IMPROVEMENTS IN ELECTRIC ARC LAMPS
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by the said James Brockie at the Office
of the Commissioners of Patents on the 24th February 1882.
JAMES BROCKIE of 6 Saltoun Road Brixton in the County of Surrey
"IMPROVEMENTS IN ELECTRIC ARC LAMPS,"
This Invention has reference to various modifications in the construction of arc
lamps forming part of the subject matter of Letters Patent granted to me dated
19th September 1879. According to the principles and construction of Arc lamps
as described therein. I proposed to give a periodical step by step feed to one of
the carbon holders in the lamp, by means of a commutator driven by the engine,
electric machine or other convenient motor, this rate of feed being based upon the
average rate of consumption of the carbons employed, but in order to eliminate or
provide against errors in the size of the arc consequent upon the said uniform and
arbitrary feed I also proposed to re-adjust the arc at intervals, that is, after a stated
number of impulses had been given to the feeding carbon holder. The first part of
this Invention has reference to some mechanical details in the carrying out of the
aforesaid principle which render the action of the lamps so constructed more certain
and satisfactory. The second part refers to some modifications in the principle of
such step by step or independent feed lamps.
The mechanical details forming the subject of the first part of this Invention
are substantially as follows:-I prefer to give the lower carbon holder the step by
step feed and to readjust the arc by means of the upper carbon holder, although
this method may be reversed, but for the better understanding of the following
description of the various plans under this Invention, it will be taken as granted
that the lower or negative holder is the one urged forward by the step by step
movement, and the re-adjustment of the arc effected by the upper or positive
holder. In the Invention before cited I proposed to accomplish the re-adjustinent
of the arc, after a certain number of impulses of the feeding magnet, by short
TDmine 31

page_text: circuiting the main or arc-striking magnet; now I find in practice it is much
better to reverse its polarity, this is done according to this Invention by winding
the main magnet differentially by a shunt coil across the arc, but the said shunt
coil which reverses it, is only put momentarily in circuit at the readjusting
periods, I also propose in addition to this momentary reversal of the polarity of
the main magnet that another magnet wound in preferably the same shunt as the
reversing coil, be placed in opposition to the said main magnet, in order to pull
the armature smartly away from the poles of the main magnet, as the residual
magnetism or the over or under reversal of its polarity might prevent the armature
retiring with that suddenness which is so essential to the proper performance of
the lamp.
A mechanical sudden contact arrangement suitable for the said
momentary periodical reversals of the main magnet is substantially as follows viz,
the magnet which gives the step by step movement to the lower holder also turns
a ratchet wheel substantially as described in my previous patent referred to, but I
furnish this wheel with a projecting insulated boss upon which a spring or lever
rests; an insulated pin is placed near the outside of the said wheel, so that as the
wheel revolves, the pin will lift the lever or spring off the boss, and at a certain
part of each revolution, allow the spring to drop suddenly upon the boss again;
now I place a contact pin on the said rotating wheel occupying a position between
the said insulated pin and the boss so that as the lever or spring falls from the
insulated pin to the insulated boss, it will rub or touch the said metal or contact
pin momentarily; now this momentary contact completes the reversing coil and
opposing magnet circuit, as before described and thus the arc will be re-adjusted to
its correct length.
It will be seen that according to the foregoing method, the feed and regulation
of the lamps does not depend upon the variation in the length of the arc or the
particular requirement of any lamp in a circuit, but the regulation is purely
mechanical and arbitrary, although of course the rate of feed and the intervals of
readjustment are based upon the well ascertained rate of consumption, and character
of the carbons employed.
The modifications of the before described step by step feed lamps, forming the
second part of this Invention are substantially as follows, the object of them all
being to dispense with the arbitrary readjustment of the arc after a definite
number of impulses of the feeding holder, and in its stead, to cause each lamp in a
circuit to adjust its own are from time to time according to its individual
requirements even although the step by step feed should continue a constant
quantity.
1st Modification. The lower carbon holder to be urged or be permitted to
ascend step by step, by the action of a commutator as previously narrated, in
combination with the upper carbon holder worked by a solenoid or magnet, which
solenoid may be wound differentially by a coil bridging the arc and whose duty is,
first, to strike the arc by lifting up the top holder and then to re-adjust the arc
from time to time; reducing the length of the are should the periodical feed be too
slow, or increasing it should it be too fast, the range or stroke of the said solenoid
core being made sufficient to accomplish this, even although much over-feeding or
the reverse should take place during any run of the lamp.
2nd Modification. The lower carbon holder to have the periodical step by step
feed and the upper carbon holder to be controlled by a solenoid whose duty is,
first, to strike the arc, second to directly alter its size from time to time according
to requirements, and third, to alter the stroke of the armature actuating the
feeding pawl (by say introducing a distance block or blocks between the said
armature and its magnet) if the feeding should happen to be either too fast or too
slow, thus less range of solenoid core will be necessary in this case than in the
former, as the solenoid will really determine the effective stroke of the feeding
magnet and pawl (and therefore the rate of feed) even although the feeding impulses
are given at a uniform rate or number per minute
3rd Modification. One carbon holder to have the step by stop feed, the other

page_text: holder to be controlled by a solenoid whose triple duty is, first, to strike the arc,
second, to alter it directly according to the resistance of the arc, and third, when
over-feeding takes place to divert the current from the feeding magnet
4th Modification. The lower holder to have a step by step feed and the upper
holder controlled by a solenoid, this solenoid works the holder by means of sudden
grip clutch or locking ring, the holder is quite free to fall by its own gravity when
released by the clutch, and has preferably no dash pot to hinder its sudden fall
when released; the action of the combination is as follows:-First, the arc is
struck by the said solenoid lifting the upper bolder a short distance, now as the
regular feed proceeds, the solenoid will adjust the arc according to its resistance,
however as I arrange in this construction of lamp to slightly underfeed the lower
holder, the solenoid will gradually descend, this descent will continue till the clutch
comes against a stop or table, which will then cause the said clutch to relax its grip
on the holder, so the latter will immediately slip quickly through the clutch, and the
carbons will meet, but this has the immediate effect of strengthening the solenoid,
so the are will be re-struck as at first, thus the arcs in such lamps will be re-adjusted
suddenly from time to time
Instead of using a separate shunt or regulating wire and a commutator worked
by the engine or other motor to give the feed to one carbon holder, a clock train or
other regular motor may be placed in cach lamp, the action of which motor to be
controlled, or its effects modified, by the solenoids, by any of the methods before
explained as controlling or modifying the arbitrary step by step movement.
Instead of making the said adjusting solenoids also directly influence tho rate of
feed by means of limiting the stroke of the pawl or otherwise, I sometimes add a
third magnet which is in a shunt across the arc to do this, but the adjusting
solenoid plays an important part in this action of the said third shunt magnet viz:
it tightens or slackens the spring against which it acts, according to the strength
of the current; this combination of a solenoid wound differentially which directly
regulates the size of the are and which in addition alters the tension or leverage of
a spring against which another shunt magnet acts regulating the feed; being
applicable to the regulation of electric lamps of nearly every construction.
The effect of this third shunt magnet or coil when applied either to step by step
lamps in the manner above described, or in lamps which have no step by step feed
but which act by gravity, may be controlled by the solenoid wound in the main
circuit, other than by altering the tension spring or its leverage, by causing the
said main solenoid to alter the actual position of the said third shunt coil or
magnet in relation to its armature, viz, when a strong current exists, the main
solenoid will carry the shunt coil or magnet a little further away from its armature,
and when a weak current exists, it will place it nearer. This latter plan avoids
the use of a spring altogether, as the armature or core against which this final
shunt magnet or coil acts, may have a constant weight pulling it away from the
magnet, the influence of the said magnet or coil depending then upon the distance
between the magnet and armature.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said James Brockie in the Great Seal Patent Office on the 24th August
1882.
JAMES BROCKIE of 6 Saltoun Road Brixton in the County of Surrey
"IMPROVEMENTS IN ELECTRIC ARC LAMPS "
This Invention has reference to various modifications in the construction of arc
lamps forming part of the subject matter of Letters Patent granted to me dated
19th September 1879 No. 3771. According to the principles and construction of
Arc lamps as described therein I proposed to give a periodical step by step feed to
one of the carbon holders in the lamp by means of a commutator driven by the
engine, electro machine or other convenient motor, this rate of feed being based
upon the average rate of consumption of the carbons employed, but, in order to
eliminate or provide against errors in the size of the are consequent upon the said
uniform and arbitrary feed, I also proposed to re-adjust the arc at intervals, that
is, after a stated number of impulses had been given to the feeding carbon
holder.
The first part of this Invention has reference to some mechanical details in the
carrying out of the aforesaid principle which render the action of the lamps so
constructed, more certain and satisfactory. The second part refers to some modifi-
cations in the principle of such step by step or independent feed lamps.
Figure 1 of the accompanying drawings is an elevation constructed according to
the first part of my Invention and Figures 2 and 3 are elevations of lamps con-
structed according to the second part.
The mechanical details forming the subject of the first part of this Invention
are substantially as follows:-I prefer to give the lower carbon holder the step by
step feed and to re-adjust the arc by means of the upper carbon holder as in
Figure 1 although this method may be reversed but for the better understanding of
the following description of the various plans under this Invention, it will be taken
as granted that the lower or negative holder is the one urged forward by the step
by step movement; and that the re-adjustment of the arc is effected by the upper
or positive holder In the Invention before cited I proposed to accomplish the re-
adjustment of the arc, after a certain number of impulses of the feeding magnet,
by short circuiting the main or are striking magnet; now I find in practice
it is much better to reverse its polarity; this is done according to this
Invention by winding the main magnet M. differentially by a shunt coil S across
the arc, but the said shunt coil S, which reverses it, is only put momentarily
in circuit at the readjusting periods; I also proposed in addition to this momentary
reversal of the polarity of the main magnet, that another magnet wound in
preferably the same shunt as the reversing coil be sometimes placed in oppo-
sition to the said main magnet M at x though not shown in the drawing in order
to pull the armature A smartly away from the poles of the main magnet, as the
residual magnetism or the over or under reversal of its polarity might provent the
armature retiring with that suddenness which is so essential to the proper per-
formance of the lamp. A mechanical sudden contact arrangement suitable for the
said momentary periodical reversals of the main magnet is substantially as follows
and is shown in Figure 1 viz the magnet F which gives the step by step movement
to the lower carbon holder also turns a ratchet wheel W substantially as described
in my previous patent referred to but I furnish this wheel W with a projecting
insulated boss B upon which a spring or lever L rests an insulated pin P is placed
near the outside of the said wheel so that as the wheel revolves, the pin P will lift
the lever or spring L off the boss B and at a certain part of each revolution allow

page_text: the spring to drop suddenly upon the boss B again; now I place a contact spring
or pin K on the said rotating wheel W occupying a position between the said
insulated pin P and the boss B so that as the lever or spring falls from the insulated
pin to the insulated boss it will rub or touch the said metal or contact spring or
pin K momentarily; now this momentary contact completes the reversing coil S
(and the opposing magnet if any) as before described, and thus the arc will be
re-adjusted to its correct length as the clutch Z will allow the carbons to meet and
then lift the top carbon the correct distance. It will be seen that according to the
foregoing method, the feed and regulation of the lamps does not depend upon the
variations in the length of the arc or the particular requirement of any lamp in a
circuit, but the regulation is purely mechanical and arbitrary although of course
the rate of feed and the intervals of re-adjustment aro based upon the woll
ascertained rate of consumption and character of the carbons employed.
The modifications of the beforo described step by step feed lamps forming the
second part of this Invention, are substantially as follows; the object of them all
being to dispense with the arbitrary readjustment of the arc after a definite
number of impulses of the feeding holder, and in its stead to cause each lamp in
a circuit to adjust its own are from time to time according to its individual
requirements even although the step by step feed should continue a constant
quantity.
First modification, as shown in Figure 2. The lower carbon holder A is to be
urged or permitted to ascend step by step by the impulses of the feed magnet F
actuated by a commutator as previously narrated in combination with the upper
carbon holder C worked by a solenoid or magnet M which solenoid is wound dif-
ferentially by a coil bridging the arc, and whose duty is first to strike the arc by
lifting up the top holder and then to realjust the arc from time to time, reducing
the length of the arc should the periodical feed be too slow, the range or stroke of
the said solenoid core being made sufficient to accomplish this even although much
overfeeding or the reverse should take place during any run of the lamp.
Second Modification. The lower carbon holder A. Figuro 2 to have the periodical step
by step feed and the upper holder C to be controlled by the solenoid M whose duty
is, first to strike the arc, second to directly alter its size from time to time according
to requirements, and third to alter the stroke of the armature actuating the feeding
pawl D (by say introducing a distance block or blocks between the said armature
and its magnet) if the fooding should happen to be either too fast or too slow;
thus less range of solenoid core will be necessary in this case than in the former,
as the solenoid will really determine the effective stroke of the feeding magnet and
pawl and therefore the rate of feed, even although the feeding impulses are given
at a uniform rate or number per minute.
Third modification also with reference to Figure 2 One carbon holder to have
the step by step feed, the other holder to be controlled by a solenoid M whose triple
duty is first to strike the arc second to alter it directly according to the resistance
of the arc, and third when overfeeding takes place to divert the current from the
feeding magnet, or as shown to complete a shunt circuit R around the feeding
magnet F which circuit will make the magnetism of this magnet permanent, .80
that the feeding armature T will be permanently attracted and therefore, although:
pulsations or intermittent currents are sent by the commutator round the magnet F,
they will not produce movement in the armature T, and therefore the feed will be
arrested until the solenoid M breaks this circuit R by means of the contacts E E or
equivalent means, and then the intermittent currents will have the full effect in.
producing oscillations of the feeding armature T.
Fourth Modification shown in Figure 3. The lower holder A to have a step by step
feed and the upper holder controlled by a solenoid M, wound differentially; this
solenoid works the holder, by means of sudden grip clutch Z or locking device the
upper holder C is quite free to fall by its own gravity when released by the
clutch Z and has no dash pot to hinder its sudden fall when released the action of,
the combination is as follows:-first the arc is struck by the said solenoid M

page_text: lifting the upper holder a short distance; now as the regular feed proceeds, the
solenoid will adjust the arc according to its resistance; however as I arrange in
this construction of lamp to slightly underfeed the lower holder, the solenoid will
gradually descend this descent will continue till the clutch comes against a stop or
table which will then cause the said clutch to release its grip on the holder C; the
latter will thus immediately slip quickly through the clutch, and the carbons will
meet, but this has the immediate effect of strengthening the solenoid and the are
will thus be re-struck as at first, thus the arcs in such lamps will be re-adjusted
suddenly from time to time.
Instead of using a separate shunt or regulating wire and a commutator worked
by the engine or other motor to give the feed to one carbon holder; a clock train
or other regular motor may be placed in each lamp, the action of which motor is to
be controlled or its effects modified by the solenoid by any of the methods before
explained as controlling or modifying the arbitrary step by step movement.
Instead of making the said adjusting solenoids also directly influence the rate
of feed; by means of limiting the stroke of the pawl or otherwise I sometimes add
a third magnet which is in a shunt across the arc to do this; but the adjusting
solenoid plays an important part in the action of the said third shunt magnet viz.
it tightens or slackens the spring against which it acts according to the strength of
the current; this combination of a solenoid wound differentially; which directly
regulates the size of the arc and which in addition alters the tension or leverage of
a spring against which another shunt magnet regulating the feed acts is applicable
to the regulation of electric lamps of nearly every construction as particularly
described in the specification of my Patent No. 1942, dated fourth May 1881.
The effect of this third shunt magnet or coil, when applied either to step by step
lamps in the manner above described, or in lamps which have no step by step feed
but which act by gravity, may be controlled by the solenoid wound in the main
circuit, other than by altering the tension spring or its leverage, viz. by causing
the said main solenoid to alter the actual position of the said third shunt coil or
magnet in relation to its armature thus when a strong current exists, the main
solenoid will carry the shunt coil or magnet a little further away from its armature,
and when a weak current exists it will place it nearer. This latter plan avoids
the use of a spring altogether, as the armature or core against which this final
shunt magnet or coil acts, may have a constant weight pulling it away from the
magnet, the influence of the said magnet or coil depending then upon the distance
between the magnet and armature.
I declare that I claim-
First. In electric lamps which have a periodic arbitrary feed of the carbons in
combination with a re-adjustment of the arc at stated intervals or after a certain
number of feeding impulses; the particular method of reversing the polarity of
the re-adjusting magnet of such lamps by means of the instantaneous contact
arrangement shown in Figure 1 the parts being the revolving wheel W, the
insulated boss B, insulated lifting pin P, the contact lever L and spring K all
working substantially in the manner and for the purposes described.
Second. The construction of electric lamps, in which a definite and gradual feed
is given to one of the carbons and in which the other carbon is regulated by means
of a differential solenoid or magnet acting directly upon it, the stroke of said
solenoid or magnet being sufficient to cover the errors of overfeeding or under-
feeding the arbitrarily feed holder substantially as described with reference to
Figure 2.
Third. The arrangement or construction of electric lamp above secondly claimed
in combination with the special arrangement whereby an additional duty is put
upon the regulating solenoid viz. that the regulating solenoid diverts the current
from the feeding magnet when the are becomes too short; or neutralizes its effect,
by completing a circuit around or in opposition to the said feeding magnet; or puts
a distance block between the feeding armature and magnet; or lifts the feeding

page_text: pawl out of the teeth of the feeding ratchet wheel substantially as described and
shown with reference to Figure 2.
Fourth In electric lamps giving one carbon holder an arbitrary feed and
controlling the other by a differential solenoid or magnet by means of a sudden
grip clutching device in order that when the are becomes too long (owing to the
feed being too slow or otherwise) the solenoid shall allow the clutch to release its
grip and thus the holder be permitted to approach the other, and should this
approach be too much the solenoid shall lift the clutch and holder the correct
distance all substantially as described and with reference to Figure 3.
In witness whereof I the said James Brockie have hereunto set my hand
and seal this Twenythird day of August in the year of our Lord One
thousand eight hundred and eighty two.
JAMES BROCKIE.
(L.S.)