IMPROVEMENTS
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by the said James Brockie at the Office
of the Commissioners of Patents on the 11th April 1882.
JAMES BROCKIE of Brixton in the County of Surrey
ELECTRIC ARC LAMPS
"
"IMPROVEMENTS IN
In all electric arc lamps hitherto constructed, which regulate by the action of a
magnet or solenoid either in a main circuit or in a shunt across the arc or by a
combination of both, the regulating armature or core bears a certain and definite
mechanical relation to the releasing or feeding mechanism (usually a brake or
clutching device) the armature being jointed directly or by levers to the dis-
engaging brake or clutch. Now I propose to do away with this definite or direct
connection and to gear the regulating armature to the brake or other device by
simple friction, or the friction of magnetism, so that the armature is free to take up
various positions in relation to the brake or clutch and yet control it.
I limit the play of the brake or its lever between two stops, this play being
preferably very small, but the regulating armature or core may have a much longer
travel or play; thus it will be seen as above stated, that the armature may take
up various positions in relation to the brake lever, the particular position however
being determined by the strength of the current; thus no alteration in the tension
spring or balance weight acting against the armature is necessary, as the armature
will accommodate its position automatically by the current employed. I have
found by observation that the resistance of an arc is very constant when it is of a
suitable length for the size or quality of the carbons and the strength of the current,
but immediately this length is exceeded in the slightest degree, the resistance
becomes fitful and difficult to measure.
Now, I take advantage of this fitful resistance of the arc to secure the re-adjust-
ment of the carbons, that is to say, when the resistance of the arc becomes

page_text: irregular I cause this very irregularity to produce a mechanical regulating move-
ment, and so long as the resistance remains steady or constant, no movement takes
place. In order to take advantage of this irregularity in the resistance of the arc,
and cause it to produce mechanical action and thereby regulate an electric arc lamp,
I place a solenoid or magnet in a shunt across the arc, the core or armature of
which will vibrate when the arc is variable and remain still when constant. I
cause this core to work an anchor or escapement device which permits the carbons
to approach each other a definite distance at cach vibration, and as long as this
vibratory movement continues, the carbons will be gradually approaching each
other or the distance between them be lessening until the arc regains its stability,
when of course the vibratory movement will cease and the feed be arrosted.
It will be seen that by gearing the solenoid core or magnet armature to the
escapement device above mentioned by means of the frictional method above
explained no alteration in the tension spring would be necessary in such a lamp to
suit variations in current.
Another node of utilizing this unstability of the are for the purposes of adjusting
the carbons is to cause the armature or core of the shunt coil to rotate a wheel by
means of a pawl and ratchet or equivalent means, this said wheel at each revolution
or part of a revolution to make a contact which contact might be made to complete
a branch circuit and this latter to reverse the polarity of the arc-striking or
adjusting magnet in an electric lamp; indeed I propose to use a motor which
would be revolved by the oscillations of au armature due to irregularities in the
resistance of an arc or current in order to effect the re-adjustment of the arcs in
electric lamps, the particular construction of which lamps may be various without
affecting the principle of this part of my invention.

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 11th
October 1882.
JAMES BROCKIE of Brixton in the County of Surrey IMPROVEMENTS
ELECTRIC ARC LAMPS
"
IN
My invention will be best understood by reference to the accompanying
drawings.
Figure 1 is a view of the regulating escapement of an electric arc lamp
constructed according to my invention, Figure 2 shews a complete lamp with
my improvements applied and Figure 3 shews a regulating motor for electric
lamps constructed according to my invention. Similar letters of reference refer
to like parts in all the Figures.
In all electric arc lamps hitherto constructed which regulate by the action of a
magnet or solenoid either in the main circuit or in a shunt across the arc or by a
combination of both; the regulating armature or core bears a certain and definite
mechanical relation to the releasing or feeding mechanism (usually a brake or
clutching device) the armature being jointed directly or by levers to the disengaging
brake or clutch. Now I propose to do away with the definite or direct connection
and to gear the regulating armature to the brake or other device by simple friction
or the friction of magnetism as in Figure 1 so that the armature B is free to take
up various positions in relation to the brake lever C and yet control it. I limit
the play of the brake or its lever between two stops DD this play being preferably
very small but the regulating armature or core B may have a much longer travel
or play thus it will be seen as above stated that the armature may take up
various positions in relation to the brake lever the particular position however
being determined by the strength of the current, thus no alteration in the tension
spring or balance weight acting against the armature is necessary even for much
variation in the current as the armature will accommodate its position automatically
to the current employed.
I have found by observation that the resistance of an arc is very constant when
it is of a suitable length for the size or quality of the carbons and the strength of
the current but immediately this length is exceeded in the slightest degree the
resistance becomes fitful and difficult to measure.
Now I take advantage of this fitful resistance of the arc to secure the readjust-
ment of the carbons, that is to say when the resistance of the arc becomes irregular
I cause this very irregularity to produce a mechanical regulating movement and so
long as the resistance remains steady or constant, no movement takes place. In
order to take advantage of this irregularity in the resistance of the arc and cause
it to produce mechanical action and thereby regulate an electric arc lamp, I place
a solenoid or magnet A in a shunt across the arc as in Figure 2 the core or
armature B of which will vibrate when the resistance of the arc is variable and
remain still when constant I cause this core B to work an anchor or escapement
device C by the friction attachment before described which allows the carbons to
approach each other a definite distance at each vibration by permitting one tooth
of the escape wheel E to pass and as long as this vibratory movement continues,
the carbons will be gradually approaching each other or the distance between them
be lessened until the are regains its stability when of course the vibratory
movement will cease and the feed be arrested. The arc in such a lamp is first
obtained by means of the magnet M drawing down the lower carbon holder N
It will be seen that by gearing or connecting the solenoid core or magnet

page_text: armature B to the escapement device above mentioned by incans of the frictional
method above explained no alteration in the tension spring S is necessary in such
a lamp to suit variatious in current unless thoso variations are very great.
Another mode of utilizing this unstability of the are for the purposes of
adjusting the carbons is to cause the oscillations of the armature or core of the
shunt coil A Figure 3 to rotate a wheel W by means of a pawl and ratchet or
equivalent means this said wheel at each revolution or part of a revolution to make
a contact T which contact might be made to complete a branch circuit and this
latter to reverse the polarity of the arc-striking or adjusting magnet in an electric
lamp; indeed. I propose to use a motor which would be revolved by the oscillations
of an armature due to irregularities in the resistance of an arc or current. In
order to effect the ro-adjustment of the arcs in electric lamps the particular
construction of which lamps may be various without affecting the principle of this
part of my invention
Having now described the nature of my said invention and in what manner the
same is to be perforined I declare that I claim:
First In electric are lamps regulating the distance between the carbons by
means of mechanism actuated by the irregularities in the resistance of the arc in
contra distinction to the method hitherto invariably adopted where the regulation
takes place whon the are becomes of a certain or pre-arranged resistance, all
substantially as hereinbefore set forth.
Second For the purpose of regulating are lamps in accordance with the above
method, the construction of the same, where the core of the regulating coil is
connected by friction or magnetism to the lever of the regulating device, so that
the core may take up various positions in relation to the regulating lever all
substantially as set forth and particularly with reference to Figures 1 and 2 of tho
accompanying drawings.
Third: The construction of motor for the regulation of electric lamps the
movements of which depend upon the irregular resistance of the arc substantially
as described and particularly with reference to Figure 3 of the accompanying
drawings.
In witness whereof I the said James Brockie have hereunto set my hand
and seal this Eleventh day of October in the year of our Lord One
thousand eight hundred and eighty-two :