IMPROVE- MENTS IN GAS LAMPS
Year: 1884

page_text: I FRANCIS HERBERT WENHAM of 238 Goldhawk Road Shepherds Bush
Middlesex Engineer do hereby declare the nature of said invention for "IMPROVE-
MENTS IN GAS LAMPS" to be as follows:-
My present Invention has reference to the class of Gas Lamp described in the
Specification of former Letters Patent No 4109 granted to me as of the 25th of
August 1882-According to my present Invention I provide an arrangement
whereby the gas is led downwards through a pipe to an Argand or equivalent
burner enclosed in a glass as in my said former Specification-The cover of the
Lamp has an extension above on the top of which is fitted or formed a ring or
surrounding piece having a series of hollow arms or air passages leading into a
central box or short Cylinder with a downward projecting rim dipping into a
trough or channel forming the head of the internal chamber or heater-In order to
make the connection air tight this channel is filled with Asbestos or porous fireclay
or other nonconducting material packed round the rim preventing transfer of heat
from the metal of the inner heating chamber to that of the air passages above.
Around the internal chamber fins or strips of metal are attached preferably in a
spiral direction. Enclosing these is à tube or sheath bell mouthed or flanged
at the top so as to close the upper part of the space between itself and the
extension of the cover. The lower end of this sheath carries the plate or reflector
beneath the cover of the lamp. The inner chamber sheath and Reflector are
preferably connected together and supported in place entirely by the central pipe
which is screwed through a boss connected by arms to the central chamber and
thus all other metallic connections with the outer casing of the lamp are avoided
and the heat of this part is further retained by the nonconducting packing at the
Lead of the heating chamber and outward radiation is retarded by the dead air
space between the sheath on the fins and the cylindrical extension of the cover.
Between the outer side of the burner and the nozzle or lower end of the inner
chamber or in the inner chamber an annulus of gauze or perforated or divided
metal referred to in my former Patent may be used but this annulus may consist
of strips of metal forming a series of channels preferably set in an inclined direction
so that the down current of air impinges across the stream of gas issuing from the
buiner. In the central passage of the burner similar arrangements may be used

page_text: and when it consists of slanting strips they may slant in the same direction as the
outer strips thus giving a twist to the inner current also-The space between the
button deflector or disc and the burner may be surrounded with a ferrule or ring
having lipped or oblique orifices in its circumference so that the issuing air
takes the same cross direction as that given by the strips within and without
the burner but in this case it is preferable to make some holes below through the
button déflector or disc.
A perforated box or basket covering the interior passage through the burner
would be the equivalent of this arrangement-If this arrangement be not used the
button deflector or disc may be perforated and be either flat convex or concave as
the construction and uses of the lamp may require.

page_text: I FRANCIS HERBERT WENHAM of N° 238 Goldhawk Road Shepherds Bush in
the County of Middlesex Engineer do hereby declare the nature of my invention
for "IMPROVEMENTS IN GAS LAMPS" and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
My present Invention has reference to the class of Gas Lamps described in the
Specification of former Letters Patent No 4109 granted to me as of the 28th of
August 1882 In a lamp constructed according to my present Invention I provido
an arrangement wherein the gas is led down through a pipe to an argand or
equivalent burner a enclosed in a glass b as described in my said former Specifi-
cation The cover of the Lamp glass has a ring or extension c above on the top
of which is fitted or formed a ring or surrounding piece d having a series of hollow
arms or air passages e leading into a central box or short Cylinder with a down-
ward projecting rim f dipping into a trough or channel g forming the head of the
internal chamber or heater h.-In order to make the connection air-tight and to
conduct as little heat as possible to the exterior of the lamp this Channel is filled
with asbestos or porous fire clay or other non-conducting or refractory material
packed round the rim so as to prevent transfer of heat from the metal of the inner
heating chamber h to that of the rim f above. A non-conducting or refractory
packing such for example as a strip of asbestos cloth may also be inserted.
between the junction of the extension ċ or top of the cover and the outer ring d
for the purpose of still further preventing conduction of heat to the exterior of
the lamp.
Around the oxterior of the Chamber h pins or strips of metal i may be attached
they being preferably disposed in a helical direction.
Surrounding the Chamber h so as to enclose a space therearound is a tube or
sheath preferably bell mouthed or flanged at the top as shewn at ³ so as to close
the upper part of the space between itself and the extension c of the cover.-The
lower end of this sheath j carries the plate or reflector & beneath the cover of the
lamp-The heat of the lamp is retained by the non conducting packing at the head
of the heating chamber, and outward radiation is retarded by the dead air space
between the sheath; and the extension c of the cover-Between the outer side of
the Burner a and the nozzle or lower end of the heating chamber h an annulus of
gauze or perforated or divided metal may be used as described in the Specification
of
my said former Patent but this annulus may consist of strips of metal forming
a series of channels preferably set in an inclined direction so that the down current
of air for feeding the flame may impinge against the stream of gas issuing from
the burner a. In the central passage through the burner and also as described in
the Specification of my said former Patent similar gauze or perforated metal may
be placed as at a² and these also may consist of slanting strips inclining in the same
direction as the outer strips thus giving a twist to the inner current also.-In
place of these two perforated portions and a² one piece of gauze or equivalent
perforated or divided metal may extend across the Chamber above the burner a.-

page_text: "
The space between the button deflector or disc m and the burner may be surrounded
with a ferrule or ring having orifices in its circumference which may be furnished
with lipped or oblique webs so that the issuing air takes the same cross direction
as that given by the aforesaid strips within and without the burner, or the button
dise or deflector m may itself be perforated with a hole or holes and it may be
either flat or convex or of other suitable figure.
This perforated button disc or deflector may be used in combination with
the ferrule or ring before mentioned-A perforated box or basket covering
the interior passage through the burner would be the equivalent of this
arrangement.
Hot air descends through the button or deflector thus constituted, and rising
again in the direction shown by the arrows a serves as an additional air supply
to the outer margin of the flame.
In ring or argand burners of large diameter a button or deflector having only
one perforation in the centre may be used as shewn in section in Figure 2 where a
is the burner and n a central tube or hollow stem supporting the button or
deflector m-Air is admitted by the perforations at the top of the hollow stem n
and passes through the central perforation or orifice in the button or deflector m.-
The drawing shews combined with this arrangement a tube p conveying gas down
to what is known as a "spur burner" q having gas orifices round its circumference
so that the blank or dark space in the centre of the outer ring burner may also
contain a gas flame ? below the top one s as shewn in the drawings..
The arrows in the drawings illustrate the course of the currents of air to and
from the burner.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed I declare that what
I claim is
First In gas lamps of the kind hereinbefore referred to the combination of an
air heating chamber forming a passage for air to the burner and a sheath sur-
rounding the said chamber and an upward extension of the lamp ca-ing or a ring
surrounding the said sheath with spaces between each and passages or tubes for
the inlet of air substantially as herein before described and illustrated in the
accompanying drawings.
Second-In gas lamps of the kind hereinbefore referred to the combination of
an air heating chamber forming a passage for air to the burner, a sheath enclosing
a space around the said chamber passages or tubes for leading the air into the said
chamber and a ring or an extension of the lamp casing enclosing a space around
the said sheath, the junction between the said chamber and the said air passages
or tubes, or between the ring or extension of the casing and the said air passages
or tubes, or both such junctions being effected by the intervention of a non-
conducting or refractory material substantially as hereinbefore described and
illustrated in the accompanying drawings.
Third-In lamps of the kind herein before referred to the use beneath the
burner of a perforated button disc or deflector in combination or not with an
additional burner substantially as and for the purpose herein before described.
Fourth: The arrangement and combination of parts constituting the gas lamp
substantially as herein before described.