Improvements in Electric Are Lamps.
Year: 1895

page_text: Improvements in Electric Are Lamps.
I WILLIAM JAMES DAVY, of 161 Huddleston Road, Tufnel Park, in the
County of Middlesex, Engineer; do hereby declare the nature of this invention to
be as follows:-
This invention for improvements in electric arc lamps relates to focussing lamps
in which the positive and negative carbon holders are connected together by a
chain or cord passing. over a pulley and in which the upper carbon holder tends
to descend by gravity and thus at the same time to draw up the lower carbon
holder so as to bring the two carbons into contact; and consists in an improved
arrangement for striking and maintaining constant the arc and in improved
means for adjusting the lamp according to the potential of the circuit in which it
is to work.
In an electric arc lamp constructed according to this invention, the carbon holders
are connected together by a chain passing over a pulley and having a deep flange
or lip. A nipping lever having at one end a notch fitting loosely the flange or lip
is pivotted at its other end on a spindle mounted at right angles to the nipping
edges. Means are provided for determining the position of the lever pivot
according to the resistance of the lamp, the motion being limited by suitable etops.
In its normal position when no current is passing through the lamp the nipping
lever rests on a stop, the carbons being in contact. When the current is passed
into the lamp, the pivotted end of the lever is raised to cause its notch to grip;
the flange or lip and then it is raised bodily to strike the arc. As the arc
increases in length the lever is lowered so that the free end comes against its
stop, and then as the pivot is further lowered the lever gradually releases the flange.
or lip and allows the carbons to feed together.
:
In one form the pulley is loose on its spindle and the nipping lever is pivotted.
to a frame itself pivotted loosely, on the spindle of the pulley and connected to a
rocking, frame carrying at its opposite sides the cores of the usual regulating.
solenoids. A weight is arranged to slide lengthwise of the rocking frame to.
regulate the lamp.
ابة
A cut out for the lamp consists of two carbon blocks one fixed. and the other
attached to: a. sliding. armature, adapted to be: operated by the arc striking
solenoid.
Dated this 18th day of January 1895.

page_text: Improvements in Electric Arc Lamps.
I WILLIAM JAMES DAVY, late of 161 Huddleston Road, Tufnel Park but
now of 4 Parolles Road, Holloway, in the County of Middlesex, 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 :-
This invention for improvements in electric arc lamps relates to focussing lamps
in which the positive and negative carbon holders are connected together by a
chain or cord passing over a pulley and in which the upper carbon holder tends to
descend by gravity and thus at the same time to draw up the lower carbon holder
so as to bring the two carbons into contact; and consists in an improved arrange-
ment for striking and maintaining constant the arc and in improved means for
adjusting the lamp according to the potential of the circuit in which it is to
work.
In an electric arc lamp constructed according to this invention the carbon holders
are connected together by a chain or cord passing over a pulley and having a deep
flange or lip. A nipping lever having at one end a notch fitting loosely the flange
or lip is pivoted at its other end on a spindle mounted parallel to the nipping
edges. Means are provided for determining the position of the lever pivot
according to the resistance of the lamp, the motion being limited by suitable stops.
In its normal position when no current is passing through the lamp the nipping
lever rests on a stop, the carbons being in contact. When the current is passed
into the lamp the pivoted end of the lever is raised to cause its notch to grip the
flange or lip and then it is raised bodily to strike the arc. As the arc increases in
length the lever is lowered so that the free end comes against its stop and then as
the pivot is further lowered the lever gradually releases the flange or lip and allows
the carbons to feed together.
.
In one form the pulley is loose on its spindle and the nipping lever is pivoted to
a frame itself pivoted loosely on the spindle of the pulley and connected to a
rocking frame carrying at its opposite sides the cores of the usual regulating
solenoids. A weight is arranged to slide lengthwise of the rocking frame to regulate
the lamp.
A cut out for the lamp consists of two carbon blocks one fixed and the other
attached to a sliding armature adapted to be operated by the arc striking
solenoid.
In the accompanying two sheets of illustrative drawings:
Fig. 1 is a front elevation of a single arc lamp constructed according to this
invention Fig. 2 is a side elevation of the upper part of the lamp, and Fig. 3 is a
plan of the same.
:
Figs. 4, 5 and 6 are similar views to Figs. 1, 2 and 3 showing the upper part of
a duplex lamp and Fig. 7 is a detail view of a cut out.
Referring to Figs. 1, 2 and 3 the upper carbon traveller a is guided on the two
parallel rods b and the lower carbon holder c is attached to the tail rod d secured
to the traveller e guided on the two parallel rods f. The two travellers a and e are
connected together by a chain 9 passing over the pulley h mounted loosely on the
spindle fixed in the saddle bracket / secured to the base disc m.
The pulley is provided with a deep flange n and a nipping lever o formed with
a notch or recess in which the flange n fits loosely, is pivoted to a small rocking
frame p mounted locsely on the spindle i. The pivot of the lever o is in the
horizontal plane of the spindle and at right angles to the spindle that is it is
parallel to the faces of the flange n. The free end of the nipping lever o is

page_text: weighted or is secured to an adjustable spring r and normally rests on an adjustable
stop s secured to the bracket 7. It will readily be seen that as the pivot of the
nipping lever o is raised by rocking the frame p on the spindle i it first grips the
flange n and is then raised completely off its stop thus rotating the pulley h and
separating the carbons to strike the arc. On lowering the pivot of the lever o the
pulley is turned to feed the carbons together until the free end of the lever rests
on the stop s and any further lowering of the pivot gradually releases the grip on
the flange n to allow the carbons to feed together at a continuous and exceedingly
steady rate according to the consumption of the carbons.
Although the adjustable spring ris shown in the drawings yet in most cases it
can be dispensed with the lamp working perfectly without it.
The small rocking frame is connected by the link t to the main rocking
frame v mounted on the saddle bracket / and connected to the cores wa of the
shunt and series solenoids z. y. A dash pot I may be employed to still further
steady the lamp if necessary.
"Mounted longitudinally on the main rocking frame v is a screw 2 on which is fitted
a weight 3. By operating the screw, the weight is traversed along the frame 'to
adjust the lamp.
The operation of the lamp is as follows: On the current passing to the lamp
the core of the series solenoid is drawn down and through the main rocking
frame connecting link and small rocking frame p draws up the pivot of the
uipping lever o and causes the lever o to first grip the flange n of the pulley h and
then rotate it to strike the arc. As the resistance of the arc increases the power
of the series solenoid 2 decreases whilst that of the shunt solenoid y, if one is
employed; increases and the nipping lever is gradually lowered on to its stop s
when the lever releases its hold on the flange n and a continuous and steady
feed is obtained by the flange n slipping slowly through the nipping lever o.
The duplex lamp shown in Figs. 4, 5, 6, and 7 is actuated by one striking and
regulating mechanism there being two sets of travellers a a¹ e e¹ and carbons, two
chains and pulleys h h and two uipping levers o o' actuated by one set of frames po
and solenoids 2. y. The duplicate parts are similar to those described for the
single lamp and are indicated respectively by the same reference letters the second
set being indicated by a dash to the letter.
The nipping levers oo' of the two sets of carbons are arranged so that say o¹ when
the rocking frames v p are actuated leaves its stop s' before the other.
The operation of the duplex lamp is as follows: On the current passing to the
lamp the rocking frames pv raise the nipping levers o o' and the first o' to leave
its stop simply separates the corresponding carbons leaving the first pair of
On the further
carbons that is the pair to be first consumed-still in contact.
motion of the rocking frames the nipping lever o of the first pair of carbons leaves
its stop s separates the points of the carbons and strikes and maintains the arc.
During the time that the first set of carbons are burning the nipping lever o' of the
second set of carbons keeps its grip on their pulley and keeps the points of the
carbons apart. When the holders of the first set of carbons come to rest on
the framework of the side rods and cannot feed further together the rocking frames
gradually lower the nipping levers until the second lever o' comes in contact with
its stop and releases the second pulley of the second set of carbons which then
come in contact and the first set are immediately extinguished. The regulating
frames then again raise the nipping levers and strike the are for the second pair
of carbons which coutinue to burn until completely consumed.
In a similar manner a lamp with three or more pairs of carbons can be operated
by a single striking and regulating mechanism.
In order to prevent the chains g from slipping on their pulleys h the pulleys are
provided with projections fitting in the links of the chains, or preferably cords are!
5 employed in lieu of chains.
+ 1;
A cut out for the lamp consists essentially of two carbon blocks 4, 5 normally

page_text: resting in contact and connected to the terminals of the lamp. The series
solenoid is provided with a keeper 6 and its armature 7 is adapted to slide on the
rods 8 and carries one carbon block 4. The other carbon block 5 is carried by a
small bracket 9 from the disc m.
When the current is passed to the lamp a portion passes through the series
On
solenoid z which attracts its armature 7 and separates the carbon blocks, 4, 5.
the failure of the lamp the armature 7 and block 4 fall aud cut out the lamp from
the circuit the whole current passing through the carbon blocks 4, 5.
In a modification a lamp constructed according to this invention is arranged to
work in a series circuit with a shunt coil only. In this case the weight of the core
of the shunt coil or a spring tends to operate the friction grip device to keep the
carbons apart. The shunt acts against the spring or weight to strike the arc and
maintain the feeding of the carbons together during consumption.
When working a number of such lamps together in series by a series electric
generator in order to excite the series electric generator, a resistance equal to the
working resistance of the circuit is inserted across the terminals of the machine
and when the generator has built up its E.M.F. it is shunted across to the lamps
either by hand or automatically.
Having now particularly described and ascertained the nature of my said inven
tion and in what manner the same is to be performed, I declare that what I
claim is:
1. In an electric arc lamp in which the carbon holders are connected together
by a flexible connection passing over a pulley and in which the carbons tend to
approach, the friction grip device consisting of two parallel nipping surfaces
moving with the pulley, a nipping lever having a notch fitting loosely on the
nipping surfaces and pivoted parallel to the nipping surfaces, a
means for
determining the position of the lever pivot according to the resistance of the arc,
and of a stop on which the notched end of the lever rests substantially as
described.
2. In an electric arc lamp in which the carbon holders are connected together
by a flexible connection passing over a pulley and in which the carbons tend to
approach, the friction grip device consisting of a rocking frame mounted on the
spindle of the loose cord pulley, of a means for determining the position of one end
of the frame according to the resistance of the arc, of a nipping lever having a
notch and pivoted to the frame, two parallel nipping surfaces parallel to the pivot
of the nipping lever and moving with the pulley, and of a stop on which the notched
end of the lever rests, substantially as described.
3. In an electric arc lamp in which the carbon holders are connected together
by a flexible connection passing over a pulley and in which the carbons tend to
approach, the friction grip device consisting of a rocking frame mounted on the
spindle of the loose cord pulley of a solenoid core connected to the rocking frame, of a
corresponding solenoid arranged in series, of a nipping lever having a notch and
pivoted to the frame in such manner that the lever pivot is raised as the solenoid
core is drawn into its coils, two parallel nipping surfaces parallel to the pivot of
the nipping lever and moving with the pulley, and of a stop on which the notched
end of the lever rests, substantially as described.
4. In an electric arc lamp in which each pair of carbon holders are connected
together by a flexible coupection passing over a pulley and in which the carbons
tend to approach, a series of friction grip devices one for each pair of carbons and
each device consisting of two parallel nipping surfaces moving with the corre-
sponding pulley, a nipping lever having a notch fitting loosely on the nipping
surfaces and pivoted parallel to the nipping surfaces, of a stop on which the notched
end of the lever rests, and of a single means for determining the positions of the
lever pivots according to the resistance of the arc the levers being successively
raised off their stops substantially as described.

page_text: 5. The improvements in electric arc lamps substantially as described with
reference to the drawings.
Dated this 15th day of October 1895.
WHEATLEY & MACKENZIE,
40 Chancery Lane, London, W.C., Agents.