motion to which the lamp is subjected.
In carrying out my Invention as applied for example to an argand lamp, in order
to effect the object before mentioned I provide an annular overflow or drip cup sur-
rounding the oil enp, in which overflow or drip cup the oil which is thrown over
the top of the oil cup is received, the overflow or drip cup extending up to any
necessary height above the level of the oil in the oil cup. The top of the overflow
or drip cup forms a hood, which promotes the distribution of air to the burner. The
Invention is also applicable to burners having flat wicks by making the parts of a
corresponding shape.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said George Seagrave in the Great Seal Patent Office on the 1st April
1879.
GEORGE SEAGRAVE, of Mark Lane, in the City of London.
LAMPS."
"IMPROVEMENTS IN
My said Invention relates to lamps for railway and other carriages and for other
purposes wherever a lamp is liable to be shaken, and it has for its object chiefly
preventing the overflow of the oil into the air space or globe under the shaking
motion to which the lamp is subjected.
In carrying out my said Invention as applied for example to an argand lamp, in
order to effect the object before mentioned I provide an annular overflow or drip
cup surrounding the oil cup, in which overflow or drip cup the oil which is thrown
over the top of the oil cup is received, the overflow or drip cup extending up to
any necessary height above the level of the oil in the oil cup. The overflow or drip
cup also serves to promote the distribution of air to the burner.
And in order that my said Invention may be fully understood, I shall now proceed
more particularly to describe the same, and for that purpose shall refer to the several
Figures on the annexed Sheet of Drawings, the same letters of reference indicating
corresponding parts in all the Figures.
Figure 1 of the accompanying Drawings represents a sectional elevation of a
portion of a lamp having my said Invention applied thereto, and Figure 2 is a
vertical section taken at right angles to Figure 1, the globe being omitted from the
Figure; Figures 3 and 4 are sectional elevations of portions of lamps, illustrating
two respective modifications of my said Invention.
Referring to Figures 1 and 2, A is the tube of an argand burner surrounded by
the tubular wick a; B is an oil cup, which is formed by the tube A, by the outer
wall or side b, and by the bottom c. In the examples illustrated the oil cup is
assumed to be supplied with oil by means of tubes C from an oil reservoir above,
but my Invention, as herein-after particularly described, is equally applicable
whenever an oil cup separate from the reservoir is employed, wherever that reservoir
may be situate.
According to my said Invention I provide around the oil cup B an annular over-
flow or drip cup
formed by the exterior of the oil cup, by the outer wall or side d,
and by the bottom c, the said overflow or drip cup being intended for the reception
of any oil which may be ejected over the top of the oil cup B by the shaking
motion to which the lamp is subjected. Air for supporting combustion is supplied
to the burner E by pipes F communicating with the atmosphere at the upper part
of the lamp, and at their lower ends terminating in a chamber e which forms part
of the burner. From this chamber the air ascends to the flame through the centre
of the tube A, and also through the annular passage ƒ surrounding the overflow or
drip cup D and terminating below the " cone g. The overflow or drip cup may
be provided at its upper part with a hood h, as shewn in Figure 3, which tends to
prevent the wash of oil from the oil cup into the air chamber or globe.
It is found advantageous in practice to employ a separate wick tube fitting round
the tube A, an example of which arrangement is illustrated in Figure 4. A' is the
wick tube, composed of the inner tube a¹, which fits round the wick tube A, and
the outer tube a², which fits within the outer wall b of the oil cup B, the two parts
a¹, a², being united at their lower ends. The wick a is contained between the two
portions a, a, of the wick tube, the outer portion a² of which is slotted so as to
admit of the oil gaining access to the wick. The wick tube carries at its upper end
a flange h¹, which rests upon the top of the oil cup B, and which flange may be
extended, as shewn in the Figure, so as to form the hood for preventing the wash or
ejection of the oil;
In the class of lamp illustrated in the Drawings the whole of the parts herein-
before referred to (with the exception of the upper portions of the oil tubes C and

page_text: air tubes F) are enclosed in a globe G, the air within which becomes heated by the
combustion in the burner. It is preferred to utilize this heated air for promoting
combustion by providing at the lower part of the chamber e openings fitted with
tubes projecting inwards in an inclined direction, through which air will be drawn
into the burner from the interior of the globe G. Although by the use of the over-
flow or drip cup D, in accordance with my said Invention, the liability to accidents
is reduced to a minimum, the tubes i provide additional security against the acci-
dental extinction of the light, as in the event of any contingency occurring causing
the efflux of oil from the oil cup or overflow or drip cup into the lower part of the
chamber e. The tubes i will admit of the escape of the oil to the interior of the
globe G before the oil can have accumulated within the chamber e to such an extent
as to cut off the supply of air by the tubes F to the said chamber.
My said Invention is also applicable to burners having flat wicks by making the
parts of a corresponding shape.
Having now described and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be used or carried into
effect, I would observe in conclusion that what I consider to be novel and original, and
therefore claim as the Invention secured to me by the herein-before in part recited
Letters Patent is,--
The employment in combination with an oil cup of an overflow or drip cup, sub-
stantially as and for the purposes herein-before described.
In witness whereof, I, the said George Seagrave, have to this my Specification
set my hand and seal, this Twenty-ninth day of March, One thousand eight
hundred and seventy-nine.
GEO. SEAGRAVE. (L.S.)