IMPROVEMENTS IN ELECTRIC LAMPS
Year: 1880

page_text: LETTERS PATENT to Herbert John Haddan, of the Firm of Herbert and
Company, Solicitors of Patents, of 67, Strand, in the City of Westininster,
Civil Engineer, for an Invention of "IMPROVEMENTS IN ELECTRIC LAMPS."
A communication from abroad by Antoine Bureau, of Gand, in the Kingdom
of Belgium.
PROVISIONAL SPECIFICATION left by the said Herbert John Haddan at the
Office of the Commissioners of Patents on the 26th April 1880.
HERBERT JOHN HADDAN, of the Firm of Herbert and Company, Solicitors of
Patents, of 67, Strand, in the City of Westminster, Civil Engineer. "LMPROVEMENTS
IN ELECTRIC LAMPS." A communication from abroad by Antoine Bureau, of
Gand, in the Kingdom of Belgium.
The Invention relates to a new type of electric lamps, and consists in guiding the
voltaic arc in a block of refractory material, and in the method of rendering the
light constant and of the desired tint. This may be effected in the following
manner:-The extremities of the carbons are embedded in the refractory material,
and the latter cut out so as to form a vault directed towards the side which is to
bo illuminated. At the top of this vault are two orificies which communicato with
the points of the carbons, thereby forcing the arc to take the prescribed way. This
principle reduces the consumption of the carbons by removing from them the action
of the air, thus avoiding their combustion; it secures also by the high temperature
of the refractory block a disaggregation of the carbons favorable to the formation of
the voltaic are and permits the application of currents of small quantity. The
carbons are made to advance in proportion to their consumption either by their
own weight or by means of counterweights and springs. The lifting of the lamp
is effected by means of rods of plumbago or other suitable material connecting the
carbons through the said orifices. For operating the lamps continuous or alternating
currents may be used as desired. The carbons may form any desired angle
against each other, and may even be placed in two different planes, and in view of
the small quantity of electricity necessary the shape and dimension of the carbon
may be greatly varied. One of the carbon electrodes may be replaced by a metallic
electrode. The refractory material employed may be formed of one or more pieces
joined together or simply placed near each other; it can be cut out so as to show
the carbon points in the direction desired, and the shape of the vault may vary
according to the nature of the spaco to be illuminated.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Herbert John Haddan in the Great Seal Patent Office on the 26th
October 1880.
HERBERT JOHN HADDAN, of the Firm of Herbert and Company, Solicitors of
Patents, of 67, Strand, in the City of Westminster, Civil Engineer. "IMPROVEMENTS
IN ELECTRIC LAMPS." A cominunication from abroad by Antoino Bureau, of
Gand, in the Kingdom of Belgium.
This system of lamps is based on a new principle which consists in surrounding
the electrodes of the voltaic are typo of electric lamps by a block of refractory
material, for instance marble, which protects the poles against the air, compels the
voltaic arc to take a prescribed line, and may be used to give a special tint to the
electric light. For this purpose the contiguous extremities of the carbons are
embedded in the refractory material and the latter cut out so as to form a vault
directed towards the side which is to be illuminated. At the top of this vault are
two orfices which communicate with the points of the carbons, thereby forcing the
are to take the prescribed way. This principle reduces the consumption of the
carbous by protecting them against the destructive action of the air, that is to say,
by avoiding more or less their combustion; it secures also by the high temperaturo
of the refractory block a disaggregation of the carbons favourable to the formation
of the voltaic arc, and permits the application of currents of small quantity. The
carbons are made to advance in proportion to their consumption either by their
own weight or by means of counter weights and springs. The lighting of the lamp
is effected by means of rods of plumbago or other suitable material connecting the
carbons through the said orfices. For operating the lamps continuous or alternating
currents may be used as desired. The carbons may form any desired angle against
each other, and may even be placed in two different planes. In view of the small
quantity of electricity necessary, the shape and dimensions of the carbons may be
greatly varied.
One of the carbon electrodes may be replaced by a metallic
electrode. The refractory material employed may be forined of one or more pieces
joined together, or simply placed near each other; it can be cut out like a vault so
as to distribute the light in the direction desired, and the shape of the vault may
vary according to the nature of the space to be illuminated. This lamp makes any
mechanism or superintendence unnecessary, and perinits a prolonged use with
carbons of small length. I am aware that blocks of refractory material have been
used for guiding the electrodes and for limiting their motion. I do not, therefore,
claim the application of refractory material generally, but the special manner of
applying the same, whereby its function becomes essentially different from that
hitherto assigned to it. In the lamp herein described the refractory material serves
to force the arc, that is to say, to compel it to take a way from which it cannot
deviate. Experience has shown that this is the only means of obtaining by an
arcan absolutely fixed light. In the lamps hitherto used the carbon points are
visible, exposed to the air, and therefore subject to rapid combustion. In this lamps,
however, the carbon points are not seen, the light being produced by the heating
effect of the carbon vapors of the voltaic are on the incandescent material, and the
color of the light is that of the heated refractory material, generally a peculiar
gold colour. The voltaic are touches the refractory material on its entire length
without effecting any appreciable destruction. The present arrangement has also
the advantage of protecting tho are against cooling, and thus increasing the useful
effect, the length of are obtainable being greater than in other lamps. As the
carbon only serve to produce carbon vapors, their shape and dimensions as well
as their quality have no great influence on the light.
The refractory material preferably used for this lamp is marble, which has not
been applied in other systems of electric lamps.

page_text: The annexed Drawing shows a suspension lamp embodying this Invention, and
constituting one of a great many applications of the new principle. Fig. 1 is a
side elevation; Fig. 2, a cross section; and Fig. 3, a section through the carbon
guides.
constituting one of a great many applications of the new principle. Fig. 1 is a
side elevation; Fig. 2, a cross section; and Fig. 3, a section through the carbon
guides.
S designates the frame.
D, a case containing the refractory material.
M, the block of refractory material.
A, the way of the voltaic arc (crown of the vault).
B, B, binding posts or joints for the current conductors.
T, T, bars turning on centres and conducting the currents to the carbons.
C, C, carbons.
I do not limit myself to the special form of lamp shown and described, because it
may be varied in many ways without departing from the principle of my Invention,
but what I claim is,-
1. An electric lamp provided with a guide of refractory material which forces the
are to take a prescribed and fixed way.
2. In electric lamps a block of refractory material which so surrounds the poles
of the electrodes as to hide them from view and prevent the free access of air, and
which is provided with orifices serving as a guide for the voltaic arc.
3. In electric lamps a block of refractory material which so surrounds the poles
of the electrodes as to hide them from view, and which is cut out like a vault for
distributing the light in the desired direction, substantially as described.
4. The combination of carbons C with guide block M, conducting rods T turning
on centre, substantially as and for the purpose described.
5. The combination of carbons C with guide block M enclosed in casing D,
conducting rods T turning on centres, and suspension frame S, substantially as and
for the purpose described.
In witness whereof, I, the said Herbert John Haddan, have hereunto set
my hand and seal, this Twenty sixth day of October, 1880.
H. J. HADDAN.
(L.S.)