IMPROVEMENTS IN ELECTRIC-LIGHTING APPARATUS
Year: 1881

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine, Lake,
& Co., Patent Agents, Southampton Buildings, London, for an Invention of
"IMPROVEMENTS IN ELECTRIC-LIGHTING APPARATUS." A communication from
abroad by James John Wood, of the City and State of New York, United
States of America.
PROVISIONAL SPECIFICATION left by the said William Robert Lake at the
Office of the Commissioners of Patents on the 29th June 1881.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent
Agents, Southampton Buildings, London. "IMPROVEMENTS IN ELECTRIC-LIGHTING
APPARATUS." [A communication from abroad by James John Wood, of the City
and State of New York, United States of America.]
This Invention relates to electric-lighting apparatus.
It comprises an arrangement of circuits and devices designed to afford a
conducting path around a faulty lamp when from any cause, such as breakage of
the carbons or failure of the regulating mechanism to act properly, the resistance
in the light or carbon circuit rises above a regulated or determinate amount, thus
interfering with the proper action of other lamps in the same circuit.
The said Invention also comprises certain features of construction hereinafter
described.
The form of lamp in which my Invention is embodied belongs to that general
class in which the feed and regulation of the distance between the carbons is
dependent upon the distribution of currents in two derived circuits, one of which
contains the carbons and the other of which constitutes a branch circuit of high
resistance around the carbons, one or both of the derived circuits containing
electro-magnetic coils or helices for acting upon the regulating devices.
According to the said Invention I place in that one of the derived circuits con-
taining the carbons (which for convenience I shall term the main or light circuit) an
electro-magnetic coil or helix independent of the regulating coil controlling through
suitable devices a second branch or derived circuit, preferably of a resistance

page_text: approximate to that of the arc, said devices being brought into action to close the
branch circuit by any abnormal diminution of the current flowing through the
controlling helix consequent upon an abnormal resistance at the arc. I also
provide a special construction of the cores of the axial electro-magnets contained in
the main or light circuit, and the derived circuit to the same, which serve to give
motion to the regulating mechanism for the purpose of feeding the carbons
together or separating them to form the arc.
I also provide certain improvements in details of construction belonging to the
feeding mechanism proper, and to the electro magnet controlling the electro switch
or circuit closer for the branch safety circuit.
In carrying the said Invention into parctice the coils are mounted in pairs, onc
set being in circuit with the carbons and the other set of high resistance in a
derived circuit around the carbons. These coils are provided with cores attached
to a lever pivotted in the frame, which lever carries the regulating train, and by its
movement separates the carbons or releases the trains in the manner to be
hereinafter described. The said coils oppose one another's attractive effects, and so
long as the arc is of proper length the lever will remain at rest, but upon any
disturbance in the normal distribution of currents in the coils, owing either to the
shortening or lengthening of the arc, the cores will be moved in one direction or
the other to correct the change, the amount of current circulating in the coils
respectively being dependent on the well known law governing the distribution of
the currents in derived circuits. Both pairs of axial magnetic cores are joined to a
common cross piece of iron or other magnetic material, which constitutes a neutral
or bridge portion for each pair and prevents any opposition of magnetic induction
in the cores. The cores may be cut from bar iron, and the cross-piece secured to
them by screws, bolts, or otherwise. Each pair of cores may be constructed with
independent bridge-pieces, and the bridge-pieces themselves joined together. This
construction of the axial magnetic cores and coils gives simplicity and compactness
to the organization, and where the cores and cross piece are cast in one piece
lessens considerably the cost of construction.
The releasing train is mounted in a frame which is pivotted to the axial magnet
lever. This train is of ordinary construction and consists of a toothed wheel
gearing with a rack upon the side of the upper carbon holder, and connected
through a ratchet-wheel pawl, and wheels with a detent wheel and fly. The pawl
allows free upward movement of the carbon-holder, but on the downward
movement of the same the wheel and pawl engage with each other.
A spring secured to a stud projecting downward from the upper plate and
attached at its other end to the frame has a tooth formed by cutting and bending
up a portion of the spring to engage with a wheel and lock the train when the end
of the lever carrying the train is raised. This spring or link is for the purpose of
giving an approximately parallel movement to the frame carrying the wheel-work
which would otherwise on the elevation of that end of the lever upon which it
rests be drawn inward on the arc of a circle towards the carbon-carrier. A
retracting spring attached to the lever is connected with a screw-threaded rod or
spindle by means of a cross pin passing between the spirals. Nuts serve to
adjust the rod and the tension of the spring.
By removing the spring from its attachment to the lever and screwing it up or
down upon the pin one or more turns may be included or excluded from action.
This construction allows of both a coarse and fine adjustment, and renders the
substitution of one spring for another unnecessary.
A dash-pot is attached to the lever for preventing sudden and violent movement.
A stop also attached to the same lever impinges against the heads of the coils so
as to limit its movement.
"
The electro-magnet controlling the branch circuit with a resistance approxi-
mately equal to that of the normal arc is of the form known as axial," and is
provided with a core seated upon a spiral spring resting upon a plate secured by
a screw to the base-plate of the lamp. Upon the same plate and encircling the

page_text: core and spring is a metallic cylinder, embracing the upper portion of which is
a metallic plate or washer connected by a thin spring to the head of the core.
This spring is made as light as possible in order to oppose no obstacle to the free
movement of the core. A bent plate of metal rests upon the head of the magnet
and its end is bent around and over the end of the core so as to form contact
therewith, when the core is forced up by the coiled spring. The bent plate
surrounds the core and metallic cylinder, from which and from the thin spring it
is insulated by vulcanized fibre or other suitable material; the resistance coil is in
the branch or safety circuit.
A binding post is provided for connecting the lamp with the outside circuit,
and is insulated from the frame of the lamp. Another binding post is seated upon
the upper plate of the lamp, and is in metallic contact with the plate and so with
the frame.
Entering, say, at the latter post the current has normally two paths open to it,
one through the frame, the upper carbon-carrier, upper carbon, the arc, the lower
carbon-carrier, which is supported by rods insulated from the plate, clamps, branch
circuit coils, wire, one set of coils, another wire, and to the other post. The second
path is through fine wire helices and to the insulated post. The third path, whichi
is normally broken, but is closed when the branch circuit electro-magnet ceases to
hold the core drawn downward within its convolutions, is through the frame of
the lamp to the plate a core or enclosing cylinder and connection spring to
contacts, bent plate connection, a wire resistance, another wire, and to the insulated
post.
In case the upper carbon fails to free by reason of sticking in the gearing, the
carbons would gradually consume and the circuit become finally broken, thus
interfering with the action of other lamps in the same circuit. To provide for this
and other contingencies, such as breaking of the carbons, I have placed the switch
or branch circuit magnet in the main or light circuit.
The axial magnet is preferred in this connection as it is compact and requires
no extra attachments to the frame as does the ordinary form, so that the general
appearance of the lamp is not marred. Other forms of electro-magnet may;
however, be used.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Robert Lake in the Great Seal Patent Office on the
29th December 1881.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, and Co., Patent
Agents, Southampton Buildings, London. "IMPROVEMENTS IN ELECTRIC LIGHTING
APPARATUS." A communication from abroad by James John Wood, of the City
and State of. New York, United States of America.
This Invention relates to improvements in electric lighting apparatus, and
comprises an arrangement of circuits and devices designed to afford a conducting
path around a faulty lamp when from any cause, such as breakage of the carbons,
or failure of the regulating mechanism to act properly, the resistance in the light
or carbon circuit rises above a regulated or determinate amount, thus interfering
with the proper action of other lamps in the same circuit.
The said Invention also comprises certain features of construction hereinafter
described.
The form of lamp in which my Invention is embodied belongs to that general
class in which the feeding and the regulation of the distance between the carbons
is dependent upon the distribution of currents in two derived circuits, one of which
contains the carbons and the other of which constitutes a branch circuit of high
resistance around the carbons, one or both of the derived circuits containing
electro-magnetic coils or helices for acting upon the regulating devices.
According to the said Invention I place in that one of the derived circuits con-
taining the carbons (which for convenience I shall term the main or light circuit)
an electro-magnetic coil or helix, independent of the regulating coil, controlling
through suitable devices a second branch or derived circuit, preferably of a resistance
approximate to that of the arc, the said devices being brought into action to close
the branch circuit by any abnormal diminution of the current flowing through the
controlling helix, consequent upon an abnormal resistance at the arc. I also
provide a special construction of the cores of the axial electro-magnets contained
in the main or light circuit and the derived circuit to the same, which serve to give
motion to the regulating mechanism for the purpose of feeding the carbons together
or separating them to form the arc. I also provide certain improved details of
construction relating to the feeding mechanism proper and to the electro-magnet
controlling the electric-switch or circuit-closer for the branch safety circuit.
In the accompanying Drawing,
Figure 1 represents a side view of a lamp containing my Invention, a portion of
the frame being removed and the switch-magnet being shown in partial section.
Figure 2 is an end view of the axial electro-magnets in the main and derived
circuits, and their moving cores.
Figure 3 shews the form of a blank used in forming the circuit-closing point
attached to the end of the axial electro-magnet in the main or light circuit which
controls the branch safety circuit.
A and B represent the bottom and top plates of the lamp upon which are
mounted the coils M and S in pairs, the coils M being in circuit with the carbons
and the coils S of high resistance in a derived circuit around the carbons. These
coils are provided with cores E and D, attached to the lever F pivotted at G in the
frame P, which lever carries the regulating train, and by its movement separates
the carbons or releases the trains in the manner to be herein after described. The
said coils M and S oppose one another's attractive effects, and so long as the arc is
of proper length the lever will remain at rest, but upon any disturbance in the
normal distribution of currents in the coils, owing either to the shortening or
lengthening of the arc, the cores will be moved in one direction or the other to

page_text: correct the change, the amount of current circulating in the coils M and S, being
dependent on the well known law governing the distribution of the currents in
derived circuits. As shewn in Figure 2, both pairs of axial magnetic cores are
joined to a common cross-piece 2 of iron or other magnetic inaterial, which
constitutes a neutral or bridge-portion for each pair, and prevents any opposition of
magnetic induction in the cores. The cores may be cut from bar-iron, and the cross-
piece 2 secured to thein by screws, bolts, or otherwise. Each pair of cores may be
constructed with independent bridge-pieces, and the said bridge-pieces themselves
joined together if desired. This construction of the axial magnetic cores and coils.
gives simplicity and compactness to the organisation, and where the cores and
cross-piece are cast in one piece lessens considerably the cost of construction.
The releasing train is shewn as mounted in a frame H, which is pivoted at the
point 3 to the forked axial magnet-lever F. This train is of ordinary construction
and consists, as is shewn, of a toothed wheel gearing with a rack upon the sido of
the upper carbon-holder K, and connected through the ratchet-wheel G, the pawl 7,
and the wheels 8 and 9, with a detent-wheel 4, and fly 5. The pawl 7 allows a
free upward movement of the carbon-holder, but on the downward movement of
the same the wheel 6 and the pawl 7 engage with each other.
A spring or link 12, secured at one end to a stud 13, projecting downward from
the upper plate B and attached at its other end at 14 to the frame H, has a tooth
or detent & formed upon it by cutting and bending up a portion of the said spring
to engage with the wheel 4 and lock the train, when the end of the lever carrying
the said train is raised. This spring or link 12 is for the purpose of giving an
approximately parallel movement to the frame carrying the wheel-work, which
would otherwise on the elevation of that end of the lever upon which it rests be
drawn inward on the arc of a circle towards the carbon-carrier. A retracting
spring g attached to the lever F is connected with the screw-threaded rod or
epindle h, by means of a cross-pin m passing between the spirals of the said springs.
Nuts T, T, serve to adjust the said rod h, and the tension of the spring. By
removing the spring g from its attachment to the lever F and screwing it up or
down upon pin m, one or more turns may be included in or. excluded from action.
This construction allows of both a coarse and a fine adjustment, and renders the
substitution of one spring for another unnecessary.
A dash-pot 41 is attached to the lever F for preventing sudden and violent
movement. A stop 42 also attached to the same lever impinges against the heads
of the coils M or S so as to limit its movement.
The electro-magnet controlling the branch circuit with a resistance approximately
equal to that of the normal are is shewn at R. This electro-magnet is of the form
known as "axial," and is provided with a core 15 seated upon a spiral spring
resting upon the plate n secured by a screw to the base-plate of the lamp. Upon
the same plate n and encircling the core and spring is a metallic cylinder 20,
embracing the upper portion of which is a metallic plate or washer connected by a
thin spring 21 to the head of the core. This spring is made as light as possible in
order to oppose no obstacle to the free movement of the core. A bent plate x of
metal rests upon the head of the magnet, and its end is bent around and over the
end of the core so as to form contact therewith when the core is forced up by the
coiled spring. The plate x surrounds the core and metallic cylinder, from which
and from the thin spring or connection 21 it is insulated by vulcanized fibre or
other suitable material; W represents the resistance-coil in the branch or safety
circuit controlled by R.
The binding post I is provided for connecting the lamp with the outside circuit,
and, as shewn, is insulated from the frame of the lamp. The other binding post
not shewn is seated upon the upper plate of the lamp, and is in metallic contact
with the plate, and so with the frame.
Entering, say, at the latter post, the current has normally two paths open to it,
one through the frame, the upper carbon-carrier, upper carbon, the arc, the lower
carbon-carrier, which is supported by rods 34 insulated as shewn from the plate A,

page_text: the clamps 32, the coils R, the wire 26, the coils M, the wire 25, and to post I.
The second path is through the fine wire helices S, and to the insulated post I.
The third path which is normally broken but is closed when the electro-magnet R
ceases to hold the core 15 drawn downward within its convolutions is through the
frame of the lamp, to the plate n, the core 15, or enclosing cylinder, and connection
or spring 21 to the contact pieces y¹, 3, the connection x, the wire 37, the
resistance W, the wire 35, and to insulated post I.
The general operation of the lamp is as follows, that is to say, while the arc is
of the proper adjusted length the current divides between the helices M, M,
and S, S, in the inverse proportion of the resistance of the circuits in which they
are placed. The resistance in the coils themselves and their circuits are so
proportioned, and the spring g is adjusted to such a tension, that the attractive
effect in the coils M will under these circumstances preponderate over that in the
coils S, and the end of the lever F carrying the train will be held in an elevated-
position with the wheel 4 in engagement with the detent b. The carbon-carrier,
rack, and connected gearing are thus held from movement. The core 15 of the
coils R in the carbon circuit is also held down against the action of the coiled
spring upon which it is seated, and the branch or safety circuit. in which the
resistance W is included is broken at the points y', y.
As the carbons burn away the resistance at the arc increases and the attractive
force in the coils M decreases, while those of S correspondingly increase, and as a
consequence, the end of the lever carrying the train is gradually drawn down by
the action of the retracting spring g, thereby gradually lowering the train and the
connected carbon-carrier until the detent b and the wheel 4 are disengaged. The
connected gearing is then free to rotate by the action of the gravitating carbon-
carrier, and the upper carbon is carried downward towards the lower one until the
arc is shortened and the resistance so far lessened that the coils M again draw
down the lever, and bring the toothed wheel and detent into engagement with
each other.
Should the current strength in the general circuit increase, the arc will be
correspondingly lengthened, the cores E being drawn further within the coils M,
thereby still further raising the releasing train. To this action the detent opposes
no fixed obstacle since it is attached to the yielding spring.
In case the upper carbon fails to free itself by reason of sticking in the gearing,
the carbons would gradually consume and the circuit become finally broken, thus
interfering with the action of other lamps in the same circuit. To provide for
this and other contingencies, such as breaking of the carbons, I have placed the
switch-magnet R in the main or light circuit. So long as the proper action of the
arc continues the branch or safety circuit is broken, but upon the breaking of the
light or carbon circuit or the occurence of an abnormally great resistance,
the coils R cease to exert a sufficiently attractive effect upon the core 15 to hold it
depressed. The coil-spring thereupon raises the core into contact with the point y
and gradually the branch or safety circuit through the resistance coil W is closed.
If the difficulty arises from breakage of the carbons or from a sudden and marked
decrease in current strength in the general circuit, the carbons will be gradually
fed until they come into contact and re-establish the main or light circuit. The
coils M will thereupon act to raise the train and upper carrier to re-form the arc, and
simultaneously the coils R will act upon the core 15 and break the branch or
safety circuit.
The electro-magnetic switch R acts with certainty and promptness owing to the
fact that it is in the main or light circuit, and is subjected to the action of the
current passing through the arc. It requires but few convolutions of large sized
wire, a circumstance that facilitates the construction and lessens the cost. The
axial magnet is preferred in this connection as it is compact and requires no extra
attachments to the frame as the ordinary form does, so that the general appearance
of the lamp is not marred. Other forms of electro-magnet may however be
employed if desired.

page_text: Having thus fully described the said Invention, as communicated to me by
my foreign correspondent, and the manner of performing the same, I wish it
understood that I claim,-
First. The combination with an electric light regulator constructed with a
constantly closed branch or derived circuit around the carbons of an electro-
magnetic switch in the main or light circuit between the points of deviation, and
controlling through suitable contacts a branch or safety circuit around the lamp,
for the purposes specified:
Second. In an electric lamp constructed with two derived circuits, one con-
taining the carbons and electro-magnetic coils acting upon the regulating
mechanism, and the other of high resistance containing electro-magnetic coils
acting in opposition to those in the main or high circuit, an electro-magnetic
switch located in the said main or light circuit, and provided with contacts
controlling a branch circuit containing a resistance approximately equal to that of
the normal arc, for the purposes specified.
Third. In an electric light regulator provided with regulating mechanism under
the joint control of electro-magnetic helices placed in the main or light circuit, and
in a derived circuit thereto respectively an axial electro-magnet in the main or
light circuit between the points of deviation, the movable core of which controls a
branch or safety circuit around the lamp.
Fourth. In an electric light regulator constructed to offer two conducting paths
to the current, an axial electro-magnet placed in the main or light circuit, and
provided with a movable core seated upon a coiled spring in combination with
contacts controlling a branch or safety circuit around the lamp of a resistance,
approximately equal to that of the normal arc.
Fifth. An axial electro-magnetic circuit closer consisting of electro-magnetic coils
or helices, and a movable core provided with a contact in combination with a
metallic plate seated upon the head of the said coils, and bent around to form
a circuit-closing point to act in conjunction with the core, for the purposes
specified.
Sixth. In an axial electro-magnetic switch, a movable core and supporting spring
in combination with a supporting metallic plate and an enclosing metallic cylinder,
substantially as above set forth.
Seventh. In an axial electro-magnetic switch the combination of a movable core,
an enclosing metallic cylinder, and a flexible electrical connection from the said
cylinder to the core, for the purpose specified.
Eighth. In an axial electro-magnetic switch the combination of a movable
metallic plate bent to form a circuit-closer for the core, and seated upon the head
of the coils an enclosing metallic cylinder for the said core, and a flexible
electrical connection from the end of the core to the cylinder, substantially as above
set forth.
Ninth. The two pairs of axial magnetic-cores joined by a common bridge or
cross-piece in combination with coils or helices in the main or light circuit
and a derived circuit thereto, substantially as above set forth and for the purpose
specified.
Tenth. The two pairs of axial magnetic cores joined by a bridge or cross-piece of
magnetic material, the whole being cast in one piece (or otherwise constructed),
substantially as above set forth.
Eleventh. In an electric light regulator a releasing train supported and pivoted
in the armature-lever in combination with a parallel motion link carrying a detent
(or equivalent device), for the purpose specified.
Twelfth. In combination with the pivotted core or armature-lever a stop attached
to the said lever, and impinging against the heads of the coils or helices, for the
purpose specified.
Thirteenth. In combination with the adjustable rod or spindle and the retracting
spiral spring a connecting device serving to bring more or less of the helices of the
said spring into action, for the purposes specified.

page_text: Fourteenth. In combination with the spiral retracting spring the adjustable rod
or spindle provided with transverse pins or projections to serve as a means of
attachment for the spring, for the purpose specified.
In witness whereof, I, the said William Robert Lake, have hereunto set my
hand and seal, this Twenty ninth day of December, in the year of our
Lord One thousand eight hundred and eighty one.
TIT
ROB. LAKE.
(.....)