Year: 1888

page_text: Date of Application, 8th Feb., 1888
Complete Specification Left, 8th Nov., 1888
Complete Specification Accepted, 21st Dec., 1888
1, ARTHUR JAMES HOWES of No. 2 Milman Place, Bedford Row in the County of
Middlesex, Electrician do hereby declare the nature of this invention to be as
follows:-
My invention relates to means of automatically regulating the distance of the carbons
of an arc electric lamp, the objects which I have in view being simplicity and cheap-
ness of construction and certainty of action. For this purpose, I attach the upper
carbon holder to a tube of non magnetic material which is free to slide vertically
within a fixed solenoid, this solenoid being wound with two coils, one of low resistance
in the main circuit of the lamp and another of high resistance in a shunt from the
lump circuit, connected in such a way that the current in the latter coil is opposed to
the current in the former. Within the tube that can slide in the solenoid are two
semicylindrical pieces of soft iron which hanging side by side nearly fit the tube but
are magnetically insulated from each other by facing with paper or other suitable
material their flat faces. These pieces are connected by cords or chains passing over
pullies to the lower carbon holder, with such additional weights as may be necessary
for nearly balancing the system. The action of the lamp is a follows. Assuming the
two carbons to be in contact, the iron pieces in that case extending some distance
below the solenoid, then almost the whole current passing through the low resistance
coil excites the solenoid so that the two pieces of iron are magnetised and also attracted
upwards. Being magnetised with the same polarity they repel each other laterally
and so press on the tube enclosing them that they have sufficient frictional hold to
move the tube along with them. Being attracted upwards they raise the tube and
thus separate the carbons till the arc is struck. As the carbons by consuming become
farther separated, so that the arc acquires excessive resistance, the main coil of the
solenoid and the shunt coil neutralise each other, the iron pieces become more or less
demagnetised and lose their frictional hold of the tube which descends bringing the
carbons near to each other.

page_text: Thus according as the resistance of the arc varies, the iron pieces operate to raise or
to let go the tube, the result being that the distance of the carbons is maintained nearly
uniform.
Dated this 8th day of February 1888.
ABEL & IMRAY,
Agents for the Applicant.
1, ARTHUR JAMES HOWES, of No. 2 Milman Place, Bedford Row, in the County of
Middlesex, Electrician, 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 :-
My invention relates to means of automatically regulating the distance of the carbons
of an arc electric lamp, the objects which I have in view being simplicity and
cheapness of construction and certainty of action.
For this purpose, I construct the lamp as shewn partly in vertical section by Fig. 1
of the accompanying drawings.
I attach the upper carbon holder A to a tube B of non magnetic material which is
free to slido vertically within a fixed solenoid C, this solenoid being wound with two
coils, one of low resistance D in the main circuit of the lamp and another E of high
resistance in a shunt from the lamp circuit connected in such a way that the current in
the latter coil E is opposed to the current of the former ]).
Within the tube B are two semicylindrical pieces F F¹, as shown in the sectional
plan Fig. 2, of soft iron which hanging side by side nearly fit the tube B but are
magnetically insulated from each other by facing with paper or other suitable
material their flat faces which may be recessed as shewn throughout a great part of
their length.
These pieces FF1 are suspended by a wire or rod G having its end pin in a slotted
holo at the top of the lamp.
The action of the lamp is as follows:-
Assuming the two carbons to be in contact, the iron pieces F F¹ in that case
extending some distance below the solenoid C then almost the whole current passing
through the low resistance coil D oxcites 'the solenoid so that the pieces F F¹ aro
magnetised by induction and also attracted upwards.

page_text: Being magnetised with the same polarity they repel each other laterally and so
press on the tube B enclosing them that they have sufficient frictional hold to move
the tube along with them.
Being attracted upwards they raise the tube B and thus separate the carbons till
the arc is struck. As the carbons by consuming become farther separated so that
the arc acquires greater resistance, less current passes through the coil D and more
through the coil É and as these are in opposite directions, they neutralise each other
rendering the solenoid inert.
Thus the iron pieces F F¹ become more or less demagnetised and lose their
frictional hold of the tube B which being then left free descends bringing the upper
carbon nearer to the lower carbon.
Thus according as the resistance of the arc varies the iron pieces F F' operate
to raise or to let go the tube, the result being that the distance of the carbons is
maintained nearly uniform.
The arrangement above described of solenoid with two coils is necessary when
several lamps are connected in series, the high resistance coil of each completing
the general circuit when the circuit through the carbons is opened. When however
only one lamp is used or several lamps connected parallel, this high resistance coil
is unnecessary. In such cases therefore the solenoid need have only one coil of low.
resistance in the circuit of the lamp.
When owing to too great distance of the carbons the resistance of the arc becomes
excessive, the solenoid Yoses attractive power and the core descends bringing the
carbons nearer together.
Instead of using a divided core with a non-magnetic tube, the arrangement shewn
in Fig. 3 may be adopted. In this case the tube B is of iron and the iron core F
need not be divided and may be tubular. When the core is attracted upwards it,
as well as the tube, are magnetised, and the core takes such a position that it has a
hold of the tube causing it to move with it.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I'
claim is :-
.
1. The herein described method of regulating the carbons of an electric arc lamp by
the inductive and attractive action of a solenoid on an iron core suspended within a
tube carrying the upper carbon, causing this core to frictionally hold the tube while
it ascends and leaving the tube free to descend when the solenoid is inert.
2. In combination with a non magnetic tube carrying the upper carbon of an arc
electric lamp a solenoid surrounding the tube and a divided iron core within the tube,
arranged and operating substantially as described.
3. In combination with a magnetic tube carrying the upper carbon a solenoid
surrounding the tube and an iron core, within the tube, arranged and operating
substantially as described.
Dated this 8th day of November 1888.