this means a
5 slight tendency given swingthe armature
toward the pole-piece the main magnet. this case the arc reaches a
great length, until finally breaks.
This cut-out operates follows: When, upon
a failure the feed, the arc reaches certain
predetermined length, such amount cur
rent diverted through the fine wire that the
polarity the compound magnet reversed. Then the
light goes out, and frequently the fine wire is
injured.” The
whole the soft-iron parts m', n', and
L form compound magnet.
20 The wire the main magnet consists two
parts, %
' and p'.
This switch ofordinary character, and not
shown the drawings.
It occurs often practice that the rod sticks
in the guides. The part being
normally circuit, is, with the fine wire upon
25 the shunt-magnet, wound and traversed the
current the same direction, tend to
produce similar poles, the cor
responding pole-pieces the magnets and
FT. and fastened the top plate, B,
and hooked the lever The hook to
ward one side the lever bent little
sidewise, seen Fig. This clamping and re
leasing the rod continues until the carbons
are consumed. 1. The part only circuit when the
30 lamp cut out, and then the current being in
the opposite direction produces the main
magnet magnetism the opposite polarity. prevent such accident, pro
vide lamp with automatic cut-out. The fine wire now re
ceiving less current, the magnetism increases,
and the rod clamped again and slightly
raised, necessary. pulling down the arma
ture-lever the main magnet assisted by
the shunt-magnet FT
, the latter being mag
netized magnetic induction from the mag-
50 net M.
The binding -posts are preferably
screwed the base manual switch, for
short-circuiting the lamp when the carbons
io are renewed, also fastened the base.
The carbons being separated, the fine wire
60 receives portion the current. soon the contact estab
lished, the current passes from the positive
binding-post over thed armature g,
insulated shunt-magnet, and the helix upon
the main magnet the negative binding-
post.
It will seen that the armatures and g
are practically the keepers for the magnets M
and FT
, and owing this fact both magnets
with either one the armatures Land may
55 considered one horseshoe-magnet,which
we might term compound magnet. During the
normal operation the lamp the armature-
lever remains stationary, nearly so, in
the position shown Fig.
The operation follows: the start the
carbons are contact, and the current
35 passes from the positive binding-post the
lamp-frame, carbon-holder, upper and lower
carbon, insulated return-wire one the
side rods, and from there through the part of
of the wire the main magnet the nega-
40 tive binding-post.
As the carbons burn away, the fine wire re1
ceives more current and the magnetism di
minishes proportion. This causes the arma
ture-lever swing and the armature to
descend gradually under the weight the
moving parts until the end Fig.335,787
Figs.
Should arise that, owing imperfec
tion the rod, the same and the carbons drop
too far, make the arc too short, even
bring the carbons contact, then very small
amount current passes through the fine wire,
and the compound magnet becomes sufficient
ly strong act the start pulling the
armature-lever down and separating the
carbons greater distance.
85
90
95
100
!OS
110
ri5
120
!25
130
. 7. These two parts may in
two separated coils one single helix, as
shown the drawings. practice the feed sen
sitive that for the greatest part the time the
movement the rod cannot detected with
out some actual measurement.
Theclamping-armature^ nowmoved against
the shunt-magnet FTuntil strikes the releas
ing-pole n'. The lamp-case receives re
movable ornamental cover, s‘, around the samé
to inclose the parts. FTow, the
■magnetic induction from the magnet such
as produce opposite poles the corre
sponding ends the magnet if; but the cur
rent traversing the helices tends produce
65 similar poles the corresponding ends of
both magnets, and therefore soon the fine
wire traversed sufficient current the
magnetism the whole compound magnet is
diminished. this case the current passes the
opposite direction and changes the polarity of
the magnet the same time maintaining
by magnetic induction the core shunt-
magnet the required magnetism without re
versal polarity, and the armature remains
70
75
80 . Upon the passage the
current the main magnet energized and at
tracts the clamping-armature swinging the
clamp and gripping the rod means the
gripping-jaws the same time the ar-
45 mature-lever pulled down and the car
bons separated. strikes
-a-stop the top plate, The adjustment is
such that when this takes place the rod is
yet gripped securely the jaws The
further downward movement the armature-
lever beiDg prevented, the arc becomes longer
as the carbons are consumed, and the com
pound magnet weakened more and more
until the clamping -armature releases the
hold the gripping-jaws upon the rod R,
and the rod allowed drop little, short
ening thus the arc.
The electrical connections are indicated
diagrammatically Fig.
The rod electrically connected the
lamp-frame means flexible conductor
£5 otherwise.
With regard the armature and the Op
eration the lamp, the pole may termed
as the clamping” and thepole the “re
leasing” pole
