IMPROVEMENTS IN ELECTRIC LAMPS
Year: 1883

page_text: LETTERS PATENT to James Grieve Lorrain of 2 Victoria Mansions in the
City of Westminster Consulting Engineer for an Invention of "IMPROVEMENTS
IN ELECTRIC LAMPS
"
PROVISIONAL SPECIFICATION left by the said James Grieve Lorrain at
the Office of the Commissioners of Patents on the 6th February 1883..
JAMES GRIEVE LORRAIN of 2 Victoria Mansions in the City of Westminster
Consulting Engineer "IMPROVEMENTS IN ELECTRIC LAMPS
"
My present Invention relates to electric arc lamps of the type in respect of which
I obtained Letters Patent, dated the 27th July 1882 N° 3575.
In the specification to my said former Letters Patent I described the employ-
ment in regulating the feed of the carbon or carbons, or electrodes separating the
carbons or electrodes and striking the arc, of a pivotted or swinging solenoid or
sucking magnet arranged as a shunt or derived circuit between the terminals of the
lamp and having its movable core acting directly on one of the carbons or
electrodes against the action of mechanical force. The pivotted or swinging
solenoid or sucking magnet was provided with a piece of soft iron in connection
with which was arranged a fixed and adjustable armature, the whole forming a
combined solenoid or sucking magnet and electro-magnet, the core of which acted
upon by mechanical force, normally supported one of the carbons, or electrodes, but
on the passage of sufficient current around such core released the carbon or
electrode, whilst the pivotted or swinging magnet itself under the magnetic
attraction induced by the passage of such current was caused to move towards its
fixed armature and by mechanical force was returned to its normal position thus
separating the carbons or electrodes. In the said former specification was further
described the employment of a stationary combined solenoid or sucking magnet
and electro-magnet controlling by its core the feed of one of the carbons, or
electrodes, and by a pivotted armature separating the carbons or electrodes and
striking the arc.

page_text: According to one mode of carrying out my present Invention in lieu of arranging
the combined solenoid or sucking magnet and electro-magnet as a shunt between the
terminals of the lamp, I place it in the main circuit, and I invert or change the
position of the parts of the combined solenoid or sucking magnet and electro
magnet and its connections so that one of the carbons or electrodes shall be
supported under the action of the electric current and released by mechanical force,
and also so that the carbon or electrode separating mechanism shall be brought into
a position for operation by mechanical force and shall separate the carbons or
electrodes under the action of the electric current. Or I may wind the combined
solenoid or sucking magnet and electro-magnet with two sets of coils or helices one
of which is in the main circuit whilst the other is arranged as a shunt between the
terminals of the lamp, the relative arrangement of the parts being modified as will
be well understood.
I apply these improvements to the several modifications of lamps described in
my said former specification including the modification in which a fixed combined
solenoid or sucking magnet, and electro-magnet is used as well as those in which
a movable one is employed.
In lieu of using a combined solenoid or sucking magnet and electro-magnet for
the purposes before mentioned I may employ a double or compound electro-
magnet having two armatures one of which controls the feed of the carbons or
electrodes after the manner of the core in the arrangements previously described
whilst the other armature is employed in controlling the carbon-separating
mechanism. The feed controlling armature may be pivotted or otherwise attached
to the magnet when a movable (that is to say a pivotted or swinging) magnet is
used, the armature secondly mentioned being stationary and adjustable, but when
the latter is movable and the magnet fixed, the armature first mentioned is or
may be connected to the other armature the two forming in fact a compound
armature.
I may place the magnet either in a shunt between the terminals of the lamp,
or in the main circuit, or partly in a shunt and partly in the main circuit.
The armature whether fixed or movable which controls the carbon-separating
mechanism may be duplicated if desired and arranged at opposite ends of the
magnet.
These armatures, as also the movable core (when employed) may also be made
the poles of electro-magnets, the wire convulutions of which are in the same circuit
as those on the principal magnet whereby the magnetic action is reinforced or
increased.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said James Grieve Lorrain in the Great Seal Patent Office on
the 3rd August 1883.
JAMES GRIEVE LORRAIN of 2 Victoria Mansions in the City of Westminster,
Consulting Engineer "IMPROVEMENTS IN ELECTRIC LAMPS
"
My present Invention relates to electric are lamps of the type in respect of which
I obtained Letters Patent dated the 27th day of July 1882, No 3575.
In the specification to my said former Letters Patent I described the employment
in regulating the feed of the carbon or carbons or electrodes, separating the carbons
or electrodes and striking the arc, of a pivotted or swinging solenoid or sucking
magnet, arranged as a shunt or derived circuit between the terminals of the lamp,
and having its movable core acting directly on one of the carbons or electrodes
against the action of mechanical force. The pivotted or swinging solenoid or
sucking magnet was provided with a piece of soft iron, in connection with which
was arranged a fixed and adjustable armature, the whole forming a combined
solenoid or sucking magnet and electro-magnet, the core of which, acted upon by
mechanical force, normally supported one of the carbons or electrodes, but on the
passage of sufficient current around such core released the carbon or electrode,
whilst the pivotted or swinging magnet itself, under the magnetic attraction
induced by the passage of such current, was caused to move towards its fixed
armature, and by mechanical force was returned to its normal position, thus
separating the carbons or electrodes. In the said former specification was further
described the employment of a stationary combined solenoid or sucking magnet and
electro magnet controlling by its core the feed of one of the carbons or electrodes,
and by a pivotted armature separating the carbons or electrodes and striking
the arc
According to one mode of carrying out my present invention, in lieu of arranging
the combined solenoid or sucking magnet and electro-magnet as a shunt between
the terminals of the lamp, I place it in the main circuit and I invert or change the
position of the parts of the combined solenoid or sucking and electro-magnet and
its connections so that one of the carbons or electrodes shall be supported under
the action of the electric current and released by mechanical force, and also so that
the carbon or electrode-separating mechanism shall be brought into a position for
operation by mechanical force, and shall separate the carbons or electrodes under
the action of the electric current.
A form of lamp embodying these features is shown in figures 1 and 2 of the
accompanying drawing in which
Figure 1 is a side elevation and
Figure 2 an end elevation, partly in section on the line xx figure 1.
A represents the solenoid or sucking magnet supported in a circular frame B of
brass or other suitable metal by means of pivots or screws C C¹ so as to be capable
of moving in a vertical plane. This solenoid or sucking magnet is arranged in the
main circuit of the lamp in a manner readily understood. Through the hollow
centre of the said solenoid or sucking magnet I place a rod or tube a the said rod
or tube being in fact the core formed partly of soft iron and partly of brass or
other non-magnetic material. That end of the said core nearest the carbon carries
a projection b or gripping device provided with one or more points, or with a knife
edge or edges, either flat or curved or of other suitable form, for supporting the
upper carbon D. In the drawing the projection b partially embraces and supports
the said upper carbon. I also provide a mass c of soft iron at this end of the

page_text: solenoid or sucking magnet, secured to the body of the latter in any convenient
manner, and above the said mass c of soft iron I place a second mass d of soft iron,
which may be adjusted nearer to or further from the mass c by means of a screw d¹
fitted in a socket in the mass d, and capable of turning therein and screwing
through the upper plate or bar e as is well understood, or by any other convenient
means; the parts A. c, d, forming in fact together a combined solenoid or sucking
magnet and electro-magnet. The circular frame B is provided at its bottom with
another plate or bar e (as well as with the one above mentioned at its upper
portion) the said plates or bars supporting the guiding and contact rollers f. f',f,f".
Each pair of rollers may be connected by springs, as shown, which connect their
axles; one of the axles of each pair working in horizontal slots formed in the bars
or plates e as shown, The rollers are thus caused to bear with more or less pressure
upon the carbon passing between them, thereby adapting them for varying sizes of
carbons within certain limits. The outer rollers f, f, serve to react against the
pressure exerted by the core of the solenoid or sucking magnet against the upper
carbon. Screws g, g' are employed for limiting the movement of the solenoid or
sucking magnet A and thus the length of are between the carbons as hereinafter
described. E, E' are the terminals of the lamp insulated from the frame B, as
shown. One of these terminals namely E' is connected by means of a conductor h
with the lower carbon carrier F, which supports the fixed lower carbon G. The
said lower carbon carrier is insulated from the other portions of the lamp as shown
at H. The solenoid or sucking magnet A may be provided on its exterior surface
with an iron or other metal envelope having on its outer surface two recesses in
which the points of the pivots or screws C Center for the purpose of supporting
the said solenoid or sucking magnet. Through the tube of brass or other non-
magnetic material on which the wire forming the solenoid or sucking magnet is
wound, passes the rod tube or core a as above stated. One part of this core is
formed of soft iron, whilst its other part m is formed of brass or other non-magnetic
material. At the outer end of this part m of the core is adjustably fixed the
projection or knife edge b for supporting the upper carbon as hereinbefore stated.
I prefer to insulate this projection or knife edge as shown for the purpose of
preventing sparking at this point. To the outer end of the part 1 of the core I
may attach a bar or disc l' of soft iron to increase the action of the solenoid or
sucking magnet upon the iron portion of the core, and also to limit its inward
motion. At the back end of the solenoid or sucking magnet is secured a frame n
carrying a movable screw threaded pin o on which works the nut p. To one end
of this pin o is attached one end of the spring q, whilst its other end is attached to
the part or ' of the core a.
l
The tendency of this spring is to withdraw the core a
from out the solenoid or sucking magnet and away from the upper carbon with a
force which may be regulated by the nut p, whilst the action of a current traversing
the solenoid or sucking magnet is to suck in the core a and force its outer end into
contact with the upper carbon. An adjustable piece on the outer portion of the
part m of the core prevents the spring q draw out the latter too far when no
current traverses the solenoid or sucking magnet. The latter is provided with an
adjustable spring 8 carried by a bracket or frame g¹ and arranged for keeping the
same in a horizontal or nearly horizontal position when a current traverses it, but
inclines its front end downwards when it is not traversed by a current.
suspending rod K at its top is bent at right angles and provided with an adjustable
suspending ring K³, as shown, so that the lamp may be hung in a vertical
position.
The
The lamp operates in the following manner, namely:-The carbons being together
in the first instance, and the current switched on, it passes in its course through
the solenoid or sucking magnet, which is in an inclined position at commencement,
drawing inward the soft iron part of the core against the action of the spring q,
and forcing outward the part m and projection or knife edge b into contact with
the upper carbon. At the same time the mass c is magnetised and tends to attract
the mass d but since the latter is fixed the solenoid or sucking magnet is attracted

page_text: towards it and so turns or swings on its pivoted axis through a small arc, against
the action of the spring s into a horizontal or nearly horizontal position, and into
contact with the screw bolt g, lifting the upper carbon a short distance, and
striking the arc, the length of which is determined by the suitable adjustment of
the mass d and screwed bolts g, g'. As the carbons gradually burn away the
resistance of the arc increases when less current necessarily passes through the
lamp and solenoid or sucking magnet circuit, drawing in the core with less force
and allowing the spring g to slightly withdraw the pressure of the core and its
projection or knife-edge from the upper carbon and allowing it to descend a little.
This continued and rapidly recurring action of the solenoid or sucking magnet
causes the lamp to burn steadily whilst in use.
I apply the above described improvements to the several modifications of lamps
described in my said former specification, including the modification in which a
fixed combined solenoid or sucking magnet and electro magnet is used, as well as
those in which a movable one is employed; the relative arrangements of the various
parts being modified as will be readily understood.
In lieu of using a combined solenoid or sucking magnet and electro-magnet for
the purposes before-mentioned I may employ a double or compound electro-
magnet, having two armatures, one of which controls the feed of the carbons or
electrodes after the manner of the core in the arrangements previously described in
the specification to my said former Letters Patent, whilst the other is employed in
controlling the carbon separating mechanism. The feed controlling armature may
be pivotted or otherwise attached to the solenoid or sucking magnet, the armature
secondly mentioned being stationary and adjustable when a pivotted or swinging
solenoid or sucking magnet and electro-magnet is employed, and movable when the
latter is fixed, in which case the armature first mentioned is or may be connected
to the other armature, the two forming in fact a compound armature; but I prefer
in both cases to pivot the feed controlling armature to the solenoid or sucking
magnet This part of my invention is illustrated in figures 3, 4, 5, and 6 of the
accompanying drawing in which.
Figure 3 is a side elevation of one form of electric lamp embodying the above
features, and
Figure 4 an end elevation of the same, partly in section on the line x 21
figure 3.
Figure 5 is a side elevation of a modified form of electric lamp and
Figure 6 an end elevation of the same, partly in section on the line y, y,
figure 5.
It will be seen that the two forms of lamps herewith referred to and illustrated
in the accompanying drawing are somewhat similar to two of the forms of lamps
illustrated and described in my said former specification, with the exception of the
feed controlling mechanism. In figures 3 and 4 which represent a lamp in which
the solenoid or sucking magnet swings or turns, A represents the latter, arranged
in a shunt circuit between the terminals F F of the lamp and supported by the
pivots or screws C, C', in the frame B. E and H represent the upper and lower
carbons respectively, G the lower carbon-holder, c the projecting point or knife-edge
or gripping device for supporting the upper carbon, b the mass of soft iron attached
in any convenient manner to the solenoid or sucking magnet; b¹ the armature
controlling the carbon separating mechanism, f. f. f, f the guiding and contact
rollers, each pair of which have their axles connected by springs, as shown, g, g' the
screw or stop bolts, h the conductor for completing the circuit from the lower
carbon-holder to the insulated terminal F', and p the adjustable spring for turning
the solenoid or sucking magnet, lifting the upper carbon and striking the arc, all
of which are identical with the parts similarly lettered in my said former
specification. a represents one form and arrangement of my new feed controlling
armature, pivotted at a' and carrying the insulated projecting point or knife-edge c
as shown. A frame n provided with a pin or spindle n' (partially screw-threaded)
carries a spiral spring o which presses against one side of the said feed controlling

page_text: armature a and presses the projecting point or knife edge c into contact with the
upper carbon with a force which may be regulated by means of the nut n³. The
form of feed controlling armature, the method of supporting it and the manner in
which it is kept in contact with the upper carbon may obviously be greatly varied
without departing from the nature of my invention. For instance, the armature
may consist of a mass of soft iron attached to a leaf spring as in the make and
break device common in ordinary induction coils, and instead of the spring o
pressing directly on one side of the armature it may press on one end of a short
core attached to one side of the armature and partly within the hollow centre of
the solenoid or sucking magnet.
The lamp operates in the following manner, namely:-The carbons being apart
in the first instance and the current switched on, it passes through the shunt
solenoid or sucking magnet, magnetising the mass b of soft iron which attracts the
feed controlling armature a with the projection or knife edge c against the pressure
of the spring o and allowing the upper carbon to fall and come in contact with the
lower carbon. At the same time the mass b, being magnetised, tends to attract
the armature b¹ but since the latter is fixed the solenoid or sucking magnet is
attracted towards it and so turns or swings on its pivotted axis through a small
arc against the action of the spring p. The carbons being now in contact the
current is nearly wholly diverted from the solenoid or sucking magnet and passes
through the carbons, whereupon, the pivotted feed controlling armature being no
longer sufficiently attracted by the mass b, the spring o immediately forces it out
into contact with the upper carbon, while the spring p pulls the solenoid or
sucking magnet into a horizontal or nearly horizontal position and into contact
with the stop screw g, at the same time lifting the upper carbon, which is now
held by the projection or knife edge c, a short distance, and striking the arc, the
length of which is determined by the suitable adjustment of the armature b¹ and
screws g, g¹. As the carbons gradually burn away the resistance of the arc
increases when more of the current necessarily passes through the solenoid or
sucking magnet attracting the pivotted feed controlling armature to a greater or
less extent, and allowing the upper carbon to descend a little. This continued and
rapidly recurring action of the solenoid or sucking magnet causes the lamp to burn
steadily whilst in use.
In figures 5 and 6 I have shown the pivotted feed controlling armature a
combined with the modified form of lamp in which the solenoid or sucking
magnet A is fixed, while the armature 6 controlling the carbon separating
mechanism is movable. In this modified form of lamp now shown, the pivotted
feed controlling armature a replaces the core a shown and described in my said
former specification, with reference to the figures illustrating a similar form of lamp,
while in all other other respects the modification of lamp now shown is identical
with that therein shown and described, and therefore will be readily understood
without further description.
I also apply the pivotted feed controlling armature a to the other modifications
of electric lamps shown and described in my said former specification, namely, the
modification in which both the upper and lower carbons are movable, the modifi-
cation in which the solenoid or sucking magnet arrangement instead of regulating
the descent of the upper electrode, which tends to fall by gravitation, may be
employed to regulate the ascent of the lower electrode, which may have a tendency
to rise imparted to it by means of a spring or counterweight or other suitable
device, and the modification in which the carbons or electrodes are arranged
horizontally; in each case the core of the solenoid or sucking magnet therein
described being replaced by the pivotted feed controlling armature a substantially
as above described and in a manner that will be readily understood from the
examples herein shown and described.
I may replace the core berein shown and described with reference to figures 1
and 2 (in which the solenoid or sucking magnet is arranged in the main circuit)
by the employment of the pivotted feed controlling armature a the same being

page_text: combined and arranged with the other parts of the lamp in a manner that will be
readily understood.
The armature whether fixed or movable which controls the carbon separating
mechanism may be duplicated if desired, and arranged at opposite ends of the
solenoid or sucking magnet.
Having thus fully described my said invention and shown how the same is or
may be used or carried into effect, what I claim is :-
First. In an electric arc lamp, the employment in regulating the feed of the
carbon or carbons or electrodes, separating the carbons or electrodes and striking
the arc, of a pivotted or swinging solenoid or sucking magnet, arranged in the
main circuit of the lamp, and having its movable core acting directly on one of the
carbons or electrodes substantially as hereinbefore described.
Second. In an electric are lamp, the employment in regulating the feed of the
carbon or carbons or electrodes, separating the carbons or electrodes and striking
the arc, of a pivotted or swinging solenoid or sucking magnet, arranged as a shunt
or derived circuit between the terminals of the lamp, and having its pivotted feed
controlling armature acting directly on one of the carbons or electrodes substantially
as hereinbefore described.
Third. In an electric arc lamp the employment of a combined solenoid or
sucking magnet and electro-magnet, in regulating the feed, separating the carbons
or electrodes and striking the arc, substantially as herein before described.
Fourth. In an electric arc lamp the employment of a combined solenoid or
sucking magnet and electro-magnet, the pivotted feed controlling armature of
which carries a gripping device acting upon one of the carbons or electrodes to
regulate the feed, whilst the armature controlling the carbon separating mechanism
brings the said gripping device into a position to separate the carbons or electrodes
and form the arc substantially as hereinbefore described.
Fifth. In an electric arc lamp the employment of a combined solenoid or
sucking magnet and electro-magnet controlling by one of its pivotted armatures
the feed of one of the carbons or electrodes and by its other pivotted armature
separating the carbons or electrodes and striking the arc substantially as
hereinbefore described.
Sixth. The general constructions, arrangements and combinations of parts
constituting electric are lamps, substantially as hereinbefore described with
reference to figures 1 and 2, figures 3 and 4 and figures 5 and 6 of the accompanying
drawing.
In Witness whereof I the said James Grieve Lorrain have hereunto set my hand
and seal this third day of August in the year of our Lord one thousand eight
hundred and eighty three.