IMPROVEMENTS IN AND RELATING TO ELECTRIC LAMPS AND SWITCHES THEREFOR
Year: 1879

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 the Invention of "IMPROVEMENTS IN AND RELATING TO ELECTRIC LAMPS
AND SWITCHES THEREFOR." A communication from abroad by William
Edward Sawyer, of New York City, County, and State, United States of
America.
Sealed the 2nd March 1880, and dated the 6th September 1879.
PROVISIONAL SPECIFICATION left by the said Frederick John Cheesbrough
at the Office of the Commissioners of Patents on the 6th September 1879.
FREDERICK JOHN CHEESBROUGH, of the Office for Patents, 15, Water Street,
Liverpool, in the County of Lancaster, Consulting Engineer. "IMPROVEMENTS IN
AND RELATING TO ELECTRIC LAMPS AND SWITCHES THEREFOR." [A communication
from abroad by William Edward Sawyer, of New York City, County, and State,
United States of America.]
This Invention relates to that class of electric lamps in which light is produced
by the incandesence of a solid conductor, notably of a carbon pencil interposed
between two large carbon electrodes, and constituting a part of the electric circuit.
The general principles upon which such lamps are constructed and operated are
sufficiently understood to render a description unnecessary.
Experience has shown that the carbon pencils employed in lamps of this descrip-
tion after a time cease to maintain a perfect contact or connection with their
carbon holders. The result is the development of the voltaic arc, and because of
the consequent instantaneous shortening of the carbon pencils by disintegration
the lamps must be taken apart, new pencils substituted, and the sealing globe refilled
with a carbon preservative atmosphere.
Experience has further shown that this shortening of the carbon pencil occurs
usually at its contact with the upper holder, probably on account of the con-
centration of heat at that point, and that the shortening is limited in extent to
about one thirty second of an inch. In the poorest lamps of the incandescent
order the life of a pencil of carbon, prior to the occurrence of the voltaic arc, is
about five hours; in the best lamp the life of the pencil is in excess of two
hundred hours. In some a life of probably one thousand hours will be attained,
CD C

page_text: and it is barely possible that in some lamps the arc may never occur, but practically
the manufacture of electric lamps for lighting by incandesence, unprovided with
a remedy for such destructive changes, is so uncertain as to greatly impair the
chances of a general introduction of electric lighting.
In this Invention this evil is directly aimed at, and corrected, wherever the
voltaic are occurs, by at once establishing new points of contact. In the sealed
globe there is placed a long pencil of carbon, which is fed up from the outside
magnetically when necessary, and a lamp equipped with a pencil seven inches long
will be equivalent to at least two hundred and twenty four of the ordinary lamps,
that being the number of times that new points of contact may be established..
Hence it is estimated that as the poorest of the.ordinary lamps will run for five
hours without the occurrence of the voltaic arc, an equally poor feeder lamp pro-
vided with a pencil of carbon seven inches long will run for eleven hundred and
twenty hours before renewal of the pencil will be necessary, or
rsay three hours a
day for a year; and the best lamps will have theoretically a life of forty four
thousand eight hundred hours, or forty years with an average of three hours per
day.
The lamp has a glass globe provided with a rim and a glass stopper ground to
fit same, also a metal flange supported on the rim by any cushioning inaterial.
A wooden. flange or cushion is provided, which supports the metal flange on the
glass stopper. The flanges are beld and drawn together by screws, and the stopper
is thus clamped to the globe. Within the globe there is a copper diaphragm into
which are let three coiled springs, which keep the diaphragm from jamming against
the glass and at the same time hold it firmly in-position. Passing through the
diaphragm and secured by nuts is a long coiled copper tube, the lower end of which
is brazed into an offset but which is drawn to the stopper by a tubular bolt in
which there is a stop cock. In charging the globe with a carbon preservative.
atmosphere the gas enters the tubular bolt and passes upwards through the offset
nut and coiled tube to the top of the globe, thus displacing the air which finds its
exit by way of the opening and stop cock of the tubular bolt.
Passing through the diaphragm and insulated from the same by mica washers
is a standard, whose bent arm carries a grooved carbon roller which is pivotted.
There is also pivotted in the bent arm a second bent arm, which carries a second
grooved pivotted carbon roller. The standard is clamped to the diaphragm by a
nut on the bolt extension of the standard, the offset piece under the nut serving as
a connection with a long coiled solid conductor, the lower end of which screws into
a brass offset, which serves both as the framework for a part of the feeding
mechanism and as a nut for the tubular bolt. Fixed to the coiled conductor is an
arm, to which is attached an adjusting screw and nut by means of which the
tension of a spiral spring connecting with a bent arm is regulated so as to bring
the two carbon rollers together with requisite pressure, a glass link insulating the
arm from the bent arm by means of a spring. Screwing into and through the
-diaphragm-on-a-line -with-the groove-in-the carbon-rollers is a slotted-tube in which-
travels a plunger, to the offset of which is attached a fine steel wire, which passes
upwards over a pulley which is pivotted, and thence downwards over an insulating
wooden drum on the shaft which rotates in the standards of the offset.
Surrounding the end of the tube which projects above the diaphragm is a carbon
piece cut away. Pivotted in the diaphragm is a bent arm to which is fastened by
means of screws a carbon piece. At the lower end of the tube is an arm to which
is attached an adjusting screw and nut, by means of which the tension of the spiral
spring in connection with the bent arm is regulated so as to bring the carbon jaws
together with the requisite pressure.. Enclosed in the tube and passing between
the carbon jaws and the carbon rollers is a long, pencil of carbon, by the incan-
desence of which, in that section which is between the jaws and the rollers, the light
is produced, and by the rotation of a drum this pencil of carbon is fed upwards as
frequently as may be desired, the rollers turning slightly to allow for expansion
and contraction of the pencil when heated and cooled.

page_text: Through the stopper passes another bolt secured by a nut, and in the upper end
of this bolt is pivoted a bent arm to which is fixed a silver plated iron disk, so as
to bring the same directly over the end of a tube bolt. The tube bolt is, of soft
iron, and is wound with insulated wire so as to constitute an electro magnet. The
armature is nomillay kept away from the electro magnet by a spiral spring, which
is held in place by a pin in the bent arm. The range of its movement is limited on
the one hand by its coming in contact with the pole of the magnet, and on the
other hand by the shape of that portion of the bent arm which plays in the bolt
head. Pivoted in the bent arm there is a pawl which engages in the teeth of a
ratchet wheel on a shaft. This pawl is held to its bearing by a spring screwed to
the bent arm; thus at every vibration of the armature the pawl moves the ratchet
wheel one tooth, and thereby winds a wire upon the drum and feeds the carbon
pencil upward. The ratchet wheel is locked against back action by a pawl.
The several joints of the lamp are made air tight by means of cement or wax,
or by other well known means of hermetically sealing.
-
The entire base of the lamp is enclosed in a spun metal cap provided with a
threaded opening, by means of which it is screwed to any fixture. The current
coming from the + point is conducted through the insulating piece to the magnet,
and passes thence by way of one conductor, the carbon pencil, and the other con-
ductor to a bolt, and thence to the spun metal cup through the fixture or standard
through another electro magnet and outward to the point. The armature
of this other electro magnet is thus drawn away from its stop against the force of
a spiral spring let into one of the poles of the magnet. Connected with the
armature outside of the lamp is the conductor leading to the lamp magnet. When
the magnet outside of the lamp is not energised its armature forced upward by its
spring makes connection with the contact piece of a pivoted lever, which is
normally forced against the same stop as the armature by a spring. The electric
current passes from the + point around the lamp to the armature, and the lever
and outward at the point. When the circuit of the carbon pencil is broken
the armature is released and the above circuit established, thus preventing inter-
ruption of the light of other lamps in the circuit. One end of the helix of the lamp
magnet is connected with the magnet, the other end passes through the insulating
piece in the spun cup, and thence to a crank provided with a cam pivoted on a pin.
To energise the lamp magnet and feed up the carbon pencil the crank is turned,
and the crank causes the cam to come in contact with the pivoted lever and
raises the latter from its connection with the armature of the second or outside.
magnet, and instead of the current flowing from the + point to the armature and
the lever, and thence outward at the point it flows by way of the helix of the
lamp magnet to the cam and thence through the lever outward, thus energising
the lamp magnet and moving the ratchet wheel which feeds the carbon pencil one
tooth, and so on, until the circuit of the carbon pencil is re established, when the
armature is again attached and the lamp again operates.
In describing this lamp it has not been considered necessary to describe its
combination with a switch for graduating the light or to indicate the many changes
that may be made in the feeding switch, such as rendering its action automatic by
means of an electro-magnetic vibrator, or of a circuit breaker operated in any
manner and controlled by a magnet. If desired the feeding switch may be
combined in the base of the lamp, and there may be two magnets, one so long as
the circuit of the pencil of carbon exists operating to open the circuit of the other
or feeding magnet, and when the circuit of the carbon pencil no longer exists.
operating to permit the feeding magnet to vibrate its armature until the circuit of
the pencil is re established.

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
3rd March 1880.
FREDERICK JOHN CHEESBROUGH, of the Office for Patents, 15, Water Street,
Liverpool, in the County of Lancaster, Consulting Engineer. "IMPROVEMENTS IN
AND RELATING TO ELECTRIC LAMPS AND SWITCHES. THEREFOR." A communication
from abroad by William Edward Sawyer, of New York City, County, and State,
United States of America.
This Invention relates to that class of electric lamps in which light is produced
by the incandescence of a solid conductor, notably of a carbon pencil interposed
between two large carbon electrodes, and constituting a part of the electric circuit.
The general principles upon which such lamps are constructed and operated are
sufficiently well understood to render a detailed description here unnecessary,
Experience has shown that the carbon pencils employed in lamps of this
description after a time cease to maintain a perfect contact or connection with
their carbon holders. The result is the developement of the voltaic arc, and
because of the consequent instantaneous shortening of the carbon pencils by dis-
integration, the lamps be taken apart, new pencils substituted, and the sealing globe
refilled with a carbon preservative atmosphere.
Experience has further shown that this shortening of the carbon pencil occurs
usually at its contact with the upper holder, probably on account of the concen-
tration of heat at that point, and that the shortening is limited in extent to about
1/32 of an inch. In the poorest lamps of the incandescent order the life of a pencil
of carbon, prior to the occurrence of the voltaic arc, is about five hours; in the best
lamps the life of a pencil is in excess of two hundred hours. In some a life of
probably a thousand hours will be attained, and it is barely possible that in some
lamps the arc may never occur, but practically the manufacture of electric lamps for
lighting by incandescence unprovided with a remedy for such destructive changes
is so uncertain as to greatly impair the chances of a general introduction of electric
lighting.
This present Invention aims directly at this evil, correcting it, whenever the
voltaic are occurs, by at once establishing new points of contact. In the sealed
globe is placed a long pencil of carbon which is fed up from the outside magnetically
when necessary, and a lamp equipped with a pencil seven inches long will be
equivalent to at least two hundred and twenty four of the ordinary lamps, that
being the number of times that new points of contact may be established. Hence,
it is estimated that as the poorest of the ordinary lamps will run for five hours
without the occurence of the voltaic arc, an equally poor "feeder" lamp provided
.with a pencil of carbon seven inches long will run for eleven hundred and twenty
hours before renewal of the pencil will be necessary, or say three hours a day for a
year; and the best lamps will have theoretically a life of forty four thousand eight
hundred hours, or forty years with an average use of three hours per day.
In the Drawings accompanying and forming a part of this Specification, Figure 1
is a side view of the lamp; Figure 2, a front view; Figure 3, a top view of the
upper works; Figure 4, a top view of the feeding mechanism, and Figure 5, a view
of the lamp and its feeding switch with their connections. Likė letters indicate
like points in all the Drawings.
Referring to the Drawings, Figures 1, 2, 3, and 4, A is a glass globe provided
with a rim A¹; B is a glass stopper ground to to the same; C is a metal Hange
supported on the rim A¹ by any cushionary material G; D is a wooden flange or
cushion supporting the metal flange. E on stopper B; F, F, are screws by which the
flanges C and E are drawn together to clamp the stopper to the globe.
H is a copper diaphragm into which are let three coiled springs I which keep

page_text: the diaphragm from jarring against the glass, and at the same time hold it firmly in
position.
Passing through the diaphragm and secured by the nuts L and L' is a long coiled
copper tube R, the lower end of which is brazed into offset nut S, which is drawn
to the stopper B by tubular bolt T in which is a stop cock T¹. In charging the
globe with a carbon preservative atmosphere the gas enters the tubular bolt T and
passes upward through the offset nut and coiled tube R to the top of the globe,
thus displacing the air which finds its exit by way of the opening and stop cock
Qof the tubular bolt Q, which will be more fully described hereinafter.
Passing through the diaphragm and insolated from the same by mica washers
K, K, is a standard J whose bent arm g carries a grooved carbon roller h pivoted
at . Pivoted at in the bent arm g is a second bent arm i, which carries a
second grooved carbon roller j pivoted at 7. The standard J is clamped to the
diaphragm by nut N on the bolt extension L of the standard, the offset piece M
under the nut N serving as a connection with the long coiled solid conductor O,
the lower end of which screws into the brass offset P which serves both as the
framework for a part of the feeding mechanism, and as a nut for the tubular bolt Q.
Fixed to the coiled conductor O is an arm to which is attached the adjusting
screw and nut m, m', by means of which the tension of spiral spring n connecting
with bent arm i is regulated so as to bring the two carbon rollers j, h, together
with the requisite pressure, the glass link o insulating the arm from the bent
arm i by way of spring n. Screwing into and through the diaphragm H on a
line with the groove in the carbon rollers j, h, is a slotted tube bin which travels
a plunger a¹, to the offset a of which is attached a fine steel wire Y which passes
upward over pulley Z pivoted in Z', and thence downward over insulating wooden
druin W on shaft W' which rotates in standards P¹, P', of offset P.
Surrounding the end of the tube b which projects above the diaphragm is a carbon
piece fcut away as shown. Pivoted in the diaphragm at el is a bent arm a to
which is fastened carbon piece f' by screw f Fixed to the lower end of the tube b
is an arm c to which is attached the adjusting screw and nut d¹, d³, by means of
which the tension of spiral spring d connecting with bent arm e is regulated, so as
to bring the carbon jaws f, f¹, together with the requisite pressure. Enclosed in
the tube b and passing between the carbon jaws f, f', and the carbon rollers j, h, is
the long pencil of carbon k, by the incandescence of which, in that section which is
between the jaws and the rollers, the light is produced; and by the rotation of the
drum We this pencil of carbon is fed upwards as frequently as may be desired, the
rollers j, h, turning slightly to allow for expansion and contraction of the pencil
when heated and cooled.
Through the stopper B passes a third bolt U secured by nut L, and in the
upper end of this bolt at U is pivoted a bent arm V to which is fixed a silver
plated iron disk V³, so as to bring the same directly over the end of tube bolt Q.
The tube bolt Q is of soft iron, and being wound with insulated wire Q³ con-
stitutes an electro magnet, one of the poles of which appears at Q².
The armature V³ is nominally away from the magnet by spiral spring V³,
which is held in place by pin V₁ in bent arm V, the range of its movement being
limited on the one hand by its coming in contact with the pole of the magnet Q2,
and on the other by the shape of that portion of the bent arm V which plays in bolt
head U. Pivoted in bent arm V at the point V³ is a pawl Ve, which engages in
the teeth of ratchet wheel W on shaft W1, and this pawl is held to its bearing
by spring V screwed to the bent arm.
.
Thus at every vibration of the armature V³ the pawl Ve moves the ratchet wheel
one tooth, and thereby winds the wire Y upon the drum W, and feeds the carbon
pencil upward, as will readily be understood without further explanation. The
pawl ✗, actuated by spiral spring ✗' from standard P, simply locks the ratchet
wheel against back action as the pawl Ve causes it to rotate.
The several joints of the lamp are made air tight by means of cement or wax, or
by any other well known means of hermetical sealing.

page_text: Referring now to Figure 5, in which the connections of the lamp with its feeding
switch are shown, P¹ is a spun metal cup enclosing the entire base of the lamp, and
provided with a threaded opening by means of which it is screwed to any fixture S.
The current coming from + point is conducted through the insulating piece q to the
magnet Q and passes thence by way of conductor O, the carbon pencil K, and the
conductor R to the bolt T, thence to the spun metal cup, standard S, and the coils
of electro, magnet U outward to the point. The armaturer of magnet U
pivoted at is thus drawn away from the stop x against the force of spiral spring
U let into one of the poles of the magnet. Connected with the armaturer outside
of the lamp is the conductor leading to magnet Q.
When the magnet U is not energised, its armature ? forced upward by spring U₁
makes connection with the contact piece W of lever W, which is pivoted at W' and
normally forced against stop by spring w³, and in that relation the current passes
from the point around the lamp to armature ?, lever W, and outward at the
point. When the circuit of the carbon pencil k is broken the armaturer is released
and the above circuit established, thus preventing interruption of the light in
other lamps in circuit.
One end of the helix of magnet Q is connected with the magnet, as shown; the
other end passes through insulating piece in spun cup P, and thence to crank z,
proveded with a cam Y on pin Y¹. To energize the magnet Q and feed up the
carbon pencil the crank z is turned, and the cam Y coming in contact with lever w
raises the latter from its connection with armature r, and instead of the current
flowing from the + point to armature r, lever w, and outward at the - point, it
flows by way of the helix of magnet Q to cain Y and lever w outward, thus ener-
gising magnet and moving the ratchet wheel, which feeds the carbon pencil one
tooth, and so on, until the circuit of the carbon pencil is reestablished, when arma-
ture is again attached, and the lamp once more operates.
In describing the lamp of this present Invention it is not considered it necessary
to show its combination with a switch for graduating tho light, or to indicate the
many changes that may be made in the feeding switch, such as rendering-its action
automatic by means of an electro magnetic vibrator or of a circuit breaker operated
in any manner and controlled by a magnet. If desired, the feeding switch may be
combined in the base of the lamp, and there may be two magnets, one, so long as
the circuit of the pencil of carbon exists, operating to open the circuit of the other
or feeding magnet, and when the circuit of the carbon pencil no longer exists,
operating to permit the feeding magnet to vibrate its armature until the circuit of
the pencil is re-established.
Having thus fully described this Invention, what is claimed is,―
First. For the purpose of avoiding the formation of the voltaic arc in a sealed
electric lamp, the feeding mechanism, constructed in substance as described, in com-
bination with said. lamp for the purpose of mechanically feeding automatically the
incandescent carbon pencil and maintaining its contact against the carbon rollers
h, j, or other device for diffusing the current and continuing the circuit.
Second. For the purpose aforesaid, in a sealed electric lamp, ajfeeding mechanism,
constructed substantially as described, in combination with an electro magnet or
motor for the purpose of feeding and maintaining electrically the incandescent
carbon pencil against the carbon rollers h, j, or other device for diffusing the current
and continuing the circuit.
Third. In an electric lamp the especial combinations,―
Firstly. Of the diaphragm H, tube b, hinged piece e, and jaws f, f'.
Secondly. Of the diaphragm H, tube b, hinged piece e, jaws ff, and spring d.
Thirdly. Of the diaphragm H, the tube b, and the two carbon holders h and j.
Fourthly. Of the diaphragm H, the two carbon holders f¹ and j, free to move
laterally, and the two.carbon holders f and h, prevented from moving laterally.
Fifthly. Of the two holders fl and j, free to move laterally, and the two holders f
and h, prevented from moving laterally.

page_text: Fourth. In an electric lamp in which light is produced by the incandescence of a
carbon piece, rod, or pencil, the special combinations,-
Firstly. Of the carbon holding tube b, the jaws f, f, the carbon piece, rod, or
pencil, the follower or plunger a', the flexible wire Y, the pulley Z, and the drum
W³, constructed and operating substantially as shown and described.
Secondly. Of the standard J, the rigid carbon holder g, and the jointed carbon
holder i.
4
Thirdly. Of the carbon holding tube b, the upper and lower contact jaws f, f¹, and
h, j, and an electric apparatus operating to feed the incandescent carbon piece, rod,
or pencil to a new contact when required or desired.
Fourthly. Of the tubular conductor R, the offset nut S, and tube bolt T.
Fifthly. Of the bolt Q, offset nut P, standard P', P¹, shaft W¹, and ratchet
wheel W.
Sixthly. Of the magnet Q and bolt U passing through the stopper B of the lamp,
as and for the purpose specified.
Fifth. In an electric lamp in which light is produced by the incandescence of a
carbon piece, rod, or pencil, the combination of the diaphragm H and springs I, as
and for the purpose specified.
Sixth. In the sealed globe of an electric lamp in which light is produced by the
incandescence of a carbon rod, piece, or pencil, electro magnetic apparatus operated
by the direct action of the current to feed such carbon rod, piece, or pencil to a new
contact when required or desired.
Seventh. The feeding switch U, r, W, and Y in combination with the magnet Q.
Eighth. The combination of an electric lamp with the magnet. U, armaturer,
stop X, and lever W, operating substantially as specified.
Ninth. The combination with an electric lamp in which a carbon rod, piece, or
pencil is fed to a new contact when required or desired; of a switch which shifts the
current into and from the coils of an electro magnet by which the feeding mechanism
is actuated without destroying the continuity of the circuit.
In witness whereof, I, the said Frederick John Cheesbrough, have hereunto
set my hand and seal, this Second day of March, in the year of our Lord
One thousand eight hundred and eighty.
FREDERICK JOHN (L.S.) CHEESBROUGH.