Improvements in Electric Arc Lamps.
Year: 1898

page_text: Date of Application, 29th July, 1898-Accepted, 25th Mar.,
1899
COMPLETE SPECIFICATION.
Improvements in Electric Arc Lamps.
I, HUGO BREMER, of Neheim on the Ruhr, in the Empire of Germany, Manu-
facturer, 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:-
For the purpose of obtaining a greater useful effect in arc lamps by using,
instead of one pair of carbons, two or more pairs, and also with the object of
better distributing the light, it is of advantage to arrange the pairs of carbons
in such a manner that they shall be capable of being regulated by the principal
pair of carbons, that is to say, by connecting the first pairs to the said principal
pair, or by providing a special regulation for each pair of carbons.
The pairs of carbons may be included in the same circuit, or each pair may
have a separate circuit. This arrangement is particularly suitable, as has been
shewn by experience, in lamps having an arc of great extent, because the dis-
tance of the carbons is, in this case greater, and because, in consequence, if one
of the carbons is consumed more quickly than the others the arc will not become
diminished thereby, but will, by reason of the increase in the distance, and con-
sequently in the resistance, allow only a slight current to pass; therefore, the
carbon passed through by this current will become consumed less quickly. To
start the lamp it is necessary that all the carbons shall come in contact. in conse-
quence of the contact of the main pair of electrodes. This is effected by mount-
ing one or more of the pairs of carbons upon springs in such a manner that they
are capable of yielding in the direction of their length in case one or the other
of the carbons should be a little longer than the other. The main pair of car-
bons will therefore, be in contact only when all the other carbons are also in con-
tact, and the latter will only be separated when the circuit has been closed by
the main pair of carbons. In any case whether they are regulated together or
separately, the arrangement of placing several pairs of carbons together in one
lamp has many advantages. Firstly, the light of two or three arcs will pass
through the glass globe, and if, at any moment. one arc should be irregular or
fluctuate, such irregularity will be compensated by the constancy of the other
arcs; this is very necessary for lamps with a large arc. Secondly the heat of
one arc is favourable to the other arc. The carbons burn in a hotter medium
than in lamps having only one arc. The resistance is thereby diminished and
the efficiency of the lamp becomes greater. Thirdly, it has been found that
three small lamps will produce more light than one single lamp which receives
the same amount of current as 'the three small lamps together.
This arrangement is specially employed for lamps of long are produced by the
admixture of metallic salts to the carbons. In this case the carbons must be
arranged in a vacuum because the said are has but little stability: the combina-
tion of several pair of carbons will have the result of compensating the irregulari-
ties and a more steady light will be produced,
With the same object, in lamps having a long arc, carbons having an annular

page_text: cylindrical form in cross section are employed. The direction of the arc which
remains at the periphery is then ensured, and the light is then more regular.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
(1) An arc lamp having several arcs, characterised by one or more pairs of
carbons adjoined to the main pair of carbons in the same lamp globe and burn-
ing together and being connected with the said latter pair in such a manner that
all the pairs of carbons are regulated separately or by the same regulating device,
the different adjoined parts of carbons being capable of being included in the
same circuit, or each of said pairs may be fed by
a separate cir-
cuit; the adjoined carbons being mounted on springs in those cases
where one or the other of said carbons shall be longer than the others, so as to
allow the said longer carbon to yield in the direction of its length and thus allow
(when the lamp is lighted) of the contact of the two main carbons taking place
between the same, when all the adjoined carbons have come in contact; and. the
pairs of carbons so acting that the heat of one are will influence the other arc,
as set forth.
(2) For lamps having a long are produced by the admixture of metallic salts
to the carbons or by the arrangements of the carbons in a vacuum, forming the
carbons in the form of hollow cylinders for the purpose of producing an
which shall be constantly at the periphery, substantially as hereinbefore
described.
arc
Dated this 29th day of July 1898.
ROBERT E. PHILLIPS, Assoc.M.Inst.C.E., M.I. Mech. E.,
Chartered Patent Agent, 70, Chancery Lane, London, W.C.,
Associate Agent.