Improvements in and relating to Reflectors for Electric Arc Lamps.
Year: 1894

page_text: Date of Application, 20th Apr., 1894-Accepted, 16th June, 1894
COMPLETE SPECIFICATION.
Improvements in and relating to Reflectors for Electric Arc Lamps.
I, CARL COERPER, of Cologne-Ehrenfeld, in the Empire of Germany, Director,
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 reflectors for electric arc lamps.
In electric arc lamps, especially those supplied by alternating currents, a
favourable illumination of areas is obtained only if a reflector is arranged
immediately above the arc. When ordinary lamp globes are used the reflector
may be made of comparatively small dimensions, because its size must depend on
the opening in the neck of the globe. The small size of the reflector materially
diminishing the effect, my aforesaid invention is designed for enabling larger
reflectors to be used also with ordinary globes and lanterns.
In the accompanying drawings,
Figures 1 and 2 are a vertical section and plan showing an electric arc lamp
provided with a globe and with my improved reflector.
The guide frame is designated by a, a, the reflector by b and the carbons by c.
As shewn, the reflector b is inside the globe. For enabling this reflector to be
introduced into the globe it is divided in a suitable manner. The guide-frame
with the carbon extends through a slit in the reflector as indicated, so that the
globe with the reflector may be moved downwards in order to insert fresh carbons.
On the lamp being closed again, that is to say when the globe is moved upwards,
the reflector will be above the arc and will thus afford an excellent means for
illuminating areas.
Figures 3 and 4 show a vertical section and plan of an arrangement adapted for
the use of a lantern. The cover of the lantern b forms a reflector, and the frame
may be pulled downwards or upwards for inserting the carbons. In this case the
arc is also as near as possible below the reflector.
The form of the slit in the reflector varies with the arrangement of the guide
frame.
In the case of lamps already provided with a small reflector on the guide frame,
I employ the arrangements represented in Figures 5, 6, 7 and 8.
In Figures 5 and 6 the reflector 6 secured to the guide frame a a is only of such
size that it will pass through the upper opening in the globe, that is to say the
upper opening in the globe c is such that the latter may be moved downwards over
the said reflector b. A reflector d d is arranged in the globe itself and may be
regarded as an addition to the reflector b secured to the guide-frame. The reflector dd
provided inside the globe may consist of any suitable number of parts according to
requirements. In this instance the active side of the small reflector fixed to the
frame is enlarged as much as the lamp globe will allow. The increase obtained by
this arrangement in the illumination of areas is very considerable, particularly with
arc lamps fed by alternating currents.
A similar arrangement of the reflectors is shown in Figures 7 and 8. The
reflector, which is fixed to the guide frame a a and can therefore more with the
lamp, is comparatively small, while the lantern cover d d forms a large reflector.
An opening is provided in the middle for introducing the guide frame so that the
small reflector fixed to the frame constitutes an addition to the fixed reflector.
When the lamp is to be provided with fresh carbons it is moved downwards or
upwards together with the guide frame a a and the small reflector b, or the carbons
are inserted through the lantern and its cap, if the lamp is stationary.

page_text: The form of the reflectors is of course quite optional and depends nearly on the
object which the reflector is to fulfil.
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 :-
"First. In combination with a globe for electric arc lamps the employment of a
reflector which, consisting of several parts and surrounding the guide frame, is
larger than the opening in the globe and placed above the arc inside this globe.
Second. In combination with a lantern for electric arc lamps the employment of
a reflector formed by the cover of the lantern and having a slit or opening for the
passage of the guide frame so that the arc may be immediately below the reflector.
Third. In combination with a globe or a lantern for electric arc lamps provided
with a small movable reflector on the guide frame immediately above the arc, the
arrangement of a large fixed reflector inside the globe or inside the lantern in such
a manner that it will constitute an addition to the small reflector adapted to move
together with the said guide frame.
Dated this 20th day of April 1894
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.