Popa or Incandescence Lamps.
Year: 1886

page_text: Date of Application, 4th Dec., 1886
Complete Left, 13th Apr., 1887.
Complete Accepted, 13th May, 1887
Popa
or Incandescence Lamps.
I, ALEXANDER MELVILLE CLARK, of the firm of A. M. and Wm. Clark, of
53, Chancery Lane, in the County of Middlesex, Fellow of the Institute of Patent
Agents, do hereby declare the nature of the said Invention to be as follows:-
This Invention consists in a process of repairing broken carbon filaments of glow or
incandescence electric lamps. It is well known that after a certain period of service
such filaments are liable to break and no means of repairing them has heretofore been
devised. To reunite the broken carbon in such a way as to permit of the current
passing and render the lamp again as serviceable as before is the object of the process
of this Invention.
Reference is to be had to the accompanying drawing wherein figure 1 shows a glow
lamp in working order, figure 2 shews the same lamp with the filament broken while
figure 3 shews the same lamp after it has been repaired but before the bulb has been
again exhausted of air and resealed.
According to this process a hole is cut in the end of the glass bulb & containing the
broken filament e as at a (figure 3) to allow of introducing into said bulb a hydro-
carbon such as retinaphtha (CHS) retinyl (CH2) retinol (32 H10) etc. etc., all the
hydrocarbons whether liquid or gaseous, being capable of conducing to the desired
result. The selection would depend upon the perfection of the tools employed, but
liquid hydro carbons are preferred. After the bulb is filled with a product rich in
carbon, the sundered ends of the filament are brought together by means of nippers
and the current is then passed through the filament which immediately becomes
welded or united together by a deposit of carbon which makes a good and permanent
joint. The filament having been thus repaired it is only necessary to reestablish the
vacuum in the bulb, for which purpose a glass tube is joined to the bulb of the

page_text: orifice a and connected with a Sprengel pump by which the bulb is exhausted and is
afterwards rescaled in the ordinary way which needs no description. The lamp thus
repaired is again ready for service which may exceed in duration its original period of
service, and it will give a whiter light, the carbon deposited being purer than that
composing the filament.
The liquid hydro-carbon also serves to clean the bulbs of the carbonaceous deposit,
with which they become coated in consequence of the impurity of the carbon filament,
and as during the welding operation the entire filament becomes covered with a light
coating of carbon of greater purity, the bulb is no longer liable to become blackened
in use.
Moreover, the resistance of such lamps increases after prolonged use, a current of
greater tension is required in order that they may produce a light of the same intensity
as at first.
This has a very objectional effect where a large number of these lamps are used
together, the older ones being of a reddish hue, while others which are new and have
the same electro-motive force, give a white light. In other words, new lamps of
100 volts require after being a certain time in use, a current of 105 volts and even
more. Lamps which have been repaired by this improved process are free from
this objection, as the deposit of carbon produced as above mentioned, decreases
their resistance and the carbon being pure, the lamp will last for a very considerable
time.
The invention is applicable to filaments of vegetable origin, such as those of bamboo
(Edison lamp) parchment paper (Swan) bristol board (Maxim) couch-grass (Lane-
Fox) or of animal fibre, such as hair (Woodhouse) or to carbon obtained by the
draw-plate as in the Gérard lamp.
Dated this 4th day of December 1986
A. MELVILLE CLARK.
By A. M. & Wm. Clark,
53, Chancery Lane, London,
Patent Agents.

page_text: COMPLETE SPECIFICATION.
An Improved Process of Repairing the Filaments of Electric Glow
or Incandescence Lamps.
I, ALEXANDER MELVILLE CLARK, of the firm of A. M. & Wm. Clark, of
53, Chancery Lane, in the County of Middlesex, Fellow of the Institute of Patent
Agents, do hereby declare the nature of this Invention (a communication to me
from abroad by Casimir Pauthonier of 17 Rue Danton, Levallois-Perret (Seine)
France, Electrician, and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement :-
This invention consists in a process of repairing broken carbon filaments of glow or
incandescence electric lamps. It is well known that after a certain period of service
such filaments are liable to break and no means of repairing them has heretofore been
devised. To reunite the broken carbon in such a way as to permit of the current
passing and render the lamp again as serviceable as before is the object of the process
of this invention.
Reference is to be had to the drawings which accompany my provisional
specification, wherein figure 1 shows a glow lamp in working order, figure 2
shews the same lamp with the filament broken while figure 3 shews the same lamp
after it has been repaired but before the bulb has been again exhausted of air and
resealed.
According to this process a hole is cut in the end of the glass bulb b containing the
broken filament c as at a (figure 3) to allow of introducing into said bulb a hydro-
carbon such as retinaphtha (CH) retinyl (C18 H12) retinol (C32 H¹) etc. etc., all the
hydro carbons whether liquid or gaseous, being capable of conducing to the desired
result. The selection would depend upon the perfection of the tools employed, but
liquid hydro carbons are preferred. After the bulb is filled with a product rich in
carbon, the sundered ends of the filament are brought together by means of nippers
and the current is then passed through the filament which immediately becomes welded
or united together by a deposit of carbon which makes a good and permanent joint.
The filament having been thus repaired it is only necessary to reestablish the vacuum
in the bulb, for which purpose a glass tube is joined to the bulb of the orifice a and
connected with a Sprengel pump by which the bulb is exhausted and is afterwards
rescaled in the ordinary way which needs no description. The lamp thus repaired is
again ready for service which may exceed in duration its original period of service,
and it will give a whiter light, the carbon deposited being purer than that composing
the filament.
The liquid hydro-carbon also serves to clean the bulbs of the carbonaceous deposit,
with which they become coated in consequence of the impurity of the carbon filament,
and as during the welding operation the entire filament becomes covered with a light
coating of carbon of greater purity, the bulb is no longer liable to become blackened
in use. Moreover, the resistance of such lamps increases after prolonged use and a

page_text: current of greater tension is required in order that they may produce a light of the
same intensity as at first. This has a very objectionable effect where a large number
of these lamps are used together, the older ones being of a reddish hue while others,
which are new and have the same electro-motive force, give a white light. In other
words, new lamps of 100 volts require, after being a certain time in use, a current of
105 volts and even more. Lamps which have been repaired by this improved process
are free from this objection, as the deposit of carbon produced as above mentioned
decreases their resistance, and the carbon being pure, the lamp will last for a very
considerable time.
The Invention is applicable'to filaments of vegetable origin such as those of bamboo
(Edison lamp) parchment paper (Swan) bristol board (Maxim) couch grass (Lane-Fox)
or of animal fibre such as hair (Woodhouse) or to carbon obtained by the draw-plate,
as in the Gérard lamp.
Having now particularly described and ascertained the nature of the said Invention
and in what manner the same is to be performed, I declare that what I claim is :-
The herein described process of repairing the filaments of incandescent lamps,
which consists in the introduction into the lamp containing the broken filament, of a
liquid or gaseous hydro-carbon, bringing together the ends of the sundered parts of the
filament, and then passing the current through the whole length of the filament, for
the purpose of making a welded joint by the deposit of carbon, all substantially as
hereinbefore specified.
n
111
11
A. MELVILLE CLARK.
By A. M. &. Wm. Clark,
53, Chancery Lane, London,
Patent Agents.