Improvements in Electric Aro. Lamps.
Year: 1891

page_text: Date of Application, 8th Oct., 1891
"
Complete Specification Left, 2nd Nov., 1891-Accepted, 5th Dec., 1891
PROVISIONAL SPECIFICATION.
Improvements in Electric Aro. Lamps.
I, JOHN HALL RIDER, .of The Northern Telegraph Works, Halifax, Yorks.,
Electrical Engineer, do hereby declare the nature of this invention to be as
follows:
When are lamps are burned from supply mains having a difference of potential.
of from 100 to 120 volts, it is customary and convenient to join two lamps in series
and place each pair in a "derived" or "shunt" circuit. with a small regulating
resistance. It frequently happens, however, that only one, lamp is required and
then a large resistance has to be interposed in the branch which absorbs the power
that would otherwise be required by the second lamp. Thus one lamp can only be
supplied at the expense. of the energy required by two and so at a great loss.
By this invention however one lamp only is required for each branch with the
usual small resistance. The light given by this one lamp can be made practically
equal to that given by the ordinary single lamp and the power consumed is also
the same.
In carrying out this invention I employ two arcs, but only one case, and one
globe or lantern, and thus practically only one lamp. The ordinary "double
Carbon" arc lamp is an example of this but differs from this invention in the
important respect that whereas in the "double carbon" damp the one pair of
carbons does not burn until the other pair is finished, in the lamp constructed
according to this invention both pairs of carbons burn at the same time, and the
one pair is connected in series with the other pair.
In order that this "double" lamp may not give more light than the ordinary
single lamp it may be constructed to burn with, a much smaller current. For
example, if a "double" lamp were required to give a light approximately equal to
that of an ordinary single lamp taking 10 amperes, I construct the same to take
..only say 5 amperes and so obtain two arcs of 5 amperes each, in one lamp against
one arc of 10 amperes in the other. The power consumed in the two lamps would
be the same, for if each are required 50 volts the "double" lamp would take
50 x 2.x 5500 watts and the single lamp would take 50 × 1 × 10 = 500 watts
Blso.
Each pair of carbons has its own regulating mechanism and coils. Any ordinary
type may be used for this but I prefer to use the combinations described in Letters
„Patent No. 17652 year 1889 granted to me. This however is not by any means
essential to the successful working of the invention.
As the two arcs are in series and burn quite independently it is necessary that the
rods carrying the carbons should be efficiently insulated from each other and from
the framework of the lamp. In order to minimise the difficulties of this 'I may
Construct the lamp so that the mechanism of the one pair of carbons acts upon the
negative or lower carbon rod or holder of that pair while the mechanism of the
..other pair acts upon the positive or upper carbon rod or holder of its pair. As
the negative carbon of the one pair is necessarily joined to the positive carbon of
the other this connection can conveniently be made through the frame of the lamp
and thus the regulating mechanism need not be insulated from the frame in any
Wey. It is necessary however in this case that the two terminals of the lamp and
5 the remaining two carbon rods or holders should be efficiently insulated from each
other and from the frame of the lamp.
The two main circuit coils can be joined in series with each other and the carbons
in the usual way, while the two shunt or "bye-pass" coils are joined each as a shunt

page_text: An arc lamp may be constructed in this manner with more than two pairs of
carbons to burn from circuits having a still higher difference of potential.
Dated this 7th day of October 1891.
JOHN H. RIDER.
COMPLETE SPECIFICATION.
Improvements in Electric Arc Lamps.
JOHN HALL RIDER Northern Telegraph Works Halifax Electrical Engineer,
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 :-
When arc lamps are burned from supply mains having a difference of potential
of from 100 to 120 volts, it is customary and convenient to join two lamps in series
and place each pair in a "derived" or "shunt" circuit with a small regulating
resistance. It frequently happens however that only one lamp is required and then
a large resistance has to be interposed in the branch which absorbs the power that
would otherwise be required by the second lamp. Thus one lamp can only be
supplied at the expense of the energy required by two and so at a great loss.
By this invention, however one lamp only is required for each branch with the
usual small resistance. The light given by this one lamp can be made practically
equal to that given by the ordinary single lamp and the power consumed is also
the same.
"
In carrying out this invention I employ two arcs, but only one case and one
globe or lantern, and thus practically only one lamp. The ordinary "double
carbon arc lamp is an example of this, but differs from this invention in the
important respect that whereas in the "double carbon" lamp the one pair of carbons
does not burn until the other pair is finished, in the lamp constructed according to
this invention both pairs of carbons burn at the same time, and the one pair is
connected in series with the other pair.
In order that this "double" lamp may not give more light than the ordinary
single lamp it may be constructed to burn with a much smaller current. For
example if a "double" lamp wero required to give a light approximately equal to
that of an ordinary single lamp taking 10 amperes I construct the same to take
only say 5 amperes and so obtain two arcs of 5 amperes each in one lamp against
one arc of 10 amperes in the other. The power contained in the two lamps would
be the same, for if each are required 50 volts the "double" lamp would take
50 x 2 x 5 = = 500 watts and the single lamp would take 50 × 1 × 10=
also.
500 watts
Each pair of carbons has its own regulating mechanism and coils. Any ordinary
type may be used for this, but I prefer to use the combinations described in Letters
Patent No. 17652 year 1889 granted to me. This however is not by any means
essential to the successful working of this invention.
As the two arcs are in series and burn quite independently it is necessary that
the rods carrying the carbons should be efficiently insulated from each other and
from the frame work of the lamp. In order to minimise the difficulties of this I
may construct the lamp so that the mechanism of the one pair of carbons acts upon
the negative or lower carbon rod or holder of that pair while the mechanism of the
other pair acts upon the positive or upper carbon rod or holder of its pair. As
the negative carbon of the one pair is necessarily joined to the positive carbon of
the other this connection can conveniently be made through the frame of the lamp
and thus the regulating mechanism need not be insulated from the frame in any
way. It is necessary however in this case that the two terminals of the lamp and
the remaining two carbon rods or holders should be efficiently insulated from each
other and from the frame of the lamp.
The two main circuit coils can be joined in series with each other and the

page_text: carbons, in the usual way while the two shunt or "bye pass" coils are joined each
as a shunt or "bye pass" to its own arc.
An arc lamp may be constructed in this manner with more than two pairs of
carbons to burn from circuits having a still higher difference of potential.
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 =
In electric arc lamps the use of two or more pairs of carbons in the one lamp the
said pairs of carbons being connected in series with each other and arranged to
burn at the same time substantially as described.
Dated this 31st. dex of October 1891:
JOHN H. RIDER.