Improvements in Incandescent Gas Lamps.
Year: 1896

page_text: Date of Application, 2nd Apr., 1890
Complete Specification Left, 31st Dec., 1896-Accepted, 13th Mar., 1897
Date of Application,
Apr., 1890
Complete Specification Left, 31st Dec., 1896-Accepted, 13th Mar., 1897
PROVISIONAL SPECIFICATION.
Improvements in Incandescent Gas Lamps.
I, JOHN FREDERICK DUKE of 160 Rosendale Road, West Dulwich in the County
of London, Chemist, do hereby declare the nature of this invention to be as
follows:-
The object of this invention is to prevent the shattering effects upon the mantle
of incandescent gas lamps due to the explosion when the lamps are ignited and more
particularly when the lamps are ignited by means of a match or of an automatic
igniter of the kind described in my Specification No. 969 of 1895 and not by a
permanently lighted gas jet. The shattering effects referred to are due to the use of
what is generally known as the "lighting back plate" that is to say the plate usually
placed on the burner to prevent the flame which blows down when the lighting takes
place from approaching the air inlets to the atmospheric burner. This plate by
obstructing the explosion in a downward direction causes a recoil in the chimney
just where the mantle is placed with the result that the mantle is shattered.
Now according to my invention I cover the air inlets above referred to internally-
with wire gauze and I dispense with the lighting back plate. Consequently while
there is no obstruction to the downwards effects of the explosion the light is prevented
by the wire gauze from passing through the air holes.
Dated this 2nd day of April 1896.
J. C. MEWBURN & ELLIS,
55 and 56 Chancery Lane, London, Chartered Patent Agents.
Improvements in Incandescent Gas Lamps.
I, JOHN FREDERICK DUKE of 160 Rosendale Road, West Dulwich in the County
of London, Chemist, 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:-
The object of this invention is to prevent the shattering effects upon the mantle
of incandescent gas lamps due to the explosion when the lamps are ignited and more
particularly when the lamps are ignited by means of a match or of an automatic
igniter of the kind described in my Specification No. 969 of 1895 and not by a
permanently lighted gas jet. The shattering effects referred to are due to the use of
what is generally known as the "lighting back plate" that is to say the plate usually
placed on the burner to prevent the flame which blows down when the lighting takes
place from approaching the air inlets to the atmospheric burner. This plate by
obstructing the explosion in a downward direction causes a recoil in the chimney
just where the mantle is placed with the result that the mantle is shattered.
Now according to my invention I cover the air inlets above referred to with wire
gauze and I dispense with the lighting back plate. Consequently while there is no

page_text: obstruction to the downward effects of the explosion the light is prevented by the
wire gauze from passing through the air holes.
The wire gauze may be fitted either internally or externally but I have found in
practice that there is an advantage in fitting it externally because it is liable in course
of time to get somewhat covered with dust and this can be more readily removed
when the gauze is outside.
Figure 1 is an elevation partly sectional of so much of an incandescent gas lamp
as is necessary to illustrate my invention. Figure 2 is a section on the line 2-2 of
Figure 1. In these figures the wire gauze is shown as fitted internally. Figure 3
is an elevation and Figure 4 a section on the line 4-4 of Figure 3 of a lamp in
which the gauze is outside.
The same letters of reference indicate the same parts in all the figures.
a is the perforated nozzle through which the gas passes before mixing with the
air. bh are the air inlets in the cylinder c. d is the chamber in which the gas and
air meet and mix. e is the wire gauze cover to the air inlets bb, it is preferably a
single piece of gauze bent into cylindrical form and fitted around the cylinder either
inside as in Figures 1 and 2 or outside as in Figures 3 and 4. The inlets bb should
be made of somewhat larger area than usual so as to compensate for the diminution
in the passage way caused by the gauze e.
The ordinary lighting back plate" which 1 now dispense with is indicated in
dots at.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, 1 declare that what I
claim is :-
Covering the air inlets of incandescent gas lamps with wire gauze, substantially as
and for the purpose hereinbefore described.
Dated this 31st day of December 1896.
J. C. MEWBURN & ELLIS,
55 and 56 Chancery Lane, London, Chartered Patent Agents.