Improvements in Electrical Incandescence Lamps.
Year: 1899

page_text: Date of Application, 22nd Mar., 1899
PROVISIONAL SPECIFICATION.
Improvements in Electrical Incandescence Lamps.
We, SIEMENS BROTHERS & CO. LIMITED, of 12, Queen Anne's Gate, West-
minster, in the County of London, Electrical Engineers, do hereby declare the
nature of this invention (as communicated to us from abroad by Siemens &
Halske Aktien Gesellschaft, of Markgrafen Strasse 94, Berlin, in the Empire
of Germany) to be as follows:-.
This invention relates to that kind of incandescence lamps in which a body
formed of a refractory material that is a dielectric in the cold condition (such
as oxides, mixtures of oxides, or the like) and which hereinafter we will call
the incandescence body" is in the first instance heated up to the necessary
temperature for rendering it a conductor, after which it is raised to and main-
tained in the state of incandescence by the current passed through the circuit.
In such lamps as heretofore proposed, it has been necessary to heat up the
whole of the incandescence body in the first instance for bringing the lamp into
action this being generally done by passing a sparking current directly from the
conducting socket or electrode at one end of the incandescence body to the
electrode at the other end.
According to the present invention the necessity for simultaneously heating
up the whole of the incandescence body in the first instance is obviated, by caus-
ing a sparking current or electric arc to operate in such manner as in the first
instance to heat to incandescence only a comparatively small portion of the incan-
descence body and then to successively heat up the other portions thereof until
the entire body has been raised to incandescence.
By this means the putting in action of the lamp can be effected by a current
of comparatively low pressure.
The invention can be carried out in a variety of ways, both as to the mode
of producing the sparking or electric arc in connection with the incandescence
body as also as to the mode of causing the arc to travel gradually along the latter;
and the devices employed for these purposes may either be automatic or non-
automatic. Thus according to one arrangement which we employ, the two elec-
trodes, between which the incandescence body in the form of a rod is held, are
put in temporary conducting connection by a contact arm pivotted to the one
electrode and temporarily held in contact with the other one. An extension of
this arm constitutes the armature of an electro-magnet the coil of which is
included in the lamp circuit, the current of which passes from such coil through
077

page_text: the upper electrode of the incandescence body, and through the pivotted contact
arm to the lower electrode. On the passage of such current the electromagnet in
attracting the armature causes the contact arm to be moved a short distance away
from the lower lamp electrode, and by this means an arc is formed between the
two, whereby the lower end of the incandescence body is heated to incandescence.
Owing to the known properties of the electric are this will gradually travel
upward between the contact arm and the incandescence body in proportion as
successive portions of this are rendered conducting by being successively heated,
and when by this means the entire body has become heated, the arc will be
extinguished and the entire current will pass through the incandescence body.
Dated this 22nd day of March 1899.
ABEL & IMRAY,
Agents for the Applicants.
Improvements in Electrical Incandescence Lamps.
We, SIEMENS BROTHERS & CO. LIMITED, of 12, Queen Anne's Gate, West-
minster, in the County of London, Electrical Engineers, do hereby declare the
nature of this invention (as communicated to us from abroad by Siemens &
Halske Aktien Gesellschaft, of Markgrafen Strasse 94, Berlin, in the Empire
of Germany) 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 to that kind of incandescence lamps in which a body
formed of a refractory material that is a dielectric in the cold condition (such
as oxides, mixtures of oxides, or the like) and which hereinafter we will call
the incandescence body" is in the first instance heated up to the necessary
temperature for rendering it a conductor, after which it is raised to and main-
tained in the state of incandescence by the current passed through the circuit.
In such lamps as heretofore proposed, it has been necessary to heat up the
whole of the incandescence body in the first instance for bringing the lamp into
action this being generally done by passing a sparking current directly from the
conducting socket or electrode at one end of the incandescence body to the
electrode at the other end.
Or, according to an arrangement described in Jablochkoff's Specification
No. 1996 of 1877, the incandescence body was introduced between the electrodes
of a circuit through which a high pressure current was made to pass, so that the
arc produced by such current between the electrodes heated up a portion of the
incandescence body so as to become a conductor, and the current in passing
through such part then gradually heated up the entire body to incandescence.
The present invention relates to an arrangement whereby, instead of effecting
the preliminary heating of the incandescence body along its entire length by
means of the electric arc as described in the said specification the arc is
made to pass from the one electrode in the first instance only through the part
of the incandescence body which is contiguous to such electrode, so as to heat
such portion to incandescence, after which the body is progressively heated to
incandescence along its entire length. By this means it will be seen that the
initial heating of the incandescence body can be effected by means of a current
of considerable lower pressure than is possible with the above described mode of
operating.
On the accompanying diagrammatic drawing Fig. 1 shews by way of example

page_text: a sectional elevation of an arrangement of lamp, with automatic action. Figs. 2,
to 6 shew diagrams of the action of the arc.
to be
Referring in the first place to Fig. 2, a and b represent two electrodes on an
electric circuit, between which is inserted the dielectric refractory body
heated to incandescence. At the side of these parts is arranged a conducting
rod which is in conducting connection with the upper electrode band is situated
parallel to a g b, at such a distance therefrom that an arc will be produced
between a and when a current of moderate pressure is passed through the circuit.
Owing to the well known fact that an electric arc, like every other form of
flame, tends to travel upwards the arc, once started, will gradually. ascend to the
lower end of the body y, as at Fig. 3, and will consequently cause such lower
end to be heated to incandescence, so as to become a conductor.
As the heating of g in this way gradually extends upwards, the arc will also
travel upwards to a corresponding extent, as shewn at Fig. 4, until nearly
the entire body 7 has become heated, whereupon the arc will pass from the
conductor to the upper electrode b as at Fig. 5 and, after having raised the upper
end of to incandescence, it will entirely disappear as at Fig. 6 and the body g
will then be maintained in an incandescent state by the passage of the current
from a through g to b.
In the construction of lamp operating in the above described manner shewn
at Fig. 1, the conductor which is pivotted to 6 has attached to. its upper end
the armature d of an electromagnet e the winding of which is included in the
main circuit.
When no current is passing, the conductor and armature d assume the posi-
tion shewn in the drawing, in which lower end of 7 is in contact with the lower
electrode a. On the closing of the circuit the current passes from the holder /
through electrode a and conductor to electrode b, and thence through the
electromagnete, which is thereby made to attract armature d so as to remove
from electrode a, whereupon the arc will be formed as at Fig. 2. Any too con-
siderable increase of the current before the arc is started may be prevented by
any suitable known means, such as by the introduction of a choking coil into the
circuit.
For facilitating the renewal of the incandescence body when this becomes
worn, the upper electrode bis mounted with spring action in a conducting
socket, to which conductor is pivoted. The latter may be provided with a
carbon rod for the arc to strike against; the lower electrode a may be protected
by a renewable copper cap m.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, we wish it to be understood
that we are aware that it has been previously proposed to effect the preliminary
heating of the incandescence body by means of an electric arc that is established
between the incandescence body and an electrode and is caused to travel along
the incandescence body from one end thereof to the other, and we lay no general
claim to this feature of invention, but we declare that what we claim is:-
1. In electrical incandescence lamps having an incandescence body consist-
ing of a refractory material that is a dielectric in the cold condition, the method
of effecting the preliminary heating of such incandescence body by causing the
electric current to pass in the form of sparks or an arc from the one electrode in
he first instance only through the portion of the said body which is contiguous
thereto so as to heat such part to incandescence, after which by the upward travel
of the are between the incandescence body and a stationary contiguous conductor
he current extends gradually along the whole length of the incandescence body
o the other electrode as the other portions become successively heated substan-
ially as described.
2. In an electric incandescence lamp operating as, set forth in the first claim,
he combination with electrodes such as a and b and an incandescence body

page_text: such as g, of a, conductor such as connected with the one electrode, and so
arranged that on passing a current through the lamp, an arc will first be formed
between the said conductor and the end of the incandescence body which is
contiguous to the other electrode such are afterwards travelling gradually along
the incandescence body as this becomes heated so as eventually to establish
a conducting connection with the first named electrode, substantially as described.
3. An electric incandescence lamp of the kind referred to in the first claim,
combined and operating substantially as herein described with reference to the
drawing.
Dated this 91st day of December, 1899
ABEL & IMRAY,
Agents for the Applicants.