Improvements in the Manufacture of Electric Incandescent Lamps.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Electric Incandescent Lamps.
I, ADOLPHE WIERRE, of 50, Rue Turenne, Paris, France, Manufacturer of
Electric Lighting Apparatus, do hereby declare the nature of this invention
to be as follows:
Incandescent electric lamps have hitherto usually been made by introducing
into a prepared bulb the filament previously cemented to the leading-in wires
fixed in a mass of glass which is then fused to the bulb after which the completed
bulb is again blown to test it and rectify any distortion. After the bulb has been
exhausted of air, two conductors are generally, for the sake of economy, soldered
to the leading-in wires and to the terminals of the lamp base after the latter has
been fixed to the bulb by plaster. It will be seen that a lamp thus made involves
numerous manipulations representing nearly the whole of its prime cost; more-
over it forms an indivisible whole which is rendered useless immediately the
filament becomes unserviceable.
The system of lamp and method of manufacture which forms the subject of the
present application for Letters Patent are designed to avoid these objections and
present, as compared with existing systems, the following advantages :-
(1) Reduction of hand labour in the manufacture;
(2) Utilization of those parts of a worn-out lamp which still remain service-
able;
(3) Reduction of the cost of manufacture and hence possibility of employing
economical filament lamps;
(4) Perfect adhesion between the bulb and its cap or base thus rendering it
impossible for the bulb to become disconnected when in use;
In order that the invention may be more readily understood I have illustrated
it by way of example in the accompanying drawing in which Figure 1 represents
a glass bulb, Figure 2 an exterior elevation, and Figure 3 a section on line 1-2
Figure 2, of the cap or base. Figure 4 shews a modified form of cap in which
the seat for the bulb is at d. is the bulb which may be made of flint or other
glass, opaline, or other material used for lamp bulbs, and may be of any suitable
form.
The neck (Figure 1) instead of being a tube of some centimetres in length,
as usual, is cut off close up to the shoulder of the bulb at c so as to present a
cylindrical section. The neck of the bulb thus prepared is suitably metallized
so as to render it capable of adhesion when metallic solder is used. This orifice

page_text: is such that it may fit easily in a cup of any suitable form of which the use is to
contain a certain quantity of solder. The cap may be fitted to the holder by means
of a bayonet joint, screw, or other means of fixing. This cap may be of moulded
glass, opaline, porcelain, earthenware, enamelled metal, etc. provided it be of
suitable form and give passage to the leading-in wires whilst remaining air-tight
and also furnish a metallized seat or cup for the neck of the bulb when metallic
solder is used.
In the example illustrated in Figure 2 the lamp is to be fixed by a
bayonet joint, the cap d being made of porcelain and the terminals, which also
serve as supports for the filament or filaments, being fixed at the moment of glaz-
ing the porcelain, and the metal holding cup e.
To produce a lamp on my system I proceed in the following manner:-I take
a bulb a provided with the usual exhausting tube and in the groove e of the
cap or at the bottom of the cap as the case may be I place some metallic
solder, preferably ordinary plumber's solder although any other kind of solder
may be employed. The filament is united by any suitable means to the terminals.
The whole, or more exactly the cap, d, is then brought to a temperature which will
permit of the fusion of the solder which after cooling will hold the whole in place
and ensure a perfectly air-tight joint.
When ceramic cement is used the method of procedure is much the same
except that the cap d is placed in a suitable oven and that instead of solder, a
few grains of enamel or highly fusible lead glaze would be placed around the
joint. It is necessary in this case to cool very slowly in order to avoid cracks
caused by too sudden cooling, and it is on account of this difficulty in the cooling
that metallic solder is preferred.
It now only remains to exhaust the air and seal the bulb at the blow-pipe, to
have a lamp ready for use.
I will now describe how, when the lamp becomes unserviceable by the wearing
out of the filament for example, I am enabled to obtain a new lamp at a minimum
expense. After first slightly grinding off the point of sealing so as to admit air
to the bulb, I heat the cap to a suitable temperature for the purpose of separating
it from the bulb. The bulb is then again provided with an exhausting tube and
if necessary all traces of carbon which may have become deposited within it are
removed. By then repeating the same operations as previously described, an
absolutely new lamp is obtained at the cost of a new filament, whereas a lamp
made in the ordinary way herein referred to would be entirely useless in the
event of the filament becoming unserviceable.
Dated this 22nd day of November 1897
A. M. & WM. CLARK,
Chartered Patent Agents, 53, Chancery Lane, London.
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Electric Incandescent Lamps.
I, ADOLPHE WIERRE, of 50, Rue Turenne, Paris, France, Manufacturer of
Electric Lighting Apparatus, 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:-
Incandescent electric lamps have hitherto usually been made by introducing
into a prepared bulb the filament previously cemented to the leading-in wires
fixed in a mass of glass which is then fused to the bulb after which the completed
bulb is again blown to test it and rectify any distortion. After the bulb has been

page_text: exhausted of air, two conductors are generally, for the sake of economy, soldered
to the leading-in wires and to the terminals of the lamp base after the latter has
been fixed to the bulb by plaster. It will be seen that a lamp thus made involves
numerous manipulations representing nearly the whole of its prime cost; more-
over it forms an indivisible whole which is rendered useless immediately the
filament becomes unserviceable.
The system of lamp and method of manufacture which forms the subject of the
present application for Letters Patent are designed to avoid these objections and
present, as compared with existing systems, the following advantages:-
(1) Reduction of hand labour in the manufacture;
(2) Utilization of those parts of a worn-out lamp which still remain service-
able;
(3) Reduction of the cost of manufacture and hence the possibility of employ-
ing economical filament lamps;
(4) Perfect adhesion between the bulb and its cap or base thus rendering it
impossible for the bulb to become disconnected when in use;
In order that the invention may be more readily understood I have illustrated
it by way of example in the drawing accompanying my Provisional Specification
in which Figure 1 represents a glass bulb, Figure 2 an exterior elevation, and
Figure 3 a section on line 1-2 Figure 2, of the cap or base. Figure 4 shows a
modified form of cap in which the seat for the bulb is at d. a is the bulb which
may be made of flint or other glass, opaline, or other material used for lamp bulbs,
and may be of any suitable form.
The neck (Figure 1) instead of being a tube of some centimetres in length,
as usual, is cut off close up to the shoulder of the bulb at c so as to present a
cylindrical section. The neck of the bulb thus prepared is suitably metallized
for example by reducing platinum chloride upon the neck of the bulb and electro-
plating it with copper so as to render it capable of adhesion when metallic solder
is used. The neck of the bulb is such that it may fit easily in a seat
or cup of any suitable form of which the use is to contain a certain
quantity of solder. The cap may be fitted to the holder by means
of a bayonet joint, screw, or other means of fixing. The cap may be of moulded
glass, opaline, porcelain, earthenware, enamelled metal, etc. provided it be of
suitable form and give passage to the leading-in wires whilst remaining air-tight
and also furnish a metallized seat or cup for the neck of the bulb when metallic
solder is used.
In the example illustrated in Figures 2 and 3 the lamp is to be fixed by a
bayonet joint, the cap d being made of porcelain and the terminals, which also
serve as supports for the filament or filaments, being fixed at the moment of glaz-
ing the porcelain, and the metal holding seat or cup e.
cap
To produce a lamp on my system I proceed in the following manner:-I take
a bulb a provided with the usual exhausting tube and in the groove e of the
d or at the bottom of the cap d I place some metallic solder, preferably
ordinary plumber's solder, although any other kind of solder may be employed.
The filament is united by any suitable means to the terminals. The whole or
more exactly the cap d, is then brought to a temperature which will permit of the
fusion of the solder which after cooling will hold the whole in place and ensure
a perfectly air-tight joint.
When ceramic cement is used the method of procedure is much the same
except that the cap d is placed in a suitable oven and that instead of solder, a
few grains of enamel or highly fusible lead glaze would be placed around the
joint. It is necessary in this case to cool very slowly in order to avoid cracks
caused by too sudden cooling, and it is on account of this difficulty in the cooling
that metallic solder is preferred.
It now only remains to exhaust the air and seal the bulb at the blow-pipe, to
have a lamp ready for use.
I will now describe how, when the lamp becomes unserviceable by the wearing

page_text: out of the filament for example, I am enabled to obtain a new lamp at a minimum
expense. After first slightly grinding off the point of sealing so as to admit air
to the bulb, I heat the cap to a suitable temperature for the purpose of separating
it from the bulb. The bulb is then again provided with an exhausting tube and
if necessary all traces of carbon which may have become deposited within it are
removed. By then repeating the same operations as previously described, an
absolutely new lamp is obtained at the cost of a new filament, whereas a lamp
made in the ordinary way herein referred to would be entirely useless in the
event of the filament becoming unserviceable.
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. The combination, with an incandescent lamp bulb, of a cap adapted to fit
the mouth of the bulb and of a joint formed of fusible material capable of
becoming united by fusion both to the cap and to the bulb so as to form an air-
tight closure therefor as specified.
2. The combination, with an incandescent lamp bulb, of a cap fitted with ter-
minals and conductors for attachment of the filament and adapted to fit the mouth
of the bulb and of a joint formed of fusible material capable of becoming united
by fusion both to the cap and to the bulb so as to form an air tight closure therefor
as specified.
3. The method of making an incandescent lamp which consists in uniting the
cap d to the bulb a by the fusion of a fusible metallic or ceramic solder so as to
admit of the separation of the parts for use over again, by fusion of the joint as
specified.
Thadh: 10th
1000
A. M. & WM. CLARK,
Chartered Patent Agents, 53, Chancery Lane, London.