IMPROVEMENTS IN INCANDESCENT LAMPS
Year: 1882

page_text: LETTERS PATENT to John Rapieff, of No. 35 Queen Victoria Street, in the
City of London, Electrician, for an invention of "IMPROVEMENTS IN
INCANDESCENT LAMPS "
PROVISIONAL SPECIFICATION left by the said John Rapieff at the Office
of the Commissioners of Patents on the 6th May 1882.
JOHN RAPIEFF, of No. 35 Queen Victoria Street, in the City of London,
Electrician, "IMPROVEMENTS IN INCANDESCENT LAMPS "
This invention consists of improvements in the construction of Electric Lamps
made with carbon filaments or strips, by the carbonization of suitable organic
substances, cut before or afterwards in proper shape or form, and the deposition
upon them of pure carbon from carboniferous liquids, gases or vapours, by electricity
or heat, or both.
Besides the ordinary means, the carbon filament may be made by the carboni-
zation of organic substances such as collodion prepared from gun cotton flux etc.
and deposited from the solution by suitable means in the shape of sheets, plates or
ribands or threads, after which upon this may be deposited carbon in a pure state
from liquid gases or vapors.
Under the names of carboniferous gases or vapors I use Gazoline, Benzine,
Chloroform etc., but of more importance, gases or vapors obtained from liquids
not containing hydrogen, such as chemical compounds of carbon with Chlorine and
Bromine, Sulphur and Iodine, separate or together, or a mixture of these or any
other substances similar in natures.
To obtain the carbon filament by this deposition of the pure carbon thereon
from the above named gases or vapours, not only of equal resistance but also of
the same fineness of the grains of deposited carbon, I use an improved automatic
arrangement.
The volume or fineness of the grains of the deposited carbon on the said filament
depends upon the temperature to which it is heated (by the passing of the current
through it) providing this temperature is high enough to decompose the sur-
rounding carboniferous medium. (This process may be called the treatment of
the filament).

page_text: It is obvious therefore that if the temperature of the filament remains the same
or changes regularly the same fineness of the carbon deposit will result.
To obtain this necessary result I divide the electrical current into as many
branches as possible according to its strength and the requirements, and insert in
each of these branches the filament to be treated and an automatic electrical or
magneto-electrical arrangement which will come into play when the filament has
acquired the proper resistance, will cut off the heating current from it and at the
same time substitute in the circuit a resistance equal to that of the completed
filament; it is evident that the current in the other branches where the other
filaments are in the course of treatment will not be affected.
The carbon filaments may be round or flat in section and bent or cut into
different shapes such as the figure eight or thus & or any other curve, or to produce
more diffusion of light the flat filaments may be held in clamps which are placed
at an angle to each other
The clamps for the filaments (parts of which may be increased in section or
surface for this purpose) such as platinum, palladium, nickel, steel or other
suitable metal or carbon rivetted together by pressure or other suitable means
after which may be deposited on the points of junctions metal or carbon by
suitable means.
The clamps are connected to metallic conductors flat or round in section, straight,
curved, zigzag, or spiral, which may be wholly or partially sealed in the glass and
brought out at the side, bottom or inside of the lower part of the tubular end of
the glass ball or case, and I fix on the ends small buttons or projections or hooks
so as to make outside contact points.
For the more effectual sealing of the conductors I form the lower part of the
bulb or case into a tube cylindrical and slightly conical.
After the introduction of the carbon filament clamps and conductors into the
bulb, I take a glass thimble or cup of such a size as may be conveniently
introduced into this tube, leaving the annular space for the conductors as small
as possible.
To complete the sealing and to produce uniformity in the size of the finished
Lamps, I heat to the necessary degree the said tubular part of the lamps and
thimble, and after introducing into the latter a suitable core or tool, I squeeze the
whole together to form the desired shape. Any necessary part of this free annular
'space or thimble may be fitted with suitable cement or amalgam.
The glass forming the thimble or inner part may be continued between the
clamps so as to make a glass bridge between them. Sometimes I make this glass
or bulb of the lamps or part of it from fluorescent or opalescent glass.
The lamps may contain inert gases or vapors of simple bodies, such as Chlorine
Iodine, Bromine, Sulphur etc., or gases or vapors of any combination of carbon
with these at ordinary or any suitable pressure, or, as still better, a vacuum, before
the production of which the globe may be filled and washed with any of them so as
the said gases or vapors will form the residual medium.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said John Rapieff in the Great Seal Patent Office on the 4th November
1882.
JOHN RAPIEFF of 35 Queen Victoria Street in the City of London, Electrician.
"IMPROVEMENTS IN INCANDESCENT LAMPS."
This invention consists of improvements in the construction of Electric Lamps
made with carbon or other filaments or strips obtained either through the carboui-
zation by heat electricity or chemical means of suitable organic substances, cut or
bent before or afterwards in proper shape or form or made from suitable paste by
pressing through a die or otherwise and the deposition upon them of pure metallic
or crystalline carbon from carboniferous liquids, gases, or vapors, by electricity or
heat or both.
Besides the usual means, the carbon filament may be made by the carbonization
of organic substances, such as collodion prepared from gun cotton, flax and etcetera,
and deposited from the solution by suitable means in the shape of sheets, plates, or
ribands, or threads, after which upon this may be deposited carbon in a pure state
from liquid gases or vapors.
Under the names of carboniferous gases or vapors I use Gazoline, Napthaline,
Benzine, Chloroform, spirits or oils, in fact all hydro carbons etc. but, of more
importance, gases or vapours obtained from liquids not containing hydrogen, such
as chemical compounds of carbon with chlorine Bromine Iodine Sulphur or Selenium
and other substances similar in nature separate or together.
To obtain the carbon filament by this deposition of the pure crystalline or
metallic carbon thereon from the above named gases or vapors, not only of equal
resistance, but also of the same fineness of the grains of deposited carbon I use an
improved automatic arrangement.
The volume and fineness of the grains of the deposited carbon on the said filament
depends upon (1°) the temperature to which it is heated by the passage of the
current through it, providing this temperature is high enough to decompose the
surrounding carboniferous medium (2°) its richness and pressure of the gas or
vapours of the liquid taken for the purpose. (This process may be called the
treatment of the filament).
It is obvious therefore that if the temperature of the filament and other
conditions remains the same, or changes regularly according to requirement the
necessary regularity in size of the deposited carbon particles will be obtained.
To accomplish this necessary result I divide the electrical current into as many
branches as possible, according to its strength and the requirements, and insert in
each of these branches the filament to be treated and an automatic electrical or
magneto-electrical arrangement, which will come into play when the filament has
acquired the proper resistance, will cut off the heating current from it and at the
same time substitute in the circuit a resistance equal to that of the completed
filament; or automatically will change accordingly the strength of the current.
is evident that the current in the other branches where the other filaments are in
the course of treatment will not be affected.
It
To shorten the above described process of treatment I may deposit pure carbon
on the filament, or substances from which it is to be made, from the carboniferous
gases or vapours during the process of the carbonization of the said filament or
substances by surrounding them with an atmosphere or current of the said gases
or vapours at suitable pressure volume and temperature.
The carbon filaments may be round elliptical, square, prismatic in section or flat
and bent or cut into different shapes, such as the figure eight or thus & or any

page_text: other curve, or, to produce more diffusion of light, the flat filaments may be held
in clamps which are placed at an angle to each other.
But of all forms for the filament I prefer the form of a spiral or spirals, flat,
cylindrical, conical, single, or multiple; or the filament may be bent, or cut in
shape of zigzag which may be arranged flat or bent into cylinder, cone or any
other required form. I sometimes and preferably make the filament by carboni-
zation by heat electricity or chemical process purification and treatment of a
single thread or bundle of them of cotton wool, flax, hemp, or other fibrous
substances or strips or ribands made or cut of any textile material such as tulle,
tarlatan, muslin, etc.
The clamps for the filaments (parts of which may be increased in section or
surface for this purpose) such as platinum, palladium, irridium, nickel, steel,
or other suitable metal, or carbon, rivetted together by pressure or other suitable
means, after which may be deposited on the points of junctions metal or carbon by
any suitable means.
The clamps are connected to metallic conductors, flat or round, in section,
straight, curved, zigzag or spiral which may be wholly or partially sealed by
means of a holding piece of suitable shape made of glass, enamel, or amalgam and
introduced into the bulb or tubular part of the lamp.
.
The ends of the said conducting wires may be brought out at the side bottom
or inside of the lower part of the tubular end of the glass ball or case and I fix
on these ends small buttons or projections or hooks or rings so as to make outside
contact points.
.
For the more effectual sealing of the conductors I form the lower part of the
bulb or case into a tube, cylindrical or slightly conical:
After the fixing of a carbon filament, clamps, and conductors to the holding piece
I take a glass thimble or cup of such a size as may be conveniently introduced
into this tube, leaving the annular space for the conductors as small as possible, or
better still, I make in said thimble suitable recesses for them, or I fix or seal the
before mentioned conducting wires immediately to the said thimble or tubular part
of Lamp by means of suitable cement, amalgam, enamel, glass, pitch etc. and in this
case I may dispense with a separate holding piece.
After the introduction of the said thimble into the tubular part of the lamp to
complete the sealing and to produce uniformity in the size of the finished lamps I
heat to the necessary degree the said tubular part of the lamp and thimble and
after introducing into the latter a suitable core or tool I squeeze the whole together
by suitably shaped plyers or pincers to form the desired shape.
If I leave the aforesaid annular space I may fill any necessary part of it or of
the thimble with suitable cement, ainalgam, enamel etc.
The glass forming the thimble or holding piece or inner part may be continued
between the clamps or between the branches of the filament so as to make one or
more glass bridges screens or partitions between them for the purpose of obtaining
more complete insulation or separation between the said clamps and branches of
the filament of the lamp. The said bridges or partitions may be made separately
from any suitable insulating material and then fixed in the lamp.
I may make these glass bridges, screens, partitions or bulb of the lamps or part
of them or of the thimble from fluorescent phosphorescent or opalescent glass so as
to increase reflect and diffuse, the light.
The Lamps may contain inert and insulating gases or vapors of simple bodies
such as Chlorine, Iodine, Bromine, Sulphur, Silenium or gases or vapors of any
combination of the same and with or without carbon at ordinary or any suitable
pressure; or a partial vacuum may be formed in the lamps, before the production
of which the globe may be filled and washed once or several times with any of
the above mentioned substances so that the said gases or vapors will form the
residual medium
Having now described and ascertained the nature of my said invention and in
what the manner same is or may be performed.

page_text: I Claim as secured to me by the hereinbefore in part recited Letters Patent :-
Firstly In an incandescent Lamp, the use of a filament upon which is deposited
pure metallic or crystalline carbon, by heat, or by electricity, or both, from non-
hydrogenic compounds of carbon with Iodine, Chlorine, Bromine, Sulphur, Selenium
and substances similar in nature, substantially as hereinbefore described.
Secondly-The means and arrangements whereby I obtain carbon or other
filaments for Incandescent Lamps, not only of the same resistance but also of
the same regularity in grain of deposited pure crystalline or metallic carbon,
substantially as herein before described.
Thirdly-In an incandescent Lamp, the use of single or multiple carbon
filaments in a spiral or a zigzag form prepared from suitable paste, or of filaments
of any suitable shape made from cotton wool, flax, hemp, and other fibrous
substances, or made of strips or ribands of any suitable textile fabric such as tulle,
tarlalan, or muslin, by carbonization by heat, electricity, or chemical means,
separately or combined and subsequently treated substantially as herein before
described.
Fourthly: The construction and arrangement of an incandescent lamp and the
mode of sealing the conductors from the filament in to the glass case, and
producing uniformity in the size of the tubular part of the said case, substantially
as hereinbefore described.
:
Fifthly In an incandescent Lamp, the formation in the space between the
clamps, or between the clamps and the branches of the filament, of insulating
partitions or bridges, whereby I obtain more complete insulation of the clamps and
branches each from the other substantially as hereinbefore described.
Lastly-In an incandescent Lamp, the use of an inert and insulating medium
at any suitable pressure, formed of inert and insulating gases or vapours of simple
bodies, such as chlorine, Iodine, or Bromine or any combination of these between
themselves or with carbon, substantially as herein before described.
In witness whereof I the said John Rapieff have hereunto set my hand and
seal this first day of November in the year of our Lord One thousand
eight hundred and eighty two:
JOHN RAPIEFF. (L.S.)