Improvements in Lamps for Railway-carriages.
Year: 1893

page_text: Date of Application, 23rd Oct., 1893
Complete Specification Left, 23rd July, 1894-Accepted, 25th Aug., 1894
PROVISIONAL SPECIFICATION.
Improvements in Lamps for Railway-carriages.
We, WILLIAM MCLAREN, of Moorgate Works, Moorfields, and CHARLES
RICHARDS, of 156 Dalston Lane, Hackney, both in the County of London,
Engineers, do hereby declare the nature of this invention to be as follows:-
The object of this invention is to construct, for use in railway-carriages and the
like, an improved lamp of simple construction, which is adapted to burn either
oil-gas or coal-gas with economy and to emit a steady and uniform light unaffected
by draughts, or by currents of air set up suddenly by the banging of doors.
It is an important feature of lamps constructed according to this invention
that the supply of air to support combustion is drawn from the interior of the
carriage, and is therefore warmed; furthermore, the air, after being admitted to
the lamp from the interior of the carriage is not taken immediately to the combustion-
chamber until it has received a further preliminary warming, consequently the
supply of air does not act disadvantageously to chill the flame and diminish the
light in the manner frequently experienced in quick-travelling trains especially
when passing through tunnels with lamps of the ordinary kind wherein the air-
supply is drawn from outside the carriage and delivered direct to the combustion
chamber.
According to one method of carrying this invention into practice, we construct
a cylindrical frame which is suitably flanged to adapt it for reception in the lamp-
orifice in the roof of the vehicle and for other purposes.
To the lower end of the said frame a ring is hinged. The said ring, which may
for instance be L-shaped in cross-section, is adapted to receive and retain a hemi-
spherical or other suitable glass and is provided with a bolt and lock-nut or other
suitable device whereby it can he held up in position in a suitable recess or seating
in or upon the lower part of the frame. One edge of the said ring is scalloped or
The said ring is
the ring is perforated, for a purpose hereinafter specified.
channelled or grooved to receive a layer of felt or other suitable material to serve
as packing, which when the ring is held up as aforesaid will make a tight joint with
the lower edge of a circular rim, which, at its upper edge is arranged to make a
tight joint with the interior of the frame so that an annular air chamber closed at
the top and open at the bottom is provided. The circular rim is perforated at
intervals at about the middle of its depth and a circular baffle, open at the bottom
and closed at the top, is secured upon the inner circumference of the rim and
arranged to divert downward the air which passes through the said perforations.
The said circular rim, just above the edge which bears upon the packing aforesaid
has the outer circumference of an annular and approximately horizontal curved
reflector attached thereto. The inner circumference of the said reflector is in turn
connected to the lower end of a central tubular chamber which is extended upward
to communicate with a chimney hereinafter referred to.
The said reflector also is perforated at intervals near its outer circumference. In
the lower portion of the said central chamber a hollow casting forming the
regenerating chamber is supported. Said regenerating chamber is closed at the
top and open at the bottom. It is tapered inward from about the middle to
the upper and lower ends, which latter is flanged outward. The interior of the
said casting is connected by side passages with the space exterior to the said central
chamber. A gas supply tube passes across the upper part of the frame through
the side passages of the casting aforesaid. It may be closed at one end or may be
continuous and is provided with a branch which extends down through the said

page_text: hollow casting and ends in a burner just below the flanges aforesaid. A perforated
diaphragm extends across the space between the said branch and the inner surface
of the casting, which diaphragm supports the inner tube and also serves to check
the fierceness of the draught.
At the lower end of the gas tube just above the gas nipple or burner I sometimes
provide a disc to spread the air and cause same to impinge more powerfully on the
lower flange before mentioned of the regenerating chamber. This device improves
the light very materially.
A cap or cover is hinged at one side to the frame near the upper edge thereof,
and at the opposite side is fitted with a catch or an equivalent retaining device.
The said cap or cover normally closes the upper end of the cylindrical frame and
is constructed as follows:-
•
Two concentric conical tubes are secured to a domed disc which is adapted to
rest upon the said frame. The inner tube passes through the said domed disc and
communicates at its lower end with the interior of the regenerating chamber
aforesaid upon the upper end of which it fits, and at its upper end communicates with
the interior of the outer concentric tube, which encircles it and is closed at the top.
Perforations are made in the domed disc to allow air to pass therethrough into the
annular space between the inner and outer tubes. At the upper end of the said
space between the concentric tubes is a coned ring by which exit of the air from
the said space is prevented, except by way of perforations made therein at points
near to the inner tube. Above the said coned ring, the outer tube is perforated at
points just opposite thereto, the edges of the perforations being burred outward to
check any sudden movement of air theretbrough. Around the outer tube, opposite
to the said perforations with the burred edges, is a circular wind-guard supported
by brackets attached to the exterior of the outer tube. The wind guard is open
top and bottom for the passage of air therethrough.
The outer circumference of the said domed disc may be constructed with two
thicknesses of metal so arranged that an annular air-chamber is left between them.
Perforations may be made on the lower one of the two thicknesses so that air can
pass from outside the cylindrical frame into the annular air chamber from under an
overhanging flange with which the domed disc is provided, and other perforations
enable the air to pass from the annular chamber into the interior of the said frame,
and thence into the annular space around the flue to assist in keeping the latter
cool. In some cases these holes are dispensed with.
In a lamp thus constructed the air-supply to support combustion passes from the
interior of the carriage over the scalloped portions and through the perforations of
the ring which holds the glass, and then flows to the annular air-chamber formed
by the metal rim which beds on the felt as aforesaid. From this air-chamber the
air passes through the perforations in one wall thereof, and is deflected down by
the deflector or baffle and then the greater portion thereof passes to the regenerating
chamber, but a small portion thereof passes through the holes in the deflector
direct to the lower side of the flame. The products of combustion pass upward
between the inner part of the regenerating chamber and the outer central cylindrical
chamber, warming the air-supply which is in contact with the exterior of the latter
and the interior of the former, and the said products of combustion finally pass up
the chimney and out through the several perforations in the concentric tubes and
their appurtenances aforesaid.
Dated this 23rd day of October 1893.

page_text: Improvements in Lamps for Railway-carriages.
I, WILLIAM MCLAREN, of Moorgate Works, Moorfields, and CHARLES
RICHARDS, of 156 Dalston Lane, Hackney, both in the County of London,
Engineers, do hereby declare the nature of this invention, and in what manner
the same is to be performed, to be particularly described and ascertained in and
by the following statement :-
The object of this invention is to construct, for use in railway-carriages and the
like, an improved lamp of simple construction, which is adapted to burn either
oil-g
gas or coal gas with economy and to emit a steady and uniform light unaffected
by draughts or by currents of air set up suddenly by the banging of doors for
example.
It is an important feature of lamps constructed according to this invention that
the supply of air to support combustion is drawn from the interior of the carriage,
and is therefore warmed; moreover this assists in ventilating the carriage.
Furthermore, the air, after being admitted to the lamp from the interior of the
carriage is not taken immediately to the combustion-chamber until it has received
a further preliminary warming, consequently the supply of air does not act
disadvantageously to chill the flame and diminish the light in the manner
frequently experienced in quick-travelling trains especially when passing through
tunnels with lamps of the ordinary kind wherein the air-supply is drawn from
outside the carriage and delivered direct to the combustion chamber.
In order that our invention may be clearly understood, we will now proceed to
describe the same with reference to the accompanying drawing which is a sectional
elevation of a railway-carriage lamp constructed according to our said invention.
A is the roof of the vehicle having a lamp orifice A' therein. B is a cylindrical
frame fitting the lamp orifice A¹ and provided with a flange B¹ which is secured to
the roof A by screws B³. C is a ring hinged at C' to the lower part of the flange B¹
and adapted to receive and retain a hemispherical or other suitable glass D.
Said ring C is provided with a bolt and lock-nut E or other suitable device
whereby it can be held up in position in a recess B in the lower part of the
frame B. One edge of the ring C is scalloped as shewn at C² so as not to make
an air-tight joint with the frame B for a purpose hereinafter specified. Or the
ring C may be perforated with holes C³, C³ as shewn. The scalloped edge may
C₁
be employed with the holes if desired. The ring C is provided with a groove
in which a layer C of felt or other suitable material is placed to serve as
packing, which when it is held up as aforesaid makes a tight joint with the lower
edge of a circular rin F which is secured by its upper edge to the frame Bas
shewn. Said rim F is perforated at intervals as shewn at F, F and a circular
baffle F is secured upon the inner periphery of the rim which diverts downward
the air passing through the perforations.
G is a curved reflector attached to the rim F by its outer circumference and
connected at its inner circumference to the end of the central tubular chamber H
which communicates with the chimney. Said reflector is perforated at intervals
near its outer circumference as shewn at G, G¹, but we preferably arrange that
the united area of said perforations G', G' shall be considerably less than half the
united area of the perforations F', F in the rim F.
I is a hollow casting supported in the lower portion of the central chamber H
and forming a regenerating chamber. Said generating chamber is closed at the
top as shewn at l' and open at the bottom which is provided with a flange [2.
The interior of the regenerating chamber is connected by side passages 1³, 1 with
the space exterior to the central chamber H and a gas supply tube J provided

page_text: with a tap J¹ extends across the upper part of the frame B through the
passages I, I in a manner well known. The gas supply tube may be closed at
one end as shewn or it may be continuous and it is provided with a branch J'
which extends down through the regenerating chamber I ending in a suitable
burner J just below the flange 12 of the regenerating chamber. A perforated 5
diaphragm J is provided between the branch and the casting I which supports
the inner tube and also serves to check the fierceness of the draught. I prefer
to attach to the branch J a hollow shell J' the branch J' being perforated with
holes J as shewn. The gas passing down the branch J will then fill the shell J
flowing in the direction of the arrows through the holes J and will therefore be
brought nearer to the chimney and be heated to a greater degree than would be
the case if such gas merely passed through the tube J*. Moreover the space
inside the casting I is still further restricted by the said shell which assists the
diaphragm J in checking the draught.
Jis a disc placed just above the burner J' for spreading the air and causing the
same to impinge more powerfully on the flange 12 of the regenerating chamber.
This device improves the light very materially.
The cap or cover which normally closes the top of the frame B will now be
described. K is a domed disc hinged to the frame at one side and provided with
a suitable catch or clasp at the opposite side. To the said disc are secured two
concentric conical tubes the inner one K¹ of which passes through said disc and
communicates at its lower end with the interior of the regenerating chamber H
fitting upon the upper end of said chamber. Said inner tube communicates at its
upper end with the outer tube K2 which is closed at the top as shewn. The
domed disc K is perforated as shewn at K', K' so that air can pass into the
annular space between the tubes K1, K2, said space being closed at the top by a
conical partition K which is perforated at K, K as shewn. Above the conical
partition K the outer tube K is perforated as shewn at K, K* the edges of the
perforations being burred outward to check any sudden movement of air there-
through and around the said outer tube. Opposite to the perforations K, K® is a
circular wind-guard K' supported by brackets K attached to the exterior of the
outer tube. The wind guard is open at the top and bottom for the passage of air
therethrough.
The outer circumference of the domed disc K may be constructed with two
thicknesses of metal so arranged that an annular air-chamber is left between them.
Perforations may be made on the lower one of the two thicknesses so that air
can pass from outside the cylindrical frame B into the annular air chamber from
under an overhanging flange with which the domed disc is provided, and other
perforations enable the air to pass from the annular chamber into the interior of
said frame, and thence into the annular space around the flue to assist in keeping
the latter cool. In some cases these holes are dispensed with. This construction
is not shewn in the drawings.
In a lamp constructed as above described the air-supply for supporting
combustion passes from the interior of the carriage between the ring C and the
frame B, over the scalloped portions C³ or through the perforations C³, C³ of the
ring C, or both over the said scalloped portions and through the perforations if
both be present, and then flows to the annular chamber formed between the rim F
and the frame B. From this chamber the air passes through the perforations F¹, F
and is deflected down by the deflector or baffle F and then the greater portiou
thereof passes by the channels 1' to the regenerating chamber and to the upper
side of the flame impinging on the plate J' before reaching the flame. A small
part of the air passes through the holes G', G' in the reflector G direct to the
lower side of the flame. The products of combustion pass upward between the
wall of the regenerating chamber and the wall H of the central cylindrical
chamber warming the air-supply which is in contact with the exterior of the latter
and the interior of the former and then passing to the chimney K'. The said
products of combustion finally pass into the air through the perforations K of

page_text: the outer chimney. The arrows on the drawing shew the directions of the air and
gas currents.
If from any reason a sudden gust of air is forced through the holes F', F' so as
to considerably increase the air pressure in the space immediately above the
reflector the air passes out by the perforations K K direct to the upper part of
the outer chimney K' and no increase of draught is caused through the regenerating
chamber. This is of great importance as the flame is thereby prevented from
flickering and all danger of it being blown out is avoided.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that
what we claim is :-
1. A regenerative lamp for use in railway-carriages and the like, and so
constructed that the air-supply for the combustion is drawn from the interior of
the carriage or the like, substantially as described.
described with reference to the
2. A lamp constructed substantially as
accompanying drawing and operating as specified.
Dated this 23rd day of July 1804
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicants.