IMPROVEMENTS APPLICABLE TO RAILWAY * CARRIAGE LAMPS
Year: 1877

page_text: LETTERS PATENT to John Pitt Kennedy, of Lupus Street, in the County of
Middlesex, Civil Engineer, and John Latham, of Folkestone, in the County of
Kent, Gentleman, and John Andrews Dryden, of Elsley Road, in the County
of Surrey, for the Invention of "IMPROVEMENTS APPLICABLE TO RAILWAY
* CARRIAGE LAMPS."
Sealed the 19th February 1878, and dated the 27th August 1877.
(
PROVISIONAL SPECIFICATION left by the said John Pitt Kennedy, John
Latham, and John Andrews Dryden at the Office of the Commissioners of
Patents on the 27th August 1877.
JOHN PITT KENNEDY, of Lupus Street, in the County of Middlesex, Civil
Engineer, and JOHN LATHAM, of Folkestone, in the County of Kent, Gentleman,
and JOHN ANDREWS DRYDEN, of Elsley Road, in the County of Surrey. "IMPROVE-
MENTS APPLICABLE TO RAILWAY CARRIAGE LAMPS."
The object of our Invention is to prevent the overflow of oil from the oil supply
chamber into the glass which which encloses the lamp or burner of railway carriage.
lamps. To this end we construct the lamp in such a manner as to maintain a regular
supply of oil to the burner, but to stop the supply when the oil rises to a certain fixed
level or point in the chamber surrounding the burner. To this end the supply pipe
which conducts the oil from the reservoir to the burner is provided at its exit aperture
with a valve which is connected to one end of a vibratory lever or arm mounted on
a centre pin in the oil chamber, and provided at its opposite end with a float.
As the oil rises in the chamber surrounding the burner, the float will rise with it
and will cause the valve to close the end of the oil supply pipe and prevent any
more oil from entering the chamber until the level therein sinks again, when on the
float descending the valve will be opened and small quantity more of oil will be
allowed to flow into the chamber.

page_text: It will be evident by this means, although a proper supply of oil to the burner
will always be ensured, there can never be any overflow while the valve is in
working order, as the float will always rise with the oil and will control the motions
of the valve.
:
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Pitt Kennedy, John Latham, and John Andrews Dryden in the
Great Seal Patent Office on the 27th February 1878.
JOHN PITT KENNEDY, of Lupus Street, in the County of Middlesex, Civil
Engineer, JOHN LATHAM, of Folkestone, in the-County of Kent, Gentleman, and
JOHN ANDREWS DRYDEN, of Elsley Road, in the County of Surrey.
" IMPROVE-
MENTS APPLICABLE TO RAILWAY CARRIAGE LAMPS."
The object of our Invention of improvements applicable to railway carriage lamps,
is to prevent the overflow of oil from the oil supply chamber into the glass which
encloses the lamp or burner of railway carriage lamps. To this end we construct
the lamp in such a manner as to maintain a regular supply of oil to the burner, but
to stop the supply when the oil rises to a certain fixed level or point in the chamber
surrounding the burner.
.. t
In the accompanying Drawing, Fig. 1 is a sectional elevation of a railway carriage
roof lamp constructed according to our improvements.
Fig. 2 is a transverse vertical section of the burner part of the lamp, drawn full
size; and Fig. 3 is a sectional plan view of the same.
The supply pipe a, which conducts the oil from the reservoir b to the oil chamber c
of the burner is provided (by preference) at its exit aperture with a valve which is
connected to one end of a vibrating lever or arm e, mounted on a centre pin e¹, fixed
at some convenient part of the oil chamber. This lever e is provided at its opposite
end with a float f, and as the oil rises in the chamber c surrounding the burner, the
float will rise with it and will cause the valve d to close the aperture at the end
of the oil supply pipe a, and prevent any more oil from entering the chamber c
until the level therein sinks again, when on the float f descending, the valve d will
be opened, and a small quantity more of oil will be allowed to flow into the
chamber c.
It will be evident that by this means (although a proper supply of oil to the
burner will always be secured) there can never be any overflow while the valve d
is in working order, as the float f will always rise with the oil and will control the
motions of the valve.
Air, to support the combustion of the oil in the burner, is conducted to the air
chamber g (surrounding the burner) by the air pipe h (Fig. 1), as in other roof lamps;
and in order to prevent the air that may be above the oil in the reservoir b from
forcing the oil down the pipe when the air is expanded by the heat of the
lamp, the reservoir b is provided with an aperture which is closed by the cork
stopper b', having a vertical groove cut in it to admit the air as the oil is consumed.
It will be seen that in Figures 1, 2, and 3, there is only one air pipe h, and that
the oil chamber c is of an oval shape, so that one side of the oil chamber c touches
the outer wall of the air chamber g, but in Fig. 4 the oil chamber c is of a circular

page_text: form, there is consequently an annular space g all round, and therefore two air
tubes h, h, of less diameter may be employed, as shewn in the sectional plan view,
Fig. 4.
Fig. 5 is a side elevation; and Fig. 6, a plan view of another modification in
which the air pipes are altogether dispensed with.
The same arrangement of vibrating lever valve and float, as in the other Figures
is employed, and therefore needs no further description.
Having now described our Invention of "Improvements Applicable to Railway
Carriage Lamps," and having explained the manner of carrying the same into effect,
we claim as the Invention secured to us by Letters Patent as aforesaid, the adapta-
tion to the exit aperture of the oil supply pipe of railway carriage lamps, of a valve
and float mounted on a vibrating lever or arm, for the purpose of controlling the
delivery of the oil to the oil chamber, as herein set forth."
In witness whereof, we, the said John Pitt Kennedy, John Latham, and
John Andrew Dryden, have hereunto set our hands and seals, the Twenty-
seventh day of February, in the year of our Lord One thousand eight
hundred and seventy-eight.
J. PITT KENNEDY. (L.S.)
J. LATHAM.
(L.S.)
J. A. DRYDEN.
(L.S.)