IMPROVEMENTS
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by the said James Brockic at the Office
of the Commissioners of Patents on the 19th May 1882.
JAMES BROCKIE of Brixton in the County of Surrey
ELECTRIC ARC LAMPS,"
"IMPROVEMENTS
IN
The first part of this Invention relates to a new construction of electric lamp, in
order to prevent the overfeeding of the carbons, For this purpose I use a
differential solenoid which directly operates the botton carbon holder, the top
holder is preferably racked, and gears into a pinion, which pinion has a large
escapeinent or star wheel upon its axis, a lever carrying an anchor is placed over
this wheel and by its movement permits only one tooth to escape at a time; but I
construct this anchor so that the escape wheel cannot oscillate it, the anchor must
be moved before the escape wheel can turn. Now I gear this escape lever to the
core of the differential solenoid so that when the core arrives at a certain point, a
tooth will be permitted to escape and the carbon therefore be permitted to feed a
well defined amount, this feed will then cause the core to separate the carbons and
another tooth of the wheel to escape, but this second tooth may represent a much
smaller feed than the former. When the current ceases, the detent is taken out of
gear altogether and the carbons can thus meet.
The form of the escape wheel and releasing anchor or detent may be varied
considerably; in practice I prefer a disc having small pins projecting from its
side, which are engaged by two detent pieces worked directly by the core of the
solenoid.
The second part of this Invention relates principally to improvements in the
construction of lamps having two or more pairs of carbons, and to various mechanical
details in lamp construction generally.
The first improvement consists in furnishing each pair of carbons in an electric
amp with a magnet or solenoid, in order to separate the carbons when the lamp is

page_text: first lighted, these magnets or solenoids are in parallel branches of the same circuit,
so that if all the pairs of carbons in the lamp are in contact, the main current will
pass through all the magnets and separate each pair, but if only one pair be in
contact the current will only pass through the coils belonging to that particular
pair, and thus the arc will be established between them. Now I propose that only
one pair of carbons shall be in contact at a time, the others being prevented from
touching by means of a suitable locking device; thus when a current is passed
through the circuit, only one pair of carbons will light, but I arrange when this
pair is consumed that its holder releases the locking gear which keeps the next pair
apart, so that this said next pair will come into contact; when this takes place the
main current will immediately pass round the coils of the second pair, and separate
them, the current being immediately diverted from the first pair, as the current will
pass through the circuit of least resistance.
Another method of constructing double or multiple carbon lamps according to
this Invention, is to separate the carbons by means of a magnet or solenoid, wound
partly by the main circuit and partly by a shunt across the arc. In this case only
one magnet or solenoid need be used, for when a new pair of carbons is permitted
to come into contact, the shunt coil of the arc-striking solenoid will be short
circuited, so that the main coil will exert its full power and separate the carbons.
Instead of using any locking device before spoken of in order to keep the second
or other pairs of carbons apart, the coil regulating the feed of the carbons may be
caused to lift the brakes off the feeding gear in succession.
The feed regulator in the above lamps consists of a simple shunt coil across the
arc or a differential coil or coils may be used.
The next part of this Invention relates to the construction of lamps in which
only one carbon holder is movable, and where wheelwork is employed to retard the
descent or ascent of the movable holder. The method usually employed to effect
this, is to lift (by means of a magnet or coil) the whole of the train of wheels
together with the holder the distance requisite for the arc. Now I propose to lift
only the first wheel of the train along with the holder, and for this purpose I place
the first wheel on a rocking lever whose pivot is at or near the pivot of the second
wheel, which I place level with the first, so that, although the first wheel may be
moved a short distance up or down, its relation or gearing with the second is not
materially altered. This plan of lifting only a portion of the gearing, gets rid of
many mechanical difficulties, as the frame carrying the regulating train is stationary
and may then form the main framing of the lamp, also much less weight need be
lifted and therefore much less counterbalance or strength of magnet is required.
Another method is to move the whole train on a pivot on the same horizontal line
with the pivot of the first wheel, in this case the train and framework itself may
form a convenient balance weight for the rack, Another method is to fix a magnet
at the extremity of the holder, this magnet will travel up and down with it and
receive its current from a flexible conductor; this magnet to lift the carbon holder
the correct distance, the carbon holder rod may in this case conveniently be
made hollow, with a central rod fitting inside and worked by the said travelling
magnet.
The next part relates to lamps having no clockwork or geared wheels to retard
the feed of the carbons. I propose to construct lamps with the top holder falling
by gravity but I cause the holder in its descent to raise a weight less than its own
which weight may conveniently be placed in a tube the weight forming a piston,
this will retard the descent of the holder considerably. I regulate the carbon
holder of such a lamp by means of a differential solenoid which works a pawl
operating upon the periphery of the wheel over which the cord passes, which
suspends the holder and counterpoise, or the holder may be operated upon by
means of a lifting lever applied to the holder itself, which lifting lever presses the
holder against a friction roller and thus lifts it by a jambing or upward movement,
the feed or slip being permitted by the reverse movement of the jambing lever;
the face of this jambing lever may be covered with some elastic substance if

page_text: preferred, or the axis upon which it works may be mounted on a spring which will
thus enable the carbon rod to be pressed against the roller but not absolutely
locked; I propose to apply such a lifting and regulating lever to lamps having the
carbon rods falling either by simple gravity or retarded by a dash pot or counter
weight; I also prefer to construct such lamps having two pairs of carbons operated
upon by the same regulating coil or coils.
In lamps where wheel or rack work is employed I propose to use a central brass
tube fixed into the bottom plate of the lamp and enclosing the rack or carbon
holder, a small slot being made in this said tube to allow the first wheel of the
retarding train to get into gear, this tube will therefore prevent the accumulation
of the products of carbon consumption on the more delicate parts of the gearing;
this accumulation of sulphurous matter being a serious objection to the use of
small wheels in electric lamps, and for which this said tube is a complete remedy;
the tube also forms a convenient centre upon which to arrange the mechanism, thus
getting rid of all framework, and it also forms an excellent suspender for the lamp;
this tube may also be applied to lamps having no clockwork.
Lastly I propose to alter the resistance of the regulating coil of electric lamps
automatically by the descent of the carbon holder, to compensate for the shortening
of the carbons, this plan is particularly necessary where very long carbons are
used; also instead of altering the resistance of the coil alter the tension of the
spring against which the regulating coil acts, this I propose to do by putting a long
inclined plane on the side of the carbon holder rod, and this plane as it descends
presses back a lever which lever alters the spring or leverage operated by the
regulating coil.

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 18th November
1882.
JAMES BROCKIE of Brixton in the County of Surrey
ELECTRIC ARC LAMPS
"
"IMPROVEMENTS IN
My present Invention will be best understood by reference to the accompanying
drawings.
Figure 1 shows a lamp constructed according to the first part of this Invention,
where the carbons are adjusted by a differential solenoid and step by step
escapement
Figure 2 shows a double lamp with the arc striking magnets or solenoids in
parallel circuit and the general details consequent on this method.
Figure 3 shows a double lamp with a differential are striking solenoid.
Figures 4, 5, and 6 show various mechanical devices for obtaining the arc in
lamps where wheel work is employed.
Figure 7 shows a double lamp with counterpoise and double spring pawl.
Figure 8 shows a lamp with an eccentric pawl controlling the carbon holder.
Figure 9 shows a lamp frame with central tube around which the mechanism is
placed.
Figures 10, 11, 12 and 13 show various methods of compensating the decrease
of resistance in the carbons of a lamp.
Figures 14 and 15 are reverse views Figure 14 being a front and Figure 15 a
back elevation of a lamp embodying several features in this Invention.
The first part of this Invention relates to a new construction of electric lamp in
order to prevent the too close approach or feeding of the carbons.
Referring to Figure 1 of accompanying drawings I place a differential solenoid A
in the lamp which directly operates the bottom carbon holder B. The top holder C
is preferably racked, and gears directly or by an intermediate train into a pinion P
which pinion has a large escapement wheel E upon its axis; a lever or rod F
worked by the differential solenoid A carries an anchor K which latter engages the
teeth or pins of the escape wheel E.
It will be seen that when the core of the solenoid A. arrives at a certain point
a tooth or pin will be permitted to escape and the carbon rod C therefore be
allowed to descend a well defined amount, this will then cause the core to draw
down the lower carbon and another tooth of the wheel E to escape, but this second
escapement may represent a much smaller feed than the former by placing the
teeth or pins of the escape wheel at different intervals. When the current ceases
the anchor escapement or detent K is taken out of gear altogether and the top
carbon can thus descend until the carbons meet.
The second part of this Invention relates to improvements in lamps having two
or more pairs of carbons and to various mechanical details applicable to are lamps
generally.
The first improvement consists in furnishing each pair of carbons in a lamp with
a magnet or solenoid in order to separate the carbons when the lamp is first lighted
as shown in Figure 2. I place these solenoids A¹ A² in parallel branches of the
same circuit as shown and I insulate the two negative carbon holders N' and N²
which are respectively in connection with the two are striking solenoids A' and A².
Now I arrange that when the lamp is fully supplied with carbons that only the
pair C¹ are allowed to come into contact, this I do by means of the lever L which
engages or stops the gearing of the pair C² and thus prevents the descent of the

page_text: holder H2. Now it will be seen when the current is passed through the lamp the
circuit will be through the solenoid A' and carbons C' and thus they will be
separated by the action and gearing of the solenoid A' the shunt solenoid or
magnet B then regulates the feed of the top holder H by means of the brake D¹
on the last wheel W of the train belonging to the pair C¹. Now when this pair is
consumed, the stop or striker S on the carbon holder H¹ comes in contact with the
end of the lever L and so tilts it up thus lifting it out of gear with the escape
wheel W belonging to the pair C. Immediately this takes place the carbon
holder H descends until the new carbons C² come into contact. The circuit of
least resistance will thus be through the solenoid coil A² and carbons C and this
pair will thus be separated, and the light will immediately disappear from between
the points of the pair C'. The future regulation of this new pair will still be
controlled by the same shunt coil B as it is common to and controls both brake
levers D¹ and D².
Another method of constructing double or multiple carbon lamps according to
this Invention is shown in Figure 3. In this case both the lower carbon holders
N' and N2 are controlled by a solenoid A wound partly in the main circuit and
partly in a shunt across the arc; this solenoid is for the purpose of separating the
carbons and obtaining the arc when the current is first passed through the lamp.
The regulation or feed of the upper carbons being controlled by the shunt coil B.
Now I arrange as in the previously described double lamp, that only one pair shall
be in contact at a time, the carbon holder H2 being prevented descending by means
of the stop lever L engaging the train of wheels belonging to the holder H. The
action of this lamp is as follows;-when the current is passed through the lamp
the circuit will be through the carbons C' (as the pair C2 are kept apart as before
explained) and the lower holders will be inmediately drawn down by the differential
coil A the correct distance for the arc, the coil B now regulates the descent of the
top carbon holder H' until the striker S comes in contact with the lever L; when
this lever is thus lifted out of gear with the train belonging to the holder H2 this
bolder descends until the new pair of carbons meet; the moment this takes place,
the shunt coil of the solenoid A is practically cut out or short circuited and the
main coil is thus able to pull down the core and negative holder a distance equal
to a correct arc or nearly so; then the future regulation is determined by the shunt
coil B as before until the second pair is exhausted. Instead of using any locking
device L such as described in order to keep the second or other pairs of carbons
apart while the first pair are burning, the regulating coil B may be arranged. to
lift the brakes off the feeding trains in succession.
A differential coil may be used if desired to regulate the feed of the carbon in
such a lamp instead of a simple shunt coil as shown. The rod R is arranged to
lift off the brakes when no current exists in the circuit, and as shown it may also
alter the tension of the regulating spring P according to the pull of the arc striking
solenoid A.
The next part of this Invention relates to the construction of lamps in which
only one carbon holder is movable and where wheel work is employed to retard
the descent of the movable holder. The method usually employed to effect this is
to lift (by means of a magnet or coil) the whole of the train of wheels, together
with the holder, the distance requisite for the arc.
Figures 4, 5 and 6 show various methods of obtaining the are according to this
invention. Referring to Figure 4 I propose to lift only the first wheel W of the
retarding train, this wheel is pivotted on a radius bar R which latter moves on a
pivot coincident with that of the second wheel S. It will be seen that this first
wheel W may be moved up or down a short distance (a quarter inch for example)
without materially affecting its gearing with the rack K especially if the teeth are
made suitable for such a movement. This plan of lifting only a portion of the
train gets rid of some mechanical difficulties, as the frame carrying the regulating
train is stationary and may therefore form the main framing of the lamp also much

page_text: less weight has to be lifted and therefore much less weight of counterbalance or
strength of lifting magnet A is required.
Another plan is shown in Figure 5 in this case I rock the whole train on a
pivot on the same horizontal line with the first wheel W and in Figure 6 on the
same pivot as the first wheel W in horizontal or vertical position so that the train
and its framework may form a convenient counterbalance for the rack K.
two latter methods have the advantage of keeping the gearing between the rack K
and first wheel W nearly constant whatever the position.
The
The next part of my Invention relates to lamps having no clock work or geared
wheels to retard the feel of the carbons
I propose to construct lamps with the top holder falling by gravity, but I cause
this holder by its descent to raise a weight, which weight may conveniently be
placed in a tube, the weight forming a piston which will retard the descent of the
holder considerably. The tube in which the balance weight or piston X Figure 7
moves may be much shorter than the fall of the carbon holder, as the chain or
flexible wire connecting the rod with the weight may pass over reducing pulleys
as shown in Figure 7 I regulate the carbon holder of such lamps by means of a
differential solenoid A which works the spring pawls PP operating upon the
periphery of the wheels W W over which the suspending chains or cords pass, or
which lever is
the holders may be operated upon by lifting lever L as in Figure
applied directly to the carbon holders, pressing them against the friction roller R
the lifting lever may be faced with India rubber or other yielding substance or the
lever may be mounted on spring bearings to prevent the overjambing of the rod
between the pulley or friction roller R and lifting lever L.
The next mechanical improvement according to my Invention is shown in
Figure 9 I propose to use in lamps having wheel work, a central tube T fixed
into the bottom plate B of the lamp which tube encloses the racked carbon
holder H a small slot is cut in this tube to allow the first wheel W of the train to
engage the rack, this tube will prevent the accumulation of the products of carbon
consumption on the more delicate part of the gearing, this accumulation being a
serious objection to the use of geared wheels in electric lamps. The tube also
becomes a convenient centre around and upon which to arrange the parts of the
lamp, thus getting rid of all framework; it also forms an excellent suspender.
Lastly according to my invention I alter automatically the regulating mechanism
to compensate for the decrease in resistance of the carbons as they are consumed in
order to maintain a constant length of arc during the whole time the lamp is
burning even although very long or resisting carbons are used. Figures 10, 11, 12
and 13 show the various methods which I conveniently adopt.
The general principle upon which they all work is the alteration of the tension
spring balance weight or the power or leverage of the regulating coil. Figure 10
shows the automatic alteration of the regulating spring S; for this purpose I put
or cut an inclined plane A on the back of the descending carbon holder C, a lever L
to which the spring S is attached rubs against this plane and it will be seen that
as the rod C descends, the tension of the spring will be gradually reduced and
therefore the solenoid or coil B will have less work to perform. Now as the said
coil B has less current passing through it when. short carbons are in the lamp
than when long, this inclined plane may be made to compensate exactly for the
reduced strength and thus as before stated an arc of a nearly constant length may
be obtained in a lamp even although very long or very resisting carbons are used.
The lever L has an adjustable arm L² which may be shortened or lengthened and
thus the amount of compensation or alteration of the tension spring may be varied
with the same inclined plane. This is necessary as different carbons have a
different resistance and therefore more or less compensation is required.
Figure 11 shows a worm or screw R and travelling nut N altering the spring S
instead of the inclined plane on the holder.
Figure 12 shows the inclined plane altering the position of the balance or
regulating weight Z of the lamp by means of a small chain or cord C.

page_text: Figure 13 shows the inclined plane altering the position of a core C in the
regulating solenoid B and thus altering its power or attractive force on the other
core C which lifts the brake. This inclined plane or the screw I also use to alter
the resistance of the shunt coil and thus compensate for its reduced strength
Figures 14 and 15 show reverse views of a lamp containing several of the
foregoing features videlicit: 1st. The arc is obtained by the rocking of the train on
the centre of the first wheel W 2nd The automatic alteration of the regulating
spring is effected by an inclined plane on the back of the holder H regulating or
altering the lever L to which the spring S is attached and 3rd the central
protecting tube T forming the mainstay of the various parts of the lamps all as
previously described.
And having now fully described the nature of my said invention and in what
manner the same is to be performed I declare that I claim
First The construction of an electric arc lamp having the lower carbon holder
or holders regulated directly by a differential solenoid this solenoid also controlling
the feed or descent of the top holder or holders by working an anchor or detent
which permits an escapement wheel to move a well defined distance at each
oscillation of the said anchor or detent all substantially as described with reference
to Figure 1 of accompanying drawing
Second-In arc lamps baving two pairs of carbons, constructing the same with
a separate magnet to each pair to obtain the arc, which magnets are in parallel
branches of the main circuit of the lamp, in combination with a locking lever which
prevents the second pair coming into contact until the first pair is consumed, the
feed or regulation of such lamp being determined and controlled by a shunt coil or
magnet across the are or by a differential coil, all substantially as described and
shown with reference to Figure 2 of the accompanying drawings.
Third In are lamps having two or more pairs of carbons; constructing the
same with a differential solenoid or magnet which works both or all the negative
or lower holders, in combination with a locking lever or like device which prevents
the contact of the second or succeeding pairs until the first or previous pair is
consumed, the said locking device being operated by the carbon holder of the pair
in action. The differential solenoid being for the purpose of securing the arc
between the second pair of carbons when the latter make contact, all substantially
as described with reference to Figure 3 of the accompanying drawings.
Fourth In arc lamps in which wheel work is used to retard the feed of the
carbons; the separating of the carbons by the lifting of the first wheel of the train
together with the upper or movable carbon holder; the said first wheel being
mounted on a horizontal radius bar or bars rocking on a pivot in line with the
pivot of the second wheel substantially as set forth and with reference to Figure 4
of the accompanying drawings.
Fifth-In order to obtain the are in lamps where wheel work is employed to
retard the feed of the carbons, rocking the whole train of wheels on a convenient
centre, the first wheel of such train gearing into the teeth of the carbon holder and
thus lifting the holder when oscillated; the train of wheels and its frame forming
a lever lifting the holder and thus separating the carbons. The train in such cases
making if desired a suitable balance for the holder in order to reduce the work to
be done by the lifting or are striking solenoid or maguet all substantially as
described and with reference to Figures 5 and 6 of the accompanying drawings.
Sixth The combination of parts forming a double carbon electric lamp where
the descending carbon holders pull up a piston or counterpoise in a cylinder, which
may or may not contain a liquid to hinder the ascent of the said piston, the
regulation of such a lamp being controlled by a differential solenoid operating a
double spring pawl upon the peripheries of the wheels over which the suspending
chain or cord passes all substantially as described and shown with reference to
Figure 7 of the accompanying drawings.
Seventh Regulating lifting or controlling the carbon or carbon holders of an
electric lamp by ineans of an eccentric friction pawl pressing the said carbon or

page_text: holder against a pulley; the face of said friction pawl to be covered with some
elastic substance or the pivot upon which the said pawl moves to be flexible, in
order to prevent the actual locking of the carbon or rod; all substantially as
described and shown at Figure 8 of the accompanying drawings.
Eighth In lamps where wheel work is used; constructing such a lamp with a
central tube firmly secured to the main or base plate within which tube the carbon
or its holder slide, a slot being cut in the side of the tube to allow the first wheel
of the train to engage the carbon or its holder. This tube to form the mainstay of
the lamp in order to dispense with pillars or frames usual in electric lamps of this
class to protect the wheel work from the particles of carbon arising from the lamp
all as described and shown in Figure 9.
Ninth In arc lamps the automatic alteration of the regulating mechanism in
order to compensate for the gradually reduced resistance of the carbons as they
consume substantially by the methods and mechanical contrivances described and
with reference to Figures 10, 11, 12 and 13 of accompanying drawings
Tenth The combination of parts forming an electric arc lamp shown in
Figures 14 and 15 of accompanying drawings where the arc is obtained by the
rocking of the wheel work on the pivot of the first wheel, the said first wheel
gearing into the teeth of the carbon holder. The automatic movable alteration of
the spring against which the shunt coil acts by means of an inclined plane cut on
the back of the said movable holder; and the employment of a central tube around
and upon which the whole mechanism of the lamp is arranged, all substantially as
described with reference to the above drawings.
In witness whereof I the said James Brockie have hereunto set my hand and
seal this
day of November in the year of our Lord One thousand
eight hundred and eighty two.