Improvements in the Manufacture of Hoods or Mantles for Burners Used in Incandescent Gas-lighting.
Year: 1889

page_text: Date of Application, 23rd Apr., 1689-Accepted, 27th July, 1889
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Hoods or Mantles for Burners
Used in Incandescent Gas-lighting.
We LEONARD PAGET, Electrician and Chemist of No. 145 West 41st Street, New
York and CHARLES I. KINTNER, Electrician of No. 68 West 39th Street, New York
both of United States of America 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 :—
This invention relates particularly to incandescent hoods or mantles of the kind or
class in which a non-friable base or support is coated with luminiferous material
and its object is to devise an incandescent hood or mantle which shall have great
durability.
To this end the invention consists in the novel incandescent hood or mantle and
process hereinafter described by which the same is made.
It is not new to cover with an earthy luminiferous substance, like magnesia, a
non-friable base or support, such as platinum wire, by causing the luminiferous
substance to adhere to the exterior surface of such base or support in several ways
which are well known, and therefore, need not be described here.
But in all of those processes by which the luminiferous material is coated upon a
base or support there is not an absolute integrality of connection between the two,
by which is meant that the luminiferous material does not penetrate, or is not
absorbed into the pores of the non-friable base or support
In the incandescent hood or mantle hereinafter described there is absolute integrality
of connection between the two. A metallic wire preferably of steel or platinum, or any
metal in which there is little or no carbon-although fair results may be obtained when
some grades of iron-wire are used. This wire is formed into an incandescent hood or
mantle of the desired configuration or shape either by weaving or in any preferred manner,
and then a solution is made preferably alcoholic, of some earthy material, as for instance,
an alcoholic solution of chloride of magnesium, it being preferably a saturated solution.
The ends of the incandescent hood or mantle are then connected to an electrical
generator by any preferred means the said generator having sufficient current capacity
to heat the entire incandescent hood or mantle to a dull red temperature in the
atmosphere when in operation.
To avoid danger of an explosion, however care should be taken to entirely immerse
the incandescent hood or inantle thus connected in the electrical circuit in the solution
of alcohol, before the current is closed and the generator is operatively connected.
Of course any generator of electricity giving the necessary current tension and supply
may be used.
When the metallic hood or mantle becomes thus heated to the desired temperature,
its surface pores expand or enlarge very materially. The heat generated by the
electrical current, besides expanding the pores of the support volatilizes the solution
and causes the magnesia-or oxide of magnesium held in solution to be absorded into
the said pores. This process is continued until a coating of the desired thickness of
the magnesia (or magnesium oxide) attaches itself to those particles which have been
already absorbed and to the surface of the wire itself.
use.
The incandescent hood or mantle is now removed from the bath, and is ready for
Excellent results have been obtained from an incandescent hood or mantle
prepared by this process upon a platinum wire, which after the process failed to dis-
close any coating of magnesia, or magnesium oxide thus showing that the luminiferous
material or magnesia was absorbed into the pores of the wire.
The incandescent hood or mantle may if desired be heated before immersion, and
by other means than electrical, and then dipped into the solution continuing the heat-
ing and dipping alternately until the desired coating is obtained.

page_text: "
It is preferred, however, to use the electrical process of heating and also to heat
during the immersion of the hood or mantle in the solution, for the reason that thi
process gives a more even coating and the oxide appears to penetrate further into the
support, and this latter is regarded a very important feature.
By: this process an incandescent hood or mantle is obtained in which the union
between the base or support and the luminiferous substance is so intimate that any
difference in the coefficients of expansion between the two prevents rupture of the
luminiferous material, thereby giving increased life to the incandescent hood or
mantle produced.
Chloride of magnesium is the preferred solution but other solutions may be used, as
nitrate of magnesium nitrate of aluminium and chloride of zirconium.
It is well known in the art of electrical illumination that carbon and analogous
conducting filaments which decrease in their electrical resistance on heating to
incandescence are used in preference to metal conductors which increase their
resistance under like conditions thereby wasting electrical energy;
This increase in the resistance of a metallic conductor is due to the increased
porosity of the metal under heat. In carbon and analogous incandescent electric
light conductors, there is increased porosity for increased temperature.
This feature of increased porosity in heated metal conductors is taken advantage of
to cause the incandescing material to penetrate the pores of a non-friable base or
support and in this feature lies the essence of the invention.
It is old to dissolve an oxide in an acid and then coat a wire with the solution,
and finally subject the wire thus coated to heat as described in British Letters Patent
to Edison No. 5306, 1878, but this process is the reverse of that herein described and
cannot act to cause the oxide to penetrate the pores.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is
First. The within described process of preparing an incandescent hood or mantle
for burners used for incandescent gas lighting which consists in causing a luminiferous
substance to penetrate the pores of a non-friable base or support substantially as
described.
Second. The within described process of preparing an incandescent hood or mantle
which consists in causing a luminiferous substance to penetrate the pores of a non-
friable base or support and continuing this process until a coating of the desired
thickness is obtained upon the exterior surface of the support substantially as
described.
Third. The herein described process of preparing an incandescent hood or mantle
which consists in heating a metallic base or support in a solution containing a
luminiferous substance to the required temperature and for the necessary time to
cause the expanded pores of the metal to absorb the desired quantity of the lumi-
niferous substance substantially as described.
Fourth. The herein described process of producing an incandescent hood or mantle
which consists in electrically heating a metallic base or support in an alcoholic solution
containing a luminiferous substance, substantially as described.
Fifth. The herein described process of producing an incandescent hood or mantle
consisting in electrically heating a metallic base or support while immersed in an
alcoholic solution containing a salt that will produce a highly refractory substance as
oxide of magnesium, substantially as described.
Sixth. The herein described process of producing an incandescent hood or mantle
consisting in electrically heating a metallic base or support therefor in a solution of
alcohol and a salt that will produce a refractory snbstance, and continuing this action
until the surface pores of the base or support are filled and a coating of the desired
thickness is formed about said base or support substantially as described.
Seventh. An incandescent hood or mantle consisting of a non-friable base or
support having a luminiferous substance embedded in its pores whereby integrality of

page_text: connection exists between the base or support and the luminiferous substance sub-
stantially as described.
Eighth. An incandescent hood or mantle consisting of a non-friable base or support
holding a luminiferous substance in its surface pores, and an exterior coating of said
luminiferous material attached to the embedded material and to the surface of the base
or support, substantially as described.
Ninth. An incandescent hood or mantle consisting of a metallic base or support
having a coating of a luminiferous material which penetrates the surface pores of the
base or support substantially as described.
Tenth. An incandescent hood or mantle consisting of a metallic base or support
having a coating of a luminiferous material of highly refractory nature which
penetrates the surface pores of the base or support and forms also a coating about the
exterior surface the two being thus integrally united, substantially as described.
Eleventh. An incandescent hood or mantle consisting of a metallic wire base or
support coated with a luminiferous material which penetrates the surface pores of the
wire and thus becomes integrally attached to said base or support substantially as
described.
Twelfth. An incandescent hood or mantle consisting of a non-friable base or
support having magnesium oxide embedded in its surface pores, substantially as
described.
Thirteenth. An incandescent hood or mantle consisting of a non-friable base or
support having magnesium oxide embedded in its surface pores, and also a coating of
said oxide on the surface of said base or support, substantially as described.
Fourteenth. An incandescent hood or mantle consisting of a metallic base or
support baving magnesium oxide embedded in its surface pores and covering also the
entire surface of the base or support, substantially as described.
D
09.1 JA 1000
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicants.