Improvements in Electric Incandescent Lamps.
Year: 1899

page_text: Date of Application, 4th July, 1899-Accepted; 20th Jan., 1900
774
COMPLETE SPECIFICATION.
Improvements in Electric Incandescent Lamps.
I, JACOB ATHERTON, of 11, Charing Cross Road, London, in the County: of
Middlesex, Electrical 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 any by the following statement:-
This invention relates to improvements in electric incandescent lamps and has
for its chief object to construct a lamp which can be repaired in a very simple.
and inexpensive manner after the filaments become broken. A further object is
to provide the lamp with a cap or base which can be readily removed from and
effectually secured to the lamp without the use of cement, and my present inven-
tion more especially consists in improvements in connection with said cap.
According to my invention the lamp bulb is formed with an elongated tubular
neck which is blown in one with the bulb and the said neck can be readily cut or.
divided, by means of a red hot wire or otherwise, to enable a broken filament to
be removed and replaced by a fresh one, the detached neck (or part of the neck).
being afterwards fused on to the bulb. It is of great importance that an easily
removable cap or base should be provided on the lamp bulb of this construction,
as if the ordinary cemented caps were used there would be great danger of the
connections or joints being destroyed, and the cement also being injured, by the
lieat employed in rejoining the neck of the bulb.
In the construction of the lamp the ordinary filament is attached (in any
convenient or well known manner) to elongated terminal wires connected to the
above mentioned easily removable cap, such elongated wires being necessary
owing to the length of the tubular neck on the lamp bulb. When the lamp is
required to be renewed the elongated neck is cut or divided as above mentioned
and a new filament already attached to two short connecting pieces or wires
(such filaments and connecting wires being kept in stock for the purpose of
renewals) is substituted for the broken one which is disconnected from the
terminal wires, the short connecting wires on the new filament being fused on
to the existing terminal wires in the disconnected neck of the lamp bulb, the
bulb being then fused on to the neck and exhausted in the usual manner, when
the lamp will again be ready for use.
In order that my invention may be clearly understood and readily carried into
effect I will describe it with reference to the accompanying drawings in which,
Figure 1 is an elevation of a lamp according to my present invention, with
the cap or base removed.
Figure 2 is a view showing my special form of cap attached to the tubular
neck of the lamp, the cap in this figure being adapted to fit in the lamp holder
or socket by means of the usual bayonet joint.
Figure 3 is a sectional plan on line A-A Figure 2.
Figure 4 shows the cap adapted to be screwed into the lamp holder or socket.
Figure 5 is a view of my special cap detached from the lamp, and Figure
is an end view of same showing the wire terminals.
Figure 7 shows the elongated neck detached from the lamp bulb, and the
renewal filament with short connecting wires.

page_text: The same letters refer to the same parts in the several figures.
a (Fig. 1) is the lamp bulb provided with the tubular neck a¹. The main
object in making the lamp in this way is that owing to the length of the neck a¹
and its comparatively small diameter it can be readily separated or cracked, by
means of a red hot wire or otherwise, and readily refused to the bulb after the
new filament has been inserted, without injuring the terminal wires where they
pass through the glass. bb are the terminal wires and c is the filament. The
top or end of the elongated neck a¹ is formed with recesses or indentations e el on
opposite sides thereof, also a bead or shoulder f.. The cap g (Fig. 2) has slots
or openings on opposite sides thereof which slots correspond with the
recesses e e respectively in the elongated neck a'. h, is a wire ring which
fastens the cap to the lamp said wire taking in the slcts in the cap and
in the recesses e el in the elongated neck a, the inner end of cap 9 resting on
the shoulder f. It is obvious that the wire or ring can be readily removed
so that the cap y can be taken off the lamp and it can be as easily replaced.
jare the terminals of the cap g and the insulating material in which said:
terminals are set.
In Figure 4, are the short connecting wires to which the renewal filament
is attached.
Assuming that the filament of the lamp is broken and that it is desired to
replace it by a new one it is only necessary to crack the glass around the tubular
part or neck of the lamp at a suitable point such as a (Fig. 1); then withdraw
the damaged filament, cutting, the wires bb, reinsert the fresh filament with
short connecting wires attached, joining said short connecting wires (kk', Fig. 4).
to the existing terminal wires bb.in the neck a', then refuse the bulb a on to
said neck. The lamp can be exhausted in any convenient manner and will
then be ready for use again. If any damage has occurred to the connections at
the closed end of the neck a' the cap can be readily removed, the connections
made good and the cap replaced again.
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
1. In electric incandescent lamps, the combination of a bulb having an elon-
gated neck with indentations (e el) in said neck, with a cap provided with slots
corresponding with said indentations and a wire or the like which holds said
cap in position, substantially as herein described' and as illustrated in the accom-
panying drawings.
2. A cap such as hereinbefore described for use with incandescent electric
lamps other than that described herein.
Dated this 4th day of July 1899.
JOHN P. O'DONNELL,
Agent for said Applicant.