IMPROVEMENTS IN ELECTRIC LAMPS
Year: 1879

page_text: LETTERS PATENT to James Brockie, of Brixton, in the County of Surrey,
the Invention of "IMPROVEMENTS IN ELECTRIC LAMPS."
PROVISIONAL SPECIFICATION left by the said James Brockie at the Office
of the Commissioners of Patents on the 19th September 1879.
JAMES BROCKIE, of Brixton, in the County of Surrey. "IMPROVEMENTS IN
ELECTRIC LAMPS."
This Invention consists of a method of constructing and regulating electric lamps
whereby the complicated mechanism usual in such apparatus is dispensed with to a
great extent, and less attention is needful in working them, and also in order that
two or more lamps may be put in the same circuit without interfering with the
regulation of each other.
I use periodical regulation of the lamps, and not the variable strength of the
current, as in most lamps hitherto constructed; thus the regulation is rendered
independent of the strength of the current, and therefore two or more lamps may be
put in series, as far as difficulties of regulation are concerned.
.
For the purposes of this Invention a magnet or solenoid is supplied to each lamp,
preferably in a branch of the main circuit, and a commutator cuts out this magnet
momentarily at stated pre-arranged periods, say every minute or two minutes. This
commutator may conveniently be worked by the engine or electro machine producing
the current, or a separate motor or clock train may be used for this purpose. The
effect of this momentary cutting out of the magnet. is to allow the carbons to drop
together, when they are immediately separated the requisite distance for the develop-
ment of the arc; so the lamp is readjusted as often as the magnet is cut out of
circuit. A lamp working on this principle may be conveniently constructed as
follows-Only one carbon or its holder, say the upper, is free to move, and falls by
the action of its own gravity; a clutch, pawl, jambing ring, or equivalent device is
geared with the aforesaid magnet, so that when it is powerless the carbon is free to
fall until the carbons meet or touch, but when the magnet is active the carbon holder
Price dl

page_text: is pulled up a short distance by the action of the pawl, thus the lamp will be relighted
or readjusted.
When two or more lamps are put in circuit I propose to readjust the various
lamps at different times to avoid altering the circuit resistance too much; in this
case the various lamp magnets may be in separate branches of the main circuit. In
some cases an independent current is used to influence the readjusting magnets
instead of putting them in the main circuit, the current being commutated at
intervals; but when a separate current is used a magnet is placed in the main
circuit to cut or interrupt this independent circuit or circuits should the lamps be
extinguished.
When this periodical readjustment is found insufficient a periodical feed may be
given to the lamp in addition to the readjustment, this rate of feed being based upon
the average rate of consumption of the carbons to be used, a second magnet worked
by a commutator being added to the negative carbon holder for this purpose, or the
same carbon holder which readjusts may also be fed by this second magnet, or clock-
work may be used.
Although only one carbon holder has been described as movable, both holders
may be geared together if a fixed focus is desired, the action being the same as
described.
In some cases the lamps may be made double, that is, having two pairs of carbons,
so that when one pair is consumed the other may be put in circuit automatically;
this may be arranged as follows :—
The two upper carbons or their holders are connected to the positive pole, and the
two lower to the negative, but only one pair can be in contact at the same time;
this is accomplished by a stop. When the current passes the pair in contact only
are lighted, and when they are nearly consumed the holder of the burning carbon
releases the said stop, when the fresh pair are instantly brought into contact, and
the arc will immediately be established between them and will disappear from the
old ones, which are now prevented from coming together again by a stop; thus
shunts or switches are dispensed with. Only one magnet is necessary to regulate
both pairs of carbons.

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 19th March
1880.
JAMES BROCKIE, of Brixton, in the County of Surrey.
ELECTRIC LAMPS."
•
" IMPROVEMENTS IN
My Invention refers to a method of constructing and regulating electric lamps
whereby the complicated mechanism usual in such apparatus is to a great extent
dispensed with, less attention is needful in working them, and that two or more
may be put in the same circuit without interfering with the regulation of each
other.
I use periodical regulation of the lamps, and not the variable strength of the
current, as in most lamps hitherto constructed; thus the regulation is rendered
independent of the strength of the current, and therefore two or more lamps may
be put in series, so far as difficulties of regulation are concerned.
According to my Invention a magnet or solenoid is supplied to each lamp, prefer-
ably in a branch of the main circuit, and a commutator cuts out this branch magnet
momentarily at stated pre-arranged periods, say every minute or two minutes, or
other short periods, as may be desired. This commutator may conveniently be
worked by the engine or electro-machine producing the current, or a separate motor
or clock train may be used for this purpose, either in the lamp itself or at a distance
from it,
The effect of this momentary cutting out of the magnet is to allow the carbons
to meet, after which they are immediately separated the requisite distance for the
development of the arc, so that the lamp is re-adjusted as often as the magnet is
momentarily cut out of circuit.
Figure 1 shews the general construction of lamp and commutator embodying the
above principles.
Figure 2 shews in plan a method of placing two or more lamps in circuit, where
each lamp magnet is in a separate shunt or branch circuit.
Figure 3 shews a modification of magnet arrangement.
Figure 4 shews a modified arrangement when two or more lamps are put in circuit,
and only one regulating shunt or circuit is employed.
Figure 5 shews general arrangement of lamps having a periodical feed and
periodical re-adjustment of the arc.
Figures 6 and 7 shew the method of arranging the carbons at an angle to each
other for the purposes of this Invention, and Figure 8 is a sectional elevation of
electric lamp having two pairs of carbons.
Referring to Figure 1, A is the upper or positive carbon holder, which is preferably
supplied with a cross head A¹ sliding between the guide bars G, G, to ensure the
carbons being directly opposite, and to prevent them overlapping or passing each
other; B is a magnet or solenoid, which is placed in the branch circuit F with the
commutator E driven by the engine or other motor, as before stated. This said
magnet operates the sudden grip clutch C or equivalent devices, some of which will
be hereafter described. The duty of this clutch or other device is to pull up the
upper carbon holder A the requisite distance for the development of the arc when
the magnet is active, and when not active the clutch frame falls and the two pins
D, D, release the two clutches C, C, and allow the carbon holder A to descend until
the carbons meet.
The action (see Figure 1) is as follows:-Suppose the carbons are touching each
other, a current is now sent through the circuit, the magnet B in the branch F will:
become active and pull up the clutching arrangement C which carries the upper
carbon holder A a short distance, and the lamp will thus be lighted; after the lapse
of, say, one minute or other short period, as may be arranged, the commutator E.

page_text: momentarily cuts out the branch circuit and magnet B, the clutch C is now free
to fall with the carbon holder, the latter falling until the carbons meet; but as the
magnet is immediately put in circuit again the carbons are instantly separated as
at first, and the lamp is thus readjusted; after a lapse of a like period of, say, one
minute, the commutator E again momentarily cuts out the branch circuit and
magnet and a similar operation takes place, and so on until the carbons are con-
sumed; thus the lamp is regulated periodically by the commutator E and not by
the varying resistance of the circuit or varying strength of current.
For all practical purposes the variation or increase in the size of are during the
period the carbons are locked, say one minute, may be neglected, as by using
carbons of ordinary durability, and readjusting frequently, much less variation in
the size of the arc takes place than in lamps of the "Serrin" type, where every
alteration in the strength of the current has its reflex in the altered size of the arc,
and where a considerable difference in the are often takes place before the regu-
lating gear can work. When required, however, even the small increase in the size
of the are during the intervals of re-adjustment may be prevented or modified by
the addition of a spring, as shewn in Figure 3 at S2 acting against the armature
during the latter part of its stroke; its action is as follows:-When the arc is
readjusted, the current being strong, the magnet will overcome the spring S and
draw the armature close up to it, but as the arc increases the spring will gradually
overcome the magnet and the armature will retire, and thus cause the carbons to
approach slightly, say to the extent of one sixteenth of an inch only, for when the
current gets below its normal strength the spring ceases to act as it comes against
the dead stop T, therefore it cannot permit or cause the carbons to approach further,
as is the case in lamps depending upon current strength acting against a spring for
their regulation or re-adjustment. This spring merely acts during the readjusting
intervals to a very prescribed extent, and does not in any way influence the
periodical feed or readjustment of the are whatever the strength of the current may
be or however much it may vary, as the stop T limits the action of the spring to a
fractional part of the length of the arc.
Such a spring as I have just described may be used with advantage, in order
that when the magnet is momentarily cut out at the re-adjusting periods the
armature may retire instantly, or quicker than if no such spring was employed.
Instead of applying this spring to the upper carbon helder armature, as just
described, the lower carbon holder may be made movable to a small extent, say
one sixteenth part of an inch, and be governed by a small magnet in circuit to that
amount or other fractional part of an arc.
The commutator E is constructed to cut out and re-establish the branch magnet
very quickly, so that the carbons shall only be allowed to touch each other for the
fractional part of a second, and the blink or diminution of the light consequent
upon the actual contact of the carbons will not be observed. I find in practice
that during the fall of the contact piece S, Figure 1, from the pin P to the disc K
(only one inch) the re-adjustment is effected with certainty and no blink is
experienced; it is during this fall that the shunt is interrupted or broken. When
two or more lamps are put in the same circuit I propose to re-adjust the various
lamps at different times to keep the circuit resistance more uniform than if all the
lamps in the circuit re-adjusted simultaneously.
:.
Figure 2 shews by diagram an arrangement of three lamps A1, A2, A³, in a circuit,
where each lamp magnet B1, B2, B3, is in a different branch circuit, and each lamp
re-adjusted at different times by the commutator E. If six lamps were in circuit
the lamp magnets might be grouped in pairs, and two lamps regulated simul-
taneously; however, this may be arranged in many ways, according to expediency
or desire, but only one commutator E, having a suitable number of contact pieces,
need be employed to regulate many lamps...
In some cases, as in Figure 3, the regulating magnet B or solenoid is placed in
the main circuit instead of in a branch or independent circuit, as before described,
and a second magnet N is added to the lamp, which latter magnet is placed in a

page_text: branch circuit with the commutator; the duty of this second magnet N is to short
circuit the main circuit magnet B at the regulating periods. In this case the com-
mutator E puts the second magnet N momentarily in circuit, and thus the maiu
magnet B is short circuited momentarily and therefore re-adjusts the lamp, as before
described. This arrangement will admit of a much more feeble branch magnet being
used, and also less care need be taken as to the relative resistances of the main and
branch circuits, as the only duty devolving upon the branch magnet is to short circuit
the main magnet, which operation may be performed by magnets of very dissimilar
powers or resistances. In cases where more than one lamp is in circuit and they are
readjusted at different times, and only one branch circuit is employed, an arrange-
ment shewn in Figure 4 is used. A small wheel W is added to the said second
magnet N in branch circuit; this wheel is partially rotated by it at each impulse
by the pawl P. The duty of this wheel is to prevent the short circuiting of the main
magnet B except at a definite point or points in its revolution, the said wheel
being insulated suitably for this purpose. Thus by setting the wheels in the
various lamps at different points the lamps will be readjusted at different times,
although the magnets (being in the same circuit) are magnetized simultaneously.
Instead of using a second magnet to short circuit the main magnet B the main
magnet may be wound with two coils, one in the main the other in a branch with
the commutator E; when the branch is put in circuit by the commutator the effect
of the main coil is neutralized and the magnet is practically inoperative, thus the
re-adjustment will take place as if the magnet had been cut out or short circuited..
When alternating currents are used the carbons may be arranged at an angle to
cach other, as in Figures 6 and 7. In Figure 6 both carbons are free to move up
and down and are re-adjusted from time to time by the magnet M and any of the
clutches before explained; this arrangement will secure. a fixed focus. The holders
inay be geared together so that they may rise and fall equally. In Figure 7 only.
one carbon holder is movable, and that in a lateral direction; in this case the focus
will shift as the carbons are consumed.
I also construct lamps having a periodical and well defined feed to the carbons
in addition to a periodical re-adjustment. I prefer in such cases to give one carbon
a step by step forward movement by means of a pawl or equivalent device, say
every half minute, for a period of, say, 5 or 10 minutes or less, and then re-adjust
the arc by means of the other carbon to correct the size of the arc and eliminate
any errors arising out of the regular rate and amount of feed, but if this feed is
based upon the average rate of consumption of the carbon no serious difference in
the size of the arc can take place between the re-adjusting periods. Two magnets
will be employed in such lamps, one to operate a pawl to feed the carbon, the other
to effect the readjustment as before described. The two magnets may be com-
inutated at proper intervals as in the previously described lamps. Instead of
making both carbons or their holders movable the feed and re-adjusting may be
effected by one carbon, say the upper. Figure 5 shews the general arrangement of
such a lamp where the carbon holder A passes through a sleeve S, fitting it somewhat
tightly; the holder is urged forward directly by the pawl P2, say for example every
half minute, and the sleeve is actuated by the clutch C, say for example every 5
or 10 minutes, to correct or re-adjust the are; the said intervals however may be
modified greatly. The magnets B and N may be placed in separate branch circuits
with the commutator E which cuts them out at the proper intervals. In some
cases the lamp magnets are arranged so that the magnet N has the double duty of
feeding the carbons and short circuiting the re-adjusting magnet, as shown, and in
such cases only one branch circuit and commutator will be required to regulate
many lamps.
Various modifications in the construction of such a lamp may be made, and I
therefore do not limit myself to the precise arrangements shewn; for instance,
clockwork may be used to give the feed to the carbons for a definite time and then
the re-adjusting magnet may be cut out or short circuited momentarily by the same
train of wheels.

page_text: An arrangement of pawl and rack is shewn in Figure 8 to control the carbon
holder, the action of which is as follows:-When the magnet is inactive the pawl P
is out of the rack which is cut in the holder A, therefore the holder will be free to
fall until the carbons meet; but when the magnet is active the pawl rides over the
fixed pin shewn, enters the rack, and lifts the holder the requisite distance for the
arc. In Figure 5 a pawl P³ having a similar action is shewn, to urge forward the
holder A a definite short distance as before described. In the same Figure another
form of sudden grip clutch is shewn, controlling the sleeve S; this device consists
of a plate C having an armature F fixed to it at one extremity, and a weight G at
the other; to counterbalance the said armature an opening is made in this plate
just large enough to allow the sleeve S to pass freely through it when in a horizontal
position, but when the plate is at an angle it grips or jambs the sleeve. The action
of this device is as follows:-When the magnet B is inactive the plate lies hori-
zontally on the top of the pillar H, the sleeve and holder are therefore free to fall;
but when the magnet is active the plate is lifted at one end by the action of the
magnet and depressed at the other by the balance weight G, as shown, and so jambs
the sleeve and carries it upward with it. By raising or lowering the top of the
pillar H upon which the clutch rests when the magnet is inactive the stroke of the
clutch may be altered to vary the size of the arc as desired.
I sometimes construct lamps on the said periodically adjusting principle, having
two pairs of carbons, so that when one pair is consumed the other pair may be put
in circuit automatically, and thus a practically continuous light may be obtained.
Figure 8 shews the general view and principle of such a lamp. The two upper
carbons or their holders are connected to the positive pole of the battery or electro
machine, and the two lower to the negative; but only one pair is permitted to be
in contact at the same time. This is accomplished by the swinging stop S, which,
as shewn, prevents the pair A¹ meeting by locking the pawl lever C.
The magnet M which is commutated, as before described, at proper intervals works
the spring pawl P before described or other clutching device, and so the periodical
re-adjustment of the arc is proceeded with; when, however, the pair A³ is nearly
consumed, as shown, the pin B on holder A comes in contact with the swinging
spring or stop at S¹, pressing it down until it slips past the guard T, the swinging
bar S is now impelled forward by the balance weight W, locking the clutch C³ and
unlocking the clutch C¹. This operation which is quite automatic will cause the
arc to be established between the new carbons A¹ and to disappear from the old.at
the next re-adjusting period, because the pair A will be then prevented meeting,
but the pair A will be free to meet. The pair A² may now be replaced and the
balance weight W turned to the opposite side, as shewn by the dotted lines, so that
when the pair A¹ is in turn consumed a similar operation to that just described
takes place, and the light will be thus kept practically continuous.
Having now described the nature of my said Invention and in what manner the
same is to be performed, I declare that although I have spoken of and described
only one carbon holder as movable to effect the re-adjustment of the arc when the
carbons are arranged vertically, I do not limit myself to that particular plan as both
carbon holders may be used to attain that end. Indeed, by modifying the con-
struction of many electric lamps now in use, which depend upon current strength
or variation for their regulation, by taking away the regulating spring (or its
action) giving the upper carbon holders a sudden instead of a gradually falling
movement, and placing their magnets in a branch circuit, I can adapt them to this
new method of periodical regulation by means of an automatic commutator without
departing from the essential features or spirit of this Invention. And although I
have described and shown several clutching devices to actuate the carbon holders
of my lamps I do not limit myself to the use of such for this purpose, as numerous
arrangements may be employed; nor do I claim as novel any of the clutches shown
when used to regulate lamps by current strength (although they may be new) but
I have shewn them as various devices suitable in the carrying out of this Invention,
but I claim,-

page_text: First. In electric lamps, re-adjusting the arc at pre-arranged periods or intervals
by means of an automatic commutator, said periodical re-adjustment being inde-
pendent of the varying strength of the current, substantially as set forth.
Second. In electric lamps, giving a periodical and well defined feed to the carbons
in addition to and in combination with a periodical re-adjustment of the arc, in
order to eliminate and provide against serious errors or differences in the size of the
arc consequent upon the said regular feed; the said feed and re-adjustment being
accomplished automatically by a commutator substantially as described, and not
dependent upon the variation of the current or resistance.
Third. In combination with a commutator which momentarily cuts out short
circuits or reverses the lamp magnet at regular intervals, the construction of electric
lamps, substantially as described and shewn with reference to Figure 1 of the accom-
panying Drawings, in order to effect periodical re-adjustment of the arc independent
of the varying current or resistance, as described.
Fourth. In electric lamps re-adjusting periodically, in accordance with this Inven-
tion, the arrangement of two magnets and rotating wheel, substantially as described
and shewn in Figure 4, whereby the main or re-adjusting magnet is short circuited
after a certain number of impulses of the second magnet in the branch circuit with
the commutator, in order that two or more lamps in the same circuit-may be
re-adjusted at different times by one commutator and one branch circuit, substan- .
tially as described.
Fifth. The construction of electric lamps regulating on the said periodical principle,
having the carbons arranged at an angle to each other, substantially as shown in
Figs. 6 and 7.
Sixth. In electric lamps regulating periodically, in accordance with this Invention
as hereinbefore described, the employment of two pairs of carbons in combination
with a stopping device applied to the holders, whereby only one pair can be in
contact at the same time, and also that when one pair is consumed the other pair
may be brought into action automatically, substantially as described and shown
with reference to Figure 8 of the accompanying Drawings.
Seventh. For the purpose of giving a periodical and well defined feed to the
carbons for a definite period, and then re-adjusting the arc to eliminate any error in
the size of the arc arising out of the said regular feed, the construction of electric
lamps, substantially as described with reference to Figure 5.
In witness whereof, I, the said James Brockie, have hereunto set my hand and
seal, this Seventeenth day of March, in the year of our Lord One thousand
eight hundred and eighty.
JAMES BROCKIE. (L.S.)