AN IMPROVED METHOD OF AND APPLIANCE FOR FEEDING THE CARBONS OF ELECTRIC ARC LAMPS
Year: 1883

page_text: LETTERS PATENT to John Henry and Henry Bleckly Bourne both of
80 Grays Inn Road Holborn in the County of Middlesex Electricians for
an Invention of AN IMPROVED METHOD OF AND APPLIANCE FOR FEEDING
THE CARBONS OF ELECTRIC ARC LAMPS
PROVISIONAL SPECIFICATION left by the said John Henry and Henry
Bleckly Bourne at the Office of the Commissioners of Patents on the
7th April 1883.
JOHN HENRY and HENRY BLECKLY BOURNE both of 80 Grays Inn Road
Holborn in the County of Middlesex Electricians AN IMPROVED METHOD OF
AND APPLIANCE FOR FEEDING THE CARBONS OF ELECTRIC ARC LAMPS
The object of our Invention is an improved method of and appliance for causing
the carbons of Electric arc lamps to be fed gradually and in proportion to the
consumption and the exfoliation consequent therefrom, in order to establish and
maintain an uniformity of light and steadiness of flame with clean points during
the burning.
Our Invention is based upon the principle that by a gentle tapping or rapping
at the side of a tube, a rod within and just fitting it can be caused to fall gradually
and in proportion to the force exerted and the rapidity of action coupled with the
weight of the tube and its contents.
For the purposes of our Invention we fit or arrange a magnet and a spring
armature close to the tube or rod which carries say, the upper carbon of an Electric
arc lamp, said spring armature being of the required length and provided with a
button or knob to knock against the carbon-supporting rod or tube at each
pulsation of the armature produced by the flow of the current.
The spring armature is so connected to its support as to be capable of sensitive
adjustment in order to regulate its action to the utmost nicety.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Henry and Henry Bleckly Bourne in the Great Seal Patent
Office on the 6th October 1883.
JOHN HENRY and HENRY BLECKLY BOURNE both of 80 Grays Inn Road
Holborn in the County of Middlesex Electricians. AN IMPROVED METHOD OF
AND APPLIANCE FOR FEEDING THE CARBONS OF ELECTRIC ARC LAMPS
The object of our invention is an improved method of and appliance for causing
the carbons of electric arc lamps to be fed gradually and in proportion to the
consumption and exfoliation consequent therefrom in order to establish and
maintain an uniformity of light and steadiness of flame with clean points during
the burning.
Our invention is based upon the principle that by a gentle tapping or rapping at
the side of a rod which is firmly held in a suitable clutching or gripping device
.said rod can be caused to fall gradually and in proportion to the force exerted and
the rapidity of action coupled with the weight of the rod.
For the purposes of our invention we use any suitable arrangement of electro-
magnet (or solenoid) in combination with a clutch of any convenient form which
separates the carbons thus lighting the lamp and at the same time tightly grips
the carbon holder. Near this carbon holder c we fit or arrange an electro
magnet a and a spring armature b said spring armature 6 being of the required
length and provided with a button or knob d to knock against the carbon sup-
porting rod or tube c at each pulsation of the armature b produced by the
intermittent flow of the current in combination with the contact breaker or
interrupter x, y, or otherwise.
The springh is so connected to its support as to be capable of sensitive
adjustment in order to regulate its action to the utmost nicety.
This electro-magnet is most conveniently wound with fine wire and placed
as a shunt across the arc, it may however in some cases be excited by a separate
and independent current.
Attached to the armature band in electrical connection with it is a contact
piece x. To the spring hand insulated from it by means of washers of suitable
non-conducting material is fixed another contact piece y which is connected by
means of a wire with one end of the coil of the electro magnet a.
The path of the current in this electro magnet is as follows:-starting from the
positive terminal + which is in connection with the frame of the lamp, it passes
down the spring and armature b to the contact piece thence (if x and y are
touching) through y to the coils of the electro magnet a and by means of a wire, to
the negative terminal- Only a small fraction. of the main current goes through
the electro-magnet a owing to its very high resistance.
-.
The solenoid fis not absolutely necessary to our invention if the electro-magnet,
armature, contact breaker, and button for tapping the rod are used without the
solenoid fas at Figure 4. The action of the lamp is as follows:-if the arc is of
the proper length and resistance the current flowing in the electro magnet a will
not cause it to attract the armature b with sufficient force to overcome the tension
of the spring k. When however the resistance of the arc increases more current
At the
will flow through the shunt coils a and the armature b will be attracted
same moment the contact between x and y will be broken, the magnet a will lose
its power, the armature will at once fly back owing to the spring k and cause the
button d to strike the rod c. The contact will now be re-established, the armature

page_text: attracted and so on the button & striking the rod c a number of taps in quick
succession this will cause the rod c to move a minute distance through the above
mentioned clutch till the arc is reduced to its proper length.
This series of actions will go on at frequent intervals during the burning of the
5 lamp.
A lamp thus arranged has however a tendency to over feed owing to the fact
that less current is required to keep the armature 6 in a state of vibration when
once started than is necessary to set it in motion in the first instance, it is for the
purpose of obviating this defect that we introduce into the lamp the solenoid f.
The said solenoid fis provided with a core g which is attached by means of a link
to the lever m which is screwed to the spring h. This solenoid may be upon the
main circuit on a shunt across the arc or it may be wound differentially. In the
figure it is supposed to be on a shunt. The solenoid core g moving under the
influence of the current circulating in its coils (and therefore moving according to
the length of the are and the strength of the springh said spring being capable of
adjustment by means of the screw i) moves the contact piece y in such a manner
as to cause the armature 6 to vibrate or to cease vibrating or to vary its speed of
vibration thus controlling the tapping of the rod and the feeding of the carbons
Instead of the solenoid core g moving the spring hit may operate a separate
contact in the circuit of the electro magnet a. This solenoid may in this case if
found convenient be placed outside the lamp in any suitable position and it must
be provided with an opposing spring or other equivalent device for regulating its
action
The solenoid and core f may be replaced by an electro magnet and armature
said electro magnet being on the main circuit on a shunt across the are or wound
differentially as found most convenient.
Also the electro magnet a and armature b may be replaced by a solenoid and
core.
It is not essential to our invention that the electro magnet (or solenoid) a
should be placed as a shunt across the arc. It may be excited by a separate and
independent current this current may be intermittent the make and break being
produced by any of the well known devices for this purpose or the lamp may be
supplied with alternating currents. In either of the above cases the contact
breaker x, y, may be suppressed and the solenoid (or magnet) ƒ be made to operate
a separate contact in the circuit of the electro magnet (or solenoid) a after the
manner of a relay.
Or the electro-magnet or solenoid a may be placed on the main circuit, in this
case when the armature (or solenoid core) b is attracted instead of breaking contact
at y, a contact must be made which short circuits the magnet (or solenoid) a
that is to say the contact y must be placed on that side of the contact which is
nearest the electro-magnet (or solenoid) a and the contacts x y must be aranged as
a shunt across the terminals of the magnet (or solenoid) a.
"
Whenever in the above description an electro magnet or solenoid is said to be
on the main circuit" it is meant that the coils of said electro magnet or solenoid
are connected in series with the arc.
It is not essential that the button & should strike against the rod c, the saine
effect is produced if it strikes some other part of the lamp provided that the
vibrations set up by the tapping are transmitted to the rod by the frame of the
lamp or otherwise.
Having now described the nature of our said invention and in what manner the
same is to be performed we declare that we claim
First The improved method of and appliance for feeding the carbons of electric
arc lamps substantially as described and shown in the annexed drawings.
Secondly-The combination in an electric arc lanp of a clutch for holding or
sustaining the carbon holding rod or tube with a hammering or tapping
device for feeding the said rod or tube through the clutch substantially
as described and shown in the annexed drawing.

page_text: Thirdly The combination in an electric arc lamp of the above mentioned feeding
device with an electro magnet or solenoid for the purpose of starting or
stopping the same according to the length of the arc
In witness whereof we the said John Henry and Henry Bleckly Bourne have
hereunto set our hands and seals this Fifth day of October in the year of our
Lord one thousand eight hundred and eighty three.
TATA
זוהדד