Improvements in Regulators for Electric Arc Lamps.
Year: 1896

page_text: Date of Application, 31st Mar., 1896-Accepted, 6th June, 1895
COMPLETE SPECIFICATION.
Improvements in Regulators for Electric Arc Lamps.
1, HERMANN BÄURLIN, of Aarburg, in the Canton of Aargau, Switzerland,
Electrician do hereby declare the nature of this invention and in what manner the
sane is to be performed to be particularly described and ascertained in and by the
following statement :-
This invention relates to an improved regulator for electric arc lamps and
specially to that kind of such regulators where the regulating electro magnet is
excited by a shunt current. The arrangement provided for this purpose is fully
and clearly shown in the accompanying drawings, in which
Fig. 1 is a central vertical section of a complete arc lamp provided with the new
regulating device;
Fig. 2 is a similar section cut rectangularly to that of Fig. 1; Fig. 3 is a plan
view. Figs. 4 to 13 show details.
The cylindrical sheet metal box A is enlarged below to a reflector B and fixed
by screws a, a form to the base ring C, having a diametrically placed cross piece C³,
said ring being connected by the sheet strips C2 with the top plate D upon which
is arranged the regulating mechanism and which is covered by a cap E fixed to
the circumference of the plate D by screws e.
On the plate D is fixed a horseshoe electro magnet F whose keeper G consists
of two metallic plates 9 g, connected by stay bolts g' g' g' and a cross plate g*;
said keeper being fulcrumed between two centre screws d d supported by the
pillars d' d. This keeper has at its extremity opposite to the cores of the
magnet two soft iron pieces ff representing the proper keepers and points of
attraction; they are connected by a brass bar fhaving in its middle a rod f³
for connection with the piston ground to fit the cylinder ', which arrange-
ment forms an atmospheric brake, whilst to the other extremity of keeper G
is attached a coiled spring L fixed with its ends to the plate D and to the
bolt g' keeping the other extremity of the keeper at a distance from the electro-
magnet.
Between the side plates gg is placed a clockwork, actuated by the weight M
suspended on a cord m. This cord is carried round the larger rope pulley m' and
the smaller one m2 and then with its other end connected to the end of the rod N
guided in a sleeve C³ in the cross piece C. This rod N is the holder for the lower
carbon of the arc lamp and holds the same by a clamp N¹ provided at the end of
rod N. The top of this rod is guided by a cross head N surrounding with its
eyes n n guiding bars n³n connecting the base ring C and the plate D. In the
same manner are provided laterally of the vertical axis of the weight M to the
right and to the left the guiding bars M'M' provided for the eyes of the pins M* M*
in the weight M.
This latter forms also the clamp for the upper carbon held by the slotted elastic
tubular holder M, said carbon being guided by the insulating box M².
To the holder M and to the top of bar N are attached the insulated
conducting wires o o', these wires being also insulated with regard to the
guidings so that the electric current will be only sent into the carbons. The
wires o o' are fixed to the terminals o² o from which a shunt is derived for

page_text: the coils of the electro magnet as will be hereinafter described. This shunt
is made by the wires p p.
There is provided on the axle of rope pulley m¹ a pinion Q gearing with one of
a series of gearings, the last one having an escapement wheel Q1 which gears with
the escapement Q' fixed on the axle R, the latter being provided with a double
pendulum R'; further this axis R has a friction disc R².
To the angular cross plate g is fixed another cross plate 9 upon the horizontal
part of which is screwed a by-keeper S, composed of the strips and the soft iron
cross piece S'. The fulcrum of this keeper is no real one but a turning of the
keeper is somewhat made possible by the elasticity of the cross plate, so that an
inclination of the piece S¹ towards the pieces ff can take place, but in general this
end is at a distance from them. The other extremity of S is provided with a set
screw T whose end is pressed down upon the friction disc R³ by a set screw T¹
fixed in a support U attached to one of the side plates g.
The apparatus operates as follows:-After having clamped the carbons into the
clamps M N¹ respectively, avoiding contact of their two ends, moreover a distance
of inches between them having been provided for, the current is sent into the
two wires o o. The difference of potential between the two carbons being great
the magnetic coils will be strongly excited and a strong shunt be produced, so that
the keeper G or its ends ff will be attracted and turned around its fulcrum
points dd. Hereby the carbons are approached to another; but as the soft iron
pieces ff now form parts of the magnetic cores they will also attract the by-keeper S,
whose opposite extremity will hereby be lifted, the set screw T raised and the
friction disc R' will be released. The weight M will therefore now sink down like
an ordinary clock weight and its descending movement is exactly regulated by the
escapement and the pendulum R' above described. In the meantime the lower
carbon is raised by the clockwork and the two carbons will approach till they will
come in contact with another. The difference of potential between the carbons
will now cease and the shunt current in the magnetic coils of F also be diminished,
in consequence of which the spring L will draw back the keeper and turn it around
the fulcrum d d, and also the by-keeper S will press again with its extremity
against the friction disc R2. As by the turning of the keeper G, by the spring L,
the top carbon is raised, now an arc will appear between the carbons; but also the
difference of potential between the carbons and the shunt current are increased
again and the main keeper attracted by the magnet; but the shunt current will
not yet be strong enough to attract also the by-keeper S. Also the attraction of
the main keeper will not be a sudden one but the approachment of the keeper to
the cores will take place proportionally and gradually with the burning of the
carbons and the increase of difference of potential and of shunt current thereby
caused.
When finally the latter becomes intense enough the by-keeper is also attracted,
the clockwork is released and the distance between the carbons thereby regulated
till the difference of potential and therefore also the shunt current are diminished.
The clockwork is wound up by drawing down the carbon holder N whereby the
weight M is lifted.
It is obvions that many slight changes and alterations may be made in the parts
and combinations of parts herein before described and hence I would have it under-
stood that I do not strictly confine myself to the specific construction shown but
Having now particularly described and ascertained the nature of this said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
An electric arc lamp where the distance of the carbons is regulated by an
electro-magnet connected by a shunt circuit with the main current circuit, said
magnet having a keeper containing clockwork with pendulum escapement moved
by the weight of the top carbon clamp, the latter being suspended with a strip to

page_text: a rope pulley of the clockwork whilst the other end of said strip is attached to
the lower carbon clamp; said keeper having upon its top a by-keeper whose
extremity remote from the magnet presses against a friction wheel of the clock-
work substantially as set forth.
Dated this 31st day of March 1896.
HERBERT HADDAN & Co.,
18 Buckingham Street, Strand, London, W.C., Agents to Applicant.