Improvements in Electric Incandescent Lamps.
Year: 1896

page_text: PROVISIONAL SPECIFICATION.
Improvements in Electric Incandescent Lamps.
GODFREY BAMBERG Chemist 33 Barcombe Avenue Streatham Hill S. W.
do hereby declare the nature of this invention to be as follows:-
The object of this invention is to lengthen the duration of the carbon filament.
in usual electric incandescent lamps, especially those intended for use on high
voltage circuits, by preventing as far as possible the breaking of the filament at or
near the junction with the platinum leading in wires, where there is the greatest
difference of potential, without altering the present shapes of lamps, or method of
external connection with the holder.
The breakage of the:filament can be prevented by causing the current to enter
at one end of the lamp, and leave the filament at the opposite and farthest removed
end, but this would be objectionable, since it would necessitate different.connections
to those already fitted and would detract from the appearance of the lamps.
In order to avoid this 1 fuse into the bottom of the lamp (where the usual
leading in wires are placed) one leading in wire, and a tube of glass or other
suitable insulating and non-combustible material containing the other leading in
wire & fused on to that wire at the bottom and which tube reaches to near the top
or nipple end of the lamp. This leading in wire reaches a little way out of the
top of the tube, which may be open at the top, so that both lamp and tube may be
exhausted together.
The filament may be a spiral around the tube but not touching the glass, and the
ends of the filament are joined one to the leading in wire at the bottom of the
lamp and the other to the wire reaching. out of the tube; obviously the tube.could
be further to one side of the lamp and the filament at or about the centre not
surrounding the tube, but the first way looks best. The bottom end of tube may
be slightly curved so as to bring the bottom further from the other leading in wire.
The two wires are joined externally in usual manner to the plates in collar of lamp
for connecting to holder.
By this method the parts of the filament at greatest difference of potential are
placed the farthest apart and the two leading wires are separated from each other
throughout. by the insulating tube and all usual connections and shapes are
maintained while the life of the lamp is greatly lengthened.
Dated this 18th day of June 1896.
GODFREY BAMBERG.

page_text: improvements in Electric Incandescent Lamps.
I, GODFREY BAMBERG, of 33 Barcombe Avenue, Streatham Hill. Loudon, 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 lengthen the duration of the carbon filament
in usual incandescent electric lamps, especially those intended for use on high
voltage circuits by preventing as far as possible the breaking of the filament at or
near the junction with the platinum leading-in wires, where there is the greatest
difference of potential, and without altering the present shapes of lamps or method
of external connection with the holder.
The breakage of the filament can be prevented by causing the current to enter
at one end of the lamp and leave the filament at the opposite and farthest removed
end, but this would be objectionable since it would necessitate different connections
to those already fitted and would detract from the appearance of the lamps.
The manner in which I carry my invention into practice will be readily understood
upon referring to the accompanying sheet of drawings in which Figures 1, 2, and 3
illustrate three methods of accomplishing the end desired in all of which I fuse
into the bottom of the lamp A oue of the usual leading-in wires B, the other
leading-in wire C being carried through a tube of glass D or other suitable
insulating and non-combustible material which is fused on to the wire C and to the
bottom of the lamp to hermetically seal the globe E.
The tube D is of sufficient length to reach near the top or nipple end of the
globe E and is open ended so that both the globe and the tube may be exhausted
together. The leading-in wire C projects out of the top of the tube D (preferably
at right angles) for connection to the filament F which may be arranged spirally
around the tube D but not touching it, said tube occupying a central vertical
position in the manner illustrated in Figure 1. The bottom end of the filament F
is connected to the other leading-in wire B in the ordinary manner. Or the tube D
instead of being straight may be slightly curved at the bottom as indicated at
Figure 2 whereby the leading-in wires B and C are situated further apart from
each other than is the case in the first example. Or instead of the filament F
surrounding the tube D, this latter may be curved to pass on one side in the manner
shown in Figure 3, the essential feature in all cases being to arrange the ends of
the filament as far apart, as possible and at the same time retain the leading-in wires
in their position for external connection in the usual manner to the plates in the
collar of the lamp for connection to the holder.
By this method therefore the parts of the filament at greatest difference of
potential are placed the farthest apart, and the two leading-in wires B, C, are
separated from each other and the wire C from the filament F throughout. by the
insulating tube, all the usual external connections and fittings are retained while
the life of the lamp is greatly lengthened especially those having filaments of a
high resistance by reason of less strain being put upon them tending to break them
away from the wires to which they are fused as is the case in ordinary lamps, and
moreover by the ends at greatest potential being so widely separated any
detrimental sparking, short circuiting bombardment, or flashing is prevented.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed I declare that what I
claim is
1. The improvements in incandescent electric lamps, consisting of an insulating

page_text: and incombustible tube fused to one leading-in wire and to the base of the lamp,
said tube projecting inwardly therefrom and enclosing a conducting wire for
connection to one end of the filament, said end of the filament being as far removed
as possible from its opposite end which is connected to the other leading-in wire,
which together with the first leading-in wire is connected in the usual manner to
the ordinary lamp base for connection to the holder, all as and for the purposes
described and substantially as shown in the drawings.
2. In an incandescent electric lamp, the insulating and noncombustible tube D
upstanding from the base of the lamp, conducting wire C within the tube and
projecting beyond the inner end of the tube arranged in the manner and for the
purpose described and shown in Figures 1, 2, and 3 of the annexed drawings.
2007
H. GARDNER,
Patent Agent, 166 Fleet Street, London,
Agent for the said Godfrey Bamberg.