IMPROVEMENTS IN ELECTRIC ARC LIGHTS
Year: 1881

page_text: LETTERS PATENT to Edward Griffith Brower, of 33, Chancery Lane, in the
County of Middlesex, for an Invention of "IMPROVEMENTS IN ELECTRIC ARC
LIGHTS." A communication from abroad by Thomas Alva Edison; of Menlo
Park, in the State of New Jersey, United States of America.
PROVISIONAL SPECIFICATION loft by the said Edward Griffith Brewer at
the Office of the Commissioners of Patents on the 8th June 1881.
Edward GriffiTII BREWER, of 33, Chancery Lane, in the County of Middlesex.
"IMPROVEMENTS IN ELECTRIC ARC LIGHTS."* (A communication from abroad by
Thomas Alva Edison, of Menlo Park, in the State of New Jersey, United States of
America.)
This Invention relates to electric arc lights using carbon pencils or rods, one or
both of the carbons being fed forward lengthwise, and the object in view is such
an improvement that the arc will remain perfectly steady at all times (except
perhaps for an instant occasionally when the feeding of the carbon or carbons
takes place) and the carbons will be consumed evenly.
This is accomplished by rotating cither or both of the carbon pencils or rods
around the longitudinal axis or axes of the same, the rotating mechanism not
interfering with the feeding of the carbon or carbons.
It has been found necessary
in order to make an absolutely steady arc and secure an even and smooth con-
sumption of the carbon points to rotate one of the carbons at a high speed, as, for
instance, from two to three thousand revolutions per minute, but a higher speed
could be used, and a lower rate of speed might be found under favorable conditions
to answer the purpose.
It is evident that if both carbon pencils are rotated in opposite directions only
half the speed for each would be required.
For rotating one carbon an electro motor may be used of the form of the engine
known as the Pacinuoti engine or of other suitable construction, arranged in the
lamp circuit or in a shunt therefrom, or otherwise suitably connected with the
...

page_text: source of energy; or instead of an electro-motor a spring or weight actuated
mechanism could be used. If both carbons are rotated connections may be made
with one motor or driving mechanism, or a separate motor or driving mechanism
can be used for rotating each carbon.
If a feeding carbon is rotated the metal rod that carries it will be connected with
a revolving part of the motor by a feather or other device, so that the metal rod
can slide freely through the part of the motor that rotates it. The revolving
carbon pencil is preferably secured to its rod by an universal joint (a ball and
socket joint with locking pin and slot answering well for this purpose), and is
guided near its point so that any vibratory or wabbling movement of the metal rod
will not change sensibly the position of the carbon point.
For foeding one or both carbons any mechanism can be used so far as the main
features of this Invention are concerned.
It is preferred, however, to regulate the feed of the upper or positive carbon by
means of an armature through an opening in which the metal holding rod passes.
This armature carries two pawls that clamp the rod and hold it up, the armature
being supported by an electro-magnet in the lamp circuit. When however the
resistance of the lamp circuit is increased to a certain point by the lengthening of
the arc, or when the arc is ruptured, a magnet in a shunt or multiple are circuit
overcomes the first magnet and draws the armature downwardly. The clamping
pawls have arms which strike stops when the armature reaches its lowest position
and throw the pawls away from the holding rod, allowing the carbon to drop.
The magnet in the lamp circuit again becomes the more powerful and stops the
further descent of the carbon, or raises the armature and carbon to re-establish the
arc when ruptured.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Edward Griffith Brewer in the Great Seal Patent Office, on the
8th December 1881.
EDWARD GRIFFITH BREWER, of 33, Chancery Lane, in the County of Middlesex.
"IMPROVEMENTS IN ELECTRIC ARC LIGHTS." A communication from abroad by
Thomas Alva Edison, of Menlo Park, in the State of New Jersey, United States of
America.
This Invention relates to electric-arc lights using carbon pencils or rods, one or
both of the carbons being fed forward lengthwise, and the object in view is such
an improvement that the are will remain perfectly steady at all times (except
perhaps for an instant occasionally when the feeding of the carbon or carbons
takes place) and the carbons will be consumed evenly.
This is accomplished by rotating either or both of the carbon pencils or rods
around the longitudinal axis or axes of the same, the rotating mechanism not
interfering with the feeding of the carbon or carbons.
In order to make an absolutely steady are and secure an even and smooth con-
sumption of the carbon points it is necessary to rotate one of the carbons at a high
speed, as, for instance, from two to three thousand revolutions por minute, but a
higher rate of speed could be used, and a lower speed might be found under
favorable conditions to answer the purpose. It is evident that if both carbon
pencils are rotated in opposite directions only half the speed for each would be
required. For rotating one carbon an electro motor of the Pacinatti or other
suitable construction may be used arranged in the lamp circuit or in a shunt or
derived circuit therefrom, or otherwise suitably connected with the source of
energy; or instead of an electro-motor a spring or weight actuated mechanism
could be used. If both carbons are rotated connections may be made with one
motor or driving mechanism, or a separate motor or driving mechanisın can be used
for rotating each carbon.
If a feeding carbon is rotated the metal rod that carries it will be connected with
A revolving part of the motor by a feather or other device, so that the inetal rod
can slide freely through the part of the motor that rotates it.
The revolving carbon pencil is preferably secured to its rod by an universal
joint (a ball and socket joint with locking pin and slot answering well for this
purpose), and is guided near its point so that any vibrating or wabbling movement
of the metal rod will not change sensibly the position of the carbon point.
For feeding one or both carbons any mechanism can be used so far as the main
features of the Invention are concerned. It is preferred, however, to regulate the
feed of the upper or positive carbon by means of an armature through an opening
in which the metal holding rod passes. This armature carries two pawls that
clamp the rod to hold it up, the armature being supported by an electro-magnet in
the lamp circuit. When however the resistance of the lamp circuit is increased to
a certain point by the lengthening of the arc, or when the arc is ruptured, a magnet
in a shunt or multiple-arc circuit overcomes the first magnet and draws the
armature downwardly. The clamping pawls have arms which strike stops when
the armature reaches its lowest position and throw the pawls away from the
holding rod, allowing the carbon to drop. The magnet in the lamp circuit again
becomes the more powerful and stops the further descent of the carbon, or raises
the armature and carbon to re-establish the are when ruptured.
The preferred manner of carrying out this Invention is shown in the accom-
panying Drawing, in which the Figure represents a side elevation and partial
section of the lamp and regulating mechanism.
A is the frame; B, the lower or negative carbon; and C, the upper or positive
carbon connected with the metal-holding rod D by ball and socket joint " and

page_text: guided near its point by guide b; 1, 2, are the main conductors; E is the electro-
magnet of the motor, the coils of which are in derived circuit 3, 4, and are located
on the frame A on opposite sides of the holding rod D. The revolving armature F
of the motor is supported by sleeve c from top of frame A, through which sleeve
slides the rod D, the rod and sleeve being connected so as to rotate together by
a feather or other suitable device. The commutator springs of the motor are
represented by d, e, while f is the revolving circuit breaker. An adjustable
resistance R is placed in the motor circuit 3, 4, by means of which the speed of the
motor can be regulated.
Gis the horizontal armature lever pivoted on the frame above the motor, and
playing in the fields of two electro-magnets H, I, the movement of the armature
being limited by stops g, h. The magnet H is in the lamp circuit 1, 2, while I is
in motor circuit 3, 4.
The rod D passes through an opening in lever G, such lever being provided with
spring pawls i, k, that clamp downwardly on such rod. The pawls have arms l, m,
and stops n, o, are located at such points on the frame that the pawls are thrown
upwardly away from rod D when the armature lever reaches a certain point in its
downward movement.
What is claimed is,―
First. The method of producing a steady are and ensuring the smooth con-
sumption of the carbons in an electric arc light employing carbon pencils or rods,
consisting in revolving one or both of such carbon pencils or rods, substantially as
set forth.
Second. In an electric arc light the combination of the carbon pencils or rods
with a motor or mechanism for revolving either or both of such carbon pencils or
rods, substantially as set forth.
Third. In an electric are light the combination of the motor or mechanism for
revolving either or both of the carbon pencils or rods with a guide or guides near
the point of the revolving carbon or carbons, substantially as set forth.
Fourth. In an electric arc light the combination with the carbon pencils or rods
of an electro-motor for revolving either or both of the carbon pencils, substantially
as set forth.
Fifth. In an electric are light the combination with a motor or driving
mechanism of a carbon holding rod sliding freely through a part revolved by the
motor but connected so as to turn with such part, and mechanism for controlling
the longitudinal movement of such rod, substantially as and for the purposes set
forth.
Sixth. In an electric are light the combination with the carbon holding rod of
the armature lever playing between two magnets and governing the feed of the
carbon carried by such rod, substantially as set forth.
Seventh. In an electric are light the combination with the carbon-holding rod of
the armature-lever controlled by two magnets connected in multiple arc, such lever
being connected with the holding rod so as to govern its movement, substantially
as set forth.
Eighth. In an electric are light the combination with the rod D of the armature
lever G controlled by magnets H, I, and carrying pawls i, k, having arms l, m, and
the stops n, o, substantially as set forth.
In witness whereof, I, the said Edward Griffith Brewer, have hereunto set my