IMPROVEMENTS IN ELECTRIC LAMPS OF THE ARC TYPE
Year: 1883

page_text: LETTERS PATENT to Frederick John Cheesbrough of the Office for Patents
15 Water Street Liverpool in the County of Lancaster Consulting Engineer.
for an Invention of IMPROVEMENTS IN ELECTRIC LAMPS OF THE ARC TYPE
communicated to him from abroad by Edward R Knowles of Brooklyn in
the County of Kings State of New York United States of America
PROVISIONAL SPECIFICATION left by the said Frederick John Cheesbrough
at the Office of the Commissioners of Patents on the 1st January 1883.
FREDERICK JOHN CHEESBROUGH, of the office for Patents, 15 Water Street
Liverpool in the County of Lancaster, Consulting Engineer. "IMPROVEMENTS
IN ELECTRIC LAMPS OF THE ARC TYPE." [Communicated to him from abroad by
Edward R. Knowles of Brooklyn in the County of Kings State of New York
United States of America]
This Invention consists of certain mechanical improvements in the construction
of the lamp and in the application of the circuits thereto. The construction of
the lamp and its machinery will be readily understood from the following
description
According to this Invention there are used two electro magnets hereafter called
the first and second mounted on a frame: one of these magnets the second is
divided into four sections; each of which is coiled full of wire wound in the same
way, the inside ends of all the coils being joined together as are also all the
outside ends making the quantitive magnet of Professor Henry. It is known that
the power of a magnet depends upon the size of the wire with which it is wound
and the number of convolutions within certain limits. When a magnet is coiled
with a coarse wire, the convolutions do not fill all the space stock, the same as if
wound with a fine wire. But by taking a number of small wires the sum of whose
areas equel that of a given coarse wire and winding each one on separately and
then connecting their ends, a much greated number of convolutions can be put
over the magnet, while the total metal area will be the same, so that a much
greater magnetic effect can be obtained by the arrangement of fine wire than by

page_text: the ordinary winding with coarse wire. This magnet, as such, is not new but by
combining it with the lighting circuit of an electric lamp to work its machinery, a
much smaller magnet can be used, while at the same time much greater magnetic
force can be obtained and the resistance of the circuit materially decreased
The other magnet is wound with very fine wire and the two magnets are
connected so that a differential action is set up, the magnetism of the first magnet
pulling against the magnetism of the second the two being so connected in circuit
that about one per cent of the current passes through the first magnet and all the
rest through the second magnet
There is a rocking lever connected at its ends to the moveable magnet cores by
pins passing through oblong holes in the ends of the lever, said lever is also
pivotted to the frame through an oblong hole in the lever The ends of this lever
embrace the ends of the cores and through it the rod also passes
There is a rod that carries the upper carbon holder and the carbons held by
means of screws The rod passes through long cylindrical bearings forming part of
the frame and also through the lever
Pivotted in this lever is a clutch lever the end of which carries a hollow
receptacle supplied with mercury, the amount of which can be adjusted to the
weight required on the lever the end of the clutch lever being prevented from
rising up above the main lever by a stop
There is a set screw against which the weight receptacle abutts when the lamp
is not in action the object of which is to release the rod from the clutch lever the
moment the circuit is disrupted The object of this arrangement of the lever
with the magnet cores and the other connecting parts is to work or operate the
upper carbon
There are two adjustable contact points insulated from the frame and the lever
and tipped with platinum
In the top of the lamp case is inserted a tube in the top of which a ring is
inserted by which the lamp is suspended
Insido of the tube a weight is placed in the form of a ring and made to embrace
the rod This weight is arranged to slide freely up and down in the tube and upon
the rod to which it is attached by means of cords or chains passing over pulleys the
object of this weight being to counterbalance the weight of the rod By these
means much less magnetic force is made necessary to operate the upper electrode
and its holder for its weight being balanced by another weight a very small magnet
is all that is necessary to operate it
The frame that carries the magnets and the rocking lever is secured to another
frame by screws
To the upper carbon holder is attached a catch hook and to the lower side of the
lamp frame is bolted or fixed a bracket into which the hook catches when the rod
is shoved up and by which the electrodes are kept apart when the lamp is not
in use
The base of the lamp is connected to the frame by means of rods which are
insulated
In the base piece are set two circular plates having shoulders-One plate is set
eccentrically and the other centrally the two being held by a plate and screws
The tube carrying the lower carbon holder and carbon is set centrally in the plate
and on the outer side of these plates are projecting pins to which a wrench can be
applied to adjust the plates with reference to each other By means of this device
the lower carbon can be adjusted to centre exactly under the upper carbon The tube
is of course fastened in the plate and swings with it in the other plate the two
plates being adjustable with reference to each other by which the carbon point is
brought in its proper position
The glass globe is held by a plate slipped on the tube and held by a set screw
the stopper being removeable to allow the plate to be slipped on to the tube By
these means the globe can be adjusted over the carbons to the desired position and
can be readily removed to take out some carbon and put in another

page_text: The electrical connections are as follows the main circuit conductor comes to the
binding posts, the currents enter at the + points and divides one part passing
through the second magnet, rod carbons base rod and wire to the point the other
parts going through contact points to first magnet through first magnet to
the point thus making two closed circuits one through second magnet and the
lamp and the other through the first magnet and the terminals of the lamp the first
magnet being cut out when the lamp is not in action by contact points which takes
place the instant the circuit in the first magnet is broken by which the core is
released and the lever dropped by which the second point is brought in contact with
the first point short circuiting both the lamp and magnet
-
The action of the lamp is as follows: The current enters at the + point and
divides part going through and energising second magnet thence through the
carbons to the side This causes the second magnet to draw in the core and lift
the lever as the lever is lifted, the weight causes the hook to fall and clutch the rod
between the cam and the side of the hole in the lever and as the core continues to
lift the rod held by the cam lever the carbon points are separated and the arc
establishes The other part of the current passes to one contact point through the
coil of the first magnet through a wire, the other contact point and other wires to
the point thus also energising the first magnet which tends to pull in the core
but as the first magnet is of very low resistance the magnetism of the second
magnet overcomes that of the first magnet and the lever is lifted against the pull
of the latter magnet Before the lever is lifted the current is short circuited around
the first magnet of the contact points but as soon as the lever is lifted by the core
the contact between the contact points is broken and the current passes through
the coil of the first magnet thus making a continuously closed circuit through cach
magnet when the lamp is in operation one of high and one of low resistance and
both of which continue closed during the normal operation of the lamp
Now as the arc increases in length the resistance increases in the circuit through
the lamp thus decreasing the magnetism of the second magnet, while that of the
first magnet increases, thus varying the pull on the lever, which gradually falls
until the weight comes in contact with the set screw by which the cam is made to
release the rod and allow it to fall sufficiently to re establish the proper length of
arc The lever is then again instantly raised and the can clutches and holds tho
rod as before All these movements are of course gradual so that the rod really
continually falls slowly as fast as the carbons are consumed
In case it is desired at any time to cut a lamp out of circuit the upper carbon
rod is pushed up until the hook catches on the bracket by which the circuit is
disrupted the current then going through the contact points around the first magnet
to the next lamp in circuit

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Frederick John Cheesbrough in the Great Seal Patent Office
on the 29th June 1883.
FREDERICK JOHN CHEESBROUGH, of the Office for Patents, 15, Water Street,
Liverpool, in the County of Lancaster, Consulting Engineer "IMPROVEMENTS
IN ELECTRIC LAMPS OF THE ARC TYPE" A Communication to me from abroad
by Edward R. Knowles, of Brooklyn, in the County of Kings, State of New York
United States of America.
The following is a description of the Invention in such full, clear, concise and
exact terms as will enable any one skilled in the art to which it appertains, or with
which it is most nearly connected to make and use the same, reference being had
to the accompanying Drawings making part of this Specification, in which Figure 1
is a vertical section through the completed lamp, having these improvements
applied thereto, and Figures 2, 3. 4. 5. 6 and 7, are parts in detail to be hereinafter
described
This Invention consists of certain mechanical improvements in the construction
of the lamp and in the application of the circuits thereto. The construction of
the lamp and its machinery will be readily understood from the following
description and the points of novelty consistuting [sic] the improvements will be
designated in the claims concluding this Specification.
Reference being had to the Drawing A and A' are two electro magnets mounted
on the frame E; the magnet A¹ is divided into sections 1. 2. 3. 4, each of which is
coiled full of wire wound in the same way the inside ends of all the coils being
joined together as are also all the outside ends making the quantative magnet of
Professor Henry. It is known that the power of a magnet depends upon the size
of the wire with which it is wound and the number of convolutions within certain
limits. When a magnet is coiled with a coarso wire the convolutions do not fill all
the space stock the same as if wound with a fine wire. But by taking a number of
small wires, the sum of whose areas equal that of a given coarse wire and winding
each one on separately and then connecting their ends as described a much greater
number of convolutions can be put over the magnet, while the total metal area will
be the same, so that a much greater magnetic effect can be obtained by the arrange-
ment of fine wire than by the ordinary winding with coarse wire. This magnet,
as such is not new, but by combining it with the lighting circuit of an electric
lamp to work its machinery a much smaller magnet can be used, while at the same
time, much greater magnetic force can be obtained and the resistance of the circuit
materially decreased.
The magnet A is wound with very fine wire and the two magnets A and A' are
connected so that a differential action is set up the magnetism of A pulling against
the magnetism of A', the two being so connected in circuit that about one per cent
of the current passes through A and all the rest through A¹.
G is a rocking lever connected at its ends to the movable magnet cores B and B'
by pins P¹ and P³ passing through oblong holes J and J' made in the ends of the
lever; said lever is also pivotted to the frame E at P' through an oblong hole J' in
Baid lever. The ends of this lever embrace the ends of the cores B and B¹ and
through it the rod D also passes as shown in Figure 4.
D is a rod that carries the upper carbon holder H' and carbons C' held by means
of screws S. The rod D passes through long cylindrical bearings H H forming
part of the frame E and also through the lever G as above described.
Pivotted in the lever G at P is a clutch lever F the end of which carries a

page_text: hollow receptacle M supplied with mercury the amount of which can be adjusted
to the weight required on the lever, the end of the lever being prevented from
raising up above the lever G by a stop 9 in the manner shown. The stop 9 may
be of any suitable construction such as a pin. Its object is to prevent the cam
lever F rising above the rocking lever G in which position it might stick and
prevent the carbon being pushed up, or down.
S³ is a set screw against which the weight M abuts when the lamp is not in
action, the object of which is to release the rod D from the clutch lever F, the
moment the circuit is disrupted. The object of this arrangement of the lever G
with the magnet cores B and B' and the other connecting parts is to work, or
operate the upper carbon as will be hereinafter explained. Modifications of
substantially the same combination of devices for the same purpose are shown by
Figures 5. 6 and 7 of the Drawing.
S and S are two adjustable contact points insulated from E and G and tipped
with platinum 5 and 6.
In the top of the lamp case K is inserted a tube U in the top of which a ring R'
is inserted by which the lamp is suspended.
Inside of the tube U a weight V is placed in the form of a ring and made to
embrace the rod D. This weight is arranged to slide freely up and down in the
tube and upon the rod to which it is attached by means of cords, or chains CC
passing over pulleys 7 and 8, a suitable revolving connection being made on the
top of the rod D to prevent torsion in the cords or chains CC when the upper
electrode C is turned round. The object of the weight being to counterbalance
the weight of the rod D By these means much less magnetic force is made
necessary to operate the upper electrode and its holder, for its weight being
balanced by the weight V a very small magnet is all that is necessary to
operate it.
The frame E that carries the magnets A and A' and the rocking lever G is
secured to the frame L by the screws S S.
To the upper carbon holder H' is attached a catch hook 11 and to the lower
side of the lamp frame L is bolted, or fixed a bracket 10 into which the hook 11
catches when the rod D is shoved up and by which the electrodes are kept apart
when the lamp is not in use.
The base M of the lamp is connected to the frame L by means of rods R R
insulated at I' I' and 1³.
In the base piece M are set two circular plates O and P having shoulders as
shown. The plate P is set eccentrically in O and O is set centrally in M³, the two
being held by a plate N and screws 1. The tube R' carrying the lower carbon
holder Hand carbon C¹ is set centrally in the plate O and on the outer side of
these plates O and P are projecting pins t t. to which a wrench can be applied to
adjust the plates with reference to each other. By means of this device the lower
carbon C can be adjusted to centre exactly under the upper carbon. The
arrangement is fully shown in Figures 2 and 3. The tube R' is of course fastened
in the plate P and swings with it in the plate O, the two plates being adjustable
with reference to each other by which the carbon point is brought in its proper
position.
The glass globe G¹ is held by a plate Q slipped on the tube R' and held by a set
screw St, the stopper C being removable to allow the plate to be slipped onto the
tube in the manner shown. By these means the globe can be adjusted over the
carbons to the desired position and can be readily removed to take out one carbon
and put in another.
The electrical connections are as follows: the main circuit conductor comes to
the binding posts p³ 2, the current enters at the + point and divides one part
passing through the magnet A' to E and rod D carbons C', base M' rod R wire Z
point at p; the other parts going through X, contact points S3 and X' to
magnet A, through magnet A and X' to the point through Z and Y³, thus
making two closed circuits, one through magnet A¹ and the lamp, the other through
to
-
-

page_text: magnet A and the terminals of the lamp, the magnet A' being cut out when the
lamp is not in action by the contact points S³ and S' which takes place the instant
the circuit in the magnet A' is broken, by which the core B' is released and the
lever G dropped by which the point S is brought in contact with the point S³
short circuiting both the lamp and the magnet A.
-
-
The action of the lamp is as follows: the current enters at the + point and
divides, part going through and energizing the magnet A', thenco through the
carbons and R to the side. This causes the magnet A' to draw in the core B¹
and lift the lever G. As G is lifted the weight M causes the hook F to fall and
clutch the rod D between the came and the side of the hole in G and as the core B¹
continues to lift the rod held by the cam lever F, the carbon points are separated
and the arc establish The other part of the current passes to S³ through the
coil of the magnet A through wire X contact S* wire Y and Z to point, thus
also energizing the magnet A which tends to pull in the core B, but as A is of very
high resistance the magnetism of A' overcomes that of A and the lever G is lifted
against the pull of the latter magnet. Before the lever G is lifted, the current is
short circuited around the magnet A by the contact points S³ and S', but as soon
as the lever G is lifted by the core B¹, the contact between the points S³ and S' is
broken and the current passes through the coil of the magnet A, thus making a
continuously closed circuit through each magnet when the lamp is in operation one
of high and one of low resistance, and both of which continue closed during the
norinal operation of the lamp.
Now as the are increases in length the resistance increases in the circuit through
the lamp, thus decreasing the magnetism of A' while that of A increases, thus
varying the pull on the lever G which gradually falls until the weight M comes
in contact with the set screw S by which the cam E is made to release the rod D
and allow it to fall sufficiently to re establish the proper length of arc. The
lever G is then again instantly raised and the cam clutches and holds the rod as
before. All of these movements are of course gradual, so that the rod D really
continually falls slowly as fast as the carbons are consumed.
In case it is desired at any time to cut a lamp out of circuit the upper carbon
rod D is pushed up until the hook 11 catches on the bracket 10 by which the
circuit is disrupted, the current then going through the contact points around the
magnet A to the next lamp in circuit.
Having thus described the several improvements in are lights, what I claim as
the Invention communicated to me by my Foreign Correspondent is:
First In an are electric lamp the combination of a counterweight (V) a tube (U)
pulleys (7 and 8) and connecting cords (C C) with the carbon rod (D) and upon
the lamp case (K) substantially as described for the purpose specified.
Second In an arc electric lamp the combination with the upper carbon rod of a
rocking lever (G) two moving magnet cores (B and B'), a weighted cam lever (F)
contact points (S³ and S') and differential magnets (A and A') electrically con-
nected in circuit and coacting substantially as described to govern the operation of
the lamp.
Third In an are electric lamp the combination of two electro magnets one being
of high resistance and the other being divided in sections and of low resistanco,
and both being connected in circuit of the lamp and combined with a rocking lever
and clutch, common to both of them and also with the upper carbon rod for the
purpose of operating the same.
Fourth In an are electric lamp the combination with the upper carbon rod of a t
lever embracing said rod and a cam lever impinging against it and a position
weight upon said cam lever, the weight and cain lever coacting with the embracing
lever to hold and feed the rod as described.
Fifth In an arc electric lamp the combination with the lower carbon rod, or
holder of adjusting pieces (O P) in the base of the lamp for the purpose of centering 5
the carbons substantially as described.
. Sixth In an are electric lamp the combination upon the lower carbon rod, or

page_text: holder of an adjustable globe holder (Q) by which the globe is readily slid up, or
down, or removed to facilitate the placing of the carbons.
Seventh In an arc electric lamp the combination with the upper carbon rod, or
holder of a hook (11) and bracket (10) substantially as described for the purpose
specified
In Witness whereof, I, the said Frederick John Cheesbrough, have hereunto
set my hand and seal this twenty seventh day of June in the year of our
Lord one thousand eight hundred and eighty three.