IMPROVEMENTS IN ELECTRIC LAMPS OR LIGHTING APPARATUS Communi
Year: 1882

page_text: "
"
LETTERS PATENT to William Robert Lake, of the firm of Haseltine Lake
& C° Patent Agents, Southampton Buildings, London, for an Invention of
IMPROVEMENTS IN ELECTRIC LAMPS OR LIGHTING APPARATUS Communi-
cated to him from abroad by Pierre Tihon and Etienne Rézard both of
Lyons, France.
PROVISIONAL SPECIFICATION left by the said William Robert Lake at the
Office of the Commissioners of Patents on the 15th August 1882.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake and Co., Patent
Agents, Southampton Buildings, London, " IMPROVEMENTS IN ELECTRIC LAMPS
OR LIGHTING APPARATUS [A communication to him from abroad by Pierre Tihon
and Etienne Rézard both of Lyons France]
"
In the electric lamps hitherto constructed, two actions have been made use of to
form the luminous rays, that is to say, that of the voltaic arc, and incandescence.
The latter action is found in all such lamps, without exception, sometimes alone
as in the lamps of Reynier, Werdermann, Maxim, Edison, Lane-Fox, and others;
sometimes combined with the voltaic arc as in all the regulating lamps and electric
candles; but all the lamps or candles belonging to the latter class have been
constructed with the special object of utilizing the voltaic arc.
Now of these two actions (the voltaic arc and incandescence,) the first is
inconstant, irregular and capricious to the last degree, whilst the second, on the
contrary, is steady, regular, and susceptible of taking all the shades which best suit
the sight. But the purely incandescent lamps, hitherto constructed, are under such
conditions that they give a very feeble light in proportion to the resistance which
they introduce into the circuit. With regard to the lamps which utilize the
voltaic arc at the same time as incandescence, such as the regulating lamps, the
latter plays only an insignificant part, viz, the incandescence of the carbon points.
Other lamps utilize it badly, as the Jablochkoff candle, which directs entirely
towards the top the rays emitted by a rod of kaoline, which is moreover much too
small to permit of its storing and retaining for a long time a sufficient quantity of
heat to render it luminous; further the arrangement of this candle, while permitting
37

page_text: the arc to be lengthened in the arc of a circle, removes the latter from the rod of
kaoline, which prevents it from utilizing the conductibility that would give it the
temperature of the arc, so that the latter absolutely left to itself is really the sole
lighting agent of the candle, which renders it very irregular.
Another apparatus (the sun lamp) utilizes well the voltaic arc and incandescence,
but the latter exercising its action always upon the same piece, which is not
sufficiently refractory, changes rapidly the working conditions, and at the same
time causes a change in the quality of the light. This change, however slight,
nevertheless exists and does not fatigue the sight less than the rapid vacillations of
other lamps, and it is an important defect that it is easy to avoid.
According to the said Invention I obviate all these defects by providing a lamp
which, although it is based upon an unique principle, may be varied in form
according to the position which it has to occupy, and according to the duration of
lighting which it is desired the apparatus should have.
In carrying the said Invention into practice I provide upon a disc of marble an
upright of prismatic form in which is placed a rod of refractory material dovetailed
into the latter. This upright is of refractory material and is held by two other
uprights of channel iron connected at their upper ends by a stay insulated
electrically.
In front of this prism are placed two carbon-holders jointed so as to move in two
vertical planes having their point of intersection parallel to the axis of the
refractory prisin and adjacent to the said axis, so that the carbons, by their weight,
are caused to bear against the aforesaid rod, without touching each other; a tongue
or rib slightly projecting from this piece throughout its length, guides the points of
the carbons and maintains them at a constant distance. At the side of each of the
metallic uprights is fixed a vertical rod along which slides a metallic sliding piece
which bears upon the carbons and ensures the progressive descent of their points
along the refractory rod in proportion to the consumption. These sliding pieces
also serve to bring the current into proximity to the points and prevent it from
traversing the whole length of the carbons.
The apparatus operates as follows, that is to say;-The carbons being lighted at
their points by the passage of the current the voltaic arc is established against the
surface of the refractory rod and renders it incandescent.
The object of this incandescence is to facilitate the passage of the current, to fix
the arc in a determined point, and to render absolutely constant the light
emitted; the incandescence of the refractory rod, playing a similar part to the
fly-wheel in a machine, stores the light and distributes it regularly notwithstanding
the intermission in the intensity of the current.

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
15th February 1883.
WILLIAM ROBERT LAKE of the firm of Haseltine Lake & Co Patent
Agents Southampton Buildings London "IMPROVEMENTS IN ELECTRIC-LAMPS OR
LIGHTING APPARATUS A communication to me from abroad by Pierre Tihon
and Etienne Rézard, both of Lyons, France
"
In electric lamps as hitherto constructed, two actions have been made use of for
the purpose of producing light viz, the Voltaic are, and incandescence.
The last named action is found in all lamps without exception, sometimes alono
as in the lamps of Reynier, Werdermann, Maxim, Edison, Lane-Fox and others;
and sometimes in combination with the Voltaic arc as in all the regulating lamps
and electric candles; but all the lamps or candles belonging to the latter class have
been designed with the special object of utilizing the Voltaic-arc.
Now of these two actions, the Voltaic arc and incandescence the first is
inconstant, irregular, and capricious, while the other on the contrary, is steady,
regular, and capable of taking all the shades which best suit the sight.
But purely incandescent lamps, as hitherto constructed, are of such a character,
that in comparison with the resistance they introduce into a circuit, they give but
a very feeble light.
As regards lamps in which the Voltaic-arc in combination with incandescence is
utilized, some of them, like regulating lamps, allow of but a very insignificant part
being played by incandescence, that is, only the points of the carbons are rendered
incandescent. In other lamps it is badly utilized as for instance, in the Jablochkoff
candle which simply directs upwardly the rays emitted by a kaoline rod, which in
any case is too small to be capable of storing up and retaining long enough a
sufficient quantity of heat to render it luminous, further the arrangement of this
candle while permitting the arc to be lengthened out excessively in an arc of a
circle, removes the latter too far away from the kaoline rod, which prevents it
from taking the fullest advantage of the conductibility which the temperature of
the arc would impart to it; so that the arc absolutely left to itself becomes really
the sole lighting agent of the candle which renders it very irregular.
Another apparatus (the Sun lamp) properly utilizes the Voltaic arc and incan-
descence, but inasmuch as the action of incandescence is being constantly exerted
upon the same part which is not sufficiently refractory and speedily alters its
working conditions, the quality of the light changes. These changes which proceed
slowly weary the eye less than the rapid vacillations of other lamps but nevertheless
they constitute a very serious defect.
According to the present invention I obviate all these defects by providing a
lamp which although founded upon an unique principle varies in form according
to the position it is intended to occupy and according to the length of time during
which the apparatus is required to be in action.
In the accompanying drawing
Figure 1 is an elevation of a lamp constructed according to this invention
Figure 2 is a plan of the same
Figures 3, 4 and 5 are elevations illustrating modifications of this invention.
Figures 6, 7, 8 are plans of the same respectively.
Figure 9 is a detail view
Referring to Figures 1 and 2-upon a disc D of marble, wood, or other insulating
material is placed a standard M of prismatic form and composed of fire-clay in
which is fitted a rod T of refractory material by means of a dovetail joint likewise

page_text: composed of refractory material. This standard M is supported by two metallic
standards N N connected at their upper extremity by a cross piece electrically
insulated.
In front of this standard M are placed two carbon-holders P jointed or resting
in cup shaped cavities and moving in two vertical planes, having their point of
intersection parallel to the axis of the refractory prism and adjacent to the said
axis; so that the carbons, by their own weight, are caused to rest against the rod T
without touching one another; a tongue or rib which slightly projects from this
part throughout its entire length, guides the points of the carbons and keeps them
at a proper distance apart. At the side of each of the metallic standards N is
fixed a vertical rod K along which moves a metallic slide C which presses against
the carbons and ensures the progressive descent of their points against the
refractory rod as the consumption proceeds. These slides also serve the purpose
of conveying the electric current to the carbon-points, thus preventing it from
traversing the entire length of the said carbons,
The operation of the lamp is as follows, that is to say-The carbons being lighted
at their points by the passage of the current the Voltaic arc is established against
This state of
the surface of the refractory rod and renders it incandescent.
incandescence facilitates the passage of the current, fixes the are at a given point,
and imparts absolute steadiness to the light emitted, the incandescence of the
refractory rod doing a similar duty to that of a fly-wheel in an engine, accumulating
and distributing the light with regularity notwithstanding the intermissions of
intensity in the generating current.
In the modification of this invention shown in Figures 3 and 6, the insulating
prism of refractory material is dispensed with and the rod T is directly held up by
the metallic standards N' N' which slightly differ in form from those shown in
Figure 1. Only one of these standards is fixed to the base, the other is jointed at a
so as to render it possible to turn it aside for the purpose of facilitating the
insertion or removal of the rod T. It is also fitted with a small device for the
purpose of keeping the said rod at a certain level, and preventing it from dropping
down too low in the holder where it would not be utilized. To this end a piece (+
runs through one of the standards at a suitable distance from the base of the
apparatus; and this piece prevents the rod T from dropping down. The piece G
is connected with a vertical rod placed in the rear of the apparatus and terminating
at its upper extremity in a small handle electrically insulated, but which keeps
linked together the two standards of the lamp. By pulling this small handle the
jointed standard is unhooked, while at the same time the small piece which holds
the incandescent rod moves back and separates the two standards of the lamps.
The incandescent rod thus released slips through an aperture which is purposely
made in the base and drops down beneath the apparatus, where it can be caught in
a box placed there for the purpose.
The construction shown in Figures 4 and 7 differs from the preceding con-
struction in the arrangement of the metallic standards, by which modification it
becomes possible to place several pairs of carbons and several refractory rods side
This
by side to consume automatically one after the other in succession.
arrangement is intended for lighting purposes of long duration. The principal
working part, which is not used in the lamps shown in Figures 1 and 3, is the joint
of the carbon-holders upon which the commutation depends. These carbon-
holders and their supports are furnished with a notch opening into the aperture of
a pin. This pin, which is pressed at one of its ends by a spring-box placed beneath
it, carries a spring key which abuts against a carbon-holder when the latter carries
a carbon not completely consumed; but as the combustion proceeds, the carbon
holder inclines downwards, and at the precise moment when the carbon is consumed
the notch of the carbon holder comes in front of the notch in the support into which
is entering the spring key of the pin. The latter now, not being held back, passes
through the carbon-holder and allows the spring-box to turn away to a certain
extent, and this movement produces the commutation.

page_text: In Figures 5 and 8 the construction is similar to that shown in Figure 4 with
the difference that the carbons and refractory rods, instead of being placed side by
side in the same plane, are arranged around a cylinder. This cylinder may be
placed vertically or horizontally and consists of two insulating discs linked together
by cross pieces, so arranged as to receive the refractory rods, either directly, or
through the medium of the refractory prisms S. To the right of the apparatus are
shown the pieces A A', which hold the carbons C C C". Springs keep the
carbons constantly against the refractory rods until entirely consumed.
The operation of this apparatus is as follows that is to say; the current entering
the lamp through the wires F passes on to the supports of the carbon-holders A
and A' through two contact pieces E each resting against a carbon-holder, it thence
passes to the carbons C and C¹, whence the Voltaic-arc is formed causing the
incandescence of the rod R. When the carbons are consumed, the disc, in the
present instance, will give one eighth of a revolution and as the contact pieces do
not turn, they serve as commutators; the current then flows to the carbons C C
and so on until all the carbons around the cylinder have been consumed.
The commutation is brought about in the following manner, that is to say-Each
carbon-holder X has a small notch, the supports of these carbon-holders also have
small notches of the same character. These notches do not coincide with one
another except when the carbon-holders and their support occupy, in relation to
one another, a position as shown at X' which is the position of the carbon-holders
when the carbons are completely consumed; till then the notches do not become
coincident. A spring-box or a counter-weight tends to keep the lamp continuously
revolving in a given direction; but a small tappet fixed upon the framing of the
lamp is so arranged, as to enter the notches of the supports and of the carbon
holders so long as the carbons are not completely consumed; but when the
consumption is complete, the notches stand in front and the tappet no longer
interferes with the movement and therefore allows the lamp to rotate one eighth
of a revolution, but when the first carbon-holder of the next pair of holders reaches
this tappet, it being furnished with a fresh carbon has not its notch facing that of
the support, and in consequence it will come in contact with the tappet, which will
then arrest the progress of the apparatus. During this operation the preceding
pair of carbons has been taken out of the circuit, and a new pair has come into
connection and this movement continues until the eight pairs of carbons placed
around the cylinder have been consumed. It is obvious that a lamp constructed
according to this modification of my invention may have as many pairs of carbons
as desired.
The process of commutation can be still further simplified by connecting one
half of the carbons to the axis of the apparatus which thus would become one of
the poles of the lamp. In that case there would be only a single frictional
contact piece in connection with the other half of the carbons insulated from one
another.
The lamp and the modifications thereof hereinbefore described are fitted with
igniters arranged and working as shown in Figure 9 viz.
A square rod E is placed parallel to the rods K which guide the slides C. This
revolves upon its own axis carrying with it in this movement a runner or slide C"
Figure 3. This runner is fitted with a blade which carries at its extremity a pair
of forceps between which is gripped, in a vertical position a piece of carbon Y
somewhat thick and a few centimetres in length.
The rod E carries at its foot a small arm a¹ which projects horizontally from it.
A connecting rod jointed a little lower down carries on its upper extremity two
projections a between which is grasped the arm a fixed to the square rod E.
Upon the connecting rod is fixed a bar of soft iron f which serves as an armature
to the bobbin r¹ arranged horizontally. Upon the bar f is also placed a small
bobbin ?, movable longitudinally upon it, and which, while magnetizing the said
armature serves also as a counter-poise in conjunction therewith to keep the
connecting rod in the position 1. In this position which is that which it occupies

page_text: when the lamp is not in action, the bobbin and the soft iron bar fare driven
aside, and the runner or slide C", by means of the blade and the forceps, keeps the
piece of thick carbon against the two carbons of the lamp and thus connects them
at their points.
The slide or runner C¹¹ is movable along the square rod E, but it cannot move
downward except when the slide C¹ itself descends, that is to say, as and when the
carbons consume, in relation to which carbons it always stands on a level with
their points. When the current passes into the lamp it magnetizes the two
bobbins and r', the bar f is attracted, and the connecting rod assumes the
position . In its movement it has carried with it the small arm a¹ fixed to the
foot of the square rod E, and the latter thereby gives about one fourth of a turn.
The piece of carbon Y, till then held in contact with the two carbon rods, is
then driven aside and the arc is formed.
Another arrangement shown in Figures 3 and 6 consists in the fixing to the
bottom of the square rod E a small pinion a³. Engaging with the said pinion is a
rack a carrying at one end a soft iron bar f' which enters freely into a hollow
bobbins, when the current magnetizes this bobbin ; but so soon as the current
ceases to flow, a small spring coiled around the foot of the rod E causes it to revolve,
when it draws the bar f' from within the bobbin and brings the carbon Y into
contact with the two carbons of the lamp.
It is obvious that the light will last a long time without necessitating a renewal
of carbons.
The arrangement shown in Figures 5 and 8 is designed for lighting large areas,
as it admits of the apparatus being placed inside a globe where the light emitted is
thrown from above, downwards (in case the lamp is placed horizontally) without
casting a shadow upon the ground, as the luminous cone has its axis perpendicular
to the ground.
I do not limit myself to the form of refractory rod hereinbefore described and
shown in the drawing, for, if desired, I can substitute therefor a disc or block of any
desired shape against which two or more carbons may bear for the purpose of
obtaining as powerful a light as desired. The arrangement then might be the same
as that adopted in the lamps herein before described, that is say, the carbons would
burn alongside this block which in this case would be prismatic in form.
the disc form, on the contrary, the carbons may be driven against the edges of the
disc and cause it to revolve in proportion to its calcination.
With
The said refractory pencil or rod may be composed of chalk, lime, clay, gypsum,
magnesia or other analogous substance. These substances may be used in a pure
state or in combination one with the other, or other insulating substances, according
to the hues and tints which it is desired to impart to the light. An addition of
powdered coke by making a better conductor of the rod, lessens the resistance and
thereby causes the carbons to consume more slowly.
The standard of fire clay, shown in Figures 1 and 5 is not essential. It merely
serves to secure a more perfect insulation of the carbons and also to protect the
metallic working parts from the heat evolved by the incandescence of the rod.
In contradistinction to Jablochkoff's lamps in which a fusible or vitrifying
substance is employed. I select in preference all substances that will calcine without
melting, because with fusible substances the small liquid drop forming between the
points of the carbons acts as a lens and a reflector, being first convex and then
concave, and changing its form by the effect of ebullition and thus supplies a
continuous source of perturbation in the fixity of the light.
This improved lamp can, if desired, be altered into a lamp purely incandescent
on Regnier's and Wedermann's principle. For that purpose the refractory rod is
substituted by a similar carbon rod. Another small carbon resting upon an
insulated support leans against this carbon rod.
A small runner or slide then
bears against this small carbon and brings the current to it. The said small carbon
then forms one electrode, and the other carbon the other electrode.
Having thus fully described the said Invention as communicated to me by my

page_text: foreign Correspondents, and the manner of performing the same, I wish it under-
stood that I claim
First An electric lamp or lighting apparatus constructed according to either of
the modifications above described.
Second-In an electric lamp or lighting apparatus, the employment, in addition
to the two carbons ordinarily used, of a pencil or rod of refractory material against
which the said two carbons bear, and of such form as to maintain the two
carbons at an uniform distance apart during their consumption, substantially as
described.
In witness whereof I the said William Robert. Lake have hereunto set my
hand and seal this Fifteenth day of February in the year of our Lord One
thousand eight hundred and eighty three.
W ROBT LAKE (L.S.)