IMPROVEMENTS IN ELECTRIC LAMPS."
Year: 1882

page_text: LETTERS PATENT to Sir Charles Tilston Bright, of 20, Bolton Gardens, in the
County of Middlesex, Knight, for an Invention of "IMPROVEMENTS IN
ELECTRIC LAMPS."
PROVISIONAL SPECIFICATION left by the said Sir Charles Tilston Bright
at the Office of the Commissioners of Patents on the 25th January 1882.
Sir CHARLES TILSTON BRIGHT of 20 Bolton Gardens in the County of Middlesex
Knight. IMPROVEMENTS IN ELECTRIC LAMPS.
I employ two electromagnets for separating and regulating the carbons of an
Electric Lamp.
The magnetic action of one end of the first of the electromagnets separates the
carbons to the required lighting distance upon the passage of an electric current.
The other end of this first electromagnet actuates an armature by the movement
of which the second electromagnet is put upon short circuit or neutralised.-The
feed is regulated by the second electromagnet by means of clips or jaws taking
hold of or releasing the upper carbon holder.
The first electromagnet may be placed either in the main or "light" circuit, or
in a shunt of higher resistance. In the former case the armature is so adjusted
that upon any increase in the resistance of the circuit decreasing the force of the
current the second electromagnet is cut out of circuit or neutralised.-In the
latter case the increase of the current produces the same effect.
The carbonholder is hollow but closed near the bottom at a point above its
carbon clip, and from the upper part of a guide through which it descends a fixed
rod passes into it. This rod has a piston at its lower end which reaches to the
level of a bearing plate through which the hollow carbon holder slides.
The hollow carbon bolder is filled or nearly so with glycerine, mercury, oil, or
any other suitable fluid for retarding its descent over the piston.
The piston has a valve opening in one direction which allows of the carbonholder
being readily lifted. When a nonconducting fluid is used in the tube, a strand or
braid of copper wire is used between the movable tube and the guide.

page_text: Another form of my invention consists in employing solenoids, or tubular coils,
in place of the electroinagnets hereinbefore described, and in this case the carbon
holders are made of iron, the upper one being hollow as before and its descent
being retarded by the attractive force exerted by one of the solenoids, through
which it passes, on the passage of an electric current. The separation of the
carbons is effected in this method by the lower carbon being drawn down to the
requisite distance on the electric current passing through the second solenoid, the
lower end of which actuates a movable piece of soft iron passing into it which
serves as a relay or contact maker, in like manner as the armature of the electro-
magnet previously described.-A modification of this consists in placing both of
the solenoids at the upper part of the lamp; in which case an iron sleeve
surrounding the upper carbon holder passes into the first solenoid, and being con-
nected by a nonmagnetic inetal to a rod or cylinder of soft iron entering the
second solenoid is lifted on the passage of an electric current. Or one electromagnet
and one solenoid may be employed.
Instead of retarding the upper carbon holder by means of a fluid as described, a
rack gearing into clockwork mechanism may be used in connexion with the
foregoing system of electrical arrangement.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Sir Charles Tilston Bright in the Great Seal Patent Office on the
21st July 1882.
Sir CHARLES TILSTON BRIGHT of 20 Bolton Gardens in the County of Middlesex,
Knight. IMPROVEMENTS IN ELECTRIC LAMPS.
I employ two electro-magnets for separating and regulating the carbons of an
electric lamp.
The action of one end of the first of the electro-magnets separates the carbons o
the required lighting distance, that is to say, to strike the arc, upon the passage of
the electric current. The other end of this electro-magnet actuates an armature
by the movement of which the second electro-magnet is put upon short circuit, or
is removed from the circuit, or its effect is neutralised by bringing into play a second
coil of wire wound upon it, so that its effective action ceases for a very brief
interval of time. The feed is regulated by this second electromagnet by means of
clips or jaws taking hold of the upper carbon holder, and releasing it when
occasion (as by the consumption of the carbons) renders the feed-action necessary.
The first electro-magnet may be placed either in the main circuit with the light,
or by preference in a secondary circuit, or shunt of much higher resistance.—In the
former case, the armature is so adjusted that upon any increase in the resistance of
the circuit decreasing the force of the current the second electro-magnet is cut out
of the circuit or neutralised. In the latter case the increase of the current passing
through the shunt circuit produces the same effect.
The carbon holder is hollow, but closed near the bottom above the clip or holder
of the carbon. From the upper part of a guide (which may be a tube, or a frame
of any other suitablo form) a rod passes downwards through the carbon holder,
from the top to the level of a bearing plate through which the carbon holder passes
or slides, and at this point, a piston with a valve opening downwards engages
the interior of the tubular carbon holder. The latter is filled, or nearly so, with
glycerine, mercury, oil, or any other suitable fluid for retarding its descent over the
piston.
In cases where great regularity is not essential, as for example in docks, or large
factories, where several lights are used, and a temporary irregularity is not so
perceptible, glycerine or oil is sufficient, but where greater nicety is requisite I
prefer to use mercury, and I insulate the rod down to the piston which I make of
iron. The Carbon holder is also insulated in its interior surface, or it is made of
an insulator such as glass, ebonite, insulite, or other suitable material from the top
down to the bottom where the carbon is taken hold of, at which point it is made
of iron, where in contact with the mercury, and preferably of copper where in
contact with the carbon, or the carbon may enter the carbon-holder so as to be in
contact with the mercury, in which caso the lower part of the holder is made
entirely of iron.
The electrical connexion with the carbon is thus made entirely through the
mercury, the quantity [and therefore the resistance of which] is adapted by the
dimensions of the interior of the carbon holder and of the insulated rod to the
resistance of the carbon. By this arrangement of mercury in my tubular carbon
holder, the regulation of the feed is not affected by the alteration of the resistance
of the carbons arising from their consumption, a corresponding resistance being
added continuously and proportionately by the increasing length of the thin
cylinder of mercury.
When a non-conducting Quid is used in the carbon-holder a braided copper wire

page_text: is used to connect the movable carbon-holder and the frame or guide as shown at
Figs. 3 & 6 in the drawing appended hereto.
Another form of my invention consists in employing solenoids, or tubular coils,
in place of the electro-magnets herein before described and in this case, the carbon
holders are made of iron, the upper one being hollow, as before, and its descent
being retarded by the attractive force of the solenoid through which it passes,
when a current is influencing it.
The separation of the carbons is effected in this part of my invention by the
lower carbon being drawn down to the requisite distance on the electric current
passing through the lower solenoid, the lower end of which actuates a movable
piece of soft iron which passes into it, and which serves as a relay or contact
maker in like manner as the armature of the electro-magnet described in relation
to the first part hereof.
A modification of this consists in placing both of the solenoids in the upper part
of the lamp-In this caso an iron sleeve surrounding the upper carbon holder
passes into the first solenoid, and being connected by a non-magnetic metal to a
rod or cylinder of soft iron entering the second solenoid, is lifted on the passage of
the electric current so as to produce the arc. Or one electro-magnet and one
solenoid may be used.
Instead of using a fluid in the upper carbon holder, a rach may be used on the
outer side of it, gearing into clockwork mechanism to retard the descent of the
carbon in connexion with the system of cutting off the clips or jaws, but I prefer
the method I have described abovo.
Also, instead of the relay arrangements being at one end of the coil by which
the carbons are separated it may be placed at one end of the coil by which the
feed is regulated, which is put out of circuit by short circuiting it, or by breaking
its circuit in the manner of a trembling bell, or bringing another coil wound round
the same electro-magnet-in-an-opposite direction. At Fig 1 in the accompanying
drawing a, a, aro the poles of an electro-magnet in the main circuit-wound with
large wire, b is a ring shaped armature fixed to slide rods c, c, which pass through
the frame of the upper part of the lamp; below the frame, as shown, c c have fixed
to them the plates d, d, which carry the pivotted axles ee of two lovers f which
have at their other onds two armatures g fixed to them. One, only of the lovers,
axles, and armatures are shown, the other one being concealed by it. h, h, are two
electro magnets (covered with fine wire and therefore of high comparative
resistance) which are comprised in a derived circuit shunting the arc.
When the current passes through the two circuits, a a draw up the sliding frame
by attracting b; at the same time g (and the opposite similar armature which is
not seen on the drawing) being attracted by the poles of h h, one of which is
shown at i, grasps hold of the carbon holder jj by jaws at f, and rises with it.
k is an armature fixed to a contact lever which is shown in side view at Fig 2
m, m, in both figures are two poles of electro magnets h h which attract the
armature and thereby bring into contact with the screw n, whenever by the
consumption of the carbon or other cause, the resistance of the arc circuits becomes
greater and in consequence more current passes through h h. land h are respec-
tively connected to the ends of the coils h h, which being thus cut out of circuit
cease to attract g and the armature opposite it which is not seen and the carbon
holder is free to fall. The lever is however, at once brought back by its spring o
to its place of rest, and the jaws again take hold of j j, which is repeated again,
after the manner of the motion of a trembling electric bell, giving an intermittent
feed, until the resistance of the arc is brought to its normal condition, and k is no
more attracted by the poles m m which have adjustable pole pieces of soft iron pp
enabling the action of the relay lever to be adjusted so as to correspond with the
best conditions of resistance for the arc.
At Fig 3. is shown a lamp in which the lower carbon is drawn down by an
electro-magnet, at the lower part of which is seen the contact lever a and its
armature b.

page_text: A side view of the relay arrangement is shown at Fig 4, where a and b
represent the same parts as in figure 3.
The jaws are shown arranged in a different way to the arrangement in Fig 1
at ca point in the upper carbon holder. d is an outer frame, or guide, of the
upper carbon holder; from its upper part, the piston rod and piston descend into
the carbon holder, the position of the piston coinciding with the base plate at e,
(and also as shown at h in fig 6). At fa braided copper wire is used when a non-
conducting fluid is employed to make connexion with the carbon holder at g.
At Fig 5 is shown an arrangement in which two solenoids are a b are used in
place of electro-magnets.
The carbon holder is made of iron, and c is a soft iron sleeve which holds it
when the current is passing through it; it is also lifted up by the soft iron rod d.
The relay arrangement which intermittently cuts off a, is effected by another soft
iron rod and contact maker at f.
In Fig 6 the carbon holder a is also made of soft iron and is held by the
solenoid b when the current is passing. The lower carbon is drawn down in this
form of my lamp by another solenoid c through its action on the soft iron rod d,
another soft iron rod e performing the duty of the armature k and contact lever
of Fig. 1, by being brought into contact with contact pieces ff which momentarily
places b out of circuit, or neutralises it. The upper part of the piston rod is shown
at g, and the dotted lines show its entrance into the carbon holder a which is
closed at the bottom.
The position of the piston is shown at h.
Having thus described the nature of my said Invention and having shown
examples of the best means I am acquainted with of carrying it into effect, I wish
it to be understood that what I claim is;-
First, The regulation of the feed in an electric lamp by the intermittent action
of a contact maker or relay as described.
Second, The carbon holder, piston rod and piston as described.
In witness whereof, I, the said Sir Charles Tilston Bright have hereto set
my hand and seal this Twelfth day of July in the year of our Lord, One
thousand, eight hundred, and eighty two.
m
DATA R