Improvements in Gas Lamps.
Year: 1895

page_text: Date of Application, 27th Nov., 1895
Complete Specification Left, 27th Feb., 1896-Accepted, 25th Apr., 1896
PROVISIONAL SPECIFICATION.
Improvements in Gas Lamps.
I, THOMAS COOPER JOHN THOMAS, of 93 Manor Park Road, Harlesden, N.W.
Engineer, and WILLIAM MUDD STILL, of 24 Charles Street, Hatton Garden, E.C.,
Manufacturer, do hereby declare the nature of this invention to be as follows:-
This invention has reference to improvements in gas lamps of the kind having
one or more flat flame burners arranged within a closed bowl or chamber below a
reflector and suitable for overhead lighting as for example railway carriage and
street lighting.
A lamp according to my invention is constructed with one or more flat flame
burners carried by the lower portion of a gas supply pipe and arranged to project
horizontally or nearly so from the lamp bowl or casing towards the centre of the
lamp, and above the burner or burners and separate therefrom is a reflector
provided near its periphery with one or more air outlet openings preferably of
concave-convex form in face view, located above the burner or above each burner,
and each in communication with an air chamber the inlet or inlets to which is or
are out of line with the said air outlet opening or openings so that there will be no
dark space in the reflector due to such opening or openings. The arrangement is
such that when the lamp is burning, air will issue through the air outlet opening,
or each of them and direct the flame extending from the burner below towards an
exit opening or openings in the top or central portion of the reflector. A lamp
constructed as described whilst suitable for burning ordinary coal gas, is specially
suitable for burning oil-gas. In one arrangement of our lamp, there are two
oppositely arranged horizontal or slightly inclined burners carried by elbows
attached to a horizontal pipe that is bent to a circular form, is located between the
lamp bowl and the outer periphery of the reflector, and is connected to a gas supply
pipe which in one construction is hinged or pivoted to the main gas supply pipe so
that it can be swung out of the casing of the lamp for the purpose of cleaning or
repairing the lamp bowl, and in another construction is fixed to such main gas
supply pipe. In the former case, the bent pipe carrying the burners is arranged
to be suspended within the lamp bowl. In the latter case the said bent pipe may
be outside the lamp body or case through which the elbows carrying the burners
and which are made removable are arranged to project. The reflector is provided
with an annular air supply chamber, formed by and between the reflector and a
lower outwardly extending annular portion of the chimney which is perforated for
admission of air to the chamber, the perforations being arranged at about right
angles to the two air outlet openings in the reflector. The top wall of the air
chamber is enamelled or provided with an enamelled plate above each air outlet
opening. The lower portion of the chimney may be cast in one with the chimney
proper and consists of a hollow convex part provided with a perforated horizontal
annular flange and two downwardly extending annular ribs to which the reflector
is suitably secured, as by screws, so as to form the annular air chamber. The
outer rib may be notched at its lower edge to form air holes through which air can
pass into the lamp bowl for the purpose of keeping it cool, or the lower part of
the chimney may be of spun or stamped sheet metal and consists of an enlarged
central part, to which the chimney proper is attached and a perforated outer
annular Hanged part that is arranged in close contact with raised central and outer
portions of the reflector, which, in this case is or may be provided with an annular

page_text: row of holes for supplying air to the lamp bowl. The central portion of the
reflector is formed with a raised or recessed central part of dished, conical or other
shape and pierced with an annular row or rows of holes for the escape of the
heated air and products of combustion from the bowl into the chimney, as described
in the Specification of Letters Patent No. 25,087 of 1893 granted to one of us,
viz. the said Thomas Cooper John Thomas. In some cases however, the reflector
may be constructed with a central exit opening at the base of the chimney.
In another construction, the reflector is made in two annular parts, connected
together by distance pieces and screws so as to form an annular air-way that is in
communication on the outer periphery with the external atmosphere and at the
inner periphery with the lamp bowl above the burner or burners. The inner and
upper part of the reflector carries the lamp chimney which is open at the bottom,
and the outer and lower part of the reflector is adapted to rest upon the flange of
the lamp bowl or casing.
Burners and reflectors constructed and arranged as herein before described can be
readily applied to the existing casings and fittings of railway carriage lamps of the
Pintsch and Pope type.
We, THOMAS COOPER JOHN THOMAS, of 93 Manor Park Road, Harlesden, N.W.,
Engineer, and WILLIAM MUDD STILL, of 94 Charles Street, Hatton Garden, E.C.,
Manufacturer, 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:-
This invention has reference to improvements in gas lamps of the kind having
one or more flat flame burners arranged within a, closed bowl or chamber below a
reflector and suitable for overhead lighting, as for example railway carriage and
street lighting, as we will now proceed to explain by reference to the accompanying
drawings wherein
Figs. 1 and 2 are vertical sections at right angles to each other, shewing our
invention applied to a railway carriage roof lamp of the well known Piutsch type.
Figs. 3 and 4 are respectively upper and underside views of the reflector shown
in Figs. 1 and 2.
In this arrangement there are two oppositely arranged horizontal flat flame
burners 1 of the ordinary well known Pintsch kind carried by elbows 2 attached to
a horizontal pipe 3 that is bent to a circular form, as indicated in dotted lines in
Fig. 3, the burners being so arranged within the lamp bowl 4 as to project towards
the centre of the lamp, flame that presents a broad or extended. surface to a loose
removable reflector 5. The pipe 3 is located between the lamp bowl 4 and the
outer periphery of the reflector 5, and, at its central part, is connected to a vertical
gas supply pipe 3ª which, by the horizontal pipe 3b into which it is screwed, is
hinged or pivoted, in the well known manner, to the main gas supply pipe 6,
so that the combined gas supply pipes 3, 3ª, 3b with burners 1 can, after turning
back the lamp head 7 and lifting out the reflector, be swung out of the lamp
casing 7 for the purpose of cleaning or replacing the lamp bowl or burners.
The reflector 5, which merely rests upon a ring 4 and is notched at to
accommodate the pipe 3", is provided with an annular air supply chamber 5

page_text: formed by and between the reflector, the lower enlarged part 8ª of the chimney 8,
and an outwardly extending annular plate 9, these parts being secured together so
as to form a combined reflector, air supply chamber and chimney. The plate 9
forming the top of the air chamber, is perforated, as shown at 9", for admission of
air to the chamber, the perforations being arranged at about right angles to the
two air outlet openings 10 in the reflector. These openings 10, which are of
comparatively large size and of concave-convex shape, are each located above an
elbow 2 so as to be in proximity to the burner 1 carried thereby so that the air
issuing through it will impinge upon the upper surface of the flame extending from
the burner, and impart a curved form to such flame and direct it towards the
central portion of the reflector 5. The reflector is formed with a raised or
recessed central part 5 that may be of dished shape, as shown, or of conical or
other shape, and is pierced with an annular row (or rows) of holes 5d for the escape
of the heated air and products of combustion from the bowl 4 into the chimney 8,
as described in the Specification of Letters Patent No. 25087 of 1893, granted to
one of us, viz. the said Thomas Cooper John Thomas. The underside of the top
wall 9 of the air chamber is or may be enamelled or provided, with an enamelled
plate, above each air outlet opening 10 so that no dark space will be seen at this
part.
By providing a comparatively large air opening above each burner and making
the reflector with a central raised portion, as hereinbefore described, liability of
the flat flame smoking or blackening the reflector is obviated, both when the gas
is turned full on to the burner, and also when supplied to the burner only through
the by-pass.
Figs. 5 6 and 7 are similar views to Figs. 12 and 4 respectively, showing the
invention applied to a railway carriage roof lamp of the well known Pope type.
In this arrangement, which is substantially like that illustrated in Figs. 1 to 4
inclusive, the flat flame burners 1 are directly attached to the inwardly beut ends 2
of the circularly curved pipe 3, which is slightly inclined and suspended as before
by the hinged or pivoted pipes 3ª, 3b, and the air openings 10 formed in the
reflector above the burners, are each of a triangular shape, (see Fig. 7) which, so
far as trials have shewn, gives the best results, especially when the lamp is burning
only with the gas supplied through the by-pass, at which time the Hame has a
tendency to smoke or blacken the reflector.
There may be only one burner, or more than two burners, arranged or each
arranged as described below an air exit opening communicating with an air supply
chamber in the reflector above. Also the burner or burners instead of being
carried by a hinged or pivoted gas supply pipe 3ª as described, may be carried by
a fixed gas supply pipe, in which case the bent pipe 3 may be outside the lamp
body or casing 7 through which the elbows or bent ends 2, which are then made
removable, are arranged to project. We prefer however the arrangement shown,
as it enables our invention to be readily and quickly applied to the existing lamp
bodies of the Pintsch and Pope lamps without disturbing them, all that is necessary
to be done for this purpose being to replace the ordinary dependent gas supply
pipe and burner or burners by our pipes 3, 3ª and burner or burners 1, and to lift.
out the existing reflectors and replace them by our improved reflectors.
Figs. 8, 9 and 10 show a modified construction of combined reflector, air
chamber and chimney, in which the raised central portion 5° of the reflector 5,
nstead of being provided with a row of exit openings 5 as in Figs. 1 to 7, has a
single central exit opening 5d to better enable the lamp to be lighted from the top
of the chimney 8 without removing the reflector and attached parts. The said
exit opening may be of circular form, as seen in full lines, or in the form of an
longated slot, as shown in dotted lines in Fig. 10, or in other form as may be
lesired. In the hereinbefore described arrangements Figs. 1 to 7, the combined
eflector, air chamber and chimney are of spun or stamped sheet metal. In the
xample now being described the reflector proper 5 only is of spun or stamped
heet metal and it is secured, as by screws 5*, to a dished and flanged top plate 9,

page_text: which, as well as the chimney is of cast metal. This construction enables the
reflector proper to be easily and cheaply renewed when necessary.
When the reflector is to be used with a single burner arranged as described, it
will of course be provided with a single comparatively large air supply opening 10
of crescent, triangular, or other equivalent shape for example plano-convex shape,
arranged above or in proximity to it.
In the reflector shown in Figs. 11 and 12, the annular air-chamber 5b com-
municates with the external atmosphere through holes 9 in its top as before, but
the air exit opening 10 therefrom into the bowl or chamber 4 is of annular form
and arranged concentrically with the axis of the lamp. A curved annular
deflecting plate 9 carried by the upper of the two parts of which the reflector is
made, and arranged to overlap the annular opening 10%, as shown in dotted lines
in Fig. 11, may be employed to better direct the issuing air upon the gas flame or
flames below.
We do not limit ourselves to the use of an air way. 10 of either of the shapes
shown, as other forms may be used so long as they be each euch as to enable a
comparatively large body of air to be delivered upon the upper surface of the
flame below it, so as to at all times prevent the same from blackening the reflector.
We have, however, obtained the best results by using clear unobstructed openings 10
of the general type shown, that is to say having their widest part at the centre and
in line with the burner below, and decreasing in width to zero on each side.
Lamps constructed as described, whilst specially suitable for burning oil-gas,
such as is now commonly used for railway carriage roof lamps, is suitable also fer
burning ordinary coal gas, as for example in lamps intended for street lighting.
For the latter purpose, the lamps bowls may be each carried by a binged ring
adapted to open downward, as well understood.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed we would observe that in
some respects the lamps hereinabove described are in accordance with the invention
claimed in Thomas' prior Specification No. 435 of 1895 wherein he has described
a lamp constructed with a burner or burners adapted to project flame that presents
a broad or extended surface to a reflector constructed with a comparatively large
air supply opening located above or in proximity to the burner or with more than
one such opening each located above and in proximity to a burner, and with an
exit for hot gases, but what we claim is :-
1. In a gas lamp of the kind referred to, the arrangement of the reflector
independently of and above the burner or burners, substantially as herein
described.
2. An overhead gas lamp comprising a lamp body or casing with closed bowl,
a gas supply pipe hinged or pivoted to the main gas supply pipe so that it can be
swung in and out of the bowl and provided with one or more burners adapted to
project flame that presents a broad or extended surface to a removable reflector
that is supported independently of the gas supply pipe and burner or burners, and
is constructed with a comparatively large air supply opening arranged above or in
proximity to the burner, or with more than one such opening each arranged above
and in proximity to a burner, and with an exit opening or openings for hot gases,
substantially as described.
•
3. In a gas lanp having a closed bowl, a circularly bent horizontal or approxi-
mately horizontal pipe carrying two or more burners arranged to project towards
the centre of the lamp flame that present a broad or extended surface towards a
reflector that is arranged independently of and above the burners and has an air
supply opening or openings in its lower side, or part, the said circularly bent pipe
being carried by a gas supply pipe that is separate from the reflector and is hinged
or pivoted to the main gas supply pipe so that it and the attached circularly
bent pipe and burners can be swung in and out of the lamp bowl, substantially as
described.
'

page_text: 4. The improved overhead gas lamps constructed substantially as hereinbefore
described with reference respectively to and shown in Figs. 1 to 4 inclusive, or in
Figs. 5 to 7 inclusive of the accompanying drawings, whether or not the air supply
opening 10 be of concave-convex, triangular or other equivalent shape, and whether
or not the raised central portion of the reflector be provided with a single central
exit opening or with a row of exit openings as set forth.
5. A gas lamp reflector having a central raised portion provided with one or
more exit openings for hot gases, and a hollow outer portion forming an air supply
chamber 5 having its inlet and outlet openings 9 and 10 out of line with each
other, the latter being of comparatively large size as set forth and being located in
the lower outer portion of the reflector, substantially as described.
6. In an overhead gas lamp of the kind herein referred to, a combined reflector,.
annular air chamber and chimney, the reflector having in its outer portion a
comparatively large air outlet opening or openings such as 10 communicating with
the annular air chamber, and a raised central portion having an exit opening or
openings for hot gases, and the air chamber having its air inlet or inlets arranged
out of line with the air outlet opening or openings, substantially as hereinbefore
described with reference to the several examples illustrated in Figs. 1 to 4
inclusive;
in Figs. 5, 6, and 7, and in Figs. 8, 9 and 10 of the drawings.
annexed.
7. The modified construction of combined reflector, air chamber and chimney
shown in Figs. 11 and 12 wherein the air chamber is provided with a single air
outlet opening 1t of annular shape arranged concentrically about the axis of the
lamp, whether or not a deflector 9 be provided for directing the issuing air
downwards.
Dated this 27th day of Febru1806
Dated this 27th
th day of February 1806
For the Applicants,
W. LLOYD WISE,
46 Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.