IMPROVE- MENTS IN INCANDESCENT ELECTRIC LAMPS
Year: 1882

page_text: LETTERS PATENT to John Jameson of Akenside Hill in the City and County
of Newcastle upon Tyne, Consulting Engineer for an Invention of IMPROVE-
MENTS IN INCANDESCENT ELECTRIC LAMPS.
PROVISIONAL SPECIFICATION left by the said John Jameson at the
Office of the Commissioners of Patents on the 9th November 1882.
JOHN JAMESON of Akenside Hill in the City and County of Newcastle upon
Tyne, Consulting Engineer.-IMPROVEMENTS IN INCANDESCENT ELECTRIC LAMPS
My Invention of Improvements in Incandescent Electric Lamps whereby the
efficiency and endurance of the same are increased,-consist in combination and
arrangement whereby the carbon filament of an Incandescent electric lamp under
ignition may be thickened or reduced in section at will or kept approximately
uniform by being supplied continuously with a restricted supply of more or less
attenuated hydro-carbon gas or vapour so as to compensate for the dissipation due
to the incandescence and whereby the deposit on the glass envelope occasioned by
the decomposition of the hydrocarbon gas or vapour within the samo during
incandescence may be cleaned off. And I prefer to use this combination, and
arrangement of lamp with such provision as that patented by me on 12th October
1881, Nº 4439, so as to provide relays of filaments in case of accidental
rupture or of undue thickening, and so as to provide a cleaning device which may
be operated without access to the interior of the lamp.-My Invention may be
conveniently carried out as follows:-
I provide in the bedplate of the lamp an attachment to a supply of ordinary
illuminating gas with a graduated valve arrangement for convenience of regulating
the quantity of the same supplied, and a further attachment to an air pump, and
also an attachment by which I am enabled to let a limited and regulated supply of
air into the lamp if necessary and I provide also as described in the specification
of my patent already referred to of 12th October 1881, N° 4439.-a means
whereby if a filament should fail a new one may be either automatically or other-
wise substituted for it without unsealing the lamp, or some other convenient
Din A71

page_text: means of renewal of filament, and I provide also a means as set forth in
the same specification whereby the interior of the glass envelope may be cleaned
without unsealing or some other convenient means of cleaning the inside of the
glass. I then exhaust the lamp by means of the air pump to a high degree of
vacuum so as to avoid loss of heat from convection without however any special
provision for or effort to carry the attenuation to a very extreme point.-I may
then apply an unusually large current of electricity such as in ordinary
circumstances would soon cause the rupture of the filament and to compensate for
this or counteract this effect I sapply to the filament a regulated quantity of gas
keeping the air pump in operation all the time so as that the decomposition of the 1
gas shall cause very hard deposit on the most highly heated parts of the filament
and make up any part which may be weakening by dissipation and when the
obscuration of the glass envelope becomes of importance I clean it off.-If by
inattention or by long use of a too full supply of gas, the carbon filament has
become unduly thickened I allow a small supply of air to pass through the lamp so 1
as to reduce it regulating the quantity so as to avoid actual rupture.
By these means I an enabled to realize the economy in the use of electricity
arising from-the use of a large current, I am enabled to diminish the necessity for
frequency in but yet to facilitate the renewal of filaments when required-and-I-at-
the same time can keep the glass envelope in a state of brightness and efficiency 2
altho' a hydrocarbon gas or vapour be admitted.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Jaineson in the Great Seal Patent Office on the 9th May
1883.
JOHN JAMESON of Akenside Hill, in the City and County of Newcastle upon
Tyne, Consulting Engineer IMPROVEMENTS IN INCANDESCENT ELECTRIC LAMPS,
WHEREBY THE EFFICIENCY AND ENDURANCE OF THE SAME ARE INCREASED. [sic.]
My Invention of Improvements in Incandescent Electric Lamps whereby the
efficiency and endurance of the same are increased consists in a combination, and
arrangement whereby the carbon filament of an Incandescent electric Lamp under
ignition may be thickened or reduced in section at will, or kept approximately
uniformn by being supplied continuously with a restricted supply of more or less
attenuated hydrocarbon gas or vapour so as to compensate for the dissipation due
to the incandescence and whereby the deposit on tlie glass envelope occasioned by
the decomposition of the hydrocarbon gas or vapour within the same during
incandescence, may be cleaned off; and I prefer to use this combination, and
arrangement of lamp with such provision as that patented by me on 12th October
1881. N° 4439 so as to provide relays of filaments in case of accidental rupture,
or of undue thickening, and so as to provide a cleaning device which may
be operated without access to the interior of the lamp-My Invention may be
conveniently carried out as follows:-I provide in the bedplate of the lamp which
may be made of brass or other convenient material an attachment to a supply of
ordinary illuminating gas or other hydrocarbon gas fluid or vapour with a graduated
valve arrangement for convenience of regulating the quantity of the same supplied,
and a further attachment to an air pump preferably a Tates air pump and also an
attachment by which I am enabled to let a limited and regulated supply of air into
the lamp if necessary and I provide also as described in the Specification of my
patent already referred to of 12th October 1881. N° 4439 a means whereby if a
filament should fail a new one may be either automatically or otherwise substituted
for it without unsealing the lamp, or some other convenient means of renewal of
filament, and I provide also a means as set forth in the same specification whereby
the interior of the glass envelope may be cleaned without unsealing or some other
convenient means of cleaning the inside of the glass.-I then exhaust the lamp by
means of the air pump to a high degree of vacuum so as to avoid loss of heat from
convection without however any special provision for or effort to carry the
attenuation to a very extreme point-I may then apply an unusually large current
of electricity such as in ordinary circumstances would soon cause the rupture of
the filament and to compensate for this, or counteract this effect I supply to the
filament a regulated quantity of hydrocarbon gas fluid or vapour keeping the air
pump in operation all the time or intermitting it if desired so as that the
decomposition of the gas shall cause very hard deposit of carbon on the most
highly heated parts of the filament, and make up any part which may be weakening
by dissipation, and when the obscuration of the glass envelope becomes of
importance I clean it off. If by inattention or by long use of a too full supply of
gas, the carbon filament has become unduly thickened I either replace it by another
ilament or I allow a small supply of air to pass through the lamp so as to reduce
it, regulating the quantity so as to avoid actual rupture or undue attenuation of the
ilament. By these means I am enabled to realize the economy in the use of
lectricity arising from the use of a large current I am enabled to diminish the
ecessity for frequency in, but yet to facilitate the renewal of filaments when required,
nd I at the same time can keep the glass envelope in a state of brightness and

page_text: efficiency, although a hydrocarbon gas or vapour be admitted. Amongst the means
employed for renewal of the carbon filament, and for the cleaning of the lamp although
I prefer to use the device mentioned in my before referred to Specification of patent
dated 12 October 1881. I may employ an arrangement operated after removal
of the glass envelope so constructing the envelope as that it shall bear upon for
instance an India Rubber washer or other equivalent device for securing an
approximately air tight joint, and I may use a single filament in the lamp, or a
series of filainents to be used in succession, And I may also clean the glass by any
of the means described in my before mentioned patent or if a joint such as that
last described be fitted to the lamp I may remove the glass and clean the inside by
hand when desired.-Having thus described the nature of my invention and tho
manner in which the same is to be performed I will define what I consider to be
novel and valuable in the same and therefore claim as follows:-
1 The arrangement for supply to an Incandescent lamp during the time of its
use of a hydrocarbon fluid gas, or vapour, so as to compensate for, or make up the loss
due to its incandescence.
2nd The before mentioned or any analagous arrangement in combination with a
method of cleaning the inside of the glass envelope substantially as described.:
In Witness whereof I the said John Jameson have hereunto set my hand and.
seal this fifth day of May in the year of our Lord, one thousand eight
hundred and eighty-three.