Improvements in Electric Arc Lamps.
Year: 1894

page_text: Date of Application, 20th Sept., 1894
Complete Specification Left, 20th June, 1895-Accepted, 24th Aug., 1395
TROVISIONAL LEIVATION.
Improvements in Electric Arc Lamps.
I MICHAEL IMMLER of No. 3 Fyues Street Vincent Square Westminster
London Electrical Instrument Maker do hereby declare the nature of this invention
to be as follows:-
This arc lamp consists of a break-wheel connected by chain or rack to the carbon
holders, which said break wheel is operated by an excentric forming the break and
release. The said excentric is pivotted to a lever and said lever is worked by the
controlling magnet or solenoid. When striking the arc the excentric works as
a clutch. For the motion of the feed the said excentric is provided with a lever
and soft iron armature, the latter being attracted by a shunt magnet, thus releasing
the wheel and feeding the carbons. This lamp can be used both with continuous
or alternating current, also in parallel or in series.
Dated this 20th day of September 1894.
I, MICHAEL IMMLER, of 3, Fynes Street, Vincent Square, Westminster, in the
County of Middlesex, Electrical Instrument Maker, 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 arc lamps and comprises the improvements hereinafter
indicated.
The chief feature of my invention relates to the feeding mechanism and consists
in the provision of a disc pivoted excentrically for controlling the brake wheel which
rotates when the lamp feeds. The application of this disc to the periphery of the
brake wheel is controlled by an electro-magnet which is included in a shunt on
the arc.
In order that my invention may be readily understood I will now proceed to
describe the same with reference to the accompanying drawing in which
Figure 1 is an elevation of my improved arc lamp unimportant parts being
broken away to shew the construction more clearly,
Figure 2 is a plan shewing a detail.
A is the base of the lamp which supports the mechanism, B the frame
forming the guides for the carbon holders C, D. E is a solenoid in series with
the arc which causes the "striking of the arc to take place, F is an electromagnet
included in a shunt on the arc which regulates the feed.
"
The carbon holders C, D are connected by a pitch-chain G which passes over
a pinion G¹ secured on a spindle G2 which is supported on bearings in brackets
secured to the base A. The lamp is therefore approximately self-focussing. On
the spindle G2 is also secured the brake wheel G³ with the periphery of which
a brake can engage as hereinafter described.

page_text: H is a frame which is provided with hollow trunnions H₁ through which the
spindle
G* passes without touching, said trunnions are pivoted in. brackets fixed to
the base A in any suitable manner. The brake disc I is excentrically pivoted at I'
in the frame H and an arm 12 is secured thereon which is connected by a spring
clip J with the armature F¹ of the shunt electromagnet F. The said armature
as shewn in Fig. 2 is carried on a spring F2 which tends to overcome the
attraction of the magnet ou the armature. The brake disc I is so arranged
that as long as the armature F' is not attracted the periphery of the brake
wheel G3 is pressed upon by the disc I, when however the armature F¹ is attracted
by its magnet it operates through the clip J to turn the disc on its pivot and
relieve the pressure on the brake wheel..
The end of the frame H supports the iron core E¹ of the solenoid E by means
of pins E² in said core, and the said frame, on which the shunt coil F is carried
as shewn, is so weighted that when the core E' is lifted the frame turns on its
trunnions H in the direction of the arrow until an adjustable stop H2 comes in
contact with the base plate A, the amount of movement of the frame H does not
therefore depend on the height to which the core E¹ is lifted as said core simply
rests on the frame and is not rigidly connected therewith. I sometimes provide
a suitable spring which presses the core E' downwards against the attraction of
the coil E.
The electrical circuits are as follows. The current enters at the terminal A¹
insulated from the base A and then divides passing by flexible lead C₁' to upper
carbon C2 and through the arc to carbon D'. Thence the current flows by flexible
lead D2, insulated wire B' which passes through the side rod B, to the series coil E
and through said series coil to terminal A². In the other branch of the circuit the
current passes from terminal A' through the shunt coil F to the positive terminal
of the series coil E so that the coil F shunts the arc.
The operation of my improved are lamp is very simple and is as follows:-As
soon as the current is switched on, if the carbons are not already in contact the
current passes through the shunt coil F and as above described, by the agency
of armature F', clip J and arm I relieves the brake wheel, G³ of the pressure
of the disc I. The spindle G2 and pinion G¹ are therefore free to turn and the
upper carbon holder being the heavier, descends pulling up the lower carbon
holder by the chain G and bringing the carbons together. The shunt coil is
short-circuited by the are and the armature F¹ being no longer attracted causes
the disc I to press on the periphery of the brake wheel G³, at the same time the
series coil E being energized draws up the core E' and relieves the frame H of
the weight thereof. The frame H then turns on its trunnions H in the direction
of the arrow and the disc I pressing on the periphery of the wheel G³ rotates the
same drawing the carbons apart and striking the arc.
As the resistance of the arc grows larger with the increase in its length the shunt
coil F is energized and attracts its armature F¹ this turns the disc 1 on its pivot
and allows the brake wheel to turn and the lamp feeds.
The carbons can readily be separated for trimming as the lowering of the bottom
carbon holder turns the brake wheel G³ in such a direction as to relieve the
pressure of the excentric disc I against it. The carbons can not however approach
each other until the armature F¹ is attracted since the rotation of the brake wheel
is then in an opposite sense and the disc I is thereby caused to press more tightly
against the same.
By my improved device of an excentrically pivoted brake disc a very delicate
feed of the carbons is produced and the lamp therefore burns very steadily without
flickering.
My improved. arc lamp can be arranged for use with direct currents or with
alternating currents the usual precautions being taken in the latter case to laminate
the iron cores of the electromagnets. It may also be used in either a parallel or
a series system of lighting that is to say it will run on either a constant potential or
a constant current.

page_text: 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 :-
1. In an arc lamp in which the feeding of the carbons is controlled by a brake
wheel, a brake for said wheel consisting of a disc pivoted excentrically and operated
by an electromagnet shunting the arc, substantially as described.
2. In an arc lamp, a frame pivoted concentrically with the brake wheel and
carrying the brake therefor, which frame supports the core of a coil in series with
the arc and is so weighted that when relieved of the weight of the core it rocks and
rotates the brake wheel so as to strike the arc, substantially as, and for the purpose,
specified.
3. An arc lamp constructed and operating substantially as described with
reference to the accompanying drawing.
Dated this 20th day of June 1895.
W. P. THOMPSON & Co.,
31, High Holborn, London, W.C., Patent Agents for the Applicant.