Improvements in Appliances for Increasing the Duration of the Top. Carbon of Electric Arc Lamps.
Year: 1894

page_text: Date of Application, 23rd Apr., 1894
Complete Specification Left, 8th Jan., 1895-Accepted, 9th Feb., 1895
PROVISIONAL SPECIFICATION.
Improvements in Appliances for Increasing the Duration of the Top.
Carbon of Electric Arc Lamps.
We, FRANCIS JEHL Electrical Engineer and FRITZ VON HARDTMUTH
Manufacturer both of XIX Schegargasse No. I Vienna, Austria, do hereby
declare the nature of this invention to be as follows:-
This invention relates to improvements in appliances for increasing the duration.
of the top carbon of electric arc lamps, by means of a protecting sleeve of
refractory material which tightly encloses this carbon without allowing the passage
of air.
Experiences have shown that such protecting sleeves as employed hitherto have
the inconvenience of being easily deteriorated by the action of the illuminating arc
and of being consequently destroyed after a certain time, the whole apparatus thus
becoming unfit for its purpose and useless. This especially takes place when the
carbon is of small diameter, owing to the proximity, in that case, of the illuminating
are to the protecting sleeve.
The improvements to which the present invention relates have for their object to
obviate the said inconveniences inseparable from such apparatus, without losing
any of the advantages resulting from their use.
For that purpose, the protecting sleeve of non-conducting refractory material or
of conducting, fire resisting material, which in the latter case is insulated from the
carbon, is bored out on a suitable part of its length, or else is encompassed by a
second sleeve, projecting to a suitable length beyond the former, in such a manner
that, after the appliance has been inserted on the carbon, that part of the latter
which is subjected to combustion is surrounded by an annular vacant space
enclosed within the lower part of the sleeve and closed above by that part of
the sleeve which tightly surrounds the carbon without air-clearance.
Owing to this arrangement, there is formed between the incandescent extremity
of the carbon and the protecting part of the sleeve a quiescent air jacket, receiving
the gaseous products of the combustion generated by the arc, and preventing, on
one hand, the carrying away and burning off of carbon particles from the periphery
of the carbon, and on the other hand the deterioration of the sleeve.
This apparatus for protecting the top carbon is advantageously combined with a
supporting device which, during the successive lowering of the top carbon, caused
by the feeding action of the regulator, automatically adjusts the position of the
protecting sleeve in proportion as the carbon is consumed, and which prevents the
falling of the appliance in case of breakage of the lower carbon.
The sleeve may however also be connected to a supporting device resting on
the lower carbon and lowered in the same measure as the latter is consumed by
combustion.
In both cases, the supporting devices allow of the keeping of the carbons at a
certain arc-distance apart.
The accompanying drawings show the apparatus for increasing the duration of
combustion of the top carbon, in two modifications.
As shown, the protecting sleeve a of non-conducting refractory material, steatite
for instance, or of other fire resisting material, if necessary insulated from the

page_text: carbon, is fitted upon the top carbon k, without any air clearance, and has its lower
part a' close to the end of the carbon, bored to a larger internal diameter on a
suitable length (Fig. 1) or else this sleeve a is enclosed by a second sleeve a
suitably projecting beyond the lower end of the former, towards the end of the
carbon (Fig. 2) in such a manner that in both cases an annular space is formed
between the carbon and the lower sleere portion (or a²) which is neither
mechanically nor electrically connected to the said carbon.
The lower part of carbon is thus surrounded by an air jacket interposed
between the illuminating arc and the lower portion a' or a' of the sleeve.
Since the sleeve a itself surrounds the carbon tightly, there cannot be any motion
of the air and the gaseous products of combustion generated by the illuminating
arc, within the annular space b.
The mixture of gas and air forms rather an elastic cushion of constant
temperature and therefore produces the same effects as a sleeve that would enclose
the extremity of the carbon; it thus prevents the end of the carbon from assuming
a conical shape whilst burning and thus increases the duration of the combustion,
whilst at the same time it prevents the deformation or deterioration of the
protecting sleeve.
In order to maintain this sleeve a constantly in the required position with
relation to the carbon k fed forward by the regulator, the sleeve is enclosed by a
ring c or is inserted by means of a supporting socket c' into the said ring, which
rests by means of lateral arms c³ on the adjusting nuts d screwed on the ends of a
bow f.
In the construction shown in Fig. 1, the bow fis connected to a ring f' fitting
the conical end of the lower carbon k', whereas the protecting sleeve a carries two
spring clips 9 which press against the top carbon k.
Before the arc is formed, the ring frests on the lower of the two contiguous
carbons. On the circuit being closed, the top carbon is raised by the regulator to
the extent corresponding to the length of the arc, and carries along with it the
⚫ protecting sleeve a and the bow f, owing to the action of the spring clips g; the
ring is thus raised off the lower carbon k'.
During the combustion the top carbon is fed forward by the regulator in a well
known manner, the sleeve a partakes of this motion but only until the moment
when the ring of the bow f, which is also carried along, again rests on the lower
carbon k¹.
Since, by means of the adjusting nuts d, the protecting sleeve a can be regulated
according to the arc-length, this sleeve will move in proportion to the combustion
of the carbons but without the whole appliance being supported by the lower
carbon.
This arrangement has the advantage that in case of breakage of the lower
carbon, the protecting sleeve remains suspended from the top carbon by the spring
clips g, the whole appliance thus being prevented from falling.
In the construction shown in Fig. 2 the bow that supports the protecting
sleeve a is connected to another protecting socket for the lower carbon k', which
socket is supported in the known manner by a ring h¹ resting on the conical end of
the said carbon, in such a manner that the whole appliance is lowered as the lower
carbon is consumed.
h'
As in the previous case, the adjusting for a determined arc-length may be
effected either by means of the adjusting nuts d, or by means of a device according
to which the protecting socket for the lower carbon is threaded externally and
receives a threaded nut which is therefore capable of being raised or lowered on
the socket, this nut being rigidly connected to the bow /.
Lock nuts d' may be screwed on the ends of the bow f'in order to insure the
steadiness of the arms supporting the ring c.
Dated this 23rd day of April 1894
ABEL & IMRAY,
Agents for the Applicant.

page_text: Improvements in Appliances for Increasing the Duration of the Top
Carbon of Electric Arc Lamps.
We, FRANCIS JEHL Electrical Engineer and FRITZ VON HARDTMUTH..
Manufacturer, both of XIX Skagargasse No. I Vienna, Austria, do hereby
declare the nature of this invention and in what manner the same is to he
performed to be particularly described and ascertained in and by the following
statement :-
This invention relates to improvements in appliances for increasing the duration
of the top carbon of electric arc lamps, by means of a protecting sleeve of
refractory inaterial which tightly encloses this carbon without allowing the passage
of air.
Experiences have shewn that such protecting sleeves as employed hitherto have
the inconvenience of being easily deteriorated by the action of the illuminating are
and of being consequently destroyed after a certain time, the whole apparatus thus
becoming unfit for its purpose and useless. This especially takes place when the
carbon is of small diameter, owing to the proximity, in that case, of the illuminating
are to the protecting sleeve.
The improvements to which the present invention relates have for their object
to obviate the said inconveniences inseparable from such apparatus, without losing
any of the advantages resulting from their use.
For that purpose, the protecting sleeve of non-conducting refractory material or
of conducting, fire resisting material, which in the latter case is insulated from the
carbon, is bored out on a suitable part of its length, or else is encompassed by a
second sleeve, projecting to a suitable length beyond the former, in such a manner
that, after the appliance has been inserted on the carbon, that part of the latter
which is subjected to combustion is surrounded by an annular vacant space enclosed
within the lower part of the sleeve and closed above by that part of the sleeve
which tightly surrounds the carbon without air-clearance.
Owing to this arrangement, there is formed between the incandescent extremity
of the carbon and the protecting part of the sleeve a quiescent air jacket, receiving
the gaseous products of the combustion generated by the arc, and preventing, on
one hand the carrying away and burning off of carbon particles from the periphery
of the carbon, and on the other hand the deterioration of the sleeve.
This apparatus for protecting the top carbon is advantageously combined with a
supporting device which, during the successive lowering of the top carbon, caused
by the feeding action of the regulator, automatically adjusts the position of the
protecting sleeve in proportion as the carbon is consumed, and which prevents the
falling of the appliance in case of breakage of the lower carbon.
The sleeve may however also be connected to a supporting device resting on
the lower carbon and lowered in the same measure as the latter is consumed by
combustion.
In both cases, the supporting devices allow of the keeping of the carbons at a
certain arc-distance apart.
The drawings accompanying our Provisional Specification show the apparatus
for increasing the duration of combustion of the top carbon, in two modifications.
As shown, the protecting sleeve a of non-conducting refractory material, steatite
for instance, or of other fire resisting material, if necessary insulated from the carbon,
is fitted upon the top carbon k, without any air clearance, and has its lower part a¹
close to the end of the carbon, bered to a larger internal diameter on a suitable
length (Fig. 1) or else this sleeve a is enclosed by a second sleeve a suitably
projecting beyond the lower end of the former, towards the end of the carbon

page_text: "
3
(Fig. 2) in such a manner that in both cases an annular space b is formed between
the carbon and the lower sleeve portion a¹ (or a²) which is neither mechanically
nor electrically connected to the said carbon.
The lower part of carbon k is thus surrounded by an air jacket interposed
between the illuminating arc and the lower portion a¹ or a³ of the sleeve.
Since the sleeve a itself surrounds the carbon tightly, there cannot be any motion
of the air and the gaseous-products. of combustion-generated by the illuminating
are, within the annular space b.
The mixture of gas and air forms rather an elastic cushion of constant
temperature and therefore produces the same effects as a sleeve that would enclose
the extremity of the carbon; it thus prevents the end of the carbon from assuming
a conical shape whilst burning and thus increases the duration of the combustion,
whilst at the same time it prevents the deformation or deterioration of the
protecting sleeve.
In order to maintain this sleeve a constantly in the required position with
relation to the carbon k fed forward by the regulator, the sleeve is enclosed by a
ring c or is inserted by means of a supporting socket c¹ into the said ring, which
rests by means of lateral arms c² on the adjusting nuts & screwed on the ends of a
bow f.
In the construction shewn in Fig. 1, the bow fis connected to a ring f1 fitting
the conical end of the lower carbon k', whereas the protecting sleeve a carries two
spring clips which press against the top carbon k.
Before the arc is formed, the ring frests on the lower of the two contiguous
carbons. On the circuit being closed, the top carbon is raised by the regulator to
the extent corresponding to the length of the arc, and carries along with it the
protecting sleeve a and the bow f, owing to the action of the spring clips g; the
ring is thus.raised off the lower carbon k'.
During the combustion the top carbon is fed forward by the regulator in a well
known manner, the sleeve a partakes of this motion but only until the moment
when the ring of the bow which is also carried along, again rests on the lower
carbon kl.
Since, by means of the adjusting nuts d, the protecting sleeve a can be regulated
according to the arc-length, this sleeve will move in proportion to the combustion
of the carbons but without the whole appliance being supported by the lower
carbon.
This arrangement has the advantage that in case of breakage of the lower
carbon, the protecting sleeve remains suspended from the top carbon by the spring
clips g the whole appliance thus being prevented from falling.
In the construction shewn in Fig. 2 the bow f that supports the protecting
sleeve a is connected to another protecting socket for the lower carbon k', which
socket is supported in the known manner by a ring resting on the conical end of
the said carbon, in such a manner that the whole appliance is lowered as the lower
carbon is consumed.
As in the previous case, the adjusting for a determined arc-length may be
effected either by means of the adjusting nuts d, or by means of a device according
to which the protecting socket for the lower carbou is threaded externally and
receives a threaded nut which is therefore capable of being raised or lowered on
the socket, this nut being rigidly connected to the bow f.
Lock nuts d' may be screwed on the ends of the bowfin order to insure the
steadiness of the arms supporting the ring c.
Having now particularly described and ascertained the nature of this inven
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. An appliance for insuring the level burning away of the upper carbon of an
are lamp, consisting of a sleeve fitted on the said carbon so as to slide thereon, the
lower widened bore of which sleeve terminates in the same plane as the end surface

page_text: of the carbon, so that the end portion of the latter next the arc is surrounded by a
quiescent body of air or gas, substantially as described.
2. The combination with the sleeve referred to in the first claim of adjusting
screw nuts d for adjusting the carbons to a determined length of arc, the said
screw nuts being screwed on to a bow f carried by the lower carbon and supporting
a ring c carrying the sleeve, substantially as described.
Dated this 8th day of January 1895.
ABEL & IMKAI,
Agents for the Applicants.