Improvements in and relating to Lamps or Lanterns, chiefly designed for use in Railway-carriages.
Year: 1890

page_text: Date of Application, 16th May, 1890
Complete Specification Left, 16th Feb., 1891-Accepted, 4th Apr., 1891
PROVISIONAL DI FUITICATION.
Improvements in and relating to Lamps or Lanterns, chiefly designed
for use in Railway-carriages.
I, JAMES THORNE, D.C.L., of 85, Gracechurch Street, in the City of London,
Merchant, do hereby declare the nature of this invention to be as follows:-
My invention relates to lamps or lanterns for use in railway-carriages and for
other purposes.
My said invention is chiefly designed to improve the construction and increase
the efficiency of roof-lamps for railway-carriages, and to adapt such lamps for
burning heavy oils which have a high flashing point.
In lamps of this kind heretofore used for burning heavy oils, an oil-reservoir of
annular form is placed beneath the wick-tube or burner; consequently, with such
lamps, the upper part and ends or sides of the carriage have not been properly
illuminated, the greater proportion of the rays of light being projected downward
instead of being dispersed throughout the carriage.
Now an important feature of my invention is the construction of a lamp which
can be safely used with heavy oils, and in which the main oil-reservoir is situated
in the upper portion of the lamp a considerable distance above the wick-tube or
burner. I am therefore enabled to so arrange the wick-tube or burner that the
flame is below the carriage-roof and below all such parts of the lamp as would
interfere materially with the proper dispersion of the rays of light; and I thus
ensure the adequate lighting of the carriage throughout.
I accomplish the desired result mainly by the provision of a small supplementary
reservoir which is kept supplied with oil from the main reservoir, and in which the
oil will be maintained at a predetermined level, the flow of the oil being auto-
matically arrested by the rising of the oil to this level in the supplementary reservoir
and the consequent prevention of the further admission of air to the main reservoir
to replace the oil discharged therefrom. The wick draws its supply of oil from
the said supplementary reservoir, and, as the oil in the latter is used, more oil flows
from the main reservoir into the said supplementary reservoir, thus maintaining the
oil at the desired level therein.
I prefer to make the main reservoir of segmental form instead of annular, as
heretofore, I thus obviate the liability to excessive oscillation, over-heating and
leakage. If desired, however, I may use an annular reservoir.
I provide the main reservoir with a tube which extends downward therefrom
and which is provided, preferably at or near its lower end, with a suitable valve.
This valve is so arranged that, when the said tube is inserted in the supplementary
reservoir, the said valve will be opened, and, when the said tube is removed from
such supplementary reservoir, the valve will close automatically. By placing the
valve at or near the lower end of this tube, I provide for retaining a larger propor-
tion of the oil in the main reservoir when lifted out of the lamp, than would be
practicable were the valve at the top of the said tube. The said tube is of such
length that it extends downward into the supplementary reservoir to the predeter-
mined level at which it is desired to maintain the oil therein. By using a shorter
tube than is employed when burning heavy oils, I can adapt the lamp for burning
colza and other oils.
Another important feature of my said invention is the construction of the lamp
in such a manner that the ingress for the air for supporting combustion and the
egress for the products of combustion are separate or distinct from each other,
and so that an efficient supply of air to the flame will be ensured, whilst unsteadi-

page_text: ness of the flame due to irregularities in the flow of the incoming air will be
prevented.
My improvements, moreover, afford the advantage that a portion of the air for
supporting combustion in the lamp, is drawn from the interior of the carriage, thus
keeping the oil-reservoirs cool, and drawing from the carriage the vitiated
atmosphere.
My improved lamp is provided with a small glass globe or combustion-chamber,
which is preferably secured at its upper end to a flange at the lower end of the
chimney or flue by means of a bayonet-joint or in any other convenient manner,
and which rests at its lower end upon a suitable support surrounding the wick-tube
or burner. I find it advantageous to make the said chimney or flue taper or conical
and to perforate the said flange for the purpose of permitting the passage of air
through the same and thus preventing the accumulation of highly heated air in the
upper part of the combustion-chamber. The usual globe or glass casing may, if
desired, be employed in addition to the said small glass globe or combustion-
chamber. Instead of using the larger globe or glass, I sometimes provide the
lamp with suitable legs upon which it may rest when removed from its place in
the carriage. I provide, moreover, a spring or other suitable device for holding
down the aforesaid chimney or flue and preventing displacement thereof or of the
said combustion-chamber.
Air is admitted from both the outside and the inside of the carriage, into the
upper part of the outer casing of the lamp, and is compelled to flow upwards;
the said air, or a portion thereof then passes through a perforated inner casing,
preferably of conical form, any superfluous air continuing to flow upward and
escaping at the top of the lamp. The air which passes through the said inner
casing flows downward between the same and the chimney or flue, and passes
through an air-passage at the side of or surrounding the oil-supply tube, into a
chamber around the wick-tube or burner. The air flows from this chamber through
a lamp-cone covering and surrounding the upper end of the wick-tube.
perforated plate, or a diaphragm of wire-gauze or the like is preferably arranged
at the top of the said chamber to prevent the entrance into the same of any cuttings
or other matter from the wick.
A
If more oil than required should escape from the main reservoir into the afore-
said supplementary reservoir, and the oil in this supplementary reservoir should
rise considerably above the predetermined level, it will overflow into. the said
air-chamber, and, by rising therein, will ultimately cut off the supply of air to the
burner and thus extinguish the light.
For adjusting the wick, I may employ the usual rack-and-pinion device. I find
it advantageous to so arrange this device that it can be operated only by means of
a key inserted into a hole or tube in the air-chamber or passage.
When my lamp is adapted for use with an annular or tubular wick, I prefer to
employ what I term a wick-holder, and to supply, for use in the lamp, short pieces
or lengths of tubular wick, which can be inserted in the said holder and will last
for any desired number of hours. The said wick-holder is made with an annular
passage one end of which is adapted for the reception of the wick, and the said
holder is provided with a rack to engage with the pinion of the wick-adjusting
device. In the other end of the said holder, which is suitably perforated or slotted,
I place some cotton, felt or other suitable material which will be in contact with
the wick inserted in the said holder, and will raise the oil from the supplementary
reservoir by capillary attraction and thus feed the said oil to the wick.
The main oil-reservoir is preferably arranged in an annular space between the
inner and outer casings, through which space the incoming air flows freely, thus
keeping the said reservoir cool.
:
The supplementary reservoir and the air-supply passage are made of such shape
in transverse section that no appreciable shadow will be cast thereby.
Although I have described my improvements more particularly as applied to

page_text: roof-lamps for railway-carriages, it is obvious that they are also applicable to
lamps for other purposes.
Dated this 16th day of May 1890.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.
Improvements in and relating to Lamps or Lanterns, chiefly designed
for use in Railway-carriages.
I, JAMES THORNE, D.C.L., of 85, Gracechurch Street, in the City of London,
Merchant, 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 :-
My invention relates to lamps or lanterns for use in railway-carriages and for
other purposes.
My said invention is chiefly designed to improve the construction and increase
the efficiency of roof-lamps for railway-carriages, and to adapt such lamps for
burning heavy mineral oils which have a high flashing point or for burning mineral
or vegetable oils.
An important feature of my said invention is the provision which I make for
conducting the air or a portion of the air for supporting combustion, through a
suitable pipe or passage from the upper part of the lamp into the lower end of a
glass globe or combustion-chamber, which surrounds the upper part of the wick-tube
or burner, and between which and the adjacent end of the said pipe or passage a
tight joint is made. This combustion-chamber is connected at its upper end with a
chimney or flue. I thus form a tubular space through which, while the lamp is
burning, a continuous flow of air will be maintained from the upper part of the lamp
directly to the space around the wick-tube or burner and thence through the said
combustion-chamber and the chimney. I thus ensure efficient combustion and
greatly increase the illuminating power of the lamp.
Another important feature of my said invention consists in providing for the
supply of oil from a main reservoir to the wick-tube or burner through the said air
pipe or passage, so that the air flowing through the latter will assist in keeping the
oil cool. In this manner, moreover, I simplify the construction of the lamp and
obviate the necessity for employing two separate pipes connecting the space around
the wick-tube or burner with the upper part of the lamp.
In my improved lamp, the main oil-reservoir is situated a considerable distance
above the wick-tube or burner, which draws its supply from a secondary or supple-
mentary reservoir suitably connected with the said main reservoir. I am, therefore,
enabled to so arrange the wick-tube or burner, in roof-lamps for railway-carriages,
that the flame is below the carriage-roof and is also below such parts of the lamp as
would interfere materially with the proper dispersion of the rays of light; I thus
ensure the adequate lighting of the carriage throughout.
The said main reservoir is tightly closed at its upper end, and is connected with
the secondary or supplementary reservoir by a suitable pipe so arranged that the
flow of the oil from the main reservoir will be automatically controlled by the rise
and fall of the oil in the said secondary or supplementary reservoir, the admission
of air to the main reservoir to replace the oil discharged therefrom, taking place
through the said pipe. The oil will, therefore, be maintained at a predetermined
level in the said supplementary reservoir.
I find it advantageous to so construct the lamp that the air or a portion of the
air for supporting combustion must pass through the said secondary or supple-
mentary reservoir, above the surface of the oil therein, either in contact with the
oil or otherwise.
Therefore any vapour formed will be carried away with the said air and the

page_text: accumulation of vapour in this reservoir will be effectually prevented; and the air
passing through this reservoir will also assist in keeping the oil cool.
My said invention, moreover, comprises other improvements hereinafter set
forth.
In the accompanying drawings I have shown how my said invention may be
conveniently and advantageously carried into practice.
Figure 1 is a vertical central section showing one form of my improved roof-
lamp.
Figure 2 is a longitudinal section on the line, x, Figure 1.
Figure 3 is a side elevation of the chimney and a glass combustion-chamber
attached thereto.
Figure 4 is a vertical section on the line y, y, Figure 1.
Figure 5 is a vertical central section showing another form or modification of my
improved lamp, and
Figure 6 is a side elevation of an annular or Argand burner hereinafter
mentioned.
Like letters indicate corresponding part throughout the drawings.
A is the outer casing of the lamp, which is provided with a rim or flange A'
whereby the lamp will be supported upon the carriage-roof when inserted in the
hole formed therein for its reception. Above this flange is a wind-guard A2
surrounding a part of the casing which is suitably perforated for the admission of
the air for supporting combustion. The upper portion or cover A³ of the casing A
is connected to the lower portion or body thereof by a hinge-joint at A* and is
provided at A5 with a suitable catch or fastening.
B is the main oil-reservoir, which is supported upon an annular plate C suitably
secured to the interior of the casing A; the said reservoir is situated between the
outer casing A and an inner casing C¹ extending upward from the plate C. This
reservoir B may, if desired, be of annular form as heretofore; I prefer, however,
to make the said reservoir of segmental form as shown, for example, in Figure 2; I
thus obviate or diminish the liability to excessive oscillation, over-heating and
leakage of the oil.
An annular reflector D is secured in the lower end of the casing A. and is formed
with an upwardly extending piece or flange D¹. E is the secondary or supple-
mentary oil-reservoir, one end of which is connected with the space above the
reflector D by means of a pipe F extending a short distance through and secured
in a suitable hole in the said reflector. The wick-tube or burner is secured in the
other end of the supplementary reservoir E.
The main reservoir B is provided with a tube a which extends downward there-
from and is provided at or near its lower end with a suitable valve b. This valve
is provided with a spindle which projects beyond the lower end of the tube a, so
that, when the said tube is inserted in its proper position in the supplementary
reservoir E, the valve-spindle will come into contact with the bottom of the said
reservoir and the valve will be opened, and, when the said tube is removed from
such supplementary reservoir, the valve will close automatically under the action
of gravity and the pressure of the oil. The main reservoir is filled with oil through
the pipe a, the said reservoir being inverted for this purpose. By placing this
valve at or near the lower end of the tube a, I provide for retaining a larger
proportion of the oil in the main reservoir both when the said reservoir is lifted out
of the lamp and after the filling of the said reservoir, than would be practicable
were the valve at or near the top of the said tube; and I thus prevent the discharge
of an undue quantity of oil into the supplementary reservoir when the main reservoir
is removed. The tube a is of such length that it extends downward into the supple-
mentary reservoir to the predetermined level of the oil therein. The tube a is
shown in the drawing of sufficient length for burning heavy mineral oils. By
using a shorter tube, I can, if desired, adapt the lamp for burning colza and
Similar oils.
The secondary or supplementary reservoir E is divided by means of a partition

page_text: or diaphragm E³ into two compartments. A tube or casing E' surrounds the tube a
and connects the lower compartment of the supplementary reservoir E with the
space above the annular plate C, the said tube or casing being suitably fixed at its.
lower end in the partition E and at its upper end in the said annular plate C. The
lower compartment is in communication with the upper compartment through a
hole Es formed in the tube E³, so that any vapour given off by the oil in the lower-
compartment will escape into the upper compartment and be carried away with the
air which flows through the latter. Moreover air can pass through the hole E5-
and enter the main reservoir through the pipe a when the level of the oil in the
supplementary reservoir falls below the lower end of the said pipe a. The wick-tube
or burner extends through and is firmly fixed in the said partition E³. If desired,.
instead of forming a hole in the tube or casing E, one or more holes may be formed.
in the said partition for the purpose above specified.
Although it is more advantageous to divide the supplementary reservoir as above
described, the partition E³ may, if desired, be dispensed with, the air being allowed.
to pass through the said reservoir in contact with the oil therein.
My improved lamp is provided with a small glass-globe or combustion-chamber c,.
which is firmly secured at its upper end to a flange d' at the lower end of the
chimney or flue d, and which bears at its lower end upon a suitable support.
surrounding the wick-tube or burner.
In the lamp shown in Figure 1, the said combustion-chamber rests upon the
flange el of a lamp-cone e arranged above and around the wick-tube or burner G, a
ring or washer of asbestos or other suitable material being placed between the
said flange e¹ and the combustion-chamber e so as to make a tight joint. I find it
advantageous to make the said chimney or flue taper, and to perforate the flange d
of the said chimney as at d² to permit the passage of air through the same and thus.
prevent the accumulation of highly heated air in the upper part of the combustion-
chamber. The said flange d¹ may, if desired, serve as a reflector. The lamp-cone e
is preferably connected by a hinge-joint with the supplementary reservoir E, so.
that it can be readily turned aside and need not be detached to permit access to
the wick.
The usual globe or glass casing may, if desired, be employed in addition to the
said small glass globe or combustion-chamber. I sometimes provide the lamp with
suitable legs upon which it may rest when removed from its place in the carriage..
Or I make the supplementary reservoir E with a flange E¹ (Figures 1 and 4).
whereby the lamp will be maintained in an upright position when placed on a level.
surface. I provide, moreover, in the cover A of the lamp, a spring g or other
suitable device for holding down the chimney or flue d and preventing accidental
displacement thereof or of the combustion-chamber c, the latter being thus pressed
firmly against the washer or packing-ring fat its lower end.
In the cover A' of the lamp shown in Figure 1, is secured a perforated inner
casing H, preferably of conical form, the lower end of which fits the upper end of
the inner casing C₁ and through which the air for supporting combustion must pass,.
any superfluous air which may enter through the perforations in the outer casing A
escaping at the top of the lamp. The air which passes through the said inner
casing H flows downward between the casing C' and the chimney or flue d, and
passes through the pipe F into the upper compartment of the supplementary
reservoir E, whence it flows through the lamp-cone e. The flame is thus supplied
with the air necessary for supporting combustion, and any vapour arising from the
oil in the secondary reservoir E will be carried away with the said air. A
perforated plate or a diaphragm or cap of wire-gauze or the like is preferably
arranged beneath the lamp-cone e to prevent the entrance into the supplementary
reservoir of any cuttings or other matter from the wick, and also to prevent the
ignition of any vapour inside the supplementary reservoir.
It will be seen that, with the exception of the combustion-chamber c and
chimney d, all the parts of the lamp are so connected that they are not liable to be
mislaid or lost. The said combustion-chamber and the chimney are, moreover,.