Improvements in Electric Arc-lamps.
Year: 1897

page_text: Date of Application, 23rd Feb., 1897-Accepted, 1st May, 1897
Improvements in Electric Arc-lamps.
We, HIPPOLYTE DELAVAU, President of the Tribunal of Commerce at
Chatelleraut, in the Department of the Vienne, France, and FRANCOIS FÉLIX
BRERAT, Electrical Engineer, also of Chatelleraut, do hereby declare the nature
of this invention and in what manner the same is to be performed to be
particularly described and ascertained in and by the following statement:-
The object of our invention is to provide an electric arc-lamp, in which two series
of carbons, contained in two supply-chambers move forward progressively and
successively, in proportion to the wear, under the action of an automatic arc-
regulator.
In the annexed drawing, one form of construction of the lamp embodying our
invention is illustrated.
Figure 1, is a lateral elevation of the lamp it being supposed that the cover is
cut away in order that the interior may be exposed to view; for the purpose of
greater clearness the conducting wires are illustrated schematically.
Figure 2, is an end view the cover of the lamp being also in section.
The supply-chambers and the regulator are contained in a cover A of any
suitable forin and construction, preferably of sheet iron, furnished with a suspension
eye bolt a and terminals a¹ and a². The ash-pit B which supports the globe C is
attached to the cover A.
The supply-chambers D, D, which may be constructed in any suitable manner
are preferably formed like rectangular frames or boxes in which the carbons E
may be stored, the movable coverings d being employed in order that the carbons
can be inserted in said frames. The carbons may be of any form or length
whatever. They are placed side by side in the supply-chambers. Each carbon is
provided at one end with a point preferably somewhat conical and at the other with
a corresponding hole el intended to receive the point of the adjoining carbon as will
be explained hereinafter. The carbons of each supply-chamber are placed under
the action of a piston F attached by a wire f to a spiral spring 1 fastened to the
cover, the action of the piston F is such that when the first carbon E of each
supply-chamber supported against the side or wall of the latter goes completely
through the aperture d' formed in the bottom of the frame or box D in the manner
that will be specified later on, the following carbon E2 immediately takes its place
against the side or wall d².
As a matter of course the piston might be constructed in any other manner
suitable for producing the specified result.
The first carbon of each box is drawn automatically from its supply-chamber by
the arc-regulator whose function it is, at the same time to keep at the proper
distance the two points of the carbons E³, E³, between which the current produces
the voltaic arc, these points penetrating into the globe C through the
apertures a³, a³ of the cover A.
Each carbon E passes through a double solenoid formed of coarse wire at G
and of fine wire at H. These solenoids are fixed for example, to the rectangular
pieces I, I, screwed on the bottoms of the supply-chambers. The action of these
solenoids will be explained further on. Their hollow cores or centres G' and H¹

page_text: through which the carbons freely pass are each furnished with a sort of vice or
clamp arrangement preferably formed as follows:-
Each vice or clamp arrangement is composed of two jaws J, J, of suitable shape
for clasping the carbon and each attached to a rod K on which is a spiral spring k
and which is connected by a universal joint L to the coil of the double
solenoid G, H. In each vice or clamp arrangement the spring-rods K are each
attached by means of a small rod M to a screw N screwed on the centre G₁or H¹
of each solenoid G or H. The tension of each spring k may be regulated by means
of a screw P screwed on the rod K, the length of the rod K itself is regulated by
means of a screw R.
Another solenoid S mounted in deviation on the arc is fixed in any suitable
manner to the cover A. The core or centre S* controlled by a screw S¹ belonging
to this solenoid acts on an armature S2 which is under the action of a spring S® and
is capable of turning around the pivot S³. This armature carries a contact piece S
preferably formed as a screw, capable of control as regards its position, which
during the oscillation of the armature S2 is able to come in contact either with the
contact-piece T or the opposite contact-piece U which are respectively mounted on
the plate springs t and u, electrically connected with the other parts as about to he
spoken of. Further the manner of effecting the insulations and the electrical
connections will be clearly seen by persons skilled in the art from the description
that we are about to give of the action of our lamp, and which will enable us at
the same time to shew the principal advantages secured thereby.
Supposing the supply-chambers D to be freshly filled with carbons, with their
points all on the same side and their holes on the other side; the first carbon E³
being already pinned or slipped on to the following carbon E', supposing further
that the electric current is introduced into the apparatus, this current will reach
the carbons E3 E3 through the supply-chambers D which are insulated at their
upper parts from the body or frame of the lamp. The carbons E are thus in
contact through their points. The solenoids of coarse wire G which are mounted
in series in the are are then traversed by a current the circuit of which is indicated
in the drawing by the line of heavy dots and dashes V. The centres G¹ are thus
attracted upward from below and through the medium of the small rods M close
the jaws JJ of the vice or clamp arrangements, which hold firmly between them
the carbon which they surround, and thus compel the carbon to follow the
ascending movement of the centre G¹. The points of the carbons thus come apart
and the lighting of the lamp is effected. The length of the arc is regulated, in
connection with the illumination, by means of screws N. In the drawing Z
indicates a buffer preferably of marble and asbestos intended as a support for the
carbons when the lamp is not in active use.
When the arc begins to lengthen the solenoid of fine wire S, having a suitable
resistance and placed as we have said in derivation on the are and comprising in
its circuit (indicated in the drawings by the line of fine dots and dashes X) the
contact U attracts the armature S2 the contact screw S* then comes in contact
with the electric contact T and closes the current in the solenoids H, H. The
centres H'H' are then attracted downwards from above, the clamp arrangements
attached to these centres act as previously stated, in regard to those of the
centres G¹ that is to say, close tightly in descending, draw the carbons from the
supply-chambers, and at the same time push the carbons placed in front. When
the centres H, H' reach the end of their course the armature S2 cuts off the
current from the solenoids H, H, first by the contact T and its insulated spring,
second by the contact U and its insulated spring; the centres H1, H¹ ascend again
and the clamps unlock under the action of the springs k. The alternating movement
of the clamps drawing and pushing the carbons ceases when the potential fall has
become normal again.
During the lengthening of the arc and the descending movement of the carbons
which is effected by the solenoids H, H, the magnetism of the cores or
centres G¹ G¹ becomes weakened, these cores or centres descend under the action

page_text: of the springs of the corresponding clamp arrangements which unlock and allow
the carbons to slide insensibly or gently under the pressure of the clamps of the
solenoids H, H. The action of these last, is slightly in advance of that of the
solenoids G G so that the pressure of the clamps above is felt or occurs a little
before the action of the solenoids G G completely unlock the cramps below. The
carbons thus come together very gently whilst the pinning or slipping of the one
on to the other is always perfect, the act of pushing being always slightly in
advance of the descent which is modified by the action of the solenoids G G.
This control is effected by means of the screw S' of the core or centre S* belonging
to the solenoid S which moves away from or draws near to the core or centre of
the armature and retards or hastens the action of the solenoid S acting on the
solenoids H H.
From what precedes it will be seen how the clamps above draw the first carbon E
out of the supply-chamber in proportion to the wearing of the points of the
carbons E³. When one of these carbons E' has been completely drawn out of the
supply-chamber the following carbon E' immediately takes its place under the action
of the piston F. The action of the upper clamp draws it in its turn and the combined
action of the upper and lower clamps pin it, or slip it on to the preceding carbon by
forcing the pointe of the one into the corresponding hole el of the other. This
pinning or slipping on is so firmly effected that the two carbons hold together as
if forming one piece.
It will be seen that the regulator of our system presents the advantage, that
should one or both points E³, E³ become broken the regulator will act, so as to
bring the carbons to the proper position without interruption to the illumination.
On the other hand the application of supply-chambers in an arc-lamp is a
new idea which allows of the effecting of great saving in hand-labor in
consequence of the continual replacing of carbons one at the time, being done
away with.
Again the combination of the supply-chambers and our regulator enabling a
large series of carbons to be pinned or slipped on to one another effects a great
saving of carbons and which considering the price of these is of considerable
importance.
In conclusion we would observe that our lamp can be worked with currents
of any nature. If the current is alternating the carbons of each supply-
chamber will be of equal length if the current on the contrary is continuous,
one of the supply-chambers will be supplied with carbons twice as long as
the other.
In fact our lamp combines all the qualities that can be fairly expected in an
apparatus of this kind, simplicity of construction, saving of hand-labor and of
material, absolute regularity of action and automatic relighting in case of breakage
of the points or accidental extinction.
It is also evident that we are in no way restricted to the particular form
of construction illustrated in the drawing (which moreover we only give by
way of practical example), that we may on the contrary alter the constructional
arrangements as we may desire without passing beyond the scope of our
invention.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
clain is:
Firstly. An electric arc-lamp with supply-chambers for the carbons.
Secondly. An electric arc-lamp with regulator so constructed as to draw, push,
and regulate the carbons automatically during working to allow of illumination or
lighting.
Thirdly. An electric arc-lamp with supply-chambers in which the carbons are
drawn from their supply-chambers and welded on to the preceding carbons end to
end by the action of the regulator.

page_text: Fourthly. The form of construction of the supply-chambers as described and
illustrated in the drawings.
Fifthly. The form of construction of the regulator as described and illustrated
in the drawings.
Sixthly. The electric lamp substantially as herein described and as illustrated.
Dated the 22nd J. of Dah 1007
W. D. ROWLINGSON,
7 Quality Court, Chancery Lane, London, W.C.,
Agent for the Applicants.