Improvements connected with Street or Outside Gas Lamps, and in the Arrangement of Unprotected Incandescent Mantles therein.
Year: 1897

page_text: Improvements connected with Street or Outside Gas Lamps, and in
the Arrangement of Unprotected Incandescent Mantles therein.
I, JOHN HOLMES SHELDRAKE, of Fingaske, Chatsworth Road, West Norwood,
London, Gas Engineer, do hereby declare the nature of this invention to be as
follows:-
-
This invention has for object;
1. A novel construction of lantern for an outside or street gas lamp, and
2. A method of arranging an incandescent mantle and burner therein, in order
that said incandescent mantle may be used without being enclosed in a tube or
chimney.
For the purpose of my invention, I make the body of a lantern of a street or
outside gas lamp in the usual manner and fit an inverted cone reflector within the
upper part.
The central part of said inverted cone has a tube, this rising well up within a
shell and surmounted by guard cones to protect the inner tube from the action of
the wind and to prevent undue suction.
I carry the burner supply pipe well up in the body of the lantern and provide it
with the usual atmospheric air holes in a swelling for the proper admixture of
air and gas within a short length of tubing, this carrying the burner proper and
the mantle, the top of which just enters the opening (or near thereto) of the central
tube.
Surrounding the burner is another cone, the top of which is of equal diameter, or
nearly so, to that of the central upper tube which for the purposes of this invention
carries off the products of combustion.
The cone surrounding the burner is of such depth that it directs the air entering
from the lower part of the lantern to the outside of the mantle for effecting perfect
combustion and for enhancing the brilliancy of the incandescent flame, the mantle
being left unprotected.
The angle of the reflector cone is such that it takes up and diffuses the light well
down under the lamp in addition to spreading it a considerable distance around
whereby the invention is specially applicable for street or outside gas lamps not
hitherto attainable by incandescent mantles.
100%
H. GARDNER,
Patent Agent, 166, Fleet Street, London,
Agent for the said John Holmes Sheldrake.

page_text: Improvements connected with Street or Outside Gas Lamps, and in
the Arrangement of Unprotected Incandescent Mantles therein.
I, JOHN HOLMES SHIELDRAKE, of Fingaske, Chatsworth Road, West Norwood,
London, Gas Engineer, 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 for object
1. A novel means for improving the conditions of incandescent mantles when
used for outside or street gas lamps, and
2. A method of gathering air to the mantle and burner of an incandescent street
or outside lamp, in order that said incandescent mantle may be used without being
enclosed in a tube or chimney.
For the purpose of my invention and as shown on the annexed drawings (an
ordinary street lantern and a wall lantern, Figures 1 and 2 respectively), I make
the body A of the lantern of a street or outside gas lamp in the usual manner as
shown and fit an inverted cone reflector B within the upper part. Above the
central part of said inverted cone is a tube C rising well up within the upper
shell D and surmounted by guard cones E to protect the inner tube C from the
action of a down draught.
Figure 3 represents a detachable or affixable incandescent mantle and burner
with my invention applied, for insertion into an ordinary street or outside lantern
by simply removing an existing nipple and screwing it to the burner socket.
I carry the burner supply pipe F well up in the body of the lantern and provide
it with the usual atmospheric air holes in a swelling G for the proper admixture
of air and gas within a short length of tubing H this carrying the burner proper
and the incandescent mantle I the top of which just enters (or near thereto) the
opening of the central tube C.
Surrounding the burner is another cone J, the top of which is of equal diameter,
or nearly so, to that of the central upper tube C which for the purposes of this
invention carries off the products of combustion. The cone J (of glass or other
material, transparent or opaque) surrounding the burner is of such depth that it
directs the air entering from the lower part of the lantern A to the outside of the
mantle for effecting perfect combustion and for enhancing the brilliancy of the
incandescent flame, the mantle being left unprotected.
The angle of the reflector cone B is such that it takes up and diffuses the light
well down under the lamp in addition to spreading it a considerable distance
around whereby the invention is specially applicable for street or outside gas
lamps not hitherto attainable by incandescent mantles.
Any ordinary system of service tap K can be fitted to the supply pipe F but I
prefer the double lever L and chains as shown on the drawing, the lantern A being
on a lamp post M for ordinary street lighting or on an ornamental or other
bracket N for support from a wall.
I am aware that incandescent mantles have been proposed and have been used
for ordinary street lighting purposes and therefore make no claim to such use in
a broad sense but the features of my invention are the employment of a mantle
with its top just entering the flue tube C in conjunction with the cone J surround-
ing the burner for concentrating a soft or gentle current of fresh air to the out-
side of the mantle in an equal and regulated manner to enhance the brilliancy of
the flame and to prevent the top of the mantle becoming dull from an excess of air
impinging against it as at present and whereby not only is the mantle preserved
from sudden rushes of volumes of air which often congregate in the lantern and

page_text: besides
then as suddenly escape up the central tube C, but by reason of the shape and
proximity of the inverted reflector B the heat derived from the flame, rarifies the
air in the upper part of the lantern and renders it the better adapted for maintain-
ing the incandescence of the upper part of the mantle I;
which the usual rapid motion of the air from the entry at the bottom of
the lantern to the uptake C is checked or retarded by the volume of heated air
reserved in the space directly under the inverted cone reflector B, whereby the
flickering so noticable in the present incandescent street lighting becomes absorbed
and the incandescence more uniform, no particular part of the mantle being
affected.
The cone J by gathering the air centrally for up travel to the mantle I also offers
a medium for increasing the air supply to the apertures of the atmospheric burner
thereby increasing the luminosity of the mantle.
For railway station and other exposed draughty situations my inverted cone
reflector B and air concentrating cone J in conjunction will be of value in support-
ing the purity of the incandescent flame where from the swinging of the lamps due
to the wind and the consequent injury to the mantles, fractures of the mantles and
deadness of light will be entirely prevented.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed I declare that what I claim is:-
The improvement in street and like outside incandescent systems of lighting
whereby glass or talc chimney also glass bulbs are discontinued, as herein specified,
consisting of a cone J at the burner G to supply and concentrate air to the burner
and mantle I, in combination with the inverted reflector B and tube C having
rarefying action on air within the upper part of the lantern A, as and for the
purposes described.