Improvements in the Manufacture of Radiant Tissue for Lamps.
Year: 1894

page_text: COMPLETE SPECIFICATION.
Improvements in the Manufacture of Radiant Tissue for Lamps.
I FREDERIC DE MARE, Engineer, of 50 Rue des Moines, Paris, in the Republic
of France, 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 :-
My process of manufacturing a radiant tissue has for its object to produce in
different shapes, (sleeves, cones, sheets, yew leaf &c.) surfaces of refractory material
in the greatest degree of tenuity and solidity compatible with their employment.
In principle it consists in holding in suspension or in dissolution in a collodoide the
oxides which are difficult to reduce or volatilise, such as those of zirconium erbium,
yttrium, silicon &c. &c.
In practice utilize the property which certain of these metals possess of forming
an ethyl compound (that is to say of compounds of ether) which ethers being mixed
with alcohols are able to form a collodion by the dissolving of a certain quantity of
azotic cellulose.
This collodion (the solvent of which is a mixture of one or more of these ether
compounds and of alcohol which may or may not hold in suspension or solution
oxides or salts of these oxides) is drawn into a thread more, or less fine, by its
passage through a draw plate, either in free air or in a liquid suitable for hastening
its solidification.
It is with the thread thus obtained that I weave by the ordinary methods my
sleeves, cones, sheets &c. which subsequent heating deprives of organic matter
leaving the oxides in a state of molecular subdivision which facilitates their
irradiation, whilst at the same time the continuity of the texture insures great
solidity and durability.
Instead of obtaining my threads by passing collodion under pressure through a
draw plate I can take advantage of the high temperature produced by the electric
are to raise to fusing point the refractory substances such as zirconium, magnesium,
yttrium or others and as these bodies pass through a soft state I utilise this
property to draw them into threads as is done with glass. It is necessary that
these threads be pure, and care must therefore be taken to construct the furnace in
which the fusing is effected of the same material as that which is to be melted in
order to avoid forming alloys which are more, and always too, fusible and non-
irradiative. By proceeding in this manner I have been able to obtain also cylinders
of quartz or pure silica which whilst being too large to make radiant with a burner
of simply mixed air are excellent for oxyhydrogen burners, that is to say, for large
burners, offering as compared to the lime hitherto used, the double advantage of
not cracking and of being uninfluenced by the hygrometric condition of the
atmosphere, which permits of the same piece being used a great number of times.
the wear being very small.
Irradiation from a solid body made incandescent in any given flame being
directly proportional to the extent of surface, it is necessary in the case now under
consideration to produce a tissue with exceedingly fine threads whilst keeping in
mind solidity which is necessary in order to insure their practical employment.
I have been able to realise this desideratum in the following manner.
With very fine metallic wire, of platinum for example, which constitutes the
warp of the work, and threads of my radiant tissue, I manufacture what is called in
embroidery a chenille, that is to say a collection of threads more or less fine
radiating from the warp. This chenille which is made in long lengths is trimmed
into the shape of lengthened spindles, and the warp may be even bared between
each spindle.

page_text: The length of the spindle is equal to the length of the radiant surfaces. The
slope of the spindle is calculated so that according to the dimensions of the surfaces
required (cones or discs) the radiating threads of two neighbouring spindles may
touch. For example, to form a cone, I proceed as follows:-
On a light ring of thin metal, and having a diameter slightly larger than the
burner on which it is to be made radiant, I fix a series of spindles, using the bare
part of the warp, that at the lower part for fixing it to the ring, that at the top.of
the spindle to form at the top of the cone the supporting ring.
This arrangement insures great solidity on account of the presence of the metallic
warp whilst at the same time it permits the use of very fine threads for increasing
the surface of the radiant material. Expansions are free and the surfaces can be
either suspended or rest on their base without fear of collapsing.
In order to economise the platinum, and also to increase the closeness of the
wisps of radiant threads, I make my chenille with a single warp thread a (Fig. 6)
and I tie side by side by a simple knot, a series of wisps 6 of my thread which I
then turn to give them the necessary shape. Instead of having the ends of the
wisps of thread free as shown (Fig. 6) I can obtain them in loops by winding the
thread on a round, flat or otherwise shaped mandril and of suitable size on which
I tie it by a double knot before tieing it by a similar knot on the warp thread a
(see Fig. 7).
In a general manner I reserve the right of making my tissue of such kind as I
wish, (tulle, muslin, Jersey, point &c. &c.) but on the grounds above mentioned I prefer
to adopt chenille, the warp of which is of fine platinum thread or of thread of the
same nature as the chenille; as regards the shape to be then given to the radiant
surface it must be the same as the flame and of slightly larger dimensions; flat for
the wing burner, cylindrical or conical for burners of the Bengel or Argand type,
semicircular for recuperative burners. I have further found that the conical yew
leaf form is equally suitable for lighting, provided that the burner is suitable.
I could therefore adopt this shape on my ejector burner patented separately and
which I preferably use for the application of my tissue whilst still pointing out
what is of the greatest importance, that my tissue is applicable to all kinds of
hydrocarbon gas or petroleum burners burning with a white flame, such as the wing
burner with slit, the Manchester burner, the Bengel or Argand type of burner or
the recuperative burners.
In the accompanying sheet of drawings several forms of my radiant tissue are
shown.
Fig. 1 is a cylindro-conical sleeve applied to my own system of burner.
Fig. 2 shows my tissue in leaf shape set in the centre of my own system of
burner.
Fig. 3 slightly conical sleeve applied to a Bengel or Argand burner.
Fig. 4. Front and side view of two parallel frames applied to a wing burner.
Fig. 5. Plan and section of a frame intended for a recuperative burner.
Fig. 6 shows in three successive stages the production of the chenille in radiant
thread.
Fig. 7 shows a circle of radiant thread tied round a platinum wire.
Figs. 8 and 9 show a single warp thread in inverted U shape and in looped
thread.
Fig. 10 shows a series of burners combined to give flat flames.
Fig. 11 shows a burner provided with a gauze of radiant thread arranged in the
flame, shown in elevation.
The frames are of larger dimensions than the radiating surfaces in order to avoid
loss of heat and the rapid wear of the supports.
In pursuing my tests on the manufacture, and on the most suitable shape for my
radiant tissue, I have been led to study that of the flame and to conduct the
gaseous jet through orifices suitably combined.
Figs. 10 and 11 represent a series of these jets or burners; they are combined to

page_text: give flat flames. Flat flames are in fact the hottest by reason of a very active
combustion due to the large surface in contact with the oxygen of the air.
I have especially endeavoured in combining these burners to approach the form
of the filament in incandescent electric lamps, that is to say, to obtain flat flames
whose lengths are greater than their widths, in which I insert a filament of my
tissue either in chenille with platinum core or a series of wisps tied on this core by
a simple knot, or finally, by lace chain also on a platinum core. It is needless to
say that a filament of radiant thread is the only one to make this arrangement of
utility.
The platinum core and consequently the wisps of radiant material are curved,.
either in the shape of an inverted U, or as an inverted U with loop (Figs. 8 and 9).
The ends of the platinum core are fixed and sealed in the two small lateral conduits
of a ring of insulating material (steatite or otherwise). This ring which fits on the.
burner allows the filament to be rapidly placed in position or changed (see Fig. 11).
As regards the baking of this filament I take advantage of the conductability of
the core to pass a current through it which raises it to a white heat, carbonises and
bakes the radiant material without altering the shape and in a regular manner.
The flame of such a burner is protected by an oval glass c supported on a
similarly shaped gallery d (Fig. 11).
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1st. The special collodion formed by dissolving azotic cellulose in an ether or
mixture of ether compounds (silicate or zirconate of ethyl &c.) and of alcohol.
2nd. The increase of the metallic oxides contained in the collodion by the
previous solution of soluble salts with these oxides, or simply by the admixture of
these finely divided oxides with the above mentioned collodion.
3rd. The production of threads, and consequently of tissues, by drawing out the
collodion either in the air or under a suitable liquid (acidulated water or
otherwise).
4th. The production of the threads for radiant tissues by the fusion in an
electrical furnace of masses of the material constituting the tissue (zirconium.
magnesium or other oxides or earthy bases).
5th. The application of the radiant tissues as described, in any suitable shape, to
gas burners or other hydrocarbon burners to transform their calorific power into
emitted light.
6th. The method of manufacture and the employment of radiant surfaces by the
collection of wisps of the tissue in the style known industrially as chenille, this
chenille being formed by a warp of threads drawn from one of the above described
compositions.
7th. The arrangement of frames of suitable shape for stretching and fixing the
radiant tissue substantially as described.
8th. The employment of cast silica blocks for radiators of large power, called
oxyhydrogen burners.
9th. The shape of the burners and flames resulting therefrom (Figs. 10 and 11)
having for their object to make my radiant tissue incandescent.
10th. The shape of the filaments of radiant material formed on a core or warp of
platinum substantially as described.
11th. The method of carbonization and baking by the employment of an electric.
current circulating in the core or warp of platinum.
12th. The method of fixing the filaments on a collar of insulating material.
Dated this 21st dov of Now 1001
WHEATLEY & MACKENZIE,
40, Chancery Lane, London, W.C., Agents.