Improvements in or relating to Electric Arc Lamps.
Year: 1896

page_text: Date of Application, 1st May, 1896-Accepted, 1st May, 1897
COMPLETE SPECIFICATION.
Improvements in or relating to Electric Arc Lamps.
I, CARL GRAHNER of 132 Great Frankfurterstrasse, Berlin, in the Empire
of Germany, Manufacturer, do hereby declare the nature of this invention and in
what manner the same is to be performed to be particularly described and ascer-
tained in and by the following statement :-
This invention relates to an arc lamp in which by means of a special arrange-
ment of the lever mechanism employed therein an advantageous operation of the
feed mechanism is obtained.
I will now describe the manner of carrying out the invention with reference
to the accompanying drawings in which :-
Fig. 1 is a side elevation of the apparatus.
Fig. 2 is a plan view, and
Fig. 3 is another elevation at right angles to that shown in Fig. 1.
The lamp is provided with a shunt electro-magnet a which serves to allow
the feed mechanism to act as follows:-The armature in the form of a yoke c is
adapted to enter the slots in the extremities of the poles of this magnet the
said yoke being fixed to the arms el of the bent lever e which is pivoted at d
whilst the other arme of this lever serves by means of the extensions e² and e
thereon to lock the feed mechanism by engaging the chain a as soon as the yoke
is withdrawn by means of the spring from contact with the electro-magnet.
It should be remarked that the pivot d is at a height equal to that of the
extremities of the poles of the electro-magnet and that the yoke engages in slots
in the latter thus fully utilising the surfaces of the yoke to an extent not possible
with the arrangements hitherto adopted.
On the spindle d the chain wheel fis fixed such wheel being provided with teeth
or projections thus absolutely ensuring the gearing of the connecting chain which
carries the carbon-holders g.
Attached to the lower arm of the bent lever e which is pivotted at d is a
spring which as soon as the current ceases to pass through the magnet pulls the
said lever and consequently moves the yoke out of contact with the extremities of
the poles thus causing the operation of the feed mechanism to cease.
The spring his capable of being either extended or slackened from outside the
casing of the lamp by means of the lever i and screw k so as to cause the feed
mechanism to be again brought into action by either a stronger or weaker
attraction of the yoke.
Between the pivot on which the bent lever turns and the electro-magnet a
guide is arranged in which is an air cushion (or dash pot) which regulates the
movement of the bent lever whilst the feed mechanism is braked and regulated by
means of the fly or regulator m which is actuated from the chain wheel spindle by
a train of spur gearing.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed 1 declare that what I
claim is :-
1. An arc lamp provided with a magnet a and a bent lever e (for the purpose
of controlling the feed mechanism) pivotted upon a spindle d such pivot d upon
which such bent lever turns being so located that acting in conjunction with the

page_text: slots of the extremities of the poles 6 of the magnets thereby the magnetic field
of the magnet is more fully utilised substantially as and for the purposes herein-
before described and illustrated in the drawings hereunto annexed.
2. In an arc lamp as in Claim 1 provided with a magnet a and a bent lever such
as e pivotted at d the arrangement and combination of a wheel such as provided
with projections an air break or dash pot located between the said pivot d of the
lever and the electro-magnet a and a spring such as h which can be extended or
slackened by a lever such as i and screw such as k substantially in the manner and
for the purposes herein before described and illustrated in the drawings hereunto
annexed.
Dated this 1st day of May 1896.
TONGUE & BIRKBECK,
Southampton Buildings, Chancery Lane, London, W.C.,
Agents for the Applicant.