Improvements in Arc Electric Lamps.
Year: 1893

page_text: Date of Application, 21st Apr., 1893
Complete Specification Left, 10th Jan., 1894-Accepted, 10th Feb., 1894
PROVISIONAL SPECIFICATION.
Improvements in Arc Electric Lamps..
I, JAMES BROCKIE, of Fairview, Tyson Road, Forest Hill, in the County
of Kent, Engineer, do hereby declare the nature of this invention to be as
follows:
My invention relates to modifications of the regulating mechanism of arc electric
lamps of the kind described in the Specification No. 12681 of 1885. In a lamp
of this kind the cores of the two regulating solenoids which are respectively in
the main and in a shunt circuit, are independent of each other until the arc is
struck. As arranged according to the present invention they are independent of
each other to any desired extent, both before and after the arc is struck, so that
the lamp can be worked with so called constant current or constant potential on
long or short circuit.
According to my present invention 1 joint both the cores, that of the main and
that of the shunt solenoid, to a horizontal bar to the end of which farthest from
the shunt core I joint a vertical rod the lower end of which hooks under the clutch
washer that embraces the holder of the upper carbon. While the shunt core
retains one end of the bar in position, the main core lifts the middle of the bar
and the vertical rod at its end until the normal voltage between the carbons is
obtained, after which the shunt core moves the bar as a lever on the pivot by which
it is jointed to the main core thus depressing the vertical rod and releasing the
clutch washer to permit feed of the carbon..
According to a modified arrangement I pivot the horizontal bar on a fixed
fulcrum between the two cores, one end of the bar having under it the hooked end
of the shunt core, the other end being jointed to the one end of a spring, the other
end of which is jointed to the main core, this spring being of such form and length
that within the comparatively small variations of length to which it is subjected its
force remains nearly constant.
The vertical rod which hooks under the clutch washer is jointed to the bar
between its fulcrum and the attachinent of the spring, which when the main
solenoid is excited has sufficient force to raise the upper carbon and strike
the arc.
Whatever in the working of the lamp may be the force with which the main
core is attracted upwards, the maximum force opposing the shunt core is only that:
of the spring, and as this may be nearly uniform throughout the stroke of the
shunt core, the feed of the carbon takes place at uniform voltage independent of
current strength.
According to a modification, the shunt solenoid is inverted and the spring is applied
to keep its core up against the attraction of the solenoid. The horizontal bar is
jointed to the main core and to a rod extending down from the shunt core, and
between these points is jointed to it the vertical rod which hooks under the clutch
washer. In this case the arc is struck by the ascent of the main core, and the
clutch is released to permit feed when the shunt core is drawn down in opposition
to the spring.
In the ordinary working of the lamp the main core is held up against a stop, -
the shunt coil alone determining the feed of the carbon.
When it is inconvenient to invert the shunt solenoid the horizontal bar may be
arranged as a lever in two parts, the one part pivotted on a fixed fulcrum and
having its one arm jointed to the shunt core, whilst its other arm is jointed to the

page_text: one arm of the other part, the other arm of which is jointed to the main core its
middle having jointed to it the vertical rod which hooks under the clutch washer.
In this case also after the arc is struck by the ascent of the main core, which may
afterwards remain at rest against its stop, the shunt core by its ascent releases the
clutch and determines the feed.
The shunt cores employed in any of the modified arrangements above described
may be wound more or less differentially or may be. influenced differentially by
induction from polar extensions of the main solenoid.
Dated this 21ôt dan of Anvil 1902
ABEL & IMRAY,
Agents for the Applicant.
Improvements in Arc Electric Lamps.
I, JAMES BROCKIE, of Fairview, Tyson Road, Forest Hill in the County of
Kent, Engineer, 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 modifications of the regulating mechanism of arc electric
lamps of the kind described. in the Specification No. 12681 of 1885.
In a lamp of this kind the cores of the two regulating solenoids which are respectively
in the main and in a shunt circuit, are independent of each other until the arc is
struck. As arranged according to the present invention they are independent of
each other to any desired extent, both before and after the arc is struck, so that
the lamp can be worked with so called constant current or constant potential on
long or short circuit.
The accompanying drawings illustrate arrangements of lamps according to my
present invention.
As shewn in Figs. 1, 2 and 3 I joint both the solenoid cores, that of the main
solenoid A and that of the shunt solenoid B to a horizontal bar C to the end D of
which farthest from the shunt core B I joint a vertical rod E the lower end of which
hooks under the clutch washer F that embraces the holder G of the upper-
carbon H. When no current is passing, the cores rest on hooks or stops K which
determine their lowest position.
While the shunt core B retains one end of the bar C in position, the main
core A when the current passes lifts the bar and the rod E as shewn in Fig. 2,
until the normal voltage between the carbons is obtained, after which the shunt
core moves the bar C as a lever on the pivot L by which it is jointed to the main
core A thus depressing the rod E and releasing the clutch washer F to permit feed
of the carbon, as shewn in Fig. 3, both cores being in this condition attracted up
from their stops K.
The movements are preferably moderated by a dash pot P the piston of which
is linked to C.
The main solenoid may or may not be arranged to affect the potential at which
the shunt coil permits release of the feed mechanism. If it be desired that the
main solenoid should not affect the regulation or feed after it has separated the
carbons, a stop may be provided for the core A in its highest position, against
which it would be held as long as the main current is strong enough to support it.
If, however, it be desired that the main solenoid should play some part in regulating
the feed, then its core A may have applied to it a weight or spring so adjusted
that, as the main current varies in strength, the core A takes a higher or lower.

page_text: position, and the shunt core B has to travel through a greater, or less distance in
order to permit the feed.
According to a modified arrangement shewn in Fig. 4, I pivot the horizontal
bar C on a fixed fulcrum M between the two cores A and B one end of the bar
having under it the hooked end N of the shunt core B, the other end being jointed
to the one end of a spring S the other end of which is jointed to the main core A,
this spring being of such form and length that, within the comparatively small
variations of length to which it is subjected, its force remains nearly constant.
The vertical rod E, which hooks under or is jointed to the clutch washer F, is
jointed to the bar C at any convenient point between its fulcrum Mand the
attachment of the spring S which, when the main solenoid is excited has sufficient
force to raise the upper carbon and strike the arc.
Whatever, in the working of the lamp, may be the force with which the main
core A is attracted upwards, which may be of a sudden and violent character, the
maximum force, opposing the shunt core B or lifting the carbon, can only be that
of the spring S, and, as this may be nearly uniform throughout the stroke of the
shunt core, the feed of the carbon takes place at uniform voltage independent of
current strength.
As shewn in Fig. 5 a weight W is substituted for the spring.
The spring or its equivalent may be placed directly between the main core A
and the clutch mechanism as shown in Fig. 8.
A spring may also be used as shewn in Fig. 9 in lamps having only one core A'
of a solenoid having its coil traversed by the main current or differentially wound
with coils traversed by both main and shunt currents so that, whatever may be the
force with which the main core is attracted upwards, the maximum force in lifting
the carbon is only that of the spring.
According to a modification shewn in Fig. 6 the shunt solenoid is inverted and a
spring S¹ is applied to keep its core B' up in opposition to the attraction of the
solenoid. The horizontal bar C is jointed to the main core A and to a rod Q
extending down from the shunt core, and between these points is jointed to it the
vertical rod-E which hooks under or is jointed to the clutch washer F.
In this case the arc is struck by the ascent of the main core A. and the clutch F
is released to permit feed when the shunt core B' is drawn down in opposition to
the spring St.
The main core A may have a stop determining its maximum ascent so that the
shunt solenoid alone will control the feed of the carbon.
When it is inconvenient to invert the shunt solenoid the arrangement shewn in
Fig. may be adopted. In this case the horizontal bar is modified, taking the
form of a lever in two parts, the one part C¹ pivotted on a fixed fulcrum and
having its one arm jointed to the shunt core B whilst its other arm is jointed to
the one arm of the other part C' the other arm of which is jointed to the main
core A its middle having jointed to it the vertical rod E which hooks under the
clutch washer F. In this case also, after the arc is struck by the ascent of the
main core A, which may afterwards remain at rest against a stop R above,
the shunt core B, by its ascent, releases the clutch F and determines the feed.
The shunt cores employed in any of the modified arrangements above described
may be wound more or less differentially or may be influenced differentially by
induction from polar extensions of the main solenoid as indicated by the dotted
lines T in Fig. 5, shewing a piece of iron having end parts projecting into the two
solenoids.
Although, for the sake of clearness, I have shewn in the drawings a clutch
washer F controlling the carbon, the link or rod E may obviously be connected to
other known brake or hindering devices used in are electric lamps.
For the solenoids and cores may be substituted electro magnets and armatures,
and, with suitable modifications, the arrangements of the solenoids and levers may
be inverted as illustrated for example by Fig. 7 which shows inversion of the
arrangement shewn in Fig. 6.

page_text: :
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 in respect of the regulating mechanism of arc electric lamps, is :-
1. Connecting both the cores of the main and shunt solenoids to a bar or
Jever connected to the feed clutch or its equivalent, substantially as described
with reference to Figs. 1, 2 and 3, or in the modified forms 'illustrated by Figs. 6
and 7..
L
:
2: Connecting the bar or lever referred to in the preceding claim, not directly
to the main core, but through an interposed spring or. weight, substantially as
described with reference to Figs. 4 and 5, or in the modified forms illustrated in
Figs. 8 and 9.