Improvements in Gas Lamps.
Year: 1897

page_text: Date of Application, 7th May, 1897-Accepted, 12th June, 1897
COMPLETE SPECIFICATION.
Improvements in Gas Lamps.
We, TпочAS COOPER JOHN THOMAS, Engineer, and WILLIAM MUDD STILL,
Manufacturer, both of 24 Charles Street, Hatton Garden, in the City of London,
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 relates to gas lamps of the kind described in the Specifications of
former Letters Patent, No. 435 of 1895 granted to one of us, and No. 22726 of
1895 granted to both of us, according to which a gas lamp having a closed bowl
or chamber is provided 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, the arrangement being such that the entering air will impingo
upon the upper surface of the flame extending from the burner, or from each
burner, and impart a curved form to such flame and direct it towards the gas exit
opening or openings leading to the chimney.
In the Pintsch and Pope lamps shown in our said Specification No. 22726 of
1895, air for supporting combustion passes into the upper part of the movable lamp
head or cover through an annular air inlet opening below which is provided a
perforated plate that acts as a baffle and causes the air in conjunction with the
peculiar forms of reflectors shown in the said specification to flow in a gentle and
uniform manner to the flames extending from the burnors whereby a very efficient
illuminating effect is obtained.
In applying burners and reflectors constructed and arranged in the manner
described in the said former Specification No. 22726 of 1895 to the lamp bodies or
casings of certain other forms of existing railway carriage roof gas lamp, such as
those used on the Midland Railway, in which air enters the lamp between the lamp
head and lamp body, is free to diffuse itself without check through the interior of
the latter, and passes unimpeded direct onto and through the top of the body of the
reflector, considerable difficulty has been experienced in causing the flame or flames
from the burner or burners to burn in a steady manner with the maximum
illuminating effect. This invention has reference to means whereby the above
mentioned disadvantage can be obviated in a simple and effective manner, as WO
shall now proceed to explain by reference to the accompanying drawings wherein
Fig. 1 shows, in vertical section, a railway carriage gas lamp of the kind hereinabove
referred to, the lamp body and lamp head being of the kind now commonly used
on the Midland Railway but adapted according to this invention for use with a
reflector and burners arranged as hereinabove set forth.
1 are the gas burners carried by the inwardly turned ends 2 of a bent gas supply
pipe 3,3 pivoted at 6 to a main gas pipe, the said burners being arranged below
triangular shaped openings 10 in the lower side of a reflector 5 that is formed with an
air chamber 5 to which air is admitted through opening (not shown) arranged in th
top of the chamber away from the said air outlet openings 10, all as described and
shown in our said former Specification No. 22726 of 1895, a perforated baffle plate 9"
of inverted conical shape being usually secured to the top of the reflector.
The lamp body shown comprises two cylinders 7, 7* arranged concentrically and

page_text: secured by flanges 7, 7B respectively to the upper and lower sides of a railway
carriage roof A. The outer cylinder has hinged theret at one side, a lamp head 7ª
the lower sido 7 of which is unperforated and arranged to rest upon the top of the
cylinder 7 and leave a narrow annular passage 11 between itself and the top of the
inner cylinder 7* through which air entering the space 7° between the two cylinders
by diametrically arranged notches or recesses 7" and by perforations 7° in the outer
cylinder 7 can freely enter the interior of the lamp body and pass to the reflector 5
below.
Now in order that reflectors 5 of the kind shown and described in our said
former specification and in Fig. 1 of the accompanying drawing, and in which air
enters the air supply chamber 55 by passing vertically downward through openings in
the top of the reflector, may be efficiently use with lamp bodies and lamp heads of
the kind described and shown, we combine with the movable lamp head 7, an annular
depending curtain or baffle plate 12 which is secured to the lower side 7 of the lamp
head opposite the air passage 11 so that air flowing rapidly through such passage will
impinge against the said curtain or baffle plate with the result that it will become
broken up and its velocity checked to such an extent as to enable the lamp to burn in
an efficient manner with reflectors of the construction above referred to. The curtain
or baffle plate 12 may be perforated, as shown at the right hand side of Fig. 1, so
as to aid in breaking up the entering air.
To enable lamp bodies and lamp heads of the kind shown and described with
reference to Fig. 1 to be utilized without making any alterations or additions
whatever thereto to enable them to be used with reflectors and burners constructed
and arranged according to the former inventions herein before referred to, we provide,
according to this invention, modified constructions of such reflectors which are
specially adapted to bafile the current of air supplied to the interior of the lamp body
or casing to such an extent as to prevent it interfering with the proper burning of
the issuing gas, which, as usual, is of the kind known as oil gas.
Fig. 2 is a vertical section showing a gas lamp of the kind herein referred to having
a lamp body and head of the kind mentioned, and a modified construction of reflector
to enable said lamp body and head to be utilized without alteration.
Fig. 3 shows the reflector partly in plan and partly in section on the line of
Fig. 2.
In this arrangement the reflector is substantially similar in construction to that
shown in Figs. 8, 9, and 10 of the drawings filed with our former Specification
No. 22726 of 1895, the reflector proper 5 being of spun or stamped metal having a
raised central portion 5 with central exit opening and secured to a dished and
flanged top plate 9 which is cast in one with the chimney 8 and forms with the
reflector proper, an air chamber 5 to which air is admitted through air openings 9"
(Fig. 3) arranged in the plate 9 at about right angles to the air exit openings 10.
To more effectually baffle the air flowing into the reflector, there is secured
according to this invention to the top of the reflector, as by screws 13 and distance
pieces 14, an annular dished baffle plate 15, the inner periphery 15" of which fits
around the base of the chimney 8, and the outer periphery 15 of which is held away
from the outwardly flanged upper part 9 of the reflector so as to form therewith a
narrow annular air inlet opening 16.
By this construction, air descending the interior of the lamp body will mainly
impinge upon the top of the unperforated baffle plate 15 whereby its downward force
will, to a large extent, be destroyed; it will then pass around the outer periphery 15
of the said plate and flow horizontally through the annular opening 16 so as to abut
against the dished portion of the plate, after which it will flow downward into the
annular chamber 50 formed between the plate 9 and the baffle plate 15, whence it will
pass in a steady stream through the openings 9, chamber 5, and openings 10 to the
flames extending from the burners 1.
Fig. 4 shows partly in side elevation and partly in vertical section, and Fig. 5 partly
in plan and partly in horizontal section, a modified construction of the reflector,
according to which the dished baffle plate 15 is provided with a central upward tubular

page_text: xtension 15° arranged to surround the chimney 8 and the upper end of which, when
use, is below the chimney 7' carried by the lamp head. By this construction the
urrent of air entering the chamber 5 as described with reference to Figs. 2 and 3,
vill become divided, part entering the chamber 5b and flowing to the flames as before,
nd part escaping upward through the annular passage 15.
Fig. 6 is a similar view to Fig. 4, showing a inodification wherein the dished bafflo
plate 15 is of double conical shape, its outer portion 15 being secured flat against the
Hange 9 of the plate 9, whilst its inner conical portion 15 is arranged to surround
the chimney S and form therewith a narrow annular air inlet passage 16. In this
case the air descending the body of the lamp mainly impinges upon the top of the
dished plate and then rises and passes over the conical part 15" descending the
passage 16 to the chamber 5 and thence passing as before to the chamber 5 and
lamp Hames.
Figs. 7 and 8 show a modification in which the annular baffle plate 15 is of flat form
secured at its outer edge to the flanged plate 9 so as to form therewith an annular
air passage 16 as in Figs. 2 to 5, the inner periphery of the plate fitting the chimney.
Over each of the series of perforations 9", which are usually formed in a plate secured
over a slot in the plate 9, is secured a sheet metal cap, box or chamber 17 provided
at the inner side with a perforated vertical baffle plate 17 through which air entering
the chamber 5° must pass before it can pass through the perforations 9 to the
chamber 5, thereby ensuring a steady flow of air to the burner flames. Each cap,
box or chamber 17 with perforated baffle plate 17 may be secured to or be formed
partly by the top baffle plate 15, in which case instead of a single annular air way 16,
there would be two horizontal air ways between the cap boxes or chambers. Such
baffling devices may with advantage be applied in connection with the reflectors shown
in Figs. 2 to 6 inclusive, and also in those shown in our said former Specification
No. 22726 of 1895.
To further assist in ensuring a steady flow of air to the outlet openings 10 of
reflectors of the kind hereinbefore described, and also those described in our said
former Specification No. 22726 of 1895, there may be provided in the chamber 5 on
each side of each of said outlet openings, a series of vertical baffling devices which may
be in the form of pins 18, as shown in half plan in Fig. 9, or of plates 18ª, as shown
in Fig. 10. These baffling devices may be cast in one with the dished plate 9.
The holes for admitting air to the lamp bowl for the purpose inter alia of keeping it
cool, may be formed in the reflector proper 5, as shown at 19, but in the constructions
of reflectors shown in Figs. 2 and 3; 4 and 5; and 7 and 8 it is preferred to form
them in the flange 9 of the dished plate 9 below the baffle plate 15, as shown at 19°
in these figures.
Reflectors of the kind shown in Figs. 2 to 8 inclusive, although specially suitable
for use with lamp bodies and heads of the kind shown in Fig. 2, are also suitable for
use with other lamp bodies and heads, such for examples as those shown in our said
former Specification No. 22726 of 1895.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
1. Providing a lamp body and head of the kind hereinbefore described and shown
in Fig. i for use with reflectors and burners of the kind referred to, with a depending
curtain or baffle plate 12 substantially as described and shown for the purpose
specified.
2. In a gas lamp of the kind herein referred to, the combination with a lamp body
and head of the kind shown in Fig. 2, of a reflector of the kind herein mentioned
provided at its upper side with a non-perforated baflle plate 15 constructed and
arranged substantially as herein before described with reference to the several
examples shown in Figs. 2 to 8 inclusive of the accompanying drawings for the
purposes specified.
3. A gas lamp reflector of the kind herein referred to having air chambers 5 and 5°

page_text: and one or more series of perforations 9 connecting the two, and above said
perforations, or above each sories of such perforations, a cap box or chamber 17
with perforated vertical baffle plate 17 through which air must pass before it can
pass through the perforations 9, substantially as described and shown for the purpose
specified.
4. A gas-lamp reflector of the kind herein referred to having on each side of each
of its air outlet openings 10, a series of baffling devices such as pins cr plates as
hereinbefore described with reference to Figs. 9 and 10.
5. Gas lamp reflectors of the kind herein referred to having dished baffle plates 15
constructed and arranged as hereinbefore described with reference respectively to and
shown in Figs. 2 and 3; in Figs. 4 and 5; and in Fig. 6 of the drawings annexed,
with or without baffling devices of the kind shown in and described with reference to
Figs. 9 and 10.
6. A gas lamp reflector of the kind herein referred to having a baffling plate and
bafting devices constructed and arranged as herein before described with reference to
and shown in 7 and 8 of the drawings annexed.
Dated this 7th day of May 1897.
For the Applicants,
W. LLOYD WISE,
46 Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.