IMPROVEMENTS IN APPARATUS FOR ELECTRIC LIGHTING
Year: 1879

page_text: LETTERS PATENT to Richard Werdermann, of Princes Street, in the County of
Surrey, Civil Engineer, for the Invention of "IMPROVEMENTS IN APPARATUS
FOR ELECTRIC LIGHTING."
Sealed the 5th December 1879, and dated the 10th June 1879.
PROVISIONAL SPECIFICATION left by the said Richard Werdermann at the
Office of the Commissioners of Patents on the 10th June 1879.
RICHARD WERDERMANN, of Princes Street, in the County of Surrey, Civil
Engineer. "IMPROVEMENTS IN APPARATUS FOR ELECTRIC LIGHTING."
My Invention relates chiefly to further improvements in parts of the apparatus
described in the Specification of Letters Patent granted to me the 21st June 1878,
No. 2477, and has for its principal object to provide improved means for constantly
keeping the two electrodes in the proper relative position with regard to each other
whatever may be the irregularity in the consumption of the vertical electrode or
carbon rod as the light is being developed; also to provide means whereby the
carbons or electrodes in any lamp in a circuit will be automatically cut out of or
detached from the circuit whenever the carbon rod is entirely or nearly consumed,
so that when this occurs in any one or more of the lamps the other lamps will not
be in any way affected thereby.
In carrying this Invention into practice the upper or larger electrode is secured
as heretofore by means of a clamp, but instead of attaching the said clamp to the
fixed vertical rod or bar in the manner described in the said former Specification I
connect to the clamp an arm, which is placed in a horizontal position, and is pivoted
to a sliding piece on the said fixed vertical bar in such a manner that it can move
upon this pivot as its centre, and therefore the larger or upper electrode, with the
said horizontal arm, may rise and fall, describing a portion of a circle in its move-
ment. The said horizontal arm is carried beyond the vertical rod, and is provided
with a screw thread upon a portion of its length, a nut being placed upon this
screwed portion to serve as a balance to the larger electrode. By means of this nut
the said electrode may be balanced as desired, and the nut is to be so adjusted that
this electrode will just overbalance it, and descend when not in contact with the
point of the smaller or vertical electrode or carbon rod, and as the latter is con-
sumed the larger electrode assists by its gravity in maintaining the proper connection
[Price 6d.1
.
'

page_text: with the smaller one; the latter is fitted to slide through guides, as described in my
said former Specification; but instead of employing the annular spring or elastic
ring encircling the guides the two portions of the latter are fitted together so as to
exert a sufficient normal pressure upon the carbon rod, and any desired increase of
pressure that may be necessary to prevent the carbon rod from travelling too rapidly
is applied automatically and with great exactitude, according to the requirements
under all circumstances by means of the following devices, that is to say :-A flat
spring or spring-bar is placed vertically near the said guides, and in the upper part
of this spring there is a screw with a milled head, the latter being provided to
facilitate the adjustment of the screw as required. The point of the screw extends
through the spring nearly to the surface of the guide. The said vertical spring or
spring-bar is attached at its lower end to the short vertical arm of a two-armed
lever, which is pivoted to a lug or ear on the standard or pillar; the other arm of
this lever extends in a horizontal direction, and is bifurcated at its extremity to
enclose a moveable vertical rod connected at its upper end to the aforesaid horizontal
arm to which the larger electrode is attached. There is a screw-nut with two milled
flanges or rims on the said movable vertical rod at the part where the bifurcated
arm encloses this rod, and the said arm passes between the two flanges; this nut
provides for any required adjustment of the two-armed lever, and consequently of
the vertical spring attached thereto. From the above description it will be seen
that the said movable vertical rod being connected to the horizontal arm carrying
the larger electrode moves with it, and that any notion imparted to this rod will
be communicated through the two-armed lever to the vertical spring and the screw
in the upper part of the same. Should the carbon rod be rising too rapidly by
reason of insufficient pressure on the guides the larger or upper electrode will be
pushed upward thereby, consequently the said movable vertical rod will also rise,
carrying with it the bifurcated arm of the two-armed lever, and the point of the
screw in the upper part of the spring will be pressed against the surface of the guide
with a pressure in proportion to the distance which the upper or larger electrode
has been elevated; the movement of the carbon rod will thereby be immediately
checked, and its proper rate of speed will be ensured. As the upper carbon descends
to its normal position the movable vertical rod also descends, and the pressure of
the screw on the guide is thereby relaxed, and thus the speed of the carbon rod is
continuously and automatically regulated, the said regulating devices accurately
compensating for any excess of weight.
When the carbon rod is entirely or nearly consumed the upper or larger carbon will
have fallen to or nearly to the points of the guides, and the said movable vertical
rod will also have descended a proportionate distance. I so arrange the length of
this rod that when this occurs its lower end will come into contact with a screw in
an arm extending from the standard or pillar, and the electric current will there-
fore be provided with a short circuit, that is to say, it will not travel through the
carbons but through the bifurcated arm of the two-armed lever to the vertical rod;
thence through the screw with which the end of this rod is in contact, and thus to
the line-wire out of the lamp. Some portion of the said vertical rod must be
insulated. The carbons in this particular lamp will thus be cut out of or detached
from the circuit automatically, and the other lamps in the circuit will not be
affected.
I may modify the devices for obtaining the above named results as follows, that is
to say-The two electrodes will be arranged as above described, but instead of the
movable vertical rod, vertical spring or spring-bar, and two-armed lever, I attach to
the horizontal pivoted arm carrying the larger or upper electrode a flat spring so
bent that its lower end extends to within a short distance of the surface of the
guide, and at this part of the latter I provide a piece of some insulating material.
The lower end of this bent spring therefore answers the same purpose as the screw
in the end of the vertical spring hereinbefore described. If the carbon rod rises too
rapidly, and raises the upper or larger electrode, the bent spring also rises, and its
lower end presses against the guide, and retards the movement of the carbon rod, as

page_text: herein before described; the falling of the upper electrode relaxes the pressure. This
bent spring also serves to provide a short circuit for the current, a bent arm being
attached to the lower part of the guides, and extending upward to such a position
that the lower end of the said bent spring comes in contact therewith when the
upper or larger carbon has descended far enough, that is to say, when the carbon
rod has been entirely or nearly consumed.
I may also regulate the speed of the carbon rod as follows, that is to say:—I
provide a space or opening in the lower part of the guides, and through this space a
bar passes, carrying two friction-rollers arranged to press against the carbon rod at
this portion thereof. One end of this bar is connected to the lower end of a vertical
rod whose upper end is attached to the aforesaid horizontal arm which is connected
with the upper or larger carbon. The said vertical rod therefore moves with this
horizontal arm. To the other end of the said roller-bar a spiral spring is attached,
the latter being connected to a short rod provided with a nut by which it may be
adjusted vertically; this rod is screwed into the inetal at the upper part of the
standard or pillar. The bar carrying the rollers is pivotted to a lug or ear on the
outside of the guide. The tension of the spiral spring is adjusted so that the
pressure of the rollers on the carbon rod is what will be required under ordinary
circumstances, but should the said carbon rod rise too rapidly the vertical rod
attached to the horizontal arm in connection with the upper or larger electrode will
rise with the said electrode, and cause the rollers to exert greater pressure on the
carbon rod, and so retard it. The speed having been so checked the upper electrode
descends again, and with it the vertical rod, and the pressure of the rollers is thus
relaxed. In this arrangement the annular spring or elastic ring described in my
said former Specification will be employed to clamp the guides but will not require
readjustment during the time the light is being developed as the said friction-rollers
provide for any irregularity that may occur.
Another part of my present Invention relates to means for introducing the carbon
rod into the lamp at the lower part of the same instead of at the upper part thereof
as heretofore. For this purpose I make the tube enclosing the carbon rod several
inches longer than heretofore, and the piston or piece which is operated by the
weight to push the carbon rod upward has attached to its lower end a cord, which
is wound around a small pulley or roller fixed in the lower part of the tube. The
latter is open at the bottom, and there is also an opening on one side near the lower
end of the tube. When it is desired to insert a fresh carbon rod the small pulley or
roller is turned so as to pull the piston or sliding piece down to one side of the tube,
then the carbon rod is inserted at the bottom and pushed beyond the piston, where-
upon the latter is readjusted underneath the rod, and is ready to operate under the
action of the weight.
A further improvement relates to means for diffusing or reflecting the light, and
for this purpose I place at a convenient position under the light an opal dish,
through which some of the light passes downward in direct tangential rays. From
this dish a portion of the light is reflected upward upon a broad deflector of card,
porcelain, or any suitable material, either white or of any desired colour, fixed above
the electrodes, and the light is thus deflected downward. I find that by this
arrangement no dark shadows are thrown in any direction.
The upper electrode may in all cases, if desired, be made of copper or other suit
metal instead of carbon, and my said improvements may be used whether the light
is developed or emitted by means of a voltaic arc or by the incandescence of the
carbon.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Richard Werdermann in the Great Seal Patent Office on the 10th
December 1879.
RICHARD WERDERMANN, of Princes Street, in the County of Surrey, Civil
Engineer. "IMPROVEMENTS IN APPARATUS FOR ELECTRIC-LIGHTING."
My Invention relates chiefly to further improvements in parts of the apparatus
described in the Specification of Letters Patent granted to me the 21st June
1878, No. 2477, and has for its principal object to provide improved means for con-
stantly keeping the two electrodes in the proper relative position with regard to
each other, whatever may be the irregularity in the consumption of the vertical
electrode or carbon rod during the development of the light. It has for its further
object to provide means whereby the carbons or electrodes in any lamp in a circuit
will be automatically cut out of or detached from the said circuit whenever the
carbon rod of tho said lamp is entirely or nearly consumed, so that when any one
or more of the lamps in the circuit is in this condition the other lamps will not be
in any way affected thereby.
In an electric lamp or lighting apparatus wherein the light is devoloped between
two carbons, as in my said former Specification, the uniformity of the light depends
in a great measure upon the maintenance of an exact proportion between the rate
of combustion of the smaller electrode and the rate of its movement toward the
larger electrode. To ensure this result I provide my improved lamp with means
whereby any excess or deficiency in the rate of movement of the smaller-electrode
or carbon pencil will cause the larger electrode or carbon disc to move and adjust
devices, which immediately counteract such excess or deficiency.
My improvements may be embodied in various forms or modifications, some of
which I have shewn in the accompanying Drawing.
One form of my apparatus is shewn in Figure 1, which is a side elevation of the
sanie. In this apparatus the upper or larger electrode a is secured as heretofore by
means of a clamp b, but instead of attaching the said clamp to the fixed vertical
rod or bar c in the manner described in the said former Specification I provide the
clamp b with an arm b', which is pivotted to a piece & fitted to slide on the said
fixed vertical bar. The said arm is arranged in such a manner that it can move upon
this pivot as its centre, and therefore the larger or upper electrode a with the said
arm b¹ is capable of adjustment toward and away from the lower electrode or
carbon pencil e. The said arm b¹ extends beyond its pivot on the vertical rod c,
and is screw-threaded upon a portion of its length and provided with a nut ƒ on
this screwed portion, the said nut being sufficiently heavy to counterbalance the
electrode or disc a. The said nut is to be so adjusted that the weight of the
electrode will slightly preponderate over that of the nut, in order that the electrode
may descend when not in contact with the point of the smaller or vertical electrode
or carbon rod e; and as the latter is consumed the larger electrode assists by its
gravity in maintaining its proper connection with the smaller electrode or carbon
pencil c. The latter is fitted to slide through guides g, as described in my said
former Specification, but instead of employing the annular spring or elastic ring
encircling the guides the two portions g¹, y, of the latter are fitted together by
pivotting one to the other at y*, or otherwise so connecting them that one or both
will be capable of adjustment. In commencing to work, these guides are adjusted
as nearly as practicable to exert the required pressure upon the carbon rod to
ensure its moving upward at the proper rate of speed by the action of the springs,
weights, or other means used for this purpose.
But this upward movement cannot be advantageously maintained at one uniform

page_text: rate, because of the variations which occur in the rate of combustion of the carbon.
I therefore provide for varying this rate of movement in proportion to the varia-
tions in the rate of combustion by increasing or decreasing the lateral pressure on
the said carbon rod to prevent its travelling too slowly or too rapidly. This
variation of pressure is obtained automatically and with great exactitude according
to the requirements of the lamp under all circumstances by the following devices;
that is to say, a flat spring or spring bar h is placed near the said guides, and has
in its upper part a screw h¹, preferably provided with a milled head to facilitate its
manipulation, so that the point of the screw which extends through the spring
to the surface of the guide may be set or adjusted as required. The said spring
or spring-bar is attached at its lower end to the short arm h² of a two-armed lever,
which is pivotted to a lug or ear on the standard or pillar i. The other arm ³ of
this lover is bifurcated at its extremity to fit a doubly collared or flanged nut ; on a
vertical rod j connected at its upper end to the aforesaid arm b', which carries the
larger electrode a. The aforesaid doubly flanged screw-nut has its flanges or collars
milled to facilitate its manipulation. This nut provides for any required adjust-
ment of the two-armed lever, and consequently of the vertical spring attached
thereto. From the above description it will be seen that the said vertical rod j'
being connected to the arm b¹ carrying the larger electrode moves with it, and that
any motion imparted to this rod will be communicated through the two-armed
lever, h³, to the spring and the screw h'. Should the carbon rod or pencil e be
rising too rapidly by reason of insufficient pressure on the guides, the larger or
upper electrode a will be thereby pushed upward; consequently the vertical rod j¹
will also rise, carrying with it the bifurcated arm h³ of the two-armed lever, the
point of the screw h¹ in the upper end of the spring / being then pressed against
the guide g², and the pressure or friction of the latter on the carbon rode boing
increased the upward movement of the carbon rode will thereby be immediately
checked or retarded, so that it is no longer too rapid for the rate of combustion
of the carbon, and the upper carbon a will then descend to its normal position.
As it descends the vertical rod j' also descends, and the pressure of the screw h' on
the guide g² is relaxed, so that the speed of the carbon rod may be again accel-
erated if not quick enough. Thus the speed of the carbon rod is continuously
and automatically regulated, and there will be no variation or irregularity of the
light by reason of variations in the rate of combustion, or excess or diminution of
weight of the carbon.
It will be obvious that the variations in the movement of the rod e and of the
disc a and parts connected therewith will be very slight, as in commencing to move,
the said disc immediately imparts a compensating or counteracting movement to
the checking devices. And as the said regulating or checking devices are exceed-
ingly delicate or sensitive, they will be subject during the development of the
light to a succossion of minute and imperceptible oscillations which will not perinit
the slightest perceptible variations in the emission of light.
When the carbon rod e is entirely or nearly consumed, the upper or larger carbon
a will have fallen to or nearly to the top of the guides, and the said vertical rod ¹
will also have descended a proportionate distance, and the screw h' is moved away
from the guide as shewn in dotted lines. I so arrange the length of this rod 11, that
when this descent occurs, its lower end will come into contact with a screw k in an
arm extending from the standard or pillar i. The lower portion of the rod j' is in-
sulated from the upper portion by the introduction of any suitable insulating
material at j, the electric current will therefore be provided with a short circuit,
that is to say, it will not travel from the wire or conductor 1 through the carbons,
but through the bifurcated arm h of the two-armed lever to the vertical rod 1¹,
thence through the screw k with which the end of this rod is in contact, and thence
to the line wire out of the lamp; the carbons in this particular lamp will thus
automatically be cut out of or detached from the main circuit, and the other lamps
in the circuit will not be affected.

page_text: I may modify the devices for obtaining the above named results as shewn in side
elevation in Figure 2. In this modification of my Invention, the two electrodes a,
e, are arranged as above described, but instead of using a regulating device con-
sisting of the vertical rod and spring or spring-bar and two-armed lever, I attach to
the pivotted arm b², carrying the larger or upper electrode a, a, spring so formed
that its lower end extends to or nearly to the surface of the guide g², and at this
part of the latter I provide a piece of some insulating material as shewn at g°.
The lower end of this spring therefore serves the same purpose as the screw h¹ in
the end of the spring h hereinbefore described. If the carbon rod or electrode e
rises too rapidly and raises the upper or larger electrode a, the spring 7 also rises,
and its lower end presses against the guide, and retards the movement of the carbon
rode and the falling of the upper clectrode relaxes the pressure, as and with the
effect above described. This bent spring also serves to "short circuit" the current
as follows, that is to say:--An arm m is attached to the lower part of the guides g,
and extends upward to such a position, that when the carbon or electrode e is
nearly consumed, and the upper carbon or disc a has descended, the lower end of
the said spring comes in contact with the arm or piece m, thereby forming a short
circuit through the arm m, spring l, arm b², and pillar c.
し
In Figure 3 I have shewn in side elevation a further modification of the above
described apparatus. In this modification the carbon disc or electrode a is carried
by the arm b, which is pivotted at 6 to the vertical rod or bracket c. The latter
is formed of ebonite or other suitable insulating material, or if made of metal, is
insulated in any convenient manner. At 63, this arm b¹ has jointed to it a rod or
link n, whose lower end is jointed to the long arm o of a two armed lever which is
rigidly attached at its fulcrum o', to the adjustable part g² of the guide, so that this
part of the guide is movable with the said lever. Consequently, when the disc a is
raised by reason of the too rapid upward movement of the carbon rod e, and thereby
through the link n, depresses the arm o of the said lever, the upper extremity of
the part of the guide is forced inward, and thus the lateral pressure upon the
carbon rod e will be increased. Then the upward movement of the carbon rod e
will be retarded, until the disc a descends and relaxes the lateral pressure of the
guide on the rod e; the compensating action thus obtained will, as above described,
prevent any perceptible variation or fluctuation of the light, as in the apparatus
above described.
When the carbon rod e is nearly consumed, the lamp is "short circuited" as
follows: The descent of the disc a and its arm 61 causes the rod n and arm o of
the two-armed lever to rise; consequently, the short arm of of the said lever has its
adjustable screw or stud os brought into contact with the plate or piece p with
which the conducting wire 2 is connected; the current then passes from point o¹
through the arm o² of the said lever, and through the stud os and piece p, to the
wire 2.
Another modification of the said apparatus is illustrated in Figures 4 and 5.
Figure 4 is a sectional side elevation, and Figure 5 is a plan or top view. In this
instance, the clamp or ring b which carries the carbon disc a is supported excen-
trically on pivots or pintles 6 fitted in a fixed horizontal arm extending from the
rod or bar c. The excentricity of the carbon disc is such that its weight prepon-
derates on the side with which it is in contact with the carbon rod e. The spring
in this case is fixed on the ring or clamp 6 of the disc a, and bears against a piece
of insulating material on the guide g, as in the apparatus shewn in Figure 2. "The
effect of the raising and lowering of the disc a, and the resulting compensating
action of the regulating devices will be the same in this form of my Invention, as
in those above described; and the "short circuiting" devices may be arranged as
in Figure 2, or in any other suitable manner.
Figure 6 shews in sectional elevation another modification of my apparatus in
which the lateral pressure on the carbon rod e, for the purpose above specified is
controlled or regulated by means of two rollers q mounted on a rod or bar q³,

page_text: which is pivotted or fulcrumed at 92, and extends through a space or opening in the
lower part of the guides. One end of this bar is connected to the lower end of a
vertical rod 2, whose upper end is attached to the arm b¹, which is connected with
the upper or larger carbon a. To the other end of the said roller-bar q', a spiral
spring is attached, the latter being connector to a short rod provided with a nut by
which it may be adjusted vertically. The tension of the spiral spring is adjusted
by any suitable means to regulate the pressure of the rollers on the carbon rod.
The rising and falling of the upper electrode or carbon ball a will have the same
compensating effect as in the other forms of my improved apparatus above
described.
I prefer to use means for diffusing or reflecting the light as follows:-For this
purpose I place at a convenient position under the light an opal dish through which
some of the light passes downward in direct tangential rays. From this dish a
portion of the light is reflected upward upon a broad deflector consisting of a
horizontal disc of card board, porcelain, or any other suitable material, either white or
of any desired color, fixed above the electrodes; the light is thus deflected
downward. I find that by this arrangement no dark shadows are thrown in any
direction.
Having thus fully described my said Invention, and the manner of performing
the same, I wish it understood that although the various forms or modifications
shewn in the accompanying Drawing afford examples in which the said Invention
may be very conveniently and advantageously carried into practice, yet I wish it
understood that I do not limit myself to the precise details of construction and
arrangement of the parts shown, as such details may be further varied or modified
without changing or departing froin the principle of my Invention; for example,
the upper electrode may be formed of copper or other suitable material instead of
carbon; the construction of the guides and the means or devices for causing the
movement of the upper electrode to effect the variation of the lateral prossure on
the other electrode, and the arrangement of the "short circuiting" devices are suscep-
tible of various modifications other than those above described, and, if desired, the
lamp may be constructed with the carbon disc or large electrode placed below or in
any other convenient position with regard to the other electrode. Furthermore,
the variation of the rate of movement of the one electrode may be produced by its
pressure on the other electrode otherwise than by varying the lateral pressure.
But all of these different arrangements or modifications of the said apparatus must
embody the essential feature of my Invention, that is to say, the compensating
action whereby the movement of the one electrode towards the other. is maintained
in duc proportion to the combustion of the electrode, and I claim,-
First. In an electric lamp or lighting apparatus wherein the light is produced or
developed between two electrodes, such as those above described, and one of which
continually moves toward the other, the regulation or controlling of the rate of
movement of the same in proportion to its rate of combustion by its pressure on
the other electrode at their point of contact for the purpose specified.
Second. In an electric lamp or lighting apparatus wherein the light is produced
or developed between two electrodes, one of which continually moves toward the
other the regulation or controlling of the lateral pressure upon the said moving
electrode by its pressure on the other electrode at their point of contact, for the
purpose set forth.
Third. The novel construction and arrangement of the parts or devices for
effecting the variation in the lateral pressure on the lower electrode by the vertical
pressure of the latter upon the upper electrode, substantially as described and as
embodied in either of the forms of apparatus illustrated in the accompanying
Drawing.
Fourth. In combination with the other parts of my improved lamp the peculiar
arrangements or devices for forming the short circuit in the same, as shewn in

page_text: either of the forms illustrated in the accompanying Drawing, and for the purpose
specified.
In witness whereof, I, the said Richard Werdermann, have hereunto set my
hand and seal, this Tenth day of December, in the year of our Lord One
thousand eight hundred and seventy-nine.
R. WERDERMANN.
(L.S.)